| With the rapid development of automobiles, vehicle has become an important products forproduction and life. So people need to find out a more efficient way to manage cars. Sometimes wewish that the information of all the cars can be accessed by the administrators in the same way thatthe vehicle information is accessed by the drivers. Even more we expect to store all the informationin the database so that we can analyze and check the history database, if needed. To meet thisrequirement, we need a device which could obtain kinds of vehicle information, and upload to theserver. Generally, people add sensors or other measuring equipment to obtain more information.But it is noteworthy that a car is an electronic system, which could measure many information bythe so called OBD（On-Board Diagnostics）system of itself.In the design of this paper, firstly the vehicle terminal receive all data from TL718, GPS andRF receiver chip; then package those data into one data packet and upload to servers by using theGPRS module; At last, user could check the car’s information via a browser.In general, the development of a new production is starting with developing modules toachieve sub-functions of the production and then combine them into a whole. So we first introducethe design and implementation of OBD data acquisition module, TPMS module, GPS module,GPRS module and power module; then we introduce the issues occurring in the integration of thosemodules, such as job schedule and resource allocation. At last, we show a view of the user interfaceaccess to the server.The characteristic of this paper is the way to obtain vehicle information, which mainly base onthe data get form OBD system, and also take into account the data get from extra sensors to makeup the shortage of OBD system. After fully analysis of several OBD protocols, we successfulcomplete the OBD data acquisition module by using the TL718as the protocol converter betweenMCU and the car’s OBD interface. Meanwhile, we add Tire Pressure Monitoring system (TPMS)module into the in-vehicle terminal in order to enhance the vehicle’s security, especially thosetractors which do not have a TPMS before they leaves factory. This design takes the full use of carresources first and then adds special sensors to meet requires, thus the device makes a good balancebetween resources and functions.In fact, this paper describes a complete vehicle information acquisition system, includingsteady operation device, wireless communication, and data processing in the server. On the basicsystem, it is easy to change and extend functions. Now, there are two kinds of OBD protocols have already been achieved for the vehicleinformation acquisition system: KW1281, which special used by the Volkswagen and OBD IIstandard protocol. The system has been successfully testified on many cars, such as Bora, Audi,BMW, NISSNA and so on. The testing shows that the design could keep the steady in a longtimeoperation. |
