Research And Implementation Of High-precision Driving Technology For Silicon Micro-Gyroscope

With the development of the technology of MEMS sensor,silicon micro-gyroscopes are widely used in civil,military,aerospace and other fields.High-precision silicon micro-gyroscope is one of the main technical means to achieve accurate positioning and prediction.The high-precision drive is an essential prerequisite for ensuring the accuracy of the gyroscope.Therefore,it is a great significance to improve the precision of silicon micro-gyroscope by studying the gyro drive technology.This study mainly includes the design,simulation and hardware implementation of the digital drive control circuit of the silicon micro-gyroscope,and the main contents are as follows:First,a double closed-loop control model of digital drive system of MEMS silicon micro-gyroscope was established,in which a phase locked loop(PLL)closed-loop is designed for the drive frequency control and an automatic gain control(AGC)loop is designed for the drive amplitude control.In the closed-loop PLL,a drive frequency control method of the second-order frequency-locked-loop(FLL)assisted third-order PLL is proposed by analyzing the frequency control performance of the third-order PLL.The phase detector,the filter and the second-order FLL assisted third-order PLL included in the loop were analyzed and designed.Second,the double closed-loop drive control system be composed of the third-order PLL and the second-order FLL assisted third-order PLL respectively with AGC were simulation in Matlab/Simulink software.And the simulation results verified the drive frequency method of the second-order FLL assisted third-order PLL can track the drive frequency with a higher accuracy in a shorter time.Third,based on theoretical analysis and model simulation of the drive control system,Verilog HDL language is used for hardware programs to implement fixed-point digital algorithms of drive control.The hardware algorithms mainly include IIR low-pass filter and CORDIC algorithm.Combined with the front-end filter circuit,capacitance/voltage conversion circuit and analog/digital conversion circuit,the designed drive control system of the silicon micro-gyroscope was conducted on the temperature-controlled turntable,and the results further verified the effectiveness of the drive control method.