Grey-Prediction-Based Extension Control Strategy

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.