DESIGN FOR MANUFACTURE BARC0060 THESIS PORTFOLIO: FINAL PROJECT 2018 - 2019
The Development of Flexible Fluidic Anisotropic Actuators for Large Soft Robots
LUTZ BARNDT
INDEX
INTRODUCTION
Flexible Fluidic Actuators Soft robots
TERM
Induction Project Innochain Conference Group Project: Vehicle Inflatables Report
SKILLS COURSES
Rhino / Grasshopper Photogrammetry Fusion / CNC Robotic Milling
SECOND TERM
Field Trip: Stuttgart / Switzerland Context Castings / Mechanisms
THIRD TERM Context
Concrete Studies Column Casting Robot
FINAL TERM
Robot Construction Thesis Report Robot Control Final Robot Execution
INTRODUCTION
FLEXIBLE FLUIDIC ACTUATORS Air — an element that has captured the fascination of many designers. A relationship can be made between air and mass/space or solid/void. Air is the medium of space, air is void. And the capture of that air is the ultimate control of the medium — and the designer’s frustration of every little hole that allows it to escape. The struggles of playing with air. Employing the intrinsic qualities of captured air in cushions and tubes. Orchestrating these creations to deploy, inflate and deflate. By introducing a control system that enables the cushions to develop a gait — to create “walking air.” In our exploration of capturing air, we discovered the field of soft robots. The dynamism of the many forces that act on the object conspiring to bring the creation to a halt. Soft robots offer the designer opportunities to explore electromechanics, physics, pneumatics, automation and bioinspiration.
Soft robots / Flexible fluidic actuators / Thermopolyurethane nylon / Bioinspiration
Image of Gripper structure in resting repose. The challenge of the actuator to hold fast to the object while allowing the soft robot the ability to move along the structure. L. BARNDT 2018 - 2019
We developed the FFAAs as a series, or linkage, of cushions constructed of a thermopolyurethane (TPU) embedded nylon fabric. The particular TPU nylon used in our experiments is 170g/m2 weight and 70den. Heavier material is available and may be used with final models to aid in the puncture resistance. One side of the nylon is impregnated with a TPU film. The two exposed TPU sides may be heat welded without melting the nylon to create air-tight cushions. Valves can be added and cushions can be designed to fit any need. BARC00600 Design for Manufacture
INTRODUCTION
FLEXIBLE FLUIDIC ACTUATORS “We define soft robots as systems that are capable of autonomous behaviour and that are primarily composed of material with moduli in the range of that of soft biological materials.” Rus, D. and Tolley, M. (2015). Design, fabrication and control of soft robots. Nature, 521(7553), pp.467-475. Soft robots have become increasingly popular in the development of autonomous machines. The term soft applies to the materials used and to the development of its parts. Nature has many examples of very efficient systems made up of soft materials. Many designs of soft robots look to nature for inspiration. A worm, caterpillar, elephant trunk, and octopus are some examples that are adaptive, flexible, and able to be employed in many environments. These examples have impressive strength and performance qualities yet have no skeletal structures and are not composed of ‘hard’ materials. The use of hard materials in the construction of industrial robots limits their use as we shall see. For interactions with industrial robots, considerations must be made for their working range. It is dangerous to be within the range of industrial robots. While robots are programmed with safety in mind, incidents may occur. The tool path may be designed by the operator, however, the path taken from the robot’s initial position to the actual work may move in a manner not anticipated by the operator. The future of robot design must consider the stiffness of the materials used in their construction. To determine material hardness, a standard must be established. Instead of relying on electric motors, soft robots use soft actuators to control their movement. These actuators are distributed throughout their bodies and generally define the design of the structure. These actuators can be divided into different categories and will be explained below. It is the aim of soft robots “to achieve better and simpler mechanisms by exploiting the mechanical intelligence of soft materials [09].” One example of these mechanisms can be seen below. This is an example of a simple soft-robot actuator. By increasing the air in the chambers, the structure is deformed. The volume of each chamber increases and the actuator bends. From a simple mechanism, movement is thus created. One can imagine whole structures being created from actuators such as figure E. Bending movements are very powerful in the natural world. For an example, an elephant trunk creates movement by orchestrating different muscles groups. While a trunk may not seem precise, it rarely fails to move peanuts to its mouth. It is this appearance of imprecision that describes an advantage soft robots have over hard. The elephant may move their trunk in infinite ways to achieve the same result. This is described as being hyper-redundant. This means the degrees of freedom are infinite compared to the six found in most articulated robot arms. “Soft robots are often characterized by distributed actuation and are fundamentally underactuated, that is they have many passive degrees of freedom. As a soft robot’s body becomes more compliant, its dexterity increases and this is a major advantage over traditional hard bodied robots.” Marchese, A., Katzschmann, R. and Rus, D. (2014). Whole arm planning for a soft and highly compliant 2D robotic manipulator. In: 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE.
Barndt, L. 2019. Illustration based on information found in Rus. D. and Tolley, M. (2015). Design, fabrication and control of soft robots. Nature, 521(75530, pp.467-475. This portfolio explores the application of flexible flu idic anisotropic actuators (FFAA), also known as a pneumatic artificial muscles. Based on smaller fluidic elastic actuators, this study examines FFAAs for use in large soft-robot design. Robots constructed by three-dimensional printing or soft lithography methods focus on silicone in their construction. This study replaces silicone with fabric-based analogies thereby reducing the developed weight of the robot. As computer simulations do not exist to visualise and optimise potential designs, full-scale models are created and tested. The developed FFAA actuators are then applied to a soft-robot design based on the caterpillar larva. The robot will be designed to climb structures with members of 500mm diameters. The potential robot may be used in construction or search and rescue operations. The images above display the movement of the geometer soft robot. The trunk central section contracts and causes the “ungripped” Gripper to move. As the robot development progresses, the strength of the actuators will be maximised to achieve other climbing strategies. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
INTRODUCTION
Flexible Fluidic Actuators Soft robots
FIRST TERM
Induction Project Innochain Conference Group Project: Vehicle Inflatables Report
SKILLS COURSES
Rhino / Grasshopper Photogrammetry Fusion / CNC Robotic Milling
SECOND TERM
Field Trip: Stuttgart / Switzerland Context Castings / Mechanisms
THIRD TERM Context
Concrete Studies Column Casting Robot
FINAL TERM
Robot Construction Thesis Report Robot Control Final Robot Execution
FIRST TERM
INDUCTION PROJECT The first project of Design for Manufacture, was one that was intended to get our feet into the workshop and begin to work with machines that we have never worked with before. I have had a good amount of experience working with wood and I wanted to explore some of the options of metal fabrication. I have always been impressed with Adler and Sullivan’s metal screens as seen here to the right. They were used at the elevator lobbies at the Chicago Stock Exchange Building. They always seemed so crafted yet still very rooted in the manufactured aesthetic. I thought that I would play a theme on the screen using metal profiles and bending metal strips to dance along the screen similar to Adler and Sullivan’s.
Image sourced from Dankmar Adler and Louis Sullivan - Elevator screen from the Chicago Stock Exchange (image source: Wright20.com. (2019). Wright: Auctions of Art and Design. [Online] Available at: https:// www.wright20.com/auctions/2012/06/important-design/242 [Accessed 23 Mar. 2019].
Image sourced from Cjmach.co.uk. (2019). Mach- Cut 2000mm x 6mm Hydraulic guillotine - Clarence Jones Machinery. [Online] Available at: http://www.cjmach.co.uk/new-machines/guillotines/mach-cut-nc-hydraulicguillotines/mach-cut-2000mm-x-6mm-hydraulic-guillotine/ [Accessed 23 Mar. 2019].
Image sourced from BS-916M, H. (2019). BS-916M, Horizontal Band Saw. [Online] www.equipmentsalesandsurplus.com. Available at: https://www. equipmentsalesandsurplus.com/product_p/1001740.htm [Accessed 23 Mar. 2019].
The images shown above show some of the shop tools that were used in the creation of the screen. The pillar drill was certainly one important one. I also discovered the wrong way to drill holes in sheet metal. Then the sheet metal pneumatic guillotine. As well as the horizontal band saw. These tools allowed me to create the pieces I would need for the screen. L. BARNDT 2018 - 2019
The pieces were made up of nuts and bolts holding together cut tube sections and pipe sections. The screen was mostly made up of 1mm thick sheet metal that bent to each section.
One all the metal pieces were created it was merely a simple assembly job. BARC00600 Design for Manufacture
FIRST TERM
INDUCTION PROJECT
Screen detail made up of standard parts. Thesis Portfolio: Final Project
Final screen structure displayed in studio space. The results were surprisingly stiff. One could see this being multiplied across a blank wall. L. BARNDT 2018 - 2019
FIRST TERM
INNOCHAIN CONFERENCE - COPENHAGEN, DENMARK The first field trip for Design for Manufacture was attendance at the Innochain Conference 2018. The conference took place in Copenhagen, Denmark at the Danish Architecture Center. The theme for this conference was “Expanding Information Modelling for a New Material Age.� The keynote speakers included representatives from Shigeru Ban Architects, AKT II, and Fosters and Partners. The conference lasted two days in which we were exposed to many different presentations and workshops from different firms and universities
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
FIRST TERM
INNOCHAIN CONFERENCE
Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
potholes and even steps on our way which can distract us or prevent us from doing anything else such as checking mobile phones, emails and etc.
FIRST TERM
GROUP PROJECT: VEHICLE We need to MOVE in our everyday lives. Usually there are many bumps, potholes and even steps on our way which can distract us or prevent us from doing anything else such as checking mobile phones, emails and etc.
2nd principces - What's the shape
Harper's monowheel: around 1892.
