Process Nonlinearity

  • Cheng-Ching Yu
Part of the Advances in Industrial Control book series (AIC)


Despite the fact that most industrial processes are controlled using the linear PID controller, most chemical processes show a certain degree of nonlinear behavior. Therefore, it is important to provide some kind of nonlinear compensation when necessary. Gain scheduling, or more recently scheduling of multiple linear models (Banerjee et al., 1997; Johansen and Foss, 1997; Narendra et al., 1995), probably is the most widely used scheme in process industries. One of the reasons is that it mimics the look-up table approach (e.g., using different controller settings as the operating condition changes) in industrial practice. In order to provide nonlinear compensation, the following information becomes important:
  1. 1.

    linearized model at a given operating point

  2. 2.

    description of process nonlinearity



Titration Curve Continuous Stir Tank Reactor Feed Flow Rate Load Response Step Decrease 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Cheng-Ching Yu
    • 1
  1. 1.Department of Chemical EngineeringNational Taiwan University of Science & TechnologyTaipeiTaiwan

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