基于切换控制的均匀液位控制

Averaging level control based on switching control

过程工业中常常提出均匀液位控制问题,即在保证液位不出界的前提下,使输出流量尽可能平缓。对于此类受限控制问题,模型预测控制可以取得满意效果,但在线优化的复杂性又阻碍了算法在实际中的推广。基于模型预测控制,提出了一种通过调整预测时间域长度来处理液位约束的方法,加上对未知扰动的估计算法,最终推出切换PI控制律。该方法既简化了在线优化过程,又增强了对随机扰动的适应性,已成功地应用于甘肃金川集团公司6kt磨浮系统中。

The process industry often uses averaging level control, which seeks to make the outlet flow as smooth as possible while keeping the tank level within the upper and lower limits. Model predictive control can solve such problems, but the complexity of the online optimization makes it difficult to implement. A new model predictive control approach was developed which changed the length of the receding horizon. Further a switching PI controller was derived based on estimates of the unknown disturbance flow. This approach simplifies the complexity of the nonlinear constrained optimization problem and enhances the adaptation to random flow disturbances. The controller has been successfully applied to a grinding and flotation system in an industrial setting.