本研究探討具高線性度的渦電流位移偵測器之設計。渦電流探頭為纏繞於磁芯的電感器與陶瓷電容組成的LC共振電路，驅動電路為以石英振盪器與混波器等元件組成的交流阻抗偵測電路。由理論與實驗的共振曲線擬合結果發現，導電性目標物的距離會影響感測探頭的電感值與寄生電阻，因而影響共振頻率，使其在固定激發頻率下測得的阻抗下降。渦電流位移偵測器的線性度，可由並聯電容的選擇達成最佳化。本研究所研發之感測器能對導電性與磁性目標物作非接觸動態位移量測，將可應用於生產線自動化檢測與機械運動控制。

In this study , the design of the highly linear eddy-current displacement detector is investigated. The sensor head is a LC resonating circuit consists of a ferrite-cored wire-wound inductor and a ceramic capacitor. The driving circuit is an ac impedance measurement circuit constructed from several elements, including crystal oscillator, analog mixer, etc. According to the fitting results of theoretical and experimental resonance curves, the distance of conducting target affects both the inductance and the parasitic resistance of the sensor. For the reducing target distance, the change in inductance alters the resonance frequency, which results in the change in impedance of LC circuit under the fixed excitation frequency. The linearity of the sensor can be optimized by tuning the capacitance in parallel. The developed sensor is capable of dynamic measurement of the distance for conducting and magnetic targets, which is important for automation and motion control applications.

摘要 i
ABSTRACT ii
誌謝 iii
目錄 iv
表目錄 v
圖目錄 vi
圖目錄 vi
第一章 前言 1
1.1 研究背景 1
1.2 研究目的與動機 1
1.3 文獻回顧 2
第二章 實驗原理與方法 4
2.1 渦電流效應 4
2.2 位移偵測器原理 5
2.3 LC共振特性 6
第三章 位移偵測器之設計研製 8
3.1 設計與研製流程 8
3.2 探頭設計與製作 9
3.3 驅動電路設計與製作 12
3.4 位移感測器特性測定 19
第四章 實驗結果與討論 21
4.1 渦電流探頭阻抗與頻率的關係 21
4.2 電壓對距離的關係 25
4.2.1線性度 26
4.2.2 靈敏度 28
4.3 解析度 30
4.4 穩定性分析(溫度效應) 32
第五章 結論 35
參考文獻 36
附錄 A 38
附錄 B 39

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