Contingency Planning for Planetary Rovers
Richard Dearden, Nicolas Meuleau, Sailesh Ramakrishnan, David Edward Smith, Rich Washington, Daniel J. Clancy · NASA STI Repository (National Aeronautics and Space Administration) · 2002
There has been considerable work in AI on planning under uncertainty. But this work generally assumes an extremely simple model of action that does not consider continuous time and resources. These assumptions are not reasonable for a Mars rover, which must cope with uncertainty about the duration of tasks, the power required, the data storage necessary, along with its position and orientation. In this paper, we outline an approach to generating contingency plans when the sources of uncertainty involve continuous quantities such as time and resources. The approach involves first constructing a “seed” plan, and then incrementally adding contingent branches to this plan in order to improve utility. The challenge is to figure out the best places to insert contingency branches. This requires an estimate of how much utility could be gained by building a contingent branch at any given place in the seed plan. Computing this utility exactly is intractable, but weoutline an approximation method that back propagates utility distributions through a graph structure similar to that of a plan graph.