Towards a turnkey solution of industrial control under the active disturbance rejection paradigm

The potential of active disturbance rejection control (ADRC) as a viable solution to industrial control has become increasingly evident after the recent adoptions by major industrial concerns, chiefly because of its ability of disturbance rejection and its independence of a detailed mathematical model of the plant. With the controller and observer bandwidths in ADRC largely determined a priori by the design specifications, and with the order of the plant largely known for major classes of industrial processes, the only parameter the user needs is the gain in the input channel that characterizes the proportional relation between the input signal and the derivative of the process output of certain order. This normally slow changing process parameter is denoted here as the critical gain parameter (CGP). This paper is concerned with the task of estimating CGP and regularly updating it in the ADRC, thus making it possible for the controller to be set up, tuned, and commissioned with a single stroke of a key by the industry personnel. The proposed approach integrates the classic ADRC with an extremum seeking-based parameter estimation of the CGP and it greatly expands the operation range and the robustness of the ADRC-based approach, relieving the designer from the tedious task of empirical tuning. An illustrative simulation example is provided to validate the proposition.