Active disturbance rejection control: From an enduring idea to an emerging technology

This paper introduces an emerging technology called active disturbance rejection control (ADRC), and a story that spans East to West in geography and centuries in time. Emerges from ADRC is the idea that shadowed the ancient Chinese invention of the south-pointing chariot, the idea embedded in a Frenchman´ invention of isochronous governor from the early 19^th Century, and the very same idea of invariance formalized in the 1939 Soviet Union. The idea was again revived in the 1990s in the form of ADRC and was soon spread to the U.S., where it took roots and gradually matured into a viable industrial control technology, as evident in the recent adoptions by major industrial concerns. Also seen in ADRC is the clashing of ideas in the history of control science, the ideas that go back to H.S. Tsien and R. Kalman in the 1950s. The origin and the making of ADRC can only be understood from the interplay of the big ideas as presented in this paper. Subject to scrutiny were the basic problems, the fundamental assumptions, and the very conception of control science itself. It is the disagreement on the very foundation of our craft that makes a paradigm-shift to ADRC seem inevitable, in theory and in practice.