Robust Biped Locomotion using Nonlinear Geometric Control

Date: 2021/01/06 - 2021/01/06

Academic Seminar: Robust Biped Locomotion using Nonlinear Geometric Control

Speaker: Tan Chen, University of Notre Dame

Time: 9:00 a.m.-10:00 a.m., January 6th, 2020 (Beijing Time)

Location: via Zoom (Meeting ID: 67524947090, Password: 283605)


Underactuated mechanical systems (UMS) have been widely studied for several decades. Examples of UMS include spacecraft, snake robots, biped robots etc, among which the under-actuation may be due to a design choice or some environmental limits. One of the most important challenges for UMS is the control problem. This talk focuses on one of the UMS applications, bipedal robots. Despite their obvious utility in a human-constructed environment, biped robots are still far from ubiquitous. The obstacles to broader practical application of biped robots can be grouped into two core control issues: robustness and efficiency. Most existing bipedal robots that locomote robustly typically do so with energetically costly gaits, so they cannot operate autonomously for long periods of time. The more efficient, less robust bipeds tend to be underactuated, with control strategies often grounded in Poincare return map analysis. The underactuated bipeds, however, has limited robustness. Therefore, this talk will present a nonlinear mechanical coupling metric, which can be used to quantify the robustness for UMS, such as the underactuated biped, and thus, improve the robustness of bipedal walking. Underactuated bipeds walking on slippery ground is a very important and challenging problem, and some results on improving the robustness of bipeds walking on slippery surfaces will also be discussed. If time permits, this talk will also cover some theoretical results about the control of general UMS, specifically, serial robots. Control analysis and design methodologies will be given.


Tan Chen is a PhD student in the Department of Aerospace and Mechanical Engineering at the University of Notre Dame. He received his BS degree in Mechanical Engineering from Shanghai Jiao Tong University (SJTU), China, and a joint MS degree from SJTU and Ecole des Mines de Douai,France. He was an Eiffel Scholarship recipient in France and has been awarded outstanding graduate student teaching award at the University of Notre Dame. His research interests are in applied mechanics and nonlinear control as applied to robotic systems and human biomechanics.