Study on random distribution control method of pH value in biological oxidation pretreatment process
pH value of oxidation tank is one of the key factors affecting activity of bacteria in pretreatment process of biological oxidation.However,the pH value output morphology distribution does not conform to the Gaussian distribution,which makes the traditional mean and variance difficult to describe the output pH value distribution.A control method of probability density function(PDF)statistics information for pH output of pulp is proposed.Firstly,B-spline is used to approximate PDF statisties information of pulp output pH value.Secondly,aiming at the relationship between weight vectors,dynamic neural networks(DNN)is used to establish nonlinear dynamic model between control input and weight vector.Based on the PDF statisties information weight model of pH,the variable structure controller of sliding membrane is designed.Stability analysis is carried out by constructing Lyapunov function.Finally,tracking of output PDF statisties information on target PDF statisties information is realized.Simulation results demonstrate the effectiveness of the proposed method,which provides a new method for biological oxidation pretreatment process.
oxidation pretreatment processpH random distributionB-spline modelprobability density function (PDF)statistics informationdynamic neural network(DNN)sliding mode control