Active Disturbance Rejection Controller Extended State Observer

The implementation of an Active Disturbance Rejection Controller (ADRC) and Extended State Observer (ESO) constitutes a critical component in modern control system design for various engineering applications. These control elements employ sophisticated algorithms to accurately estimate and compensate for both internal uncertainties and external disturbances within dynamic systems. Using discrete-time modeling approaches, the control system can effectively handle sampling effects, digital implementation constraints, and mitigate the impact of measurement noise and system disturbances. The ESO algorithm typically involves state-space formulations where unmodeled dynamics and external disturbances are treated as an extended state variable, estimated through observer dynamics and subsequently canceled via control law compensation. This discrete implementation enables practical digital controller deployment with features like fixed-step integration, z-domain transformations, and real-time disturbance rejection capabilities. These characteristics make ADRC with ESO particularly suitable for demanding control applications across diverse industries including aerospace, automotive systems, precision manufacturing, and robotic control, where robustness against uncertainties and disturbances is paramount.