Research On On Low Cost And Micro Strapdown Inertial Navigation System Based On MEMS

With continuous development of strapdown inertial navigation system(SINS) in the field of military and civilian, the requirements of the low-cost micro strapdown inertial navigation system contains embedded, modular and high integration are increasing. In addition, driven by the sensor technology and semiconductor technology, the inertial sensor of the micro electro mechanical system(MEMS) also has a new breakthrough. Therefore, the research on MEMS low cost miniature strapdown inertial navigation system is inevitable. In this paper, the research is based on several key technologies of MEMS low cost miniature strapdown inertial navigation system. Finally, carries out the design schemes according to the results of the study.The main work in this paper includes:First, this part analyses the error source of MIMU and establishes the error mathematical model expression of MIMU. On the basis of the error mathematical model expression of MIMU, this article determines the MIMU deterministic error coefficient through the MIMU calibration experiments. Then, analyzes the random error sources of the MEMS inertial components and the commonly used modeling methods. In this study, five kinds of random noise of MEMS gyroscope are separated by Allan variance method, and the random noise coefficient of MIMU is calculated. Then, the paper analyzes the MEMS gyroscope random noise using time series in order to establish the ARMA model. At last, the model is filtered by Kalman filter to determine the validity and correctness of Kalman filter by analyzing the characteristics of data.Secondly, the general algorithm of SINS attitude information is studied. The advantages and disadvantages of the two algorithms are clearly defined, through the study of attitude algorithm of the quaternion method and rotation vector algorithm. In addition, on the basis of the decoding algorithm of traditional SINS speed position, we provides another method to proof sculling compensation algorithm. In this paper, by analyzing the geometrical principle of taper error sources and the traditional cone error compensation, presents a structure based on the angular rate input in order to improve the cone error compensation algorithm.The expression of the new coning compensation algorithm are deduced. Furthermore, the validity of the new algorithm is verified by theoretical analysis and mathematical simulation.Finally, according to the research of several major technology of low cost micro Strapdown inertial system based on MEMS, put forward a kind of MEMS strapdown inertial system design scheme with low cost and small size. This design scheme has the features of embedded, modular, multi-functional. The scheme uses TMS320C6678 multicore DSP as the core processing unit, with six axes inertial measurement unit MPU6050 as the main inertial sensors. In addition, the hardware structure of the strapdown inertial system is analyzed, and the selection principle of the main chip is described. In this paper, the main circuit diagram of the DSP central processing unit and the MEMS inertial measurement unit are given, and the initialization of the software system is introduced. In the end, on the completion of program design we verify the feasibility of the scheme design and the correctness of the theoretical research through the strapdown inertial system dynamic experiment.