Hysteresis-Estimator-Based Adaptive Fuzzy Control for Piezoelectric Micro-Positioning Stage With Time-Varying Output Constraints

This brief addresses the high-precision motion control of piezoelectric micro-positioning stages (PMPSs) subject to time-varying output constraints, input hysteresis nonlinearity, and system uncertainties. The key features of the developed hysteresis-estimator-based adaptive fuzzy control (HEAFC) method are as follows. First, an asymmetric rate-dependent hysteresis operator is used to construct an extended fuzzy input space, enabling a fuzzy dynamic hysteresis estimator (FDHE) for real-time hysteresis estimation via adaptive fuzzy logic. Second, auxiliary functions are embedded into a backstepping-like control framework to explicitly handle time-varying output constraints. Moreover, by leveraging the structural characteristics of fuzzy systems, the HEAFC scheme avoids repeated differentiation or filtering of virtual control laws. This feature can substantially simplify the control structure. The HEAFC method guarantees prespecified constraint satisfaction and high-accuracy trajectory tracking. Lyapunov-based analysis ensures closed-loop stability, and experimental results on a PMPS demonstrate the effectiveness of the HEAFC strategy.