Data based modelling and identification of nonlinear SDOF MOEMS mirror

Abstract

Accurate modeling of MOEMS mirrors is crucial for their design and fabrication, as well as for proper control within its target applications. This paper proposes a novel identification method using a generalized nonlinear SDOF model of an electrostatically actuated 1D resonant MOEMS mirror solely based on measured scanning trajectories and the current generated by the movement of the comb-drive electrodes. The nonlinear stiffness and damping are identified from a decay measurement while the comb-drive torque and the rotor inertia are derived from an actuated decay measurement, where a constant voltage is applied. The simulation with the identified parameters closely matches the measured frequency response including bifurcations and hysteresis. Furthermore a period-based modified index of agreement is proposed for nonlinear systems showing values of over 0.995 at each period along the decay.