Gridworlds as Testbeds for Planning with Incomplete Information

Abstract

Gridworlds are popular testbeds for planning with incomplete information but not much is known about their properties. We study a fundamental planning problem, localization, to investigate whether gridworlds make good testbeds for planning with incomplete information. We find empirically that greedy planning methods that interleave planning and plan execution can localize robots very quickly on random gridworlds or mazes. Thus, they may not provide adequately challenging testbeds. On the other hand, we show that finding localization plans that are within a log factor of optimal is NP-hard. Thus there are instances of gridworlds on which all greedy planning methods perform very poorly, and we show how to construct them. These theoretical results help empirical researchers to select appropriate planning methods for planning with incomplete information as well as testbeds to demonstrate them. Introduction Testbeds (prototypical test domains) are planning domains that allo...