Dynamic analysis and collision prevention for μ-disc-type inductive micro-motor driven by solenoids

Abstract

An innovative μ-disc-type inductive micro-motor is proposed and studied in this paper. The novel 3D solenoid-type electromagnetic poles are designed and fabricated by dry isotropic etching technique so that the output torque of the inductive motor can be greatly increased even though a simpler fabrication procedure is employed. On the other hand, the order-reduced dynamic model for the proposed micro-motor is established by using the singular perturbation theory. Based on the order-reduced model, a composite controller is synthesized to prevent potential collision between the disc and the center bearing by sliding mode control strategy and successfully suppress the unfavorable periodic oscillation, due to eccentricity of the disc, by an anti-swaying policy. Eventually, a few comparisons on several typical operational conditions, such as various vacuum levels, van der waals force and periodic disturbance, are also addressed and presented. The efficacy of the composite controller and the performance of the proposed micro-motor are verified by intensive simulations undertaken via the commercial software, Matlab/Simulink, and the interface module dSpace DS 1104 Board. Finally, the superior performance for the proposed micro-motor is assured, e.g., the collision between the disc and the center bearing can be successfully prevented and a constant spinning speed can be retained even if a certain degree of disturbance and uncertainty abruptly occurs.