The Tube-Crawler



The Tube-Crawler

Final Report

by

Matthew Dombach

AJ Schrauth

Dan Parent

ME-43

December 19, 2002

Table of Contents

Summary.............................Page 2

Objectives............................Page 2

Specifications..........................Page 2

Solution

Naming ..........................Page 3

Operational Attachment..............Page 4

Anchor Rings ......................Page 5

Extension Section...................Page 7

Tether...........................Page 9

Exterior Assembly...................Page 10

Test Apparatus.....................Page 11

Analysis...............................Page 12

Budget................................Page 15

Team Responsibilities.....................Page 15

References.............................Page 16

Parts List..............................Page 17

Summary

The initial task, as stated in the previously submitted Design Proposal, was to design a robot to crawl through tubes of various parameters. This task was accomplished by relying heavily on inflatable balloons, which are used to secure the robot against the walls of the tube, as well as propel the robot forwards and backwards inside of the tube. This has proven to be a reliable solution to the problem, as our performance specifications have been matched. The tube-crawler successfully traverses a tubing arrangement of varying diameter and direction.

Objectives

The overall goal of this project was to create a robot that is capable of traversing the interior of a tube or pipe of varying arrangement.

Specifications

The following guidelines, which are taken directly from the previously submitted Design Proposal, were the governing criteria for the design of the robot:

• The tubes that will be traversed must be rigid in construction, of varying diameter between six and eight centimeters, arranged in either straight sections or forty-five degree elbows, and not limited in material, although a transparent material is preferred.

• The robot must traverse a path consisting of a variable arrangement of an unknown number and orientation of straight sections and forty-five degree elbows of tube with repeatability greater than seventy-five percent success rate, which entails traveling through the tube arrangement without error.

• The robot should be constructed such that the design can be adapted and rebuilt at a different scale (most likely smaller), such that the design can be adapted to a plethora of applications. One such application where a scaled-down model is necessary is colonoscopy, which has been kept in mind during the design of several components of the robot.

Solution

Naming

Before we begin describing our solution, it is necessary to restate the naming scheme that was used, such that a description of parts and procedure is more meaningful. The image below shows the adopted naming scheme:

[pic]

Operational Attachment

The operational attachment is on the leading end of the tube-crawler. Its purpose is to contain any of the accessories necessary for functionality of the tube-crawler in various applications. For this current iteration, the operational attachment will contain a camera, including a fish-eye lens (see parts list) for optimal viewing inside of a tube, and super-bright LEDs to illuminate the interior of the tube. One important property of the operational attachment is that it is fully detachable and replaceable. This is true because most of the wires from the USB cable that attaches the camera to a computer can disconnect from the CCD board of the camera; however, the ground lead did not detach as such, so it was necessary to wire a quick disconnect socket into the board for the ground lead.

[pic]

The outer casing of the operational attachment is constructed of a plastic acorn capsule, 2 inches (about 5 centimeters) in diameter. It snaps into a ring constructed of a more flexible plastic, which was cut from the cap of the acorn capsule, and glued to the top of one half of the leading anchor ring. A roughly 2 centimeter hole must be cut out of the acorn capsule before assembly, such that the lens threads will fit through but the head of the lens will barely touch; an Exact-O Knife is perfect for this task. The camera sits inside of the acorn capsule, glued in place with hot glue, and the lens screws into the lens mount of the camera via standard 12mm x 0.5mm threads. The USB cable from the camera, along with the encased electronics on the wires, fold into the space inside of the acorn capsule between the camera itself and the leading anchor ring. This leaves space for the nylon fittings used to stop the flow of air into the extension chamber inflatable bladders. Below is a drawing of the operational attachment.

Anchor Rings

The design of the anchor rings has been detailed in the previously submitted AutoCAD files and is displayed in the appendices (robotics_interim_anchor and robotics_interim_anchor2). A total of four anchor rings were produced, 2 for the working model and 2 for a demonstration model, and each has been machined from aluminum. There is one minor modification to these original drawings: the flange around the interior bore has been machined down flush to the interior shelf of the inside face of the anchor rings. This was done to create clearance for the hex nuts on the nylon fittings that attach to the 160Q balloons to the anchor rings.

