Optimised Informed RRTs for Mobile Robot Path Planning

TL;DR

This paper introduces optimised informed RRT algorithms that enhance basic RRT and RRT* path planners using informed sampling and path optimisation, achieving faster convergence and better performance in mobile robot path planning.

Contribution

It applies informed sampling and path optimisation to basic RRT, creating a family of algorithms that outperform RRT* in speed and solution quality.

Findings

Optimised informed RRTs outperform RRT* in limited planning time.

Informed sampling and path optimisation improve convergence speed.

The proposed methods achieve better path quality in various scenarios.

Abstract

Path planners based on basic rapidly-exploring random trees (RRTs) are quick and efficient, and thus favourable for real-time robot path planning, but are almost-surely suboptimal. In contrast, the optimal RRT (RRT*) converges to the optimal solution, but may be expensive in practice. Recent work has focused on accelerating the RRT*'s convergence rate. The most successful strategies are informed sampling, path optimisation, and a combination thereof. However, informed sampling and its combination with path optimisation have not been applied to the basic RRT. Moreover, while a number of path optimisers can be used to accelerate the convergence rate, a comparison of their effectiveness is lacking. This paper investigates the use of informed sampling and path optimisation to accelerate planners based on both the basic RRT and the RRT*, resulting in a family of algorithms known as optimised informed RRTs. We apply different path optimisers and compare their effectiveness. The goal is to ascertain if applying informed sampling and path optimisation can help the quick, though almost-surely suboptimal, path planners based on the basic RRT attain comparable or better performance than RRT*-based planners. Analyses show that RRT-based optimised informed RRTs do attain better performance than their RRT*-based counterparts, both when planning time is limited and when there is more planning time.