Theo Jansen: Strandbeest
Barkow Leibinger_Kinetic Wall at the Venice Biennale
The vehicle developed into a giant deployable wheel. As the studies progressed the team moved towards a pneumatic solution for the deployable nature of the structure. L. BARNDT 2018 - 2019
Sketch images of intent for the vehicle. BARC00600 Design for Manufacture
FIRST TERM
Final model
GROUP PROJECT: VEHICLE
Structural analysis
Details of the wheel model.
The stages of the deployed vehicle wheel. Thesis Portfolio: Final Project
Detail sketches of possible connections.
Deployable framework
Still images taken from the movie displaying PE plastic bags that cause the vehicle model to be deployed. L. BARNDT 2018 - 2019
FIRST TERM
GROUP PROJECT: VEHICLE
The construction of the PE air bags that will cause the deployment of the Vehicle Structure
Final vehicle structure being deployed with sample TPU air cushions. L. BARNDT 2018 - 2019
The Vehicle Structure being deployed during the presentation.
Final vehicle model displayed in fully compressed mode. The white PE air bags are shown deflated above the vehicle. BARC00600 Design for Manufacture
FIRST TERM
GROUP PROJECT: VEHICLE
The sample TPU air cushions shown deflated and inflated. The constriction of the inflated cushions will be the mechanism of the deployable Vehicle.
Detail photography of the TPU actuators for the vehicle structure. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
FIRST TERM
INFLATABLES REPORT The research done regarding the inflatable structures for the vehicle were compiled into a single report. The information obtained regarding polyethylene (PE) and thermoplasticpolyurethane (TPU) air structures were compiled into a single report.
Inflatables - Methods and Materials
Inflatables: Methods and Materials
Design for Manufacture - Term 1 Project
A typical heat sealer is limited by the dimension of the sealer arm. The unit shown is 300mm wide. In order to create longer welds, another unit was modified. We removed the arm allowing us to weld in a continuous line at 300mm increments. In the removal of the arm, the relay switch can be relocated from inside the sealer. The sealer can then be operated independently of the application of the arm. The operator can set up the welded area easily before initiating the heat pulse.
Group 3 Lutz Barndt Sotiris Monachogios Matthew Osbourne Amir Arsalan Tahouni Jia Wan University College London - Bartlett School of Architecture
damaging the airtightness. Another method are grommets. A grommet can be placed in an area that has been sealed from the main air pocket. Again, protecting the inflatables air-tightness.
[name.name].18@ucl.ac.uk
A
Physics of Pressure The formula for pressure is as follows.
P = F/A
P
F
P is the resulting pressure
A
F is the force acting on a column of air
P
A is the area the force acts on the column
From this equation, we can minimise the pressure in an inflatable by increasing the area in which it acts. A force acting on a small area will create a greater pressure. Smaller areas can also lead to a puncture at the point of force. See diagram. The transfer of force on an inflatable is important to how it distributes that force. [03]
001. Model of deployed wheel using inflatable structures
While engaging in experiments and research, we discovered the abstract titled “aeroMorph” from a research group at MIT. This led to the discovery of our second inflatable material, Thermoplastic Polyurethane, or TPU [01]. TPU is a film that can be adhered to many different materials. It can then be heat welded to create highly durable inflatable structures. However, it is a difficult material to source. We found one company in Germany that sells it. Another drawback, is its expense compared to PE. We did not perform as many experiments with the TPU; yet, most of our findings can be applied to either material. This report is will begin by describing the materials and properties of the two inflatable materials. In addition, we will discuss the tools used creating inflatable structures. One key aspect of inflatables are the methods used for filling them. We will discuss a number of ways we have attached valves onto the structures. In order to apply our research, we will present a case study describing the inflatable shape needed in our project, and document its construction and attachment. The report will conclude with a list of our material sources and information references. 14 December 2018 Design for Manufacture - Term 1 Project
L. BARNDT 2018 - 2019
Materials, Properties and Tools Polyethylene Chemical formula (C2H4)n Melting point 115–135 °C
F=100
F=100
Physics of Melting P=100 The MIT aeroMorph abstract asserts that an inflatable will bend inward on the side that the heat is applied to the welding of an inflatable. This can be an important rule of inflatables. [01]
002. LDPE Material sold as Drop Sheet. Milky 1 white and semitransparent.
The simplest shape to make is a square pillow. Another inflatable shape is inside-out seams. Similar to pillow sewing, three sides are welded, then the structure is turned inside-out. The remaining seam 4 must be welded3normally. This method has potential drawbacks as the 3 which can be difficult corners on the final2weld have four layers of PE to weld completely.
1
Polyethylene (PE) is a thermoplastic which means it can be heat weldPlan of IS ed. The best tool used for this material Scale 1:500is a heat sealer. A heat sealerPlan of IS is a device that sends an electric impulse across a nichrome wire. TheScale 1:500 One quarter revolution wire converts the pulse into heat while a mechanical arm presses the One quarter revolution PE material together. This results in the PE sheets being welded at a remarkable strong linear connection. 100mm min. 100mm min.valve valve
Detail Plan of IS
Scale 1:125
Detail Plan of IS 500mm
typical
Scale 1:125
003. 300mm Heat Sealer with adjustable heat gauge. A cardboard table was added to stabilise welding material (left). A Modified Heat Sealer with arm and trigger removed (right).
007. Thermoplastic Polyurethane, TPU, sample inflatable with valve (left). The thermal sealing iron (right) used to weld seams of the TPU together.
A=10
A=1
Physics of Shape We had tried many shapes of inflatables; however, we were limited to linear welds due to the nature of the heat sealer.
2
Paper Blocking One technique that we employed often was that of paper blocking. Placing a piece of bond paper between the layers of PE, before sealing, the weld does not take place. This allowed us to inflate objects quickly without need of further valves. This will be discussed further in the section on valves.
A=10 F=100 P=10
Polyethylene, or polythene, is the most common plastic. It is used for bags and films. [02] Most of the material we used for inflatables was sheet polyethylene sourced from B&Q. It is sold as a dust sheet and has a milky white appearance. It can also be purchased in clear and black. It is labelled as LDPE, which is low density polyethylene. The thickness is 50 micrometres, which is slightly thicker than a typical supermarket bag. DOW Chemical has an entire spreadsheet of technical data online. A link to this information can be found in the resources section.
P=100
005. Heat welding channels for attachments to inflatable (left). Grommets are used when a seal is created stopping the inflated air from escaping.
The process of welding TPU is much easier than PE. By placing the TPU sides together (shiny sides), the seams are ironed with a thermal sealing iron at its highest setting labelled 200° C. The side of the iron can be used for detailed work. It can take over a minute for the seal to adhere. After the seam has cooled, it can be tested for leaks. If a seam gives, it can be ironed and tested again. The resulting seam will be adequate.
F=100 A=1
300mm typical
We were led to the implementation of inflatables by the evolution of a group project creating a vehicle. We designed an all-terrain vehicle that could navigate the uneven surfaces by the deformation of inflatable structures. In our research for materials that could satisfy our parameters, we discovered two likely candidates. Polyethylene, or PE, became a good choice as it is an inexpensive and ubiquitous material. PE can be joined by heat welding. This led to the further study of the material and its properties. It is the purpose of this report to describe the conclusions of our findings in the following areas: Limitations of the heat welders Temperatures of PE welding Study of different methods of valving inflatables Tools used Different attachment methods Sources for fittings, tools and accessories
300mm typical
Introduction
proper tool. The iron is also smaller and more nimble than the heat sealers. TPU can be bought applied to one or both sides of the carrier fabric. We used 275g/m2 nylon with TPU coating on one side. Cost is another drawback with TPU. The 275g/m2 nylon cost £11.25 per square metre from extremTextil. As a comparison, PE costs only £0.57 per square metre. ExtremTextil also have other TPU backed nylon ranging from 70 to 650g/m2. It can take up to four days to order. It would be interesting to source more TPU and further experiment with the material.
F
MArch Design for Manufacture
Inflatables - Methods and Materials
P=10 006. Plain paper used to block the welding process. This provides a small slot for inserting air nozzles for quick studies. TPU (Thermoplastic Polyurethane) The use of PE could be considered the study model. TPU is an excellent material for the final model. TPU is a film, similar to hot glue, that can be heat applied to almost any fabric. It is often used in the construction of inflatable rafts or waterproof bags. Below are some qualities that make TPU applied materials superior to PE for inflatables. 4 Resistance to friction and tearing Soft, elastic and good flexural strength Resistance to cracks, good tensile property, and elongation coefficient Cold resistance (< -50ºC) Low shrinkage and transfiguration rate after long time compression Resistance to oil Resistance to oxidation and aging [04]
F F
A A
P P
However, TPU can be difficult to source. Small amounts can be found grommet, typical on all four sides 004. grommet, Simple cushion with welds typicalmade of two sheets through model shops as the material is used for wing construction (left). Inside-out cushion with three sides folded inside with the final in remote control airplanes. Larger amounts were found sold online weld on the outside (right). 500mm Note: Gray lines denoteinheat welds through the extremTextil website. Alibaba.com supplies Germany typical Note: Gray lines denote heat welds TPU; however, requires large order sizes. The inside-out method also limits the area for attachments to the inThe construction of TPU inflatables are similar to PE ones. TPU, as flatable. Flaps on the outsides of the welds offer good places to attach a material, offers the user more shapes options as the glue in TPU is the inflatable. One method is to create a channel between two rows activated over a longer time period. Overheating is difficult with the of welds. One can feed an attachment through the channel without 14 December 2018 Group 3 Lutz Barndt Sotiris Monachogios Matthew Osbourne Amir Arsalan Tahouni Jia Wan
F=100F=100 A=1 A=1
F=100F=100 A=10A=10
P=100P=100
P=10P=10
TPU can be adhered to PVC, ABS, leather, paper, nylon, polyester, cotton, silk, lycra, wool, rayon. The MIT aeroMorph study used a CNC table with a heated ball transfer to apply TPU to paper. When the structures are inflated, wonderful kinetic origami shapes are created. They also developed a software system that could predict the shapes from the applied heat welds. [01]
Valves
Design for Manufacture - Term 1 Project
To inflate an object, a tube is used to supply air from an air compressor or a foot pump through the valve. We have opted to use 8mm (outside) diameter plastic tubing. 6mm would have been another good choice as the fittings are smaller. 6mm tubing can be fitted inside 8mm tubing to step down (change) the tubing diameter. PVC clear plastic food grade hose/pipe was purchased through eBay.
