Ship Hull Magnetization Determination Using Computational Modeling
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Solution Overview
Problem
Existing methods for regulating a ship's magnetic signature are disrupted by secondary magnetic sources within the ship, leading to inaccurate magnetization measurements and signatures, as sensors inside the hull are affected by these sources, resulting in a low signal-to-noise ratio and inaccurate representation of the ship's real magnetic field.
Innovation Solution
A method involving a device with magnetic field sensors glued close to the hull and immunization loops that adjust electric currents to minimize the magnetic signature, using a computational unit to model and solve equations for magnetization distribution and signature calculation, focusing on tangential magnetic induction components to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are placed inside the hull far from the hull surface, then the magnetization determination is stable and less noisy, but the measurements become unrepresentative of the actual magnetic field due to interference from secondary magnetic sources within the ship
Solution Approach 1:
The patent introduces an intermediary computational model that processes sensor measurements to reconstruct the magnetization distribution. The model acts as a mediator between the noisy sensor data and the actual magnetic field characteristics, using mathematical relationships to extract accurate magnetization information despite the presence of secondary magnetic sources.
Solution Approach 2:
The patent creates a virtual model (copy) of the magnetization distribution on the hull surface based on sensor measurements. This computational copy allows accurate representation of the magnetic field characteristics without requiring physical sensors to be positioned in ideal locations, thus resolving the contradiction between measurement stability and accuracy.
2Measurement precision
If sensors are brought closer to the hull surface, then the signal-to-disturbance ratio improves, but the determined signature no longer corresponds to the actual ship signature
Solution Approach 1:
The computational model serves as an intermediary that corrects the measurements taken close to the hull. It processes the high-resolution data to reconstruct the far-field signature, ensuring that the determined signature accurately represents the actual ship signature despite the close sensor positioning.
Solution Approach 2:
The patent transforms the measurement parameters from direct local field values to reconstructed magnetization distribution and far-field signature. This parameter transformation allows the system to utilize close-proximity measurements while producing accurate far-field signature predictions.
3Measurement precision
If sensors are positioned close to the hull to reduce interference from secondary magnetic sources, then measurement accuracy improves, but the complexity of the measurement system increases
Solution Approach 1:
The patent uses computational copying to create a virtual representation of the magnetization distribution from processed sensor data. This approach maintains measurement accuracy while reducing the need for complex physical sensor arrangements, as the computational model handles the complexity of data integration and reconstruction.
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
This approach provides a robust, real-time determination of the ship's magnetization and signature, reducing interference from secondary magnetic sources and enhancing the accuracy of magnetic immunization, thereby improving the ship's magnetic signature regulation.
Implementation Method 1
acquiring a plurality of measurements of a magnetic field, by means of a plurality of sensors
Implementation Method 2
The circulation of a current in a loop generates a magnetic field which is superimposed on the local terrestrial magnetic field and on the field created by the distribution of magnetization on the shell
Implementation Method 3
calculate the most probable magnetization distribution on the surface of the shell by using a first model which associates a magnetization distribution with a plurality of measurements of the magnetic field
Data Source
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AI summary
The invention relates to a method which consists of taking a plurality of measurements of the magnetic field using the plurality of sensors; assessing the inductive magnetic excitation; and determining the likely distribution of magnetic sources on the surface of the hull by resolving a system of equations derived from modelling the physical phenomena at play, on the basis of the plurality of measurements taken and the assessed inductive magnetic excitation. The model describes the induced magnetic sources as a distribution of dipolar sources and the remanent magnetic sources as a distribution of monopolar sources. The invention further relates to a device (6) for determining the magnetisation of the hull of a ship for implementing the method.