A fundamental concern in real-time planning is the presence of dead-ends in the state space, from which no goal is reachable. Recently, the SafeRTS algorithm was proposed for searching in such spaces. SafeRTS exploits a user-provided predicate to identify safe states, from which a goal is likely reachable, and attempts to maintain a backup plan for reaching a safe state at all times. In this paper, we study the SafeRTS approach, identify certain properties of its behavior, and design an improved framework for safe real-time search. We prove that the new approach performs at least as well as SafeRTS and present experimental results showing that its promise is fulfilled in practice.
@article{arxiv.1905.06402,
title = {Improved Safe Real-time Heuristic Search},
author = {Bence Cserna and Kevin C. Gall and Wheeler Ruml},
journal= {arXiv preprint arXiv:1905.06402},
year = {2019}
}