Sequence-modification based collision-free motion planning of multiple robots workcell

Abstract

This work is inspired by the problem of planning multiple robots in a shared workspace. The goal is to find out a sequence order for coordinating the paths of robots so as to avoid collisions among them and deadlocks, that is, situations where each robot is waiting for the other to proceed. We assume that the workcell is known and the paths of robots can be planned in advance and all the robots move synchronously. These assumptions are good models of many tasks. The coordination is achieved by introducing improved A* heuristic algorithm for continuous state sequence planning in high dimensional space. The proposed method consist of two steps: 1) path planning for the robots, which taking into account avoidance of collision between the robots and the environment; 2) calculating all the possible colliding state and translating the coordinating problem into scheduling the path segments. Experimental cases are shown for the proposed algorithm and for their implementations. The results of the planning method can be applied to the industrial applications.