低空突防用数字地形的平滑处理

数字地形是自主式 GPS/ MAP地形跟随 /地形回避 (TF/ TA)低空突防系统的主要信息来源之一。考虑到飞行器机动能力的限制和飞行的安全性 ,必须对实际地形进行平滑处理。文中首先提出了一种改进型的曲率限制平滑算法。在此基础上 ,给出了一种综合的坡度曲率限制平滑算法 ,它使平滑后的地形不仅满足飞行器纵向机动能力的限制 ,而且较贴合原地形也较原地形高。从而使得在平滑后的地形上进行实时航迹优化是安全可靠的。同时 ,由于平滑后的地形有坡度的限制 ,使实时航迹优化过程中对飞行器在各个方向的离地间隙的限制转化为只要限制飞行器的纵向垂直离地间隙 ,简化了实时航迹优化算法 ,从而易于工程实现。仿真结果表明 ,该算法是有效的。

Smoothing Approach to Digital Terrain for Low Altitude Penetration

Digital terrain elevation data is one of important information for autonomic TF/TA low altitude penetration system with MAP/GPS. The original terrain must be smoothed for the maneuverability and the safeness of an aircraft. The smoothing algorithm that limits the curvatures of terrain is improved, and then an integrated smoothing algorithm that limits the slopes and curvatures of terrain is presented. By applying this algorithm, the smoothing terrain not only satisfies the vertical maneuverability of the aircraft, but also is slightly higher than original terrain and similar to original terrain in shape. Hence, it is safety that flight path is optimized with the smoothing terrain in real time. In addition, because the slopes of smoothing terrain are limited, the limit of clearances between aircraft and ground in all directions is realized only by vertical clearance limited in optimization of flight path. Thus, the optimization algorithm is simplified and easily rea lized in engineering. The simulational results indicate that this algorithm is valid.