Design and testing of a Stewart Platform Augmented Manipulator for space applications

An innovative nine degree-of-freedom robotic manipulator intended for neutral buoyancy space simulation research has been developed. The manipulator design specifications were driven by two primary goals; to duplicate and surpass the operational characteristics of the Shuttle Remote Manipulator System (SRMS) and to serve as a robust, neutral-buoyancy positioning system. The ability to provide fine tip positioning as well as large force production capability was realized by decoupling the system design into a three degree-of-freedom, revolute joint, manipulator arm augmented by a six degree-of-freedom, parallel-link, micromanipulator. Hybrid pneumatic/hydraulic actuators were developed to overcome neutral buoyancy constraints and to satisfy safety considerations. Finally, a variety of joint-based control schemes and Cartesian trajectory planning methods were implemented and studied. This research was funded by the NASA Office Technology (NASA Grant NAGW-21). Thesis Supervisor: of Aeronautics and Space Professor David L. Akin Rockwell Assistant Professor of Aeronautics and Astronautics Acknowledgements Two years ago as a fledgeling graduate student, I approached Dave and asked "What would be a really neat thing to build? " He replied, "Ummm, well, I've got an idea for a pneumatic positioning arm. It would be like the big arm down at Marshall [Space Flight Center] but much stronger. And I figure that we can make it strong enough to use in one-g, so we can take it to freshman open houses and tap people on the shoulder with it. " At the time I had no idea what to call the arm. A long string of attempts at naming ensued with such dubious acronyms as Big Large Arm Hopefully (BLAH) and Pneumatically Actuated Robotic Manipulator Equipped with a Synergetically Active Network (PARMESAN). After many months, and uncountable groans from everyone in SSL, I finally decided the "big arm" would be called the Stewart Platform Augmented Manipulator, and thus, SPAM was born. Where the inspiration for SPAM came from, I am uncertain. Of course there is the processed meat product of the same name to consider. But I doubt that. There is alternatively my dear friend Cindy Shen, who picked up the nickname "SPAM" when she was a freshman. But I have my doubts about this also. Lastly, there is the skit by Monty Python ("Spam, spam, spam.") involving a restaurant that only serves SPAM. This MAY be where "SPAM" originated, but then again, one can never IbC sure. There are a great number of people that I feel deserve my expressed appreciation and gratitude. First and foremost, I would like to thank Professor David Akin for his encouragement, support, and timely advice over the past few years. I am convinced that the prospect of working with Dave was the primary factor which drove me to pursue another degree at MIT. All that I have learned and gained during the past two years, I feel I owe to him. It is my sincere hope that we will be able to work together again in future days. Second, I am indebted to all the undergraduates who worked on SPAM. Paul "Jello" Duncan, deserves endless acclamations since he toiled long hours building most of the hardware and being the "SPAM Diver". I could not have asked for a more capable "right-hand man". Cecelia "Too Tall" Park should be given an award for the amazing amount of foam and fiberglassing she had to endure under my dubious guidance. I cannot thank her enough for her unwavering commitment and dedication. Paul "Moonbeam" Stach will hopefully realize his ambition of"going to the moon on a craft of his own design", but until then, I hope he will take pride in the most excellent parts of SPAM (especially the "Stach Wrench") that he built. It was great fun and a tremendous pleasure to have worked with a fellow Illini! Additionally, I owe thanks (and probably several apologies for waking 3 her) to Beth "Starlight" Kader, the "Bonus UROPer". I had no idea that hiring "Moonbeam" was a package deal, but I appreciate all of Beth's help at Pool Tests. Finally, gratitude is also due to Wisdom Franchot Coleman, Ronke Olabisi and Jen Tran. To Professor Harold "Sandy" Alexander, I extend my heartfelt appreciation for his constructive suggestions, weekend shop supervision, and for introducing me to the Advanced Missions Group at NASA-Ames. To Ping Lee, I apologize profusely for the stream of inundating purchase orders and receipts that I constantly poured on her desk. Acknowledgement must additionally be given to Al Shaw, Earle Wassmouth, and Don Weiner for having the courtesy to deal with myself and everyone associated with SPAM. To the community that is the "SSL family", my thanks go: to Rich Patten for teaching me everything about pneumatics; to Karl "Killer" Kowalski for always being amusing and wanting a good argument; to Jud "Cowardly Lion" Hedgecock for his friendship since Unified; to Ender St. John-Olcayto "Smythe" for being a great roommate, friend and confidant; to Ella "Mrs. Smith" Atkins for just being Ella (even though she decided my name should be "Fong Unit") and for always telling me "that's nice, dear"; to Rob Sanner-Blah for his invaluable advice in computer science and fabulous cookies; to Sayan "Interview-Man" Chakraborty for being an active member in the "Sleep 'Til Noon or Preferably Later Club" (may he always have a "birdhouse in his soul"); to Sam "Zonmmnrrrtech" Druker for lending me Young M.C. 's Stone Cold Rhvmin' and for sharing my disgust of Microsoft products; to Kurt "Smut-Man" Eberly for always amusing me with his "Hans and Franz" imitation; to Matt "Mattress" Machlis for throwing a frisbee (and for splattering me all over the slopes at Cannon Mt.); and to Russ "Fluffy" Howard for having the reference books on anything and everything I needed. Finally, my thanks to my family and friends who have made the past two years the best years of my life. To my parents for always giving me the encouragement and support to do whatever I wanted to do my entire life, I will always be deeply ndebted. I only hope that they know how much their love has meant to me. To my brother Tim, and sister Tammy, thanks for being silly and asking amusing questions. To Brian, Cindy, Ellen, Eric, Mini, Ryo, and Tex, thanks for everything. To Eriko, for being my friend, fellow "strobophobe" and for always amusing me. Most of all, thanks to Jessica for being the most wonderfully caring person in the world, for talking with me about anything and everything, and for giving me companionship and love. This thesis is dedicated to my parents and Jessica.