Trajectory Planning for Hypersonic Vehicle Using Improved Sparse A* Algorithm

The trajectory planning of hypersonic vehicle is an important problem for its safe flight. This paper analyzes the characteristics of trajectory planning for hypersonic vehicle and deduces the models of the threat field, the geometrical constraint, the aerothermal constraint and the constraint for fuel and path, which directly influence the flight trajectory of hypersonic vehicle. Here, we divided the trajectory planning into the mission level route planning and the tactical level rout planning with the hierarchical theory. Finally, the improved Sparse A* algorithm with variable step is designed and simulated. The simulation results verify that this method has the advantages of high speed and strong stability. The planned trajectory can satisfy all the flight demands of the hypersonic vehicle and can dodge all kinds of threat.

I. Introduction

The hypersonic vehicle has an important position in the long range accurate stroke system in the future, because of its high velocity, high precision, strong penetration, powerful destroy capability, small mass and low cost. As a key technique of hypersonic vehicle, the trajectory planning must be studied. The aim of trajectory planning is to look for a trajectory from the start point to the target which satisfies some performance index under the appointed constraints. This kind of performance index should have a minimum revelation and a maximal existence. Trajectory planning is an integrated, interdisciplinary item which relates to many other domains, such as: flight dynamics, geography information, radar technology, navigation, computer, artificial intelligence and simulation etc. ^[1]