Building Symbolic Primitives with Continuous Control Routines

This paper is about the interface between continuous and symbolic robot control. We advocate describing continuous actions and their related sensing strategies as situation speciic activities, which can be manipulated by a symbolic reactive planner. The approach addresses the issues involved in turning symbolic actions into continuous activities , and using task speciic sensing routines to support those activities. Situation spe-ciic activities help preserve the convenient ction of \primitive actions" for use in planning without requiring that they all be programmed into the control system in advance. We demonstrate the utility of this architecture with an object tracking example. A control system is presented that can be re-conngured by a the rap reactive executor to achieve diierent tasks. We show how this system allows us to build interchangeable tracking activities that use diierent sens-ing/action feedback loops in diierent situations .