Path Planning for Wheeled Mobile Robots Using Core Paths Graphs

Abstract

This paper describes a novel procedure based on Core Path Graphs to generate continuously differentiable sub-optimal paths for wheeled mobile robots in the presence of obstacles. The operational scenario is first discretized with a finite dimensional grid of positions-directions pairs. A weighted and oriented graph is then defined whose nodes are the above mentioned grid points, and whose arcs correspond to minimum length trajectories compliant with obstacle avoidance constraints. Arcs are obtained via solving convex quadratic programming optimization problems. A minimum cost path search algorithm is then solved to find an optimal trajectory between two nodes of the so-called Core Paths Graph. The presence of a-priori unknown obstacles is managed by isolating on-line the non suitable arcs of the Core Paths Graph. A numerical example on a wheeled mobile robot is discussed to show the applicability of the proposed technique