Using a chemical metaphor to implement autonomous systems

Abstract

The aim of this paper is to outline a planning system architecture which allows robots to exhibit varying degrees of autonomous behaviour. While several systems have been developed to cope with specific classes of robot tasks, a litte effort has been made towards the autonomy itself. Looking at the behaviour of animals from the ethological point of view we can suppose that even robots need to exibit a wide variety of specific behaviours. Starting from Brooks and Rosenschein's approach we can think of an autonomous system as a vertical composition of its basic behaviours, or instincts, to produce the overall emergent activity. The key point, however, is how to really obtain it considering that robot actions require to be planned in some way to complete thenmission. In this paper we propose an analternative way to design and build an autonomous system introducing the metaphor of a chemical machine. We th ink of the whole system as a set of behaviours, each implementing a specific response to incoming environmental stimuli, equipped with appropriate receptors which can be inhibited if a behaviour is not currently requested. Such an inhibitor schema is directly driven by the system itself using sensor data and the knowledge it has about its state. The advantage of this robot design lies in its ability to make explicit the adaptive capabilities of the system during its implementation.