The anchor rings are composed of two sections, fastened together with four set screws. These two sections create a clamping structure which pinches the balloons in place. The balloons are wrapped around the air tubes that run from the valves, and are clamped together using a silicone spacer. This spacer is a short cylinder with a c-shaped cross section, so that it can act as both a cushion to create an air-tight seal with the air tube, and a clamp that secures the anchor balloon around the anchor ring. The balloon is stretched halfway around the anchor ring, and pinched by the silicon spacer of the opposing section. The image below shows one half of the anchor ring; notice how the balloons are attached to the silicone spacers.

[pic]

The anchor balloons, along with the extension balloons, should be replaced before each use of the robot. This is important because the balloons, once inflated, tend to bunch up on themselves when deflated. If they are left bunched up for an extended period of time, they stick to each other, and subsequently inflating the balloons leads to leaks and ruptures. An initial solution to this problem was to coat the insides of the balloon with talcum powder to prevent adhesion. However, this solution cannot be applied to the exterior of the balloons because the powder would reduce grip on the interior of the tube.

Another cause of the rupture of the anchor balloons is the dragging of the balloons on the tube when the anchor rings sag with respect to each other. This dragging caused the balloons to twist on themselves, creating a similar problem to that described above. To counteract this, several knobs were attached to the anchor rings. These knobs are constructed out of the ends of the 4" LG Low Profile Plastic Zip Ties, as shown in the image below in the red circle. Additionally, these knobs reduce the magnitude of the friction force preventing the motion of the anchor ring along the tube, in the case of sag.

[pic]

The four steering cables are threaded through the 1/16” holes of the anchor rings. This diameter was chosen so that the outer casing of the steering cables could just barely fit inside of these holes; the outer casing is size 22 Standard Wall PTFE (Teflon) tubing, which has an outer diameter of 0.054 inches, just smaller than 1/16” (0.0625 inches). This allows an increased surface area interaction to glue the casing to the following anchor ring. The holes are drilled into the anchor ring at ninety-degree angles with respect to each other in order to allow the tube-crawler a wide range of motion. The fishing line runs through the following anchor ring to the leading anchor ring and is glued and clamped in place at the front end of the leading anchor ring.

Extension Section

The extension section is the main source of propulsion for the tube-crawler. It is comprised of several components that allow the tube-crawler to extent, retract, and navigate through the tube. The extension section is extended by the inflation of bladders, retracted by the deflation of the bladders and springs, and navigated by steering cables. The diagram below shows where each is attached:

The inflatable bladders are constructed by cutting a one and a half inch section out of a Qualtex 160Q balloon. The balloon is then wrapped around a nylon fitting on each end, such that the barbs point towards the inside of the balloon and the threads point outwards. The balloon should wrap around the hex nut section of the fitting, so that when the nut is tightened, it clamps the balloon between the flush surface of the anchor rings and the fitting. The illustration below shows the construction of the extension section balloons. Four such bladders must be constructed, although we have fabricated extra bladders in case of rupture.

[pic] [pic]

The four tension springs are glued into place around each of the steering cables. The purpose of these springs is to return the extension section to its un-stretched length. Ideally, the springs should have an un-stretched length of one half inch, and extend to around three inches. Though it may not actually be necessary, the springs must be strong enough to retract the extension section at the most critical orientation of the tube-crawler, traveling vertically upwards. In such a case, the springs act against the weight of the following anchor ring, the valves, and the tether dragging behind it.

To finish off the extension section, a fabric sheath was constructed from a generic cotton stock. This sheath is five centimeters in diameter, and three and a half inches long. It fits snugly over the leading and following anchor rings (overlapping roughly one quarter of an inch on each end), and is secured in place using one 7” LG Low Profile Plastic Zip Tie on each end.

