Robert Gregg's UIUC Academic Homepage

Robert D. Gregg IV University of Illinois at Urbana-Champaign
Ph.D. Candidate Graduate Research Assistant Decision and Control Laboratory Coordinated Science Laboratory President, ECE Graduate Student Association Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign E-mail: rgregg AT uiuc DOT edu Adviser: Prof. Mark W. Spong Graduate Student Senator Chair, Graduate and Professional Affairs Committee Illinois Student Senate Urbana-Champaign Senate
Education History Bachelor of Science, 2006 Christie Senior Research Scholar Arthur M. Hopkin Scholar Warren Dere Design Award Department of Electrical Engineering and Computer Sciences University of California, Berkeley Master of Science, 2007 Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign Subrobots: Reduction-based Control with Application to Three-Dimensional Bipedal Walking Robots. Master's thesis, University of Illinois at Urbana-Champaign, December 2007. Graduate Coursework ECE 517: Nonlinear and Adaptive Control (Liberzon) ECE 534: Random Processes (Coleman) ECE 528: Analysis of Nonlinear Systems (Mehta) ECE 489: Robot Dynamics and Control (Spong) GE 598: Special Topics in De-centralized Control (Stipanovic) ECE 515: Control System Theory and Design (Basar) Math 423: Differential Geometry (Ekerman) Math 447: Real Variables (Loeb)
Current Work Subrobots: Reduction-based Control of Bipedal Walking Robots Bipedal walking robots have been an area of interest for the past few decades. The implications of understanding this form of locomotion are great due to its human application. The potential for improving prosthetic limbs, navigating uneven terrestrial surfaces, and creating efficient locomotive mechanisms are among the many incentives that drive research in this field. The first of these applications is of particular interest: if we can teach robots to mimic humanoid walking, then we could build intelligent robotic prosthetics for assisted human walking. Traditional control and analysis methods become impractical with complex 3-D walking robots, motivating research in reduction-based control (based on extensions from geometric mechanics, passivity-based control, and zero dynamics) to reduce dynamics into lower-dimensional control problems. We discovered a geometric property of general robots that led to the Subrobot Theorem, which shows that any robot can be reduced to an arbitrarily lower-dimensional "subrobot" (while separately controlling the reduced degrees-of-freedom). Consequently, we have designed reduction-based control laws to achieve the first theoretical results in directional 3-D dynamic bipedal walking. Simulation Movies: (Note: If you have trouble viewing these movies through your browser, try downloading and then opening them. If you still have a codec problem, download the Intel codec bundle here -- you might have to refresh a few times to get the page to load.) Reduction-Controlled 3-D Hipped Bipedal Robot (simple steps) Reduction-Controlled 3-D Hipped Bipedal Robot (simple walking) Reduction-Controlled 3-D Hipped Bipedal Robot (rendered movie) Recent Papers: Reduction-based Control with Application to Three-Dimensional Bipedal Walking Robots. (Gregg and Spong) To appear in the 2008 American Control Conference, Seattle, WA. Finalist for Best Student Paper Award! A Geometric Approach to Three-Dimensional Hipped Bipedal Robotic Walking. (Ames, Gregg, and Spong) In the 2007 Conference on Decision and Control, New Orleans, LA.
Previous Work Bipedal Robotic Walking CHESS Bipedal Walking Group Center for Hybrid and Embedded Software Systems Department of Electrical Engineering and Computer Sciences University of California, Berkeley Advisers: Dr. Aaron Ames and Prof. Shankar Sastry Stably Extending Two-Dimensional Bipedal Robotic Walking to Three Dimensions. (Ames and Gregg) In the 2007 American Control Conference, New York City, New York. Towards the Geometric Reduction of Controlled 3-D Bipedal Walking Robots. (Ames, Gregg, Wendel, Sastry) In the IFAC 3rd Workshop on Lagrangian and Hamiltonian Methods for Nonlinear Control (LHMNL'06), Nagoya, Japan. Simulation Movies: Passive 2-D Walking of a Hipless, Point-foot Bipedal Robot Flat-Ground 2-D Walking of a Hipless, Point-foot Bipedal Robot Reduced 3-D Walking of a Hipless, Point-foot Bipedal Robot Reduced 3-D Steps of a Hipless, Point-foot Bipedal Robot Is there Life after Zeno? Taking Executions past the Breaking (Zeno) Point. (Ames, Zheng, Gregg, Sastry) In the 2006 American Control Conference, Minneapolis, MN.
Autonomous Mechatronic Racing Mechatronics Design Laboratory Department of Electrical Engineering and Computer Sciences University of California, Berkeley Adviser: Prof. Ron Fearing Team 9 (Pathfinder): Rick Mann, John Breneman, Robert Gregg NATCAR 2006 1st Place Finishers
The Pathfinder: Autonomous 1/10-Scale Racecar	Berkeley Team 9
Berkeley Engineering News, November 10, 2006 Vol. 77, no. 13F. NATCAR Movies: Pathfinder First Run Pathfinder Post-Victory Lap
Hybrid Teleoperated/Autonomous Robotic Observatories Collaborative Observatories for Natural Environments: CONE 1.0 Berkeley Automation Science Laboratory Department of Electrical Engineering and Computer Sciences Department of Industrial Engineering and Operational Research University of California, Berkeley Adviser: Prof. Ken Goldberg Teaching Tutor, Self-Paced Center Department of Computer Science University of California, Berkeley Adviser: Dr. Daniel Garcia
Links These are some links to individuals and organizations that I currently work with or that have helped me get to where I am today. Illinois Homepage of Mark W. Spong UIUC Locomotion Group Decision and Control Laboratory Coordinated Science Laboratory Homepage of Tamer Basar Homepage of Peter F. Hokayem Homepage of Aneel K. Tanwani Homepage of Yoav Sharon Berkeley Homepage of Aaron Ames Jonathan Sprinkle's Homepage Shankar Sastry's Homepage C.H.E.S.S. Bipedal Walking Group Center for Hybrid and Embedded Software Systems Homepage of Ken Goldberg Homepage of Daniel Garcia Roderick Mann's CV Other ECE Graduate Student Association Grizzle, Jessy W. EECS Web page Homepage of Ambarish Goswami David Keyes Web page