008. Standard male stud valve. Studs and one-way valves The most common valve we utilised is the male stud. It is a fitting that attaches to the inflatable and allows the tube to be held in place while inflating. When the tube is released the air will not remain in the inflatable. One-way valves can be found which will inflate the object and not release the air when the supply tube is removed. However, they are more expensive, larger and can be easily purchased incorrectly. Any one-way valve used for vacuums will not allow air into the inflatable object. One-way valves have an indicative arrow etched onto the surface of the fitting. There are two types of arrows that are used. A simple standard arrow describes the direction air is allowed to flow. That direction cannot be reversed. The second type of symbol is a hydraulic circuit symbol. 009. Hydraulic nomenclature for a one-way valve. It appears to point to the direction of flow, but actually it symbolizes the ball stopping flow. The symbol shown above will restrict flow from right to left but allow it from left to right. Below are two one-way valves used for a vacuum and will not allow air into an inflatable. [09]
“A valve is a device that regulates, directs or controls the flow of a fluid,”[05] in this case air. Valves can be tricky with PE material. Below are some of our findings. Valves can be sourced at a number of places. EBay seems to have good selection. It is important to understand the nomenclature when purchasing fittings. The valves used in this report are described as pneumatic push-in fittings. One side of the valve receives the tube and the other side is attached to the inflatable. The threads used on the valve are described as ⅛ inch BSP. BSP stands for British Standard Pipe. It is an international standard (for the UK and Commonwealth countries) to describe screw threads for sealing pipes and fittings. The United States uses a NPT standard and will not be referred to in this report. The ⅛ inch BSP is merely a short-handed description of the threads. Sometimes the threads are described as BSPP which is BSP parallel. It is parallel that is preferred. BSPT refers to a thread that is tapered and is not used for these types of valves. It is also helpful to know when the washers and fittings are purchased. [06][07]
010. Both valves shown are vacuum valves. The left valve displays the hydraulic symbol for the one-way direction.
EBay and RS Components are both good suppliers for these valves. One-way valves have another limitation. They will allow the air into the object, but then will not allow air out. If the object is over-inflated, it will remain so unless another valve is used that can release the air. Below is a one-way valve that functions correctly. It has two push-in ends which make it easy to employ.
14 December 2018 Group 3 Lutz Barndt Sotiris Monachogios Matthew Osbourne Amir Arsalan Tahouni Jia Wan
BARC00600 Design for Manufacture
F A
P
F=100
FIRST TERM
INFLATABLES REPORT
F=100 A=10
A=1 P=100 Inflatables - Methods and Materials
Design for Manufacture - Term 1 Project
011. Another one-way valve that can easily be reversed to fit the need. Both ends have the 8mm push-in valves. The valve could be installed in-line to the inflatable via a stud valve.
Design for Manufacture - Term 1 Project
017. Washers with integrated nitrile rubber gasket.
F 014.AInsert valve into the inflatable. Heat weld across the valve on P both sides. Remove the paper and test the valve with pressure. If air escapes, remove air, insert paper and seal again.
Flap Valves A simple way to introduce air to an inflatable is through a flap valve. It is merely an extended piece of material that can be pinched off after inflating to keep the air inside. There are two ways to do the flap valve. One is an integral flap and the other is added.
Inflatables - Methods and Materials
An integral flap is included in the cut-out of the PE material. See diagram below. The flaps are roughly 30mm wide. F=100
F=100
before the inflatable is sealed. Care must be taken to position the hole far enough away from any edges that will be seamed as the valve can restrict the sealing process.
019. Olfa circle cutter. An alternative to the nitrile washers are rubber washers. 10M rubber washers can also be sourced at AccuGroup. They can also be fashioned with a sheet of 1.5mm thick rubber. Clamping the rubber between sacrificial plywood, an 8mm hole can be drilled at random locations 20mm apart. A round hollow punch tool can be made from a steel rod. Cut 150mm length from a 19mm OD tube with 1.5mm thick walls. The outer edge can be ground to a point (see image). When the rubber sheet is released from the plywood, the punch can be used to create the washers from the sheet. [11]
Our team developed a scissor frame that will form a wheel when the inflatable structures (IS) are filled. The frame was designed and manipulated in the Grasshopper software. When the members are assembled, the required dimensions of the inflatables was determined. The IS will be a series of compartments joined by the same volume of air. The sealed triangular areas allow the IS to deform at the required locations and also provide an area to install grommets. The grommets will slide onto the rods of the scissor frame fixing the IS to the frame. The sealed triangles must not be closer than 100mm across from each other. During our experiments, when this dimension was tighter, the deformations of the inflating section caused a constriction in the air flow from one compartment to another. Below are the dimensions and the specifications of the designed IS.
1
012. The process shown to form an integral flap. Two sheets are cut with the flap location integral to the pattern cut. The sheets are then 1 2 3 welded as shown.
valve
016. Sample stainless steel locknut.
Putting a Valve Together The Best System for Valves for Inflatables A hole is cut in the inflatable material at approximately 9mm. A tight fit is best. An Olfa circle cutter works nicely. The valve must be installed
100mm min. grommet, typical
Detail Plan of IS
500mm typical
Note: Gray lines denote heat welds
020. Best practice for valve system with inflatables. The following section will document the final inflatable shape required for our project. It aptly summarises our research to this point.
300mm typical
An added flap is made separate from the object and seamed into the of IS by welding 50 x 150mm strips on both long final weld. A flap isPlan created Scale 1:500 sides. After the welds have cooled, the excess PE can be cut away One quarter revolution keeping as much of the weld as wide as possible. A piece of paper is then added inside the flap. This is added to the final weld of the inflat100mmthe min. weld arm. The valve valvethe paper is under able. It is important that typical will need welding on both sides of the flap. It is possible thatgrommet, some air will escape at the very corners of the flap. As the material is four layers 500mm Detail Plan of IS typical deep, it is a difficult weld. Another weld might be necessary to repair Scale 1:125 any leaks. Be sure to insert the paper blocking again. Flap valves were never tested with the TPU as the material is highly durable and holds the pneumatic valves very securely.
4
One quarter revolution
Scale 1:125
018. Process used to create rubber washers for valve system.
3
Scale 1:500
015. A successful valve can be held in place with a binder clip or rubber band. Locknuts Locknuts are purchased with the BSP rating that matches the male end of the valves. The locknuts will tighten the washers and the inflatable material to the valve which creates a tight seal. They can be ob4 tained at any hardware supplier. RS Components locknuts are thinner which decreases the weight of the valve assembly.
2
Plan of IS
300mm typical
P=10
Design for Manufacture - Term 1 Project
Case Study
The BSP threads are placed into the hole with corresponding BSP nitrile (or rubber) washers on both sides of the inflatable material. A metal locknut tights the washers and material to the BSP valve. Tighten the assembly as much as the inflatable material will allow being careful not to stress it. The inflatable can them be sealed and inflated.
A=10
A=1 P=100
Inflatables - Methods and Materials
P=10
Washers
Note: Gray lines denote heat welds While other materials
can be obtained with this designation (such as locknuts) metric washers are an exception. Metric washers are usually described as M4, or M10. The ‘M’ denotes the metric nomenclature and 10 denotes the inner dimension (in millimetres) of the washer with added tolerance. For instance, a M10 has an inner hole diameter of 10.5mm (the outer diameter is roughly twice the inner). A M4 has an inner diameter of 4.3mm and a 9mm outer diameter. For example, the outer diameter of the ⅛ inch BSP thread is 9.728mm. A M10 washer will create a tolerance, or gap, of 0.772mm.
013. Steps of the flap construction. First, the flap is sealed along the long edges. Then, the excess plastic is trimmed from the flap. A long slot of paper is inserted between the layers to stop heat welding across the valve.
However, some washers are also sourced with the BSP designation. The washers used in our experiments contained an inner nitrile rubber gasket. The gasket is thicker than the washer. When the washer is squeezed against the other hardware, the rubber creates an airtight seal. RS Components sells a nitrile washer kit containing 114 pieces. [10]
14 December 2018 Group 3 Lutz Barndt Sotiris Monachogios Matthew Osbourne Amir Arsalan Tahouni Jia Wan
Thesis Portfolio: Final Project
14 December 2018 Group 3 Lutz Barndt Sotiris Monachogios Matthew Osbourne Amir Arsalan Tahouni Jia Wan
14 December 2018 Group 3 Lutz Barndt Sotiris Monachogios Matthew Osbourne Amir Arsalan Tahouni Jia Wan
L. BARNDT 2018 - 2019
INTRODUCTION
Flexible Fluidic Actuators Soft robots
FIRST TERM
Induction Project Innochain Conference Group Project: Vehicle Inflatables Report
SKILLS COURSES
Rhino / Grasshopper Photogrammetry Fusion / CNC Robotic Milling
SECOND TERM
Field Trip: Stuttgart / Switzerland Context Castings / Mechanisms
THIRD TERM Context
Concrete Studies Column Casting Robot
FINAL TERM
Robot Construction Thesis Report Robot Control Final Robot Execution
SKILLS COURSES
RHINOCEROS / GRASSHOPPER: PAVILION EXERCISE To summarise the Rhinoceros and Grasshopper skills module, an exercise was given to construct a pavilion of ten metres square. The challenge was to populate the walls with openings derived from Grasshopper parameters. Then to add a roof that was to be tiled in another parametric fashion. The following pages display a rather awkward looking pavilion, but one that did stretch one’s skills in their general application.
