Dynamics and Control of Inverted Ultra-Flexible Pendulum on Cart System

Séminaire le 29 Juin 2015, 16h00 à CentraleSupelec (Gif-sur-Yvette) Amphi Blondel
Prof. Prasanna S. Gandhi

Ultra-flexible beams are useful in several flexible mechanisms having applications, for example, in high-precision positioning systems and flexible link robotic systems. They demonstrate interesting dynamics, especially when these systems are in a vertical plane. This talk focuses on a representative of such system: a vertical, large-deformation cantilever with tip mass and actuated at fixed base by a cart. The system is shown to demonstrate multiple equilibria as a function of tip mass using elastica theory. Dynamics of this system is further captured using assumed modes method and imposing length constraint to model potential energy change of tip mass (constrained Langrange formulation). Evolution of chaotic behaviour under harmonic excitation is presented in comparison with experiments. We further develop a nonlinear nested saturations based controller for stabilising the cantilever in central unstable equilibrium with cart also reaching the desired position. Multiple coordinate transformations are performed to obtain a system in feedforward chain of integrators before applying nested saturation based control. Effectiveness of control is established through simulation cases and experimental implementation.

Biography: P.S. Gandhi received the B.Eng. degree in from the University of Bombay, Mumbai in 1994 and the M.Tech degree from the Indian Institute of Technology, Bombay, Mumbai in 1996, both in mechanical engineering. He received the Ph.D. degree in mechanical engineering from the Rice University, Houston in 2001. Since 2001, he has been faculty member, currently Professor, in the Department of Mechanical Engineering at Indian Institute of Technology, Bombay, Mumbai. His research interests are in the areas of MEMS and Microsystems, Mechatronics, and Nonlinear Dynamical Systems and Control. He has been a recipient of 2006 BOYSCAST fellowship of Govt of India, 2007 Best faculty award (ME department) and Prof J.R.Issac fellowship. He has authored several patents and over 85 peer reviewed conference and journal papers. He has coordinated setup of a new laboratory Suman Mashruwala Microengineering Laboratory for research in Microdomain and has successfully developed technologies of Bulk Lithography and Microstereolithography for 3D MEMS fabrication in this laboratory. He has been a qualified teacher of stress relieving, life enhancing techniques of Art of Living foundation by Sri Sri Ravishankar.