Smooth path planning by using visibility graph-like method

To achieve smooth motion of car-like robots, it is necessary to generate paths that satisfy the following conditions: maximum curvature, maximum curvature derivative, and curvature continuity. Another requirement is that human operators can manipulate the robots with ease. In this paper, a path expression methodology consisting of line segments, circular arcs and clothoid arcs is presented. In addition, a method of global path generation with a visibility graph is proposed. To establish this method, the following steps are proposed: (a) the arrangement of subgoals (middle points) and (b) the construction of the graph for path generation. By using the proposed method, the paths were shortened 14% on average.

1. Introduction

Generating smooth paths is essential for mobile robot navigation. Since smooth motion may prevent skidding and improve the robot's dead reckoning ability, a robot can move for a long distance without receiving extra visual or range information. Thus, this problem is the focus in this paper. Specifically, we propose a path-generating method for a mobile robot to reach from a certain initial configuration to a target configuration as fast as possible under known environment without collision (Fig. 1).