Tether

The tether that runs from the external assembly to the tube-crawler contains several wires and hoses. It is two meters long, which allows for the tube-crawler to traverse a tube of up to a meter and a half deep. The core of the tether is a 22 gauge galvanized wire that attaches to the leading anchor ring, such that the tether is pulled by the inflation of the bladders in the extension section instead of the springs. The largest wire is the USB cable for the camera, which is roughly one quarter of an inch in diameter. Also included in the tether are: the main air hose, one eighth of an inch inner diameter, which supplies pressure to the valves; the control leads for the three valves; and the four steering cables. All of these wire and hoses are bundled together and encased inside one-inch un-shrunk diameter heat shrink tubing. Altogether, the tether is no greater than three quarters of an inch in diameter.

Also attached to the tether are the valves that control the inflation and deflation of the balloons. There are three Asco Miniature Solenoid valves, which are configured to be normally closed. When the valve is energized, air is allowed to flow from the main air tube to the attached balloons. When de-energized, the valves allow air to escape from the balloons, which is exhausted directly from the valves. This is elucidated by the diagram below:

[pic]

Exterior Assembly

The External Assembly performs three main functions for the robot. It supplies the compressed air to the balloons. It pulls and releases the steering cables to control the robot. Finally, it provides all control signals to the robot.

The pressurized air supply is a pretty straightforward system. It currently uses a lab air pressure line to as its source, but the final version will use a compressed air tank. Using a tank solves the portability problem and it does not generate extra noise like a portable air compressor would. We purchased a high precision regulator and a standard air filter to properly condition the compressed air supply.

In order to steer the robot we decided to use a cable system much like the ones used to control bicycle derailleurs and brakes. Bicycle brake cables, however, are much too large for our application, so we used fishing line inside of wire insulation instead. In order to control the robots’ direction, we arranged four cables radially around the center of the extension section. When one of the cables is tighter than the others and the robot extends, it turns in the direction of the tightest cable. The external assembly must be able to pull each cable to a specific location and supply enough force to hold each cable in place during the extension part of the cycle. Stepper motors provided the optimal degree of position resolution without the need for a complex feedback control system. The only problem with stepper motors is that they don’t generate a large amount of torque. The attached calculations under Stepper Motor Calculations show the torque required for one stepper motor to pull against the full extension force is 76.1 oz.-in. given that we use 5/8” DIA pulleys on the stepper motors. The stepper motors we selected, Applied Motion Products: HT23-397, have a holding torque of about 177 oz.-in; more than enough to do the job.

The motors will be mounted to an aluminum mount plate (see Stepper Motor Mount Plate in the appendices) to help dissipate any heat they generate during operation. The plates will be mounted to 3-1/2” x 4” x 3/4" pine blocks. The steering cable casing must be secured to the frame of the frame of the external assembly so that the motors can move the cable relative to the frame. To do this we secured a thin (1/4” thick) piece of wood to one side of each aluminum mount plate and screwed a small eyehook into the wood near each stepper motor. We then glued the cable casing to each eyehook and ran the cable through the casing.

The electronics that allowed the control of the stepper motor and valve were constructed to our specifications by the electrical/computer engineers assisting us on this project. They encoded a logic circuit onto several PIC controllers that are connected to each of the stepper motors and each of the valves. The logic circuits are shown below.

Stepper Motors:

[pic]

[pic]

[pic]

Valves:

[pic]

An alternate valve circuit was also constructed, which allows manual operation.

Test Apparatus

Although our specifications called for 6-centimeter to 8-centimeter diameter PVC tubing, we had to make some modifications based on what is actually available and economically sound. First of all, clear PVC tubing is entirely too expensive, especially for fittings, so we chose to use opaque (white) PVC tubing for the elbows and couplings. Furthermore, clear PVC tubing greater than an inch and a half in diameter quickly doubles and triples in price, thus we chose to use clear acrylic tubing. Also, we found it very difficult to locate metric tube sizes, and even when found, 6- and 8-centimeter diameters were nowhere to be found. Thus, we decided on 3-inch and 4-inch clear acrylic tubing, which have inside diameters of 2.75” and 3.75” respectively. This translates to 7-centimeter and 9.5-centimeter inside diameters, respectively. These should both be sufficient to demonstrate the tube-crawler.

The actual arrangement of the test apparatus is insignificant. It will demonstrate that the tube-crawler can traverse any arrangement of tubing, including 45-degree elbows and reducing couplings, with ease. Thus, the arrangement of the test apparatus will be random for any demonstration.

