小倾角下空间后方交会算法辅助的SINS/GPS姿态位置解算

Attitude and position calculations for SINS/GPS aided by space resection of aeronautic single-image under small inclination angles

利用航拍图像匹配技术辅助导航系统参数解算,通常要求飞行器姿态角近似为零。提出借用航空单像空间后方交会算法实现小倾角下SINS/GPS组合导航系统的姿态位置估计。推导了载体与航拍镜头固连且横滚角、俯仰角不为零情况下,以SINS输出的姿态角作为参数对航拍图片进行仿射变换的公式。进一步提出用上述仿射变换后的航拍像片参与地图匹配,匹配所得的控制点经空间后方交会解算,结果用以修正组合系统姿态和位置量。仿真试验表明:在静态小倾角情形下,方法能够减小迭代次数,缩短导航解算时间;即使在倾角达到20°,仍可不失效地为载体提供位置姿态信息。模拟飞行器直线平飞动态情形,验证了所提出的辅助算法可获得较好的位置估算精度。

When it comes to the issue of parameter estimates for navigation aided by aerial images matching technology, a requirement should be satisfied that the attitudes for the aerocrafts approximately equal to zero. In this work, the space resection algorithm based on aeronautic single-image is invoked, realizing the attitude and position estimates for the SINS/GPS with small inclination angle. Suppose the aerocraft is connected with the aerial camera and the rolls and pitches are not zeros, the attitudes derived from SINS are adopted as the parameters, which are then applied to deduce the affine transformation formula of the aeronautic images. In sequence, it is proposed that the affine transformed aeronautic images above could be involved in the map matching, and the space resection results, which are obtained from the matched control points, could be used to correct the attitude and position of the integrated navigation systems. The simulation results show that proposed method leads to reduce the number of iterations, and shorten the estimation time for navigation with static small inclination angle as well. Even if the inclination angle summed up to 20°, the derived attitude and position are also suitable to be provided to the aerocrafts without any failure. Moreover, the dynamic simulation related to the flat flying is carried out, testifying the aided solution has contributed to the better estimation precision of the navigation parameters.