Research On MEMS AHRS Optimization Design In Harsh Airborne Environment

As an essential airborne avionics system of aircraft, Attitude and Heading Reference System(AHRS) can provide posture and sailing information. The MEMS AHRS has huge potential due to the development of miniaturization, intelligence and high mobility of the future aircraft. Because of the requirements of special environment and high-performance, it’s very necessary to improve and optimizing the output performance of MEMS AHRS in harsh airborne environment.In view of the lower precision of MEMS gyroscope, an error model of MEMS gyroscope is established in this thesis. Based on this, a calibration and compensation algorithm is analyzed to compensate the definite error, and the method of ALLAN variance is proposed to identify the random error of MEMS gyroscope. At the time, the array of MEMS gyroscopes is designed based on the information fusion theory. Then, the performance of the array is analyzed. The above work laid the foundation for improving the accuracy of MEMS gyroscope.Considering the influence of vibration on the MEMS AHRS, the response characteristics of MEMS AHRS is analyzed in different types of vibration source excitation. Based on this, damping program is designed. Then, this damping program is verified by vibration environment test.Given that MEMS accelerometer can not accurately estimate the acceleration of gravity in high dynamic environment, a maneuver detector is designed based on the performance of MEMS AHRS in high dynamic environment. And the extend kalman filter based on Gauss-Newton method is proposed to reduce the attitude error in switching condition. Then, the maneuvering acceleration compensation algorithm in hovering condition is analyzed. Finally, the optimization plans above are verified by the simulation based on the original data of flight test.Finally, tests are brought to verify actual system accuracy, including turntable precision test, random vibration precision test and actual flight precision test. The precision test results show that the MEMS AHRS can accurately and reliably estimate attitude in harsh airborne environment.