Motion Compensated Pile Guide Hybrid Control
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Solution Overview
Problem
Existing motion compensated pile guide systems for floating vessels face challenges in maintaining control as monopile penetration depth increases, due to excessive forces caused by inclination angles from wave and current forces, irregular soil structures, and position control inaccuracies, leading to potential actuator overload and loss of motion control.
Innovation Solution
The system incorporates sensors to determine monopile inclination and actual force, with a control unit that adjusts the actuator's movement to apply a desired force opposite or in the same direction as the actual force, using a hybrid control technique that combines motion and force control to maintain acceptable forces and prevent actuator overload.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the pile guide position is displaced to reduce the inclination angle, then the monopile orientation is improved, but the motion control may run out of its operating range or push the vessel out of range due to excessive force
Solution Approach 1:
The control method dynamically adjusts the pile guide position based on the relationship between inclination angle reduction and force increase. By monitoring these parameters in real-time and adjusting the displacement magnitude, the system optimizes the balance between correcting monopile inclination and maintaining actuator operating range, preventing excessive forces that would push the vessel out of range
Solution Approach 2:
The system continuously monitors both the monopile inclination angle and the force exerted on the pile guide. This dual feedback mechanism allows the control unit to adjust the pile guide displacement in real-time, ensuring that inclination correction actions do not generate excessive forces that would exceed actuator capabilities or push the vessel out of its motion control range
2Productivity
If the monopile penetration depth increases, then the monopile installation progress is improved, but the forces between the monopile and gripper increase to an unacceptable level due to decreased hinge effect and control inaccuracy
Solution Approach 1:
The control system transitions from static position control to dynamic hybrid control that adapts to changing penetration depth. As the monopile penetrates deeper and the hinge effect decreases, the system dynamically adjusts the control strategy by incorporating force feedback and adjusting displacement magnitude, allowing continued operation without excessive forces despite the reduced natural stabilization
Solution Approach 2:
The system proactively monitors force levels and inclination angle changes during the penetration process. By detecting trends in force increase before they reach unacceptable levels, the control unit can adjust the pile guide displacement strategy in advance, preventing excessive forces from developing as penetration depth increases and the hinge effect diminishes
Data Source
AI summary
A system for controlling a motion compensated pile guide for a floating vessel comprises a pile guide for guiding a monopile in its longitudinal direction during driving the monopile into a seabed, an actuator for moving the pile guide in horizontal direction with respect to a vessel to which the pile guide is mounted, a control unit for controlling the actuator, which control unit is configured for compensating motion of the vessel to which the pile guide is mounted so as to maintain the horizontal position of the pile guide during driving a monopile into a seabed, a first sensor for determining an inclination angle of a monopile with respect to the vertical during driving the monopile into a seabed, and a second sensor for determining magnitude and direction of an actual force of a monopile onto the pile guide during driving the monopile into a seabed. The control unit is configured to determine a desired force of the pile guide onto the monopile for minimizing the inclination angle when determined by the first sensor, and to control the actuator for moving the pile guide opposite to the direction of the actual force when the desired force is larger than the actual force and in the same direction as the actual force when the actual force is larger than the desired force.