湖南文理学院
课程设计报告
课程名称： 嵌入式系统课程设计 专业班级： 自动化 学生姓名： 指导教师： 完成时间： 2013年 7 月 1 日 报告成绩：
湖南文理学院制
评阅意见： 评阅教师 日期 2013.7.5
摘 要
汽车的制动性能是汽车性能的重要指标之一，是汽车检测中的重要项目。目前制动性能检测有台架法和路试法，台架法虽然被广泛使用，但是由于其检测结果不能完全反应汽车实际制动过程中的运动变化，存在一定的缺陷。而路试法能确切的检测汽车道路行驶制动的性能。随着计算机技术的飞速发展，越来越多的融入先进技术的便携式道路制动性能测试系统被研制出来。
本文介绍了GB7258-2004《机动车运行安全技术条件》对路试法检测制动性能的测试标准和测试内容的规定，分析了行车制动的过程，提出了测试各运动量的测试方法。基于这些测试方法设计了一种基于路试法检测汽车制动性能的测试系统。该系统采用目前先进的嵌入式软硬件技术，设计了采集和处理试验数据的ARM系统。ARM系统部分以ARM7内核的微处理器LPC2294为核心，扩展了键盘、液晶显示、试验数据存储、USB接口等硬件模块，通过A/D和定时器捕获等功能接口，采集来自ARM系统前端的非接触式传感器的车速信号和制动踏板力信号，处理后的数据可以在液晶上显示出来，存储在数据存储单元，同时也可以通过USB接口将采集和计算的各种数据传送到上位机中。设计了上位机上对制动性能分析与评价软件，它可以绘制出制动过程中的速度-时间等曲线，并对制动性能做出评价。
关键词：汽车；制动性能；ARM；μC/OS-Π
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Abstract
The automobile braking performance is one of the important guidelines automobile performance and an absolutely necessarily in automobile inspect. At present there are two kinds of methods to check braking performance. The one is Roller test method and the other is Road test. Although norms method is used extensively. But because of its detection result can not fully reflect the actual process of sports car brake changes. Along with the rapid development of computer technology, more and more into the advanced technology of portable road braking performance test system were developed.
This paper introduces the GB7258-2004 \vehicle safety operation technology conditions of automobi ShiFa detection braking performance testing standards and test content regulation, analyzes the process of crane brake, puts forward the testing all level of test method. Based on these tests designed a kind of ShiFa detection based on road car brake performance test system, Puts forward testing all level of test method. Based on these tests designed a kind of ShiFa detection based on road car brake performance test system. The ARM system of the kernel's microprocessor ARM7 LPC2294 as the core, expanded the keyboard, LCD display, test data storage, USB interface hardware modules, through A/D and timer function such as interface, collection, captured from ARM system's front-end non-contact sensor speed signal and the brake pedal force signal, the processed data can be displayed on the LCD, storage in data storage cell, can also use USB interface will collection and calculation of various transfer data to the upper machine. Design of the upper machine braking performance analysis and evaluation software, it can draw the braking process of speed - such as time of braking performance curve, and make comments.
Keywords: Car, The braking performance, ARM, UC/OS-Π
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目 录
摘 要 .............................................................................................................................................. I Abstract .......................................................................................................................................... II 一、设计题目 ................................................................................................................................. 1
1.1 汽车制动性能检测技术发展 ......................................................................................... 1
1.1.1 制动控制系统的历史 ........................................................................................... 1 1.1.2 制动控制系统的现状 ........................................................................................... 2 1.1.3 制动控制系统的发展 ........................................................................................... 2 1.1.4 全电路制动(BBW) ............................................................................................... 3 1.1.5 结论 ....................................................................................................................... 3 1.2 设计要求 ......................................................................................................................... 4 二、汽车制动性能测试方法 ......................................................................................................... 4
2.1 制动过程分析 ................................................................................................................. 4 2.2 测试标准与测试内容 ..................................................................................................... 5
2.2.1 制动距离检测行车制动性能标准 ....................................................................... 5 2.2.2 充分发出的平均减速度检验行车制动性能标准 ............................................... 5
三、系统硬件部分设计 ................................................................................................................. 6
3.1 系统硬件部分总体设计 ................................................................................................. 6 3.2 传感器信号调理 ............................................................................................................. 6 3.3 ARM微处理器LPC2294 .............................................................................................. 7 3.4 系统电源电路 ................................................................................................................. 8 3.5 复位晶振电路 ................................................................................................................. 8 3.6 键盘扩展电路 ................................................................................................................. 9
3.6.1 特点 ....................................................................................................................... 9 3.6.2 功能描述 ............................................................................................................. 10
四、系统软件部分设计 ............................................................................................................... 11
4.1 系统软件总体设计 ....................................................................................................... 11 4.2 ARM微处理器与上位计算机串行通信 ..................................................................... 12 4.3 程序流程图 ................................................................................................................... 14 五、测试结果 ............................................................................................................................... 14 六、总结 ....................................................................................................................................... 15 参考文献 ....................................................................................................................................... 16 致 谢 ........................................................................................................................................... 17
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