Topic：Feedback Explicit Finite-Time Results for Spacecraft Attitude Tracking Control
Speaker: Prof. Maruthi R. Akella, The University of Texasat Austin
Time：9:30-11:30 AM, October 16
Venue: E706, New Main Building
This seminar introduces a new class of finite-time feedback controllers for rigid-body attitude dynamics subject tofull actuation. The control structure is Lyapunov-based and is designed to regulate the configuration from an arbitrary initial state to any prescribed final state within user-specified finite transfer-time. A salient feature here is that the synthesis of the control structure is explicit, i.e., given the transfer-time, the feedback-gains are explicitly stated to satisfy the convergence specifications. A major contrast between this work and others inthe literature is that instead of resorting to feedback-linearization (to get to the so-called normal form), our approach efficiently marries the process of designing time-varying feedback gains with the logarithmic Lyapunov function for attitude kinematics based on the Modified Rodrigues Parameters representation. Saliently, this new finite-time solution extends nicely for accommodating trajectory tracking objectives and possesses robustness with respect to bounded external disturbance torques. Numerical simulations are performed to test and validate the performance and robustness features of the new control designs.
Biography of the Speaker：
Maruthi R. Akella is a tenured full professor with the Department of Aerospace Engineering and Engineering Mechanics at The University of Texas at Austin (UT Austin) where he holds the E.P. Schoch Endowed Professorship inEngineering. He received his M.E. degree in Aerospace Engineering from the Indian Institute of Science (1994), and his Ph.D. in Aerospace Engineering in 1998 from Texas A&M University. Prior to joining the UT Austin faculty, he was a postdoctoral fellow with the Yale University Center for Systems Science. Dr. Akella’s research program encompasses control theoretic investigations of nonlinear and coordinated systems, vision-based sensing for state estimation, and development of integrated human and autonomous multivehicle systems. He isthe faculty lead for the Control, Autonomy, and Robotics area at UT Austin and he directs the Controls Lab for Distributed and Uncertain Systems. His research contributions have found several highly successful applications in astrodynamics, in the control of space systems, and vision-guided robotics. Hepublished more than 150 research papers in peer-reviewed archival journals and professional conferences. For his far-reaching contributions to the field of attitude estimation and control, Dr. Akella received several prestigious awards including the Mechanics and Control of Flight Award from the American Institute of Aeronautics and Astronautics (AIAA) and the Judith A. Resnik Space Award bythe IEEE Aerospace and Electronic Systems Society. He currently serves as Technical Editor for IEEE Transactions on Aerospace and Electronic Systems (TAES), and as Associate Editor for the Journal of Guidance, Control, and Dynamics (JGCD), and the Journal of the Astronautical Sciences (JAS). He is the Chairfor the Space Flight Mechanics Technical Committee of the American Astronautical Society (AAS). Dr. Akella is a Fellow of the AAS, an Associate Fellow of the AIAA, and holds the title of IEEE Distinguished Lecturer.
School of Automation Science and Electrical Engineering