By creating a “Parameter Zone,” one is able to define the dimensions and factors that will determine the outcome of the pavilion. Other parameters are placed within the remaining components, but those were deemed inflexible for this exercise. In this exercise the ‘x’ and ‘y’ directions define the footprint of the pavilion, and the wall height will determine the height of the wall. I wanted to impose a more complex geometry, so a battered wall is generated by the scale factor which increases the footprint at the bottom of the wall compared to that of the top of the wall. All these parameters can be adjusted and the resulting geometry will change to reflect the new information. The roof and columns of the pavilion are also based on factors related to the wall height, but did not need to be separate parameters on their own. The roof structure is a corbelled dome made up of ‘stick’ pieces. These pieces are shown here at the right in a rendered format. Rhinoceros is able to create rather nice quick renderings once the pieces have been ‘Baked’ from the Grasshopper program. The graphics in red do not exist in the Rhinoceros environment until the last component in Grasshopper is ‘Baked.’ Then that object becomes manipulatable in Rhinoceros.
The Voronoi wall. The Voronoi components are a geometry that is quite popular in Grasshopper. One establishes an area or plane in which the geometry is desired. The area is then populated with random areas in which the Voronoi geometry is applied. In order to create divisions or frames within the geometry, the centroids must be obtained through an ‘Area’ component. This component generates the centroid of the geometries and that can be used as the scale origin offsetting the divided areas without creating issues if the geometry is unable to be offset. Those geometries are then ‘extruded’ a distance larger than the wall thickness. Then the wall is created through a Boolean Difference component. L. BARNDT 2018 - 2019
The columns of the roof structure are also parametrically defined. A rectangle is offset from the wall geometry with enough factors to avoid collisions. Circles are then defined at the rectangle vertices. Those are moved in the ‘Z’ direction at a factor of the wall height. Then a circle is added at a midpoint level. This point is arbitrary and could have been added to the original parameters. However, there were plenty of parameters on the pavilion and these would just be buried inside the components. By lofting the circles, a tapered column is created supporting the roof structure.
In order to attempt a brick laying exercise for the roof structure. Instead of merely simple brick, the roof would be spherical geometry. A ring beam was created using three of the vertices of the rectangular roof trusses. A sphere was created using the beams centre. The remaining geometry of the sphere is then ‘contoured’ to the height of the roof tile ‘sticks.’ The dimensions of the ‘sticks’ was established in another parametric panel. Once the sphere is contoured the lines must then be ‘dispatched’ so that every other contour becomes a pattern that establishes the brick coursing. BARC00600 Design for Manufacture
SKILLS COURSES
RHINOCEROS / GRASSHOPPER: PAVILION EXERCISE
Above is a screen capture of the workspace of Rhinoceros and Grasshopper working together. Grasshopper allows one to create work flows similar to that of Excel Worksheets, yet in a graphic rather than arithmetic resolution. Bot programs run at the same time, while Grasshopper uses the Rhinoceros environment to display graphic results of components.
Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
SKILLS COURSES
PHOTOGRAMMETRY
Success!! The next steps are to progress to build a point cloud. A textured model would be the last step. L. BARNDT 2018 - 2019
Point Cloud results
Point Cloud results
Different export types of the point information displayed. BARC00600 Design for Manufacture
SKILLS COURSES
PHOTOGRAMMETRY
The information was then exported as an XYZ file and then brought into PointTools for further manipulation. Each line describes a point’s location in space in an X, Y and Z format. The last three numbers describe the point’s colour in an RGB format. The file is not very large and conveys an object’s surface and colour. Thesis Portfolio: Final Project
PointTools Workspace In the PointTools program, the extraneous points can be placed on different layers. The points for the object alone can be extracted and a new XYZ file can be created. L. BARNDT 2018 - 2019
SKILLS COURSES
FUSION 360 / CNC
Computer Aided Manufacturing, or CAM, is a process best done with AutoDesk Fusion 360. It is a web and cloud based program that allows one to build models and create tool paths used by Computer Numeric Control (CNC) machines and waterjet cutters. The program uses a unique system of captures of design history. Any changes that are desired can be achieved by layering back to the correct history sketch, modifying it, and creating a new outcome. One can create components with unique names and change them globally depending on the construction of the model.
Our first exercise on the program was given to us by the cut sheet seen above. The sheet was also created in Fusion. We also discovered how to create sheets such as this as well.
The block is first determined, length, width and height.
The corners are radiused.
The following images determine the tool paths required to create the sample piece. This is the roughing surface phase.
This path determines the pocket of the piece. The corners are not rounded to the desired radius yet.
L. BARNDT 2018 - 2019
The pocket is created.
The bit used to create the pocket was larger than the radius desired for the pocket. A smaller bit is obtained and those corners are then achieved.
Above, one can see the â&#x20AC;&#x2DC;sketchâ&#x20AC;&#x2122; layer that the outlines of the piece is constructed. From this basic background the images below were created.
The radii of the pocket are created.
The centre points of the holes are determined and then the voids are created.
Finally, the four corner holes are determined along with the entry and exit paths.
Simulations can then take place of each tool path. The program can gather all the tool paths and create a final G-Code that can be used to create the pieces in the CNC BARC00600 Design for Manufacture
SKILLS COURSES
FUSION 360 / CNC
The toolpaths were created for each of the features of the object. Each change of the tool must be numbered. This allows the operator to understand which tool will be used within the code and simulations. The knowledge of the tool will also determine the tool speed and use.
The toolpaths created for each pass of the object. Thesis Portfolio: Final Project
The G-Code was determined for all the paths. The different tools are labelled with â&#x20AC;&#x2DC;Tâ&#x20AC;&#x2122; as in T1. The tool can be seen in the code when visually checking for errors. L. BARNDT 2018 - 2019
SKILLS COURSES
Brief: Construct a 500mm square frame made up of two by four inch timber. The frame must consist of two different types of joints milled from the Kuka robot via paths created in Grasshopper.
mm
m 0m
500
50
02
01
03
04
ROBOTIC FABRICATION
The images above and to the left are taken from the grasshopper file used to create the tool paths for the frame. Above, the file can be broken up into three sections. The first section [01] contains all the parameters that were used to create the members of the frame. These values were then carried across to the second section [02]. This section is used to calculate the tool paths for the chord named 04. All the tool paths are gathered together and carried to the third section [03]. This section translates the tool paths to the robot. The geometry from section 01 is oriented to the tool table. The factors for the robot control are directed at this stage. Factors including robot speed, drill speed, tool tip length, file name and location, warnings, etc. are controlled in section 03. The robot simulations are also available in this section. Conflicts and issues can be tested, and adjustments can be made before actual milling occurs. The items on the left contain the parameters that can be adjusted across the entire grasshopper file. Factor of depth - Is a percentage of the width that determined the size of the joints. The Kuka kr60 with a payload of 60kg. The work table is also shown in this image.
Tool pose - The ‘z’ distance for the start and stop of the tool paths. Tolerance - From research 1.5mm was determined adequate for dado constructions. This was adjusted in further paths as will be described.
The tool attached to the robot is called the ‘end effector.’ In this image a milling bit and motor is attached that will produce our wood connectors. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SKILLS COURSES
ROBOTIC FABRICATION
The difficulties of the dado shape. The diagrams above show that the geometry of the tool tip which cannot match the intended shape. It was decided that the corners would be over-cut to avoid any post-operation tooling. Only half of the tool tip would be needed to enter the shoulder to allow the joint to function.
Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
SKILLS COURSES
ROBOTIC FABRICATION
03
03 02 01
02
01 Circle Joint - Male
Circle Joint - Female
The tool paths were determined for each joint. The joints start with a facing edge cut. Since two joints are to be cut at the same time, the length of each chord will be accurate. Roughing operations are second paths. Each pass is 1/3 of the tool tip diameter. The male joint has a final facing path between the shoulder and the circle. The female joint has a plunge cut to accept the circle as its final pass. This is merely a perimeter cut of 3 passes.
01
02 01
03
02
01 Facing cut. 02 Roughing pass to create a lap.
Dado Joint - Male
Dado Joint - Female
03 Plunge cut to create the dado if necessary.
The dado joints follow the same procedure. First a facing cut, then roughing the lap. The male joint is simple and required only 2 passes. The female joint required 3 tool paths; one to clear out the dado and the second to clean the edges. Each path occurred three times to remove the material in three layers to avoid material blow-outs. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SKILLS COURSES
ROBOTIC FABRICATION
The images show the second pass at the joints. The circle was adequate again; however, the dado cut broke out at the vulnerable flange. It is understandable that this might occur. The direction of the grain is opposite what one would normally expect with a dado. Further design of this joint would be required.
Assembly The members were sanded and the frame was assembled. The 0.25mm tolerance was a bit too tight at the circle joint. The 1.5mm tolerance member from the first pass was used to finish the frame.
The joints still show gaps, most noticeably on the circle joint. The dado joint, with the over-cuts, worked reasonably well. The outside lip is very vulnerable to shear as the grain does not add to the strength of the joint. If this joint was rotated, it would improve the strength of the joint and work with the properties of the wood. The circle joint was the most successful. It might be a good joint for robot construction as it has a simple geometry and is easily located in space.
The images above show the first two members cut with the tool paths. The circle seemed adequate. However, the dado side over shot the intended mark. It was also determined that the tolerance at 1.5mm was too great. It was reduced to 0.25mm for the other tool paths.
