Control Aspects in Multiagent Systems

Abstract

The work described in this chapter develops a control framework for modelling, analysis and execution of parallel/distributedtime-dependent multi-agent systems. The goal is to clearly separate agent behaviours from crosscutting control concerns which in general are orthogonal to a specific application and transparently affect and regulate its evolution. The approach centres on a minimal computational model based on actors with asynchronous message-passing and actions. Actors are the basic building blocks for modelling the business logic of an application. Actions model activities needed by actors, which have a time duration and require specific computing resources to be executed. Action execution can be either preemptable or not preemptable. Actions are the only abstraction units which have to be reified when passing from model analysis to model implementation. Therefore, the use of actions favours model continuity, i.e., a seamless transformation from model analysis by simulation to model implementation and real time execution. Different pluggable control strategies ranging from pure concurrent to time sensitive (real-time or simulated-time) were implemented. Control strategies are compliant with agent mobility and resource availability. For demonstration purposes, the realized control framework was tailored to the JADE distributed agent infrastructure. This chapter first describes the control framework and its prototyping in JADE. Then presents two case studies. The first one is devoted to a thorough assessment of the timing behaviour and performance of a company help desk system. The second one is concerned with the schedulability analysis of a real-time tasking set. Finally, directions of on-going and future work are drawn in the conclusions.