Second-order sliding mode control based on finite-time disturbance observer for alum dosing system of water plant
WANG Dong-sheng
ZHANG Peng
SUN Jin-hao
GUO Ruo-han
JIANG Guo-ping
Abstract：The flocculation and sedimentation process of water plant has the characteristics of strong nonlinearity,uncertainty and time-varying parameters,and disturbances of sudden changes in raw water quality and water flow are easy to adversely affect the flocculation and sedimentation process.This paper proposes a control design method of second-order sliding mode based on the finite-time disturbance observer for alum dosing system.First,the feedback control of alum dosing system is designed by second-order sliding mode control method with non-smooth terms.Then,a finite-time disturbance observer is designed to estimate disturbances of sudden changes in raw water quality and water flow,as well as model mismatch caused by strong nonlinearity,uncertainty,and time-varying parameters in the flocculation and sedimentation process.The estimation result is combined with feedback control as feedforward compensation.Finally,the theoretical analysis proves the stability of second-order sliding mode control method based on the finite-time disturbance observer.The simulation results show that the composite control method proposed in this paper effectively improves the robustness and anti-disturbance performance of alum dosing system.
Keywords：alum dosing controlfinite-time disturbance observersecond-order sliding mode controlanti-disturbance
Publication Date：2023-11-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 1965-1971 )