The Sliding Mode Control Study On Dissolved Oxygen Concentration Of Sewage Treatment Process

Based on the problem of urban sewage, the sliding mode control of dissolved oxygenconcentration is carried out in the activated sludge process. According to the ActivatedSludge Model1(ASM1), the cell dynamics equation, aeration mechanism, materialbalance and the characteristics of actual sewage treatment system, the mathematical modelthat is suitable for control system is established and simplified.Based on the requirements of high reliability and security for the control systems andproduction processes, it studies the fault estimation of the delay systems for sewagetreatment process, and designs the adaptive observer, and proves consistent bounded of thestate and fault estimation error for the system by using Lyapunov stability theory, andverifies the feasibility and effectiveness by simulation with the LMI toolbox and Matlabsoftware. Because the dissolved oxygen concentration of aeration tanks is an importantindex of the entire sewage treatment process, it can quickly reflect the sewage treatmentsituation of the entire control system, and it’s quantity also affects the degree of removalabout organic compounds in water, the costs of operation and the quality of final effluentwater, so it is very important to design the rational controller for the control of dissolvedoxygen concentration. Due to the advantages of sliding mode control, which are the goodrobustness about outside interference and uncertainty parameter, the relatively simplecontrol algorithm and the easy online implementation, it achieves the control of dissolvedoxygen concentration by designing sliding mode controller, and proves the stability ofsliding mode controller by Lyapunov stability theory and linear matrix inequalities theory.and verifies the effectiveness of sliding mode controller by MATLAB simulation.It introduces the hardware structure and software design of the activated sludgeprocess dissolved oxygen concentration control system, the core is the implementation ofPID control algorithm and Sliding-mode control algorithm. Through DDE technology, itrealizes the data exchange between Matlab and Kingview, and verifies the effectiveness ofcontrol methods in activated sludge dissolved oxygen concentration control systemeventually.