Research On Attitude Measurement Technology Based On Geomagnetic Sensor And MEMS Gyroscope

Simply guided munitions, is mainly the conventional artillery with ballistic correction part. Through the comparison between real ballistic trajectory and the predetermined trajectory, to calculate the deviation, so as to carry out a number of actual flight trajectory correction, improve the accuracy and hit rate of ammunition. The attitude measurement system, which is the core of the correction device, has great influence on the performance and accuracy of the correction ability. Therefore, the geomagnetic sensor and MEMS gyroscope combination attitude measurement techniques were studied in this paper.Methods for establishing geomagnetic models are studied, the global models of geomagnetic field are investigated. The attitude solution model based on three-dimensional geomagnetism information and single-dimensional gyroscope information was built. The geomagnetic sensor and MEMS gyroscope attitude measurement system was designed, lays a foundation for the study of the error correction and the random error filtering algorithm.The type and characteristics of geomagnetic sensor measurement errors are analyzed, the error model of geomagnetic sensor is established. Based on the model, the static calibration based on the maximum likelihood method was studied. The online calibration method based on the least square ellipsoid fitting was studied, while the compensation parameters were used as the initial value.The types and characteristics of random noise of geomagnetic measurement system were analyzed. The Kalman filter model was established by using the improved six degree of freedom ballistic equation. The extended Kalman filter, the unscented Kalman filter were studied respectively. The geomagnetic sensor is filtered by the extended Kalman filter(EKF), the unscented Kalman filter(UKF) and the adaptive unscented Kalman filter(AUKF). The results were compared with three filtering results.After debugging, the geomagnetic sensor and MEMS gyroscope attitude measurement system works properly. The two error calibration method for the geomagnetic sensor was carried out. The results show that the combination online calibration method can effectively reduce the measurement system. The experimental results of three kinds of filtering algorithms show that the adaptive unscented Kalman filter(AUKF) has a good effect on the noise of the geomagnetic measurement system.