Vision guide en 6 20 14

Vision Inspection Reduction of Product Defects Building an Effective Vision Inspection Program

Table of Contents

Page Number

Introduction to the Guide

2

Chapter 1: Introduction to Vision Inspection Programs

4

Chapter 2: Reasons for a Vision Inspection Program

8

Chapter 3: Key Design Features

12

Chapter 4: Factors Affecting Vision System Repeatability

14

Chapter 5: Introduction to How Vision Technology Works

16

Chapter 6: Building Blocks of a Vision Inspection Solution

22

Chapter 7: Importance of Product Handling

28

Chapter 8: Complete Vision Inspection Solutions

34

Chapter 9: Typical Vision Inspections for Packaging

38

Chapter 10: Building an Effective Vision Inspection Program

50

Chapter 11: Installation and Commissioning

62

Chapter 12: Performance Verification and Auditing

64

Chapter 13: Dealing with Suspect & Rejected Product

68

Chapter 14: Data Analysis & Program Improvement

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Summary 72 Appendix A: Comparing Vision Implementation Strategies

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Introduction to the Guide

Introduction to the Guide The purpose of this Guide

Strong brand reputation is an asset, which can easily be damaged by customer complaints, product safety concerns and product recalls. Vision technology is a great tool to help protect against these risks, but implementing hardware is not enough. When considering adding vision inspection hardware to a manufacturing facility, it is important to make sure that it gets implemented as part of an overall vision inspection program. If implemented correctly, a vision inspection program can help to protect and build strong brand reputation, both today and for the foreseeable future.

The primary purpose of this manual is to help companies decide which parts of a vision program they need, and which types of technology will best suit their process. The Guide contains a detailed summary of typical sources of product recalls which a vision program can help identify, followed by a detailed introduction to the vision technology available on the market today. The Guide then culminates in outlining the steps and aspects of building an effective vision inspection program that will help protect the consumer and the brand.

The vision inspection program described in this Guide is applicable to many types of manufacturing environments, although the primary focus is on manufacturing and packaging of consumer products in ISO-certified, HACCP (Hazard analysis critical control points) and pharmaceutical 21 CFR regulatory environments.

This guide provides a comprehensive reference point for those involved in wanting to eliminate defective products. The guide gives insight into all aspects from basic vision inspection principles through implementing a comprehensive vision inspection program.

Sections 1 and 2 provide an overview of the reasons for implementing a vision inspection solutions program.

Sections 3 to 6 go on to explain the various technologies involved with vision inspection systems. This includes how Vision Technology actually works, the building blocks of a vision inspection solution, best practices for product handling in combination with a vision inspection system, and what makes up a vision inspection solution.

Sections 7 to 14 explain proven ways to establish and utilize a vision inspection program. These sections will include demonstrations of typical inspections used on various packaging lines, ways to build an effective vision inspection program, how to deal with suspect and rejected product, and data analysis and program improvements.

Margin symbols appear throughout the guide to help draw the readers’ attention to points of note. The symbols and their meanings are described in Table 4 on the next page.

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Symbol

Meaning Warning - An operating practice that could result in the incorrect operation or use of the vision inspection system

Best Practice - An operating practice that can be considered best practice at time of publication

Record - Highlights pertinent records that should be generated and maintained in order to demonstrate the effective operation of the vision inspection programme HACCP - Hazard Analysis and Critical Control Points Highlights actions that will aid the implementation of an effective HACCP program

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1: Introduction to Vision Inspection Programs 4

Chapter 1 Introduction to Vision Inspection Programs A vision inspection program is a valuable tool for manufacturing, assembly or packaging operations. Its ability to detect defects, and prevent defective product from being distributed to consumers is invaluable. In recent years, retailers and consumers have become much less patient with poor product quality that leads to either health risks or increased retailer costs. If a vision inspection program is correctly implemented, and managed it can become a powerful tool to • Protect the manufacturer, retailer and consumers from mislabelled packages and unidentified allergens • Help to protect the reputation of brand • Adhere to industry best practice guidelines and retailers standards Research shows that 65% of consumers refer to the packaging when buying products.

If the package is mislabeled or the label is damaged, concealing a potentially harmful ingredient, this can lead to a product recall, fine or even a lawsuit. PackagingWorld. com confirms that 55% of food industry recalls are caused by improper labelling. A very common example is food allergens.

As a result, most companies that have established product inspection programs, that originally relied on human inspectors, are implementing vision inspection programs.

Vision inspection programs can detect and reject defective products, including those not completely filled or with incorrect or wrinkled labels and cocked caps, before they go out the door. These systems never blink, never tire and are able to detect 100% of the defects they are programmed to capture, virtually ensuring that a defective product will never reach a consumer.

This manual summaries the types of technologies available and details the main things a manufacturer should consider when implementing a vision inspection program.

While reviewing this manual, it is important to keep in mind that a vision inspection program gives the manufacturer the capability to

There are 3 ways to implement a vision inspection program

Do it your self (DIY) Use a systems integrator Buy the system from a vision inspection solution provider

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Compare packaging on the production line to ideal images and reject mismatches Measure product dimensions and reject out-of -tolerance product Read data on products to verify that correct data is shown and is printed to acceptable quality standards.

Count the number of products in a case or package and reject it if there is too few or too many items

While every vision inspection system performs essential functions, most customers require some level of customization in development and should be cautious of vendors claiming to have “one-size-fits-all” solutions.

Systems perform best in their own tightly-controlled, highly-specialized environment.

The “make-or-buy” Decision Once manufacturers determine that they require a vision inspection program they must decide the best path to take to implement the program. Larger companies with skilled engineering staffs may pursue their own solution, assembling components purchased from various vendors or even using new technology. However, a steep learning curve, lack of industry standards and time-to-market pressures make the in-house approach largely impractical.

The vision system meant to add value to a production line can become a serious drain on time, energy and resources. Expert help may need to be called in to solve the problem.

Many manufacturers look to outsource because many companies find that purchasing a vision inspection system entails less risk than designing and manufacturing it themselves. System integrators and vision inspection solution providers have the integration expertise necessary to provide application-specific solutions based on a thorough review of the requirements, allowing them to focus their attention on specific customer needs. A vision inspection solution refers to a complete vision implementation including all analysis, engineering, equipment, software, installation, services and documentation.

Even then, putting together pieces from a variety of component vendors remains a costly, time-consuming task. According to industry analyst Nello Zeuch of the Automated Imaging Association, the cost of components accounts for less than one-third the cost of a vision inspection program. The majority of the cost goes towards the other aspects of equipment design, program testing, installation, and integration, discussed in further chapters.

Moreover, the real costs of product development often hide in the lost opportunity cost of not getting a product to market on time. Studies show that, in today's fast-paced markets, the opportunity cost of a six-month delay in product development can far exceed both a 50% development cost overrun and a 10% increase in manufacturing costs.

With the help of an experienced system integrator or vision inspection solution supplier, schedules are more likely to be met, because they have extensive experience implementing a vision inspection program.

Having the support of an outside company after the solutions is delivered adds another advantage. Many manufacturers’ don't have the in-house service support required to get a system back up and running should problems arise. Nor do they have the expertise necessary to upgrade the system later with newer technology. A capable solution supplier should be able to provide an invaluable source of technical assistance and advice, for the life of the equipment.

Vision Inspection History From its roots in early research into artificial intelligence in the 1940s, vision inspection is now an essential component of industrial processes as diverse as semiconductor manufacturing, pharmaceutical packing, package quality inspection, and automobile manufacturing—even checking for missing screws in flat-pack furniture kits!

See Vision Inspection Time line on page 6 to view a brief history of the technology.

Image processing is the heart of a vision inspection systems and has established itself as a versatile, user-friendly and economical tool for quality control in virtually all areas of industry. Unlike the human eye, vision inspection systems can perform checks with 100% constant quality—around the clock.

Comparing Implementation Techniques There are three ways for a manufacturer to implement a vision inspection program

Do it your self (DIY) Use a systems integrator Buy the system from a vision inspection solution provider

It is important for a manufacturer to be aware of the range of tasks and potential pitfalls when implementing a vision inspection program. The team responsible for the implementation should go into such a project with a full understanding of all the aspects involved in a successful implementation, making sure that it is delivered on time, and matching both the short term and long term expectations. Please see Appendix A for a list of activities that a successful implementation of vision system program entails and an assessment of the manufacturers, integrators and a inspection solution suppliers to implement them.

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1: Introduction to Vision Inspection Programs

Vision Inspection History Timeline

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Notes

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2: Reasons for a Vision Inspection Program

Chapter 2 Reasons for a Vision Inspection Program When evaluating if a vision inspection program will bring value, it is important to keep focused on the reasons your organization is implementing it. This chapter summarizes the value that a vision inspection program can bring a manufacturer.

Justification of the purchase and implementation of a well-designed vision inspection program are summarized as follows:

It minimizes quality defects Helps to protects the customer and consumer Protects a companies’ brand and reputation Return on investment (ROI) Supports adherence to industry best practice guidelines and industry standards Minimize the risk and impact of product recalls and returns

2.2 Protection of the Customer and Consumer Modern manufacturing techniques are constantly improving to eliminate quality defects, although there is always a risk that the processes or procedures can break down, resulting in defective products reaching the market.

Each of these are discussed in more detail in this chapter.

Manufacturers and their employees have an obligation to their customers and the end consumer to minimize these instances, ensure consistent quality and take all possible steps to protect the welfare of the end user. This proactive approach to quality management will also go a long way to support improved relationships with retailers and protect future business opportunities.

2.1 Minimizing Quality Defects

2.3 Protection of Brand and Reputation

Dealing with quality problems on the production line can cause losses of output, particularly on high volume automated production lines. However, such costs can be easily overshadowed by ramifications of defective product being discovered by the customer or consumer, causing product recall, damage to the brand, adverse publicity, and potential legal action.

Strong product branding gives retailers and consumers a perceived assurance of safety and quality. Branding is frequently responsible for driving consumer repeat purchases and, as such, is an important tool to maximize sales and to justify premium product pricing for manufacturers and retailers.

Time and money spent reducing internal waste, loss of output, and reducing complaints inevitably yields a better return than money spent answering them. A correctlyimplemented vision inspection program will lead to reduced defective product costs and improved customer and consumer satisfaction, leading to higher profitability and protection of the manufacturer's brand.

For this reason, an organization’s responsibility is not only to protect the end consumer but also the brand and the ongoing reputation of the company. Product brands are important assets to be managed carefully and need to be protected from any form of adverse publicity. Defective product in the hands of consumers can have a serious negative impact on any organization resulting in damage to the brand and potentially costly recalls.

In the event of a company being investigated as a result of a customer complaint, documentation will provide

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invaluable evidence that the manufacturer had the correct protection program in place.

important to keep in mind potential changes to the product, allowing maximum opportunity for the solution provider to build in flexibility to optimize for a long term ROI.

2.4 Return on Investment Implementing an effective vision inspection program can also offer a quick, positive return on the investment (ROI) made when implementing it. The main areas to address when calculating the ROI include

Reducing number of product recalls and returns Avoid retailer fines for delivering defective product Reduction in staff to visually inspect product

Avoiding fines and reducing the number of product recalls are returns which are difficult to calculate. In some facilities these are a frequent occurrence and in some these rarely happen. So typically when calculating an ROI these are intangibles which don't get considered. Suffice to say that these are added financial benefits of making sure your vision inspection program is installed and managed effectively.

Savings in the cost of staff is a simpler calculation for ROI (see table below) When a vision inspection program has been designed and set up for the inspections it is purchased for, the benefit it offers will continue year after year. Manufacturers should be aware that changes to products and packaging over time can make some systems quickly obsolete, reducing the impact of the ROI calculations. When specifying a vision inspection system it is

2.5 Adherence to Industry Best Practice and Industry Standards There are no legal requirements for manufacturers to install vision systems. Although, if legal action is taken against a manufacturer as a result of a mislabelled product, the vision system can be an invaluable tool to help prove that the manufacturer has taken due diligence in its processes.

Failure to do so could result in serious consequences.

Due diligence is easier to prove when an organization has a documented system which continually assesses the risks to food safety and allocates resources to minimize these risks.

Vision inspection systems are a quality tool, which are often the focus of customer / retailer audit, especially if they are used as a CCP in a HACCP program. The benefit of having a vision system as part of a wider program is that all the required documentation will already be in place to provide evidence that the system is being used correctly and as part of the factory wide quality program. Auditing groups which will benefit from a fully documented program are:

Internal food safety and management system audits Retailer audits Quality management system audits e.g. ISO9001:2000

Vision System Return on Investment Calculator ITEM

Enter your data

A

Parts per minute produced

B

Hours of production per day

C

Days of production per week

D

Average fully burdened hourly rate of inspectors

E

Number of inspectors

Sample Data 500 8 5 $18.00 1

F

Estimated defects as a percentage of PPW *

1.0%

G

Additional finishing costs to products (packaging, additional processing, assembly etc) **

$0.10

H

Dollars spent on Vision system

$70,000.00

* This calculation conservatively assumes no difference in percent defects identified between human and vision system.

In actuality, a vision system will identify 100% of defects it is programmed to identify - significantly more then a fatigued inspector on a high speed line. ** This calculation assumes that products deemed to be rejected have incurred the full finishing costs.

Production per week (PPW) = A x 60 x B x C Inspection Cost per week (ICPW) = B x C x D x E Cash added each week to flawed products (CAFP) = PPW x F x G

1,200,000 parts $600.00 $1,200.00

ROI (Return on Investment) in weeks ROI calculated by added cost to flawed products = H / CAFP ROI calculated by cost of inspectors = H / ICPW ROI for both cost and labor savings = H / (CAFP + ICPW)

66.7 Weeks 133.3 Weeks 44.4 Weeks

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2: Reasons for a Vision Inspection Program

HACCP audits, including BRC, IFS, SQF 2000, and ISO 22000

2.6 Minimize the Risk and Impact of Product Recalls and Returns The consequences of defective product reaching consumers are increasing all the time. Consumers are increasingly taking legal action when they find it, or they contact the media. As a result the retailers are also taking their own precaution, in terms of fines for the manufacturers. Then the manufacturer on top of that is also responsible for the costs of getting the product out of the market. All of these

consequences can be devastating to a manufacturer's short and long term business. (See recall notice below) An effectively installed and managed vision inspection program can go a long way to help manufacturers prevent defective product from reaching the market. The range of defects that a vision system can detect are large ( see chapter 8). The key is that a vision system is now able to inspect 100% of products at real time and reject the product which is defective, preventing them from reaching the market.

Typical FDA Recall Notice Announce Voluntary Recall due to Incomplete Allergen Labeling WEDNESDAY, 05 MAY 2010 07:30 PRESS RELEASE RECALLS OHIO – (ENEWSPF) – May 5, 2010. Initiating a voluntary recall of select boxes of Product X because the outer containers of some of the boxes were distributed without a complete allergen precautionary statement. Consumers who have allergies to peanuts run the risk of serious or life threatening allergic reactions if they consume products containing peanuts.

The boxes of Product X are seasonal items distributed nationwide in supermarkets and club stores. The only products involved in the voluntary recall include Box Product X distributed during the 2009 holiday season with day codes beginning with 9XXX through 9XXX, and a “Best By” date of June/July 2010. The UPC codes for the affected products are 5XXXX-6XXXX for the retail version, and 5XXXX-6XXXX for the club store version. No other products are impacted by this recall.

The components contained in the boxes were completely labeled, including a precautionary statement on one component stating “made in a facility that also processes peanuts”. However, the outer containers of some of the boxes were distributed without a complete precautionary statement. As the health and safety of our consumers is paramount, we are initiating this voluntary recall. We have advised the U.S. Food and Drug Administration and will cooperate with them fully in this voluntary recall. Providing safe, high quality products to our consumers is our number one priority.

Consumers who are allergic to peanuts and who have purchased the recalled products are advised not to consume them. Instead, they ask these consumers to contact Consumer Services directly for instructions. Consumers should not return Product X to retailers.

