基于PLC的温控系统开发

论文编号:ZD898    论文字数:13650,页数:38

 摘  要
 温度是工业对象中主要的被控参数之一，像冶金、机械、食品、化工各类工业中，广泛使用的各种加热炉、热处理炉、反应炉等，对工件的处理温度要求严格控制，因为它直接影响燃烧、化学反应、发酵、烘烤、煅烧、蒸馏、浓度、挤压 成形，结晶以及空气流动等物理和化学过程。随着技术的发展，温度控制系统的组成部分也在变化。本文介绍了以松下PLC为核心的温度控制平台的设计。并介绍了其软、硬件设计的方法和给出了系统的硬件原理图、软件流程图。在该设计中采用热敏电阻对烤箱的温度进行实时精确测量，并将测量出的电压信号送入9089中进行A/D转换，从而进行温度检测。控制部分采用PID控制算法，控制继电器的通断时间，最终实现对烤箱温度的控制。
 
关键字：温度控制 PID控制  A/D转换
  
  
Abstract
   Temperature is one of the main changed parameters in the industrial object, such as metallurgy, machinery, food, chemical industry, and various kinds of furnaces, heat treatment furnaces, reactors which are strict with the temperature processing controlling of workpiece, because it can directly affect on the physical and chemical processing such as burning, chemical reaction, ferment, baking, calcimine, distillation, concentration, extrusion, crystallization, and air flowing. As technology advances, the compositions of the temperature controller are also changed.
This article explains a kind of design of temperature control platform whose core is Panasonic PLC. Besides it introduces the design of software and hardware, and shows the hardware schematic and the flow chart of software. In this design, the thermistor is used to measure the temperature in the oven, and then the measured voltage is sent to 9089 to for A/D transformation. So it can be capable to measure the temperature. The controlling part is uses PID algorithm, by the way of controlling the working time of relay, it can realize the temperature controlling of the oven.
 
Keywords：Temperature control   PID control  A/D Conversion

目 录
摘要………………………………………………………………………………………………Ⅰ
Abstract………………………………………………………………………………………Ⅱ
目录………………………………………………………………………………………………Ⅲ
1  绪论 …………………………………………………………………………………………1
 1.1  背景 ……………………………………………………………………………………1
 1.2  温度智能控制平台的总体概述 ………………………………………………………2
2  系统的硬件设计……………………………………………………………………………3
 2.1  松下PLC介绍………………………………………………………………………3
 2.2 FPΣ及扩展单元详细介绍………………………………………………………………4
 2.2.1  FPΣ…………………………………………………………………………5
 2.2.2  FP∑及模拟量输入模块介绍………………………………………………… 7
    2.3  温度采集电路  ………………………………………………………………………10
 2.4  电热丝控制电路………………………………………………………………………12
3  系统软件设计 …………………………………………………………………………13
 3.1  PID控制简介………………………………………………………………………13
 3.1.1  PID控制的特点………………………………………………………………13
 3.1.2  PID控制原理…………………………………………………………………14
 3.1.3  PID控制算法的设计…………………………………………………………16
 3.1.4  参数的整定……………………………………………………………………18
 3.2 松下编程软件介绍……………………………………………………………………17
 3.3  程序结构图……………………………………………………………………………19
     3.3.1  主程序流程图 ……………………………………………………………… 20
 3.4  程序设计………………………………………………………………………………20
 3.4.1  参数自整定程序………………………………………………………………21
 3.4.2  PID控制程序…………………………………………………………………23
 3.4.3  继电器控制程序………………………………………………………………24
4  温控系统平台  …………………………………………………………………25
 4.1  温度采集电路  ………………………………………………………………………25
 4.2  PLC连接电路  ………………………………………………………………………25
 4.3  电热丝控制电路  ……………………………………………………………………26
 4.4  电热丝  ………………………………………………………………………………26
 4.5  温控系统整体  ………………………………………………………………………27
5  总结…………………………………………………………………………………………28
致谢………………………………………………………………………………………………29
参考文献 ………………………………………………………………………………………30
附录1  主要程序……………………………………………………………………………31