Realtime Research Of Communication Of Heterogeneous Data In Transport Automation System

Under intense competitive condition, new transport automation system is required to have the online properties, such as on-line expansion, on-line maintenance and fault tolerance, but also required to have two basic properties of real time and reliability.The traditional centralized systematic architecture(such as centralized systematic architecture and client/server systematic architecture) and traditional communication pattern(such as polling and request/reply ) of transport automation system in our country has great obstruction for the real time property of data , so we need to make improvement from two aspects - systematic architecture and communication pattern. This paper analysises respectively from systematic architecture, communication pattern and integrated pattern.The result shows: systematic architecture should adopt the Autonomous Decentralized System(ADS);communication pattern should adopt Publish/Subscribe communication pattern; integrated model should adopt the concept of data field(DF) to realize autonomous system integration. All these selections make transport automation system keep good autonomy and on-line property, and also make the guarantee for the research of real time and reliability of the transport automation system.This paper has analysed the data of different communication property which flow in transport automation system and divided the data into three types,that is, incident data, period data and reliability data, and then have put forward a systematic model to ensure that data of different communication property will not disturb mutually. This system model also guarantee the real time of data transmission. In the proposed model, the most basic characteristic is that the DF of information system and DF of control system respectively divided into three types, that is, realtime datafield , cyclic datafield and reliable datafield . In this kind of model, data of differdnt communication is chosen the communication method in gateway and is sent only to designated purpose data field. This kind of communication method has avoided different communication property data fromdisturb mutully, so, it has raised the real time property of the data.To analysis of the performance improvement of real time of transport automation system,we use queueing theory for the analysis of the traditional transport automation system and the proposed system. The result shows: compare with traditional transport automation system,the proposed system has great improvement in real time property.