Consumers with questions should contact Consumer Services at and/or visit their web site .

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Notes

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3: Key Design Features

Chapter 3 Key Design Features In the event of a vision inspection solution failure, will a manufacturer stop production until a service engineer visit can be scheduled or continue to run the production line with the risk of a quality issue or label mixup being introduced? The chances of facing this dilemma can be significantly reduced by selecting the most reliable vision inspection solution. This chapter provides valuable information on some of the key considerations when selecting a vision inspection solution.

Selecting a reliable vision inspection solution is a key step towards minimizing or eliminating the incidence of mixed up labels or low quality product reaching the market. There are few guidelines available to help users compare and evaluate the capabilities of different technologies. This chapter aims to provide practical guidance on the design features that can readily make a difference in the long-term experience of running effective vision inspection programs. Avoiding erratic detection, complexity of set-up, and random false rejects are the key factors which will make a difference in the success or failure of the overall vision inspection program.

Vision inspection solutions can be frustrating to production personnel when they appear to operate inconsistently.

They will quickly lose confidence in a solution that rejects product which is subsequently shown to be good or one that requires constant attention for the sensitivity standard to be maintained. A solution which is capable of giving consistent, reliable detection and rejection, without the frustration of false rejection, will win the confidence of both line operators and management and provide the best protection long-term. Actual "production line" sensitivity is the measure which takes all these factors into account.

Stability This is the distinguishing factor of a top quality vision inspection solution and highlights the difference between sensitivity and performance. Performance is a measure of equipment capability under real plant conditions. A stable vision inspection solution is able to operate consistently without false rejects or erratic detections and should not require periodic adjustment. Most solutions when tested in a laboratory will give similar sensitivity levels side by side. However, over an extended period on a production line, significant differences may well become evident. An unstable solution, particularly when linked to an automatic reject device, can quickly become a focus of criticism.

Repeatability In addition to false rejections, instability may cause the detection level to vary over time. Having a solution that detects the test sample repeatedly each time it is used, over a period of weeks or months instills confidence in the user. It also avoids the problems of having defective product pass undetected.

Ease of Set-up

3.1 Design for the Production Environment Modern vision inspection solutions benefit from ever increasing processing power, broadening the range and number of inspections they can perform. It is important that these additional capabilities don’t make the solution unstable and ineffective in day to day operation in the production environment.

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A vision inspection solution which has a complex or confusing set-up procedure inevitably will not be adjusted correctly. After initial training, it should be practical for the user to adjust all parameters without reference to an instruction manual. A logical procedure and an intuitive Human Machine Interface (HMI) avoids having to memorize special sequences and will mean changes can be properly made long after the initial training is given.

Flexible design One of the significant benefits of using a complete vision inspection solution is that they are designed with modular components and flexible frames. This significantly reduces the cost of lost production time due to maintenance/repair and product change over.

3.2 Vision Inspection Solution Mechanical Design Environmental Protection The selection of the vision inspection solution should be commensurate with the hygiene requirements of the product and the environment in which it will operate. If the product is high-risk then the vision inspection solution should be constructed to withstand harsh conditions, deep cleaning and sterilization routines. For producers of meat, poultry, dairy and similar products, a vision inspection solution’s inability to withstand frequent heavy duty wash-down is a common problem. The repair of a vision inspection solution that has water ingress is both expensive and time consuming. System performance should remain unaffected when equipment is situated in any areas subject to water or steam (providing it is correctly specified at time of purchase). If a vision inspection solution is to be used in a designated potentially explosive environment, then the solution should be independently certified by an accredited recognized body and the solution manufacturer approved to make and sell such a solution.

unstable, the inspection will be compromised. The vision inspection solution provider should take these things into consideration when developing the solution’s conveyor. (see chapter 7 for more detail) 3.4 Reject Mechanism Design Ineffective reject systems are probably the weakest part of most vision inspection solutions and result in defective product not being effectively and reliably rejected from the production line. A correctly specified solution should be foolproof and capable of rejecting all defective product under all circumstances, independent of the frequency of defective products. See Chapter 4 for further details.

3.5 Hygienic Design All vision inspection solutions should be designed with due consideration to the environment in which they will operate and the cleaning regimes likely to be encountered. Hygienic design principles should be applied to every aspect of the system to eliminate dirt traps and facilitate easy cleaning.

Design features should include:

The elimination of cavities/bacterial traps The sealing of all hollow sections Avoidance of ledges and horizontal surfaces The use of open design, continuous welded frames for easy access and cleaning Hygienic management of electrical cables, trunking and pneumatic services

Vibration and Ambient Light Immunity

3.6 Health and Safety

Every vision inspection solution uses light to create contrast between the inspected area and the back ground. If the lighting is interfered with by ambient lighting or changing lighting environments, the solution will struggle to operate effectively. In addition, if there is movement of the product in relation to the cameras in unplanned ways this will lead to false rejects or defects not being rejected. This is obviously an undesirable situation; therefore mechanical design and the solution’s protection against ambient lighting are equally as important as the electronics design in preventing this. Solutions that don’t have protection from ambient lighting and product handling will have to be frequently monitored to ensure that they are operating effectively.

Health and Safety is an important consideration. Design and build of a vision inspection solution should be certified as being in accordance with statutory regulations and standards in force at the time of sale. For example, CE marking in relation to applicable machinery safety standards will minimize the risk of an employee being hurt. Any such injuries could result in costly personal injury claims.

3.3 Conveyor System Design Proper product presentation to the cameras in the vision inspection solution is critical to ensure the inspection is taking place correctly. If the product is unorientated, doesn’t display the inspected area consistently or the product is

3.7 Failsafe Solution Design Consideration should be given to the implications of the failure of a system to function as intended. As an example, a reject device does not remove defective product or a fault occurs within the vision inspection solution. It is considered good practice to integrate failsafe design features into the vision inspection solution to mitigate the risks associated with system malfunction. For example, reject confirmation systems can be used to confirm that the defective product has been rejected into the reject bin.

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4: Factors Affecting Vision System Repeatability

Chapter 4 Factors Affecting Vision System Repeatability External factors influence the repeatability of a vision system’s measurements in predictable ways.

This chapter highlights the most important of these external factors and how their effects can be controlled in order to ensure that purchased equipment will meet its operational specifications.

Statistical Repeatability is a quantitative measure of the suitability of a measuring system for a particular application.

For example, a carpenter’s tape measure accurate to +/- 2 mm is suited to the requirements of fitting boards together to build a house, while being unsuitable for measuring parts in a typical machine shop, where micrometers accurate to +/- 0.01 mm are required to measure critical machined part dimensions.

Many factors influence the actual operating repeatability at which a vision inspection solution performs. These include:

A vision system is designed to have a level of repeatability appropriate for the task at hand. System repeatability in a given application can be verified by consistently detecting the same defect on the same bottle as it is sent through the system multiple times. A high level of repeatability ensures that the vision solution will consistently find the same defects on products when presented during production runs at production speeds.

Actual product testing is essential in order to determine production line capabilities. Ultimately, in-line factory simulations need to be undertaken to ensure that any inspections quoted are repeatable for the intended application and operating environment.

Measurement repeatability is described by a single number which is the range of repeated measurements of a single part when measured multiple times. This “six-sigma repeatability” should be no greater than a small fraction of the allowable measurement range, or tolerance.

4.1 Factors Affecting Repeatability When comparing the performance of alternative vision inspection solutions, it is important to ensure that the repeatability of each system is measured in the same way.

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Mechanical design Environmental conditions Inspection speed Lighting Product stability

4.2 Mechanical Design As the camera’s lenses, standoff distances and light sources are determined, the mechanical setups can be defined.

When designing the mounts for the cameras and lights the ability to make adjustments is important for installation, operation and maintenance. The devices have to be protected against vibration or shock. In some cases a mechanical isolation might be necessary.

The position of the cameras and lights should be able to be easily adjusted. However after alignment, the devices must be locked down to avoid being moved by operators.

Easy positioning is achieved by a mechanical setup that allows the freedom for the light and cameras to be adjusted independently from each other.

4.3 Environmental Conditions

Vision inspection solutions can be influenced to varying degrees by adverse environmental conditions such as plant vibration, dust, ambient lighting, humidity, and temperature fluctuations. These effects become even more acute when operating at high speeds and the system is performing many inspections at the same time. Unless good design techniques are employed to eliminate the problem, the only solution may be to reduce the speed of the line or number of inspections being performed. For this reason, when comparing solutions capabilities, it is important to take into consideration the experience of the supplier’s equipment in factory conditions.

4.4 Inspection Speed Minimum and maximum inspection speeds are seldom a limiting factor for vision inspection solutions, particularly on conveyor type applications. The limit will vary from manufacturer to manufacturer but will be a function of product handling capabilities and image processing power.

4.5 Lighting Illumination for a vision inspection is critical for an optimum solution. Finding the best setup is a result of experiments based on a theoretical approach. The illumination concept determines the quality of the features to be inspected in the image. These features need to be presented with a maximum contrast. The effort invested in setting up the illumination concept increases the system’s inspection performance and reliability; it will also decrease the complexity of the software. Some of the typical things done are:

Different methods of lighting including diffuse darkfield, on axis, and backlight.

The light spectrum also influences the contrast.

Effects such as fluorescence or infrared or ultraviolet light should be checked. For color applications, the light spectrum needs to be verified for usability; For example, blue light makes yellow dark.

Polarization: the effect of polarization increases the contrast between object areas that directly reflect light in comparison to diffuse reflection.

Polarization will highlight features on metal and glass that would normally be obscured by a reflection.

When inspecting a number of features, different illumination setups might be required. The influences of different lights on the images have to be checked. To avoid interference, a spatial separation can be achieved by using different camera stations downstream. The part is imaged with different cameras and light for a different set of inspections. Another solution is the use of different color light for the cameras to prevent interference. This can be achieved by color lights in combination with color filters for the cameras.

4.6 Product Handling Finally, if the product is not displayed to the camera in a stable, consistent manner, the inspection will be neither reliable nor repeatable. A well-designed vision solution is able to handle a certain amount of variation in the product presentation through its software, and in some cases special optics.

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5: Introduction to How Vision Technology Works

Chapter 5 Introduction to How Vision Technology Works Understanding the fundamentals of how vision inspection systems work is essential to evaluating the contribution it can make to a company’s operation. This section will introduce the variables involved in setting up a vision inspection system. Setting these variables correctly, with the right tolerances, is essential to ensuring an effective reliable system which works in a dynamic production environment. If one of the variables is not correctly adjusted or designed for, the system will continuously cause false rejects and prove to be unreliable.

Vision Inspection involves taking an image of an object, which is to be inspected and converts it into data for the system to process and analyze, ensuring it meets the quality standards of its manufacturer. The ones that don’t meet the quality standards are tracked and rejected.

The number of pixels that the image is represented by is called the resolution. The higher the resolution of an image, the greater the number of pixels it contains. For inspection purposes, the greater the number of pixels in an image, the more accurate the inspection can be. The standard camera image has resolution of 680 x 480 (680 pixels across x 480 down); a higher resolution can have a resolution up to around 2450 by 2050.

The image

Camera

The camera captures an electronic image of the object to be inspected, which is then sent to a processor to be analyzed. The electronic image is converted into numbers representing the smallest possible parts of the image, called pixels.

A vision inspection camera has three variables which need to be adjusted to optimize the image captured. These are the f-stop the contrast and the shutter speed.

5.1 Fundamentals of Vision Inspection Technology

To visualize this, place a piece of graph paper over a photo and color the squares with colors matching the corresponding parts of the photo. Each square represents a pixel.

Above: Illustration of a pixel

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The f-stop, which set on the camera lens, controls the amount of light passing through the lens by adjusting the diaphragm. A high f-stop lets less light in to the camera and a lower setting lets more in. The amount of light will help to create contrast between the inspection and the object. This control needs to be adjusted for optimum result. The f-stop setting also influences the distance to the object required for an optimum image and the type of lens used or depth of field of the lens (the area that will be in focus). The larger the f-stop, the larger the depth of field will be.

Contrast is simply defined as the difference between dark and light areas of an image. The contrast settings in the system primarily affect the ability of the system to define edges. An extreme high setting turns the light areas of the image white and the dark areas black. This results in detail being lost. A low setting turns the image grey, with not enough contrast to clearly define details such as edges.

When contrast has been adjusted properly, there is a balance between light and dark areas.

Back Light: creates contrast by creating dark silhouettes against a bright background. The most common uses are detecting the presence/absence of materials, part placement/orientation and for the precise measurement of objects.

Direct or Bright Field Lighting: The most commonly used lighting technique, is a direct or bright field light. It typically used when generating contrast to enhance topographic detail.

Shutter speed is the amount of time that the camera sensor is exposed to the light that is let in by the lens. Long shutter speeds can result in blurred images, especially on highspeed production lines. Shorter shutter speeds avoid the blurring, but result in darker images. The proper shutter speed will allow for a crisp, well-balanced image.

Dark Field Lighting: a low angle of light incidence and Lighting

typically requires close proximity. Only small amounts of light are reflected back to the camera from edges.

Proper lighting is critical to help create the required contrast to do an effective inspection. When a product is being evaluated for the correct system setup, the designer will spend a considerable amount of time determining the best lighting for the inspection. The type, geometry, color and intensity of the light solution deployed must be designed to provide the greatest possible contrast.

The types of lighting configurations that can be used to create the maximum contrast for the inspection are:

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Cloudy Day or Diffuse Light: Diffuse dome lights are very Vision inspection software tools

5: Introduction to How Vision Technology Works

effective at lighting curved, highly reflective surfaces. To be effective, diffuse lights, need to be located very close to the sample.

Vision inspection systems use software to process the images. The software makes use of algorithms called tools to help analyze the image. The vision inspection solution makes use of from one to a large mix of these tools to complete the required inspection. These vision tools are highly adjustable and allow the user complete control of the placement, functionality and accuracy of the inspection process. When using a complete vision inspection solution, the HMI will provide a user interface screen that contains tool controls (buttons, option lists, text boxes, and control bars). These tool controls enable the user to fine-tune the inspection for each product being inspected.

Though there is a huge range of different tools available for inspections, the following is a list of the typical tools used in a vision inspection solutions.

Search Tools

Diffuse On-Axis Light (DOAL): DOAL, light rays reflect The Search Tool looks at and stores a specific Region of off a beam splitter directly onto the object at nearly 90째.

With this approach, specular surfaces perpendicular to the camera appear bright, while surfaces at an angle to the camera appear dark.

Interest in an image, which it then later looks for during the inspections. When operators train the search tool, they tell it what part of the target image to remember (the model) and where to look for that target during run time (the search area).

The bigger the search area the more processing power the vision inspection solution will need to make the analysis. The smaller the area the less processing power will be required.

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Edge Tools

Process Tools

The Edge Tool looks for the boundary or transition between dark and light. This tools allows for measurement between light and dark areas.

The Process Tool modifies data in a specific region of an image by using various mathematical algorithms to increase the contrast between acceptable and unacceptable quality parameters. The system user designates the area to be “inspected” when training the product into the system.

As demonstrated below the Process Tool can be trained to use many processes to manipulate an image to prepare it for use by another tool. Some of the sub-processes run by the Process tool include:

Sharpening an image (to bring out detail) Edge Detect highlights edges in an image. Can be

used to find less obvious defects.

Smooth an image (to remove detail that is unimportant)

When setting up an edge tool, it must be set up to include both background and the part, in order to find the edge.

But if the edge tool inspection area extends too far into the background, the tool may find another edge before it reaches the desired one. The same will be true if the edge tool area extends too far beyond the desired edge.

Blob Tools Blob tools are used to find features that may be odd-shaped and that may change shape from inspection to inspection.

The blob tool converts the original image it detects into black and white, making all bright pixels white and all other pixels black. This process is called “thresholding.”

A threshold level will be set for the blob tool before it does the inspection.

A blob is a continuous group of pixels.

Right: Process tool applied to create contrast - making swarfs inside a bottle easier to find. Left: image before process tool applied.

