Research On Measurement Of Mortar Roll Angle Based On Accelerometer And Micro Silicon Gyroscope

The use of guided mortars can significantly improve the operational capability of mortar systems and is therefore currently undergoing intensive research and development by the world’s leading military forces.In-depth research work on guided mortar attitude measurement is necessary because only by accurately acquiring the mortar attitude can it be guided.The silicon micromechanical gyro without drive structure is a kind of gyroscope based on MEMS technology,which can achieve measurement without external drive structure,and has the advantages of low cost and high overload resistance.In the current military field,it has been widely used in the attitude measurement task of mortar shells.However,the output signal of this gyro is noisy in the case of low carrier spin speed and gentle ballistic trajectory,and it is difficult to obtain effective signal.Theory and experiments show that the accelerometer has a clear sinusoidal signal characteristic at low carrier spin speed and gentle trajectory,and it is easy to solve the rotation angle.In solving the projectile attitude,the micromechanical gyro and accelerometer without drive structure have the basis of information fusion.This paper addresses the shortcomings of the driverless silicon micromechanical gyro,and proposes a scheme of combined attitude measurement system with driverless structure silicon micromechanical gyro and accelerometer to realize the complementary advantages.The main research work of this paper is as follows:(1)In order to solve the problems of single undriven structure silicon micromechanical gyroscope in gentle ballistic attitude solving,a combined measurement method of accelerometer and micro silicon mechanical gyro is proposed.In this method,complementary sensor measurement technology is adopted to make full use of the advantages of the two sensors,so as to effectively improve the reliability and accuracy of the combined attitude measurement system.(2)In the attitude solution algorithm,the extended Kalman filter is used to complete the signal filtering,the Hilbert algorithm to complete the full-cycle attitude solution,and the adaptive complementary filtering algorithm to complete the solution information fusion of silicon micromechanical gyro and accelerometer without drive structure.Through simulation verification,we can see that this algorithm can improve the accuracy of the attitude solution.(3)In terms of hardware,the signal processing circuit is designed based on STM32 chip to realize voltage conversion,data acquisition,attitude algorithm solving,and data communication functions.(4)In the experiment,the combined measurement system of accelerometer and undriven silicon micromechanical gyroscope is used in the three-axis precision turntable.Through the analysis of the experimental results,the effectiveness of the system in improving the accuracy of the rolling Angle solution is further verified.The maximum error of the rolling Angle solution is about 4°,and the expected effect is achieved.