Behavior coordination in structured environments

Abstract

Behavior coordination is a notorious problem in mobile robotics. Behaviors are either in competition or collaborating to achieve the goals of a system, which leads to requirements for arbitration and/or fusion of control signals. In most systems the arbitration is specified in terms of 'events' that denote positions or sensory input. The detection of these events allows discrete switching between groups of behaviors. In contrast, the fusion of behaviors is often achieved using potential fields, fuzzy rules or superposition. In most cases, the underlying theoretical foundation is rather weak and the behavior switching results in discrete changes in the overall system dynamics. In this paper, we present a scheme for behavior coordination that is grounded in the dynamical systems approach. The methodology provides a solid theoretical basis for analysis and design of individual behaviors and their coordination. This coordination framework is demonstrated in the context of a domestic robot for fetch-and-carry-type tasks. It is shown here that behavior coordination can be analyzed as an integral part of the design to facilitate smooth transition and fusion between behaviors.