非线性Hammerstein模型预测控制策略及其在pH中和过程中的应用

所有实际工业过程都包含一定程度的非线性,如pH中和过程由于其本身的强非线性是工业过程控制中具有挑战性的难题,但至今为止仍缺乏有效的非线性控制方法。将基于差分方程模型的模型预测控制策略(model predictive control,MPC)推广到包含一个静态非线性多项式函数和一个线性差分方程动态环节的非线性Hammerstein系统,详细描述了基于静态非线性多项式函数的最优控制作用求解方法,提出了一套新的非线性Hammerstein MPC 控制策略(nonlinear Hammerstein predictive control,NLHPC)。pH中和过程控制仿真和控制实验表明,NLHPC的控制结果好于工业上常用的非线性 PID(nonlinear PID,NL-PID)控制器。

Nonlinear Hammerstein model predictive control strategy and its application to pH neutralization process

Industrial processes usually contain complex nonlinearities.For example,the control of pH neutralization processes is a challenging problem in the chemical process industry because of their inherent strong nonlinearity.In this paper,the model predictive control(MPC)strategy is extended to a nonlinear process using Hammerstein model that consists of a static nonlinear polynomial function followed in series by a linear difference equation dynamic element.The calculation strategy of optimal control output based on the static nonlinear polynomial function of the Hammerstein model is presented in detail.Thus a new nonlinear Hammerstein predictive control strategy(NLHPC)is developed.Simulation and control experiments of a pH neutralization process show that NLHPC gives better control performance than the commonly used industrial nonlinear PID(NL-PID)controller.