Nonlinear joint state and parameter estimation: Application to a wastewater treatment plant

• Published in: Control engineering practice Vol. 21; no. 10; pp. 1377 - 1385
• Main Authors: Bezzaoucha, S., Marx, B., Maquin, D., Ragot, J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2013; Elsevier
• Subjects: Automatic; Engineering Sciences; Joint state and parameter observer; Takagi–Sugeno model; Time-varying nonlinear system; Waste water treatment plant; Takagi–Sugeno model; Waste water treatment plant; Joint state and parameter observer; Time-varying nonlinear system; Takagi-Sugeno model; joint state and parameter observer; waste water treatment plant
• ISSN: 0967-0661; 1873-6939
• DOI: 10.1016/j.conengprac.2013.06.009

A systematic approach to joint state and time-varying parameter estimation for nonlinear systems is proposed in this paper. Applying the sector nonlinearity transformation to both the system nonlinearities and the time-varying parameters, the original system is equivalently rewritten as a Takagi–Sugeno system with unmeasurable premise variables. A joint state and parameter observer whose parameters are designed by solving an LMI optimization problem is then proposed. The target application is a realistic model of an activated sludge wastewater treatment plant, being an uncertain nonlinear system affected by a time-varying parameter. •Joint state and parameter estimation for nonlinear time-varying systems.•A systematic procedure of representation with no loss of information.•First contribution based on the polytopic approach.•Application to a wastewater treatment plant.•Data issued from the European Program Benchmark Cost 624.