Command Filter-Based Adaptive Predefined-Time Tracking Control for Uncertain Systems With Disturbance Compensation

Abstract

For uncertain nonlinear systems characterized by parameter uncertainties and unmodeled disturbances, an adaptive predefined-time tracking control strategy is investigated in conjunction with disturbance observers. First, parameter uncertainties are addressed via predefined-time adaptive laws, and a novel disturbance observer is devised to dynamically compensate for unmodeled disturbances. Subsequently, a predefined-time controller employing predefined-time filters is formulated based on the command-filtered backstepping control framework. The proposed controller mitigates the “complexity explosion” issue and ensures continuous control signals during the control process. Theoretical analysis confirms that the proposed controller guarantees the tracking error converges to a small vicinity around zero within a predefined time, while the system's convergence time is arbitrarily predeterminable, irrespective of the system parameters. Ultimately, the validity of the developed controller is confirmed through two simulation examples.