Magnetic actuator design for single-axis micro-gyroscopes

Abstract

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.

Optimization and analysis of novel piezoelectric solid micro-gyroscope with high resistance to shock

“…(Chen et al 2005;Duan et al 2008;Tsai et al 2009;Zhang 2006;Xu et al 2009;Kagawa et al 2006;Xie and Fedder 2003). Adoption of micro electro mechanical systems (MEMS) technology for fabricating gyroscopes has allowed the fabrication of smaller, cheaper and much more energy efficient devices than conventional macro-sized devices (Kulygin et al 2008).…”

Levitating Micro-Actuators: A Review

“…Thus, Tsai et al inductively levitated a conducting cap-shaped rotor, and electrostatically revolved it with a speed of 2000 r.p.m. [52]. Subsequently, Kraft's group proposed a design of the accelerator and experimentally demonstrated that a 1×1 mm 2 sized and 7 µm thick micro object could be levitated to a maximum height of 82 µm and propelled forward continuously at a maximum average forward velocity of 3.6 mm s −1 [126].…”

“…The main disadvantage of the above ILMA prototypes was a very high operating temperature, rising up to 600 • C [50] due to the planar design of the micro-coils. Proposing a spiral coil design as shown in Figure 4b, Tsai et al fabricated a prototype that was able to stably levitate a conducting cap-shaped proof mass with an operating temperature of 100 • C [52].…”

“…Inductive levitation micro-actuators: (a) two coils design, I is the electric alternate current (AC) [47]; (b) spiral coil design [52]; (c) two racetrack-shaped solenoidal 3D wire-bonded micro-coils [17].…”

MEMS Gyroscopes for Consumers and Industrial Applications

“…Except for electrostatic and piezoelectric methods, rather few alternatives have been investigated and tested; examples of typical solutions presented in literature include designs based on thermal (Shakoor et al, 2009) and magnetic (Paoletti et al, 1996;Tsai et al, 2009) actuation, or optical sensing (Bochobza-Degani et al, 2000;Norgia & Donati, 2001). …”