Design And Implementation Of High Precision MEMS Micro Inertialattitude System

With the development of micro-electro-mechanical system technology,MEMS micro-inertial attitude system is widely used in production and life because of its low cost,small size,light weight,low power consumption and good portability.However,due to the low measurement accuracy of MEMS inertial sensors and the poor adaptability of the system environment,the application of MEMS micro-inertial attitude is limited in the fields of aircraft,rockets and ships.Therefore,research on high-precision MEMS micro-inertial attitude systems is of great value for the development of navigation,aerospace and aviation technologies.This paper mainly focuses on the problem that the MEMS micro-inertial attitude system is susceptible to carrier vibration signal interference and low output attitude accuracy,and carries out related design and test experiments.The main contents are as follows:(1)MEMS micro inertial attitude system design.First select the main components of the system according to the system performance requirements,and then design the system hardware,software andstructure.The system hardware circuit is divided into three parts: core system board,inertial measurement board and external communication board.The main function of the core system board is to collect MEMS inertial sensor data and obtain the carrier attitude angle through data fusion and attitude calculation;the inertial measurement board is to measure the inertial motion of the carrier;the external communication board exchanges data with the outside world.The system software includes system initialization,MEMS inertial sensor data acquisition and filtering,data calibration,attitude calculation and PC data display.In order to prevent the natural frequency of the system structure from intersecting with the carrier vibration frequency band and the natural frequency of the MEMS inertial sensor,the vibration characteristics analysis and simulation of the MEMS inertial sensor are carried out to determine the fixed frequency setting range of the system structure and optimize the system structure design.(2)Design and simulation analysis of attitude calculation algorithm.Aiming at the problem of increasing range and increasing noise of MEMS inertial sensor output signal in vibration environment,based on traditional Mahony complementary filtering,Madgwick gradient descent and extended Kalman filter,designed the improved adaptive Mahony complementary filtering,the improved Madgwick gradient descent and the improved adaptive extended Kalman filtering algorithm.Through theUAV flight simulation experiment,the attitude error of three improved algorithms is obtained from large to small: improved adaptive Madgwick gradient descent method,improved adaptive extended Kalman filter algorithm,and improved adaptive Mahony complementary filtering algorithm.Therefore,the improved adaptive Mahony complementary filtering algorithm is more suitable for the vibration environment attitude solution,which is selected as the system attitude calculation algorithm.(3)MEMS micro inertial attitude system performance test experiment.The performance test of MEMS micro-inertial attitude system includes random vibration and attitude output accuracy test.The system random vibration test shows that the system structure has isolation effect on the carrier vibration signal,and the carrier vibration signal is not amplified,which improves the system performance.The system attitude accuracy test shows that the system static maximum error value is within0.2deg and the dynamic attitude accuracy is less than 1 deg(Using high-precision micro inertial attitude system IMU520 as a reference device).Random vibration and attitude output accuracy test data show that the system has strong environmental adaptability and high attitude output accuracy.