Practical Prescribed-Time Control for Underactuated Marine Surface Vessels: Theory and Experiment

This paper proposes a practical prescribed-time control strategy for underactuated marine surface vessels (UMSVs) with fore-aft asymmetry. A sufficient condition for practical prescribed-time stability (PPTS) is established through a novel time-varying gain function that maps the settling time into a single user-defined parameter. First, the nonholonomic constraint of the UMSV is transformed into an integral cascade system via the hand position approach, which addresses the design challenge from underactuation. Subsequently, input saturation nonlinearity is approximated by a sigmoid function, while model uncertainties are compensated through an adaptive parametric design paradigm. A barrier function-integrated adaptive law is further developed to bound the adaptive parameter without overestimation. Rigorous stability analysis confirms that the tracking error converges to an adjustable bounded domain within the prescribed time. Experimental results validate the efficacy of the proposed controller. Note to Practitioners—Controlling underactuated marine surface vessels (UMSVs) with asymmetric hull designs is challenging for time-sensitive operations such as autonomous navigation. Existing methods often require manual tuning to meet strict deadlines, which limits their reliability. To address this issue, we propose a practical prescribed-time control strategy that guarantees the tracking error converges to a tunable region within a user-defined time. By introducing a practical time-varying gain function, the controller achieves precise control over the settling time, thereby enhancing better reliability for real-time applications. This approach improves the efficiency and performance of UMSVs in dynamic environments. It can be extended to other autonomous systems requiring time-critical control. The experimental dataset is available at: https://github.com/zdh58324488/Experimental-Dataset-for-UMSV-Control