Tuning ADRC for Multi-Variable System Based on Existing PID Parameters

Thanks to the long-time engineering practice, the existing PID controllers and their parameters contain the valuable information about the models of the industrial processes. Such information is absorbed to simplify the design and tuning process of the active disturbance rejection controller (ADRC) in this study. If one channel of the multi-variable system is stabilized by PID, then ADRC can be built to replace the PID scheme, and the ADRC parameters can be calculated from the PID parameters. This technique can be operated channel by channel until all channels are stabilized by ADRC, which is verified by simulations. Moreover, the simulations imply that the presented ADRC design and tuning method can generate the feasible parameters efficiently for the plants with unknown models.