Reactivity in a Logic-Based Robot Programming Framework

A robot must often react to events in its environment and exceptional conditions by suspendingor abandoning its current plan and selecting a new plan that is an appropriate response to the event. This paper describes how high-level controllers for robots that are reactive in this sense can conveniently be implemented in ConGolog, a new logic-based robot/agent programming language. Reactivity is achieved by exploiting ConGolog's prioritized concurrent processes and interrupts facilities. The language also provides nondeterministic constructs that support a form of planning. Program execution relies on a declarative domain theory to model the state of the robot and its environment. The approach is illustrated with a mail delivery application. Introduction Reactivity is usually understood as having mainly to do with strict constraints on reaction time. As such, much work on the design of reactive agents has involved non-deliberative approaches where behavior is hardwired (Brooks 1986) o..