Adaptively Informed Trees (AIT*): Fast Asymptotically Optimal Path Planning through Adaptive Heuristics
This addresses the problem of heuristic selection in path planning for robotics and autonomous systems, offering an incremental improvement over existing methods like BIT* and RRT-Connect.
The paper tackles the challenge of selecting appropriate heuristics for informed sampling-based path planning by introducing Adaptively Informed Trees (AIT*), which adapts to each problem instance using an asymmetric bidirectional search to estimate and exploit a problem-specific heuristic, resulting in solving tested problems as fast as RRT-Connect while converging towards the optimum.
Informed sampling-based planning algorithms exploit problem knowledge for better search performance. This knowledge is often expressed as heuristic estimates of solution cost and used to order the search. The practical improvement of this informed search depends on the accuracy of the heuristic. Selecting an appropriate heuristic is difficult. Heuristics applicable to an entire problem domain are often simple to define and inexpensive to evaluate but may not be beneficial for a specific problem instance. Heuristics specific to a problem instance are often difficult to define or expensive to evaluate but can make the search itself trivial. This paper presents Adaptively Informed Trees (AIT*), an almost-surely asymptotically optimal sampling-based planner based on BIT*. AIT* adapts its search to each problem instance by using an asymmetric bidirectional search to simultaneously estimate and exploit a problem-specific heuristic. This allows it to quickly find initial solutions and converge towards the optimum. AIT* solves the tested problems as fast as RRT-Connect while also converging towards the optimum.