Applying Coordination Mechanisms for Dependency Relationships Under Various Environments

Abstract

Coordination is a key functionality in multi-agent systems, and mechanisms for achieving coordinated behaviors have been well-studied. One important observation has been that different mechanisms have correspondingly different performance characteristics, and that these can change dramatically in different environments (i.e., no one mechanism is best for all domains). A more recent observation is that one can describe possible mechanisms in a domain-independent way, as simple or complex responses to certain dependency relationships between the activities of different agents. Thus agent programmers can separate encoding agent domain actions from the solution to particular coordination problems that may arise. This paper explores the specification of a large range of coordination mechanisms, for the common hard “enablement” (or “happens-before”) relationship between tasks at different agents. It also explores the impact of task environment characteristics on the choice/performance of these mechanisms. Essentially, a coordination mechanism can be described as a set of protocols (possibly unique to the mechanism), and as an associated automatic re-writing of the specification of the domain-dependent task (expressed as an augmented HTN). The idea about the separation of general knowledge and domain-dependent knowledge is explained. A general method to address the relationships between application domains and agent coordination is introduced. This paper also presents a concrete implementation of this idea in the DECAF agent architecture and an initial exploration of the separation of domain action from meta-level coordination actions for eight simple coordination mechanisms.KeywordsMultiagent SystemCoordination MechanismWeak LearnerTask StructureAgent ArchitectureThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.