Robot planning in the space of feasible actions: two examples

Several researchers in robotics and artijicial intelligence have found that the commonly used method ofplanning in a state (conjiguration) space is intractable in certain domains. This may be because the C-space has very high dimensionality, the “C-space obstacles” are too diflcult to compute, or; because a mapping between desired states and actions is not straightforward. Instead of using an inverse model that relates a desired state to an action to be executed by a robot, we have used a methodology that selects between the feasible actions that a robot might execute, in effect, circumventing many of the problems faced by configuration space planners. In this paper we discuss the implications of such a method and present two examples of working systems that employ this methodology. One system drives an autonomous cross-country vehicle while the other controls a robotic excavator performing a trenching operation.