Fuzzy Observer Based Adaptive Improved Implicit Inverse Control for Discrete-Time Nonlinear Hysteretic Systems and Its Application

Aiming at solving the control problem for discrete-time nonlinear systems (DTNSs) considering unknown hysteresis nonlinearities when only the system output is available, this article presents a novel fuzzy observer-based adaptive output-feedback control (NFOAOFC) scheme with a hysteresis compensator. The main contributions are outlined as follows. 1) A discrete-time fuzzy state observer is constructed to estimate the unmeasurable states. Then, the precise tracking control performance of DTNSs with hysteresis input described by the Preisach model is realized by designing a novel discrete-time hysteresis implicit inverse algorithm. 2) The digital low-pass filters are designed to cope with the noncausal problem in the discrete-time backstepping control method. Then, the system model transformation in discrete-time backstepping control is avoided. 3) The dielectric elastomer actuator (DEA) based motion control experimental platform is constructed, where the tracking control experiments are implemented to show the effectiveness of the proposed discrete-time fuzzy state observer and the improved discrete-time hysteresis implicit inverse control algorithm.