【作者】 高锋；

【导师】 黄东；

【作者基本信息】 东南大学 ， 控制工程， 2015， 硕士

【摘要】 伴随着国内经济的快速发展,出租车已经成为城市公共交通中不可或缺的一部分,与人们的生活息息相关。出租车费用的计算则需要计价器,但其可能会存在着作弊行为,损害乘客的利益,为此要求计价器具有反作弊功能的呼声越来越高。本文首先介绍了出租车计价器的工作原理,分析几种作弊方法,得出其主要作弊方法。在分析正常计价信号脉冲特点的基础上,得出正常计价信号与作弊信号脉冲之间的差别,并将此作为计价器反作弊系统的工作原理。依据该工作原理本文提出了两段式数据传输的计价器反作弊系统,由车载数据采集系统,中继系统和综合管理系统组成。通过比较研究对系统选取了无线通信模块来实现系统的短距离通信,选取GPRS作为系统的远距离通信方案,选取单片机作为系统的主控芯片。设计了系统的硬件结构,对车载数据采集系统重点介绍了AT89C52单片机、LM324运算放大器、短距信号发射、接收模块,并给出了车载数据采集系统的的原理图。对固定查询系统主要介绍了其GPRS模块G200,研究了该模块的调试过程。对综合管理系统,主要研究了G200模块与PC机之间的连接,采用TTL-RS485连接线来实现电平的转换。设计了系统中的软件部分,主要包括数据的传输格式、编码格式的设计和数据发送、接收子程序和判断计价器是否作弊主程序。对该系统进行了实验室测试和实际运用的测试,测试表明,该系统能够实现预期的目标,且具有可靠性较高,使用方便,成本低等优点。更多还原

【Abstract】 With the developing of economic the taxi has become an important part in city public transportation and closely linked to people’s daily life. Calcualting of the taxi riding cost need the meter. But it may exist cheating and damage the interests of passengers. So more and more people require the meter have the function of examination cheating.This paper firstly introudce the working principle of taximeter. Analising some cheating way in taximeter and getting the main way. By analysing the feature of mormal pulse and getting the difference between the cheating pulse and normal pulse. According the dirrerence to distinguish the taximeter is cheating or not.According to the working principle, this paper propose a two stage data transmission system which composed by board data acquisition systm, relaying system and integrated management system. By comparing research, the wireless communication mode and GPRS to achieve the fuction of data transmission were choosen. Using SCM as the main control chip.Designing the hardware of the system. Highlighting the AT89C52,LM324, short-range signal transmission and receiving module. Then show the schematics of the board data acquisition systm. This paper maily introudce the G200 module in the relay system. For the integrated management system, this paper using TTL-RS485 to convert the voltage level between the G200 and PC.Designing the software in the system. Inculding the data transmission format, encoding format, the subroutine of data transmission or reception and the main program to determining the taximeter is cheating or not.The system was tested in laboratory and practical use. The results show that the system can achieve the desired obiectives and have the advantages of high reliability, ease of use, low cost, and so on.更多还原