Design And Virtual Implementation Of Vehicle Positioning System Based On GPS/GSM Short Message

With the rapid development of market economy, many problems in the traffic management, such as the heavy traffic, ever increasing accidents and car robbery, have emerged due to the fact that the growth rate of private cars in the cities is faster than that of the road construction. Thus, it is significant that how to utilize the technologies existed to solve the above problems.A good resolution is offered to settle the problems mentioned above based on GPS/GSM vehicle monitoring system. In this system, the vehicle location is accomplished by the GPS module carried by the vehicle, before the information of the location is sent to the monitor centre by the GSM module, it is needed to be preprocessed by the control module, the monitoring centre, along with the GIS system, sends the control commands to the vehicle terminal after the analysis of the location information.Firstly, the developments of vehicle monitoring system and the principles of the system are presented, including the composition of GPS system, the structure of the signals, the principle of positioning and the location error. By the comparison among several wireless communication protocols in the vehicle location system, GSM message service is selected to serve as the ultimate solution to communication. Secondly, particular intention is paid on the technologies relevant to GSM communication. Design of the vehicle terminal is discussed from the practical point of view. Based on the analysis of the GPS module, GSM module and ARM main control module, the basic functions of the vehicle terminal are realized by using the programs compiled. Finally, a simulative monitoring centre is completed utilizing VC6.0.Debugging results show that the vehicle terminal can transmit the location information from the GPS module to the monitoring center in the form of message, and can receive the control commands from the monitoring centre. The simulated monitoring centre takes in charge of the analysis of the location information sent from the vehicle terminal and sending the effective information, such as longitude and latitude, time, speed, course, etc., back to the vehicle. Thus, duplex communication between vehicle and monitoring centre is accomplished.