空调机的温度控制系统设计.doc

空调机的温度控制系统设计







摘要



空调机的温度控制对于工业和日常生活等工程都具有广阔的应用前景。本文将传统控制理论与智能控制理论相结合应用于温度控制的实际工程中。首先，设计出系统的硬件构成，然后，从热力学的角度对温度对象的特性做了较深入的分析，从理论上推导出温度对象的常用的一阶带纯滞后的近似数学模型，并给出了数学模型中各参数的含义。在此基拙上，本文分析了现有空调机控制方法的利弊，并针对它们各自的优、缺点，对具有纯滞后特性的温度对象提出一种改进的模糊控制方法。该方法将模糊控制、PID控制结合起来。通过数字仿真表明该方法对空调机温度的控制具有超调小(可达到无超调)、调节时间短、鲁棒性好等优点。在此基拙上，用阶跃信号做激励，辨识出系统的数学模型。本文的最后，通过对实物实验结果可以看出，本文所提出的改进的模糊控制算法对非线性、具纯滞后环节对象的控制是很有效的。温度控制系统的软件采用汇编语言编制，控制算法部分采用C与汇编混合编程。该软件基于Windows20000/xp平台，人机界面友好，易于用户操作。具有在线修改采样时间、控制算法、控制参数、图形显示及数据保存和打印功能。设计的空调机温度控制的精确性，使用方便，功能齐全。





关键词:PWM控制  模型辨识  模糊控制  PID控制





 





 





 





 Abstract



The thesis studies the Plant of temperature. Firstly，the systeml5 designed and realized. Then the characteristics of temperature of Plant are analyzed inall details from thermodynamics. The approximate mathematics model of temperature plant with one order and dead time is reduced and the meaning of every parameter of this model are expressed, Which is used often and practically in the paper. In addition tot his, we identify the model of the system and the result demonstrated the method is effective for it.



Secondly we analyzed advantages and disadvantages of present control method of temperature. One kind of improved Fuzz-Dahlin control method is presented for Temperature Plant with long dead time and non-linearity. The Dahlin control method, The fuzzy control method are combined in this improved method It is demon strated By digital simulation that the improved Fuzzy-Dahlin makes the extra-regulation more small(even zero), the regulation time more short, and the robustness better for the temperature controlled Plant. It is demonstrated by physical experimentation that improved Fuzzy-Dahlin method presented in this Paper is effective for temperature plant with dead time and non-linearity.



The control software is compiled with visualc++ and matlab .It's easy to use and friendly to the interface of person and machine on the basis of window2000/xpplatform.There are some functions as modify sample time or modify controller's parameters online, display and copy data of temperature curve, and so on. The control hardware is easy to use and its functions are self contained.









Keywords: Intelligent control, model identify, Dahlin control, Fuzzy control, PID control



目录



摘要 I



Abstract - 2 -



目录 - 3 -



前言 - 4 -



1 MCS-51单片机简介 - 8 -



1.1芯片的引脚描述 - 8 -



1.2 MSC-51单片机中央处理器 - 11 -



2 温度控制系统的实现 - 13 -



2.1总体设计 - 13 -



2.2信号采样电路设计 - 14 -



2.2.1温度采样电路设计 - 14 -



2.2.2单片机最小系统的设计 - 16 -



2.3 A/D转换电路设计 - 18 -



2.3.1 A/D转换的常用方法 - 18 -



2.3.2 A/D转换器的主要技术指标 - 19 -



2.3.3 ADC0809的主要特性和内部结构 - 19 -



2.3.4 ADC0809管脚功能及定义 - 20 -



2.3.5 ADC0809与8031的接口电路 - 22 -



2.4软件系统的初始化程序 - 22 -



2.5软件程序的主循环框架 - 23 -



2.6校准程序 - 25 -



3 控制算法的研究 - 27 -



3.1 PID算法的研究 - 27 -



3.2模糊控制系统设计 - 27 -



3.2.1模糊控制算法 - 28 -



3.2.2模糊控制的基本概念 - 29 -



3.2.3模糊控制过程 - 30 -



总结 - 35 -



致谢 - 36 -



参考文献 - 37 -