Mehdi Vali - ۱Graduate Student, University of Kashan
Behrouz Ebrahimi - Assistant Professor, Aerospace Research Institute

This paper presents the development of a dynamical model of a MEMS optical switch. An inherent weakness in the use of the model for control design is the unavailability of position information at all time due to the saturated outputs characteristics. To counteract this problem, a nonlinear observer is proposed based on sliding mode theory for the saturated output system to estimate the state variables for dynamic control of theMEMS optical switch against unknown, but bounded disturbances. Robustness and stability of the proposed observer is invoked by Lyapunov second method. The proposed nonlinear observer is then applied to robust control design. The estimated state variables are utilized to design a sliding mode controller for the MEMS optical switch at presence of uncertainties. Designed sliding mode control enables compact realization of arobust controller, tolerant of device characteristics variations, nonlinearities, and types of inherent instabilities. Finally, the effectiveness of the proposed sliding observer and controller is demonstrated through simulations. Simulation results indicate that the observer states converge to the actual states very quickly at the presence of uncertainties of the system regardless of the different initial conditions.

robustness, MEMS, optical switch, slidingmode control, sliding mode observer