密级：公开 基于C8051F020车辆散热系统
参数检测仪的设计
Design of the cooling system parameters of vehicle detector based on C8051F020
学 院： 专 业 班 级： 学 号： 学 生 姓 名： 指 导 教 师：
年 月
摘要
车辆散热系统的参数是车辆安全行驶的保障，其散热系统的稳定性也是衡量车辆先进性的重要标志。因为车辆的各个系统都有一定的参数范围，当各零件的参数都在此范围内时其性能指标才最正常，所以需要很好的监测系统指标的准确性和稳定性，给汽车行业以有力的保障。
当前，我国车辆系统的制造虽已进入自主创新的发展阶段，但由于客观条件的限制，无法长期准确的向工程设计部门提供有效的实车实验数据，严重影响我国车辆总体技术的进一步发展，危害着驾驶者的人身安全。
为了保证在不改变车辆现有结构和性能的前提下，实时监测车辆散热系统的参数，我制作了以单片机C8051F020作为控制核心的车辆散热系统参数检测仪，通过使用DS18B20温度传感器和MPX2100压力传感器，能够准确的获得车辆散热系统的参数，并采用LED实时显示测量的温度和压力，将其与计算机应用软件结合，能够很好的控制参数的范围并采用蜂鸣器来实现报警功能起到预防作用，通过RS-485进行异步串行通信，更好的接收参数信息。
此次车辆散热系统参数检测仪的设计，我查阅了大量的相关资料，制作了较完备的原理图，并且通过编译、调试程序，使系统的性能满足毕业设计的各项要求，整个系统的设计比较成功。
关键词：C8051F020；车辆散热系统；测温；测压
I
Abstract
Parameters of the vehicle cooling system is to protect the safety of vehicles traveling, the stability of its advanced cooling system is also an important indicator to measure the vehicle. Because each system has a certain vehicle parameters, when the parameters of the components are within this range,its performance was the most normal, so the accuracy and stability requires good monitoring system indicators give a strong automotive industry guarantee.
Currently, the manufacture of vehicle systems have entered into the stage of development of independent innovation, but because of objective conditions, it is unable to provide effective long-term accurate experimental data to the real vehicle engineering and design departments, seriously affect the further development of China's overall vehicle technology, hazard the driver's personal safety.
In order to ensure that the vehicle does not change the premise of the existing structure and performance parameters of real-time monitoring of the vehicle's cooling system, I made C8051F020 microcontroller core vehicle cooling system as the control parameter detector by using DS18B20 temperature sensors and pressure sensors MPX2100, which are able to obtain accurate parameters of the vehicle's cooling system , and the use of LED time display of temperature and pressure measurements will be combined with computer applications, which can be a good range of control parameters to achieve using the buzzer alarm function play a preventive role via RS-485 asynchronous serial communication, better reception parameter information.
In order to design the vehicle cooling system parameter monitoring , I read a lot of relevant information,making a more complete schematic,and by compiling, debugging procedures,the system performance to meet graduation requirements designed to compare the overall system design success.
Keywords: C8051F020; vehicles cooling system; temperature; manometry
II
目 录
摘 要 ............................................................................................................................ I Abstract ........................................................................................................................ II 第1章 绪论 ............................................................................................................... 1
1.1 课题研究的背景和意义 .............................................................................. 1 1.2 国内外研究现状及其发展 .......................................................................... 1 1.3 本课题主要研究的内容 .............................................................................. 1 1.4 本章小结 ...................................................................................................... 2 第2章 方案的比较和论证 ....................................................................................... 3
2.1 基于C8051F020车辆散热系统参数检测仪的设计原则 ......................... 3 2.2 本系统所用元器件的选取 .......................................................................... 3
2.2.1 压力传感器的选择 ........................................................................... 3 2.2.2 温度传感器的选择 ............................................................................. 4 2.2.3 即时显示器件的选择 ......................................................................... 5 2.2.4 通信接口的选择 ................................................................................. 6 2.3 总体设计思想 ............................................................................................ 7 2.4 本章小结 ...................................................................................................... 8 第3章 车辆散热系统参数检测仪的硬件电路设计 ............................................... 9
3.1 C8051F020单片机模块介绍 ......................................................................... 9
3.1.1 C8051F020单片机中断系统 .............................................................. 9 3.1.2 C8051F020单片机复位电路 ............................................................ 10 3.1.3 C8051F020单片机端口输入/输出 ................................................... 13 3.2 压力传感器模块 ....................................................................................... 13
3.2.1 MPX2100半导体压力传感器的性能特点 ...................................... 13 3.2.2 差分放大电路的构成 ....................................................................... 14 3.2.3 压力采集模块与单片机的连接 ....................................................... 14 3.3 温度信号采集模块 .................................................................................... 13
3.3.1 DS18B20的性能特点 ....................................................................... 11 3.3.2 DS18B20的测温原理 ....................................................................... 14
III
3.3.3 DS18B20与单片机的连接 ............................................................... 14
3.4 CH451实现扫描驱动和数码显示功能 ................................................... 15
3.4.1 显示驱动功能 ................................................................................... 16
3.4.2 键盘扫描功能 ................................................................................... 17
3.5 报警电路的设计 .......................................................................................... 18
3.6 本章小结 ...................................................................................................... 18 第4章 系统的软件设计 ......................................................................................... 18
4.1 系统主程序流程图 .................................................................................... 19 4.2 压力检测（MPX2100）子程序流程图 ................................................... 21 4.3 温度检测（DS18B20）子程序流程图 .................................................... 21 4.4 键盘扫描和数码显示流程图 .................................................................... 23 4.5 本章小结 .................................................................................................... 24 第5章 结论 ............................................................................................................. 25 参 考 文 献 ............................................................................................................... 26 致 谢 ..................................................................................................................... 26 附 录 ..................................................................................................................... 28
IV