Parameters Tuning of Reduced-Order Active Disturbance Rejection Control

Reduced-order active disturbance rejection controller (RADRC) treats the controlled plant as a cascade integral model, assuming as little information about the plant as possible. However, if more information of the plant is known, we can use this information in the design to improve the control performance. This paper proposes a new RADRC parameter tuning method. The proposed method starts from generalized active disturbance rejection control (GADRC) with known plant information, and then the parameters of an RADRC is obtained by approximation with the GADRC. According to the fact that the feedback controllers of RADRC and GADRC have the same zeros, the RADRC parameters are computed on the premise that they have similar disturbance rejection performance. In the proposed method, the RADRC parameters are expressed in the form of bandwidth, which is the most commonly used tuning method for RADRC, thus they are easy to be retuned online. Combing the advantage of both RADRC and GADRC or other controllers, RADRC can be expected to achieve the desired performance with convenience.