Parameter tuning for decentralized low-order active disturbance rejection control scheme

Many industrial processes are multi-input multi-output (MIMO) systems, of which the order and/or the relative degree are uncertain, and the parameters cannot be obtained accurately. In many studies, the decentralized low-order active disturbance rejection control (ADRC) scheme is employed for such MIMO systems. For such cases, a necessary condition for the stability is given based on the relation between the parameter b_Ei and the numerator´s zero-order coefficient (NZC) matrix. It is also proved that the low-order ADRC scheme with proper parameters can reject the interaction disturbance and guarantee the closed-loop stability. Based on the corresponding tuning method, the design procedure is illustrated on the plants with/without the time delay. The simulation results indicate that the tuning method is applicable to the ADRC based on the low-order extended state observer (ESO).