Research On MEMS AHRS Integration Technology And Optimization Design

AS an essential airborne avionics system of aircraft, Attitude and Heading ReferenceSystem(AHRS) can provide posture and sailing information.The AHRS is required to develop towardminiaturization and low-power as a result of the development direction of miniaturization, intelligenceand high motorization of future aircraft.This dissertation studies on a MIMU(Miniature InertialMeasurement Unit) based on MEMS inertial sensors,designes and integrates the MIMU.The system’senvironmental adaptability technology and calibration method of MEMS inertial sensors areresearched.Some experiments are also brought forward to verify system performance.Firstly,the intergration scheme and attitude algorithm are designed.A prototype is producted toput forward the preliminary test.The system is able to measure the acceleration, angular velocity andmagnetic information and output attitude.The analysis of sensors’ capability shows the effectivenessof the design of system data acquisition circuit.At the same time,the system performs poor underdynamic and high-temperature environment.After the intergration of MIMU,the adapblity of the system in harsh environment isanalyzed.After the research on the heat distribution based on the finite element method,the thermaldesign is put forward,which focus on optimizing the layout of the sensors in the system.Against thevibration impact on the system,the influence of the random vibration on MEMS inertial sensors istalked and the damping scheme is designed.The correctness of the design is verified through theANSYS simulation.The dissertation also emphasizes the MEMS inertial sensor calibration method as the limitationsof traditional MEMS inertial sensor calibration method.A two-step decoupling calibration method isproposed based on the fixed installed relations between sensors and the stability of non-orthogonalerror over time and temperature.The method sepatares the temperature drift error and non-orthogonalerror successfully.Tests on sensors show that the inertial sensor accuracy is increased by an order ofmagnitude in the whole temperature range.Finally,tests are brought to verify system accuracy,including laboratory precision test,randomvibration test and actual flight test.The experimental results show that the attitude measurementaccuracy can satisfy the miniature AHRS applications.