The Research On The Structure Design And Close-Loop Driving Circuit Of Differential Micromechanical Silicon Gyroscope

After analyzing the development of the vibrating micromechanical gyroscope at homeand abroad, and considering the defects of high coupling error and low sensitivity andbandwidth of the comb vibrating micromechanical gyroscope at the same time, and so on. Thedifferential of silicon micromechanical gyroscope is designed in this paper, which adopts thedouble-proof-mass structure to weaken the coupling error. The accurate matching of thenatural frequencies in drive mode and sense mode ensures the high sensitivity of thegyroscope, and the design of differential widens the bandwidth of the gyroscope. Vacuumencapsulation improves the quality factor and sensitivity of the gyroscope. At last thedifferential micromechanical gyroscope is realized by using DC automatic gain controlmethod.The basic components of gyroscope (electric capacitor and support beam) are analyzedin detail by theoretical researching and simulating. The support beams of sensing mass anddriving mass are designed with the crab-leg beam and folded beam, and the differential siliconmicromechanical gyroscope adopted static drive and comb capacity sensing detection mode.The differential silicon micromechanical gyroscope is designed in this paper. By largemounts of simulation analysis and theoretical calculation and the nature frequencies in drivemode and sense mode of gyroscope matching, high sensitivity in gyro is obtained. At last thestructure of differential silicon micromechanical gyroscope is discussed, by compare withanother gyroscope with good sensitivity proves the predominance of the bandwidth of thedifferential micromechanical gyroscope.To improve the sensitivity of gyroscope, the high depth-to-width etching of surfacemicromachining process and vacuum encapsulation technique are adopted. At the mean timethe structure of differential micromechanical gyroscope is processed by using surfacemicromachining process.The DC automatic gain control method is established to drive differential siliconmicromechanical gyroscope, and the DC automatic gain control circuit is designed to realizethis drive.