智能数字温度测控仪表的设计

电气自动化论文编号:ZD634    论文字数:23678,页数:52 

目录
摘要…… I
Abstract II

第1章 绪论 1
1.1 课题背景 1
1.2 课题的提出和意义 1
1.3 工业温度控制的发展标题 1
1.4 温度微机控制系统控制方案概述 2
1.5 设计任务 3
第2章 硬件电路的设计 5
2.1 总体方案 5
2.2 单片机的选择 5
2.2.1单片机的简述 5
2.2.2单片机的选择 6
2.3 温度测量与放大电路 8
2.3.1铂电阻的工作特性和分度简表 9
2.3.2热电偶的工作特性和分度简表 11
2.3.3 冷端温度补偿 12
2.4 电压/频率转换电路 13
2.5 温度控制电路 14
2.6 报警电路 17
2.7 按键和显示电路 18
2.8 通信电路 19
2.9 电源电路 21
2.10 本章小结 21
第3章 PID控制策略及仿真分析 22
3.1 采用PID控制算法的原因 22
3.2 PID参数的作用 23
3.3 被控对象 24
3.4 PID控制方法 24
3.5 仿真分析 26
3.5.1 仿真工具 26
3.5.2 仿真环境Simulink 26
3.5.3 系统PID控制仿真 27
3.6 本章小结 29
第4章 系统的软件设计 30
结论 32
致谢 33
参考文献 34
附录A 36
附录B 44

摘要
 温度是工业控制的主要被控参数之一，如在冶金、机械、食品、化工、印染、石油加工等工业中，广泛使用的各种加热炉、热处理炉、反应炉等对工件的处理温度都要求严格控制，对于温度的精确度和稳定性均有较高的要求。
 本次设计的智能数字温度测控仪表硬件设计选用了以AT89S52单片机为核心的控制芯片，配合热电阻、热电偶温度传感器进行温度检测，同时由过零触发光电耦合器件MOC3021和晶闸管构成驱动执行单元，由按键、LED数码显示器及报警单元等组成人机联系电路，此系统还设计了单片机与上位机的通信，实现了远程温度控制。
 由于温度自身具有惯性大，滞后现象严重的特点，文中用MATLAB软件对电烤箱这样一个被控对象进行PID 控制及仿真分析，仿真结果表明，PID控制基本上能达到相应速度快、超调较小、稳态误差为零的效果。
 
关键词　单片机；温度测量；信号转换；温度控制；报警
 The design of intelligent digital temperature control instrumentation
Abstract
 Temperature is one of the main parameters of which in industry control, such as in metallurgy, machinery, foodstuffs, chemicals, printing and dyeing, oil processing industry. In the wider use of various furnaces, heat treatment furnace, the reactor and other parts, the temperature is required strictly to control, and temperature accuracy and stability have higher requirements.
 The hardware design of intelligent digital temperature control instrumentation chosen AT89S52 micro controller as the core of the control chip, able to cope with heat resistance, such as linear transmitter thermocouple temperature sensor to detect temperature, and from zero to trigger light MOC3021 coupled device, and the implementation drive unit, keys, LED digital display and alarm unit composed of human computer link circuit, this system also designed the MCU and PC communications, to achieve a long-range temperature control .
 As the temperature of owning the characteristics of phenomenon seriously lagging behind as to electronic oven, the PID control were applied and the simulation analysis was comparatively made. Simulation results show that, PID control can basically meet the corresponding speed, overshoot smaller, the effect of steady-state error to zero.
Keywords　MCU; temperature measurement ;signal converters ;temperature control;  alarm