Circle Joint
Thesis Portfolio: Final Project
Dado Joint
L. BARNDT 2018 - 2019
INTRODUCTION
Flexible Fluidic Actuators Soft robots
FIRST TERM
Induction Project Innochain Conference Group Project: Vehicle Inflatables Report
SKILLS COURSES
Rhino / Grasshopper Photogrammetry Fusion / CNC Robotic Milling
SECOND TERM
Field Trip: Stuttgart / Switzerland Context Castings / Mechanisms
THIRD TERM Context
Concrete Studies Column Casting Robot
FINAL TERM
Robot Construction Thesis Report Robot Control Final Robot Execution
SECOND TERM
FIELD TRIP: STUTTGART / SWITZERLAND On the second field trip arranged by the university was a trip to Switzerland and Germany. While in Stuttgart, Germany many visits were arranged. The first was a trip to the robot factory and showroom at Fraunhofer. As seen in the images to the right, the development of robots in the industry were on display. The level of complexity and automation were an inspiration to the development of the projects this year. Next we visited the construction site of the ITECH University of Stuttgart pavilions. One pavilion utilised the epoxy process of creating shapes. The other used the optimised plywood sandwich construction to define an earth shelter. We also tour car museums such as Mercedes and Ferrari while in Stuttgart. In Switzerland a highlight of the trip was the tour of the Blumer Lehmann factory. We were introduced to the factories that created such structures as the Swatch Headquarters, the Tamedia headquarters as well as many Apple store interiors. The process and machines were another inspiration for the instruction of manufacture. We also visited the building of the Tamedia headquarters designed by Shigeru Ban and constructed by Blumer Lehmann. It was interesting to see the coordination between design and construction. And finally we visited the office of Design to Production. An interesting and direct application of the tenants described in our design for manufacture programme.
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SECOND TERM
FIELD TRIP: STUTTGART / SWITZERLAND
Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
AIM CONTEXT STATE-OF-THE-ART METHODS DEVELOPMENTS PROPOSAL OUTLOOK
SECOND TERM
CASTINGS / MECHANISMS
AIM CONTEXT STATE-OF-THE-ART METHODS DEVELOPMENTS PROPOSAL OUTLOOK
Smart Dynamic Casting, ETH Zürich , 2012-2015 Robotic Fabrication of Complex Concrete Structures
Concrete Forming Work, KTH, 2018 Parametric Patterning of Fabric Formwork for Cast Concrete
FIBERBOTS, MIT Media Lab, 2018 Design of a multi-agent, fiber composite digital fabrication system
SRS Circular Column Formwork from: https://cdn.peri.com/
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SECOND TERM
CASTINGS / MECHANISMS
Initial concrete casting experiments using polyethylene plastics and tubes to contort the concrete during its curing time. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
Comparison of pattern, fabric and final cast.
SECOND TERM
CASTINGS / MECHANISMS
Smocking Probe Patterns
Hand-smocked Probes
Final Cast
Flat Pours
Enlarged image of the smocking pattern concrete pours. The formwork was made of neoprene and allowed the smocking pattern to be transferred to the concrete with minimal destruction upon demoulding. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SECOND TERM
CASTINGS / MECHANISMS
Sketch diagram of sock formwork.
The “sock” form being rolled up. Thesis Portfolio: Final Project
The “sock” moulding system. In order to obtain a continuous mould, the Möbius strip of a neoprene sock was used as the formwork. After the concrete developed sufficient hardness, the formwork could be rolled up to the next pour location.
Detail of the “sock” formwork resulting concrete. L. BARNDT 2018 - 2019
SECOND TERM
CASTINGS / MECHANISMS
Continuing with the rolling formwork concept, a mechanism is created that can deploy a moving neoprene formwork. Multiple units are combined to create a round column formwork. L. BARNDT 2018 - 2019
The entire formwork assembled and ready to place concrete. BARC00600 Design for Manufacture
SECOND TERM
CASTINGS / MECHANISMS
Process of the mechanism moving along and creating a resultant column in its path. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
SECOND TERM
CASTINGS / MECHANISMS Continuing with a continuous mechanism to form concrete, a new mechanism was created. The intent of the mechanism was to create a pathway for a pattern to be applied onto the tracks of the mechanism which should result in a pattern being transferred onto the concrete.
Detail of the mechanism connections. It was proposed that the tracks could be motorised and move along the column as needed. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SECOND TERM
CASTINGS / MECHANISMS
T he single paths and the assembly process of the mechanisms are shown here. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
SECOND TERM
CASTINGS / MECHANISMS
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SECOND TERM
CASTINGS / MECHANISMS
The final mechanism is shown ready for the placement of concrete. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
SECOND TERM
CASTINGS / MECHANISMS
The process photography of the mechanism â&#x20AC;&#x153;extruding the concrete behind its path. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
SECOND TERM
CASTINGS / MECHANISMS
The final concrete pour. Thesis Portfolio: Final Project
Detail image of the concrete mechanism pour. L. BARNDT 2018 - 2019
INTRODUCTION
Flexible Fluidic Actuators Soft robots
FIRST TERM
Induction Project Innochain Conference Group Project: Vehicle Inflatables Report
SKILLS COURSES
Rhino / Grasshopper Photogrammetry Fusion / CNC Robotic Milling
SECOND TERM
Field Trip: Stuttgart / Switzerland Context Castings / Mechanisms
THIRD TERM Context
Concrete Studies Column Casting Robot
FINAL TERM
Robot Construction Thesis Report Robot Control Final Robot Execution
CONTEXT
AIM
STATE-OF-THE-ART
PROGRESS
PROPOSAL
THIRD TERM
CONTEXT
CONTEXT
AIM
STATE-OF-THE-ART
PROGRESS
PROPOSAL
Mark Burry Columns at La Sagrada Familia
Crushedwall, Walter Jack Studio. From: https://i.pinimg.com/564x/09/b4/ff/
CONTEXT
Concrete Forming Work, KTH, 2018 From: https://i.pinimg.com/8276s/102e/kut
AIM
STATE-OF-THE-ART
PROGRESS
PROPOSAL
CONTEXT
AIM
STATE-OF-THE-ART
PROGRESS
PROPOSAL
Mark West, The Fabric Formwork Book
UCD Architecture 5th Year Dissertation http://cargocollective.com/ciaranconlon/Research-on-James-Waller
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
THIRD TERM
CONCRETE STUDIES
Concrete pour experiments of spandex and circular tube formwork. Thesis Portfolio: Final Project
Detail of concrete surface using spandex material in the formwork. L. BARNDT 2018 - 2019
THIRD TERM
COLUMN CASTING ROBOT
A polyurethane plastic robot model was created to test the column crawling gait. A series of Arduino air pumps controlled by switches choreographed the movement along the sample column.
The development of the concrete formwork caster. The diagrams display the process the mechanism would transform in order to create a concrete column. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
THIRD TERM
COLUMN CASTING ROBOT
Detail image of column crawler. Thesis Portfolio: Final Project
PE model of column crawler with the pumps required to create movement in the small robot. L. BARNDT 2018 - 2019
THIRD TERM
COLUMN CASTING ROBOT
Diagram of pneumatic assistance to concrete “soft” formwork. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
THIRD TERM
COLUMN CASTING ROBOT
Plan of concrete column caster “elevator” structures. Thesis Portfolio: Final Project
Plan of concrete column caster “panels.” The darkened areas denote the heat seal of the TPU structures. The central areas contain the fixing structures to connect the caster to the other elements. L. BARNDT 2018 - 2019
THIRD TERM
COLUMN CASTING ROBOT
A sketch of a thought experiment for the implementation of the column caster robot. The experiment displays the possible deployment of the crawlers to pour concrete columns using a drum mixer. L. BARNDT 2018 - 2019
Column caster elements shown in deflated and inflated states. BARC00600 Design for Manufacture
THIRD TERM
COLUMN CASTING ROBOT
The air cushions are controlled by the switch / valve control panel shown above. The system provides the air or vacuum as the robot requires.
The flattened robot assembly. Thesis Portfolio: Final Project
The final column caster shown on a sample column. The air cushions are coordinated to climb the structure through an orchestrated series of inflations and deflations. L. BARNDT 2018 - 2019
THIRD TERM
COLUMN CASTING ROBOT
Previous Column Crawler
The images above show the column caster climbing up the existing column. All the actuation were controlled manually by the valve control panel. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
THIRD TERM
COLUMN CASTING ROBOT
Above is the state diagram which displays the process the column crawler uses to move along its concrete pour. This diagram is used to create the code seen on the left. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
THIRD TERM
COLUMN CASTING ROBOT
Control Systems: Electronics and Valves
Air Sup
Air supply
Air Valv
Air valves (12v)
Vacuum
Vacuum pump (12v)
Pressur
Pressure sensors (5v)
Relays
Relays (5 & 12v)
Micropr
Microprocessor
In order to organise the coordination the air cushions, a microprocessor was employed. A valve / control board is controlled by a microprocessor. Relays are used to control the valve solenoids. The relays determine the amount of air allowed into the air cushions as determined by the pressure sensors. A section of the code is shown above along with a debug screen which displays the state of the crawler and the associated pressures of the cushions. L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
THIRD TERM
COLUMN CASTING ROBOT
The process and final production of the concrete caster. Using quick set concrete, the process took over three hours of inflation / deflation and placing concrete. Thesis Portfolio: Final Project
L. BARNDT 2018 - 2019
THIRD TERM
COLUMN CASTING ROBOT
In critique with Sir Peter Cook, it was proposed that different events might happen along a path displaying the pneumatic devices. L. BARNDT 2018 - 2019
The column crawler might cause an umbrella like structure to open and close. Another event might deploy inflatable structures out from a central column. BARC00600 Design for Manufacture
THIRD TERM
COLUMN CASTING ROBOT
Proposal suggested for the use of air structures and concrete formwork. Thesis Portfolio: Final Project
A sketch proposal was introduced for the possible use of the column crawlers. Deploying umbrella structures and air cushion fantasies emanating from a forest of columns. L. BARNDT 2018 - 2019
INTRODUCTION
Flexible Fluidic Actuators Soft robots
FIRST TERM
Induction Project Innochain Conference Group Project: Vehicle Inflatables Report
SKILLS COURSES
Rhino / Grasshopper Photogrammetry Fusion / CNC Robotic Milling
SECOND TERM
Field Trip: Stuttgart / Switzerland Context Castings / Mechanisms
THIRD TERM Context
Concrete Studies Column Casting Robot
FINAL TERM
Robot Construction Thesis Report Robot Control Final Robot Execution
Geometer Larvae Gait
FINAL TERM
ROBOT CONSTRUCTION
YouTube. (2016). Inchworm: Geometridae caterpillar. [online] Available at: https://www.youtube.com/watch?v=rcIbT6F0U1w [Accessed 21 Aug. 2019]
In the effort of making automated machines safer for human interaction, one must consider the materiality of the machine. It is the hard materials in industrial robot design that result in their accuracy. In the operation of industrial robots, humans must give the machine a work zone in which to operate. That space cannot be cluttered with anything except the work. As the machine is made of hard materials, any collision can be catastrophic for the object or the machine.
employed in a larger soft robot. By developing this actuator with light fabric materials, the enlargement can be achieved without debilitating heaviness. This report will then propose how the actuator may be employed in the development of a large soft robot. One that might climb columns in a building. By using the biological model of the caterpillar larva, a model can be created that might climb a structure using the caterpillar gait. The report shall begin by exploring what is a soft robot.
