Disclosed are a method, a device, equipment and a medium for dynamic positioning of a semi-submersible offshore platform. The method includes: acquiring a real-time position of the platform; if the real-time position is different from a preset position, detecting an external force torque by a first torque detector; calculating a first target thrust produced by each of propellers, controlling the propellers to produce forces according to a first target thrust torque, and detecting an actual thrust torque; obtaining a fault condition of each of the propellers if the actual thrust torque is different from the first target thrust torque, indicating that the propellers have faults; recalculating a thrust of each of the propellers, a second target thrust torque, according to the fault condition, the external force torque and the preset formula set; and controlling each of the propellers to generate the thrust according to a corresponding second target thrust torque.

Disclosed is a deepwater platform welded joint testing system. The testing system comprises a host unit, a hydraulic unit and a control unit, wherein the control unit is connected with the host unit and the hydraulic unit respectively; the host unit comprises a bearing frame placed on a bearing base, biaxial tension/compression loading oil cylinders mounted on the bearing frame, a lateral force resistant mechanism connected to the front ends of the biaxial tension/compression loading oil cylinders, counter-force supports fixed to the top end of the bearing frame and biaxial bending loading oil cylinders mounted on the counter-force supports. According to the deepwater platform welded joint testing system, through the independent or synergistic effect of the six loading oil cylinders, stretching and fatigue performance tests of a large complex structure under uniaxial tension/compression, uniaxial bending, biaxial tension/compression, biaxial bending and uniaxial/biaxial tension/compression and bending composite loads can be achieved.

Disclosed is a deepwater platform welded joint testing system. The testing system comprises a host unit, a hydraulic unit and a control unit, wherein the control unit is connected with the host unit and the hydraulic unit respectively; the host unit comprises a bearing frame placed on a bearing base, biaxial tension/compression loading oil cylinders mounted on the bearing frame, a lateral force resistant mechanism connected to the front ends of the biaxial tension/compression loading oil cylinders, counter-force supports fixed to the top end of the bearing frame and biaxial bending loading oil cylinders mounted on the counter-force supports. According to the deepwater platform welded joint testing system, through the independent or synergistic effect of the six loading oil cylinders, stretching and fatigue performance tests of a large complex structure under uniaxial tension/compression, uniaxial bending, biaxial tension/compression, biaxial bending and uniaxial/biaxial tension/compression and bending composite loads can be achieved.

A system includes a data communication module, a position sensor, and a controller. The position sensor is operable to detect a position of a watercraft. The controller is configured or programmed to send at least one of functional information, trouble information, or operational information to an external computer through a data communication module. In the functional information, an automatic control function of a marine propulsion device and the position of the watercraft when the automatic control function is used are associated with each other. In the trouble information, a trouble in the marine propulsion device and the position of the watercraft when the trouble occurred are associated with each other. In the operational information, an operational pattern performed by a user for the marine propulsion device and the position of the watercraft when the operational pattern is performed are associated with each other.

A marine propulsion device information transmitting and receiving system includes a watercraft and a server. The watercraft includes an engine and a controller to control the engine. The controller encrypts an operating time of the engine and data related to the engine with an encryption key associated with information unique to the engine. The watercraft includes a communicator to transmit the information unique to the engine, the encrypted operating time of the engine, and the encrypted data related to the engine to the server. The server decrypts the encrypted operating time of the engine and the encrypted data related to the engine with the encryption key associated with the information unique to the engine, and determines whether or not the decrypted data related to the engine are genuine based on the decrypted operating time of the engine.

A marine propulsion device information transmitting and receiving system includes a watercraft and a server. The watercraft includes an engine and a controller to control the engine. The controller encrypts an operating time of the engine and data related to the engine with an encryption key associated with information unique to the engine. The watercraft includes a communicator to transmit the information unique to the engine, the encrypted operating time of the engine, and the encrypted data related to the engine to the server. The server decrypts the encrypted operating time of the engine and the encrypted data related to the engine with the encryption key associated with the information unique to the engine, and determines whether or not the decrypted data related to the engine are genuine based on the decrypted operating time of the engine.

The present disclosure provides a system and method for monitoring a floating vessel hull mooring system by determining one or more hull rotational motions of yaw, roll, and/or pitch that do not require independent knowledge of environmental conditions. The hull rotational motion of a secure and intact mooring system can be calculated and/or established experientially over time by measuring movement of the hull to characterize the hull rotational motion at given geographical positions. A compromised mooring system will result in different hull rotational motion of at least one of yaw, roll, and/or pitch. By monitoring the hull rotational motion for a given geographical position to be compared to the theoretical values (and/or previous recorded values), it is then possible to assess that at least a portion of the mooring system has been compromised and in at some embodiment indicate which portion of the mooring system has been compromised.

The present disclosure provides a system and method for monitoring a floating vessel hull mooring system by determining one or more hull rotational motions of yaw, roll, and/or pitch that do not require independent knowledge of environmental conditions. The hull rotational motion of a secure and intact mooring system can be calculated and/or established experientially over time by measuring movement of the hull to characterize the hull rotational motion at given geographical positions. A compromised mooring system will result in different hull rotational motion of at least one of yaw, roll, and/or pitch. By monitoring the hull rotational motion for a given geographical position to be compared to the theoretical values (and/or previous recorded values), it is then possible to assess that at least a portion of the mooring system has been compromised and in at some embodiment indicate which portion of the mooring system has been compromised.

Methods and apparatus for inspecting an underwater vehicle. In embodiments, a system receives a SAR image for at least a portion of an exterior surface of an underwater vehicle and performs CCD processing to compare a baseline SAS image for the underwater vehicle with the received SAR image of the underwater vehicle to generate a CCD output corresponding to a measure of similarity of the baseline SAS image and the received SAS image. The system determines whether there was tampering of the underwater vehicle based on the measure of similarity.

Methods and apparatus for inspecting an underwater vehicle. In embodiments, a system receives a SAR image for at least a portion of an exterior surface of an underwater vehicle and performs CCD processing to compare a baseline SAS image for the underwater vehicle with the received SAR image of the underwater vehicle to generate a CCD output corresponding to a measure of similarity of the baseline SAS image and the received SAS image. The system determines whether there was tampering of the underwater vehicle based on the measure of similarity.