关于轧机生产板材轧辊偏心控制优化研究

Roller Eccentric Signal Control Based on Single Sub-Band and Ratio Correction Method

在板材的生产过程中,由于轧辊偏心扰动影响板材厚度的精度,而传统FFT算法在轧辊偏心控制中存在识别误差。针对上述问题,提出了一种基于单子带重构改进算法和比值校正法相结合的偏心信号重构新方法。首先采用单子带重构改进算法对偏心信号进行分频,并且有效的去除噪声,在信噪比低和频率相近时能够准确的提取偏心信号的频率及谐波个数,弥补了比值校正法对噪声敏感的弱点及对各谐波分量间隔大的要求。然后使用比值校正法对各次谐波幅值和相位进一步估计。仿真及实验结果表明,利用结合方法重构得到的轧辊偏心模型可以很大程度减小厚度波动,使轧辊偏心控制精度达到了补偿要求。

Roll eccentricity is the main factors to influence the sheet thickness precision in the production process in sheet, and Fast Fourier Transform（FFT） method has some shortcomings at the roller eccentric signal extraction. Therefore a new roll eccentricity signal reconstruction method is presented, which combines improved single sub-band reconstruction algorithm and ratio correction method. Firstly, the eccentricity signal is decomposed in different frequency band and effectively eliminate noise by using improved single sub-band reconstruction algorithm; in low SNR and with similar frequencies, this method still has high spectral resolution and can accurately extract the frequencies of the eccentric harmonies and the number of the harmonics. This method remedies the weaknesses of sensitive to noise and the demand for the big interval of each harmonics. Then, ratio correction method is used to estimate the am- plitudes and phases of the harmonies. The simulation and experiment results show that the reconstructed eccentric model with the method can greatly reduce the thickness fluctuation.