Experimental Validation of a Model-Free High-Order Sliding Mode Controller with Finite-Time Convergence for...

Area of Science:

• Robotics
• Control Systems Engineering
• Marine Technology

Background:

• Trajectory tracking for Autonomous Underwater Vehicles (AUVs) often relies on model-based controllers requiring extensive parameter knowledge.
• Existing finite-time controllers offer robustness but lack user-defined convergence times, limiting energy efficiency.
• Predefined convergence times are crucial for optimizing AUV energy consumption and mission planning.

Purpose of the Study:

• To experimentally validate a novel model-free, high-order Sliding Mode Controller (SMC) for AUVs.
• To demonstrate finite-time convergence with a user-predefined convergence time.
• To assess the controller's suitability for cooperative missions with limited communication.

Main Methods:

• Implementation and experimental testing of a model-free high-order Sliding Mode Controller (SMC).
• Introduction of a time-base parameter for precise control over convergence time.
• Comparative analysis against Proportional-Integral-Derivative (PID) and asymptotic convergence SMC.

Main Results:

• The proposed controller successfully guided the AUV to desired depth and heading trajectories within the predefined time.
• Significant error reduction observed: up to 75% compared to PID and 41% compared to asymptotic SMC.
• Demonstrated substantial energy savings: 35% reduction versus PID and 50% versus asymptotic SMC.

Conclusions:

• The model-free high-order SMC with predefined finite-time convergence is experimentally validated for AUV trajectory tracking.
• This controller offers superior performance in terms of accuracy and energy efficiency compared to traditional methods.
• The controller is well-suited for cooperative AUV missions, even under restricted communication conditions.