Precision profiling

PRECISION

PROFILING WITH A BACKLOG OF ROAD MAINTENANCE JOBS ACROSS THE COUNTRY, LASER SENSORS AND SCANNERS CAN BE USED TO ENSURE SURFACES ARE CORRECTLY AND EFFICIENTLY MEASURED ON ANY ROAD PROFILING PROJECT.

On 26 February Infrastructure Australia released its priority list, a list that helps government and the private sector determine the country’s most important infrastructure projects.

The latest edition presented 147 infrastructure proposals of national significance, the largest number since the list’s inception.

This year, the list introduced five new high priority national initiatives, one of which was road maintenance.

Infrastructure Australia recognised the cost to maintain roads in Australia is growing and the overall maintenance backlog is increasing.

One of the major road construction activities that will be used in an effort to deplete the maintenance backlog is road profiling.

Depending on the level of damage, profiling can be used to remove layers of the road and in preparation for new products to be laid. With road construction materials varying across Australia, every road profiling job is different.

Wirhan Prationo, Bestech Marketing Engineer, says project managers need to be informed with the correct data of the pavement’s condition before profiling begins, and this can be done using sensor technology.

“Sensors provide measurements of the distance to the road which can be translated into roughness, depth and other datasets. This data can then be applied by engineers and operators to schedule proper maintenance when planning projects,” Mr. Prationo says.

Bestech Australia is a an Australian-based sensor, instrumentation and technical transport industry.

training company that supplies and supports a wide range of sensors and instrumentation for test and measurement applications, such as in the road and mounted on mobile and moving vehicles to get a rough estimate of the full-width road profile.”

“SENSORS PROVIDE MEASUREMENTS OF THE DISTANCE TO THE ROAD WHICH CAN BE TRANSLATED INTO ROUGHNESS, DEPTH AND OTHER DATASETS. THIS DATA CAN THEN BE APPLIED BY ENGINEERS AND OPERATORS TO SCHEDULE PROPER MAINTENANCE WHEN PLANNING PROJECTS.”

Specific for road profiling applications, Bestech offers two different types of noncontact displacement sensors from MicroEpsilon, the laser triangulation sensors and laser profile scanners. Mr. Prationo says these sensors are the most popular technologies in this field as they are easy to apply to road profiling projects.

“The single point laser or laser triangulation sensor, optoNCDT, is suitable for applications where the operators need to obtain only the rough profile of the road. Multiple single point laser triangulation sensors can be

The measurement results from laser

triangulation sensors can be displayed in the computer system or in a digital display through an analogue C-Box interface.

While laser profile scanners can measure road profiles in 2D, which Mr. Prationo says is a more detailed measurement compared to the single point laser triangulation sensors. sensor, it is also more expensive to apply. The scanning range of the Bestech laser profile scanners generally could not cover the full-width of the road.

“Multiple laser scanners can also be mounted and programmed for synchronous data acquisition to obtain the detailed profile of the road,” he says.

“The laser profile scanner, scanCONTROL, comes with a user-friendly and powerful interface software that can be configured individually to evaluate different types of road profiles such as depth, groove and gaps.”

He says contractors will generally decide which laser solution is best suited to each individual project.

“Usually road contractors will prefer to use laser scanners as this technology can give the complete profile of the road. However, using multiple laser scanners to measure the entire width and profile of the road can be costly,” Mr. Prationo says.

In some cases, single point laser sensors are an option to get a rough estimate of the road profile. Mr. Prationo says multiple single-point laser sensors are needed to get the rough profile and this is a more economical option if exact measurements are not required.

One of the challenges with road profiling he says, is that the sensors used need to be able to sample the profile data at a high speed. A sampling speed of 4kHz is generally sufficient to ensure accurate profiling.

For real time processing, both sensors also feature a ‘Real Time Surface Compensation’ function. This will automatically compensate for the amount of reflection from the target surface during continuous exposure and in real-time. It enables the laser to read accurately, even with rapidly changing surface types.

“As profiling works are commonly done during the day, a high-powered laser is required to ensure the sensors can get an accurate reading. The scanCONTROL scanners are available with a class 3B laser which is suitable for this measurement,” Mr. Prationo says.

However, he says operators running these lasers will need to exercise safety precautions when the laser is in use as it can be harmful to both eyes and skin, in close proximity.

“Alternatively, contractors can use a high-resolution laser sensor that can also provide accurate measurement results, which is a distinct feature of both our optoNCDT and scanCONTROL sensors,” Mr. Prationo says.

“Bestech’s laser triangulation sensor optoNCDT series are available with high resolution measurements and are adaptive to fast changing surfaces during profiling measurements.”

For increased accuracy the scanCONTROL laser scanner is also available in a SMART version that enables intelligence in the sensor heads and integrated controls.

“Engineers can program the scanCONTROL to automatically calculate any values such as gaps or edge angle through programable logic controller integration,” Mr. Prationo says.

“The SMART scanCONTROL with an integrated controller is preferred where the users have requirements to measure more complex profiles such as gap, edge angle, groove, and so on.”

If users want to know only the raw profile of a surface, the general scanCONTROL sensors are more suitable.

In Australia, there has been interest from the road construction industry in the Bestech laser sensors, one specific project looked at measuring the heights of a road curb.

“An application like this could be done by mounting the scanCONTROL on a mobile vehicle to scan the road as it moves. The laser scanners can automatically calculate the height of the curb through the userprogrammable integrated controller and give the readings to the operators,” Mr. Prationo says.

Other than laser sensors, Bestech also supplies a wide range of wireless sensors such as accelerometers and inclinometers for structural health monitoring applications and a range of other instrumentation and data acquisition systems for measurement of physical parameters.

For all applications, Bestech complements its products with technical support from factory-trained application engineers and product specialists.

“Our engineers can assist customers to identify and solve any test and measurement requirements that may arise from complex road profiling applications,” Mr. Prationo says. “AS PROFILING WORKS ARE COMMONLY DONE DURING THE DAY, A HIGH-POWERED LASER IS REQUIRED TO ENSURE THE SENSORS CAN GET AN ACCURATE READING. THE SCANCONTROL SCANNERS ARE AVAILABLE WITH A CLASS 3B LASER WHICH IS SUITABLE FOR THIS MEASUREMENT.” Bestech’s laser triangulation sensor is available with high resolution measurements.