Global fixed-time prescribed performance control with fixed-time distributed state observer for non-cooperative...

Area of Science:

• Robotics
• Control Systems Engineering
• Marine Engineering

Background:

• Cooperative tracking of non-cooperative targets by multiple unmanned surface vehicles (USVs) is challenging in complex marine environments.
• Existing methods often face limitations due to initial condition dependencies and external disturbances.

Purpose of the Study:

• To develop a robust fixed-time cooperative tracking control strategy for multiple USVs targeting a non-cooperative entity.
• To address limitations of initial state conditions and external disturbances in USV tracking systems.

Main Methods:

• A novel fixed-time distributed state observer (FDSO) was designed for target state estimation, independent of initial conditions.
• A global fixed-time prescribed performance control strategy incorporating an exponential fixed-time shift function (EFSF) was proposed.
• A fixed-time dynamic compensation (FDC) mechanism was introduced to counteract external disturbances.

Main Results:

• The proposed FDSO accurately estimates target states without relying on initial conditions.
• The control strategy ensures prescribed performance and eliminates initial error condition restrictions.
• The FDC mechanism effectively mitigates the impact of external disturbances on system performance.
• Lyapunov stability analysis confirmed the practically fixed-time stability of the closed-loop system.
• Simulations demonstrated fast convergence, high tracking accuracy, and robustness.

Conclusions:

• The developed fixed-time control strategy provides a robust and efficient solution for cooperative target tracking by USVs.
• The approach guarantees rapid convergence of tracking errors within a fixed time, outperforming traditional methods.
• This research contributes to advancing autonomous marine systems' capabilities in complex operational scenarios.