【作者】 安雅雅；

【导师】 孔祥东； 高英杰；

【作者基本信息】 燕山大学 ， 机械电子工程， 2006， 硕士

【摘要】 可逆式冷轧机是现代机、电、液一体化系统的典型代表,建立其液压压下系统的精确数学模型是进行系统分析、设计和最优控制的前提。本文结合燕山大学300mm试验轧机设备,针对轧机HAGC系统,采用机理建模和系统辨识技术相结合的办法建立其机、电、液一体化的轧制模型。本文综合考虑了轧机辊系变形、压下缸初始行程、辊系偏心、轧件的塑性变形和来料厚度对板厚精度的影响,并考虑了液压控制系统各组成部件的动态特性,依据滑阀的流量方程、液压缸流量连续性方程、液压缸和负载的力平衡方程,建立了对应轧机各设备部件且便于分析各部件性能的机电液一体化模型。在现场模型参数的确定方面,由于液压系统本身存在某些难以确定的参量,采用控制领域的系统辨识技术确定这些特征参数。首先对普通最小二乘法、加权最小二乘法、增广最小二乘法和辅助变量法进行阐述、比较和分析,并理论上分析电液伺服控制系统辨识的计算机实现问题。其次对300mm轧机电液位置伺服系统进行了辨识实验研究,实验中用计算机产生相应的系统辨识输入信号,基于RLS算法和ARX模型方法的两种辨识程序对系统进行参数辨识。通过对辨识结果评价指标进行对比,发现ARX模型方法有较高的辨识精度,并对这种辨识方法进行验证。进一步利用ARX模型方法辨识确定了液压系统的数学模型。更多还原

【Abstract】 The reversible cold rolling mill is the typical model of modernelectro-hydraulic and mechanical systems. Research on its precise mathematicmodel is the precondition of system analyzing, designing and optimizingcontrol. Based on the HAGC system of the 300mm experimental rolling mill ofYanshan University, cooperated with system identification and modeling bymechanism, this paper constructs the complete model for the rolling mill.Considering such factors as deformation and eccentricity of roller, theinitial range of hydraulic cylinder, the plastic deformation of the strip and inputgauge, as well as their effects on the thickness accuracy, dynamic performancesof hydraulic control systems, according to the flow equation of slide valve, theflow continuity equation of hydraulic cylinder, the force balanced equation ofhydraulic cylinder with load, the electro-mechanical model is established.As it’s difficult to determine some hydraulic system parameters, systemidentification is implemented to identify some parameters of HAGC system.First it gives analysis and comparison to Least Squares, Weighted LeastSquares, Extended Least Squares and Instrumental variables, then analysestheoretically the problems of how to realize the identification in computer.Secondly, it does experiments on the identification of electro-hydraulic positionservo system. The input signal is creased in computer. Compares theidentification results of RLS with ARX, found that the latter one have the betterprecision, then test the ARX model identification. Establishes the mathematicalmodel of the hydraulic system in the later method.更多还原