Research On Measurement And Control Technology Of Silicon Micro Gyroscope Based On Digital Correction And Feedback

As a kind of Micro-Electro-Mechanical-Systems(MEMS)inertial sensors used for measuring the rotational speed or rotation angle,silicon micro-gyroscopes are intensively focused in the field of military and civilian because of the advantages of small volume,light weight,low cost,and easy to realize the digital and intelligent.This dissertation studies the dual-mass line vibration silicon micromachined gyroscope independently devoloped by the research group.Based on open-loop detection,quadrature error correction and force feedback closed-loop detection technology are researched on the basis of FPGA digital platform.The main research works are as follows:(1)Silicon micro-gyroscope working principle is analyzed and the dynamic equation and the motion law are derived.The basic structure of silicon micro-mechanical gyroscop devoloped in our laboratory is expounded.And the digital control system overall scheme is designed on the basis of the structure.These works indicate the direction for the implementation of each module.(2)The causes and hazards of the quadrature error are analyzed.According to the detection force feedback comb teeth and the quadrature correction comb teeth in the gyroscope structure,the quadrature force and quadrature stiffness correction schemes are designed respectively.According to the two schemes,the quadrature error closed-loop correction model was constructed separately and simulated in Matlab/Simulink to verify the feasibility of the scheme.The experimental results of the two schemes show that compared with the open-loop detection in the uncorrected state,two quadrature correction schemes can reduce the gyro bias and improve the gyro drift.Compared with the correction effect of the two schemes,the orthogonal stiffness correction is better than the orthogonal force correction.(3)The working principle of the open-loop detection of silicon microgyroscope is studied.The open-loop detection model of silicon microgyroscope is established.The performance index of open-loop detection system is deduced and analyzed.On this basis,using the feedback force comb teeth in the gyro structure,a closed loop detection model based on force feedback is constructed,and a closed loop corrector is designed.The closed-loop detection system is simulated in Matlab/Simulink.The simulation results show that the closed-loop detection system can effectively balance the Coriolis force.At the same time,the closed-loop corrector effectively expands the system operating bandwidth.The experimental test results verify the improvement of the gyro performance based on the closed loop detection system based on force feedback.(4)According to the analysis and simulation results of each part of the silicon micro gyroscope digital measurement and control system,the key algorithm in the measurement and control system is realized on the FPGA digital platform.An experimental prototype is made,and the performance test of the silicon microgyroscope experimental prototype is performed with reference to the domestic micromachined gyroscope test specification.The test results show that compared to the open-loop detection scheme,the overall performance of the siliconmicrogyroscope is improved significantly by adopting orthogonal stiffness correction and force feedback closed-loop detection technology.