Batch Informed Trees (BIT*): Sampling-based Optimal Planning via the Heuristically Guided Search of Implicit Random Geometric Graphs

TL;DR

BIT* is a novel sampling-based planning algorithm that combines graph search efficiency with the scalability of sampling methods, providing faster convergence to optimal solutions in high-dimensional spaces.

Contribution

The paper introduces BIT*, a new algorithm that unifies graph- and sampling-based planning, extending incremental graph search techniques to continuous domains and demonstrating superior performance.

Findings

BIT* is probabilistically complete and asymptotically optimal.

BIT* outperforms RRT, RRT*, Informed RRT*, and FMT* in speed and solution quality.

Effective in high-dimensional robotic planning problems.

Abstract

In this paper, we present Batch Informed Trees (BIT*), a planning algorithm based on unifying graph- and sampling-based planning techniques. By recognizing that a set of samples describes an implicit random geometric graph (RGG), we are able to combine the efficient ordered nature of graph-based techniques, such as A*, with the anytime scalability of sampling-based algorithms, such as Rapidly-exploring Random Trees (RRT). BIT* uses a heuristic to efficiently search a series of increasingly dense implicit RGGs while reusing previous information. It can be viewed as an extension of incremental graph-search techniques, such as Lifelong Planning A* (LPA*), to continuous problem domains as well as a generalization of existing sampling-based optimal planners. It is shown that it is probabilistically complete and asymptotically optimal. We demonstrate the utility of BIT* on simulated random worlds in $\mathbb{R}^2$ and $\mathbb{R}^8$ and manipulation problems on CMU's HERB, a 14-DOF two-armed robot. On these problems, BIT* finds better solutions faster than RRT, RRT*, Informed RRT*, and Fast Marching Trees (FMT*) with faster anytime convergence towards the optimum, especially in high dimensions.