Research On Optimization Technology Of Airborne Micro-inertial Attitude Measurement System

As a necessary airborne avionics system,MIMU(Micro Inertial Measurement Unit)provides the aircraft with the attitude information which is essential to flight safety.Due to the low cost,small size,low power consumption and other factors,the current inertial components are usually used MEMS devices to constitute attitude measurement system.MEMS IMU is gradually replacing the traditional inertial devices used in aviation aircraft.However,the accuracy of the micro-attitude measuring system can not fully meet the application requirements of some high dynamic aircrafts.Therefore,this paper studies optimization technology of the micro inertia attitude measurement system.At first,the error model of MEMS inertial device is studied in this paper.The error compensation model is used to estimate and compensate the deterministic error.The error of MEMS inertia device is calculated by FFT spectrum analysis and ALLAN variance analysis.At the same time,the main problems of MEMS gyroscope in engineering application are analyzed according to the long-term tracking of micro inertial system.Besides,the problem of poor performance of MEMS inertial sensors over time is studied in this paper.The on-line calibration of the MEMS attitude reference system using high precision master inertial navigation is studied to estimate the bias of gyroscopes.Taking the data transmission time delay into account,this paper studies the compensation of time delay to further improve the accuracy of online calibration.Finally,the effectiveness of the scheme is verified by the actual flight data.Then,due to the continuous maneuver and transonic speed,the measurement error of the micro inertia attitude measurement system increases.In this paper,the attitude-based algorithm based on atmospheric data is studied,and the motion acceleration model of atmospheric data is analyzed to compensate the motion acceleration information measured in the MEMS accelerometer and improve the measurement accuracy of the micro inertial attitude system under maneuvering conditions.At the same time,the effect of vibration noise on the MEMS accelerometer is studied,and the vibration noise is suppressed by the singular spectral decomposition method.Finally,the validity and correctness of the air-assisted attitude algorithm and the singular spectral decomposition algorithm are simulated and verified by the actual flight data.In the end,this paper focuses on the application of the MEMS attitude system as an on-board backup instrument.It needs to update the software of the navigation solution in the actual use.The remote online upgrade scheme based on the serial port is studied.The MEMS attitude measure system is installed in the narrow space.Removal of the upgrade method is more difficult.Through the process of upgrading a series of reliability measures to ensure the robustness of the system software,when the system fails to upgrade the software,the system has a certain self-healing ability.Through the above series of studies,this paper further improves the accuracy of MIMU,enhances the function of the system,and further expands its scope of use.