Identification and optimization for hydraulic roll gap control in strip rolling mill

In order to improve the control performance of strip rolling mill, theoretical model of the hydraulic gap control(HGC) system was established. HGC system offline identification scheme was designed for a tandem cold strip mill, the system model parameters were identified by ARX model, and the identified model was verified. Taking the offline identified parameters as the initial values, online identification using recursive least square was carried out with model parameters changing. For the purpose of improving system robustness and decreasing the sensitivity due to model errors, the HGC system based on generalized predictive control(GPC) was designed, and simulation experiments for traditional controller and GPC controller were conducted. The results show that both controllers acquire good control effect with model matching. When the model mismatches, for the traditional controller, the overshot will increase to 76.7% and the rising time will increase to 165.7 ms, which cannot be accepted by HGC system; for the GPC controller, the overshot is less than 8.5%, and the rising time is less than 26 ms in any case.

热镀锌连退过程C翘机理及其预报模型

为有效降低带钢C翘发生风险,提高其表面镀层均匀性,研究了热镀锌连退过程C翘形成机理。充分考虑到热镀锌连退过程的设备与工艺特点,从弹塑性力学角度详细分析带钢C翘形成机理,并推导出C翘机理力学模型。采用条元法建立带钢C翘预报计算模型,并基于此采用优化递推法成功解决生产应用C翘预报模型难点。最后,在此基础上编制热镀锌机组连退过程带钢C翘预报软件应用于现场,并分别预报两种典型规格带钢在炉内不同工艺段板形翘曲演变过程。结果表明,机组出口板形预报值与其实测值的偏差满足产品精度要求,该模型能实时预测炉内工艺段板形,为后续工艺参数优化提供理论指导,具有进一步推广应用的价值。