Ship Roll Vibration Detection via Heave Phase Analysis
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Solution Overview
Problem
Existing methods fail to reliably and efficiently detect the early risk of roll vibrations building up in watercraft, particularly during resonance, which can lead to large roll angles and instability, especially in submarines and container ships.
Innovation Solution
A method that records and relates lifting and rolling movements to detect the proximity to roll movement resonance by monitoring roll angles, their time derivatives, rolling power, and energy, allowing for early detection of impending roll vibrations through continuous and repeated measurements at short intervals, and using a buoyancy map to determine the moment of lift and pitch angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If roll angle monitoring is performed continuously to detect roll vibration risk early, then detection precision is improved, but measurement complexity and data processing requirements increase
Solution Approach 1:
The monitoring system segments the roll angle measurement into specific phases of the heave motion (ascending vs. descending portions). By analyzing roll angles only during these critical phases and comparing them, the system achieves early detection of roll vibrations without requiring continuous complex processing of all motion data, thus reducing overall system complexity while maintaining detection precision.
Solution Approach 2:
The system performs preliminary analysis by comparing roll angles during ascending and descending heave portions before critical roll vibrations fully develop. This preliminary detection during normal operation phases allows early warning of resonance conditions, enabling preventive action before large roll angles occur, thereby improving detection precision without requiring complex real-time processing during critical events.
2Reliability
If heave and roll motion parameters are continuously monitored and related to each other, then reliability of resonance detection is improved, but use of energy and computational load increase
Solution Approach 1:
The system employs periodic action by monitoring roll angles at specific intervals during heave cycles (during ascending and descending portions) rather than continuous monitoring. This periodic sampling during critical phases maintains reliable detection of resonance conditions while significantly reducing energy consumption and computational load compared to continuous parameter correlation analysis.
3Speed
If roll angle measurements are taken at very short time intervals to capture early vibration signs, then detection speed is improved, but device complexity and data processing requirements increase
Solution Approach 1:
The system performs preliminary detection by analyzing roll angle differences during ascending and descending heave portions before critical roll vibrations fully develop. This approach enables early detection of resonance trends without requiring extremely high-speed continuous monitoring, achieving fast detection through strategic phase-based sampling rather than high-frequency continuous measurement, thus improving detection speed while limiting system complexity.
Data Source
Figure 1
AI summary
In the method for detecting the state of movement of a watercraft with respect to a rolling motion resonance of the watercraft, at least the lifting motion and the rolling motion are detected and related to one another while traveling, wherein the rolling angle and/or its temporal progression is/are detected for a predetermined part of the lifting motion and/or wherein the rolling power and/or its temporal progression is/are determined and/or wherein the rolling energy and/or its temporal progression is/are determined.