基于灰色预测的可拓控制方法

Grey-Prediction-Based Extension Control Strategy

由于控制系统所固有的滞后性,可拓控制也和其他"事后"控制方法一样,无法实现精准的控制效果。为了克服一般可拓控制的缺点,提出了一种基于灰色预测的可拓控制方法。该方法先对系统输出量进行灰色预测,然后将预测结果与给定值比较,二者差值作为可拓控制器的输入量,再经特征量提取、关联度计算、测度模式识别和控制决策等环节,得到控制量作用于控制对象。这种方法结合了灰色预测技术"事前"控制和可拓控制策略不要求建立精确的数学模型,实时性好的优点,可以使控制系统获得优良的动态性能。以一个典型滞后系统为对象进行了仿真。结果表明,基于灰色预测的可拓控制方式可以获得较PID控制和单纯的可拓控制更好的控制效果。

Like other ＂afterward＂ control methods,the accuracy of extension control is also poor because of the inherent hysteresis quality of control system.A new extension control method based on grey prediction is proposed to overcome the shortcomings of generic extension control.After system output variable is grey-predicted,the error between prediction value and setting value is taken as the input of extension controller.The output is obtained by character-variable picking,relationship-degree computing,measurement-mode identifying and control-strategy making.Dynamic performance of control system can be enhanced by use of the method because it combined strongpoints of grey prediction and extension control.The simulation study is performed on a time-lag system,and the results indicate that the grey-prediction-based extension controller has better control effects compared with PID controller and simple extension controller.