模糊逻辑扩展DMC算法及仿真

提出一种模糊逻辑扩展动态矩阵算法,该算法的主要思想是在不同工作点作阶跃响应,建立局部线性模型,然后利用隶属函数对局部线性模型进行加权。并将约束输入思想引入到DMC算法中来,避免求逆矩阵。实现起来占用内存小,计算速度快。算法对于系统开环y-u曲线单调递增或递减的情况,只要做3个工作点的阶跃响应即可建立起系统模型;即使开环y-u曲线不单调,也可以对系统进行分段处理建立模型。算法的应用范围较广。对非线性连续发酵过程的仿真研究表明该算法控制效果较好,具有很好的理论和实践价值。

Fuzzy-logic Extended DMC Algorithm and Simulation

A fuzzy-logic extended DMC algorithm is presented in this paper.The main idea of the algorithm is to set up local linear models on the different operating point of nonlinear systems,and then use membership function to introduce weighted coefficient for the local linear models.The input constraints to DMC are introduced,in which the inverse matrix does not require calculating.The computational speed of the algorithm is higher.The open-loop y-u curve of the nonlinear systems is monotone increasing(or monotone decreasing),which guarantee the local linear model could be set up with the obtained step responses on three operating points.Even if the open-loop y-u curve is not monotony,the system can be piecewise linearized.So there is a large application range for the algorithm.The simulation results of the nonlinear continuous fermentation control system shows that the proposed control system has good performance.