Constrained Finite-Time Output Regulation for Robot Manipulators With Control Input Delay

Control input delay (controller action delay), saturation, and complex disturbance can significantly degrade the control performance of robot manipulators. To improve control precision and reduce settling time, this article proposes a prescribed finite-time output regulation method for robot manipulators. A dynamic compensator is presented to overcome the design difficulties caused by input delay and saturation. Based on this compensator and prescribed finite-time performance function, the presented controller can make the position tracking errors tend to a small region around zero in a prescribed finite time. Moreover, a sliding-mode disturbance observer is proposed to attenuate the negative influence of disturbance. It can estimate nonparametric state-dependent disturbance in a prescribed finite time. We also extend our method to the distributed cooperative control of multiple robot manipulators. A prescribed finite-time distributed observer is put forward, which can observe the reference signal in prescribed finite time. Both simulations and experiments are taken to demonstrate the superiority of the presented method over existing studies.