Navigation system for an autonomous vehicle with hierarchical map and planner

We describe the navigation system of our experimental vehicle. In this system the path planning strategy is organized hierarchically. Each level has its own map and carries out planning based on the situation the vehicle confronted using its map and sensory data. Furthermore, to improve real time operation, various modules (path planing, position estimation, obstacle detection and avoidance, etc.) of the navigation system are executed independently. Incorporation several kinds of planning strategies and maps enables the vehicle to perform suitable planning and movement for various environments in real time.