Biological inspiration However, it is desirable to have humans interact more with robots. If one creates more interaction with robots, then the robots must become compliant. Not compliant to the will of the operator but to the ability of the robot surface to give when collisions occur — to become soft. Soft robots designers have looked for autonomous examples for inspiration, often looking to nature. A whole planet of soft bodies exist to draw upon. Biological imitation will aid in the development of autonomous systems. As one looks at the biological examples that surround us, we might be peering into the future of automated machines.
Soft vs. hard robots - Industrial Robots
It is the intent of this report to explore qualities of biology that can be manipulated into the development of soft robots. The report begins with the discussion of industrial robots and investigates their limitations in regards to material stiffness. Then presents the current characteristics of soft robots and explores their inner workings including the actuator types that are available to the designer. The report will examine the further development of the flexible fluidic actuator. Specifically the enlargement of this actuator to be
“Industrial robots are optimised for precision, repeatability and reliability.” Gaiser, R., Ivlev, O., Andres, A., Breitwieser, H., Schulz, S. and Bretthauer, G. (2012). Compliant Robotics and Automation with Flexible Fluidic Actuators and Inflatable Structures. Recent Advances and Future Challenges. [online] IntechOpen. Most industrial robots in current use are made of metal and plastic components. Many have fixed bases or some may be tracked. By design they are heavy and cumbersome and their weight increases the stiffness of the robot mechanisms. Vibrations and deformations can be minimised which improves their accuracy and performance. Also, the work zone of hard robots must be uncongested. They are unprepared to understand obstacles, debris or people. Collisions can damage the machine or the errant person in its path. Programs may include obstacle avoidance; however, accuracy and speed will be sacrificed to do so. As one may enjoy watching the ballet of the automated arms assembling objects in manufacturing facilities, we must understand the limitations of these machines.
Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Barndt, L. 2019. Illustration based on Trimmer, B., Takesian, A. and Sweet, B. (2006). Caterpillar locomotion: A new model for soft- bodied climbing and burrowing robots. In: 7th International Symposium on Technology and the Mine Problem. Medford, MA USA: Tufts University. Examination of the many parts of the catepillar larva.
Design for Manufacture - Thesis Presentation Conference
Barndt, L. 2019. Illustration Diagram of caterpillar body parts.
Construction diagram of biomorphism employed to construct the geometer soft robot. L. BARNDT 2018 - 2019
Gripper diagrams shown displaying the required movements for a successful robot action. BARC00600 Design for Manufacture
FINAL TERM
ROBOT CONSTRUCTION Interpretation of the Flexible Fluidic Anisotropic Actuators
The silicone FEA actuators (below) inspired our development of effective actuators that are deployable at a larger scale. By replacing the silicone with fabric, we have successfully created a large actuator type that was very light. Upon further research, it can be concluded that the actuators fall into the FFA bending type actuator. As FFA actuators can be described as anisotropic, we wanted to distinguish the actuators developed for this report to include the anisotropic term. It is usually applied when discussing “where bending occurs due to ‘anisotropic membrane stiffness.’” Gaiser, R., Ivlev, O., Andres, A., Breitwieser, H., Schulz, S. and Bretthauer, G. (2012). Compliant Robotics and Automation with Flexible Fluidic Actuators and Inflatable Structures. Anisotropic is defined as objects that have physical properties which have different values when measured in different directions. Wood is a good example of this, as it is stronger in values taken along the grain as opposed to perpendicular Lexico Dictionaries | English. (2019). Anisotropic | Definition of Anisotropic by Lexico. [online]. Thus, actuators that develop a pulling strength only along the direction opposite to the limiting layer will be termed in this report as flexible fluidic anisotropic actuators, or FFAAs. One area of interest in the use of FFAAs, is the counterplay of two actuators. Applying biological terms, if two FFAAs are mirrored, they may be operated in an antagonistic manner. The contraction in opposite directions operate similar to muscle groups in an animal’s arm. A biceps that can lift, while the tricep pushes away. We developed the FFAAs as a series, or linkage, of cushions constructed of a thermopolyurethane (TPU) embedded nylon fabric. The particular TPU nylon used in our experiments is 170g/m2 weight and 70den. Heavier material is available and may be used with final models to aid in the puncture resistance. One side of the nylon is impregnated with a TPU film. The two exposed TPU sides may be heat welded without melting the nylon to create air-tight cushions. Valves can be added and cushions can be designed to fit any need. The trunk section would prove to be more complicated. This section will require some antagonistic actuator sequencing in order to mimic the gait of the larva. It is assumed that cushions would need to be actuated in the top sections along with others in the bottom. This appears to be in equal third lengths of the trunk section. From images of the larva gait, we deduced that the actuators in the middle upper and lower ends would need to be activated in order to mimic the contraction phase (see figure L). Many tests will be needed to understand how to create this movement.
It is proposed that a series of cushions could be pleated and attached to a inextensible fabric base which would act as the straining layer. When filled with air the cushions push against each other and the limiting layer, causing bending. Thus a soft actuator using inextensible materials is formed.
Barndt, L. 2019. Illustration based on information found in Rus. D. and Tolley, M. (2015). Design, fabrication and control of soft robots. Nature, 521(75530, pp.467-475.
Trunk section movement diagrams. Thesis Portfolio: Final Project
Flexible fluidic anisotropic actuator construction diagrams. L. BARNDT 2018 - 2019
FINAL TERM
THESIS REPORT
Flexible Fluidic Anisotropic Actuators for Large Soft Robots Lutz Barndt
University College London - Bartlett School of Architecture
MArch Design for Manufacture: Thesis Submission lutz.barndt.18@ucl.ac.uk
Abstract
This paper explores the application of flexible fluidic anisotropic actuators (FFAA), also known as a pneumatic artificial muscles. Based on smaller fluidic elastic actuators, this study examines FFAAs for use in large soft-robot design. Robots constructed by three-dimensional printing or soft lithography methods focus on silicone in their construction. This study replaces silicone with fabric-based analogies thereby reducing the developed weight of the robot. As computer simulations do not exist to visualise and optimise potential designs, full-scale models are created and tested. The developed FFAA actuators are then applied to a soft-robot design based on the caterpillar larva. The robot will be designed to climb structures with members of 500mm diameters. The potential robot may be used in construction or search and rescue operations.
Keywords
Soft robots / flexible fluidic actuators / thermopolyurethane nylon / bioinspiration
Barndt, L. 2019, Photograph. Model of trunk soft robot.
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
FINAL TERM
THESIS REPORT
Diamond
Steel
Glass
10
11
1012
Enamel
Bone Wood
1010 Nylon
109
Muscle Tendon
Polyethylene
Rubber
108
Skin
Artery
107
106
105 Silicone
SOFT
Fat
HARD
104
Design for Manufacture - Thesis Presentation Conference
Cartilage
Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Barndt, L. 2019. Graphic based on information found in Rus, D. and Tolley, M. (2015). Design, fabrication and control of soft robots. Nature, 521(7553), pp.467-475. A graphic representation of Young’s Moduli of Stiffness. Biological materials are found listed on the right (in units of Pascal).
Barndt, L. 2019, Illustration redrawn from image from https://www.mtwmag. com/industrial-robots-kuka-robotics-india/. An example of a ‘hard’ robot. Barndt, L. 2019, Illustration redrawn from image from https://www.alamy.com/ stock-photo-close-up-view-of-elephant-trunk-with-its-tip-curved-forward-tosmell-12248288.html. An example of a biological robot arm. 30 September 2019 Lutz Barndt
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
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Barndt, L. 2019. Illustrastion based on information found in Rus, D. and Tolley, M. (2015). Design, fabrication and control of soft robots. Nature, 521(7553), pp.467-475. An example of a soft actuator. Fluid or air fill the chambers and cause a deformation in the acturator.
Barndt, L. 2019. Illustration redrawn from Trivedi, D., Rahn, C., Kier, W. and Walker, I. (2008). Soft robotics: Biological inspiration, state of the art, and future research. Applied Bionics and Biomechanics, 5(3), pp.99-117. The diagrams show the differences between hard and soft robots. The hard robot on the left with its stiff linkages compared to the soft robot on the right able to navigate a cluttered environment.
Barndt, L. 2019. Illustration based on a photo found in Tolley, M., Shepherd, R., Mosadegh, B., Galloway, K., Wehner, M., Karpelson, M., Wood, R. and Whitesides, G. (2014). A Resilient, Untethered Soft Robot. Soft Robotics, 1(3), pp.213-223. he silicone robot built with all the necessary components embedded in the system. The robot is 65 centemetres long.
