Design and Testing of a Novel Adhesion and Locomotion Method for Wall Climbing Vehicles

256 Pages·2016·7.89 MB·English

DESIGN AND TESTING OF A NOVEL COMBINED ADHESION AND LOCOMOTION METHOD
FOR WALL CLIMBING VEHICLES

A Thesis
presented to
the Faculty of California Polytechnic State University,
San Luis Obispo

In Partial Fulfillment
of the Requirements for the Degree
Master of Science in Mechanical Engineering

by
James Roy Stefani
June 2016
© 2016
James Roy Stefani
ALL RIGHTS RESERVED

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COMMITTEE MEMBERSHIP

TITLE: Design and Testing of a Novel Combined Adhesion and Locomotion
Method for Wall Climbing Vehicles
AUTHOR: James Roy Stefani
DATE SUBMITTED: June 2016

Thomas Mackin, Ph.D.
COMMITTEE CHAIR:
Professor of Mechanical Engineering
John Ridgely, Ph.D.
COMMITTEE MEMBER:
Professor of Mechanical Engineering
Joseph Mello, Ph.D.
COMMITTEE MEMBER:
Professor of Mechanical Engineering

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ABSTRACT
Design and Testing of a Novel Combined Adhesion and Locomotion Method for Wall Climbing Vehicles
James Roy Stefani
The objective of this project was to design, construct and test a wall climbing vehicle which uses a novel
vacuum tread system for both adhesion and locomotion. The design and manufacturing of this proof of
concept vehicle is detailed with particular emphasis on the design decisions that proved most impactful to
the performance of both the vehicle and the tread system. Adhesion performance was characterized by a
series of tests that validate the concept, but also identify improvements and design recommendations for
future embodiments of the adhesion/locomotion system.

Keywords: Wall-Climbing, vacuum, sliding tread adhesion, robot, vehicle, timing belt.

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ACKNOWLEDGMENTS
There are numerous people who made this project possible that I would like to thank. Firstly, I would like
to thank Dr. Mackin. Without him there would have been no project, or funding, and I would have most
likely lost my mind without his support. So, thanks Dr. Mackin, it was an honor and a pleasure to work
with you and without your help I doubt this project would have gotten off the ground.
I would like to thank the two partner with whom I worked with on this project, Erik van Broekhoven and
Lynda Tesillo. Erik, I had a blast working with you on that proof of concept model with you and I hope you
did too. Lynda, you were with me through thick and thin, and the mutual support we provided each other
through these trying times was invaluable. I truly appreciate the friendship that we have and look forward
to continuing that friendship for years to come.
To all of the different Cal Poly shop technicians, thank you all so much for the help making this thing. In
particular I would like to thank Brett Johnson and Grant Pocklington for doing what I could not, which was
weld. I would also like to thank Larry Coolidge for helping me get my damn wheels printed and reprinted
and reprinted again.
To everyone in the grad lab, and there were far too many of you to thank individually, thank you all for
being my friends and companions through the journey that was graduate school. The support and
comradery that we shared was priceless and I will consider each of you a lifelong friend.
I would also like to thank Patrick Hutchinson for keeping me from going off the deep end during this
endeavor. You have become one of the best friends that I have ever had. I could not have finished this
project without you keeping me grounded, coherent and distracting me when it was appropriate.
Finally, I would like to thank my parents, Dave and Danielle Stefani, because without them I would truly
not have been here or gotten this far. You guys have only ever shown me love, support and respect and for
that I will forever love you. Oh, and my sister Katie too, I guess.

