The Research Of Micro Inertial Attitude Heading Reference System Based On MTi

In recent years, with the development of MEMS technology, micro-inertial sensors and measurement modules become hotspot research scholars at home and abroad. The aircraft posture system, which was built by MEMS inertial sensors, it can greatly reduce its cost and volume, during aviation, aerospace, automotive, biomedical, environmental monitoring, communications, military and the all areas people can almost exposed to has a very broad application prospects. Therefore the study is necessary.The Micro Inertial Attitude Heading Reference System is composed by Micro Inertial Measurement Systems (MEMS gyroscopes\MEMS accelerometer\ three-axis magnetometer) and computer processing system. The system uses accelerometers and magnetometers of the Earth's gravity field and the magnetic field measurements to compensate for the gyro bias, using gyro to ensure the stability of the system with dynamic acceleration. The optimal posture estimates is given by the Kalman filter. That is guaranteeing the accuracy of the attitude measurement, but also maintains the inertial characteristics of the work of the independent system.In the paper, the following work have been done:1. Through the analysis and comparison to the Construction of Attitude Heading Reference System, confirmed the Attitude Heading Reference System constructed by the three micro-gyroscope, three micro-mechanical components and triaxial accelerometer magnetometer. With this method, MTi Micro Inertial Measurement Unit system has not to reference to the introduction of outside information,it can get the sensor's output of raw data only by separating MTi Micro Inertial Measurement Unit.2. Analysis of the Micro Inertial Attitude Heading Reference System Error. According to the impact of Attitude Heading Reference System precision of sensor performance, the following parameters must be calibrated, such as zero, the scale factor, installation error, zero temperature compensation of the temperature drift. Established the sensor error model, and determined the rate gyro calibration, the location of accelerometer calibration, magnetic heading error compensation and the methods of testing temperature characteristics of the experimental and data processing, compensated by software methods to achieve the purpose of improving system accuracy.3. After compensated the MTi output original data, calculated gesture according to the Czech vector algorithm. Because of MEMS Gyro is the angular velocity Gyro, the algorithm adopted quaternion gestures law, a real-time estimation and compensation was done for Gyro bias. Attitude Kalman filter observation that equation is constructed in vector coordinate system.The results show that the use of MTi micro-Inertial Measurement Unit system to construct strap-Construction of course, posture system is small in size, low cost, and any other advantages.