Vision Print Tools These tools are used to read, inspect and qualify printed alphanumeric codes, mainly the OCV (Optical Character Recognition), and Bar Code tools.

OCR (Optical Character Recognition) Tool The OCR Tool recognizes printed text and translates the image of the printed text characters into character codes that a computer can understand and use for the required inspection.

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5: Introduction to How Vision Technology Works 20

OCV (Optical Character Verification) Tool

Code Tool

The OCV tool inspects and verifies that the printed characters are correct by matching the characters to known characters stored in a font. The vision inspection system can hold an unlimited number of stored fonts in its font library. Operators can choose which trained font to use during an inspection. If the desired font doesn't exist in the library, a new font family can easily be created and stored.

The Code Tool is used to compare printed bar codes on products to codes that were trained into the system. This tools major function is to act as “decoder� for the system, enabling it to read bar codes and carry out readability and correctness checks.

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Above Left: barcode Above Right: 2D matrix code

Notes

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6: Building Blocks of a Vision Inspection Solution

Chapter 6 Building Blocks of a Vision Inspection Solution There are a number of components available to choose from when specifying a vision inspection solution. These components are the fundamental building blocks of a solution and are critical to the effectiveness of the inspections the final solution performs. If these blocks are not specified correctly from the start, the vision inspection solution will not have the required reliability and repeatability, and the inspections performed will be compromised. This chapter summarizes the 3 types of vision inspection system technologies; sensors, smart cameras, and PC-based solutions, which can be used when designing a solution.

6.1 Vision Inspection Solution Types

There are three different types of vision inspection technologies that can be used when designing a vision inspection solution. These include sensors, smart cameras, and PC-based systems. When deciding which technology to use for a solution the following variables have to be considered

The following are a summary of each of the three technology types and some of the key factors for choosing one or another. At the end of 6.3 there is quick reference summary chart for reference.

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The speed of the line and number of products being inspected.

The requirement to include other components like printers, sensors or reject mechanisms in the same solution.

The complexity of the inspections required, resulting in customized/multiple inspection tools, custom lighting, high resolution cameras and special lenses.

The number of different product sizes, shapes and colors being inspected with the same solution.

Who will operate the machine on a daily basis, and as a result how intuitive the user interface should be and what effort is required for routine tasks such as product changeovers.

Whether the data from the machine is to be used in quality evaluations of the line.

Is integrated parts tracking required?

The requirements to integrate into the production line, in terms of communication with other hardware and the plant management system.

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Security system log in, including log files of the solutions system inspection activities and the user changes to the system.

6.2 PC-Based Vision Systems Vision Control Unit An advantage of using a PC-based technology for your vision inspection system is that the vision control unit can be made integral to the system. A vision control unit for a vision system can perform a variety of functions but is primarily used for product tracking and communicating with other equipment on the line. The software could also be used for product tracking, but the communication with the other hardware in the line is not as simple as a result.

Human Machine Interface (HMI) The PC-based technology also lends itself to having an integral touch-screen HMI, allowing for convenient and immediate interaction between the operator and the vision inspection system. This is something that can be added as an option to the Smart Camera technology, although typically would not be standard.

An intuitive HMI makes adjusting vision analysis tools, changing parts, monitoring of system performance a lot simpler than if a PC needs to connected to the system, as with some of the other technologies.

The advantage of a touch screen HMI is that it does not expose the system to the risk of damage to an external mouse or keyboard from dust, or damage from the environmental conditions in a manufacturing facility.

goal for optics is to use lensing which produces the best and largest usable image, thus providing the best image resolution. The goal for lighting is to illuminate the key features being measured or inspected. Another major goal is to create as much contrast as possible between the acceptable product conditions and the defective conditions.

Often the type of light used will be dictated by things like: color, texture, size, shape, reflectivity, etc.

Lenses

Cameras Camera selection is directly tied to the application requirements and involves three main criteria:

Monochrome or color acquisition Part/object motion Image resolution

Monochrome cameras are used for a majority of inspection applications since monochrome images provide 90% of the available visual data, and are less complicated than their color counterparts. Color cameras are used when inspection applications require color-specific image data to be analyzed. The speed at which the part is being inspected will dictate if a standard interlaced camera can be used or if a progressive-scan camera is required to ensure a sharp image. In addition, the camera’s resolution should be high enough to ensure that it can capture the proper amount of information needed for the inspection task.

Finally, cameras should be high quality and rugged enough to withstand vibration, dirt and heat present in an industrial environment.

In more recent years cameras with faster capacity to transfer data to the processor have become available on the market. These are called GigE cameras and have become the interface of choice for vision systems for a variety of reasons. The GigE vision interface is able to supply streaming, uncompressed image data to a host computer for processing in real time, across long distances, and without limiting the number of cameras being networked together. The evolution of Gigabit Ethernet cameras has also eliminated the need for expensive and complicated frame grabbers to compress and display the image captured by the camera to the image processor.

Optics and lighting

Choosing the correct lens for a vision application is vital to its success. The following describes some of the lenses available and their general usage.

Conventional Lens Fixed focal length lenses are commonly used in vision inspection applications. They provide the resolution, performance, and durability required to produce the needed high contrast and edge sharpness in production environments.

Left: Conventional Lens

Telecentric Lenses Telecentric lenses are ideal for gauging applications due to their ability to provide absolute measurements regardless of whether an object moves closer or farther away from the camera. With conventional lenses, the closer an object is to the camera the larger it will appear, a concept called “perspective distortion” or “perspective error.” Telecentric lenses have no such error or distortion. As a result, objects being inspected do not have to be exactly positioned before being inspected. Although a more expensive option, it might be more cost-effective than implementing a handling solution to accomplish the same thing.

Left: Telecentric Lenses

These crucial considerations are often the most overlooked.

When poor optics or lighting are used, even the best vision inspection solution will not perform as well as a less capable system with good optics and adequate lighting. The typical 2010 Mettler-Toledo CI-Vision

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6: Building Blocks of a Vision Inspection Solution

Specialty Lenses Fish eye lenses can be used in applications where a large area of an object must be inspected but where very little space is available. With a field of view of more than 185º, they are not used as often as conventional lenses but can be ideal for certain inspections. An experienced vision inspection solution provider will know which lenses to use in each circumstance.

6.4 Sensors Right: Fisheye Lens

6.3 Smart Cameras The second vision inspection technology to be considered when evaluating a solution is Smart Cameras. They are equipped with image-processing capabilities integrated into the camera. This makes them small, compact and a simple solution for some simple vision inspection applications.

Smart cameras don’t have the same amount of processing power as the PC-based technology, and as a result suffer from some performance restrictions when trying to operate at medium to high speeds, when performing more than one inspection or when trying to use multiple analysis tools at the same time.

Vision Sensors The final vision inspection technology to consider are vision sensors. These are the simplest of technologies with a very large range of options. Vision sensors provide the end user with a cost-effective inspection technique that requires minimal effort to integrate. Depending on the level of precision required, vision sensors can be appropriate for many basic inspections such as level measurement, bar code reading, color verification and presence/absence detection applications.

Typically the sensors have simple optics and limited lighting, and as a result usually require a sharp contrast between the feature being inspected and the background behind it, to ensure accuracy. For example, if a sensor is installed to verify a bar code on a dark red label and the code is printed in light red, the sensor would struggle, there would not be enough contrast. Although if the bar code was white and black, there would be sufficient contrast and the sensor would work.

Right: Vision Sensor

Typically, the smart cameras come embedded with a set of predetermined analysis tools. These tools are selected based on the inspection requirements of the given application.

A smart camera can be an effective solution for singlestation vision applications that require more precision and flexibility than a vision sensor can provide.

It should be noted, however, that there are some limitations to the smart camera, including:

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measurements between multiple cameras without implementing specialized software.

Part changeover can be made difficult if an integral HMI is not included, because an additional PC will need to be connected to make changes.

Sometimes lighting comes as part of a smart camera, but if this does not suit the application it is difficult to adjust or change to improve the inspection.

Difficulty when trying to link multiple pieces of hardware in a production line.

Statistical feedback to plant management systems or the quality manager of the typical failures.

Limited when an inspection is required to correlate data between multiple cameras, such as dimensional

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Another point of caution around the sensor technology is that they rarely can be used together for an inspection, unless a PC is used to support, and then a PC-based inspection technology would be worth considering from the start.

The following section provides a brief overview of some of the types of vision sensors commonly used in the packaging industry.

Contrast Sensors

Color Sensors

A contrast sensor can be ideal for presence/absence inspections such as checking that a label or cap has been applied to a product. As mentioned above there would need to be a significant contrast between the label itself and the product to which it is applied.

Color sensors are used to inspect differences in color. They use a color match tool and compare the color of the product being inspected to a known reference color it is programmed to find. Color sensors can also be used to detect subtle color variations, allowing the user to set threshold values to identify products outside the threshold colors

Luminescent Sensors Luminescent sensors are especially appropriate for applications in which companies are inspecting for adhesive presence on an area where a seal is going to be applied. Oftentimes the adhesive may be clear, so it will not be visible to the sensor unless it is illuminated with ultraviolet (UV) light. A luminescent sensor embedded with a UV light source will be able to detect the presence or absence of the adhesive before the sealing process, to ensure that the seal is applied properly.

Left: Luminescent Sensor

Left: Color Sensor

Barcode Sensors Barcode sensors are relatively simple devices, and can be extremely valuable on a production line. Beverage companies, for example, use barcode scanners to determine that the proper cans or bottle labels have been mounted into a high-speed filling line, ensuring that the correct container is being filled. This can help avoid extremely costly mistakes for high speed bottlers.

Sensors

Smart cameras

PC-Based System

Speed

Fast at simple inspections

Determined in case by case basis

Fast at both simple and complex inspections

Capacity to add additional components for inspections (Expandability)

No

No Capacity

Can integrate with multiple types of hardware

Multiple inspection tools

No

Limited

Can apply unlimited tools to provide optimal inspection

Optimized lighting

N/A

Limits the range of inspections

Lighting solution developed for specific inspections

Optimized cameras

N/A

Limits the range of inspections

Camera solutions developed for specifc inspections

HMI

Need to use external device

Additional integration necessary

Consistent HMI integrated in systems

Ability to change parts through HMI

With an additional device

With an additional device

Consistant HMI across all inspections

Statistical analysis package

N/A

No

Readily available

Integrated parts tracking

N/A

N/A

Time or encoder-based tracking standard in most systems

Communication with other line equipment

Simple communication

Simple communication

Complex correlations with other line equipment i.e. feedback to filler, labeler, conveyor stoppage, etc.

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6: Building Blocks of a Vision Inspection Solution

Since these lines fill at very high rates, often more than 2,000 bottles per minute, an error discovered too late can result in thousands of containers being recycled and high volumes of product being discarded.

Sensors have the ability to read data matrix, code 128, EAN/UPC and Pharma code barcodes and some also have barcode grading capabilities.

One limitation of barcode scanners is that they are often times not capable of matching the barcode data they detect to other printed codes on labels or packages, such as date/ lot codes, reducing their flexibility.

6.5 Vision Building Blocks Applicable to all Technology The following building blocks of a vision inspection solution are applicable to all three types of technology.

When specifying a vision inspection solution, these are often forgotten or not specified, although can be critical to making sure your system works effectively.

The vision system’s enclosure must be designed to isolate the inspection process from outside factors in the production environment. Some of those factors include ambient light, electrical noise, and operator interference.

At the same time, it must be durable and constructed in a manner consistent with the operation it is integrated with.

Whether it is installed in a pharmaceutical clean room or food-grade wash-down environment, the vision system must meet the standards of the environment.

Product Handling and tracking

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The product needs to be displayed at a consistent distance from both the camera and the light. If not the cameras might not be in focus and the lights might not provide enough intensity The product must be presented with minimized movement. The more vibration and instability in the product the lower quality the inspection will be The product needs to be presented with correct spacing, if the products are too close the cameras won't be able to inspect the correct part of the product The product needs to be correctly oriented. There are vision inspection solutions which can inspect 360 degrees around the product.

Once the inspection has been performed, the defective product needs to be tracked and rejected. The aspects of this part of the product handling are

Vision System Enclosure

If the product being inspected is not presented to the vision inspection solution correctly, the inspection will be compromised (for a detailed overview of the options available for product handing please see chapter 7). Main things that need to be considered when specifying the product handling for a vision system are:

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An encoder used to track the position of a conveyor or rotary dial regardless of speed or changes in speed. This is useful when a product is moved on a conveyor and does not slip on the conveyor, as it can then be tracked regardless of normal fluctuations in convey speed.

Product rejecters to take defective product off the line.

Reject confirmation sensor is often used, ensuring that the product has gone into the reject bin.

Lockable reject bin, to avoid the product from being put back onto the line, and to make sure it is available for the quality inspectors to review the defect.

Features of a Vision Inspection Solution

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7: Importance of Product Handling

Chapter 7 Importance of Product Handling Once the type of vision inspection technology is chosen, whether a sensor, smart camera or PC-based system, it is then important to look at the product handling required to ensure the products are displayed to the cameras correctly. As stated in Section 4.4 product handling is critical to ensure a good, reliable, repeatable inspections. To do this: • The product must be displayed at a consistent distance from both the camera and the light. If not, the cameras might not be in focus and the lights might not provide enough intensity • The product can not be presented with minimized movement. The more vibration and instability in the product the lower quality the inspection will be • The product must be properly spaced. If the products are too close together the cameras won't be able to inspect the correct part of the product • The product must be properly orientated. There are vision inspection solutions which can inspect 360 degrees around the product, but if the product can be orientated and be displayed to the cameras in a consistent way, this reduces the necessity of such a complicated solution The following section outlines the options to make sure that these things are considered when specifying the system. Time spent correctly specifying the correct product handling mechanisms will be rewarded by a high quality, effective reliable vision inspection solution.

This section provides practical guidance on equipment selection and explains how the adoption of best practice techniques and incorporation of fail safe features can further improve the overall accuracy of product inspection.

Product Handling includes the types of equipment used for products to travel through production, i.e., conveyors (some applications require conveyors to be integrated with the vision inspection solution in order to present the part to the camera for inspection), product spacing, mechanisms to reject the defective product and confirm that it has been rejected.

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7.1 Conveyor Flat Grip Conveyors Flat belt conveyors are often included when parts must be stabilized for inspection. Chain link production conveyors may vibrate or shake, making accurate measurements difficult. Flat belt conveyors with vacuums increase the level of product stability even further.

Side Grip Conveyors

7.2 Other Spacing Solutions

Side grip conveyors are generally used when the bottom of a product needs to be inspected. An example would be inspecting the bottom of a jar for debris or codes. The jar must be picked up off of the existing production conveyor, illuminated, and presented to the camera for inspection.

In instances such as this, the vision system should come equipped with a side grip conveyor.

It may not be possible to use conveyors to space difficult to handle products. This is mainly due to stability challenges caused by a sudden acceleration or deceleration of the products. While there are numerous spacing solutions two of the most common alternatives include a timing screw and star wheel and sidegrip conveyor.

Timing screw is used to space product evenly through vision inspection solution.

Above: Side Grip Conveyor

Package Spacing with Conveyors In order to inspect products accurately, it is essential that only one item at a time be in line with the camera. If there is not enough spacing between items, errors will occur. For example, if inspecting bottles and there is not the proper amount of spacing between each item, additional bottles may end up in the camera field of view, impeding the ability to inspect the current bottle of interest. In order to create or maintain an appropriate spacing or pitch, spacing belts speed up products and create a larger gap between items.

In this case the spacing conveyor will run at a faster speed than the production line.

Starwheel used to space as well.

7.3 Automatic Reject System Automatic Rejection Systems are used to remove imperfect/ defective products off of the production line. The most appropriate choice of reject system will depend on a number of factors and the advice should be sought from the manufacturer of the solution. Some of the most common types as follows: Air Blast

Above: Example of Bottle Spacing

If items are randomly approaching the vision machine without any consistent spacing, it may be necessary to time packages. A timing conveyor creates a uniform spacing between items.

