Evolving R2 to R2+: Optimal, Delayed Line-of-sight Vector-based Path Planning

TL;DR

This paper introduces R2+ as an improved vector-based path planner that enhances search efficiency and obstacle handling by delaying line-of-sight checks and employing new abstract structures, outperforming R2 especially in complex obstacle environments.

Contribution

R2+ extends R2 by adding discarding conditions, resolving chase issues, and simplifying structures, leading to faster searches in obstacle-rich maps.

Findings

R2+ maintains R2's speed in simple environments.

R2+ significantly outperforms R2 in maps with many obstacles.

Search times are largely unaffected by start-goal distance, but depend on collision complexity.

Abstract

A vector-based any-angle path planner, R2, is evolved in to R2+ in this paper. By delaying line-of-sight, R2 and R2+ search times are largely unaffected by the distance between the start and goal points, but are exponential in the worst case with respect to the number of collisions during searches. To improve search times, additional discarding conditions in the overlap rule are introduced in R2+. In addition, R2+ resolves interminable chases in R2 by replacing ad hoc points with limited occupied-sector traces from target nodes, and simplifies R2 by employing new abstract structures and ensuring target progression during a trace. R2+ preserves the speed of R2 when paths are expected to detour around few obstacles, and searches significantly faster than R2 in maps with many disjoint obstacles.