磁致伸縮感測器應用於金屬輪廓感測的設計與實現

Design & Implementation of Metal Profile Detection Based on Magnetostrictive Sensor

華惟抒(Wei-Shu Hua)

指導教授 ： 吳文中

共同指導教授 ： 王威智(Wei-Chih Wang)

國立臺灣大學/工學院/工程科學及海洋工程學研究所/博士(2013年)

https://doi.org/10.6342/NTU.2013.01991

摘要

近年來由於光纖技術與磁致伸縮材料的迅速發展，使得光纖與磁致伸縮感測技術已廣泛的應用在各個工業上。本論文主要在描述以馬克-詹德光學式干涉儀(Mach-Zehnder interferometer)為架構的感測系統，並以新研發之磁致伸縮材料(Magnetostrictive material) 作為磁場與金屬的感測元件，論文中也著重在磁致伸縮材料研發與其應用在磁場與金屬輪廓感測的設計與建置。本論文所研發之磁致伸縮感測器為在光纖的感測臂採用披覆結構，在感測臂黏合具有磁致伸縮效應(Magnetostriction)的材料。其主要的感測方式是利用磁致伸縮效應發生在光纖干涉儀的光相位變化來感測磁場與金屬物件。當感測臂之光纖受一外加磁場作用後，其披覆之磁致伸縮材料將受磁場影響而產生磁致伸縮效應，進而使磁致伸縮材料產生應變，最後導致光路產生相位調變，透過分析輸出光強度的變化，進而得知磁場受金屬干擾所產生的變化，本論文所研發之磁致伸縮材料對於磁場靈敏度約為70.7x10-3 rad/gauss。本論文所研發之金屬感測器不同於過去傳統的金屬感測器，有效克服目前傳統金屬感測器的感測限制，不僅可提供即時且高零敏度的感測，藉由量測系統為光學架構的優勢，可有效避免傳統金屬感測器常面臨的電磁波干擾。本論文被證實可成功的將磁致伸縮材料作為磁場感測與金屬探測的感測元件，並可進一步辨識各類複雜形狀之金屬與其輪廓，亦是首例將磁致伸縮材料應用在金屬感測的元件。除此之外，本論文所研發之磁致伸縮感測器其運用在金屬感測時可達到1cm2的空間辨識率。論文中除了探討磁致伸縮材料的特性，也會詳細介紹磁場感測與金屬偵測的機制，量測實驗系統的建置與量測結果分析。本研究除了證實自行研發之磁致伸縮材料整合光學式干涉儀後可應用於磁場感測外，更可實現金屬偵測與金屬表面輪廓的感測，亦說明磁致伸縮材料可提供多樣與創新性的感測應用。

關鍵字

磁致伸縮效應 ； 磁致伸縮感測器 ； 金屬感測器

並列摘要

This dissertation describes the design and construction of a magnetostrictive composite-fiber-optic Mach-Zehnder interferometer capable of magnetic field and metal profile measurement. Unlike previous metal detectors, the sensor makes use of the magnetostriction effect on a fiber-optic interferometer to detect metallic objects. The metal detector overcomes many difficulties existing in conventional metal detectors. Aside from offering relatively high sensitivity (sensitivity of about 70.7x10-3 rad/gauss), the optical detection provides resistance to RF interference which is common in typical electromagnetic type metal detectors. The magnetostrictive sensor is also relatively compact and able to achieve a minimum spatial resolution of 1cm2 for metal profile detection. This dissertation will introduce the detailed design and application of this fiber-optic magnetostrictive sensor in magnetic field measurement and metal detection. In the course of study, a new ferromagnetic polymer based on magnetostrictive material and detection techniques were developed. Configuration and optimization of the sensors is also studied in the context of designing sensors capable of achieving greater sensitivity (70.7x10-3 rad/gauss).

並列關鍵字

magnetostrictive effect ； magnetostrictive sensor ； metal detector

參考文獻

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