Active disturbance rejection control of chemical processes

In this paper a novel control strategy, the active disturbance rejection control (ADRC), is applied to the representative process control problems. In the ADRC framework, the disturbance and unmeasured dynamics associated with chemical processes are treated as an additional state variable, which is then estimated and compensated for in real time. This reduces a normally complex, time-varying, nonlinear, and uncertain dynamic process to an approximately linear, time-invariant, cascade-integral form, where a simple proportional-derivative (PD) controller suffices. Simulation studies are performed on two nonlinear continuous stirred tank reactors (CSTR), both demonstrate very good performance in the absence of an accurate mathematical model of the process..