Analysis

The key factor to the performance of the tube-crawler is the reliability of the inflatable bladders. Several tests were run to check the reliability of the Qualtex 160Q balloons. The first general finding was that the balloons needed to be inflated and deflated several times before they perform predictably. Thus, upon installation of a new balloon, it must be inflated and deflated several times before the tube-crawler can perform reliably. Furthermore, the anchor section balloons must be stretched across the anchor ring, inflated, and re-stretched across the anchor ring again at least once. This insures that the anchor balloons inflate a minimum amount away from the anchor ring.

One test that was run examined the operating pressure of the system such that the balloons would inflate and deflate reliably. We attached the compressed air line from the TUFTL laboratory to the Precision Regulator and the Air Filter, then attached tubing to one of the 160Q balloons. It was found that a pressure of between 4 and 5 psi is optimal, although it took a slightly higher pressure to inflate each balloon for the first time. Again, this will not be an issue since the balloons will be inflated and deflated several times before they are installed in the tube-crawler. Another test that was run sought to find the pressure at which the 160Q balloons would rupture. We found that the balloon ruptured at just less than 6 psi, accompanied by a deafening “pop”. However, as long as the balloons are broken in beforehand and the fittings are attached carefully, we should be able to operate successfully at 4 psi.

As we were constructing the robot we periodically tested individual components. One such component was the anchor balloons. Once the anchor rings were machined balloons we immediately attached the anchor balloons to evaluate their performance. This test was conducted by inflating the anchor balloons on the anchor ring while inside of a tube. This demonstrated both the proper functioning of the anchor ring and the holding capacity of the balloons. We found that our results were congruent with our calculation of maximum holding capability as seen in the Anchor Stability Calculations found in the appendices. One interesting result from this test was that the anchor balloons did not inflate evenly unless the anchor ring was held in the center of the tube. This was anticipated as problem when the robot travels through horizontal tubes. The robot would be lower on the side of gravity and not inflate fully on that side. To counter this, knobs were attached circumferentially around the anchor rings to keep the robot from resting on one side or the other.

Once we were content with the performance of the anchor rings, we attached the anchors together with the extension balloons and springs. The expansion of the extension balloons was then tested with only the existing components. We found that the average step size inside of the tube was approximately one and a half inches. This is an acceptable step length and continued with the current design.

Unfortunately once the other sections were attached we found that our step size had substantially decreased. The previous step leads us to believe that this is not due to either a lack of expansion in the balloons or too stiff of springs. Thus we were forced to evaluate the factors that limit step sizes previously achieved. Possibilities include high friction of USB cord through rear anchor ring, and friction of steering cables inside of their casing. An attempted solution to eliminate the high friction of the USB cord was to encase the USB cord in a low friction tube. This tube would remain immobile inside of the center hole of the anchor ring and would serve as a boundary separating the USB cable from all of the other tubes. This low friction tube had to be able to fit over the end of the USB cable yet be small enough to not take up a large amount of space in the interior hole of the anchor ring. The best solution to this was heat shrink tubing. This tubing could easily fit over the ends of the USB cord, and be shrunk to take up less space. The FP-301 heat shrink tube that we found also had a very low coefficient of friction.

To combat the friction inside of the steering cable casing, we incorporated a smaller diameter fishing line. Originally thirty pound fishing line was used to have a large factor of safety and because it was readily available. The diameter of the thirty pound fishing line was just under the inner diameter of the steering cable casing causing a large contact surface for the friction to act. We decided to eliminate this unnecessary factor of safety by using twenty pound fishing line. With this new type of fishing line we decreased our diameter by three hundredths while maintaining a safety factor of four.

Another minor issue that approached us once testing the completely assembled robot was buckling of the steering cables inside of the springs. The fishing line of the steering cables would not slide back into the casing when the extension section compacted. As the springs contracted, they forced the fishing line to buckle, which then caused the springs to buckle. This had a net effect that prevented the two anchor rings from coming together due to the incomplete contraction of the springs. The idea of using a smaller diameter fishing line acted as a solution again, as it allowed the steering cable to more easily enter the steering cable casing. The decreased diameter had an increased side effect incase there was still buckling. Since the fishing line’s diameter was less, it could fold in a smaller diameter then the original fishing line. This basically translates into the fact that if the twenty pound fishing line ever does buckle, it will buckle inside of the diameter of the spring, allowing the spring to contract naturally and not buckle.

