Layered safe motion planning for autonomous vehicles

Abstract

The major problem addressed by this research is how to plan a safe motion for autonomous vehicles in a two dimensional, rectilinear world. With given start and goal configurations, the planner performs motion planning which will lead a vehicle to achieve its task safely. During the planning, in addition to the safety consideration, motion's smoothness is also taken into account. The approach taken was to divide whole motion planning task into two layers. The top layer finds a global path by decomposing the free space into convex regions, then searching for an optimal global path class. The bottom layer performs local motion planning which further subdivides the planning problem into mid-portion and end-portion motion planning. The local motion planning is carried out region by region along the global path class. As results, simple motion instructions are generated for each region. For execution of planned motion, a software system, Model-based Mobile robot Language (MML- 11), was developed. This easy- to-use robot language provides users a convenient tool to program their applications through its function library. The results of the research were implemented in MML-1l and tested on an experimental robot Yamabico-11 successfully. (AN)