A blast of air blows the product into the reject location. This type of reject is ideal for light, single file discrete products running on a narrow belt width. It is recommended that a “gated timer� is used in conjunction with the air blast to ensure the air blast is directed at the center of the product regardless of the location of the contamination.

Typically the timing conveyor will slow the packages to create end-to-end spacing (where the pitch equals the length of the item). Timing prepares items for the spacing conveyor.

Above: Air Blast

Blow rejecter is used for lighter products.

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7: Importance of Product Handling

Punch / Pusher

Drop Gate Rejector

This device operates at high speed to push individual product into the reject location. High belt speeds are acceptable but on closely spaced items recovery time must be extremely short. This type of reject is suited to light to medium weight discrete packs, spaced and oriented on a narrow belt width.

This type of reject must always be “gated� to ensure that the punch always strikes the center of the product, regardless of the location of the contaminant. It is unsuitable for loose or fragile products.

Drop gate rejectors are conveyors which mechanically slant downwards to reject items. They are useful for items which are difficult to direct away from the direction of travel.

There are limitations on item height and throughput for drop gate conveyors.

OK

Outfeed Reject

Line Control Above: Punch/Pusher

Soft Finger Rejector A series of fingers (generally between 8-16) are used to reject fragile containers that need to continue to stand upright after being removed from the line.

Above: Soft Finger Rejector

Center Gate Rejector Gates can divert and guide products between multiple lanes.

Gates can be used as a soft rejector or a classifying tool.

Center gates pivot on a vertical plane and direct items left or right.

Center Gate Diverter OK Reject Travel

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Travel

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Vision system line control capabilities include stopping and starting of the production conveyor at any customer defined preference. For example, it can be used for one single defective product, a series of defects, or a certain percentage threshold.

7.4 Reject Timing It is normal for some time lag to be required from the moment the defect is identified to the moment of rejection to allow the product inspection to move to the reject point.

This can range from fractions of a second on high-speed applications, where the detector and reject device are close together, to as much as 30 seconds when rejection is planned at some remote point, either manually or automatically.

A second independent timer is also required which will control the length of time the reject device operates for.

This is usually adjustable from approximately 0.5 seconds to 10 seconds. The shortest time would be required on a punch type reject; a retracting band system would normally operate for several seconds to remove larger items from a slow moving belt. Both timers would normally be available as standard feature to be part of the total vision inspection solution.

It is important that the timers are immediately re-settable and that the vision inspection solution is still operative while timing out. The solution must be capable of detecting a second defective in a following pack and resetting or extending the time to ensure this second pack is also rejected. A continuous stream of failures should result in the reject device operating continuously until all the defective products are identified.

In-feed conveyor product handling One of the differences of vision inspection solutions to other forms of product inspection is that a solution does not necessarily have to break into the manufacturer's production line to install the solution. Frequently vision inspection solutions are designed to fit over the top of existing production lines. This means that no in-feed conveyor is required, as long as the product meets the presentation rules stated at the start of this chapter. If this is not the case in-feed conveyor solutions will need to be considered.

If this is the case product transfer solutions need to be considered. Poor transfers on and off the vision inspection conveyor can cause product jams and vision inspection solution imaging issues. Special attention needs to be given when the end rollers are large or the product is small (Figure 7.1). If the distance D between rollers is more than half the product length, reliable transfer will not be possible. Small non-powered intermediate rollers, or a dead plate positioned between the two rollers, are an effective solution with some products.

are used for in-line transfers, packs will fall over or lose pitching. A common method of transfer for these containers is a side-by-side transfer from the main conveyor line and back again. This is a basic concept for side transfer.

Variable Speed/Stop-Start Applications Accurate rejection and timing become more complex if the transport conveyor has variable speed or can be stopped with product between the camera and the reject system. The time taken for the product to move to the reject position is not constant and so a simple time delay method cannot be used.

The normal solution is to use an encoder which can monitor belt movement and the position of product on the belt. A shift register is a device which will give an output signal after it has received a predetermined number of input pulses. It is of no importance if these pulses are received rapidly or over a long period.

The input pulses are produced by a pulse generator fitted to the shaft of a roller on the conveyor system. It is normally made form a metal disc with teeth or holes cut into it.

Each time a tooth on the disc obscures the photoelectric device or passes close to the proximity sensor, a pulse is generated.

First In First Out (FIFO) The timing of the rejecter is important to make sure it rejects the correct product and does not interfere with the neighboring packs and causing a line blockage. If using air blast or punch/pusher rejection, a possible solution would be to adjust the timers to operate early and for an extended period. This, however, would remove several good packs and most likely spin or disturb others. The best, and only solution when punch rejects are used, is to accurately monitor the position of the pack and operate the reject device when it has reached the correct position. The technique is known as “photo-gating.� This will ensure accurate rejection.

7.5 Typical Reject Problems and Failsafe Design

Figure: 7.1

Single or double knife edges (Figure 7.1) permit transfer of very small packs, where product reregistration needs to be maintained, such as rows of confectionery at the outlet of an enrober.

For jar and bottle inspection, an in-line transfer can be difficult as the packs are unstable and tend not to selftransfer across dead plates. Unless special handling devices

Ineffective reject systems are probably the weakest link in most product inspection machines and result in product not being effectively and reliably rejected from the line.

A correctly specified system should be foolproof and capable of rejecting all defective products under all circumstances.

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7: Importance of Product Handling

The following are common application problems which should be taken into consideration when specifying a vision inspection system:

7.7 Reject Receptacles Tray, Hood, and Bin, are the simplest and most economical forms of reject receptacle, mounted on the vision inspection solution at the point of rejection.

Tray

One of the benefits of a single source responsibility for conveyor, reject, product handling and product inspection is that these issues can be addressed at the design stage, where necessary.

A tray is a simple three-sided holding table with no cover, where rejected packs enter and are contained.

7.6 Satisfying Retailer and Food Industry Requirements

A hood is a box-shaped structure with openings on one side and in the base. The reject pack enters through the side opening before dropping down and out through the base.

The hood funnels rejects down to a rework area or into a receptacle, e.g. a stainless steel tote bins.

Simple additional control devices can be included in the Product Inspection system design that will ensure a reject device is operating properly, that failure issues are accurately rejected, and the Product Inspection system is operating in a failsafe mode. Implementation of the following design requirements generally represents good practice and will probably satisfy most brand retailer and food industry requirements:

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Reject not suitable for the application.

System not capable of removing consecutive defective products. When a number of consecutive defective products occurs, the reject device must be capable of accurately rejecting each one, without a line blockage.

Failure of the reject due to low air pressure, blockage or solenoid failure.

Conveyor speed changed without due consideration to changing reject timings.

Product spacing and reject design not compatible

It should only be possible to restart the system via a security password or a key held by a nominated person. Suitable arrangements and procedures should be in place to ensure that any products “backed-up” on the in-feed conveyors to the Product Inspection system belt, during a period of time when the Inspection System belt itself is stopped, are passed through a working detector to the same sensitivity.

An automatic reject system to effectively remove product from the production line.

A warning device to indicate when the bin is full of product.

A full enclosure between the detector head and rejection bin.

An audible and visual indication of system status, e.g., product has been rejected.

A photocell to detect each pack passing through the system (to facilitate the correct timing of the reject mechanism).

An automatic belt stop failsafe system in response to the following events: -- Reject bin full -- Loss in air pressure -- Reject confirmation system fault -- Detector fault

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Hood

Bin A bin is a box-shaped structure. It has an opening on one side to admit rejected products, and a side access door near the base for removal of rejected products. Good practice is to have drainage holes in the base for good cleanliness. It is recommended to have the door lockable, so that only designated personnel can remove rejected packs.

Chute A chute is a long narrow horizontal bin, usually angled downwards away from the solution. Instead of rejected packs dropping (maybe 500mm) into the base of a bin (with the risk of damage), the packs slide down to the bottom of the chute. A chute is typically used for fragile containers or ones that require detailed inspection.

Declined Roller-Track Reject Conveyor

Reject confirmation

A declined roller-track reject conveyor is a reject chute with rollers in the base. Reject packs are easily and smoothly transferred via the rollers to the bottom of the receptacle.

Since no damage is caused to the product on rejection, this is ideal for use on re-workable high value products. It's also good for products that may have a missing or damaged component. These packs can be fixed or components replaced and re-inspected. Again drainage slots in the base, a viewing panel and a lockable access hatch are good design practice.

It is also good design practice to include a reject confirmation into the reject system. This is a powerful tool to support quality programs with data about the products which are being detected and rejected. This can help to help give confidence when trouble shooting the source of defective product. Those caused in the production line will be identified and confirmed to be rejected. The other defective product would be coming from other places, like the forward supply chain or the point of distribution.

The reject confirmation can also help to prove due diligence in claim cases or if defective product is found by retailers or consumers.

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8: Complete Vision Inspection Solutions

Chapter 8 Complete Vision Inspection Solutions A Vision inspection solution's value is not a result of the sum of its components. There is a significant amount of engineering, product testing, design and know-how that goes into a system to ensure that it: • Inspects reliably and accurately every day in real-life production environments • Offers operators a simple, intuitive user interface • Can be easily and quickly adapted to inspect a range of products shapes, colors, and sizes • Is simple to install, calibrate, and maintain with expansion capabilities This section of the Vision Guide discusses the factors that make up a total vision inspection solution and outlines the value that it can bring to the user and the manufacturing facility that takes advantage of them.

Inspects Reliably and Accurately Every Day in Real-Life Production Environments Vision systems have been used in manufacturing for more than 20 years in a large range of applications. Some of these systems have delivered the expected results, although many of them have failed to deliver the reliability and repeatability of the inspection required. The main reason for this failure is the level of accuracy that is specified in these systems. When specifying a vision inspection solution, there is a large range of variables that influence the quality of the final system. Some of these key variables are:

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The type of ambient lighting in the manufacturing facility and how it could effect the inspection if not controlled.

The resolution of the cameras.

Consideration of environmental factors such as vibration, temperature and humidity.

The reflective properties of the material being inspected.

The contrast between the inspected variable and the surroundings.

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The movement of the product.

The speed of the line.

The frequency of product changeover.

Product handling requirements.

Above: An example of a complete vision inspection solution.

If some of these variables are specified too tightly or others not tightly enough, the system will fail to operate effectively in the day-to-day manufacturing environment.

As it turns out, the success of any vision system implementation can be hindered by many factors.

It is only through experience that these factors will be properly considered. Make sure that the experience of your supplier matches the complexity of your inspection and the environmental factors of your factory floor.

As a result, it is recommended to select a vision system supplier who is able to translate these influencing factors into a vision lab analysis and produce a product specification which can not only work during the factory acceptance testing, but also day in, day out and year in, year out on the manufacturing floor.

Once the vision inspection solution has been developed in a robust lab environment, a detailed product-testing program can be developed to ensure that the equipment is rigorously tested during ongoing operation.

The vision solution supplier is also able to take the product specification and reflect that in the type of mechanical design of the inspection system. Some of the things which need to be considered are:

Matching the reject mechanisms to the product being rejected.

Designing the product handling to ensure consistent product presentation that the inspection is done accurately each time.

Designing the frame to suit the plant’s hygienic requirements and fit into the space available, with minimum impact on the line operation.

Requiring safety features and interlocks necessary to keep the operators safe.

Offers operators a simple intuitive user interface An effective Human Machine Interface (HMI) is critical to the functionality of any machine in a manufacturing facility. Without a well-designed, intuitive HMI, the use, operator acceptance and efficiency of the machine will be compromised. A vision inspection system HMI that has been rigorously tested, developed and proven over time will allow the operators to efficiently changeover products and monitor the performance of the production line without significant effort and stress, allowing them to concentrate on the core processes.

In larger factories, where there are multiple vision inspection solutions, having a consistent HMI across all systems can also make a difference to operator's competence and efficiency of all the vision solutions. This can also speed up product changeover.

Even with a well-thought-out and intuitive HMI, operator training is important to prove to auditors and management that the production line is being run correctly, and to make sure the equipment is being used to its full capacity.

Can be easily and quickly changed to inspect a range of product sizes, shapes, and colors The pressure to keep up with ever-changing consumer tastes and styles means that product packaging shapes, colors, and sizes are changing at a rapid pace. The equipment in a manufacturing facility must be capable of keeping up with this rate of change. These changes impact the following inspection variables for the vision system:

Inspection contrasts Product handling requirements New inspections Potentially different lighting and other camera requirements

The well-designed vision inspection solution can be adjusted and modified not only from a software standpoint but also mechanically, to have the cameras, lights and the inspection geometry changed without having to install new equipment.

In some cases, changes of product will also require a re-evaluation of the inspection parameters, for color, lighting, and cameras used. To support this, a vision inspection solution supplier can take these inspections and develop a new product specification to meet the new requirements. A vision inspection solution should be designed in a way to allow for these modifications while at the same time minimizing the impact on the hardware.

Security Another feature required to help reduce the risk the system being modified or changed inadvertently, is an access password system, where the administrator, engineers and operators are given different access rights, ensuring critical variables are only changed by correctly-trained personal.

In addition, all changes are stored in a file to determine when and who made the changes.

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8: Complete Vision Inspection Solutions

Documentation The supplier of a full vision inspection solution will deliver the solution with a full set of documentation, which ensures that the system is being used correctly and the set-up variables are correct. Proper documentation will also help establish the correct testing programs for the equipment. Some of the documentation required to support this includes:

Product operation manuals Product specifications Installation certificate Product testing instructions Customized manuals Ongoing performance verification certificate System validation

This documentation can also help to prove due diligence in the case of a claim or recall situation.

Interface with Other Systems A well-designed vision inspection solution will also be capable of interfacing with other parts of the company’s operations. Some of the key ways include:

The line can be stopped in the case of the vision system finding a failure of a critical parameter.

This will ensure that the problem is corrected and will minimize the amount of defective product produced.

The system can interface with the plant management system, to monitor and track trends.

Key parameters can be checked to make sure they stay within required parameters, and warnings can be set.

Simple to install, calibrate, and maintain The vision inspection solution must also come with a full service and support program, to allow the purchasers to focus on the production operation. This support will ensure that the system is:

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Installed correctly in your production environment.

Calibrated upon installation, and at regular intervals thereafter, to ensure correct functionality.

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Notes

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9: Typical Vision Inspections for Packaging

Chapter 9 Typical Vision Inspections for Packaging The goal for every automated production line is zero defects. This is a target which, with today’s high-speed technology and the potential for the introduction of human errors, is very difficult to achieve. One goal that is achievable is zero defective products being delivered to the customer, by making use of a range of product inspection technologies.

The following chapter outlines the typical defects which a vision inspection solution is able to identify. The defects are categorized as follows: • • • • •

Label defects Closure and cap defects Product and package integrity defects Print defects Container defects

Today's automated production lines operate with incredible speed and precision. Yet many companies expect that human inspectors will be able to successfully inspect containers being filled, decorated and coded at speeds of hundreds per minute. Automated production needs to be inspected by vision inspection systems that can ensure that 100% of output receives 100% verification before leaving the building.

Example: A label is applied incorrectly, as a result of a bottle not drying fully after washing. The impact of this misapplied label can

Lead to lowering of brand image in the market.

Obscure a listed allergen.

Cause the retailer to dsend the batch back and fine the manufacturer.

9.1 Typical Defects Addressed by Vision Inspection Solutions Typical defects that occur on high-speed packaging lines involve labels, the printing of codes and identifiers, closures, containers and the overall integrity of the package. These defects can lead to product leakage, line jams, damage to other line equipment, damage to the reputation of the company's brand image or cause liability problems if they are allowed to leave the facility and enter the marketplace.

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Above: Example of a label that was applied incorrectly.

9.2 Inspecting for Package and Product Integrity Defects Package and Product integrity refers to the completeness, and integrity of the package or finished product. The following examples are focused on filled bottles, cases, cartons, pouches, packets, kits and cartons.

