A Robust Control via a Fuzzy System with PID for the ROV

Area of Science:

• Robotics
• Control Systems Engineering
• Ocean Engineering

Background:

• Remotely operated vehicles (ROVs) face challenges in depth control due to environmental uncertainty and system nonlinearity.
• Existing control methods often struggle with robustness in complex underwater conditions.

Purpose of the Study:

• To develop an advanced control scheme for enhancing ROV depth control performance.
• To improve the robustness and motion capabilities of ROVs in challenging aquatic environments.

Main Methods:

• A novel interval type-2 fuzzy proportional-integral-derivative (IT2FPID) control scheme was developed.
• The IT2FPID controller integrates principles of proportional-integral-derivative (PID) control and interval type-2 fuzzy logic control (IT2FLC).
• Performance was evaluated using key indicators assessing immunity to external disturbances.

Main Results:

• The IT2FPID controller demonstrated superior robustness compared to traditional PID and type-1 fuzzy proportional-integral-derivative (T1FPID) controllers.
• Achieved an overshoot of only 0.3% and a settling time of 7.5 seconds.
• The controller effectively mitigated external disturbances, enhancing system stability.

Conclusions:

• The developed IT2FPID controller offers a robust solution for ROV depth control in uncertain and nonlinear underwater environments.
• This advanced control strategy significantly enhances ROV operational performance and reliability.
• IT2FPID presents a promising advancement over conventional control methods for marine robotics.