A mechatronics testbed for manipulator joints

Abstract

This work describes the design and development of a mechatronics testbed facility allowing high fidelity and low cost testing of a manipulator's joint-prototypes in a highly flexible environment. The testbed system consists of a set of load motors whose shafts are connected to those of the joint prototypes through some torque transducers. A controller modifies the dynamics of the load motors to match the nonlinear and coupled dynamics of a manipulator links. This is made possible by incorporating the measurement of joint angles, velocities, and joint torques as well as dynamics model of the manipulator links in a composite feedforward/feedback loop. The testbed system also permits thermal-vacuum testing in order to simulate a space-like hostile environment. This makes the facility particularly useful for development and validation of new joints for space manipulators. The system is experimentally validated by comparing trajectories of the joint angles, velocities, and torques of a set of joint prototypes obtained by installing them first on a real robot and then on the mechatronics testbed