Micro-Machined Attitude Measurement Unit With Application in Satellite TV Antenna Stabilization

摘要

This paper introduces a micro-machined attitude measurement unit, which is composed of 3 micro-machined gyros, 3 micro-machined accelerometers, a three-axis magnetometer and an embedded computer for the signal processing. The attitude measurement unit can independently provide outputs of 3 attitude angles and 3 attitude rates. The attitude algorithm and the error model of the system are derived based on the quaternion formulation. The system errors mainly come from gyro random drift rates, which are modeled as random walks. The real-time quaternion-based Kalman filter is complemented in the embedded computer with sampling frequency of 100Hz. The testing results have shown that the system accuracy is better than 0.2° at stationary base, and reduces to 0.3° with lateral acceleration of 0.1 g/0.3Hz. The micro-machined attitude measurement unit has been successfully applied in servomechanism of satellite TV antenna stability to provide its azimuth, tilt, and their rates. These angles and rates are used for feedback signals in the servcmechanism. The accuracy of servo and stability with additive feedback of field intensity can reach +-0.5° under the condition of base swing angle +-15° and period 5s～7s, which is proved to be able to satisfy with the application on shipboard through the testing on the sea.