Research Of Key Technologies In Airborne MEMS Attitude And Heading Reference System Based On Multi-information Fusion Technology

As a kind of essential avionics system for modern aircraft,Attitude and Heading Reference System(AHRS)can provide real-time attitude and navigation information for the aircraft.The MEMS-AHRS based on MEMS inertial sensors has gained great potential for development,thanks to the increasing demand of miniaturization,intelligence and high mobility for aircraft in the future.In view of continuous improvements of its flight performance and deteriorating flight environment,it is very necessary to improve the precision of MEMS-AHRS and optimize its output performance in complex airborne environments.This thesis has studied on the basis of MEMS-AHRS of a certain aircraft.According to overall design requirements of the AHRS,key technologies of implementation in hardware and software design of the airborne MEMS-AHRS has been studied.First,basing on the implementation of hardware platform and design of software algorithm for airborne MEMS-AHRS,the inertial sensors error model of the MEMS-AHRS has been analyzed,by using temperature error modeling,calibration method and ALLAN identification of variance random error to compensate sensor error,designing a kind of initial alignment algorithm which has been tested and verified effectively in MEMS-AHRS.Second,study on algorithm of accelerometer with internal damping in MEMS-AHRS when the aircraft in a low dynamic state has been launched,and a kind of inertial/satellite/ atmospheric multi-information fusion algorithm has been designed,by leading into auxiliary speed information of air data system,and the performance of airborne AHRS in maneuver state has been optimized.Then combining the available airborne information sources,the research on navigation technology of multi-source fusion based on accelerometer/atmosphere data system and satellite navigation system has been conducted.By comparing and analyzing AHRS/GNSS,AHRS/ADS and other multi-source attitude reference system models,it analyzes the priority and advantages and disadvantages between different combinations of modes in airborne aviation environment,and designs a federated filtering algorithm for multi-source information fusion,which effectively improves the reliability and accuracy of navigation fusion.Finally,for this type of MEMS attitude system,temperature error,calibration error compensation test,static and dynamic sports car test verification of the attitude system were carried out successively.The test result meets the expected requirements,which has fully verified the feasibility and effectiveness of the proposed design and algorithm.At present,the state locking of this type of attitude system has been completed,achieving from prototype stage to sample machine stage.