Coordinated constraint relaxation using a distributed agent protocol

• Main Author: Hassan, Mohd Fadzil
• Published: University of Edinburgh 2007
• Subjects: 519
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.652216

The interactions among agents in a multi-agent system for coordinating a distributed problem-solving task can be complex, as the distinct sub-problems of the individual agents are interdependent. A distributed protocol provides the necessary framework for specifying these interactions. The foundations of this work are the Lightweight Coordination Calculus (LCC) and the distributed partial Constraint Satisfaction Problem (CSP). LCC is a distributed interaction protocol framework, based on process calculus, for specifying and executing agents’ social norms in a multi-agent system. Distributed partial CSP is an extension of distributed CSP, a scheme of managing the relaxation of distributed, over-constrained, CSPs. Hence, the research work presented in this thesis concerns how the distributed partial CSP technique, used to address over-constrained problems in the constraint satisfaction field, could be adopted and integrated within the LCC interaction protocol framework, to obtain a more flexible means of constraint handling during agent interactions. The approach is evaluated using a Multi-agent Agreement Problem (MAP) with different degrees of constraint densities and tightness. Not only does this thesis explore a flexible and novel approach of handling constraints within the agents interaction domain, but it is also grounded in a practical implementation.