Batch-to-Batch Optimal Control Of Batch Process Based On Piecewise Linear Model

In order to adapt to market competition,batch process,as an ancient productive process,has received renewed attention.The batch process is widely used,but the automation level of it is low.Piecewise linear model is a kind of nonlinear black-box model which is linear in different sub-domains of the definition domain.In this paper,PWL model is applied in batch process modeling.On the basis of previous studies,batch-to-batch optimal control strategy based on PWL model is proposed.According to the nature of batch process,the strategy and PWL modeling method are improved.A batch-to-batch optimal control strategy based on the model of adaptive hinging hyperplanes(AHH)is proposed for the products quality control of batch process.As a piecewise linear model,AHH model is used for black box modeling for batch processes.The paper introduces the batch-to-batch optimal control strategy based on the idea of iterative learning control.The AHH model is applied in the strategy and the convergence of the process after implementing the proposed strategy is analyzed.The effectiveness of the strategy is verified by simulation in a typical batch reactor.To solve the problem of product quality control in multi-variable batch process,an batch-to-batch optimal control strategy based on MIMO-AHH models is proposed.The existing AHH model is extended and the training algorithm of MIMO-AHH model is obtained.It is proved that MIMO-AHH model has uniform approximation ability.Based on the idea of feedback correction in MPC,feedback correction is used on the batch axis to correct the MIMO-AHH prediction.The simulation is carried out on the styrene polymerization reactor and the performance of the strategy is shown.In order to make full use of the measurement data of batch process and reduce the influence of measurement noise,a batch-to-batch optimization control strategy based on the model structure of NARX and EKF correction is proposed.The MIMO-AHH is used to establish the non-linear mapping in the model structure of NARX,and then theblack box model of batch process is obtained.According to the repeatability of batch process,EKF is introduced into batch axis to realize batch-to-batch optimal control based on EKF correction.