30 September 2019 Lutz Barndt
L. BARNDT 2018 - 2019
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Barndt, L. 2019. Illustration redrawn from Skouras, M., Thomaszewski, B., Kaufmann, P., Garg, A., Bickel, B., Grinspun, E. and Gross, M. (2014). Designing inflatable structures. ACM Transactions on Graphics, 33(4), pp.1-10. Mylar balloon example. The inflated shape developes buckling due to the flat shapes that created it.
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Barndt, L. 2019. Illustration Construction axonometric of an FFAA actuator.
30 September 2019 Lutz Barndt
Thesis Portfolio: Final Project
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Barndt, L. 2019. Illustration based on Trimmer, B., Takesian, A. and Sweet, B. (2006). Caterpillar locomotion: A new model for soft- bodied climbing and burrowing robots. In: 7th International Symposium on Technology and the Mine Problem. Medford, MA USA: Tufts University. Examination of the many parts of the catepillar larva.
Barndt, L. 2019. Illustration Diagram kinematics of the contraction phase of the larva gait.
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Barndt, L. 2019. Illustration Diagram of caterpillar body parts.
Barndt, L. 2019. Illustration Diagram of gripper section deployed on structural column.
30 September 2019 Lutz Barndt
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Design for Manufacture - Thesis Presentation Conference
Basic actuator build up as described above with the changes to the pockets and limiting layer as shown on the left. Results: The actuator has moderate strength. The ratio of air-pocket to limiting-layer can be calculated and perhaps used as an indication of the strength of the actuator. For the amount of TPU nylon used, the actuator is not very effective. Conclusion: Test the shortening of the air pockets while maintaining the limiting layer length. Plan 01
Barndt, L. 2019. Prototype 280/100 Plans
Photo 11 Barndt, L. 2019. Prototype 280/100 unpressurised.
Photo 12 Barndt, L. 2019. Prototype 280/100 0.5kg weight.
Photo 13 Barndt, L. 2019. Prototype 280/100 1.0kg weight.
Photo 14 Barndt, L. 2019. Prototype 280/100 1.5kg weight.
30 September 2019 Lutz Barndt
Thesis Portfolio: Final Project
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Design for Manufacture - Thesis Presentation Conference
Similar actuator build up to prototype 01 with the changes to the pockets and limiting layer as shown on the left. Results: Very weak actuator with very little lift among any of the weight testing. The ratio being half that of prototype 01 proves that the ratio might be a good indicator of the strength of the actuator. This actuator does us less material than 01. Conclusion: Test the shortening of the limiting layer attachment to test strength changes. Plan 02
Barndt, L. 2019. Prototype 140/100 Plans
Photo 21 Barndt, L. 2019. Prototype 140/100 unpressurised.
Photo 22 Barndt, L. 2019. Prototype 140/100 0.5kg weight.
Photo 23 Barndt, L. 2019. Prototype 140/100 1.0kg weight.
Photo 24 Barndt, L. 2019. Prototype 140/100 1.5kg weight.
30 September 2019 Lutz Barndt
L. BARNDT 2018 - 2019
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Plan 03
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Barndt, L. 2019. Prototype 280/50 Plans
Photo 31 Barndt, L. 2019. Prototype 280/50 unpressurised.
Photo 32 Barndt, L. 2019. Prototype 280/50 0.5kg weight.
Similar actuator build up to prototype 01 with the changes to the pockets and limiting layer as shown on the left. Results: Incredibly strong actuator. The ratio is much higher than any of the actuator tested thus far and it appears to prove itself. It is a very small arc or deformation as the limiting layer is so short. This prototype does use a large amount of TPU material. Conclusions: As this is a successful actuator for any need of high strength. The ratio assumption holds out. Next experiment should attempt a ratio between the first two.
Photo 33 Barndt, L. 2019. Prototype 280/50 1.0kg weight.
Photo 34 Barndt, L. 2019. Prototype 280/50 1.5kg weight.
30 September 2019 Lutz Barndt
Thesis Portfolio: Final Project
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Plan 04
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Barndt, L. 2019. Prototype 175/60 Gripper Plans
Photo 41 Barndt, L. 2019. Prototype 175/60 unpressurised.
Photo 42 Barndt, L. 2019. Prototype 175/60 0.5kg weight.
The actuator methodology has been adjusted slightly to improve the tube construction. The heat welded regions between the air pockets has been adjusted to use less material. Limiting material is a white muslin of much heavier strength. Results: Incredible strength, highest results thus far. Using less material than prototype 03 and able to lift 2.5kg (highest tested weight). The ratio seems a bit off, the calculation is only 2.9. Conclusions: This is the structure for the gripper construction. Now the trunk experiments can begin.
Photo 43 Barndt, L. 2019. Prototype 175/60 1.0kg weight.
Photo 44 Barndt, L. 2019. Prototype 175/60 2.5kg weight.
30 September 2019 Lutz Barndt
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BARC00600 Design for Manufacture
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Plan 15
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Barndt, L. 2019. Prototype 140/100 Trunk inflation plans. Photo 51 Barndt, L. 2019. Prototype 140/100 Trunk All sections fully pressurised.
Photo 52 Barndt, L. 2019. Prototype 140/100 Trunk Alternated sections pressurised.
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Thesis Portfolio: Final Project
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Flexible Fluidic Anisotropic Actuators for Large Soft Robots
0
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G1 R0
G1 1 R0/R1/R2/R3
G0
G0/G1 2 R0/R1/R2/R3
Solenoid valves
G0 3 R0/R1/R2/R3
Vacuum pump
4
G0 R0
5
G0/G1 R0
R2 R0 top
Air supply
Exhibit 62 Barndt, L. 2019 Photograph. Arduino code for soft robot control. Pressure sensors Relays Microprocessor
G1 R1 bottom
R3
Exhibit 60 Barndt, L. 2019 Illustration. State diagram of the caterpillar larva soft robot.
Exhibit 61 Barndt, L. 2019 Photograph. Soft robot air supply valve control board. Exhibit 63 Barndt, L. 2019 Photograph. Program debug screen with sensor and state displayed.
30 September 2019 Lutz Barndt
L. BARNDT 2018 - 2019
BARC00600 Design for Manufacture
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THESIS REPORT
Flexible Fluidic Anisotropic Actuators for Large Soft Robots
Design for Manufacture - Thesis Presentation Conference
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Andorf et al. (1976). US Patent: Robot Finger. 3,981,528.
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Gaiser, R., Ivlev, O., Andres, A., Breitwieser, H., Schulz, S. and Bretthauer, G. (2012). Compliant Robotics and Automation with Flexible Fluidic Actuators and Inflatable Structures. Recent Advances and Future Challenges. [online] IntechOpen. Available at: https://www.intechopen. com/books/smart-actuation-and-sensingsystems-recent-advances-and-future-challenges/ compliant-robotics-and-automation-with-flexiblefluidic-actuators-and-inflatable-structures [Accessed 26 Jul. 2019].
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Javanovic, K., Potkonjak, V. and Holland, O. (2014). Dynamic modeling of an anthropomimetic robot in contact tasks. Advance Robotics, (11), pp.793-806. Kier, W. and Smith, K. (1985). Tongues, tentacles and trunks: the biomechanics of movement in muscular-hydrostats. Zoological Journal of the Linnean Society, 83(4), pp.307-324.
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Kim, S., Laschi, C. and Trimmer, B. (2013). Soft robotics: a bioinspired evolution in robotics. Trends in Biotechnology, 31(5), pp.287-294.
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Lexico Dictionaries | English. (2019). Anisotropic | Definition of Anisotropic by Lexico. [online] Available at: https://www.lexico.com/en/definition/ anisotropic [Accessed 19 Aug. 2019].
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Lexico Dictionaries | English. (2019). Compliance | Definition of Compliance by Lexico. [online] Available at: https://www.lexico.com/en/definition/ compliance [Accessed 26 Aug. 2019].
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Lexico Dictionaries | English. (2019). Kinematics | Definition of Kinematics by Lexico. [online] Available at: https://www.lexico.com/en/definition/ kinematics [Accessed 9 Aug. 2019].
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Shepherd, R., Ilievski, F., Choi, W., Morin, S., Stokes, A., Mazzeo, A., Chen, X., Wang, M. and Whitesides, G. (2011). Multigait soft robot. Cambridge: Wyss Institute.
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Fabriclink.com. (2019). Fabriklink - Nylon Fibre Characteristics and Uses. [online] Available at: https://www.fabriclink.com/University/Nylon.cfm [Accessed 26 Oct. 2018].
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Shepherd, R., Ilievski, F., Choi, W., Morin, S., Stokes, A., Mazzeo, A., Chen, X., Wang, M. and Whitesides, G. (2011). Multigait soft robot. Proceedings of the National Academy of Sciences, 108(51), pp.20400-20403.
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Skouras, M., Thomaszewski, B., Kaufmann, P., Garg, A., Bickel, B., Grinspun, E. and Gross, M. (2014). Designing inflatable structures. ACM Transactions on Graphics, 33(4), pp.1-10.
Perfectex.com. (2019). Perfectex - TPU, Hot Melt Adhisive Film/Sheet/Tape, Ether, Ester, TPU Foam, TPO, Neoprene, Webbing. [online] Available at: http://perfectex.com/tpu_ thermoplasticpolyurethane.html [Accessed 26 Nov. 2018].
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Tellez, R., Ferro, F. and Garcia, S. (2008). Reem-B: an autonomous lightweight human-size humanoid robot. Daejeon: IEEE-RAS.
the Guardian. (2019). Japanese researchers build robotic tail â&#x20AC;&#x201C; video. [online] Available at: https:// www.theguardian.com/world/video/2019/aug/15/ japanese-researchers-build-robotic-tail-video [Accessed 27 Sep. 2019].
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Terry, J. (2018). Adaptive Control for Inflatable Soft Robotic Manipulators with Unknown Payloads. All Theses and Dissertations. Brigham Young University.
