On Stability Analysis of Active Disturbance Rejection Disturbance Control for General MIMO Motion Control Systems

In this paper, the tracking control problem is considered for general Multi-input multi-output (MIMO) motion systems with internal uncertainty and external disturbance. The extended state observer is used not only to estimate and compensate the "total disturbance", but also to force the closed-loop systems to have desired characteristics. The size of control input gain matrix uncertainty dealt with by ADRC is quantitatively given. It is proven that the tracking error can be small enough by tuning the bandwidth of the ESO. The simulation results demonstrate that the desired performance of the control system can be achieved despite external disturbance and nonlinear uncertainties.