Defect

Defect Description

Defect

Defect Description

Full Bottle Inspection

Correct Cap Placement Inspection

Proper fill level; Cap presence, height, color & skew; Label presence, position and identification.

Cap inspections: presence, height, skew, color, safety band integrity.

Case Pack Inspection

Anti-Counterfiet and Tamper Proof Band

Internal inspections: Product presence, placement, orientation, count and cap correctness.

Presence and integrity of safety tamper -evident band.

External case inspections: case decoration, ID, and flap position; printed product code and date/lot code.

Blister Pack Inspection

Foil Seal Integrity Inspection

Blister inspections: product presence/ absence, shape, color, and completeness; check for foreign materials.

Inspects both plastic and foil seals for: creases, dimples, punctures, splicing errors, leaks, and thumb tab presence/ absence

Card inspections – date/lot/product code verification.

Product or Kit Content Verification Inspection

Product or Kit Content Verification Inspection continued...

Verify all components of kits or pouches are present, oriented and positioned correctly.

Top Left - Vitamin packet confirmation

Top Left – Packet content inspection Bottom Left – Verifying contents of pouch Bottom Left– Jar content verification

Product Shape Inspection

Slat Filler Confirmation

Verify that the shape and size of a product falls within production tolerances.

Confirms that pills are present, whole and undamaged prior to packaging.

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9: Typical Vision Inspections for Packaging

Defect

Defect Description

Defect Description

Assembly Verification

Cracker Inspection

Verifies presence, placement, color and completeness of nozzle, shroud, trigger and cap.

Verifies that the proper number of crackers are present, in the correct position and whole.

On PET bottles, can also verify fill level and fill tube presence.

Tray Integrity

Confirms that all intended pieces are present and in the proper place.

Ensures proper placement of product in food trays and clear sealing surface.

9.3 Inspecting for Closure and Cap Defects Vision inspection systems are used to detect errors in molded plastic closures and caps, and are typically positioned immediately after the molding machine, and then again just before they are applied to a filled bottle. Defects iand caps and closures can cause damage to other machinery, lead to spillage, spoilage and contamination.

Defect

Defect Description Closure Liner Presence / Absence Verification

Defect Description Liner or Closure Short Shot Check that during the molding process that the shot was sufficient to form the liner and closer correctly

Liner contamination

Liner Placement Verification

Detects loose particles including dust, dirt, plastic fragments and carbon in the closure itself or material embedded inside the liner during formation.

Confirms that the liner is properly placed inside the closure.

Closure Ovality Verification

Closure Liner and Flash Detection

Verify that the closure was formed into the proper ovality or roundness.

Detects if extra product was left on the closure or the liner during the molding process.

Closure Tab Inspection

Component Verification

Detect and inspect the presence/ absence, shape, color and location of the tabs.

Verifies the presence, position, color and orientation of the parts of the closure or cap assembly.

Ensure any product ID codes are present, correct and readable.

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Defect

Verify that closure’s liner is present.

Product ID Verification

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Defect

9.4 Inspecting for Container Defects The types of empty container defects included in this section are typical for bottles, tubes, cans, tubs, and glass bottles and jars.

Defect

Defect Description

Defect

Defect Description

Neck Measurements (E, H & T)

Sealing Surface Inspections

Inspects the width (E - edge to edge), height (H) and thread width (T) of the bottle neck.

Detects nicks, gouges, contamination and deformities on or in the sealing surface.

Planarity Inspection

Ovality Check

Planarity of container top is checked for hairs, filaments and / or waviness caused by uneven cuts during the trimming process.

Verifies that the neck of an empty container is round, dent free and the mouth is oriented in the proper position

Sidewall Thickness Verification

Contamination Inspections

Verifies proper wall thickness by monitoring the rate of thermal change across the sidewalls of the container.

Detect any defects on the sidewalls of the container including dirt, burns, discoloration and embedded or surface particulate matter caused by carbon buildup in the molding process.

Surface Finish Defect Inspection

Blisters and Bubble Inspections

Inspect the container for swirls, scratches and other blemishes in the color or finish of the container.

Verifies the sidewalls and bottom of the container is free from blisters and bubbles in the material.

Foreign Debris Inspections

Chipped Top Inspection

Inspects for chips, swarfs, or any other materials that have fallen into the container during the manufacturing or shipping process.

Verifies that the top of a glass container is free of voids, chips, missing glass and cracks.

Cork presence can also be determined.

Left top: Swarf inside container.

Left top: Top view of a chipped wine bottle lip.

Left bottom: plastic chip in spice jar.

Left Bottom: Side view of cracked vial.

Gate Inspections

Preform Gate Inspections

Inspect for pulled, blown out, burnt, mushroomed, or mis-positioned gate.

Verify preform’s gate has been properly formed.

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9: Typical Vision Inspections for Packaging

9.5 Inspecting for Label Defects High-speed labeling of packages, ranging from boxes, glass and plastic bottles to steel and aluminum cans, can produce a wide variety of defects,which can lead to label errors that can be harmful to a brand or can even present liability issues for a brand owner.

This section covers the potential defects which can occur during labeling of the front, back and necks of products.

Label Presentation Inspections Defect

Defect Description

Skewed Label Detection

Inspects for absence/presence of label on package or container.

Ensures that labels are applied straight and in the correct position.

Dog Ear Label Detection

Double Label Inspection

Verifies that labels have been securely applied to the container or package.

Ensures that only one label has been applied to the same location on the package.

Overwrap Alignment Inspection

Graphical Label Verification

Ensures that wrap-around labels are place properly and put on straight; 360 ddegree inspection can be used for this inspection.

Inspects for unique graphical item on the label to confirm that proper label is being applied.

Label Control Number (LCN) Verification

2D Data Matrix Code Verification

Verifies the correct label control number is present on the label.

Confirms that proper label has been applied by verifying that the correct barcode is present, or that the code has been printed correctly.

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Defect Description

Label Presence Verification

Barcode Verification

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Defect

Confirms that proper label has been applied by verifying 2D data matrix code is prresent, or that the code has been printed correctly.

9.6 Inspecting for Printed Code Defects Labels and packaging are printed with a wide range of different print methods including Ink Jet, Hot Stamp, Laser, Silk Screened/In-Mold, Thermal, Ultra Violet and Embossing. A variety of problems can occur during the print process. Vision inspection technology can easily inspect and verify the quality of the print prior to distribution, independent of the type of printing process used.

Defect

Defect Description

Defect

Defect Description

Barcode Validation

2D Data Matrix Verification

Verifies that the barcodes are properly formed and readable.

Ensures that non-human readable code is well formed, readable and correct.

Lot/Product/Expiry Code Verification (OCV)

Label Control Number (LCN) Verification

Confirms that product codes are present, readable and correct.

Verifies the correct label has been applied to package by verifying proper label control number is present on the label.

Bright Stock ID Verification

UV Print Verification

Verifies that the proper filled and unlabeled cans have been pulled from stock after labels are applied.

Confirm proper UV printed codes are present and correct

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9: Typical Vision Inspections for Packaging

9.7 Bringing it All Together

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The first part of this chapter was dedicated to showing the wide breadth of vision inspections that can be applied to packaging and products. What isn’t apparent is how these inspections combine together to create a total vision inspection program.

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To demonstrate how various vision technologies and inspections work together to form a total quality assurance program, we have included the packaging line diagrams on the following pages. At each quality checkpoint that requires vision inspection, we have included a listing of the inspections that occur there and the best vision technology choice to fulfill the inspection need. At some inspection points, more than one technology is presented. The choice of vision equipment at these points depends on what level of inspection complexity is required.

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10: Building an Effective Vision Inspection Program

Chapter 10 Building an Effective Vision Inspection Program A vision inspection solution integrated into an overall quality program offers a brand owner substantial benefits, including: • Reduce the cost of production and the number of defective products leaving manufacturing • Protect the consumer and brand equity • Increase compliance to retailer and industry quality and safety standards Persistent defects and mistakes are typically caused by improperly-set controls, inefficient operator working methods, flaws in system specifications or system design.

Guide rails, bottle spacers, or star wheels that position a bottle precisely relative to the labeler head, for example, can make the difference between consistently perfect labeling and faulty occurrence of flagged, doubled or missing labels. Similarly, if bottles are not completely dried before labeling, a high incidence of wrinkled labels will result.

Product positioning is also critical for the stationary camera to stay in focus when reading lot numbers and barcodes. A high number of cocked caps may indicate a misalignment of bottles, the capper, or perhaps a problem with the capper feed. All of these defects will be identified and rejected, at a loss of time, labor and product. A well-designed vision inspection program will help identify and minimize such problems.

A well-designed program will also provide data for the quality control team to help further troubleshooting and defect source identification.

Reject the product before it causes damage or leaks on downstream equipment, or reaches the consumer.

Stop the line entirely if a defect continues to occur. (for example an operator loading the incorrect labels for a certain product).

Taking full advantage of the communication capability of a solution greatly increases the benefits that a vision inspection solution has to offer.

Increasing Productivity by Reducing Defects and Mistakes One of the roles of a vision inspection program is to efficiently and cost-effectively detect defective product on the production line. Once detected, the program should allow

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The vision inspection solution to pass data upstream to other machine controls to help prevent this defect from continuing.

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An effective vision inspection program collects and uses run-time data.

Protecting the consumer and brand equity Manufacturers and their employees have an obligation to the consumer and retailers who purchase their products to minimize product defects, ensuring consistent quality and the safety of the consumer.

Failure to do this can damage relationships between the retailer and the consumer and the manufacturer and its customer, resulting in damage to the brand and the loss of future business,

If the lab evaluation is done correctly, the final vision inspection program will have the required tolerances to ensure that the final solution is robust, repeatable and reliable.

During the evaluation the variables to be considered include:

Increase compliance to retailer and industry quality and safety standards Where there is a risk of label mixup or allergen misidentification, vision inspection solutions are often installed as CCPs (Critical Control Point) to support a HACCP (Hazard Analysis Critical Control Point) program.

When this is the case the solution needs to be managed as any other CCP in the production process.

When the vision inspection solution is installed to improve quality, there is no definitive standards legislation, although many large retailers have established standards and codes of practice to which manufacturers are expected to adhere.

Many of these retailer standards, such as label placement and location, are beginning to play a part in supplier selection and the specification of vision inspection standards for manufacturers. In addition, hardware retailers are insisting that full supporting documentation is in place to ensure the correct program controls are practiced. These retailers commonly conduct audits to check that the programs are working effectively so that the quality product they require is delivered. The same documentation can be used by a manufacturer's internal management systems to support their quality programs.

10.1 Using a lab to Evaluate the Right Vision Inspection Solutions To develop a vision inspection program, the manufacturer must have a documented specification in place, which all testing, auditing and training activity can be completed against. To do this, the solution provider should perform extensive testing and evaluating to define the settings and components necessary to optimize the vision system performance, including;

Determining field of view Choosing a lens Selecting lighting

Product size and shape – This will determine the resolution and number of cameras needed to inspect the product.

Defect or inspection area size – Relative to the product size, the inspection area must be defined in order to determine the resolution of the camera.

If there is a small barcode on a large label, a higher resolution camera may be needed to verify the barcode and inspect the label positioning with the same camera.

Product material – This will help determine the lighting technique needed to develop the best contrast for the vision system for required inspections. Material may be absorbent of one color of light and reflective of another; therefore lighting color and angles should be tested and evaluated to develop the best solution.

Product presentation – The orientation of the product will help determine the angle at which a light and camera can access the inspection area.

For instance, if material contamination needs to be inspected on an unoriented round bottle, multiple cameras and light angles will be needed to discover a defect 360 degrees around the bottle.

Product types – If multiple products are running on a single line, all products must be evaluated to determine adjustability, lighting solutions, resolution, and number of camera needed to perform inspection of each product.

Throughout the lab evaluation, the environmental factors, line speed and the product handling solutions on the line must be considered. These are critical to setting the tolerances, the system must be set up against, tested to, and operated with.

Calculating camera resolution Defining camera type

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10: Building an Effective Vision Inspection Program

Product Placement/Presentation The vision inspection system needs to have a clear, unobstructed view of the target product being inspected.

This requires that the inspected product be consistently and properly positioned on the line, with consistent spacing between targets. If the product is not positioned in front of the camera consistently, problems may occur with measurements and focus.

Product evaluations conducted with precision measurement equipment in a laboratory setting allows for little error when determining the final inspection setup.

10.2 Selecting Optimum Line Placement for Inspections Selecting the line placement for a vision inspection solution is crucial to the performance and efficiency of both the production line and the vision system itself. Four factors play a role in the placement of a the solution

Space available Product placement and spacing Product development stage Facility environmental conditions

Space The vision inspection system must be installed in an area on the production line that can physically accommodate all of its components. Positioning of the camera and lighting relative to the product is important, and adequate space for effective positioning needs to be available so that sufficient light can be directed properly and consistently at the target, and the camera can achieve a focused, full-frame image.

The HMI for the vision system software is best located close to the inspection station to enable accessible fine-tuning and calibration of the camera and lighting to achieve the optimum images. The HMI interface must be located on the side of the line where it gives line operators the most convenient access. If possible, the electrical enclosure should be placed beneath the line, but it can also be remotely located if necessary.

For example, if a camera is set up to read a barcode on a product at a 2 inch focal length, and it gets presented to the camera at a distance of 4 inches, the barcode image will become distorted and could result in a false reject.

Similarly, if using the solution to confirm a measurement, a target object will appear larger in size as its position comes closer to the camera, resulting in potential false rejects or false accepts.

Product orientation on the production line also influences the location of the vision inspection solution. For example, if a system is designed with one camera inspecting a date/ lot code on a carton, the face of the carton carrying that code must be facing the camera in order for the inspection to take place. Products must be oriented to face the intended camera in order to prevent possible false rejects.

For products such as bottles with front and back labels, it is recommended that cameras be placed on both sides of the line and programmed with a “reversible” software facility that can recognize and inspect either label from either position, eliminating the need to orientate the product.

The “reversible” system can distinguish the front and back label, then perform the required inspections of both labels after doing so.

Space is also required for reject mechanisms that are placed downstream of the inspection area in order to relocate the defective product to a specific area.

It is worth calculating the spacing requirements for the system in advance of specifying it, to reduce the risk of rework required, once the solution is manufactured.

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Above: A reversible system compensates for either front or back of bottle being presented to either camera.

Products must have consistent spacing to prevent an overlapping inspection of two products in one inspection, which not only gives false inspection data, but also interferes with the rejection process, possibly leading to the rejection of both products. Products too close together may also cause obstruction of the camera view, especially if the camera is set at an angle.

Another common way to avoid product spacing issues is to locate the vision system directly downstream from an automated system performing a task, such as a filler, capper, leak detector or labeler. The product exiting one of these stations is typically already spaced sufficiently for the vision inspection solution to perform its inspections accurately.

Product Development Stage The vision inspection solution must also be placed to match the inspection required to the stage of the production process. For example the inspection of the sealing surface of a bottle must take place before the line's capper so the solutions can have a clear view of the sealing surface.

Above: Example of Bottle Spacing

Product spacing is also essential to the rejection process.

If there is a backup in the reject area of the vision system, a faulty product may be rejected but take a good product with it. Backup in the rejection area can also lead to allowing bad product to pass the rejection area due to triggering issues caused by the backup. Product spacing can be achieved through certain techniques such as speed offsetting conveyor transfers, timing screws, and brushes.

It is, however, possible to have multiple inspection stations, where one station does an inspection at one stage of the production process, and another at a later stage of the production process. For example, the sealing surface of a bottle is inspected as it enters the capper and then inspected again as the bottle leaves the capper station.

Environment / Operating Sensitivity The environment that the vision inspection solution operates in also plays a role in the location of the system. The chart below shows each significant individual environmental factor, its effect on the vision system, and a solution that can act as a safeguard.

