Path smoothing extension for various robot path planners

Abstract

Many path planning algorithms have previously been proposed for mobile robots to navigate from a start to a goal location in a given map. These planners generate a path which keeps a safe distance from the obstacles in the map. However, most of the global path planners generate a path with sharp and angular turns which is not desired for robot motion as robots must stop at these turns. A smooth path is desired for robot motion which allows the robot to move at nearly constant velocity. We present a novel path smoothing extension which uses the geometry of hypocycloids to smooth out the sharp and angular turns of the robot's path and generates a smooth path for the robot to traverse. The proposed technique works as an `extension' and can be used in conjunction with any of the previously proposed global path planners like D*, A*, Dijkstra, or PRM (Probabilistic Roadmap) planners. The proposed extension also generates `nodes' on the robot's path which can be used as points of retreat for the robot to avoid collision with other robots. Unlike other path smoothing algorithms which generates a wavy path for the robot and brings them close to the walls, the proposed path smoothing extension keeps straight paths of the robot straight, and smooths only the turns. We discuss the results in both simulated and real environments about the smooth paths generated by the proposed extension with different global path planners along with multirobot collision avoidance.