稀释水流浆箱的横向定量控制及其算法探究

Research on Cross-Directional Control of Dilution Water Headbox and Its Algorithm

随着人们日常生活和相关工业对纸张质量需求的提高,带有横向定量控制系统的稀释水流浆箱应运而生;由于横向定量控制系统具有大量的横幅定量输入信号和大量的电动阀门执行器,且存在大时滞、多约束问题,曾取得良好控制效果的模型预测控制(MPC)算法因其在线计算量过大而难以直接应用;先以一种改进的椭球算法代替传统的在线求解二次规划问题再将所有"将来"的控制动作视为无约束控制输出,这种算法大大减小了MPC算法在线计算量;仿真实验表明,这一算法能在几乎不降低控制效果的前提下缩短横向定量控制问题的在线计算时间。

With the needs of daily lives and related industries to improve the quality of the paper, the dilution water headbox with cross-directional control system came into being. Because of quantitative input signal and the large number of electric valve actuators of cross- directional control system, and the presence of large time delay as well as constraints, the model predictive control （MPC） algorithm, which had achieved satisfactory control effect, now tends to be hardly used directly for its large online computational requirement. The method of replacing solving quadratic program online with a modified ellipsoidal algorithm and then treating all future actuator settings as unconstrained to reduce online computation of MPC algorithm significantly. Simulation results show that this algorithm indeed reduced the online computa-tion time of cross directional control problem with minimal loss in performance.