Intelligent traffic information sharing technology based on the Internet of Things

T-Grid is a universal information resource sharing platform that integrates Internet and distributed system technologies, and fully complies with the concept of Internet of Things technology. Its main goal is to establish a compatible environment so that various distributed traffic information resources can be scheduled and used with a unified interface. Under the T-Grid framework, all accessed devices (resources) have basic data processing capabilities.

The grid computing adopted by Hu Songlin et al. and Li Wei et al. is the agent architecture model. Through the analysis of the functions of each entity node in the field of traffic management system in 1.1, the following objects and corresponding relationships are further summarized (see Table 2). The mobile node (node ​​E), field node (C) and control node (B) are described as subclasses of T-Agent.

We can see from the above description the objects that make up T-Grid:

Messaging Objects

1.2.1 Message Passing Object (MEX)

That is, the message bus determined by the connector class. The message bus is the basis of proxy grid computing. The basis of the message bus is XML-based message exchange. Through a unified message communication method and a unified message exchange format, various applications or systems are connected to the message bus to exchange data or other information with each other. The message bus structure based on message exchange effectively connects different business systems (or application systems) to the message bus, which is the basis for the business process management system to integrate different businesses. An extensible message exchange standard based on XML[6][7] can be used to define the T-Grid message specification. Figure 5 is a schematic diagram of the message bus of the T-Grid platform.

In T-Grid, from a standardization perspective, we use the instruction and data encoding standards established by the NTCIP protocol to manage these basic I/O objects.

1.2.2 Data I/O Object (T-MUX)

T-Grid divides the hardware characteristics into five basic I/O objects: display class, operation class, storage class, input class and control class. Each basic class can be completely independently controlled by its corresponding instruction set. In this way, everything from a super-large instrument to a simple sensor can become a shared target. Each front-end T-Node processes the data through the corresponding data processing algorithm. First, it filters the noise of the data and second, it performs necessary data association preprocessing on the original data. The processing of independent data source traffic data is completed here. After the data of many detectors are uploaded to the center, the central system platform will perform relevant information fusion work on this basis.

1.2.3 Data Control Object (T-Agent)

The implementation of applications in T-Grid is the result of the interaction between T-MUX and T-Agent through basic communication objects. T-Agent is a responsive, autonomous, internally driven entity. Although it is in a changing environment, it can perceive and respond to it; and T-MUX is the direct action object of T-Agent. T-Agents are connected and can be accessed directly. T-MUX is also a responsive, autonomous, internally driven entity, but T-MUX does not perceive and understand the environment by itself. It responds only after being accessed. Moreover, T-MUXs are independent and cannot directly access each other.

1.2.4 Grid Application Control (C-Agent)

We regard Node B in the traffic management system as the controller in the agent system and also the application control in T-Grid. The T-Grid model is different from the original traffic system in terms of resource integration. It should achieve two aspects of integration: T-Agent uses the NTCIP protocol to call the functions of T-MUX and collect data. On the other hand, T-Agent should be able to integrate with the new and old system-level (NodeA and NodeB) resources through the message bus. The agent generally exists in the form of a software program running on a high-performance computing device. Agent is the most critical part of T-Grid. It effectively manages and schedules various T-MUX and systems in a distributed state, and provides efficient, safe and reliable services for applications.

2. System operation mechanism

Under the concept of the Internet of Things, shared resources and collaborative network services are the essential characteristics of the grid. The goal of the functional composition and distribution of the traffic management system is to reasonably distribute the functions of the entire system in data collection, information processing and information release among five different types of nodes, and work together to complete the functions of the traffic management system. The system is divided into three levels: 1) Central information processing platform. The main function of the central intelligent agent is to realize the information integration of the entire system. It manages, coordinates and controls the entire system through the central database and method library. 2) Intelligent agent node platform. The intelligent agent node includes a data collection unit, an execution module, a processing module, an independent database, a specific method library and a coordination communication unit. 3) Existing basic traffic information collection units and traffic control units.

In the T-Grid operation mechanism model (see Figure 6), T-MUX represents the underlying object service, and Agent represents the control mechanism of the data flow. When using a function, the user does not directly face the provider of the function, but indirectly accesses it through an agent mechanism, which allows a user to call multiple service providers of the same type to work at the same time. Its advantage is that the efficiency of the system no longer depends only on the performance of a single service interface. The system has the ability to process in parallel, and its fault tolerance is significantly enhanced. When a service interface fails, the Agent can transfer the call to another interface of the same type without causing the application to crash. At the same time, both T-MUX and Agent in T-Grid have "plug and play" capabilities. T-Grid changes the original scope of resources. T-MUX is a basic I/O object, and Agent calls and processes the functions of T-MUX through basic communication objects.