Output-Feedback Control of a Piezomicropositioning Tube Actuator with Uncertain Nonlinearities

In [1] we proposed output-feedback tracking control with an extended high-gain observer-based feedback control for a class of systems that include unknown hysteresis nonlinearities. In this paper, we proposed the control system for a piezomicropositioning tube actuator with uncertain nonlinearities. The proposed control system has a number of features; namely, (i) it can guarantee ultimate boundedness of the tracking error, where the ultimate bound can be made arbitrarily small, for any given initial conditions and for bounded unknown exogenous inputs and modeling parameters, (ii) it provides the possibility of shaping the transient response of the closed-loop system as desired, and (iii) the proposed technique is non-adaptive inversion free technique. In this study, we developed the proposed output-feedback approach for precision motion system, and we applied this approach experimentally to a piezotube micro-positioning actuator. The main contribution of this paper is to show that an extended high-gain observer-based output-feedback control system can stabilize a class of precision motion systems with unknown hysteresis nonlinearties.