Variable structure model following control for industrial robots

Abstract

A variable structure model following control (VSMFC) strategy for the control of most types of industrial robots (according to a classification ofCoiffet 1983) has been presented. For 99% of the robots given in the classification of Coiffet (1983), the dynamics of each link can be represented by a simple model with the nonlinearities and coupling dynamics decoupled from the linear part (Stoten 1985). This facilitates the designer to have a modified VSMFC law, which will maintain sliding mode motion of the error and its derivative, referred to as the representative point (RP), on a user chosen switching line and to drive the RP to the origin of the error plane (error is defined as the difference between the states of the reference model and those of the plant). When in sliding mode the system remains insensitive to parameter variations and disturbances