The Expert Intelligent pH Controller and Its Application

Pang Quan¡¡¡¡Yang Cuirong

(Hangzhou Institute of Electronics Engineering¡¡Hangzhou¡¡310012)

¡¡¡¡ABSTRACT£ºIn consideration of the high non-linearity and time-delay characteristics of the pH process,an intelligent pH controller is developed in this paper on the basis of the expert system theory.The main characteristics of the controller is that it can self-organize the different control strategy according to the different working condition of the pH process so as to yield the best process result.The controller mainly consists of a inference machinery and a knowledge library which contains several sub-knowledge libraries such as chemical library,system information library,control model library, control parameter library,trouble treatment library and so on.The working principle of the controller is presented and a block diagram of the controller¬ðs structure is also given in the paper.As an example of application,the paper shows at last how a nicotine dissociation process,which requires rather precise control with non-overshot of temperature and pH value under serious non-linearity and time-delay characteristics,is well controlled by the controller presented in this paper.