Model-Free Output-Feedback Sliding-Mode Control Design for Piezo-Actuated Stage

Hysteresis in a piezoelectric actuator must be compensated for, and this compensation constitutes the main challenge high-precision motion control of piezo-actuated stages. This paper presents an output-feedback sliding-mode (SMC) scheme to suppress unknown nonlinearity; scheme, hysteresis behavior is considered external disturbance, complex models are thus not required. The functions absence transfer function system state information, robust loop-transfer recovery observer employed as noise-free differentiator estimate required signal derivatives when relevant noisy environment.