Backlash compensation of nonlinear systems using fuzzy logic

Abstract

A backlash compensator is designed for nonlinear systems using fuzzy logic. The classification property of the fuzzy logic systems makes them a natural candidate for the rejection of errors induced by the backlash, which has regions in which it behaves differently. A tuning algorithm is given for the fuzzy logic parameters, so that the backlash 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 fuzzy logic backlash compensator is simulated on a nonlinear system to show its efficacy.

Keywords:

• Backlash compensation
• Fuzzy logic
• Nonlinear system
• Actuator nonlinearity