基于系统稳定性的高强薄板连轧过程振动失稳机理及控制策略研究

To fit with the goal of lightweight manufacturing, the high strength thin steel plate is becoming the leading product of the rolling industry. However, chatter has always been a baffling thing during rolling. Especially as the rolled product becomes more and more highly-strengthened and thin, the losing stability problem caused by chatter becomes more severe. Chatter in rolling is closely related to rolling process. But there is a lack of theories and models to describe the quantitative relationships between the rolling mill running state and the rolling process condition. Based on the structural characteristics and vibration characteristics of rolling mill equipment, considering the dynamic rolling process parameters, the project aims to establish a structure-process coupled mechanism analysis model. The model helps to study the vibration generation mechanism and evolution law from the viewpoint of system stability. And finally suppression measures are put forward based on the influence factors for the stability domain. On the one hand, the finish rolling speed, which insures the stable operation of tandem rolling mills, is considered as the objective function. The dynamic optimization model of the continuous rolling process parameters is established under the stable rolling constraint condition. On the other hand, active control of the parameter domain and the amplitude of vibration are conducted based on the Hopf bifurcation and nonlinear feedback control theory. The project is intended to establish a "rolling mill structure - rolling process" integrated modeling system, which provides theoretical support and technical guidance for the vibration mechanism and suppression solution of the typical cold and hot rolling system. The study establishes the foundation of the intelligent rolling industry.

钢结构轻量化可节材节能减排，促成板带钢产品减薄、高强度化的发展趋势。高强薄板轧机的自激振动问题再次成为困扰热、冷连轧生产的难题，使之以新的面貌出现并且普遍存在，呈现与产品及工艺的密切相关性，然而目前尚缺乏描述系统运行状况与工艺条件定量关系的模型和理论。本申请拟针对高强薄板轧机的结构和振动特征，考虑轧制过程工艺参数的动态变化，建立“结构-工艺”相耦合的振动机理分析与行为模拟模型，从系统稳定性角度揭示振动的产生机理、失稳条件和演化规律，根据稳定参数域提出解决对策。一方面考虑稳定轧制约束条件建立连轧工艺参数动态优化模型，以终轧速度为目标函数实现系统的高速稳定运行；另一方面基于Hopf分岔及非线性反馈控制理论实现对参数域和振动幅值的主动控制。以期架构基于系统稳定性的“结构-工艺”一体化建模体系，为冷、热连轧机振动的产生机制和解决办法提供理论支撑和技术指导，并为实现高强薄板连轧工业的智能化奠定基础。

轧机振动问题始终是伴随轧制生产高速化、控制自动化和产品精细化进程的一个世界性难题，随着产品规格与强度的极端化发展，连轧过程振动失稳变得更加突出。轧机实际速度远达不到设计值，一旦达到某临界值就会发生剧烈振动，且失稳阈值随着轧件规格和轧制工艺的差异也不同，导致难以预测与评估，其识别、诊断与采取措施完全依赖现场技术人员的经验，响应不及时或判断不准确都会对生产效率和产品质量带来严重影响，甚至威胁设备安全。.本项目立足非线性动力学与系统稳定性基础理论，聚焦高强薄板轧制过程的复杂动力学问题，面向钢铁工业智能化重大需求，拓展学科方向和内涵，围绕两个方面开展相关的研究内容：.（1）复杂流程装备的多物理场耦合动力学行为与振动失稳。提出了系统稳定性理论与流程工业装备相结合的新思路和方法，以冷轧机组为对象架构了“结构-工艺-控制”相耦合的动力学机理建模框架，提出了“临界轧制速度”的概念和基于前滑值的颤振评价指标；.（2）机理与数据协同驱动的振动失稳智能预报与工艺优化决策。基于动力学演化机理和工业大数据统计规律，建立了冷连轧机组的时空融合颤振预报模型，实现颤振的智能预测以及面向抑振提速综合目标的工艺规程动态优化。.本项目的核心学术成果发表于MSSP和机械工程学报等学术期刊，并实现学术成果的产业化落地应用，自主开发的“工艺参数智能优化计算系统”应用于C202冷连轧机组，典型薄料由1300m/min提速到1700m/min稳定轧制，实现了显著抑振提速，相关成果获2018年冶金科学技术一等奖。本项目的研究对于突破高强薄板轧制生产中的“颤振”瓶颈问题，以期实现高速稳定运行具有重要的工程价值和科学意义，对于整体提升连轧过程生产核心工艺的智能化水平和实现智能制造目标也具有积极的推动作用。