Above: Timing Screw

Dealing with Environmental Conditions Factor

Effect

Solution

Product Handling

The way and the consistency that the product is displayed to the camera can directly impact the reliability and repeatability of the inspections

Include product handling as part of the vision inspection solution

Ambient Light

Variable light can distort camera image and lighting

House vision system within opaque structure

Dirt or dust

Excess dirt may cover lens, or contaminate inspection target

Place system in clean environment, house system within vision enclosure

Vibration

Excess vibration may cause inspection product to shake or move causing blur and product orientation problems

Isolate system from vibration shock, shock absorbent structure

Heat

Excess heat may cause electrical components and PC to overheat

Add A/C to electrical enclosure

Food Grade and/or Wash down

Excess water and chemicals for wash down may cause damage to vision system

Enclose all components in NEMA 4X, or IP69K grade material

Power/Air supply

Excess distance from power and air may cause delay in high paced lines

Drop supplies near elements being powered

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10: Building an Effective Vision Inspection Program

10.3 Mechanical and Electrical Design Once the line placement has been determined, the electrical and mechanical designs of the system can be finalized.

The electrical design must include all wiring, product tracking, and powering components for the vision inspection solution to operate. As for all electrical equipment, proper documentation, certification, and electrical drawings should be kept for the vision system.

The mechanical design can be set up to incorporate the cameras, lenses, distances, and lighting devices determined in the evaluation process. It is necessary to provide robust and flexible bracketry/structure to avoid physical interferences which cause unintentional movement of lighting and camera angles. It is also important to consider the solution's ability to be adjusted to manage different product shapes and sizes running on a line. The mechanical design must take into consideration the correct height and angle to maintain a consistent inspection on part changeovers. The lab evaluation and line placement selection will help to determine the required dimensions and flexibility the final mechanical design should have.

The next section describes some of the options when selecting the mechanical design of the system.

Frame design There is a range of options when it comes to vision inspection solutions frame designs. The type of frame chosen will depend on the space available, the type of inspections being performance, product handling requirements and the type of environment the solution is operating in. As discussed previously, all these variables would have been considered during the solution evaluation stage. The following are a summary of the options that are available to manufacturers.

The vision enclosure requires sufficient head space to fit above the conveyor, while providing enough room for maintenance and adjustment access.

Inside other line machinery A vision inspection solution can also be installed into other line equipment, such as a labeler or cartoner. This alternative takes up the least space in the line, although it requires integration activity between the other line equipment suppliers and the vision inspection solution provider.

Fit to existing lines Vision inspection solutions can also be mounted directly onto the production line conveyor, or to the floor space under the conveyor. These types of installations can be optimum for space limited applications, although the final solutions will be subject to the influences of the production environment, like vibration from the conveyor, ambient lighting, and dirt.

These solutions might require some modifications to the conveyor frame such as drilling holes, redirecting wiring, or mounting the timing equipment (encoder).

Product handling

Complete vision inspection solution To ensure that the solution performs a quality inspection every time, the vision inspection solution would be installed fully-enclosed (as seen in figure 10.1). The enclosure provides protection for solution from the ambient light and environmental factors, increasing the solution's overall repeatability and reliability. These types of solutions can be mounted over the existing production line conveyor or with a product handling solution, dependant on the product presentation requirements specified during the evaluation stage of the project.

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Figure 10.1

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As discussed in chapter 7, product handling of the product can have a major impact on the quality, repeatability, and reliability of the inspection the vision inspection solution performs. Variation in how the product gets presented to the solution will lead to false rejects, and potentially false acceptance of product.

Anti Vision Circumvention Technology Operators may try to bypass the system in order to meet their production goals, oftentimes at the expense of product quality. Anti Vision Circumvention Technology prevents production crews from bypassing the vision quality checkpoints by monitoring product flow.

Pros and Cons of Installation Types Installation Type

Pros

Cons

Use existing bracketry Automated positioning and adjustment Communication and connectivity Enclosure already provided

Tight spacing Difficult to install on pre-existing machinery Expandability limited inside machinery

Inside Machinery

Vision Enclosure

Protection from environmental factors Protection from physical displacement of equipment Robust placement of equipment Modification to existing line unnecessary

Might require additional spacing

Mounted Directly to Line

Limited space required Easily accessible

Limited environmental protection Interference from physical contact

Mounted Over the Line

Limited space required Easily accessible Conveyor does not cause vibration

Limited type of inspections Limited environmental protection Interference from physical contact

10.4 Training To ensure that the equipment is being used and operated correctly, it is recommended for the operators using the equipment to be trained on it. This is one of the key factors to increase the repeatability and reliability of the equipment. A typical training course should contain:

Operation basics Power up and shut down Log-in/log-off Part changeover System safety Product flow Equipment overview Hands-on test

10.5 Documenting the Program No matter the size of the organization implementing the vision inspection program there should be clear document controlled policies and procedures. Thorough documentation will be a valuable safeguard if a company is under scrutiny due to a customer complaint, and to ensure quality product leaves the factory.

Documentation should include:

Lab evaluation results

Solution specification

Design of vision inspection solution (drawings and photographs)

Installation and commissioning of vision inspection solution

Tests and audits of vision inspection solution

Rejects, both false and verified (see chapter 13)

Data Analysis (see chapter 14 ) Records Records should be assembled and maintained to provide evidence of an effective vision inspection program. The records need to be organized, identifiable, and retrievable.

The following are types of documentation and record features provided by a vision inspection system.

1.

Permissions – A vision inspection solution will be operated by several people on the production floor.

A system has the ability to have multiple passwordprotected users with designated permissions per user. These permissions allow only select people to make critical changes to the system such as measurement tolerances and inspection types.

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2.

3.

Adjustment Logging – A vision inspection solution will log each event in data log files in the system.

If tolerances or inspections are turned off, data logs will specify the person, time, and date of occurrence.

Data Logging – A vision inspection solution will log the inspection results, including part measurements, types of defects detected, pass/fail rates, and number of products inspected. This data can be sourced into data management systems. (See Chapter 7)

10.6 Importance of connectivity The benefits of installing factory management systems and integrating vision inspection solution equipment into these systems improve overall production efficiency. A welldesigned system can include the capability of:

A typical manufacturing facility brings packaging material from many external suppliers, which are used in critical processes. Defects in these materials can cause production issues.

If the defects in the incoming products are detected in advance of it being introduced into the production process, cost can be saved by not having defective packaging cause:

Product to spill on the line.

Damage or jamming to down stream equipment.

Work performed on a product which is only later to be rejected.

Remote equipment management: changing of product inspection setting

Remote servicing and data backup: online diagnostics from the solution provider

Data collection and recording: recording of performance data, test routines, and vision inspection images. Providing proof of risk management and compliance with industry regulations.

These defects can cause a variety of problems, from loss of product through rejected defects to machine damage.

It is important that the vision inspection program inspect these parts early in the process in order to prevent that waste and damage. It should also be part of the program's controls to require that suppliers also have vision inspection programs to prevent defective product leaving their facilities.

Defects caused from the production process

Data from a vision inspection solution can normally be retrieved straight from an external USB port or exchanged via an Ethernet port.

10.7 Preventing Typical Defects and Problems Vision inspection solutions can find defects in two areas.

The first is the material coming from suppliers and the second are those created during the production process.

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Every time a product or package is transferred from one process to the next on the production line, or moves to another line, there is risk of damage occurring. Fillers, cappers, leak detectors, labelers, conveyors and other product handling equipment are all potential sources of damage or mishandling that can cause defective to the product.

Most companies recognize the value of regular maintenance and adhere to scheduled routines of procedures. These maintenance programs can be guided or directed by the defects that the inspection system identifies.

Maintenance Procedures Should Ensure the Following

Product safety and quality is not jeopardized during maintenance.

A documented, company-wide, planned maintenance program is in place.

Clear instructions are available to maintenance personnel indicating what is to be done during planned maintenance (including strip-down and re-build).

Personnel are trained by the equipment manufacturer or by the company’s staff who have been trained by the manufacturer.

Procedures are established to ensure that jobs are raised and completed on time, and highlighted if they are not carried out for any reason.

A full test of all applicable systems is carried out following repairs, maintenance or adjustments Provision is made for the management of spare parts.

It is important that potential hazards such as defective machinery are reported as soon as identified. Once such feedback is received, it is important that necessary action be promptly taken. Changes in machinery can result in changes in the product properties such as color and shape.

Therefore, it is also essential that the vision inspection solution controls be reviewed and re-set to reflect the parameters of new or re-built equipment. A precise system is only precise when it is properly set up.

10.8 Inspection in Controlled Environments In today’s marketplace there is zero tolerance for any packaging defect that can lead to spoilage or contamination of a product, or to leakage of the product.

Companies recognize that the cost of such defects can include damage ranging from customer complaints to costly product recalls and/or lawsuits.

To guard against these losses, which can be catastrophic, brand owners establish strict standards for the packaging for their products, including ISO certification. They incorporate into their packaging and inspection programs the packaging tolerances that are necessary to preventing package failure. They also demand adherence to such tolerances of their packaging suppliers.

The inspection programs that implement these standards check bottles specifically for ovality, inside (ID) and outside (OD) dimension consistency of neck walls, as well as the External wall (E), Height (H) and Thread (T) measurements of neck threads. These are the areas that are most critical for preventing container failure. Measurements are not the only standard that vision inspection solutions can qualify. Grading of print quality such as barcodes presents an opportunity for a vision system to inspect and qualify.

Vision inspection for ISO standards Vision inspection solutions are also able to compile documentation that can be extremely valuable for assessing the success of the quality standards program and as a defense in the event of a complaint, lawsuit or regulatory inquiry. For packaging providers, they offer assurance to the end-user customer of the provider's strict adherence to ISO standards.

Vision inspection for Gauge, Repeatability, and Reproducibility (GR&R)

Gather a select amount of parts (preferably 10) Run through the system, exact positioning critical Run Calculations for 6-Sigma and Part/Tolerance Standards

GR&R with 6-Sigma and Part/Tolerance (PT) Ratio Standards A useful definition of measurement “accuracy” and “precision” is the 6-sigma repeatability of a given measurement. This definition assumes a normal distribution of measurement values when repeated measurements are made of the same part, and corresponds to the area under a Gaussian bell curve of such measurements that contains 99.73% of all measurements. 6-Sigma is a real-world measurement range of values, for example with inch or millimeter units, and can be expressed in the form of either a +/- dimension around some central measurement value such as +/- 0.5 mm, or more usefully as the full 6-sigma range, in this case 1.0 mm.

If one takes the 6-sigma repeatability range of a particular measurement tool, divides this value by six to obtain sigma, and then squares sigma, one obtains the statistical “variance” of the measurement. 6-Sigma and variance are two sides of the same measurement coin. For example, a 6-Sigma range of +/- 0.1 mm = 0.2 mm corresponds to a measurement variance of 0.00111 mm2.

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measurement must bear an appropriate relationship to the range of acceptable measurement values. One useful way this relationship can be described is in terms of a measurement’s “P/T” ratio. The “P/T” ratio is equal to the precision, or 6-sigma repeatability of the measurement tool, divided by the acceptable part tolerance range. Since both the 6-sigma repeatability and part tolerance range are simple dimensions, when divided they express a dimensionless number, typically expressed as a percentage.

For example, if a particular measurement tool has a 6-sigma repeatability of +/- 1 mm, and the acceptable measurement range for a particularapplication employing that tool is +/-5 mm around some nominal value, then the measurement can be said to have a P/T ratio of (2 mm) / (10 mm) = 0.2 = 20%.

because it focuses on print quality defects that can alter a barcode read.

A vision inspection system will use tools to grade a barcode based on the categories of the ANSI guidelines. The ANSI software tools use the grading system of 0 to 4 or expressed as a letter grade (A,B,C,D, or F) based on the measurements in each category. A grade of "C" or better should read on most scanners on the first try. Some packaging suppliers and their customers require a grade of “B” or better since this will allow more margin of error.

Barcode quality has become increasingly popular due to high-speed lines and real-time scanning. Print quality is essential and a vision inspection solution can help provide feedback to the label manufacturer or printer in order to ensure scanning efficiencies. The grading systems consistently predict the ability to scan a barcode.

10.9 Vision Inspection and HACCP

For every measurement application, a given P/T ratio must be specified at the outset of measurement system design. When the project is completed, one must be able to demonstrate conclusively that the measurement accuracy of the system is no larger a fraction of the acceptable range of measurement values than the specified P/T value.

A customer measurement spec should include a P/T ratio specification along with the usual +/- tolerance. The P/T ratio specification comes from the QC department, and is usually in the range of 10% to 33%. If it gets any higher, the value of the measurement decreases rapidly. At 100%, good and bad parts look the same.

Vision inspection for American National Standards Institute (ANSI) Standards for Barcodes Standards and guidelines for barcode quality have been established by ANSI (American National Standards Institute) and the UCC (Uniform Code Council) based on the most common UPC barcode. ANSI verification ensures compliance for suppliers and retailers of customers

HACCP (Hazard Analysis Critical Control Point) has now become part of most factory quality systems, as a result of legislation and an ongoing drive by manufacturers to ensure that consumers are protected from any possible hazards, and that their own brand images are secure.

When implementing a HACCP program, the GFSI (Global Food Safety Initiative) approved standards, including BRC (British Retail Consortium), IFS (International Food Standard), SQF (Safe Quality Food), or ISO (International Organization for Standards) 22000 are accepted by most retailers and in most markets.

There are 7 HACCP principles, used by each of the globally approved standards to outline how to most effectively use vision systems when installed as a CCP to protect against the hazards of label mix-up, label damage or poor quality labels that interfere with the communication of package contents.

In reviewing global recall statistics, it is clear that most modern factories are on the right path when it comes to hazard control programs for physical contamination.

The recall numbers each year are coming down, due to technology improvements and manufacturers effectively implementing strong HACCP programs (for more information, refer to Mettler Toledo’s metal detection and X-ray guides, available on the MT web site at www.mt.com/pi).

It is also evident from the recall statistics that manufacturers continue to struggle to effectively control the hazard of label

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mix-ups or label damage and poor quality. The threats to the consumer as a result of these defects include overdosing and consuming ingredients they are allergic to, both of which can have dire consequences. Clearly, in addition, such eventualities can also severely damage a brand image.

Vision technology can provide very effective solutions to help with these problems.

can be resolved quickly, consistent with minimal impact on manufacturing, and minimizing the risk of the hazardous product being introduced into the supply chain. Some of the sources of hazards are:

The 7 HACCP principles

Conduct a food safety hazard analysis.

Identify CCPs (Points at which a hazard is optimally controlled).

Establish critical limits for each CCP. Establish CCP monitoring requirements.

Establish corrective actions.

Establish record keeping procedures.

Establish procedures to verify system is working as intended.

Vision and HACCP The following takes the reader through each of the 7 HACCP principles, outlining things to consider when implementing vision technology as a CCP to prevent label mix-up, label damage or other label quality issues.

1) Conduct a food safety hazard analysis

Food manufacturers must not fail to look into the full spectrum of hazards when implementing their HACCP program. At the end of the day, the impact of a hazard reaching the market can have severe impact on a company.

Some of the hazards that vision systems can help mitigate include:

Readable expiration date;

Incorrectly labeled product, which could mean that an allergen is not identified, or a dosage is not correctly communicated;

Labels applied incorrectly, so that important health information is not visible.

2) Identify the CCPs (Points at which a hazard is optimally controlled)

When identifying where the vision inspection system cameras should be installed, to ensure effective control of potential label hazards, the same logic applies as when determining were any other CCP is to be located. The CCP must be as close to the source of possible hazard as possible.

This allows the hazard to be tracked back to the source and

Operator error – where an operator loads the wrong label or does not change the label during product changeover; Equipment malfunction puts the label onto a package incorrectly, introducing a tear, or wrinkle; Operator circumvention, when operators try to fool inspection systems to reduce product rejects and meet demanding delivery schedules at the cost of quality and consumer safety.

3) Establish critical limits for each CCP

As we have seen above, a vision inspection system can monitor and control a large range of variables, depending on the manufacturer’s requirements. But when using a vision system as a CCP for either mislabeled product or incorrectly-applied labels, there are only “Go” or “No Go” conditions. Detecting and distinguishing a good package from a bad covers all failures.

