The Research Of Taxi Meter&Supervising System Based On GPS-GPRS

With the development of society and economy, taxi meets a variety of travel demand by its convenient, fast, and efficient means. Entering the 21st century, with the continuous development of network and informationization technology and the enhancement of people's safety and environment consciousness, it drives the development of taxi monitoring technology. For that reason, the advanced technology of GPS and GPRS is introduced into the taxi monitoring system, which exchange data with the monitoring center to realize the performance of real-time monitoring of taxi, alarming processing, operating scheduling, information release and other functions.In this paper, the writer has investgated the reserach background of taxi monitoring system, also the domestic and international research status of taxi monitoring system, as well as some popular monitoring equptment on the market. Then the overall plan is established by the GPRS networks vehicle monitoring system based on LM3S1138 chips.This system consists of three parts, such as a taxi car terminal, the communication network, and the monitoring center. They joint action to achieve the real-time supervising, operating scheduling, information releasing, and other functions for the center.Firstly, we present three crucial technologies: GPS technology, GPRS technology and embedded technology and specially describe the construction and data transmission mode of GPRS network, pointing out the transmission advantage of GPRS network comparing with traditional GSM network. And the combination of commission and embedded technology is discussed. The composition structure and implementation steps of the system are introduced based on it. At the same time, data transmission communication protocol for on-board end and the monitoning center is given.Then, we primarily discussed the design of mobile terminal. For the design of hardware part, Trimble Copernicus GPS module is adopted as receiver and Huawei GTM900-C module which embed TCP/IP protocol stack as commucnication medium between mobile terminal and monitoring center. And the ARM Cortex-M3 chips are used to perform the task of receving and communication, etc.'For the design of software parts, the programs with C have been finished for the data exchange of GPS and data communication in GTM900-C. VisualC# is used to perform basic functions of PC monitoring software, which can realize the real-time monitoring, storage and inquiry, etc.Finally, the function of the mobile terminal is to make GPS information and the meter data keep communication information unblocked and to realize the data from monitoring center keepping smooth, which can meet the basic needs of users.