Modified Active Disturbance Rejection Control for Improved Performance

Abstract

This paper proposes a modified active disturbance rejection control (ADRC) scheme for improved dynamic performance. A modified extended state observer (ESO) based on desired closed loop dynamics is constructed to estimate and discard the effect of unknown system dynamics and disturbances. Simple tuning rules are presented based on existing bandwidth parameterization method. Effectiveness of the proposed scheme is demonstrated through simulation study conducted on a variety of process models. The proposed scheme exhibits better tracking performance as well as disturbance attenuation than ADRC despite having same controller and observer bandwidths. Furthermore, the compact form of modified control scheme significantly reduces design and implementation complexity.