Model reference adaptive inverse control of a single link flexible robot

Abstract

A new model reference adaptive inverse control algorithm is proposed for the end point position control of flexible manipulators. This controller forms a series model reference adaptive system where an estimated system inverse is placed in the feed forward path to provide an inverse control through regulation of controller parameters. It differs from other model reference control strategies in that a signal synthesis loop is included to compensate for the estimation error of the inverse controller and the output tracking error, and to improve stability. The stability of the overall control system is shown to be guaranteed using hyperstability theory. The proposed control scheme is applied to control the tip position of a single link flexible robot. A non-dimensionalized model is developed. Its zero-order hold equivalence in discrete time domain is described by an auto-regressive and moving average form. A lattice filter is utilized as a deconvolution filter. The time-delay behavior from the driving torque to the robot tip position due to robot structural flexibility is investigated.