Model matching control in an improved discrete-time ADRC using the zero-order hold considering input-side disturbance

In this paper, we propose an approach for designing a discrete-time model matching active disturbance rejection control (ADRC). The ADRC is a design method that achieves a high performance for disturbance estimation and compensation using an extended state observer (ESO), which estimates the plant state variables and generalized perturbation and then offsets it. However, when the input-side disturbance is added, steady-state errors may occur in the control system. So we propose a design method that estimates the state variables, generalized perturbation, and plant input-side disturbance in a discrete-time system. Moreover, the output converges to that of the reference model for longer sampling times using a zero-order hold discretization. Furthermore, our proposed method is applied to model matching control. In simulation studies, it is shown that the proposed method is effective for some plants. The effectiveness of the proposed method is further confirmed by applying it to a DC motor.