针对在4级海况下船体大幅度晃动,甚至丢失GPS信号的复杂环境,常规算法会导致姿态测量精度急剧下降的情形,为'动中通'中的航姿系统设计了一套姿态融合算法.在GPS有效时,卡尔曼滤波的观测量引入双天线GPS输出的航向角,解决航向角观测性弱和估计不准的问题,同时引入互补滤波得到的陀螺修正量,提高了水平姿态角的可观性,融合两种算法提高了解算精度.在GPS无效时,通过互补滤波,抑制陀螺漂移,输出高精度水平姿态角,配合天线所接收信号的强度使'动中通'正常工作.为验证算法的有效性,进行了动态实验,实验结果表明:该算法在GPS有效的情况下能保证俯仰滚动角(RMSE标准)精度在0.2°以内,航向角精度在0.5°以内,在GPS无效情况下也可使俯仰和滚动角精度长时间维持在0.3°以内,具有一定的工程应用价值.%Under complex sea environments of degree-4 sea condition, the ship hulls would wobble or even lose GPS signals, thus the conventional algorithm may lead to the sharp decline of attitude measurement accuracy. To solve this problem, an attitude measurement algorithm of the attitude measurement system is designed for "Satcom on the Move". When GPS is valid, the outputs of the dual-antenna GPS observations of course are introduced to the Kalman filter, which resolves the problem of weak observability and inaccurate estimation of azimuth. Meanwhile, the amount of gyro correction is improved by introducing the complementary filtering, which improves the observability of the horizontal attitude angle and combines the two algorithms to improve the accuracy of the calculation. When the GPS is not valid, the gyro drift is suppressed by complementary filtering, and high-precision horizontal attitude angle is output. The intensity of the received signal of the antenna is used to make the "Satcom on the Move" work normally. Finally, dynamic experiments are carried out to verify the effectiveness of the proposed algorithm: in the case of visible satellite, the accuracy of the pitch rolling angle is within 0.2° and the yaw angle is less than 0.5° (RMSE); in absence of visible satellite, the pitch and roll angle accuracies can be maintained within 0.3° for a long time. These show that the algorithm has important engineering value.
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