Research On Demodulation Technology Of Driverless MEMS Gyroscope

Guidance of shells is an inevitable trend in the development of weapons in our country,and attitude detection of guided shells is particularly important.At present,the existing attitude detection methods include geomagnetic,micro-inertial,satellite,sun-sensitive attitude detection,integrated navigation attitude detection,etc,but they all have defects such as being easily affected by external environmental factors or having complex structures.To this end,it is proposed to use a non-driven micro-mechanical(MEMS,Micro-Electro-Mechanical System)gyroscope to detect the attitude of the guided projectile.The gyroscope not only overcomes the problems of the existing attitude detection,which are easily affected by external environmental factors and has a complicated structure,but also solves the problems of the existing microinertial attitude detection,such as the accumulation of navigation errors over time and the difficulty in obtaining the initial value of the attitude calculation.This paper mainly realizes the application of undriven MEMS gyroscope in the attitude detection of guided shells.The main research contents are:1.The structure and working principle of the non-actuated MEMS gyroscope and the existing attitude detection technology of the guided projectile are studied,and the attitude detection scheme of the guided projectile based on the non-actuated MEMS gyroscope is proposed.2.In order to meet the high-precision and high-real-time requirements of attitude detection in the shell guidance process,an adaptive optimization Kalman filter algorithm is proposed to filter the output signal of the undriven MEMS gyroscope,and the real-time solution is based on the filtered signal.The feasibility of filtering and demodulation algorithm is verified by theoretical derivation and simulation analysis.The simulation results show that the maximum pitch angle error is 0.0015°,the maximum pitch angle velocity error is 0.001°/s,the maximum roll angle error is 3.6°,and the maximum roll velocity error is 0.101r/s.This demodulation algorithm can meet the practical engineering application.3.Based on the actual engineering application requirements and the characteristics of the output signal of the gyroscope,the demodulation circuit and the upper computer communication and display part are designed and completed.The demodulation circuit part uses the A/D module to perform analog-to-digital conversion on the output signal of the undriven MEMS gyroscope,and the converted digital signal is filtered and demodulated through the STM32 control circuit,Send the demodulated attitude information to the host computer through serial communication and display it in real time.4.The filtering and demodulation algorithm is verified by experiments,and the demodulation performance of the algorithm is analyzed according to the test results.The experimental results show that the filtering and demodulation algorithm can realize the attitude detection of the guided projectile,And the maximum pitch angle error is 0.3751°,the maximum pitch angle velocity error is 0.0061°/s,the maximum roll angle error is 3.9471°,and the maximum roll velocity error is 0.0635r/s,which meet the needs of practical engineering applications.Based on the above research content,the undriven MEMS gyroscope and the corresponding adaptive optimization Kalman filter algorithm and attitude demodulation algorithm meet the technical index requirements of attitude detection in practical application engineering,and have the advantages of high precision and high speed,it has high application value for guided shells.