4) Establish CCP monitoring requirements

The monitoring of vision inspection CCP must be linked to the manufacturer’s ability to recall product from the supply chain if a problem is found at the CCP. Industry experts’ recommendation is to test the vision CCP at an interval frequent enough so that, if there is a problem, the products manufactured between the time of the last test and the failed test can be recalled safely and reliably.

The practical reality is that a manufacturer is better off to have a higher testing interval then it deems necessary, due to the massive cost and effort of recalling product once it has left the factory, or the cost of missing a product that harms a consumer or causes a problem with a retailer.

For the first 3 months of operating the CCP inspection system after installation, it is advisable to make hourly checks at the start of each shift and upon product changeover.

As the operators’ confidence increases, we recommend increasing the interval to coincide with the manufacturer’s confidence in being able to recall products manufactured between tests.

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The testing procedure for a vision CCP is simply to introduce product that is verified to be good, marginally good, marginally bad, and bad by the quality team into the production line. If the good ones pass and the bad ones reject, the machine passes the test; if it fails, the line must be stopped and the problem needs to be investigated.

5) Establish corrective actions

When a hazard is identified by the vision CCP we recommend taking the following steps to mitigate risk to the consumer and the risk of a recall, beginning with evaluating the hazard and taking action:

A one-off label tear with a clear reason for it:

Continue production and quarantine the product for the quality team to evaluate. If multiple products are damaged, a line meeting must be called as soon as possible, ideally with the line on hold, to reduce risk of these products getting into the supply chain.

Multiple labels were incorrectly applied and rejected:

Vision system should automatically shut down the line A line meeting must be held quickly to get to the source of the problem before the line is impacted.

In addition to supporting HACCP audits, this documentation will also support manufacturers’ set-up activities, control internal quality procedures and help provide support if a problem is ever found in the marketplace.

If you would like to review an example of the types documents required to support your CCP installation in a HACCP audit, contact your local Mettler Toledo team.

7) Establish procedures to verify system performance

In addition to the monitoring procedures outlined in principle 4, it is also advisable that any CCP, not just vision, undergo at least an annual performance verification or, if operating in a harsh environment or dealing with a particularly dangerous hazard, bi – annual performance verifications. These performance verification checks will go a long way to increase the manufacturer’s, the retailer’s and the auditor’s confidence that the CCP is operating correctly and will increase everyone’s confidence that no consumer will be harmed.

Note: it is important for the end-user to keep in mind when installing a vision CCP that that the vision system is not restricted to monitoring only label mix-up or poor label application, but is also capable of adding much more value and security to a manufacturing line (see Section 1 above).

The operator circumvention warning goes off:

The line manager needs to remove circumvention devices and disciplinary action needs to be taken to prevent this from happening again.

Industry experience says that if these actions are dealt with immediately, documented clearly and are communicated to management, these actions will go a long way toward gaining the confidence of the auditors and help pass inspection without delay.

10.10 Pharma related standards The pharmaceutical manufacturing environment is very heavily regulated, and the equipment used in these manufacturing facilities must not only comply with these standards, but help the manufacturers with an easy simple implementation and operation of the equipment. Three of the key standards equipment suppliers must comply with are as follows: 21 CFR Part 210 and 211

6) Establish record-keeping procedures

The impacts on the manufacturer are: If your vision equipment is to be used as a CCP, your equipment supplier should supply the equipment with the full set of documentation, to ensure that correct procedures are followed when installing, setting up, commissioning, maintaining and testing the ongoing performance of the machine. These are all documents that the auditor will require when reviewing any of your GFSI HACCP based standards (BRC, IFS, SQF, and ISO 22000).

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Operators must be effectively trained on production equipment Be able to prove that the equipment specified is appropriate and the correct size Be located in the best place for its intended purpose Equipment is to be tested and calibrated by a certified technician at the correct intervals Equipment is not additive or absorptive to product

21 CFR Part 11

In addition the CFR regulations cover the use of electronic records and signatures under 21 CFR Part 11. This means that all software controlled hardware nust have traceable, auditable electronic signatures and records.

GAMP 4

All computer controlled equipment’s software when being developed must be designed per Good Automated Manufacturing Practices (GAMP) guidelines.

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11: Installation & Commissioning

Chapter 11 Installation and Commissioning 11.1 Installation The intended installation location and environment could potentially have an adverse effect on the operational performance of a vision inspection solution. Therefore, manufacturers' installation instructions should be consulted prior to and during actual installation. This will ensure that the best possible performance is obtained from the solution and the risk of false rejections during operation is minimized. Instructions provided by the solution manufacturer will contain more information than this guide can provide. However, there are general principles that can be applied to most vision inspection solutions. Gaining a basic understanding of these will help at the equipment selection and specification stage as well as at the actual installation. The basic guidance is as follows: Lifting the solution

In order to avoid damage, never pass any lifting slings or supporting equipment through the vision inspection solution’s central inspection area. Always lift the solution from the bottom, with a fork lift. When installing vision inspection equipment with a frame that can be dismantled, always handle the equipment via the frame and don’t lift by any of the lighting or cameras.

Equipment Access

Equipment should be positioned to give clear access from all sides for ease of cleaning, servicing and operation.

The installation should be capable of being easily cleaned and maintained without the need for dismantling during routine operations.

Vibration and Mechanical Shock

As far as practically possible, the vision inspection solution should not be installed in areas that are subjected to, or near, vibration and mechanical shock. Where this cannot be avoided, every effort should be made to minimize such effects.

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Clean Power Source

Power cable noise may arise from any significant changes in the loading of the electrical mains feeding the vision inspection equipment. This may adversely affect the performance of the equipment to a point it exhibits erratic operation, e.g. false rejections. The optimum power supply for a vision inspection solution is one taken from a source which supplies only low power equipment, is run through an uninterrupted power supply and is not connected to other power sources which are supplying varying current loads.

Installation Compliance

All aspects of the vision inspection solution should satisfy relevant legislation and retailer requirements in the country where the equipment is installed.

System Commissioning

Prior to operational use, the installed vision inspection solution should be commissioned to ensure that the installation complies with the manufacturers recommendations, the solution operates as intended and all relevant personnel are trained in its safe and proper use. The checklist below shows items for consideration during solution commissioning: Checklist

Solution and support documentation has been supplied Operation of solution has been satisfactorily qualified in the intended installation Solution is capable of reliably detecting and rejecting according to the defined defect specifications.

Operators have been trained to a minimum basic level (operation, care and day to day maintenance)

A trained engineer from the original solution manufacturer or its representative is the recommended resource to carry out the required commissioning process. Experience gained in other installations can enable them to identify

potential problems early, allowing the implementation of corrective actions to take place at time of commissioning.

Documented evidence should be generated to demonstrate that all key aspects of the installed solution have been satisfactorily qualified prior to operational use. This qualification should be considered specific to the actual installation location and surrounding environment.

Re-qualification of the installation should be considered in the event that there is a significant change in or around the installation or if the solution is moved to a different location. The operational aspects of the vision inspection solution should be re-qualified prior to running new or revised products through the existing installation.

Documented evidence should be generated to demonstrate that this took place.

11.2 Maintenance and Performance Verification It is important to ensure the solution is correctly maintained throughout its service life in order that it can operate at optimum performance with the maximum possible uptime.

The preventive maintenance program should include regular maintenance and performance verification checks of the vision inspection solution by a trained person. This should take place typically once every 6 to 12 months.

Ideally, this verification process should be carried out by a trained engineer in accordance with an agreed service contract. An experienced engineer can frequently identify potential solution and program problems and can suggest solutions before they become an issue.

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12: Performance Verification / Auditing

Chapter 12 Performance Verification and Auditing This chapter provides guidance on the essential elements of a verification procedure and the practical considerations necessary to not only demonstrate due diligence, but to also balance the frequency and complexity of testing with the associated benefits, costs and risks.

12.1 Verification Procedure Any vision inspection solution should be periodically verified in order to demonstrate due diligence and ensure that:

It continues to operate in accordance with the specified inspections It continues to reject defective product on detection of defects All additional warning/signalling devices are effective (e.g. alarm conditions, reject confirmation) Installed failsafe systems are functioning correctly

The verification and audit procedure should ensure that the company/line/product inspection standards are being complied with. It should be documented and communicated to all relevant staff and should be readily available for use by those responsible for conducting the necessary verification procedures and audits. As a minimum, the procedure should cover the following requirements:

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Test sample to be used Effective use of test packs (where applicable) Frequency of testing Number of tests Detector and reject device test methods Failsafe systems testing Treatment of rejected / suspect product (See Chapter 12)

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Guidance is provided below on the technical considerations and practicalities for each of these requirements.

12.2 Types of Test Samples to be Used The test samples to be used to test the solutions are

One confirmed good product One confirmed bad, for each defect type the system is inspecting for One marginally defective product for each defect type the system is inspecting for

The samples used during testing should contain the exact same properties as an everyday product on the production line, with the exception of the defect. The testing will be compromised if the product test samples do not exactly replicate the production line products. It is especially important that the reflective properties and shape of the product are exactly the same as the production line products.

12.3 Positioning of Test Samples During the testing each of the test products are to be placed on the conveyor in the exact same location relative to the inspection solution as each product that passes through the solution during production. Each of the defective products should be rejected and the good should be passed through. If this is not the case the vision inspection solution provider should be called to recalibrate the solution.

12.4 Frequency of Testing Procedures should clearly state when verification testing should be performed within the manufacturing cycle.

Consideration should be given to implementing verification testing at the following stages:

At the start and finish of daily production/shift At regular intervals during the production run (as necessary) At changes in production batches At changes in machine settings After downtime for repairs

Considerations for each of the above stages are defined below: Start and Finish of Daily Production/Shift Consideration should be given to conducting verification testing at the start and end of the daily production/shift to ensure that the vision inspection solution detects and rejects in accordance with the specification and any additional warning systems are functioning correctly, e.g. reject bin full indicator. In addition, any failsafe features which have been included as part of the system specification need to be verified at the start of each shift (see section 11.10).

If a failure is observed, then this should be corrected before commencement of the daily production/shift.

Regular Intervals during Production Run The frequency of verification during a production run needs to be defined within the procedure. It will ultimately depend upon the probability and consequences of a failed test. The following factors should be taken into account:

Quarantine period Customer, retailer and consumer brand codes of practice (if applicable) Margin of detection (see Chapter 9) Failsafe system design

Quarantine Period

The quarantine period relates to the time it takes to produce the maximum amount of product that is stored on the company’s premises before it is shipped. The verification period should be shorter than the quarantine period such that, in the event of a test failure, the product produced since the last successful verification will still be on the company premises, and can therefore be easily identified and isolated pending further action (see Chapter 12).

Customer, Retailer and Consumer Brand Codes of Practice

Customer, retailer and consumer brand codes of practice may well specify a frequency of verification greater than the quarantine period.

Margin of Detection

When there is a good margin of detection (see Chapter 9) and the systems will failsafe, there is potentially scope for reducing the frequency of verification tests based upon the fact that even if there are small changes in the solution, the vision inspection solution will still comfortably detect the specified test samples. Such decisions should only be taken when the margin of detection can be quantified and the risks are considered acceptable. It is worth noting, that in practice, the inspection standard may apply to many different solutions varying by manufacturer, type, age, reliability etc. The margin of safety therefore, may not be universal to all solutions.

Failsafe System Design

Robust failsafe system design and access control can be used to good effect in reducing the probability of a failed test and hence the frequency of testing. For example, if production line operators are restricted from making setting changes (e.g. lowering sensitivity by means of access control) then the potential for a verification test failure is reduced. Likewise, if the vision inspection solution automatically requests a verification test each time there is a product change, then this will limit the potential for a product to be run on the incorrect product memory selection.

Production Changes Consideration should be given to performing a verification test to confirm detection and rejection in accordance with the inspection standard whenever there is a change in product type running through the vision inspection solution. This is most important when the product type change requires a selection of a different product memory within the solution.

Setting Changes A verification test should be performed to confirm detection and rejection in accordance with the inspection standard whenever there is a change in the solution settings.

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After Downtime for Repair If maintenance work or repairs have been carried out on the production line during down time, the vision inspection solution and reject mechanism should be re-verified at the recommencement of production.

12.5 Number of Tests The number of tests to be performed should be derived from the confidence established during the original commissioning activity. During commissioning, the capability of the vision inspection solution will have been established. If there was good, repeatable detection capability, then this confidence should be carried through to production verification testing, i.e. if there is a good margin of detection on a single test, what is to be gained by conducting further tests? Alternatively, if a verification test is conducted and the test sample is only just detected, then repeatability may be questioned. Further testing may give greater confidence, however, if testing is conducted three times and the results obtained are one marginal detect and two good passes, then what is the statistical significance of this in relation to a high volume production line? Statistically, further marginal passes or even a misdetection could be expected. Therefore, the system probably does not have sufficient detection capability in the first instance and consideration should be given to increasing the frequency of testing. Three tests per product defect type would be considered the maximum practical level for production verification purposes. However, where good detection capability has been established during commissioning, one test per test sample would be considered as acceptable practice. The number of tests to be performed for each test sample is ultimately dependant upon the level of statistical significance that is required within the producer organization and to fulfil any external requirements.

12.6 Solution and Reject Device Test Methods Verification procedures should include precise details of the methods to be used. The methods will vary dependent on the vision inspection solution design and the actual application. In addition to ensuring that the solution is performing to the required sensitivity standard, it is important to test that the reject device is functioning correctly to ensure that it is still capable of rejecting the detected defective product. For example, it is common for conveyor speeds in plants to be changed for a variety of reasons. If this occurs and the reject timing is not suitably

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adjusted, it may be possible to reject the wrong product.

Similarly the air supply to an air blast reject device could be easily disconnected resulting in the failure to reject defective product. It is more efficient to devise a test method that tests the vision inspection solution (including the reject device) at the same time. All of the test products should be detected and rejected to the correct reject location for the test to have been successful. Should any part of the verification test fail, product manufactured since the last satisfactory test should be isolated and re-screened using a functioning solution (see Chapter 12).

12.7 Product Rejected During Normal Verification Testing Product rejected during normal test procedures, with no defects, should be placed back in the product flow prior to the vision inspection solution for re-inspection. Thereafter, it should be regarded as normal production.

12.8 Failsafe Systems Testing A test method should be established for each failsafe system built into the vision inspection solution. The following are examples of some common failsafe devices which may be incorporated into the vision inspection solution design and associated test methods.

Air Blasts or Punch/Pusher With Reject Confirmation

Testing should be carried out by passing a test pack down the line while temporarily interrupting the electrical supply to the reject device solenoid and observing that the reject mechanism does not operate and the conveyor belt then stops.

Reject Bin Full Indicator

This should be checked by breaking the beam for the required length of time and observing that the belt stops.

12.9 Vision Inspection Solution Manufacturer's Audit Audits of vision inspection solutions carried out by trained service engineers can provide an additional, valuable service in supporting the overall vision inspection program by ensuring equipment is in compliance with manufacturer’s recommendations and good practice. Experienced vision inspection experts can often spot potential problem areas and suggest solutions before they become apparent to the user.

12.10 Test Results The results of tests conducted should be documented to demonstrate that all requirements of the verification procedure were executed. These records should include the following:

Identification reference (e.g., serial number, CCP number) Product being produced Date and time of test Test samples used Name of the person who conducted the test Test result for both detection and rejection Test result for any failsafe devices Fault details and corrective action taken (as

applicable)

Should any verification or part of a verification test fail, then the cause should be immediately investigated and rectified before production re-commences. Product manufactured since the last satisfactory test should be regarded as suspect and treated accordingly (see Chapter 12). The details of the fault and the subsequent corrective action should be recorded as part of the test record. The accurate recording of test results is extremely important. In the event of a customer complaint or audit, a manufacturer may need to rely on these records to prove that procedures were correctly followed and the vision inspection solution was functioning correctly to the agreed inspection standard.

