Tf / Ta Optimal Route Planning Algorithm

The integration of terrain following/terrain avoidance is a new technique of low altitude penetration .It makes full use of the terrain masking to improve survival ability of planes. The probability of low altitude penetration can be highly improved by the TF/TA optimal trajectory planning. Trajectory planning is a key technique in realizing low-altitude-penetration. This paper focuses on studying the algorithm of the TF/TA optimal trajectory planning.The main contributions of dissertation are summarized as follows:1. The research on preflight planning algorithm based on Digital Terrain Elevation Data. In preflight planning phase, the optimal global trajectory and its safe corridor can be found via synthesizing many kinds of information by large-scale computers on earth. The method of dynamic programming based on directional chart is adopted to plan the optimal global reference trajectory. And the width of the safe corridor is specified according to the errors during planning.2. The algorithm is improved by changing the reference line during planning and avoiding the unreasonable branch in re-planning, then the planning trajectory can accomplish the task of low altitude penetration more efficiently.3. The research on real-time trajectory planning algorithm. New information obtained while flying is used to refresh the real-time trajectory every certain time. The tree search strategy combined with dynamic programming is adopted to get more accurate real time trajectory. The method "charge" is presented in this paper to dispose any possible new threats during flying. Therefore, the algorithm gets the ability of real-time modifying to let the plane avoid pop-up threats in time.