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TABLE OF CONTENTS
Page
LIST OF TABLES ....................................................................................................................................... xvi
LIST OF FIGURES ...................................................................................................................................... xxi
Chapter 1: Introductory Material ..................................................................................................................... 1
1.1 Problem Statement ................................................................................................................................ 1
1.2 Project Overview ................................................................................................................................... 1
1.3 Background and Survey of Existing Systems ........................................................................................ 2
1.3.1 Common Applications for Climbing Robots .................................................................................. 2
1.3.2 Major Design Principles of Climbing Robots in Non-Research Applications ............................... 3
1.3.2.1 Velocity .................................................................................................................................. 3
1.3.2.2 Mobility .................................................................................................................................. 4
1.3.2.3 Payload ................................................................................................................................... 4
1.3.2.4 Safety and Reliability ............................................................................................................. 4
1.3.2.5 Usability ................................................................................................................................. 4
1.3.3 Existing Methods for Locomotion and Adhesion ........................................................................... 5
1.3.3.1 Locomotion methods .............................................................................................................. 5
1.3.3.1.1 Arms and Legs ................................................................................................................ 5
1.3.3.1.2 Wheels and Tread ........................................................................................................... 6
1.3.3.1.3 Sliding Frame .................................................................................................................. 7
1.3.3.1.4 Rails and Wires ............................................................................................................... 8
1.3.3.2 Adhesion Methods .................................................................................................................. 9
1.3.3.2.1 Magnetic ......................................................................................................................... 9
1.3.3.2.2 Pneumatic ...................................................................................................................... 10
1.3.3.2.3 Mechanical .................................................................................................................... 12
1.3.3.2.4 Electrostatic .................................................................................................................. 12
1.3.3.2.5 Chemical ....................................................................................................................... 13
1.3.4 Designs Similar to the Proposed System ...................................................................................... 13
1.3.4.1 Treaded Robot with Passive Vacuum Suction Cups ............................................................ 14
1.3.4.2 The Tripillar ......................................................................................................................... 15
1.3.4.3 Treaded Robot with Active Vacuum Suction Cups .............................................................. 16
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1.4 Proof of Concept Model ...................................................................................................................... 17
1.4.1 Design........................................................................................................................................... 17
1.4.2 Manufacturing .............................................................................................................................. 18
1.4.3 Testing and Observations ............................................................................................................. 19
1.4.4 Results and Conclusions ............................................................................................................... 20
Chapter 2: Design .......................................................................................................................................... 22
2.1 Design Criteria .................................................................................................................................... 22
2.2 Component Selection .......................................................................................................................... 22
2.2.1 Motor Selection ............................................................................................................................ 22
2.2.1.1 Selection Criteria .................................................................................................................. 23
2.2.1.2 Selected Motors .................................................................................................................... 24
2.2.2 Power Supply Selection ................................................................................................................ 26
2.2.2.1 Selection Criterion ................................................................................................................ 26
2.2.2.2 Selected Power Supply ......................................................................................................... 27
2.2.3 Venturi Selection .......................................................................................................................... 28
2.2.3.1 Selection Criterion ................................................................................................................ 28
2.2.3.2 Selected Venturi ................................................................................................................... 29
2.2.4 Tread Selection and Design .......................................................................................................... 31
2.2.4.1 Selection and Design Criterion ............................................................................................. 31
2.2.4.2 Selected Belt Design ............................................................................................................ 34
2.3 Subassembly Design ............................................................................................................................ 39
2.3.1 Frame Subsystem ......................................................................................................................... 39
2.3.1.1 Frame.................................................................................................................................... 39
2.3.1.2 Base Plate ............................................................................................................................. 42
2.3.2 Motor Subsystem .......................................................................................................................... 43
2.3.2.1 Motor Mounting Bracket ...................................................................................................... 43
2.3.2.2 Motor Base Plate .................................................................................................................. 44
2.3.2.3 Shaft Coupler Selection ........................................................................................................ 46
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2.3.3 Vacuum Subsystem ...................................................................................................................... 46
2.3.3.1 Vehicle Inlet Manifold ......................................................................................................... 47
2.3.3.2 Venturi Mounting Brackets .................................................................................................. 48
2.3.4 Vacuum Manifold Subsystem ...................................................................................................... 49
2.3.4.1 Lower Manifold.................................................................................................................... 50
2.3.4.2 Upper Manifold Section ....................................................................................................... 52
2.3.4.3 Manifold Gasket ................................................................................................................... 54
2.3.4.4 Mounting Structure .............................................................................................................. 54
2.3.4.4.1 Adjustable Struts ........................................................................................................... 55
2.3.4.4.2 Threaded Uprights ........................................................................................................ 56
2.3.4.4.3 Spring ............................................................................................................................ 56
2.3.4.5 Fittings.................................................................................................................................. 56
2.3.5 Wheel Subsystem ......................................................................................................................... 57
2.3.5.1 Bearing Selection ................................................................................................................. 57
2.3.5.1.1 Flanged Bearing ............................................................................................................ 57
2.3.5.1.2 Thrust Washer ............................................................................................................... 59
2.3.5.2 Drive and Idler Shafts........................................................................................................... 59
2.3.5.2.1 Common Shaft End ....................................................................................................... 60
2.3.5.2.2 Drive Shaft .................................................................................................................... 61
2.3.5.2.3 Idler Shaft ..................................................................................................................... 62
