Sparsification of Motion-Planning Roadmaps by Edge Contraction

TL;DR

This paper introduces RSEC, an algorithm that significantly reduces the size of motion-planning roadmaps with minimal impact on path quality, by contracting edges to simplify the graph.

Contribution

The paper proposes a novel edge contraction-based sparsification method for motion planning roadmaps, achieving over 98% compression with minimal path degradation.

Findings

Compressed over 98% of edges and vertices

Degraded average shortest path length by at most 2%

Maintained path quality despite significant sparsification

Abstract

We present Roadmap Sparsification by Edge Contraction (RSEC), a simple and effective algorithm for reducing the size of a motion-planning roadmap. The algorithm exhibits minimal effect on the quality of paths that can be extracted from the new roadmap. The primitive operation used by RSEC is edge contraction - the contraction of a roadmap edge to a single vertex and the connection of the new vertex to the neighboring vertices of the contracted edge. For certain scenarios, we compress more than 98% of the edges and vertices at the cost of degradation of average shortest path length by at most 2%.