Active disturbance rejection controller design for distributed parameter systems

A control problem of dynamic processes described by partial differential equations (PDE´s) is proposed and studied in this paper. They are linear distributed parameter models. The inputs of the models discussed are position-independent. As is known to all, distributed parameter systems always demand high tracking precision and good stability. However, it is difficult for classical approaches to achieve a high performance in disturbance rejection. Active disturbance rejection controller (ADRC) has great ability of resisting disturbance and could meet the demand of fast-track. In order to ensure the system output converging to the reference value, ADRC controller is designed. Extended state observer (ESO) is a key part of ADRC and a reasonable designed ESO can improve the performance of ADRC. In this study, the Gaussian approximation is used to design a higher order ESO to eliminate the model uncertainty and total disturbance. Simulation results indicate that ADRC controller is superior to traditional PI controller both in terms of set-point tracking and disturbance rejection.