“Time Parametrization of Articulated Mechanical Systems”
Dr. Vicente Parra Vega, Director, Robotics Laboratory,
Robotics and Advanced Manufacturing Dept.,
Modeling and control of the spatial coordinates of Euler Lagrange articulated mechanical systems, such as robotic systems, have long been studied; however that is not the case for the control its time coordinates. Controlling the time convergence allows to tackle a number of problems in robotics which such as consistency of the differential equations, switching tracking regimes and models. Unfortunately, there is a lack of framework on how to deal with desired time convergence. In this talk, a passivity based control framework is presented based on exploiting the structural properties of the mechanical system. In this way, a family of finite time attractors is introduced, including one scheme that guarantee desired convergence time. This allows switching of tracking regimes which can easily be programmed in many robotic tasks, because it is possible to determine exactly the spatial and time attributes of a given closed-loop system. Unconstrained and constrained robots are considered, including redundant ones, to illustrate the concept of time parametrization, including for path generation. Results are presented for different robotic system, such as robot arms and hands, cooperative robots, as well as application to visual servoing, haptic interfaces and teleoperation. For non-inertial robots, the scheme is presented on humanoid and biped robots, quadrotors and submarine robots. For its experimental real time validation, an integrated closed-loop mechatronics paradigm has been developed and synthesized.
Dr. Parra Vega received his doctoral degree in Mathematical Engineering and Information Physics from the University of Tokyo, in 1995, with a postdoctoral training in the Robotics and Mechatronics Department, of the German Aerospace Agency, in 2000, and a sabbatical leave at UTD in 2010. He has published over 150 conference and journal papers, as well as 5 book chapters. His research interests include modeling and control of inertial and non-inertial electromechanical Euler Lagrange systems and its interaction with human users. He is currently a Professor and Director of the Robotics Laboratory, of the Robotics and Advanced Manufacturing Department, of Cinvestav, in Mexico.