The original goal of this project was to design and construct a robot that can traverse a tube of varying parameters. We were successful in designing and constructing a robot that is capable of traveling through a straight tube with repeatable performance. Unfortunately, the steering capability of the robot was never achieved. As we addressed other issues, we decided that the importance of steering the robot paled in comparison to the importance of mastering locomotion, since once locomotion is mastered, attaching the steering system is easily accomplished.

|Budget |

|Category |Budgeted |Spent |Difference |

|Valves |$300.00 |$365.45 |($65.45) |

|Motors |$600.00 |$358.10 |$241.90 |

|Air Pump |$100.00 |$39.99 |$60.01 |

|Camera |$1,000.00 |$260.00 |$740.00 |

|Inflatable Components |$600.00 |$59.76 |$540.24 |

|Electronics |$1,000.00 |$626.64 |$373.36 |

|Misc. Hardware |$100.00 |$380.85 |($280.85) |

|Totals |$3,700.00 |$2,090.79 |$1,609.21 |

| | | | |

|Available: |$5,000.00 | | |

|Remaining: |$2,909.21 | | |

Team Responsibilities

As outlined in the original design proposal, each team member was assigned several key tasks to perform. There have been no changes to this arrangement throughout this project, although it should be noted that all team members put in an equal amount of time throughout the construction and testing process.

References

Books

Fox, Robert W. Introduction to Fluid Mechanics. John Wiley and Sons Inc.: New York. 1992.

Hamrock, Bernard J. Fundamentals of Machine Elements. WCB McGraw-Hill: Boston. 1999.

Rex, Douglas K. Flexible Sigmoidoscopy. Blackwell Science: New York. 1996.

We were fortunate enough to be affiliated with several individuals that aided us in the design process:

Prof. Caroline Cao – Project Advisor

Prof. Cao provided us with background information concerning colonoscopy and desired capabilities of a tube-crawling robot.

Prof. Douglas Matson – Project Advisor

Prof. Matson aided us in brainstorming potential design specifications, most

importantly helping us make the transition from ideas to a tangible product.

Prof. Chris Rogers – Project Advisor

Prof. Rogers made sure we were heading in the right direction at the very

beginning of the project, and helped us acquire the camera that we are using in the current iteration of the project.

Prof. Steve Morrision

Prof. Morrision helped us greatly in the design of the electronic portions of the

project, such as the circuits to control the valves and stepper motors.

Prof. James O’Leary

Prof. O’Leary was a helpful resource in reference to the acquisition of machine components of the robot.

Adam Wilson, Jason Adrian

Electrical/Computer Engineers who constructed the electrical components for the stepper motors and valves.

Dave Cades, Eric Basford

Human Factors majors who informed us about the current technologies in colonoscopy.

Diana DeLuca, Laura Hacker

Child Development majors who provided a helpful perspective on how to use this robot as a teaching tool.