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13: Dealing With Suspect & Rejected Product

Chapter 13 Dealing With Suspect & Rejected Product If a vision inspection solution fails a periodic verification test, then the product that has passed through the system since the last test should be considered suspect. If product is rejected by the vision inspection solution during routine operations, then it should be considered as defective until proven otherwise. In both instances it is important that there is a clearly defined process for dealing with the product safety concern from the point of identification through to root cause investigation and final resolution.

This section aims to provide practical guidance in relation to those matters associated with the use of vision inspection solution. It intentionally does not cover more general aspects of dealing with rejected product (e.g., identification and traceability), final product disposal, and product recall.

Only authorized, trained personnel should be allowed to have access to rejected product and be able to undertake subsequent evaluation and investigations.

Controls should ensure there is no risk of mixing rejected product with good product.

production. In both cases the vision inspection solution should be re-verified prior to commencement of production.

The suspect product should be re-inspected through a known working vision inspection solution which has the same as the original vision inspection solution used on the product line.

Product that passes the re-inspection can be considered as being acceptable. Any product that is rejected should be considered as defective and subject to further investigation.

13.2 Treatment of Rejected Product

13.1 Action Required If a Verification Test Fails If, during a periodic verification test the vision inspection solution fails to detect or reject a test sample, then production should be stopped if it is a hazard to the consumer. Product produced since the last successful verification test should be regarded as suspect, identified accordingly and isolated from the rest of the production while awaiting re-inspection.

The cause of the failure should be determined and, if it is established that the failure occurred as a result of tampering or a change in production conditions, procedures should be established to prevent a reoccurrence. If the vision inspection solution can be adjusted to bring it back to correct operation, this should be done and be noted in the test records. If the cause of the failure is due to a system fault, then it should be repaired before commencing

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Any product rejected during normal production operation should be regarded as defective and subject to investigation.

The evaluation of rejected product should take place as soon as possible, ideally within one hour of rejection but certainly within that production shift, and before the product batch leaves site. Investigation immediately upon rejection would be considered as best practice.

The search for the defective products should ideally be carried out using the vision inspection solution which initially rejected the product. If this is not feasible, then an off-line vision inspection solution which has the same or higher operating sensitivity should be used.

If no defects are identified, then the product can be considered acceptable.

Best practice would be to dispose of any product that has been originally rejected by a vision inspection solution system after re-testing regardless of whether it is rejected again. However, this is not always economically viable, especially if a producer is incurring high levels of rejected product due to excessive false rejects. In such instances the producer must ensure that all reasonable measures have been taken to ensure the product complies with the stated sensitivity standard.

Finding and identifying the defects in the rejected product is important for the following reasons:

If the source can be identified, then steps can be taken to prevent reoccurrence If line operators can see the results, it will help build confidence in the vision inspection solution

13.3 Corrective and Preventive Action In the event that a defect is confirmed, procedures should clearly define the corrective and preventive actions necessary to procede. They should also confirm the persons responsible for determining the significance of the defects and having the authority to hold product and assign disposal.

Any defects found should be shown to line personnel so they build up confidence in the vision inspection solution and then be kept for future reference.

Procedures should clearly define under what circumstances production should be shut down, based upon the frequency of findings, and the nature of the defect type.

The results of any investigations, including details of defects found, source and actions taken should be fully documented for future reference and ongoing analysis.

13.4 Vision Inspection System Fault Condition Following the activation of a fault during a normal production process which results in a "stop production" situation, the necessary corrective action should be undertaken and the system re-verified. All of the product on or in the stopped process flow, including any downstream systems (where relevant) should be "collected" and re-passed through the vision inspection solution once the fault has been rectified and the system re-verified.

If a rejected product is confirmed to be defective, this should prompt an immediate risk analysis to determine the significance and potential for further product defect.

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14: Data Analysis & Program Improvement

Chapter 14 Data Analysis & Program Improvement The effectiveness of the vision inspection solution program can only be determined by efficient collection of data and trend analysis. Using this information over a period of time will help determine the effectiveness of the vision inspection solution program and, most importantly, will be the first step in quantifying, in monetary terms, the savings or increased profit generated.

This section highlights some of the typical data sources that should be analyzed with regard to reviewing the operational effectiveness of the vision inspection solution program and highlights some of the potential rewards.

the vision inspection solution program. The same principles can be applied to a variety of data sources.

14.1 Data Analysis

Each defect related to a customer should be investigated to determine the cause. The program documentation and records generated will greatly assist in the investigation and may even prove useful as evidence to defend an unjustified complaint or lawsuit.

Data can be collated, analyzed and used in many different ways. The most effective way to do this will vary from organization to organization and will be dependent on the needs and capabilities of the business. It is vitally important that there is integrity in the source data and the analysis is clear in terms of what it presents in order to achieve buy-in throughout the organization.

Corrective and preventive action should be taken as appropriate and the vision inspection solution program improved accordingly.

Communication of the analyzed data and resultant actions to those that are responsible for providing the source data will help to ensure the data flow is sustained. If it is seen that data is not being used to good effect, then its value will be questioned within the organization, resulting in reduced discipline in data collection and recording.

The number of complaints and assigned causes should be monitored over time to make sure improvement is being made and any underlying common causes can be identified and eliminated. Such actions can drive step-improvements in the reduction of complaints. The aim being to progress towards reducing them to zero.

Wherever possible, a cost element should be included in analysis data. This will have an increased impact on the prioritization of improvement initiatives and provide justification for additional capital expenditures.

Detection Events

14.2 Program Improvement The following are a few examples of the types of analysis that can prove beneficial in the review and improvement of

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Detection events are caused by actual defects or false rejects.

Detection event information should be regularly collated and typically monitored on a trend chart in order to identify common causes.

Analysis of defect type and frequency of events, line by line, or machine by machine, can identify particular sources of concern such as component supplier quality, inefficient

production staff/methods or inadequate maintenance routines. There should be clear distinction between normal production reject events and reject events that occur when carrying out routine verification tests.

Maintenance Records

Analysis of “false rejects� can prove beneficial in identifying poor installations and equipment that has become unreliable or solutions that can no longer cope with the operational tolerance imposed. Such data could be used as justification to upgrade to a more modern and capable vision inspection solution.

If the analysis of preventive maintenance records and incident reports highlights that a particular solution rarely needs any maintenance, then there may be sufficient justification to reduce the frequency of maintenance on the plan providing this is not contrary to the manufacturers’ recommendations or risk assessment.

Alternatively, analysis may show that there is often maintenance required and as such the frequency needs to be increased.

Verification Tests

General

The results of verification tests should be monitored and analyzed as an ongoing process. If there is a high frequency of testing being conducted (e.g., every 30 minutes) and the analysis over time shows that the tests are always positive, then due consideration could be given to reducing the frequency of testing.

There are numerous other sources of data that can be analysed to good effect. The key is to focus on the areas that can generate the greatest return in terms of increased profitability and reduced risk.

Caution should always be exercised to ensure that any external standards or codes of practice in place are not contravened and that the risks involved are known and acceptable.

Ongoing analysis of the program data can identify underlying common causes that, in isolation, do not appear to have great significance but when considered in terms of their frequency of occurrence become the incentive to take the necessary action to prevent occurrence in the future.

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Summary

Summary The summary of this guide

It is estimated that 85% of Vision System implementations do not meet or exceed the user’s expectations. Whether through poor planning, preparation or implementation, the user rarely realizes the full benefits that a Vision Inspection Solution can offer. As a result, they may be reluctant to utilize vision inspection in their quality programs. This guide was developed as a tool to better educate people so their expectations can be met.

A vision inspection system combines cameras, lighting, and image processing software to create an inspection system that is able to “see” objects and validate acceptability at high speeds with great accuracy. The heart of the system is the computer software-the brain that processes the image and evaluates against stored ideal images, measurements, and counts. The camera is the “lens” that captures and digitizes the image for high speed, quality inspections.

The guide has described key design features, how vision technology actually works, ways to build an effective program and the benefits of a implementing a vision inspection solution.

Mettler Toledo, CI-Vision offers expertise in all facets of vision system implementations that provide user friendly solutions for complex requirements combined with intimate industry knowledge. In addition, the company provides excellent project management services, technological innovation and breadth and depth of thirty years vision experience.

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Appendix A: Comparing Vision Implementation Strategies 74

Appendix A Comparing Vision Implementation Strategies As stated in Chapter 1, there are three ways to implement a vision inspection program: 1) doing it yourself (DIY); 2) using a system integrator; or 3) buying the inspection system from a vision inspection solution provider.

It is important to be aware of the range of required tasks and potential pitfalls each task may present while implementing a vision inspection program. Those responsible for the program should go into the project with a full understanding of all that is involved. The table below offers a summary list of activities that a successful implementation entails and an assessment of the difficulty level of each activity DIYers, integrators and inspection solution suppliers will encounter while implementing them.

Parts of a Successful Vision Inspection Program Implementation

Capabilities to implement Explanation

Resources Required

Do It Yourself

Integrator

Vision System Provider

Develop system specification Specification support - lab eval, report, environmental considerations

Each vision inspection application is different as a result of the type of packaging, resolution required, number of inspections, part size, and environmental conditions

Detailed understanding of lighting, cameras, the impact of the factory environmental conditions, and the hardware to support the evaluation

NA

Maybe - Difficult for someone with other technical tasks to keep up to date with the technology

Yes - Separate departments dedicated to these functions with a full time domain expertise

System mechanical and electrical design

Including electrical prints and CAD drawings, optimizing lighting and camera placement vs. product

A vision engineer, mechanical and electrical engineer

No - this is very difficult to do without a vision engineer

Yes - they need to have a vision engineer

Yes - Separate departments dedicated to these functions with a full time domain expertise

Frame design suitable for manufacturing environment

System to be designed to suit the environmental conditions, for example food grade, pharmaceutical, or other

Manufacturing engineer

No - Lack the engineering experience to properly design a full system to meet todays complex manufacturing codes.

Maybe - although they would need to have engineers who understand the different environments

Yes - Large base of customers gives the design department working knowledge of the solutions required.

System design

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Parts of a Successful Vision Inspection Program Implementation

Capabilities to implement Resources Required

Explanation

Do It Yourself

Integrator

Vision System Provider

System design (continued) Design to minimize foot print

Space is an issue on most production lines - the optimum system design will reduce equipment foot print

Detailed understanding of the space requirements to performance an effective inspection

No - without a good grasp of camera and optics technology, a DIY system would have little chance of being designed correctly while still optimizing it to fit spacing restraints.

Yes - but need to have a good grasp of camera technology and how to set focal lengths

Yes - understanding optics, lighting geometry, and camera sensor capabilities can allow for for 6 camera systems to be designed into 2' x 2' x 3' footprints

Flexible frame design

The change to product shape, size and type of label can mean that different cameras, lighting and geometry is required

To do this a good mechanical engineer who can design flexibility into the machine is required

No - without the understanding of how varying products can effect vision insepctions, a system would have little chance of being designed correctly while still remaining flexible enough to accommodate varying products.

Maybe - but needs to understand what the impact of changing the product has on the geometry of the cameras, and lighting

Yes - Can integrate multiple manual and automatic adjustment options

Product handling solutions

Ensure the correct product presentation to the camera, considering inspection location tolerances, and vibration

Vision engineer and manufacturing engineer

No - without knowledge of how product presentation effects vision inspections, a DIY system would have little chance of being able to address these very complex design constraints.

Maybe - although they need to have a strong grasp of the variables impacting vision inspection

Yes - Have used multiple transfer medians to inspect all the surfaces of various products

Integrated product rejection

Reject mechanisms need to be designed to suit and work with the vision system and type of product

Manufacturing engineer

No - most manufacturing facilities do NOT have an engineer capable of doing rejecter design.

Yes - most integrators should be capable of developing an efficient reject mechanism

Yes - A variety of standard reject mechanisms, as well as the ability to create custom ones to meet the requirements of the product

System set up / install / commissioning Factory Acceptance Tests

Using systems designed to test per factory environments

Factory representative conveyor systems

N/A

Maybe - If they have conveyor systems available

Yes - Utilize circle tracks to emulate production rates

System set-up

Build inspection recipes for the primary inspections to be tested at Factory Acceptance Test and delivered at installation

Vision engineer

Yes - although a vision engineer would be required

Yes - although a vision engineer would be required

Yes - Modular design and easy to use operater interface allows for quick redeployment of vision equipment at customer facility

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Appendix A: Comparing Vision Implementation Strategies 76

Parts of a Successful Vision Inspection Program Implementation

Capabilities to implement Explanation

Resources Required

DIY

Integrator

Vision System Solution

System set up / install / commissioning (continued) Site acceptance test - equipment testing/install

Ensure that a vision system is installed and operating correctly, includes product inspection, product tracking, and product rejection verification

Vision engineer and manufacturing engineer

No - Having an on-site engineer who understands the critical fuctionality of vision and how to properly setup, test and debug the entire installation is rarely found in a typical manufacturing facility.

Yes - although they need to have a strong grasp of the variables impacting vision inspection

Yes - Team of professional installers who are well versed in installation issues to make sure the install proceeds smoothly.

Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ)

Supporting installation and validation of vision equipment for auditors, this includes documented statistics of system operations including system validation test results.

Third Party installation team with equipment knowledge

None

Sometimes often written per job, adding cost and time to the implementation

Yes - Qualification and testing protocals have been developed for and deployed on multiple types of systems

Administrator training

To train the administrator on the details of how to set up parts and run the machine

Training tools, and knowledge of the system to train

Maybe - training manuals take time to develop and with other tasks on the table often don't get done

Sometimes - often written per job, adding cost and time to the implementation

Yes - Training by certified trainers available at the factory or dedicated training facilities available for off site training.

Operator training

To effectively and efficiently use the equipment operators need to be trained

Training tools, and knowledge of the system to train

Maybe - manuals take time to develop and with other tasks on the table often don't get done

Sometimes often written per job, adding cost and time to the implementation

Yes - Training by certified trainers available at the factory or dedicated training facilities available for off-site training.

Repeatability/ reliability

Slight changes in product handling, lighting/camera location and environmental conditions can impact the effectiveness, reliability of an inspection, and cause line stoppages

To limit the impact when the machine is designed it needs to be designed with large enough tolerances but still deliver a reliable inspection

No - this is very difficult to do without a vision engineer

Sometimes diificult to truly understanding the complexities of the repeatability and reliability of a system.

Yes - In-depth understanding and development of reproducibility and repeatability testing protocals are included in all gauging system development plans

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Parts of a Successful Vision Inspection Program Implementation

Capabilities to implement Explanation

Resources Required

DIY

Integrator

Vision System Solution

Supporting infrastructure Recommended spare parts package

A list of the parts which typically fail during long term use, based on reliability data generated over time

Many systems in use

Maybe - need the experience to know which parts fail

Yes - although need to have many machines installed to generate reliability data

Yes - All spare components are stocked and rapidly available world wide.

Service

To keep equipment running day in, day out it needs to be serviced correctly, including phone support, and annual maintenance

Well-trained service engineer with technical support, and team available over the phone to support

Maybe - In-house service engineers often don't have the technical depth required

Maybe - Service engineer who can fix equipment often don't have the technical depth required

Yes - Separate team of service personnel ensure service availability when required.

Operation manual user guide

Use in day-today equipment usage

Detailed system knowledge and documentation skills

None

Maybe - often written per job adding cost and time to implementation

Yes - Documentation department to ensure proper documentation which is easy to read and use.

User Interface

The ability to view and modify system performance and parameters, and to set up and select new products

Dedicated software development team

None

Yes - but usually lack consistancy of look and feel from set up to set up

Yes - Software team uses a feedback loop to improve standard HMI and make interactions as intuitive as possible

Vision Tools

The tools and algorithms necessary to find the required defects and/or measurements

R & D team dedicated to experimenting with the best possible vision algorithms available and determing how they should be integrated into the software package

None

Yes - usually rely on vision tools from one provider

Yes - Have the capability to integrate and utilize just about any vision algorithm or tool available from any source

Software

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www.mt.com/ci-vision For more information

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