Dynamic hovering for uncrewed underwater vehicles via an error-separation-based cooperative strategy

Area of Science:

• Robotics
• Ocean Engineering
• Control Systems

Background:

• Uncrewed underwater vehicles (UUVs) are crucial for ocean resource utilization but face challenges in precise maneuvering due to environmental uncertainties and disturbances.
• Existing control methods often struggle to balance robustness, efficiency, and precision in dynamic subsea environments.

Purpose of the Study:

• To develop a novel cooperative control framework for UUVs to enhance precision and efficiency in dynamic hovering missions.
• To minimize control efforts associated with sliding mode control (SMC) while maintaining robustness.
• To address challenges posed by uncertainties, time-varying disturbances, and unstructured subsea environments.

Main Methods:

• Introduction of a cooperative control framework integrating Linear Quadratic Regulator (LQR) and Sliding Mode Control (SMC).
• Development of a deviation separation strategy to decouple hovering deviations into task-specific and anti-disturbance components using an influence function.
• Real-time disturbance estimation and adaptive compensation without prior knowledge.

Main Results:

• The proposed framework effectively minimizes control efforts and enhances robustness for long-duration dynamic hovering.
• The deviation separation strategy enables accurate real-time disturbance estimation and compensation.
• Cooperative control between LQR and SMC avoids performance conflicts, improving compensation accuracy and energy efficiency.
• Demonstrated effectiveness in countering current perturbations while maintaining high-precision hovering with low control costs.

Conclusions:

• The novel cooperative control strategy significantly advances UUV control capabilities for complex underwater tasks.
• The framework offers a versatile solution for achieving precise, efficient, and robust UUV operations in challenging marine environments.
• This approach provides a pathway for improved ocean resource utilization through enhanced UUV performance.