Boundary Control of a Rotating and Length-Varying Flexible Robotic Manipulator System
Yu Liu, Wenkang Zhan, Mali Xing, Yilin Wu, Ruifeng Xu, Xinsheng Wu
Abstract
This article copes with vibration suppression and angular position tracking problems of a robotic manipulator system comprised of a rotating hub and a length-varying manipulator. To obtain precise dynamic response, the manipulator system is modeled in infinite-dimension with partial differential equations. S-curve acceleration/deceleration (S-CA/D) scheme is employed for speed regulation of the length-varying manipulator. Two novel observers are developed to estimate both the unknown disturbances and their time-derivatives, and two auxiliary systems are put forward to tackle input constraints. With assistance of the auxiliary systems and observers, two boundary control laws are put forward to manage vibration suppression and angular position tracking of the proposed manipulator system. Through Lyapunov’s theory, the closed-loop system is proved to be bounded. Numerical simulations have displayed the effectiveness of the observers and boundary control laws.