Error Modeling And Compensation Of Micro Inertial Measurement Unit

Micro Inertial Measurement Unit (MIMU) has many advantages such as small volume, light weight, low cost, high reliability etc. It will be applied broadly in the field of military and civil. Inertial navigation gyroscope and accelerometer are important parts of the inertial system and its precision will directly influence the precision of inertial system. Actually, error in measurement will be caused inevitably due to many disturbing factors. On one hand, the imperfect structure of MIMU will cause error; on the other hand, error may occur due to the working environment and condition of the MIMU. The error compensation about MIMU is studied in this paper. A series of results are presented as follows:Analyses the main error factors of accelerometer and gyro according to its structural characteristics, the simple mathematic models of micro gyro and accelerometer are established based on the results of velocity and 24 position calibration.The temperature characteristics of gyroscope and accelerometer have been studied. The temperature compensation models of gyroscope and accelerometer bias have been established. Through compensation, the bias stability of the gyroscope is reduced from 126.324°/h to 9.612°/h and that of accelerometer is reduced from 0.836mg to 0.216mg.The compensation models have been further improved by pre-filtering before compensation. The bias stability is reduced to 8.964°/h and 0.176mg for gyroscope and accelerometer, respectively.Non-stationary random signal of gyro drift is studied. The AR model of the random signal is established by using stochastic signal processing methods and time series analysis theory. This method is proved by AIC rule and Kalman filter.