Deadzone compensation in motion control systems using adaptive fuzzy logic control

Abstract

A deadzone compensator is designed for industrial positioning: systems using a fuzzy logic (FL) controller. The FL approach is shown to subsume other approaches that use switching or indicator functions. The classification property of FL systems makes them a natural candidate for the rejection of errors induced by the deadzone, which has regions in which it behaves differently. A tuning algorithm is given for the FL parameters, so that the deadzone compensation scheme becomes adaptive, guaranteeing small tracking errors and bounded parameter estimates. Formal nonlinear stability proofs are given to show that the tracking error is small. The adaptive FL deadzone compensator is implemented on an actual industrial CNC machine tool to show its efficacy.