Sewage BOD control method based on steady-state estimation of PID-RBF and soft measurement of LSSVM

The invention provides a sewage treatment biological oxygen demand (BOD) control method based on steady-state estimation of a PID-RBF and soft measurement of a least square support vector machine (LSSVM), and aims at solving the problem of hysteresis of BOD control in sewage treatment. The method comprises the steps of firstly, utilizing the LSSVM for conducting soft measurement on BOD, collectingvarious kinds of state data under control of PID, utilizing a radial basis function (RBF) network for learning to fit a relation between various states and steady-state output values of a PID controller under the states, then adopting a method of combining the trained RBF network for estimation of steady-state output with the PID controller for BOD control, and introducing integral control itemswhen an error is smaller than or equal to a certain predetermined value to improve the control precision. By means of the method, the defect of hysteresis of traditional PID sewage BOD control can beovercome, and stable BOD co