Robust Control of Robot Manipulator under Parameter Perturbation and External Disturbance with Adaptive Gravitational Compensation

Abstract

We consider the tracking problem for robot manipulator with unknown and time-varying parameters and disturbances belong to L₂. Proposed state feedback adaptive robust controller consists of a nonlinear compensation based on nominal parameters, a linear and a nonlinear state feedback, and an adaptation algorithm for adjustment of the gravitational parameters. The effects of time-varying parameters and disturbances on the tracking performance can be attenuated within a prescribed level. And asymptotic tracking can be achieved for vanishing disturbances, constant parameters, and set point problem. By adding feedback input to penalty variable, high gain feedback can be strategy avoided.