【作者】 方华；

【导师】 张德文；

【作者基本信息】 重庆大学 ， 机械电子工程， 2003， 硕士

【摘要】 板厚和板形精度是板带材的两大质量指标，随着轧制理论、控制理论的发展，以及它们在轧制过程中的应用，使得板带产品的厚度精度与板形指标有了很大的提高。板厚自动控制是板带轧制领域的两大关键技术之一，它直接关系到产品的质量和经济效益。双辊连铸薄带钢技术作为钢铁生产中短流程、低能耗的一项新技术，代表了今后钢铁工业的发展方向，因此，对其厚控系统进行理论分析和应用研究具有重要的现实意义。本文在总结概括厚度自动控制技术基本现状和发展趋势的基础上，以实际技术应用为导向，对轧机厚度自动控制的基本原理进行了细致的研究，讨论了厚度自动控制的工艺基础理论，包括轧机的弹性方程、轧件的塑性方程、弹塑曲线图（P－H图）和厚差方程等。在此基础上讨论了AGC的基本方式：厚度AGC、压力AGC、前馈AGC、张力AGC、秒流量AGC，分析讨论了它们的特点及其各自适用范围，指出应根据轧机型式、产品精度要求，选择其中几种控制方式，构成轧机综合厚度自动控制系统。进一步研究了常用的几种压力AGC的控制模型：BISRA模型、解耦设定模型、厚度计模型、动态设定模型以及PID厚度计模型。通过对这些模型的分析，得到了它们各自的特点和动态响应特性，为选用AGC控制方式提供了理论基础。根据以上的研究分析，结合设计要求和实际情况，把厚度自动控制理论应用于连铸机上，设计了双辊连铸机的液压AGC系统，包括液压系统和控制系统。液压系统采用阀控缸形式的电液位置伺服系统，用以准确、快速的控制压下位移，达到控制空载辊缝大小的目的，它是整个厚度自动控制系统的基础。控制系统采用两级计算机控制结构，即过程计算机系统（上位机）和基础自动化系统（下位机），两级系统分别完成各自的功能。控制策略采用压力和监控AGC结合的控制方式，以保证板厚精度。最后，根据液压AGC系统的构成，采用面向对象的建模方法，运用经典建模理论，建立了电液伺服控制系统的数学模型和方框图，并对其进行了动态特性分析。更多还原

【Abstract】 The thickness accuracy and shape accuracy of steel strip are two key quality performances of steel strip. They are greatly improved due to the progress and application of roll theory and control theory. Automatic Gauge Control (AGC) is one of the two key technologies in the rolling field and directly affects the quality of strip products. Twin-roll steel strip casting is a new steel-strip production method of representing the steel industry tendency. Thus, research on AGC system has important theoretical and practical significance.The basic theory about AGC used in rolling mill is scrupulously studied in the paper, based on an overview of the present status and perspectives of AGC technologies. The paper also discusses the basic theory about rolling process, including elastic equation of rolling mill, plastic equation of rolled piece, elastic-plastic curve figure and gauge aviation equation etc. The modes of AGC are studied in detail, such as thickness AGC, pressure AGC, front feedback AGC, tensional AGC, monitor AGC, mass flow AGC. After analyzing features and fields of application, the paper point out that one or more modes should be used in the AGC system, considering the type of the rolling mill and accuracy requirements of products. Moreover, it analyzes the controlling modes of pressure AGC, which frequently used on rolling mill, including BISRA mode, decoupling set mode, gauge meter mode, dynamic set mode and PID gauge meter mode, gains the characteristics and dynamic behaviors of them, which provides fundamental basis for the design of AGC system.The hydraulic AGC system of the twin-roll caster has been designed, based on the studies and analyses mentioned above. It contains two parties: a hydraulic system and an electric control system. An electro-hydraulic position servo control system is used in the hydraulic system, which can press down the roller quickly and accurately to control the roll gap. The hydraulic system is the body of the wholly AGC system. According to the present status of the modern industry in and the characteristics of AGC system, the electric control system adopts two-level computer control structure: process automatic system and basic automatic system. The control strategy combines pressure AGC and monitor AGC. In the end, using the classical model building theory, the mathematic model has been established. Based on the model, the paper analyzes the dynamic behavior of the electro-hydraulic servo system.更多还原