设限频域前馈板厚控制策略的研究

Study on Finite Frequency Domain Feedforward Gauge Control Strategy

近年来随着板厚控制技术的发展,冷轧板带产品厚度精度有了显著提高,但现代化工业生产对板带产品厚度精度也提出了更高的要求,高精度冷轧板带仍需大量进口,所以深入研究如何进一步提高冷轧板带产品厚度精度具有重要意义。目前冷带轧机上应用的厚控系统主要是反馈式控制方式,这种控制方式虽然具有稳定可靠的特性,但有控制时滞的缺点,严重影响控制精度的进一步提高,而前馈控制策略虽然在理论上可以弥补反馈控制时滞的缺点,但实际应用情况表明,传统前馈存在着诸多局限性,针对传统前馈控制的重叠和抗噪问题,综合提出设限频域前馈板厚控制策略,并结合"频域"涵义扩展的思想,给出了前馈控制设限频域范围的确定和实现方法,并进行了对比实验,实验结果证明了该控制策略的优越性。

With the development of gauge control technology in recent years,thickness accuracy of cold-rolled strip products has been significantly improved,but the modern industrial production also put forward higher requirements on the thickness accuracy of strip products,large quantities of high accuracy cold-rolled strip are still needed to import,so further study on improving the thickness accuracy of cold-rolled strip products is important in significance. At present,the cold rolling mill gauge control is mainly feedback control,this control method has the characteristics of stability and reliability,but it has the disadvantage of the control time delay which seriously affects the control accuracy improving further. Moreover the feedforward control strategy,in theory,can compensate for the disadvantage of feedback control time delay,but the practical application of traditional feedforward showed that there were many limitations. The finite frequency domain feedforward gauge control strategy is proposed comprehensively against the problem of overlapping and noise immunity in traditional feedforward control. In combining with the extension of the meaning of 'frequency domain',the method how to determine and achieve the finite frequency domain of feedforward control was given,and the comparative experiment was carried out. The experimental results verify the superiority of the proposed control strategy.