Adaptive fuzzy logic compensation of actuator deadzones

A deadzone compensator is designed for nonlinear systems using a fuzzy logic (FL) controller. 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. A rigorous proof of stability and performance is given and a simulation example verifies excellent performance. It is seen that the extra signal produced by the adaptive FL deadzone compensator can be considered as an adaptive dithering term. (C) 1997 John Wiley & Sons, Inc.