Asymptotically Optimal Sampling-Based Path Planning Using Bidirectional Guidance Heuristic
Yi Wang, Bingxian Mu
TL;DR
BIGIT* introduces a bidirectional, asymptotically optimal sampling-based motion planner that combines a meet-in-the-middle strategy with a lazy edge-checking scheme and uniform-cost search on an implicit random geometric graph (RGG). A novel bidirectional guidance heuristic is learned from a preliminary bidirectional search, which tightly constrains the informed search region and directs a second bidirectional search to a valid path, achieving faster initial solutions and quicker convergence to optimality. The algorithm employs a MM-based variant with a new stopping condition, lazy-MM in the first batch, and sparse collision checks, along with Dijkstra-based heuristic refinement to ensure admissibility. Theoretical guarantees include admissibility, asymptotic optimality, and probabilistic completeness, while experiments on abstract $\mathbb{R}^{16}$ problems and a campus drone task demonstrate superior performance compared with EIT* and AIT*. This work advances high-dimensional, informed, sampling-based planning by integrating bidirectional guidance with lazy evaluation and batch-based refinement to accelerate optimal convergence in practical robotics scenarios.
Abstract
This paper introduces Bidirectional Guidance Informed Trees (BIGIT*),~a new asymptotically optimal sampling-based motion planning algorithm. Capitalizing on the strengths of \emph{meet-in-the-middle} property in bidirectional heuristic search with a new lazy strategy, and uniform-cost search, BIGIT* constructs an implicitly bidirectional preliminary motion tree on an implicit random geometric graph (RGG). This efficiently tightens the informed search region, serving as an admissible and accurate bidirectional guidance heuristic. This heuristic is subsequently utilized to guide a bidirectional heuristic search in finding a valid path on the given RGG. Experiments show that BIGIT* outperforms the existing informed sampling-based motion planners both in faster finding an initial solution and converging to the optimum on simulated abstract problems in $\mathbb{R}^{16}$. Practical drone flight path planning tasks across a campus also verify our results.