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Marchese, A., Katzschmann, R. and Rus, D. (2014). Whole arm planning for a soft and highly compliant 2D robotic manipulator. In: 2014 IEEE/ RSJ International Conference on Intelligent Robots and Systems. IEEE.
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Mori, Y. and Igarashi, T. (2007). Plushie. ACM Transactions on Graphics, 26(99), p.45.
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Nemiroski, A., Shevchenko, Y., Stokes, A., Unal, B., Ainla, A., Albert, S., Compton, G., MacDonald, E., Schwab, Y., Zellhofer, C. and Whitesides, G. (2017). Arthrobots. Soft Robotics, 4(3), pp.183190.
Tolley, M., Shepherd, R., Mosadegh, B., Galloway, K., Wehner, M., Karpelson, M., Wood, R. and Whitesides, G. (2014). A Resilient, Untethered Soft Robot. Soft Robotics, 1(3), pp.213-223.
24.
Ou, J., Skouras, M., Vlavianos, N., Heibeck, F., Cheng, C., Peters, J. and Ishii, H. (2016). aeroMorph - Heat-sealing Inflatable Shapechange Materials for Interaction Design. Tokyo: UIST.
Trimmer, B., Takesian, A. and Sweet, B. (2006). Caterpillar locomotion: A new model for softbodied climbing and burrowing robots. In: 7th International Symposium on Technology and the Mine Problem. Medford, MA USA: Tufts University.
25.
Trivedi, D., Rahn, C., Kier, W. and Walker, I. (2008). Soft robotics: Biological inspiration, state of the art, and future research. Applied Bionics and Biomechanics, 5(3), pp.99-117.
16.
17.
Rus, D. and Tolley, M. (2015). Design, fabrication and control of soft robots. Nature, 521(7553), pp.467-475.
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Thesis Portfolio: Final Project
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Sketch ideas for the construction of the valve box to control the air within the soft robot system. Electronics and air lines are combined to create a bespoke systems control. L. BARNDT 2018 - 2019
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Diagrams of the circuit board constructions. The larger board displays the distribution of the signals from the microprocessor through the Darlington arrays and then groups the paths to the relays and the display lights. The smaller board shows the layout of the pressure sensors with the associated signal distributions and power inputs.
Final outcome of the pressure sensors attached to their circuit board. The boards were created then installed on the valve box and wired into the control system.
Line drawing of the valve box.
Rendered view of the valve box computer model showing the relays, microprocessor and the air supply locations. Thesis Portfolio: Final Project
Rendered view of the valve box computer model showing the relays, microprocessor and the air supply locations.
Rendered view of the valve box computer model showing the valve positions and the connectors used to distribute the air to the sensors. L. BARNDT 2018 - 2019
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Pressure sensor
Air exhaust Valve
Valve Air intake
Supply to robot
Schematic diagram for the solenoid valve layout.
The valve box was designed to minimise the size required for the solenoid valves. The valves were placed in line to enable the box to separate the different air lines and provide supply and pressure release as necessary. L. BARNDT 2018 - 2019
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Image of the final valve box showing the relays and microprocessor. Thesis Portfolio: Final Project
The actual valve box showing the valve solenoids leading to an arrangement of connector valves which direct the air through the sensor and lead to the final air cushion. The circuit boards shown at the top contain the pressure sensors which feed the information back to the microprocessor. L. BARNDT 2018 - 2019
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The plans above show the final construction for the current soft robot. Many alternatives were investigated. The best means for testing was full real models, which made for slow progress. The solid grey areas denote the limiting layer used by the actuators to create their movement. The trunk plans show the orchestration of the valves. L. BARNDT 2018 - 2019
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The screen capture of the debug screen is shown above. It displays all the information the code is using to choreograph the inflation of the soft robot The numbered diagrams shown above display the states of the soft robot. The state diagram is then interpreted into code which the microprocessor uses to coordinate the air cushions. movement â&#x20AC;&#x2DC;gaitâ&#x20AC;&#x2122; of the soft robot. The diagram above organises the robot into sections which the code interprets and signals as the state requires. Thesis Portfolio: Final Project
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FINAL ROBOT EXECUTION Challenges of soft robots The development of soft robots face many challenges. The lack of rapid design tools for visualising is one. While some software has been developed for the fashion industry and other reports have advanced fabric visualisation [14][20]. Unfortunately, there are many other factors involved in the design of soft robots that computers have not been able to render. Perhaps only certain aspects of soft robot design may be visualised before making physical models. In addition to visualisation, advancements are needed in the approaches to control the soft robot. If a robot is controlled by pneumatics, one must consider the control of air to the system. The proper amount, the rate of inflation or deflation, the pressure the air is delivered are some of the factors that enter into the soft robot control equation. Compressed air is a challenging medium. The sensors used to read the pressure in a soft robot system fluctuate and the values can be scattered. This leads to errant understanding to the robot position and can lead to inaccuracies. As a result, the kinematics of a soft robot may be considered a â&#x20AC;&#x153;dark artâ&#x20AC;? compared to the straight-forward calculations achieved by the hard robot. One way of improving the designs of soft robots are to allow access to more non-experts. The designs will change as people experiment and there will be more acceptance of soft robots if everyone is more familiar with them. Programmable Air is an example of open source resources for the study of soft robots. It offers pneumatic controls, computer programs and control boards. Sensors, actuators, processing power, etc. are key features of a soft robot. The unification of these elements in soft robot design creates two things. The soft robot will become an embedded system, all the functions the robot requires, can be carried by itself. This will lead to a selfsustaining system that will only require a recharge. The other aspect that will be developed from embedded systems are smart materials.
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FINAL ROBOT EXECUTION As a soft robot is limited in size and weight, designs must develop multi-functioning systems that can integrate the sensors, actuators, computation, power storage and communication within the materials of the robot. An example of this can be found in the soft robots that are formed by three-dimensional printing or soft lithography. Their bodies integrate channels for air distribution, or voids for embedding mechanics. By creating more functions from the components of robot design, automated machines will be able to accomplish more with less. Soft robot design has been able to explore the characteristics of automation that the hard robot has not. They are able to look to biological analogies and apply them successfully to create unique automated solutions. The soft robot is compliant and can safely work alongside humans. They can function in cluttered environments and adapt. This allows them to work in hazardous locations, they may be used for search and rescue, construction investigation, or underwater. They may also be utilised in the medical field. While the study of soft robots maybe young, it is a potent area of research for the advancement of automation. Characteristics of Flexible Fluidic Anisotropic Actuators As we have seen with other actuators, the materials used in their manufacture impart their characteristics unto them. Since the FFAAs are made of air and fabric, they are entirely compliant. This allows them to be used in proximity of operators without the need for safety zones. The pneumatic actuation of the FFAAs creates a method of control that utilises air. As air is universally available, the operation of FFAA actuators is inexpensive. Air can be efficiently transferred using tubes and valves. The control speed depends upon the amount and rate of the supplied air. If FFAAs are deployed in a soft robot, it would be also have infinite degrees of freedom allowing the design to be unrestricted in movements. The mechanics could become embedded in the robot as seen in the large silicone robot. However, small compressors might be less effective for the scale intended. Most likely, a base unit with the compressor, valves and processing will be employed. Simple air lines will tether the potential robot. A robot created with FFAAs would appear to be a simple machine. However, despite the use of less complex actuators, complicated gaits can still be achieved as seen in the robot in figure G. As the robot is avoiding the use of silicone, the parts may be manufactured less expensively.
However, nylon is poor in resistance to continuous exposure to sunlight. The characteristics imparted by the TPU are similar. TPU has good flame resistance, strong antimicrobial fibre, fluid resistant and easy to clean. Similar to nylon, TPU resist abrasion, and cracks over a range of temperatures. TPU has high strength and low shrinkage. It resists oil and lubricants and stands up well to oxidation and aging. As both materials have good abrasion resistance, the soft robots created by them would prosper in harsh or unstructured environments. Both materials are used in shoes, garments and medical supplies. Nylon impregnated with TPU is often used for the construction of raft and airships. Soft robots made of TPU nylon materials have their limitations. Firstly, compressors are usually loud and heavy. And the argument might be made concerning the thermodynamic inefficiencies of moving large volumes of air. Weight will be a concern when enlarging an actuator, however, using fabric and air may mitigate them. As any bicyclist will attest, the problem with cushions are sharp objects. Additional protections may be made to protect the design including ballistic fabrics. As with the McKribben type actuators, the constant use and strain on the material will cause wear. Actuators may need replacements and that can be accommodated in their design. As with soft robots, the actuators are limited in their accuracy. They are electromechanically challenged. The sensing and controlling of the actuators are difficult and the softness leads to errors already discussed. The movements must be designed with tolerances built into them.
It is the hope of this report that the developed flexible fluidic anisotropic actuators may be utilised for future robots. Some automation can be introduced in the manufacture of the actuators. A CNC table can be created to build the TPU air pockets as can be seen in the aeroMorph studyOu, J., Skouras, M., Vlavianos, N., Heibeck, F., Cheng, C., Peters, J. and Ishii, H. (2016). aeroMorph - Heat-sealing Inflatable Shape-change Materials for Interaction Design. Tokyo: UIST. The CNC table can heat seal and cut the TPU onto any material. The resulting robots can be used to create structures for more complex operations. Perhaps an additional arm can be strapped to a construction worker and allow them additional support as they build. With the inherent compliance of the trunk, operation of the robot would not impose any additional risk to their work environment. Some studies have been observed that propose a trunk-like tail attachments to aid in the balance of the elderly. The field of soft robots does offer many opportunities for design and manufacture. It will be exciting to continue to observe the advances.
The TPU and nylon qualities are also transferred to the new robot. The nylon is strong and lightweight. Nylon has good abrasion resistance and low moisture absorbency. It is available in a range of colours.
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The Development of Flexible Fluidic Anisotropic Actuators for Large Soft Robots
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