The Research On Micro-machined Gyroscope Measurement And Control System

With the rapid development of MEMS technology,MEMS gyroscope is widely used in civil and military fields due to its light weight,small size,low power consumption,good durability and low cost.However,due to the limitation of the processing technology,the precision of the mcro-mechanical gyroscope is relatively low.Under the existing processing technology level,device structure optimization design,signal processing technology and control technology are usually used to improve the accuracy and stability of the gyroscope.This paper focuses on the research and control system of micro-mechanical gyroscope to improve the performance of micro-mechanical gyroscope.Mainly from digital closed-loop drive control system technology,vacuum package gyroscope test technology,closed-loop detection control technology.The thesis gives an overview of the development of micro-machined gyroscope and the current state of the research on micro-mechanical gyro-driven modal control system and sense modal control system at home and abroad.A detailed analysis of the model of the micro-mechanical gyroscope.According to the principle analysis of the established dynamic equation of micro-mechanical gyroscope,the driving principle of comb capacitance electrostatic force and the principle of comb capacitance sense are introduced.And gyroscope capacitance/voltage conversion circuit,finally,the overall framework of the micro-mechanical gyroscope measurement and control system is proposed.The frequency sweep test and vibration test technology are designed to obtain the resonant frequency and quality factor of the vacuum packaged gyro.The experimental results show that the sweep test method is more empirical than the setting of the sweep frequency parameter,and the sweep time can be as long as 20 min,and the measurement efficiency Not high,the vibration test system can effectively avoid the problems of the sweep test,the measurement time is shortened to about 2s,and does not depend on the tester’s experience.The comparative analysis of the self-excited closed loop drive and non-self excited closed-loop drive scheme is provided first.The proposes a non-self-excited drive closed-loop method base on CORDIC algorithm and LMS algorithm.After that,the CORDIC algorithm and LMS algorithm theory are derivate in detail,and the closed loop is implemented on the hardware circuit.The experimental results show that the stability of the driving response amplitude is 49ppm,which verifies the feasibility of the closed-loop control method.The narrow band force balance sense closed-loop based on modulation is introduced in detail,The control object of the system is derived from the angular velocity response and the Coriolis force frequency response respectively.The simulation of the system control object is simulated by Matlab software.Experimentally verifying the feasibility of the micro-mechanical gyro digital closed-loop drive analog closed-loop sense hybrid design system control scheme,The experimental results show that the scale factor of the gyro control system after closed-loop sense is 2.7mv/deg/s,the nonlinearity is 20ppm,the asymmetry is 40ppm,the zero-bias stability at full temperature is 100deg/h,the zero-bias stability at room temperature is 6.4deg/h,meet tactical level requirements.