The Application Of Adaptive Control Based On Fuzzy Neural Network In Neutralization Process Control

Neutralization process is a typical nonlinear process with pure time delay. This process can't be controlled effectively with conventional linear control method. Feed back control base on Nonlinear PID with self-adjust parameter and feed forward control base on experience model are employed in the practical application. The realization of this control system and its result are introduced in this paper. Because the process of the reaction is complicated, it's difficult to model for it. The Nonlinear PID can't fit the change of the reaction. The feed forward control base on model also can't fit the change of pH value and flux of the original water. So the control method can't get a good result.In terms of the above considerations, this thesis proposes a new nonlinear adaptive control method based on fuzzy neural network to realize optimization control of pH neutralization process. Fuzzy neural network not only has the characteristic of fuzzy system, but also has the characteristic of neural network. The nonlinear adaptive control method based on fuzzy neural network can learn and adjust rule parameter and subjection parameter on line. And the control rule list is calculated according to control data on the spot, which is also applied to the control on the spot. Therefore, it has good adaptive and robust and also can ensure the stability of closed loop control system, which is fit to handle both the nonlinearities and time-varying characteristics of the pH process.The research work of this thesis consists of the following major parts:Firstly, this thesis summarizes the development of intelligent control and also introduces the advantage and disadvantage of fuzzy control technique and neural control technique respectively. The characteristic and application of adaptive control are also presented in this thesis.Secondly, the traditional control for pH process ?the compensation of nonlinearities plus PID control is presented in this thesis.Thirdly, the fuzzy neural network controller is designed and the adaptive control method based on fuzzy neural network is proposed according to the advantage and disadvantage of fuzzy system and neural network in this thesis. And the adaptive control method based on fuzzy neural network is applied to pH process.Forth, Aimed at the process of pH value control of wastewater treatment in chemical factory, a PLC-based automatic control system of pH value of wastewater treatment is developed. In this thesis operation principle of this system, hardware configuration, and software configuration are all discussed in detail.At last, a summary of the paper is given and further research interests are also proposed.