Planning with Real-Time Collision Avoidance for Cooperating Agents under Rigid Body Constraints

In automated warehouses, path planning is a crucial topic to improve automation and efficiency. This kind of planning is usually computed off-line knowing the planimetry of the warehouse and the starting and target points of each agent. However, this global approach is not able to manage unexpected static/dynamic obstacles and other agents moving in the same area. For this reason in multi-robot systems global planners are usually integrated with local collision avoidance algorithms. In this paper we use the Voronoi diagram as global planner and the Velocity Obstacle (VO) method as collision avoidance algorithm. The goal of this paper is to extend such hybrid motion planner by enforcing mechanical constraints between agents in order to execute a task that cannot be performed by a single agent. We will focus on the cooperative task of carrying a payload, such as a bar. Two agents are constrained to move at the end points of the bar. We will improve the original algorithms by taking into account dynamically the constrained motion both at the global and at the collision avoidance level.