液晶玻璃窑炉温度前馈模糊PID控制方法研究

发布时间：2018-06-16 04:32

本文选题：液晶玻璃 + 窑炉　；参考：《郑州大学》2017年硕士论文

【摘要】：液晶玻璃基板透光度好、厚度薄、纯度高,其生产过程对工艺温度要求极高,温度控制的调节时间和稳态精度都会影响产品的质量。所以,液晶玻璃窑炉温度控制要比传统玻璃窑炉温度控制更复杂。液晶玻璃窑炉的温度控制系统是非线性、大滞后、难建模的控制系统。传统的液晶玻璃窑炉采用PID控制方式,玻璃容易产生气泡、条纹等质量问题。本文以液晶玻璃窑炉为研究对象,目的是设计一种有效的控制方式,使系统具有超调量小、稳定性好、调节时间短、稳态误差小、可以有效抵抗耦合干扰的优点。在窑炉加热方式选择上,本文选择了燃气燃烧加热和电助熔加热两种结合的混合加热方式,阐述了两种加热方式的温度控制回路。在温度控制方法研究上,本文将传统的PID控制方法与模糊控制方法相结合,并加入了前馈控制,设计出一种带前馈的模糊PID控制算法。这种控制算法既具有PID控制稳态误差小的特点,还具有模糊控制超调量小的特点,加入前馈缩短了对干扰的调节时间,减小了稳态误差。本文的主要研究内容如下:(1)分析了液晶玻璃窑炉加热方式和温度控制对产品质量的影响,对国内外相关研究的现状进行了综述。(2)分析了液晶玻璃生产的工艺和液晶玻璃窑炉温度控制的核心地位。(3)重点分析了液晶玻璃窑炉温度控制方案。确定了前馈-反馈控制器结构,给出了带前馈的温度控制方框图。(4)研究了模糊PID控制算法。将PID控制与模糊控制相结合,设计了模糊PID控制算法,并完成了模糊PID控制在PLC上的实现。(5)通过仿真实验对PID控制、模糊PID控制以及带前馈的模糊PID控制方法在液晶玻璃窑炉温度控制的效果进行了分析研究,结果表明:带前馈的模糊PID控制方法具有超调量小、稳态精度高、抗干扰能力强的综合优势。
[Abstract]:Liquid crystal glass substrate has good transmittance, thin thickness and high purity. Its production process requires very high process temperature. The adjusting time and steady state precision of temperature control will affect the quality of the product. Therefore, liquid crystal glass furnace temperature control is more complex than traditional glass kiln temperature control. The temperature control system of liquid crystal glass kiln is nonlinear, long lag and difficult to model. Traditional liquid crystal glass kiln adopts pid control method, glass is easy to produce bubble, stripe and other quality problems. The purpose of this paper is to design an effective control method for liquid crystal glass kiln. The system has the advantages of small overshoot, good stability, short adjusting time and small steady-state error, which can effectively resist coupling interference. In the selection of heating mode of kiln, this paper chooses the mixed heating mode of gas combustion heating and electric melting heating, and expounds the temperature control loop of the two heating modes. In the research of temperature control method, the traditional pid control method is combined with fuzzy control method, and feedforward control is added to design a fuzzy pid control algorithm with feedforward. This control algorithm not only has the characteristics of small steady-state error of pid control, but also has the characteristic of small overshoot of fuzzy control. Adding feedforward shortens the adjusting time of interference and reduces the steady-state error. The main contents of this paper are as follows: (1) the influence of heating mode and temperature control on the quality of liquid crystal glass kiln is analyzed. In this paper, the production process of liquid crystal glass and the core position of temperature control in liquid crystal glass kiln are analyzed. The structure of feedforward and feedback controller is determined, and the temperature control block diagram with feedforward is given. (4) the fuzzy pid control algorithm is studied. Combining pid control with fuzzy control, a fuzzy pid control algorithm is designed, and the realization of fuzzy pid control on PLC is completed. The effect of fuzzy pid control and fuzzy pid control with feedforward on temperature control of liquid crystal glass kiln is analyzed. The results show that the fuzzy pid control method with feedforward has small overshoot and high steady-state precision. The comprehensive advantage of strong anti-interference ability.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ171.623;TP273

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