Research On Compound Attitude Measurement Method Based On GPS And MEMS Inertial Components

The attitude information of the carrier(yaw,pitch,roll)is an important parameter in the navigation system.Most of the traditional attitude measurement adopts MEMS inertial components.The inertial navigation system has the advantages of low power consumption,good autonomy and easy integration.It has wide applications in navigation guidance,projectiles,robots,drones,etc.,but the positioning and attitude error of the inertial navigation system gradually accumulates with the extension of the working time,thereby affecting the measurement accuracy.The GPS measurement error does not accumulate over time and has long-term stability.However,the GPS data update frequency is low and the dynamic characteristics are poor.When the satellite signal is out of lock,the positioning accuracy is greatly reduced.Therefore,the research of inertial navigation system and GPS integrated navigation has become a hot topic in recent years.Firstly,this paper introduces the background and significance of the research,and introduces the methods of attitude measurement of inertial devices in detail,including accelerometer-based attitude measurement,magnetometer-based attitude measurement,gyroscope-based Euler angle attitude measurement,The attitude measurement of the direction cosine method and the quaternion method is analyzed,and their advantages and disadvantages are analyzed.The advantage of the quaternion method for attitude measurement is determined.At the same time,the GPS single-antenna attitude measurement and GPS dual-antenna attitude measurement are introduced in detail.Based on the GPS single-antenna attitude measurement,the acceleration information measured by the accelerometer is proposed to compensate the pseudo-attitude angle of the single-antenna measurement.Secondly,according to the problem of inertial navigation system and GPS data fusion method,the Extended Kalman and Unscented Kalman filter are introduced in detail.For the defects of these two kinds of filtering,an Modified Strong Tracking Unscented Kalman filter is proposed,which is effectively integrated the output data of the inertial navigation system and GPS,realizing high-precision solution of carrier attitude.Finally,a brief introduction to the inertial navigation system and GPS combination mode.the MEMS Inertial Measurement Unit with laboratory model LPMS-USBAL2 is used to verify that the inertial guided posture error accumulates with time,and the UAV flight trajectory is simulated on MATLAB platform,and the experimental results verify that The accuracy of composite posture measurement is higher than that of inertial attitude measuring system,and the measurement accuracy of tight combination mode is higher than that of loose combination.Whether in loose combination or tight combination,the attitude measurement accuracy of the improved filtering fusion algorithm is greatly improved compared with other data fusion algorithms,and the positioning accuracy is up to 0.1 °.