Pipe Joint Transfer Hook Yaw Control for Offshore Alignment
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Solution Overview
Problem
The offshore transfer of pipe joints between a pipe carrier vessel and a pipe laying vessel is challenging due to the instability caused by waves, requiring precise control of yaw rotation and alignment, posing risks to operators and causing operational delays and damages.
Innovation Solution
A system with a spreader bar equipped with motor-driven flywheels and a crane control system that automatically controls the lifting, yaw rotation, and alignment of pipe joints using tugger lines and winches, minimizing manual intervention and enhancing stability and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual rigging and pipe joint connection methods are used, then operators can directly handle the pipe joints, but the risk of collision and injury to operators increases due to vessel instability caused by waves
Solution Approach 1:
The patent introduces an automated rigging system with spreader bars and robotic manipulators as intermediaries between the crane and the pipe joints. This eliminates direct human contact with the pipe joints during transfer operations, removing operators from the hazardous zone where vessel instability could cause collisions and injuries.
2Reliability
If automated control systems are implemented to reduce manual intervention, then operational safety improves, but device complexity increases
Solution Approach 1:
The automated rigging system is designed as a multi-functional integrated platform that combines crane control, spreader bar positioning, robotic manipulation, and real-time monitoring capabilities. This universal system handles multiple tasks (lifting, positioning, aligning, and transferring pipe joints) through a single coordinated control architecture, managing complexity through functional integration rather than separate dedicated systems for each task.
3Speed
If the crane boom is made longer to reach pipe joints at greater distances, then transfer speed improves, but the risk of pipe joint collision and damage increases due to greater sway and instability
Solution Approach 1:
The patent employs dynamic positioning systems and active control mechanisms that continuously adjust the crane boom angle, spreader bar position, and robotic manipulator movements in real-time. This dynamic adaptation compensates for the increased sway and instability inherent in longer boom operations, maintaining precise control over the pipe joint throughout the transfer trajectory to prevent collisions and damage.
Solution Approach 2:
The system incorporates real-time feedback from sensors that monitor the position, orientation, and motion of the pipe joint, spreader bar, and crane boom. This feedback is continuously processed by the control system to make immediate adjustments to the transfer operation, correcting deviations caused by wave-induced vessel motion and preventing the pipe joint from swinging into obstacles or the vessel structure.
4Manufacturing precision
If multiple tugger lines are used to control yaw rotation, then rotational precision improves, but the number of components and system complexity increases
Solution Approach 1:
The yaw rotation control system is segmented into multiple independent tugger lines, each responsible for controlling rotation in specific directions. This segmentation allows for precise, differential control of the spreader bar's rotational movement by independently adjusting the tension in each tugger line, achieving high rotational precision through coordinated action of multiple simplified control elements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system ensures stable orientation and controlled rotation of pipe joints, reducing the risk of collisions and operator injuries while increasing operational efficiency and reducing capital and operational costs.
Implementation Method 1
one or more motor driven flywheels (32), each rotating about a dedicated flywheel axis (33), and an electrically controlled flywheel adjusting system (34) for adjusting an orientation of the flywheel axis (33) with respect to the spreader bar (13) to generate (due to the obtained gyroscopic effect) and apply a yaw rotation moment
Implementation Method 2
one or more motor driven lifting winches (12) for winding and unwinding the lifting ropes (10) and thereby lifting and lowering the spreader bar (13)
Implementation Method 3
two or more motor driven tugger winches (19) for winding and unwinding two or more tugger lines (20) that can be extended with a horizontal distance (21) to each other and with a non-zero horizontal direction component from the two or more tugger winches or hoists (19) to one of the crane hook (11) and spreader bar (13) and connected thereto
Data Source
Figure 1A~1B
Figure 2A~2D
Figure 2E
AI summary
A system (1) for the offshore crane transfer of pipe joints (2) comprises a pipe carrier vessel (3), a pipelay vessel (4), a boom crane (7) on the pipelay vessel (4), a crane hook (11) comprising a base portion (15) a hook portion (16) rotatable with respect to the base portion (15) by a yaw adjusting motor (18), a crane control system (25) automatically controlling the yaw adjusting motor (18) to rotate the hook portion (16) together with a spreader bar (13) about a vertical yaw rotation axis (17), the spreader bar (13) comprising electrically controlled pipe connectors (26) to engage the pipe joint (2) and connect the pipe joint (2) to the spreader bar (13), the base portion (15) of the crane hook (11) forms at least two lifting rope attachment seats (28) horizontally spaced apart by at least a minimum horizontal lifting rope distance (29) of more than 2 meters, at least two lifting ropes engaging the two lifting rope attachment seats (28) and extending from the lifting rope attachment seats (28) upward to a crane boom (8) with at least said minimum horizontal lifting rope distance (29) therebetween, rigging ropes (14) extending between the crane hook (11) and the spreader bar (13) at a rigging rope angle (30) to the horizontal in the range of 40° and 55°.