A hierarchical system for automated path planning and scheduling

This paper describes a hierarchical system for dynamic path planning and scheduling among a field of moving obstacles. The solution is directly applicable to many autonomous navigation scenarios, such as movement on a manufacturing floor, navigation of surface/subsurface ships or coordination of air traffic. The overall system is discussed in terms of global/local perception and generative planning/reactive control. The development and implementation of the generative planner portion of the existing system are described in detail. In terms of real-time system performance, the multi-dimensional search problem is made tractable by applying two dependent 2-D techniques in series. First, the shortest distance, obstacle-avoiding path to the goal is calculated, then for that path, the time to the goal is optimized. In this space-time representation of the domain, time requirements can be imposed upon the goal(s) and therefore scheduling can also be accomplished.