Fiber Optic Position Transducer Using Magnetostrictive Material
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Solution Overview
Problem
Existing position transducers face challenges such as mechanical alignment issues, sensitivity to angular misalignment, and limitations in multiplexing, especially in harsh environments like deep wells, due to their reliance on interferometry or light intensity methods.
Innovation Solution
A fiber optic position transducer using magnetostrictive material and Fiber Bragg Grating Sensors, which measures changes in wavelength caused by relative magnetic field displacements, allowing for robust, multiplexed, and temperature-compensated position measurements without physical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If interferometry-based fiber optic transducers are used, then measurement precision is improved, but device complexity increases due to mechanical alignment requirements and sensitivity to angular misalignment
Solution Approach 1:
The patent replaces the mechanical alignment system with a magnetic field-based sensing system. Instead of using optical mirrors and beams that require precise mechanical alignment, the invention uses a magnetostrictive material that responds to magnetic field changes, eliminating the need for complex mechanical alignment mechanisms while maintaining measurement precision
Solution Approach 2:
The patent changes the measurement parameter from optical path length (interferometry) to magnetic field strength (magnetostriction). By measuring changes in magnetic field strength caused by displacement of the magnetic element, the system achieves position measurement without the alignment sensitivity inherent in optical interferometry methods
2Device complexity
If light intensity-based transducers are used, then device complexity is reduced, but measurement precision deteriorates due to sensitivity to angular misalignment and surface reflectivity
Solution Approach 1:
The patent replaces the light intensity measurement system with a magnetic field-based magnetostrictive sensing system. This substitution eliminates the need for reflective surfaces and angular alignment while providing more stable and precise position measurements through magnetic field interactions with the magnetostrictive material
3Adaptability or versatility
If traditional position transducers are used in harsh environments, then adaptability is improved, but reliability deteriorates due to wear and electromagnetic interference
Solution Approach 1:
The patent replaces mechanical contact-based transducers with a magnetic field-based sensing system using magnetostrictive material. This eliminates physical contact and wear between moving parts, significantly improving reliability in harsh environments while maintaining adaptability through the non-contact magnetic field measurements
Solution Approach 2:
The patent introduces magnetostrictive material as an intermediary between the magnetic field source and the measurement system. This intermediary material translates mechanical displacement into magnetic field changes, enabling non-contact position sensing that is resistant to wear and electromagnetic interference in harsh environments
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 solution provides high sensitivity, resistance to harsh conditions, and precise position measurements with reduced wear and electromagnetic interference, suitable for deep well applications like flow control valves.
Implementation Method 1
Magnetostriction, that occurs in the majority of cases with ferro-magnetic materials, is a variation in the length of a segment subject to a magnetic field; the magnetostrictive material expands or contracts in response to changes in the strength of the magnetic field in the area where the segment is found.
Implementation Method 2
at least two Fiber Bragg Grating Sensors; wherein at least one of said two sensors is fixed to said at least one segment of magnetostrictive material
Data Source
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AI summary
Fiber optic position transducer that includes a magnetic or electromagnetic element, one or more segments of magnetostrictive material, Fiber Bragg Grating Sensors, a rod of material that is impenetrable to magnetic fields, optical fiber. One or more of the sensors is fixed upon a segment of magnetostrictive material, which is fixed to a rod, and may only be displaced longitudinally. The Fiber Bragg Grating Sensors have different wavelengths and are made of the same optical fiber. The magnetic or electromagnetic element included may be made of NdFeB (Neodymium Iron Boron) or metal alloys of TbDyFe (Terbium, Dysprosium and Iron), such as TX, Terphenol-D and others. It is applied to a control flow valve in an oil well, and it also refers to the calibration process of the position of the transducer.