Discrete-Time Lqr and H_2 Damping Control of Flexible Payloads Using a Robot Manipulator With a Wrist-mounted Force/Torque Sensor

摘要

This paper presents robust and optimal control methods to suppress vibrations of flexible payloads carried by robotic systems. A new improved estimator in discrete-time H_2 optimal control design based onthe Kalman Filter predictor form is developed here. Two control design methods using state-space models. LQR and H_2 Optimal Design, in discrete-time domain are applied and compared, The manipulator joint encoders and the wrist-mounted six-degree-of-freedom force/torque sensor provide the control feedback. A complete dynamic model of the robot/payload system is taken into account to synthesize the controllers. Experimental verifications of both mthods are performed using a Misubishi five-degree-of-freedom robot manipulator that carries a flexible beam. It is shown that both methods damp out vibrations of the payload very effectively.