基于FPGA的出租车计费器设计毕业设计(论文).doc

基于FPGA的出租车计费系统设计 华东交通大学毕设计 PAGE 60 PAGE 61 基于FPGA的出租车计费系统的设计 摘要 随着我国市场经济的发展，交通也越来越便利，特别是计程车，以快捷、方便的特点早已盛行各个城市，成为城市交通的重要工具。计程车市场从90年代初的起步阶段到现在已经进入了高峰期。随着城市化水平的提高和人民生活水平的改善，计程车的服务也就显得越来越重要。因此计程车计价器也就应运而生了。 本文分析了当前国内外出租车计费系统的基本组成和工作原理及主要的两种设计方式:基于单片机的设计方式和基于FPGA的设计方式；并对这两种实现方式的优点和缺点进行分析，比较后确定本系统的方案：基于FPGA的出租车计费系统的设计。 在本设计中主要是通过VHDL语言来编程实现计费系统的四个功能块：分频模块，控制模块，计量模块和译码显示模块，最后使用MAX+PLUSII软件来对程序进行仿真，以模拟实现出租车的启动，停止以及等待等过程中的计时，计程和计费功能。并将各功能模块的结果通过动态译码扫描模块输出到显示模块进行显示。即通过显示模块显示出租车所行驶的路程，出租车等待的时间和出租车分别在等待过程中的费用和行驶过程中的费用。 关键字:CPLD/FPGA；VHDL语言；MAXPLUS II；出租车；计费器 Design of taxi meter Based on FPGA Abstract As Chinas market economy develops，more and more convenient transport，particularly taxis, to fast, convenient features have long been popular in various cities and become an important tool for urban traffic. Taxi market in the early 1990s,the initial stage up to now has entered a peak period. With the level of urbanization and the improvement of peoples living standards improve, taxi services will become increasingly important. Taxi meter therefore it has emerged. This paper analyses the current domestic and foreign taxi billing system and the basic working principle and the two main design; Based on the design of microcontroller and FPGA-based design; and both the strengths and the ways Shortcomings of the analysis，comparison of the system established after the programme: FPGA-based billing system for taxis. In this design mainly through the VHDL language programming billing systems of the four function blocks：the frequency modules, control module, the measurement modules and decoding modules, the final use of MAX + PLUSII software to simulate the procedures to Simulation of the realization of a taxi start, stop and wait in the course of time, and so on, including-and billing functions。And the results of the functional modules through dynamic decoding scanning module output to display module to display it. Through the display module Taxis By the travelling distance, a taxi wait