Design, Simulation And Circuits Of A New Solid Microgyroscope With Bulk Magnetostrictive Resonator

Gyroscope has been widely used in navigation, military, aviation andother fields since its advent. Compared with traditional gyroscope usingrotor parts, MEMS gyro using vibrating components has the superiority onlight weight, low cost, good reliability, small volume, large measuring range,strong impact resistance and so on. MEMS gyroscope has become anotherimportant development direction of gyroscope. Different from thesuccessfully developed MEMS vibratory gyroscope with suspendedsupporting beams, a new kind of solid gyro without any supporting beam,using bulky giant magnetostrictive materials (GMM) as a resonator, waspresented. For this solid microgyro with GMM resonator, its structure issimple so that high anti-impact capability can be obtained, and due to largestrain properties of the giant magnetostrictive materials, high sensitivity canbe achieved.The main research work about this solid GMM microgyro areconcluded as follows.1. Design and simulation of the solid GMM microgyro. The designedstructure of microgyro consists of GMM solid vibrator, plane square coils,magnets and GMR sensors. According to the mathematical model of GMM,vibration mode analysis of GMM vibrator was carried out using weak formequation FEM method in COMSOL which has more extensibility. Thenatural frequency,193.178KHz, is close to193.722KHz obtained usingtraditional analogue method. Then we simulate the space distribution ofmagnetic field generated by magnets and square coils respectively. Thus, allwork provide guidance for the design of the micro gyroscope’s structural parameters.2. Manufacture of the solid GMM microgyro. We elaborate the MEMSprocess of plane square coils, and obtain various widths and turns of coilstators. Then we select and buy GMM solid vibrators, bias permanentmagnets and GMR sensors. The header of GMM solid micro gyroscopewhose total size of length, width and height is less than20mm is assembledsuccessfully.3. Research on driving and detecting circuits for the solid GMMmicrogyro. The work is to design, simulate and realize a driving circuit witha steady current output capacity for coils, a detecting circuit for the signalfrom GMR sensor and a signal demodulating circuit. Then printed circuitboard is designed.4. System integration test. The method for measuring the resonantfrequency of GMM vibrator is studied. The results of measurement usingstator coils and manual wound coils as excitation respectively are very close,which proves that using bilateral planar coils as excitation for our gyroscopeis feasible. At last, a systematic experiment is carried out. The result showsour micro gyroscope is sensitive to detect the change of the input angularvelocity, which proves the design presented in this paper is feasible inprinciple.