Robust adaptive control of a class of nonlinear systems with unknown backlash-like hysteresis

This paper deals with adaptive control of a class of nonlinear dynamic syst ems preceded by unknown backlash-like hysteresis nonlinearities, where the hysteresis is modeled by a differential equation. By exploiting solution pr operties of the differential equation and combining those properties with a daptive control techniques, a robust adaptive control algorithm is develope d without constructing a hysteresis inverse. The new control law ensures gl obal stability of the adaptive system and achieves both stabilization and t racking to within a desired precision. Simulations performed on a nonlinear system illustrate and clarify the approach.