An Improved Theta^* Algorithm Based on Terrain Directional Traversability

An improved any-angle path planning algorithm based on Basic Theta^* algorithm is proposed.Utilizing the difference between the pitch and roll anti-overturning stability of planetary rover,terrain traversability relevant to rover heading is analyzed to distinguish obstacles and directional obstacles.Based on the obstacle map,the visibility check in node-expanding process of Basic Theta^* is improved to a traversability check,hence paths that could traverse directional obstacles could be screened.Simulation experiments show that,the proposed algorithm overcomes the limitation of Basic Theta^* as well as it could utilize rover characteristics more thoroughly and find the shortest path on complex terrains which are not traversable in traditional methods.It extends the rovers'range and working capability,hence it is practical for rough terrain trek,exploration of the bottom of crater and such special missions on planetary surface.