Research On GPS/GPRS Vehicle Location Network System And Online Fault Detection Technology

This paper,we have a detailed study about the main technologies involved in GPS/GPRS vehicle location network system, designed GPS/GPRS vehicle location network system, and describe the specific realization of technical principles to the three components of the system. At the same time, The operation failures of GPS/GPRS vehicle location network in the three components of the system has been studied in this paper,too. Fault detection methods and techniques about GPS/GPRS vehicle location network system also been put forward, realized fast fault detection and exclusion in running of the system, ensured the system’s stability and efficient operation of the system.Using the GPS vehicle positioning terminals which based on GPRS, combining with Internet technology and GIS technology, we can locate the vehicle tracking on the Internet, and bring out tremendous convenience and high economy returns for the vehicle location using unit on the management.Currently, it’s very popular to use GPS/GPRS vehicle network location system in the vehicle location management and applications, and the application is very wide. Meanwhile, a lot of problems and failures appeared in the use of GPS/GPRS vehicle location network system, brought a lot of trouble for vehicular use and management. For this reason, China FAW Group Corporation which operating more than 30,000 vehicles put the design of the GPS/GPRS vehicle location network system and online fault detection as an important issue to study. Design the GPS/GPRS vehicle location network system, grasp the overall structure principle of the system, carefully analysis the implementation of the related technology of every parts, and give a systematic analysis to the failure mechanism of the various parts of the system and implement rapid and efficient online fault detection research is the the main research contents of this article. Finally, experiment test the feasibility of the system design,and verify the effectiveness of the fault line detection.First, this paper studied the principles of the Internet TCP/IP protocol, designed GPS/GPRS vehicle location network system, and divided the overall structure of the system into three components:GIS network workstations, network communications server and GPRS vehicle position terminal, it’s relatively independent of these three parts on the concrete realization, at the same time a whole GPS vehicle location network system can be constitute through the Internet technology and wireless networking technology.Then, studied the main relevant technical principles of these three components of the system, expounded GIS network workstations, network communication servers and the design principle of GPS/GPRS Vehicle Location terminal,also studied the the problems which may caused by variety of failures of three components of the system during operation, and gave the corresponding fault online detection methods.First,From the description of GIS spatial data, GIS spatial data entry and processing, GIS spatial data management and GIS geographic information visualization these four areas, we studied the principles of GIS technology, combined with Internet technology, designed the GIS network workstations to transform the GPS location coordinates into vehicle icon of the corresponding position on the electronic map; We studied the GIS network workstations communication fault detection methods and techniques, presented technology which regularly send TCP packets to the network communications servers to detect TCP network connection status, solved the problem of the TCP connection status online fault detection between the GIS network workstation and network communications.GIS network workstation is a client-side man-machine interface procedures mainly GIS application, based on internet TCP/IP communication, in the system work as a network communications server client, there are two servers using the TCP protocol SOCKET communication link between network communications, and all based on Internet transmission.One is used to send the "Set GPS positioning data return interval "command to the network communications server, to Set GPS/GPRS Vehicle Location terminal and timing return GPS positioning packets. The other one is to receive the GPS location data packets for real-time from the network communications server. GIS network workstation is responsible to parse the GPS positioning data packet received, showing vehicle in the form of the icon on the corresponding position in the electronic map. During the GIS workstation operation, these two links will come out network communication failures for various reasons, make the GIS network workstations can not operate normally. To this end, this paper presents TCP network connection state detection technology which regularly sends TCP network data packets to the network communications server, to achieve the network state fault detection between the GIS network workstation and network communications server. Use the technology which regularly send TCP network data packets to the network communications server, to determine whether the network connection status is normal in the shortest possible time 30 seconds between the GIS network workstation and network communications server, provided a good practical technical means for the fault detection and resolution to GIS network communication network workstations.Second.This paper give a research about the network communication protocol based on TCP network services principle, design network communications servers based on TCP protocol, achieve the instruction set about the GIS network workstations communication and real-time data communications services, GPS/GPRS Vehicle Location positioning terminal instruction set and Data Return’s communication services; Study the fault detection methods and techniques of the network communications server communication, raise using the DOS command TELNET method tools to detect whether the services are in the normal interception state and the technology which regularly query data packet’s time interval of every TCP online connection to detect line connection state.Network communications server is the core communication of the whole system that contains three sub-services, and they all based on TCP protocol SOCKET communications services. The first sub-service is instruction receive services, to receive the settings instructions sent from the GIS network workstations; The second sub-service is the real-time GPS positioning data distribution services, it used to send real-time GPS positioning data packets to the GIS network workstations; The third sub- service is GPS/GPRS vehicle location terminal communications services, to communicate with the GPS/GPRS Vehicle location terminal, to send set commands to GPRS vehicle positioning terminal, at the same time receive GPS positioning packets returned by GPRS Vehicle location terminal. The three sub-services of the network communication server may cause some listening failures by various reasons during running, Meanwhile, the connectivity which already in the state of communications may also cause exceptional failures due to various complicated communication. For this reason, this paper presents TELNET method to detect whether the services are in the normal interception state and the technology which regularly query data packet’s time interval of every TCP online connection to detect line connection state. Using the DOS command TELNET method tools to detect whether the services are in the normal interception state, can determine whether the service port is normal in the shortest possible time 30 seconds. Regularly query all the send and receive time interval of the TCP online connection packets, compare the inquiry results with set the time interval, to determine whether the TCP online connection state is normal, it is extremely fast, in the network communication server program, can be completed within the milli-second level time.Studied the GPS positioning technology and mobile wireless communication technology, designed GPS/GPRS Vehicle Location terminals, achieved the reading of GPS positioning data and sending GPS location data packets through the GPRS wireless network to network communications server to send; studied the fault of GPS/GPRS Vehicle positioning terminal in communications and location.Third.GPRS Vehicle Location terminal is GPS positioning devices which installed in the vehicle based on GPRS module communication, have GPRS communication module. GPS positioning module and integrated circuit boards inside, GPRS antenna and GPS antenna external. GPRS module connected to the Internet through CMNET way, as a client of network communications server, it use the SOCKET communication based on TCP protocol, receive set instructions sent from network communications server, and send GPS positioning data collected by GPS module to network communications servers. As the terminal equipment is installed in the car, move with the car, network conditions are very complex and also the most prone to cause network anomaly component. Presented in this paper, there are three ways which detect the GPRS Vehicle Location terminal fault line online can quickly locate equipment faults, provide an effective technical basis for effectively rule out the GPRS Vehicle Location terminal failure, make the GPRS Vehicle Location terminal return to normal working condition.Fourth, GPS location data packets were sent upstream and the "end-time vehicle positioning settings GPRS GPS location data return time interval command" packet downlink two experiments, indicating that the terminal using GPRS vehicle positioning, combined with Internet technology and GIS technology, in location and tracking of vehicles online, not only in theory, but in practice proved to be feasible. At the same time GPS GPRS vehicle location network system fault line detection experiment to test the effectiveness of the fault line detection. Using this system, we can in a very short period of time for the dynamic location information of vehicles, to facilitate quick management and scheduling of vehicles to provide a technical basis.In this paper, GPS/GPRS vehicle location network system mainly involved a detailed study of relevant technology, the design of the GPS/GPRS vehicle location network system, and the three components of the system to achieve specific technical principles are described. Meanwhile, this paper GPS/GPRS vehicle location network system of the three components of the operational failure were studied, proposed GPS/GPRS vehicle location network system fault detection methods and techniques to achieve the system is running in the fast fault detection and excluded, to ensure the stability of the system work and efficient operation.