The Research On Soft Sensor Modeling And Intelligence Controlling In Sewage Disposal Based On Biological Fluidized Bed

Biological fluidized bed(BFB) is a new technology of swage disposal with high efficiency. It belongs to a kind of complex system of nonlinear, strong delay, time-variation and multivariable coupling. It is difficult to build a precise mathematic model and lack of efficient method and scheme of control. The problems of the automatic control for BFB become the main obstacle for its commercial application.Characteristics and development of BFB are introduced in this paper, advanced control of swage disposal based on BFB and its'application are analyzed deeply. Then a method for intelligent control of swage disposal system based on BFB was put forward.To solve the problem that water quality of sewage disposal process (such as BOD5) is difficulty to measure on-line, meanwhile considering the characteristics of sewage disposal process which is related with time. A soft sensor method for water quality of swage disposal based on process neural network (PNN) was proposed. On the basis of learning algorithm based on orthogonal function basis expansion, genetic algorithm (GA) was used to optimize learning rate and realized learning rate adaptive adjustment. Experimental results show that the method is effective.In order to overcome the shortcomings of the nonlinear, time-delay, time-varying and multivariable coupling problems in sewage disposal system based on BFB, an improved T-S adaptive fuzzy control method based on GA is proposed. In the system, firstly using GA to optimize the membership functions, then reduce the dimension of fuzzy controller and simplify the rules by an integral unit. Moreover, adopt a prediction method to compensate the time-delay of system, which based on the theory of fuzzy. And the application of self-tuning PID control method that based on DRNN identification on BFB is modeled and researched by simulation。Experimental results show that the methods are feasible and effective.Finally, experimental control system for swage disposal based on siemens S7-200 is established. And monitoring software that is made by Webaccess and Flash interactive technology is introduced.