Systems and methods for securing a remotely operated vehicle (ROV) to a subsea structure during cleaning, maintenance, or inspection of the structure surface are provided. In one or more embodiments, an attachment mechanism includes a pair of grasping hooks that are raised and lowered when driven by a motorized drive. In one or more embodiments, an attachment mechanism includes a rigid holder having a mechanical stop and connected to a swing arm, the swing arm configured to rotate inward, but not outward beyond the mechanical stop. In one or more embodiments, an attachment mechanism includes a plurality of linked segments in series, each connected at a plurality of pivot points. A pair of wires passes through the plurality of linked segments and connects to a pair of pulleys that extend or retract the wires, thereby rotating the plurality of linked segments.

A process is disclosed in which a computing device reads electronic data from an ultrasonic scanning probe and processes that data in real time to determine if any potential weld defects are encountered as the probe head moves along scanning the weld. The method receives weld scan data in the form of scanning slices and determines if any of the encountered indications match a predetermined criterion. The process utilizes a moving scan data window of scan slices and processes each window for indications of weld defects. The processing of the data window is optimized using a rule-based, indications counting set so that any found defect indications triggers the issuance of a signal to an operator, in various forms, such as activating a marking module, issuing an alert signal, or printing a report.

In the system, two ultrasonic transducers, which form a pair and each have a piezoelectric ceramic plate-shaped element with a rectangular geometry, can be fastened to a surface of a component. The two ultrasonic transducers are arranged at a distance from one another such that there is no direct mechanical contact and they are arranged beside one another with a parallel orientation of their central longitudinal axes. The two elements have a different polarization along their width and are connected with the same polarity to an electrical voltage source. The two plate-shaped elements can also have an identical polarization along their width and can be connected in this case with opposite polarity to an electrical voltage source. At least one ultrasonic transducer and/or at least one further ultrasonic transducer is/are designed to detect ultrasonic waves reflected by defects and/or shear waves simultaneously emitted by the two ultrasonic transducers.

A method for determining a quality of a friction stir welded seam is described. The method involves applying an impact to a welded plate and comparing its damping capacity with the damping capacity of a geometrically equivalent defect-free plate. Damping capacities that differ by a small percent difference indicate that the welded plate is also defect-free. This method is particularly advantageous when dealing with small defects, which produce miniscule changes in natural frequency which may not be measureable.

A method for determining a quality of a friction stir welded seam is described. The method involves applying an impact to a welded plate and comparing its damping capacity with the damping capacity of a geometrically equivalent defect-free plate. Damping capacities that differ by a small percent difference indicate that the welded plate is also defect-free. This method is particularly advantageous when dealing with small defects, which produce miniscule changes in natural frequency which may not be measureable.

A method for determining a quality of a friction stir welded seam is described. The method involves applying an impact to a welded plate and comparing its damping capacity with the damping capacity of a geometrically equivalent defect-free plate. Damping capacities that differ by a small percent difference indicate that the welded plate is also defect-free. This method is particularly advantageous when dealing with small defects, which produce miniscule changes in natural frequency which may not be measureable.

Systems and methods for securing a remotely operated vehicle (ROV) to a subsea structure during cleaning, maintenance, or inspection of the structure surface are provided. In one or more embodiments, an attachment mechanism includes a pair of grasping hooks that are raised and lowered when driven by a motorized drive. In one or more embodiments, an attachment mechanism includes a rigid holder having a mechanical stop and connected to a swing arm, the swing arm configured to rotate inward, but not outward beyond the mechanical stop. In one or more embodiments, an attachment mechanism includes a plurality of linked segments in series, each connected at a plurality of pivot points. A pair of wires passes through the plurality of linked segments and connects to a pair of pulleys that extend or retract the wires, thereby rotating the plurality of linked segments.

Provided is a method of manufacturing an outer joint member of a constant velocity universal joint, which is constructed by forming a cup section having track grooves, and a shaft section, and by welding a cup member and a shaft member, the method including: forming the cup member and the shaft member of medium carbon steel; preparing a cup member having a cylindrical portion and a bottom portion integrally formed by forging, and a joining end surface in a machining step; preparing a shaft member having a joining end surface formed in a machining step; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; welding the cup member and the shaft member by radiating a beam; and performing, after the welding, an ultrasonic flaw detection-inspection step.

A system for detecting cracks in an underwater structure can include an acoustic signal transmitter configured to be disposed proximate to, but without physically contacting, the underwater structure, where the acoustic signal transmitter is configured to emit acoustic signals. The system can also include an acoustic field receiver configured to be disposed proximate to, but without physically contacting, the underwater structure, where the acoustic field receiver is configured to receive resulting acoustic fields. The system can further include a controller that is configured to receive the resulting acoustic fields from the acoustic field receiver. The controller can also be configured to analyze the resulting acoustic fields signal. The controller can further be configured to detect, based on analyzing the resulting acoustic fields, a crack in the underwater structure.

A buoyancy module for use with a water environment robotic system of the type having an underwater robotic vehicle having a winch has a buoyancy configuration which can be selectively altered. The system includes a module that is configured to be repeatedly, selectively buoyantly engaged and buoyantly disengaged with the underwater robotic vehicle. A tether is connected to the module and is extendable and retractable in response to operation of the winch. Extending and retracting the module can buoyantly engage or buoyantly disengage the buoyancy module with the underwater robotic vehicle according to the operation of a state controller. By engaging and disengaging the buoyancy module, the buoyancy of the underwater robot can be selectively altered. A method is also disclosed.