Application Of Robust Control Method In Teh Wastewater Treatment

Water pollution is the top issue facing the world, through the sewage treatment to solve the problem of water shortage has become a consensus.The pollution control subjects have been listed on the World Environmental Protection Organization's work schedules.Activated sludge is an economical and simple sewage water treatment technology in wastewater treatment system in both at home and abroad.It can be used to improve the quality of water.Dissolved oxygen volume in wastewater biochemical reaction process is one of the important indicator, which can reflect the entire system of operation condition intuitively and quickly, the accurate control of aeration pool of oxygen (DO) can directly affect the sewage process and system energy consumption.It is the premise to obtain good effect and economic benefit.Based on the paper"optimal robust control in variable parameter of activated sludge system", Y.Z.Feng and T.R.Long present a mathematical model of the SBR.Analysis and Research the model of SBR, change the model simplify the conditions to establish a new model.Due to the stability, controllability analysis of the newly established model, verification of the new model has the inherent instability.Based on Lyapunov stability theory and linear matrix inequality theory, constructing a Lyapunov function, solving the LMI that can meet the conditions, design controller to make the closed-loop feedback control system is stable.In actual treatment process, in connection with the wastewater influent flow uncertainty, the uncertainty of real physical modeling process because of simplification and linear approximation, the uncertainty of kinetic parameters caused by temperature changes, according to the model parameter uncertainty design robust controller;For the hardware, such as A/D, D/A converter errror, software such as calculation of truncation error, and other reasons, resulting the controller parameters uncertainty, the control system instability, non-fragile controller is designed to ensure system stability, to meet the control performance requirements;Due to on-line detector of microbial concentration is high, constructing observer, designed observer-based robust non-fragile controller.Last MATLAB simulation shows the correctness and effectiveness of the method.Designed a set of sewage treatment aeration control system.Control system in the forms of IPC+PLC, use of siemens S7-300PLC as data acquisition and software Kingview as monitors to complete the automatic control system design.Through the dynamic data (DDE) to complete data communications between King and MATLAB, achieve system control with complex control algorithms.Use of experimental devices to compare the non-fragile PID control and robust control methods.Computer simulation studies and experiments show that using the proposed non-fragile robust control in activated sludge wastewater treatment process control is effective.