Adaptive Nonlinear Control and Input Preshaping for Flexible-Link Manipulators; Control/Robotics Research Laboratory (CRRL)

Abstract

Adaptive input precompensators in conjunction with nonlinear controllers for flexible-link manipulators are considered in this paper. The objective is to adaptively tune the parameters of the input preshaping scheme and the rigid-body based nonlinear inner-loop controller so that a vibration free output is achieved for payload variations and parameter uncertainties. Estimation of the vibrational modes and payload is done using the Empirical Transfer Function Estimate (ETFE) system identification algorithm. Experimental results on a two-link flexible manipulator with adaptive nonlinear control and preshaping are provided to show the effectiveness of the advocated controllers.