Motion Planning of Multiple Mobile Robots Using Virtual Impedance

This paper proposes a planning method for multiple mobile robots system. It has two characteristics as follows: (1) Each robot plans a path individually. There is no supervisor. (2) The concept of cooperative motion can be implemented. A two layered hierarchy is defined for a scheme of individualrobot path planning. The higher layer generates a trajectory from the current position to the goal. The lower layer called “Virtual Impedance Method” makes a real-time plan to follow the generated trajectory while avoiding obstacles and avoiding/cooperating other robots. This layer is composed of four modules called “watchdog”, “deadlock solver”, “blockade solver” and “pilot”. The local equilibrium is detected by the watchdog and canceled by the deadlock solver or the blockade solver. Simulation results indicate eff eciveness of the proposed method.