DEVELOPMENT AND EXPERIMENTAL TESTING OF AN AMPHIBIOUS VEHICLE by Joseph G. Marquardt A Thesis Submitted to the Faculty of The College of Engineering and Computer Science in Partial Fulfillment of the Requirements for the Degree of Master of Science Florida Atlantic University Boca Raton, Florida May 2012 i DEVELOPMENT AND EXPERIMENTAL TESTING OF AN AMPHIBIOUS VEHICLE by Joseph G. Marquardt This thesis was prepared under the direction of the candidate's thesis advisor, Dr. Karl von Ellenrieder, Department of Ocean and Mechanical Engineering, and has been approved by the members of his supervisory committee. It was submitted to the faculty of the College of Engineering and Computer Science and was accepted in partial fulfillment ofthe requirements for the degree ofMaster ofScience. arl von Ellenrieder, Ph.D. Thesis AdVisor~_ Edgar An, Ph.D. Palaniswamy Ananthakrisnan, Ph.D. ..M-<.vvJ.A..~4A)~ Manhar Dhanak, Ph.D. a d Hashemi, Ph.D. air, Department ofOcean and Mechanical En ineering hammed Ily s Ph. Interim Dean, Co lege ofEngineering and Computer Science ~rZ~~ ii ACKNOWLEDGEMENTS I am so fortunate to have the most amazing family; Mom, Dad and Kasey, without you guys in my life I would not have accomplished what I have, or be here about to turn in a Master’s Thesis. Thank you for everything you have done for me, and your support through the past few years of school. I am also extremely grateful for my girlfriend Lori who has been there for me through everything, and always knows how to put a smile on my face. Her motivation and inspiration keeps me determined and focused. Dr. von Ellenrieder, my thesis advisor, thank you for everything you have done and taught me along the way. You were always willing to help, even if I was the fourth or fifth student in line waiting to talk to you. I also want to thank my thesis committee for their help and support. I would also like to thank Ed Henderson and Luis Padilla. I have learned so much from the two of you in the past few years, and your willingness to help and teach is unbelievable. Also, Dr. Ananthakrisnan, you are an amazing professor and I am so fortunate to have taken classes with you. All my fellow graduate students, especially Tom Furfaro, Janine Mask, Jose Alvarez, Matt Young and James Lovenbury, your help was much appreciated. Lastly, I would like to thank the Office of Naval Research for funding this research. iii ABSTRACT Author: Joseph Marquardt Title: Development and Experimental Testing of an Autonomous Amphibious Vehicle Institution: Florida Atlantic University Thesis Advisor: Dr. Karl von Ellenrieder Degree: Master of Science Year: 2012 The development and experimental testing of the DUKW-Ling amphibious vehicle was performed during the first phase of an autonomous amphibious vehicle system development project. The DUKW-Ling is a 1/7th scale model of a cargo transport concept vehicle. The vehicle was tested in the three regions it is required to operate: land, sea and the surf zone region. Vehicle characteristics such as turning radii, yaw rate and velocities were found for different motor inputs on land and water. Also, because a vehicle navigating the surf zone is a new area of research that lacks experimental data the vehicle was tested in the breaking waves of the surf zone and its motion characteristics were found, as well as the drivetrain forces required to perform this transition. Maneuvering tests provided data that was used to estimate a model for future autonomous control efforts for both land and water navigation. iv DEVELOPMENT AND EXPERIMENTAL TESTING OF AN AMPHIBIOUS VEHICLE LIST OF FIGURES .......................................................................................................... vii LIST OF TABLES ............................................................................................................ xii NOMENCLATURE ........................................................................................................ xiv 1 INTRODUCTION ...................................................................................................... 1 1.1 Problem Statement ............................................................................................... 3 1.2 DUKW 21 Background........................................................................................ 6 1.3 Current Model Description and History .............................................................. 8 1.4 Related Research .................................................................................................. 9 1.4.1 DUKW Autonomy ...................................................................................... 9 1.4.2 Vehicle Behavior ...................................................................................... 11 1.5 Contribution ....................................................................................................... 14 2 APPROACH ............................................................................................................. 21 2.1 Modification, Upgrades and System Design ..................................................... 21 2.1.1 Mechanical Conversion ............................................................................ 21 2.1.2 Electrical, Sensor and Control System Design ......................................... 33 2.2 Experimental Approach ..................................................................................... 43 2.2.1 Sensor and Test Equipment Calibration ................................................... 44 2.2.2 Vehicle Tests ............................................................................................. 49 3 RESULTS ................................................................................................................. 65 3.1 Vehicle Tests ...................................................................................................... 65 3.1.1 Rolling Resistance Testing ....................................................................... 65 3.1.2 Locating Vehicle Center of Mass ............................................................. 67 3.1.3 Dynamometer Testing ............................................................................... 70 3.1.4 Maximum Incline and Approach/Departure Anngles ................................. 75 3.1.5 Land Maneuvering Characteristics ........................................................... 83 3.1.6 Sea Maneuvering Characteristics ............................................................ 107 3.2 Systems Identification ...................................................................................... 121 3.3 Transition Region Tests ................................................................................... 130 3.3.1 Land-to-Sea ............................................................................................. 134 3.3.2 Sea-to-Landn ............................................................................................. 138 3.3.3 Vehicle in the Surf-Zone ......................................................................... 142 3.4 Froude-Krylov Excitation Forces .................................................................... 149 v 4 CONCULUSIONS .................................................................................................. 152 4.1 Recommendations for Future Work ................................................................. 153 5 APPENDIX ............................................................................................................. 156 6 REFERENCES ....................................................................................................... 219 vi LIST OF FIGURES Figure 1 – DUKW 21 Concept ........................................................................................... 1 Figure 2 - DUKW SWATH Hull ........................................................................................ 7 Figure 3 – Original 1/7th Scale DUKW-ling ....................................................................... 9 Figure 4 - Original Vehicle with Wheel Drivetrain .......................................................... 22 Figure 5 – Original Five Wheel Drivetrain ....................................................................... 24 Figure 6 - New Chain vs. Original .................................................................................... 25 Figure 7 - Tracked Vehicle Separation Ratios .................................................................. 26 Figure 8 – Tracked Drivetrain ........................................................................................... 26 Figure 9 - Conveyor Belt Track ........................................................................................ 27 Figure 10 - FBD of Vehicle Rolling Resistance ............................................................... 29 Figure 11 - Gearing System Numbering Convention ....................................................... 30 Figure 12 - Gear System Torques ..................................................................................... 32 Figure 13 - Water Sensor Schematic ................................................................................ 36 Figure 14 – RoboteQ’s RoboServer Software Operation ................................................. 38 Figure 15 - Motor Controller Hexadecimal Communication ........................................... 38 Figure 16 – Container Lifting Mechanism ........................................................................ 39 Figure 17 –Control System Block