Design Of Closed-Loop Driving System For Silicon Vibratory Micro-gyroscopes Based On Fuzzy Self-tuning PI Technology

As a new type of angular velocity sensor,silicon vibratory micro-gyroscope has the advantages of small size,low power consumption and easy integration.It has broad application prospects in the military and civilian fields.The driving system of silicon vibratory micro-gyroscope usually consists of a closed loop composed of modules such as phase-locked loop(PLL)and automatic gain control(AGC)to achieve resonance function.The PLL and AGC modules are controlled by PI parameters to achieve stable closed loop.For silicon micro-gyroscope,the improvement of the quality factor(Q value)tends to increase the difficulty of controlling the frequency and amplitude of the drive mode.In addition,temperature variation and processing error affect the gyro resonance frequency,so it often has long start-up time and poor stability.Aiming at this kind of problem,this paper proposes a self-tuning PI control technology based on PI control strategy and fuzzy control theory.Firstly,the fuzzy algorithm is combined to the input deviation and the deviation change rate in the system according to the basic domain and the quantization factors,and then a series of fuzzy control rules are used to inquire and query the fuzzy quantity,and the exact correction values corresponding to the PI parameters are calculated by combining the defuzzification link.Finally,the correction values are added to the PI parameters of the previous instant to implement online correction of the PI parameters.The simulation results show that the proposed method can shorten the locking time of the driving loop for the reference amplitude and the resonant frequency compared with the traditional PI control method.In addition,the adaptive ability of the gyro related parameters is improved.In order to verify the feasibility of the proposed method,a closed-loop driving system of the gyroscope based on fuzzy PI self-tuning technology is built by FPGA.The test results show that for a gyro with a sixteen-sided structure,a resonant frequency of 17428Hz and a Q value of 90.36k,the proposed method can shorten the closed-loop setup time of the PLL from 1.038s to 0.346s with a drop of 66.7%,and the start-up time of the gyroscope can be shortened from 2.698s to 0.451s with a drop of 83.3%.In addition,the relative stability of the phase and amplitude of the driving signal reached 5.6ppm and 74ppm respectively.This method provides an effective way to realize the engineering of high precision silicon micro-gyroscopes as soon as possible.