基于流量预估的直拉式冷轧机液压张力控制策略

Hydraulic tension control strategy based on flow prediction for hydraulic-tension experimental cold mill

根据带钢性能和工艺开发的要求,开发了机架前后配置张力液压缸的直拉式冷轧实验机.通过设置张力控制器直接对实际张力进行闭环控制的方式,无法实现张力液压缸速度与轧制速度的匹配,也无法满足动态下高精度且稳定的张力控制要求.针对此问题,通过对张力液压缸流量方程的研究,提出了基于流量预估的液压张力控制策略.流量预估控制精确计算出同时满足张力液压缸移动速度和设定张力的伺服阀控制电流,同时对控制因子进行在线修正以获得最优预估控制效果.动态张力补偿控制补偿预估控制后剩余的张力偏差.现场应用效果表明,该策略取得了良好的控制效果,动态下张力控制误差小于±3%.

According to the requirement of strip properties and technology development,a hydraulic-tension experimental cold mill with tensional hydraulic cylinder was developed.Through the tension controller to control the actual tension,a good match between tensional hydraulic cylinder speed and rolling speed can not be obtained,and the requirement of high-precision and stable tension control can not be satisfied.Aimed at these problems,on the basis of research on the flow equation of tensional hydraulic cylinder,a hydraulic tension control strategy based on flow prediction was proposed.A control current of servo valve to satisfy the need of not only speed of tensional hydraulic cylinder but also the tension reference was calculated accurately.The control factors were on-line corrected in order to obtain optimal predictive control effect.The residual tension deviation after predictive control was compensated by dynamic tension compensating control.The practical application results showed the well control effect was achieved by present strategy,and the dynamically tension control error was less than ± 3%.