Planning under Continuous Time and Resource Uncertainty: A Challenge for
  AI
  We outline a class of problems, typical of Mars rover operations, that are
problematic for current methods of planning under uncertainty. The existing
methods fail because they suffer from one or more of the following limitations:
1) they rely on very simple models of actions and time, 2) they assume that
uncertainty is manifested in discrete action outcomes, 3) they are only
practical for very small problems. For many real world problems, these
assumptions fail to hold. In particular, when planning the activities for a
Mars rover, none of the above assumptions is valid: 1) actions can be
concurrent and have differing durations, 2) there is uncertainty concerning
action durations and consumption of continuous resources like power, and 3)
typical daily plans involve on the order of a hundred actions. This class of
problems may be of particular interest to the UAI community because both
classical and decision-theoretic planning techniques may be useful in solving
it. We describe the rover problem, discuss previous work on planning under
uncertainty, and present a detailed, but very small, example illustrating some
of the difficulties of finding good plans.
