【作者】 刘建；

【导师】 王益群； 李连平；

【作者基本信息】 燕山大学 ， 机械电子工程， 2008， 博士

【摘要】 板形是板带产品的主要质量指标之一,随着板厚品质的不断提高,人们对带材板形质量提出了越来越高的要求。板形控制成为现代高精度板带轧机关键技术的重要发展方向之一。板形检测、板形识别与板形控制理论及数学建模则是此项技术的理论基础和关键问题,同时也是板形控制的难点。目前,只有国外的大公司如西门子、ABB等研发出了应用于实际板形控制的板形闭环控制系统。国内板形检测和板形控制系统基本处于研发阶段。本文在燕山大学王益群教授课题组研发的七段式气动板形检测辊的基础上,对气动板形检测辊重新进行了动态特性标定,采用光纤传感技术对检测辊鉴相定位的方法较好的消除了检测辊圆周误差,进一步完善了气动板形检测装置。运用虚拟仪器LabVIEW技术开发了气动板形检测系统,实现了对板形信号的在线实时检测;针对现代板带轧制的特点,在模糊分类原理模式识别基础上,结合粒子群理论和单纯形优化算法对模式识别的结果作了进一步优化,使其更好的反映了实际板形状况。通过计算机网络通讯技术,将板形模式识别结果传输到300四辊可逆轧机的板厚控制系统中,通过控制四辊可逆轧机弯辊和倾辊装置完成板形的闭环控制。由于弯辊系统是板形闭环控制的关键环节之一,它的动态特性和稳态性能对于整个板形控制系统的性能起着至关重要的作用。针对其非线性、时变性及不确定性的特点,为充分发挥液压弯辊力对板形的调整作用,改善轧机系统的动态特性,设计了模糊自适应PID控制器应用于液压弯辊控制中。随着计算机技术的迅猛发展,虚拟仿真技术越来越成为系统设计、模拟的重要组成部分。虚拟轧制技术的出现对了解系统性能、改进控制技术以及研究工艺过程具有重要的理论意义和实际应用价值。可以为现代化轧机的设计和现有轧机的改造提供技术支撑和仿真试验环境;可以探索现有轧机工艺特性,改善工艺参数,以提高产品的质量与产量。本课题在考虑伺服阀的非线性,综合考虑了液压系统中油缸位移、轧制力、弯辊力等因素对板形的影响,建立了液压压下、弯辊系统模型;根据完整的板形理论分别建立了轧件金属三维变形数学模型、辊系弹性变形数学模型、轧制力数学模型。为提高虚拟轧制板形控制的仿真速度,对金属三维变形模型进行了一些简化;辊系变形采用轧制工程上应用较广的影响函数法;在以上模型基础上,建立了较完备的虚拟板形控制系统。更多还原

【Abstract】 Strip flatness is the main quality standard. Following the improving of the quality of strip thickness, the request to the one of strip flatness is higher and higher. Flatness control becomes the important technique’s developing direction of the modern high-precision rolling mill. Flatness measuring, pattern identification, flatness control theory and mathematical modeling are the theory base and the key problem of the flatness control. Currently, only foreign companies, such as Siemense and ABB, can explore the flatness closed-loop control systems, which are applied in the practical flatness control. Domestic flatness control and measuring lies in the research phase. The dynamic characteristic of the pneumatic flatness measuring rolls is calibrated again on the base of the seven-segment pneumatic flatness measuring roll explored by the research group led by Professor Wang Yiqun. It adopted the method of optical fiber phase Correction Compensation to eliminate the circle error of the measuring rolls and perfecting pneumatic flatness measuring equipment. On this base, Virtual Instrument LabVIEW is used to explore the software system of pneumatic flatness measuring, which realizes the on-line measuring. Aimed at the characteristics of modern rolling, on the base of the pattern recognition based on fuzzy classification theory, the result of the pattern identification is optimized, combining with the Particle Swarm theory and simplex method, which reflects the real flatness state better. By the computer Ethernet communication technique, the result of the flatness pattern identification can be transmitted to the automatic gauge control system of the 300 4-roll reverse rolling mill which can realize the flatness closed-loop control by the bending equipment and the incline roll equipment. As the bending system is the key technique of the flatness closed-loop control, its dynamic and static characteristics are important for the performance of the flatness closed-loop control system. Aimed at its characteristics of nonlinear, time-variant and uncertainty, Fuzzy Self-adaptive PID is designed in bending system for improving the adjusting role of hydraulic bending system on flatness and dynamic characteristic of the rolling mill.With the development of the computer technique, the technique of the virtual simulation increasingly becomes the important constituent of the system design and simulation. Virtual rolling technique has important practical values for learning the performance of the system, improving the control technique and studying the technics process. It can provide the technique support and the simulation experiment environment for the design of modern rolling mill and rolling mill modification, and it also can explore the new characteristics of the current rolling mill and improve technics parameters to improve the quality and the output of the product. Considering the influence such as nonlinearity of servo valve, the hydraulic cylinder position, rolling power and bending power on the flatness, this subject builds the model of hydraulic screw-down system and the bending system. According to the whole flatness theory, strip metal transmutation model, rollers elasticity transmutation model and rolling power model are built respectively. To improve the simulation velocity, strip 3-dimension metal transmutation model is simplified. The influence function method is applied on rollers elasticity transmutation model, which is used widely in the practice. On the base of the model above, a whole virtual flatness control system is built更多还原