Feature Selection for Unmanned Surface Vehicle Fault Diagnosis Research and Experimental Verification

Unmanned Surface Vehicle Thruster Fault Diagnosis via Vibration Signal Wavelet Transform and Vision Transformer under Varying Rotational Speed Conditions

“… Signifies the vibration caused by imbalance, while represents the structure’s dynamic stiffness. The magnitude of vibration caused by rotor imbalance is proportional to the imbalance mass and the square of the angular velocity [ 46 ]. The vibration frequency corresponds to the rotational speed of the body, denoted as the first-order vibration, fundamental vibration, 1X component, etc.…”

“…In prior studies involving FDD USV, extensive analyses were conducted on data parameters such as rotational speed, power consumption, supply voltage, and vibration to determine thruster malfunctions due to external causes. It was determined through experimental validation that, among these parameters, vibration presented the highest degree of sensitivity for fault identification [ 46 ]. Further research in FDD USVs also involved the application of dimension reduction and entropy-based numerical transformation techniques for each fault case [ 47 ].…”

“…When factors such as propeller blade damage, temporary obstructions, or biological fouling occur, they cause a shift in the center of gravity away from the geometric center aligned with the propeller blade’s rotational axis. This shift results in a misalignment of the geometric center, leading to an imbalance in the rotating body [ 46 ]. This rotational imbalance acts as a vibromotive force, which is then transmitted through the structural components of the hull and detected by vibration sensors mounted inside.…”

Research on Clustering-Based Fault Diagnosis during ROV Hovering Control

“…To apply data-based techniques, it is crucial to select appropriate fault features for underwater thrusters. According to prior research on underwater thruster FD, RPM and current data were used as fault features to diagnose propeller breakage and entanglement situations [20]. It is anticipated that changes in the area of contact with the fluid due to propeller breakage or entanglement result in torque variations [34].…”

“…The objective is to identify faults caused by external factors-particularly entanglement with floating debris and propeller breakage, which are among the most frequently occurring [19]. According to previous FD studies, the consumption current and rotation speed (in revolutions per minute, RPM) of underwater thrusters were selected as fault features for FD under normal conditions, propeller breakage, and entanglement [20]. A qualitative data-based approach was used to analyze the relationships between these different unit elements and faults.…”