Active Disturbance Rejection Control: from ODEs to PDEs**This work was carried out with the support of the National Natural Science Foundation of China and the National Research Foundation of South Africa

This paper introduces a new emerging control technology, known as active disturbance rejection control to this day. We start its main idea and two main parts, namely, extended state observer and extended state observer based feedback for lumped parameter systems, and then discuss its application to both state and output feedback stabilization for distributed parameter systems.