2.3.5.3 Drive and Idler Wheel Design .............................................................................................. 63
2.3.5.3.1 Common Drive and Idler Wheel Design Elements ....................................................... 63
2.3.5.3.2 Drive Wheel Design ...................................................................................................... 64
2.3.5.3.3 Idler Wheel Design ....................................................................................................... 65
2.3.5.4 Brace Deign .......................................................................................................................... 66
2.3.6 Tensioner Subsystem .................................................................................................................... 68
2.3.6.1 Tensioner Clamp .................................................................................................................. 68
2.3.6.1.1 Tensioner Clamp – Interior ........................................................................................... 69
2.3.6.1.1 Tensioner Clamp – Exterior .......................................................................................... 70
2.3.6.2 Tensioner Wheel Assembly .................................................................................................. 71
2.3.6.3 Tensioner Shaft .................................................................................................................... 73
2.3.6.4 Tensioner Screw Assembly .................................................................................................. 74
2.4 Final Design Assembly........................................................................................................................ 75
Chapter 3: Manufacturing and Assembly ...................................................................................................... 76
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3.1 Bill of Materials................................................................................................................................... 76
3.2 Component Manufacturing .................................................................................................................. 76
3.2.1 Frame Subsystem ......................................................................................................................... 77
3.2.1.1 Frame.................................................................................................................................... 77
3.2.1.2 Plate ...................................................................................................................................... 79
3.2.2 Motor Subsystem .......................................................................................................................... 80
3.2.2.1 Motor Mounting Brackets .................................................................................................... 80
3.2.2.2 Motor Base Plate .................................................................................................................. 81
3.2.3 Vacuum Subsystem ...................................................................................................................... 82
3.2.3.1 Venturi Mounting Brackets .................................................................................................. 83
3.2.3.2 Inlet Manifold Assembly ...................................................................................................... 84
3.2.4 Vacuum Manifold Subsystem ...................................................................................................... 85
3.2.4.1 Lower Manifold.................................................................................................................... 85
3.2.4.2 Upper Manifold .................................................................................................................... 86
3.2.4.3 Manifold Gasket ................................................................................................................... 87
3.2.4.4 Manifold Mounting Structure ............................................................................................... 87
3.2.5 Wheel Subsystem ......................................................................................................................... 88
3.2.5.1 Drive and Idler Shafts........................................................................................................... 89
3.2.5.2 Drive and Idler Wheels ......................................................................................................... 90
3.2.5.3 Brace .................................................................................................................................... 92
3.2.6 Tensioner Subsystem .................................................................................................................... 92
3.2.6.1 Tensioner Clamp Exterior Half ............................................................................................ 93
3.2.6.2 Tensioner Clamp Interior Half ............................................................................................. 94
3.2.6.3 Tensioner Wheel Assembly .................................................................................................. 95
3.2.6.4 Tensioner Shaft .................................................................................................................... 95
3.2.7 Tread Manufacturing .................................................................................................................... 96
3.3 Assembly ............................................................................................................................................. 98
Chapter 4: Testing ....................................................................................................................................... 102
4.1 Pressure System Testing .................................................................................................................... 102
4.1.1 Venturi Reliability ...................................................................................................................... 103
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4.1.1.1 Procedure ............................................................................................................................ 103
4.1.1.2 Results ................................................................................................................................ 103
4.1.1.3 Discussion .......................................................................................................................... 104
4.1.2 Manifold Section Independence ................................................................................................. 104
4.1.2.1 Procedure ............................................................................................................................ 104
4.1.2.2 Results ................................................................................................................................ 104
4.1.2.3 Discussion .......................................................................................................................... 105
4.1.3 Tread Installation Effect and Fixed Manifold Testing ................................................................ 105
4.1.3.1 Procedure ............................................................................................................................ 105
4.1.3.2 Results ................................................................................................................................ 105
4.1.3.3 Discussion .......................................................................................................................... 107
4.1.4 Vertical Surface Testing ............................................................................................................. 108
4.1.4.1 Procedure ............................................................................................................................ 108
4.1.4.2 Results ................................................................................................................................ 108
4.1.4.3 Discussion .......................................................................................................................... 109
4.1.5 Clogged vs Unclogged Performance .......................................................................................... 109
4.1.5.1 Procedure ............................................................................................................................ 109
4.1.5.2 Results ................................................................................................................................ 110
4.1.5.3 Discussion .......................................................................................................................... 111
4.1.6 Split Manifold Testing ................................................................................................................ 111
4.1.6.1 Procedure ............................................................................................................................ 111
4.1.6.2 Results ................................................................................................................................ 113
4.1.6.3 Discussion .......................................................................................................................... 114
4.1.7 Vacuum Force Testing ............................................................................................................... 115
4.1.7.1 Procedure ............................................................................................................................ 115
4.1.7.2 Results ................................................................................................................................ 118
4.1.7.3 Discussion .......................................................................................................................... 121
4.2 Other Testing ..................................................................................................................................... 122
4.2.1 Motor Torque Testing................................................................................................................. 122
4.2.1.1 Procedure ............................................................................................................................ 123
4.2.1.2 Results ................................................................................................................................ 123
4.2.1.3 Discussion .......................................................................................................................... 125
4.2.2 Wheel Alignment ....................................................................................................................... 126
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