Stabilization of a Parallel-Plate Microactuator via Control Lyapunov Functions

This work aims at developing a new nonlinear control scheme based on control Lyapunov functions combined with backstepping to stabilize parallel-plate electrostatic MEMS actuators. Parallel-plate electrostatic MEMS actuators are not linearly controllable at the origin due to a strong non-linearity which comes from electrostatic forces. In the present study, a robust method is used to derive a new controller to thoroughly remove the instability region, and minimize the possibility of hitting the fixed electrode by the moveable plate. A large number of numerical simulations are performed to verify the analytical model. The resulting parallel-plate microactuator system shows no region of instability using the proposed controller. A comparison shows the robustness of the method in comparison with other solutions, and demonstrates a significant improvement in performance.Copyright © 2010 by ASME