SEMANTIC AGENT-BASED CONTROLS IN SERVICE ORIENTED ARCHITECTURE (SOA) ENABLED INTELLIGENT TRANSPORTATION SYSTEMS (ITS

摘要

Intelligent Transportation Systems (ITS) have been considered as a solution to the problemsassociated with modern urban traffic management systems. The implementation of ITS is highlycomplex due to the multi-domain and geographically distributed nature of the trafficcontrols/systems and legacy infrastructures. Some of the approaches that have attempted to addressthese challenges include control engineering, artificial intelligence, telematics, grid computing andmulti-agent systems. This research work was undertaken to investigate the implementationapproaches aimed at addressing the complexity and communication challenges of ITS, specificallyintelligent and cooperative traffic systems/controls which are capable of distributed decision makingin response to emergent traffic situations.This research introduces the novel concept of Semantic Agent-based Controls which utilise a uniquecombination of computing concepts including multi-agent systems, Service Oriented Architecture(SOA) and semantic web services. The semantic agent-based controls extend the functionality anddecision making capabilities of fixed traffic controls by using semantic agents over the network toeffectively control geographically distributed traffic controls/roadside systems.The research introduces a novel Agent communication and coordination mechanism that facilitatesthe interaction between the Semantic Agent-based Controls in a multi-domain ITS environment. Themechanism uses a semantic layer approach based on the principles of SOA and the concept ofsemantic web services which enables Agents to store, share and integrate heterogeneous data on thesemantic level across the SOA enabled network of traffic systems and devices. This highly flexiblemechanism allows semantic agent-based controls to interact with each other by using different levelsof ontologies that semantically describe the Agents’ intentions, behaviours and coordinationstrategies. The semantic communication layer allows coordination of action plans in the form ofdecision rules between the semantic agent-based controls which facilitates dynamic and distributeddecision making in response to emergent situations.A new ITS platform (named ITS@CU) is presented, which was developed to support and evaluatethe semantic agent-based controls approach. The ITS@CU platform (and the associated simulationutilities) was developed using the latest state of the art commercially available tools and technologies.It is a multi-agent platform and is based on advanced SOA principles which enable seamlessintegration of traffic controls/systems.4The research approaches are evaluated using a variety of different test cases generated usinghistorical traffic data and typical traffic situations identified by UTMC Control Room, Coventry CityCouncil. The results demonstrate the advantages of Semantic Agent-based Controls especially whencompared with traditional controls (without Agents). The advantages include communicationreductions, flexible and robust coordination between the distributed controls, and enhanced decisionmaking and self-organisation capabilities.The research presented started as a Knowledge Transfer Programme (KTP) funded project incollaboration with T@lecom Limited. Elements of the ITS@CU platform developed during theproject also led to the design and development of the following three successful commercialapplications/products for T@lecom. The “Patient Transport System” is a mobile solution forambulance crews to transfer patients to and from hospitals and with novel features of intelligenttracking, two-way messaging/alerts and patient prioritising in real-time. The “Mobile GatewaySystem” is a SOA enabled unified communication and integration platform for T@lecom’s mobilesolutions. Finally, the “Vehicle Tracking Solution” incorporated comprehensive functionalities of theITS@CU platform and also includes a novel driver behaviour assessment.