|Part Description |Manufacturer/Supplier |Part Number |Number Required |Cost |

|  |  |  |  |  |

|Operational Attachment |  |  |  |  |

|USB Camera |Lego |9731 |1 |$49.99 |

|Fish-eye camera lens |Omnitech Robotics |ORIFL 190-3 |1 |$260.00 |

|Super Bright LEDs |Jameco |  |2 |$2.95 |

|2" Acorn Capsule |Brooks Pharmacy |  |1 |$0.25 |

|  |  |  |  |  |

|Anchor Sections |  |  |  |  |

|Anchor Ring |Machined Aluminum |  |2 |  |

|160Q Balloons |Qualtex |  |4 |$4.20 /144 |

|1/8" ID Tubing |McMaster-Carr |51135K166 |5' |$0.53 /ft |

|  |  |  |  |  |

|Extension Section |  |  |  |  |

|160Q Balloons |Qualtex |  |1 |$4.20 /144 |

|5 cm DIA fabric sheath |Handmade |  |1 |  |

|1 cm DIA fabric sheath |Handmade |  |4 |  |

|7/16" x 2-3/4" x .034" Extension Spring |Home Depot |SP-9612 |4 |$2.52 |

|7" LG Low Profile Plastic Zip Ties |Home Depot |SF175-50C |2 |$7.45 /100 |

|4" LG Low Profile Plastic Zip Ties |Home Depot |SF100-18BC |2 |$4.96 /100 |

|FDA Nylon Single Barbed Tube Fitting Barb X Male |McMaster-Carr |5116K201 |16 |$1.61 /10 |

|For 1/16" Tube ID, 10-32" Unf | | | | |

|  |  |  |  |  |

|Tether |  |  |  |  |

|1/16" ID tubing |McMaster-Carr |51135K115 |4m |$0.33 /ft |

|1/16" tube splitters |McMaster-Carr |5116K201 |5 |$1.61 |

|fishing line |Decathalon Sports |55866 |8m |$1.88 |

|Teflon Wire Insulation |Markel |  |8m |$100/1000ft |

|PVC Color-Coded Heat-Shrink Tubing 1" Expanded ID, |McMaster-Carr |7132K444 |2m |$41.30 /50' |

|1/2" Shrunken ID, 50' L, Clear | | | | |

|22-Gauge Galvanized Wire |Home Depot |50135 |2m |$1.99 /100' |

|KIP-Norgren Normally Closed. 12VDC Series 9, 3-way |MSC Industrial Supply |7420987 |3 |$27.74 |

|brass | | | | |

|1/8" ID tubing |McMaster-Carr |51135K166 |2m |$0.53 /ft |

|  |  |  |  |  |

|External Section |  |  |  |  |

|NEMA size 23 High Torque Stepper Motor |Applied Motion Products |AMP23HT-349 |4 |$84.00 |

|Stepper Motor Mount Plate |Machined Aluminum |  |2 |  |

|8-32 x 1-1/4 LG Flat Head Bolts |Home Depot |28451 |16 |$0.79 /6 |

|8-32 nuts |Home Depot |28451 |16 |$0.79 /6 |

|#10 Standard Washers |Home Depot |19811 |48 |$0.79 /30 |

|#8 x 1-1/2" LG Flat Head Wood Screws |Home Depot |21092 |4 |$3.57 /100 |

|4 x 3-1/2 x 3/4 Pine Spacer Blocks |Home Depot |  |2 |$2.40 /6' |

|6 x 1-1/2 x 1/4 Aspen Cable Guide Mount |Home Depot |  |2 |$0.94 /4' |

|#216-1/2 Screw Eye |Home Depot |14271 |8 |$0.79 /8 |

|Zinc Body Precision Regulator 3/8" Pipe, 14 Scfm |McMaster-Carr |6162K29 |1 |$67.44 |

|Max, 2 To 25 Psi Range | | | | |

|Filter With Zinc Body and Bowl Manual Drain, 3/8" |McMaster-Carr |4958K35 |1 |$35.40 |

|Pipe, 90 Scfm Max | | | | |

|Industrial Shape Pneumatic Hose Coupling Plug, 3/8"|McMaster-Carr |6534K47 |2 |$1.03 |

|NPT Male Hose Connection, 1/4" Coupler | | | | |

|Brass Pipe Nipple Schedule 40 3/8" Pipe Size X |McMaster-Carr |4568K152 |4 |$0.88 |

|1-1/2" Length | | | | |

|Brass Threaded Pipe Fitting - 125 Psi 3/8" Pipe |McMaster-Carr |4429K162 |2 |$2.77 |

|Size, 90 Degree Elbow | | | | |

|Brass Threaded Pipe Fitting - 125 Psi 3/8" Female X|McMaster-Carr |4429K732 |4 |$2.77 |

|1/4" Female Pipe, Reducer Coupling | | | | |

|Precision Miniature Aluminum Hub Drive Roller 55 |McMaster-Carr |2481K12 |4 |$22.02 |

