Magnetic actuator design for single-axis micro-gyroscopes

An innovative magnetically levitated system design is presented in this paper. The proof mass, used as the seismic detection components for gyroscopes, is levitated by the presented micro-coil actuator so that the concerns that mechanical fatigue, asymmetry and misalignments, which are inevitably present in the traditional mechanical springs design, can be ruled out. In addition, the limited range of dual-axis motion of the proof mass is completely relaxed and therefore the resolution and sensitivity of the gyroscope can be greatly upgraded. That is, the proof mass can be much at higher frequencies and the stroke of the sense-mode motion can be more enlarged, in comparison with the conventional design (i.e., mechanical springs). In addition, self-sensing technique is employed to replace the gap sensors which provide the feedback signal for position regulation of the proof mass, for the sake of cost-down for mass production. A sliding mode control strategy is included to account for the effects of nonlinearity of the maglev system dynamics and hysteresis uncertainty of the micro-coil actuator. The proposed controller is verified by computer simulations and experiments to illustrate its superior capability to stabilize the inherently unstable maglev system and ensure fast response for the lateral position regulation of the seismic proof mass.