A robust compliant motion control of robot with certain hard nonlinearities using time delay estimation

Abstract

A new robust compliant motion control technique is presented for robot manipulator with certain hard nonlinearities. The control technique incorporates both time-delay estimation technique and ideal velocity feedback: the former is used to cancel out soft nonlinearities and uncertainties in dynamics model; the latter is used to mask hard nonlinearities. As a result, the proposed controller has simple structure and yet possesses robustness in the presence of certain hard nonlinearities. The same control structure can be used for both free space motion and constrained motion of robot manipulator. Through experiments on a 2-DOF SCARA type robot, the proposed controller has been compared favorably to other competent controllers, thereby confirming its effectiveness