|Durometer, 5/8" Diameter, 3/8" Width, 1/4" Bore | | | | |

|FDA Nylon Single Barbed Tube Fitting Barb X Male |McMaster-Carr |5116K85 |1 |$1.68 /10 |

|For 1/8" Tube ID, 1/4" NPT | | | | |

|  |  |  |  |  |

|Test Apparatus |  |  |  |  |

|Extruded Acrylic - Hollow Rod 3" OD, 2-3/4" ID, 6' |McMaster-Carr |8532K23 |6' |$21.53 |

|LG | | | | |

|Clear Cast Acrylic - Hollow Rod 4" OD X 3-3/4" ID, |McMaster-Carr |8486K378 |3' |$43.53 |

|3' LG | | | | |

|Gravity-Flow Sewer & Drain Pipe Fitting-White 3" |McMaster-Carr |9102K133 |4 |$1.38 |

|Pipe Size, 45 Deg Elbow, Socket | | | | |

|Gravity-Flow Sewer & Drain Pipe Fitting-White 4" |McMaster-Carr |9102K134 |4 |$1.18 |

|Pipe Size, 45 Deg Elbow, Socket | | | | |

|Gravity-Flow Sewer & Drain Pipe Fitting-White 4" X |McMaster-Carr |9102K243 |2 |$1.41 |

|3" Pipe Size, Reducing Coupling, Socket | | | | |

Appendices

Other Researched Robotic Designs:

[pic]

1ft diameter tube crawler

Appendices

Other Researched Robotic Designs:

[pic]

Peristalses Robot

Appendices

Other Researched Robotic Designs:

[pic]

Linkage Extension Design

Appendices

[pic]

Spring Buckling

[pic]

Close Up of Spring Buckling

Appendices

[pic]

Screenshot of Camera View

[pic]

LabView Code Used by Camera

Appendices

[pic]

AutoCad of Anchor Rings

Appendices

[pic]

AutoCad of Motor Mount

Appendices

[pic]

Rendered AutoCad of Robot

Appendices

Stepper Motor Calculations

[pic]

Appendices

Maximum Thickness Calculations

[pic]

Appendices

Maximum Thickness Calculations continued

[pic]

Appendices

Spring Coefficient Calculations

[pic]

Appendices

Spring Coefficient Calculations continued

[pic]

Appendices

Pressure Loss Due to Friction Calculations

[pic]

Appendices

Anchor Balloon Stability Calculations

[pic]

Appendices

Anchor Balloon Stability Calculations continued

[pic]

Appendices

[pic]

AutoCad of Valves

[pic]

Picture of Valves

Appendices

[pic]

Side View of Robot

[pic]

Side Schismatic of Robot

Appendices

[pic]

Close up of Camera and CCD Board

[pic]

Side View of Operational Attachment

Appendices

[pic]

Cross Sectional View of Robot with Balloons and Operational Attachment

[pic]

Cross Sectional View of Robot without Balloons or Operational Attachement

Appendices

[pic]

Electronics Used for Controlling the Robot

[pic]

Close up of one of the Stepper Motor Controlling Boards

Appendices

[pic]

Stepper Motors and Motors mount, Part of External Assembly

[pic]

Regulator Used to Control Air Pressure, Part of External Assembly

Appendices

[pic]

Tether Picture both Coiled and Separated

[pic]

Test Tube Course

Appendices

Motion of Robot

[pic]

[pic]

Appendices Motion of Robot continued

[pic]

[pic]

Appendices

Motion of Robot continued

[pic]

[pic]

Appendices

Motion of Robot continued

[pic]

-----------------------

10/32 THD

Attach Bladders

1/16 Inch Hole

Fishing Line Runs Through

Spring Surrounds

Inflate Following Anchor Balloons

Inflate Extension Balloons

Inflate Leading Anchor Balloons

Deflate Following Anchor Balloons

Deflate Extension Balloons

Inflate Following Anchor Balloons

Deflate Leading Anchor Balloons

( Backward – Forward (

Control Leads

Exhaust

To Balloons

From Main Air Tube

Silicone Spacer

Pinched section of balloon

Knot tied in excess end of anchor balloon

................
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