冷库温度测控系统设计.doc

本科生毕业设计（论文） PAGE I 摘 要 介绍了一种基于CAN总线技术的冷库温度控制系统的设计，CAN总线是目前最流行的现场总线技术,它具有可靠性高、价格低廉、实时性强等优点，在自动控制领域广泛应用。 本系统由上位机和下位机两大部分组成。上位机主要完成与PC机的通信功能，由PC机设置及显示各冷库的温度，将设置的温度通过上位机送至下位机，下位机完成对冷库的温度检测以及实现自动恒温控制。上位机与下位机均以AT89S52为核心，下位机使用LED进行温度显示。选用DS18B20单总线数字温度传感器，测量精度可以达到0.5℃。将测量值与设定值进行比较后由下位机控制制冷压缩机或电加热器进行温度调整，达到恒温控制，实现系统智能化。 关键词：单片机；CAN总线；DS18B20；PC机；冷库控制 Abstract The temperature of cold storage control system based on CAN bus technology is introduced in the subject, CAN bus is the most popular fieldbus technology, which has high reliability, low cost, real-time etc.. wider application in the field of the automatic control. The system composed of two major parts consists of upper and lower machine. the main host computer complete the PC-communication functions, it set up and display the temperature of the cold storage by the PC, the temperature will be set up through the lower to the lower machine, the lower machine complete the temperature of cold storage detection and automatic temperature control.AT89S52 is the core of the upper and lower machine, the lower temperature use LED for displaying. DS18B20 is selected for the single-bus digital temperature sensor, the measurement accuracy can reach 0.5 ℃. The measured values will be compared with the set value,after that control the refrigeration compressor or electric heater to adjustment the temperature, achieve the constant temperature control, the intelligent systems is realizated. Key words：MCU；CAN bus；DS18B20；PC；Cold Storage Control 目 录 TOC \o 1-3 \f \h \z HYPERLINK \l _To第1章 绪 论 PAGEREF _To\h 1 HYPERLINK \l _To1.1课题背景 PAGEREF _To\h 1 HYPERLINK \l _To1.2冷库的国内外现状 PAGEREF _To\h 1 HYPERLINK \l _To1.3冷库的发展趋势 PAGEREF _To\h 3 HYPERLINK \l _To第2章 冷库温度测控系统总体设计 PAGEREF _To\h 5 HYPERLINK \l _To2.1课题总体分析 PAGEREF _To\h 5 HYPERLINK \l _To2.2方案论证 PAGEREF _To\h 5 HYPERLINK \l _Toc