Research Of Strapdown Attitude Measurement Systembased On MEMS Inertial Devices

Attitude measurement system is the important constituent of carrier navigationand attitude control system，Because of the ability of vector to load is limited，it’sprecision directly affects the accuracy of each vector control system. It required thatthe attitude measuring system has the small mass volume, and low powerconsumption. With the development of Micro-Electro-Mechanical Systemstechnology and computer technology， vector attitude measurement usually usestrapdown inertial measurement unit，which is consist of the low cost MEMSgyroscope, accelerometer and magnetometer. For the gyroscope exists drift, in theattitude estimation process it will occur accumulated error, accelerometers will beaffected by the vibration in the process of vehicle movement. At the same time,magnetometer is a kind of magnetic resistance sensor, vulnerable to the interferenceof external magnetic field. Therefore improving the measuring accuracy of attitudemeasurement system based on MEMS is an indispensable part of the study of vehiclenavigation control.In the requirements of carrier miniaturization and navigation precision, this paperproposes a combined pose measurement system based on the micro inertialmeasurement unit/magnetometer. It analyzes the production mechanism of inertialsensors output errors, and builds the mathematical model of error compensation.Through the experiment it achieves the calibration compensation. Then using triaxialMEMS gyroscope and accelerometer constitute micro inertial measurement unit,measuring angular velocity and acceleration of gravity respectively. Using three-axismagnetometer measures the component of the geomagnetic field, constitute acombination attitude measurement system. And by the extended kalman filtering fusethe algorithm posture information that come from three inertial devices, improves theattitude measuring accuracy. Design the system hardware design and softwarealgorithm design. Attitude measuring system of semi-physical simulation effectivelysuppresses the gyroscope random drift, meeting the design requirements.