Experimental video of a controller for flexible-joint robots

Abstract

Summary form only given. The complete presentation was not made available for publication as part of the conference proceedings. Due to the elastic nature in which some gearing mechanisms (i.e., harmonic drives, belts, long shafts, etc.) transmit torque to the robot links, it is a widely accepted fact that the inclusion of joint flexibility in the dynamics or robot manipulators yields a more accurate model. In addition, the model for a rigid-link flexible joint (RLFJ) robot includes uncertain parameters (i.e., inertia, friction, and stiffness effects); hence, controllers that can account for the parametric uncertainty seem highly desirable. Furthermore, from an implementation point of view, it is desirable that controllers be designed to require fewer measurements (i.e., due to the increased cost, complexity, and/or noise that additional sensors add to the system). In this video, we demonstrate how an experimental test bed was constructed to enhance the flexibility of the robot link/actuator joint and then was utilized to experimentally validate a global adaptive partial-state feedback tracking controller. The experimental results showcase the fact that despite considerable flexibility in the joints, link position tracking control was maintained with a relatively high degree of precision.