Offshore Motion Compensation Platform with Three-Point Support
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Solution Overview
Problem
Existing motion compensation platforms for offshore crane operations are complex and inefficient in counteracting vessel movements, particularly for tall objects, leading to potential damage from water-induced motion during load transfer.
Innovation Solution
A motion compensation platform with a base attachable to a vessel, featuring a bearing frame supported by a three-point system including a hinged, fixed support and telescopic supports forming an x-y actuator system, equipped with sensors and control systems to adjust the bearing frame's position and counteract vessel movements, thereby minimizing angular and positional changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complicated Stewart platform with six-point support is used to compensate for water movement, then motion compensation capability is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the necessary motion compensation functions (heave, roll, pitch) from the complete six-degree-of-freedom Stewart platform. By removing unnecessary degrees of freedom and simplifying the support structure to three points instead of six, the system achieves adequate motion compensation with reduced complexity.
Solution Approach 2:
The patent applies different support characteristics to different locations: one fixed hinged support provides stable rotation reference, while two telescopic supports provide active motion compensation. This localized differentiation optimizes the overall system performance without requiring uniform complexity throughout.
2Manufacturing precision
If telescopic supports are used to adjust vertical distance for angular position control, then motion compensation precision is improved, but power requirements increase
Solution Approach 1:
The patent uses only two telescopic supports instead of three or more, providing just sufficient adjustment capability to control the angular position of the bearing frame. This partial action approach achieves the necessary precision without excessive power consumption that would result from over-engineering the system.
3Stability of the object's composition
If a fixed support is used to define predetermined distance, then structural stability is improved, but adaptability to motion compensation decreases
Solution Approach 1:
The patent creates an asymmetric support configuration with one fixed hinged support and two telescopic supports. This asymmetry allows the fixed support to provide stable rotational reference while the telescopic supports handle active motion compensation, optimizing both stability and adaptability through differentiated roles.
Data Source
AI summary
An assembly includes an object with a vertical height of at least 30 metres placed on a bearing frame and a motion compensation platform including a base attached to a vessel. The platform includes an x-y actuator system for rotating the bearing frame with respect to the base about an x-axis and a y-axis, a sensor system configured to detect an x-axis rotating movement, and a y-axis rotating movement, and to generate a corresponding sensor signal, as well as an x-y control system configured to adjust the position of the bearing frame with respect to the base, depending on the sensor signal. The bearing frame is supported at a vertical distance above the base by means of a three-point support having a hinged, fixed first support and hinged second and third supports which are telescopic in the longitudinal direction of the z-axis.