本論文將發展一套以PZT壓電材料為基礎的聲波發送與接收系統，激發出在板中的導波(蘭姆波)，比對蘭姆波理論與實驗的吻合程度，且以此為基礎，設計一套可行的觸控辨識方法。
模擬上，由COMSOL有限元素軟體建構模型，模擬電壓輸入PZT壓電材料後震動產生蘭姆波，經過板中傳遞後由另一端PZT輸出電壓值，再經由本研究自創的等效面積法，將三維模型轉為二維軸對稱模型進行模擬，大幅降低模擬時間，且與真實訊號做比對，觀察相似程度。
應用上，測試不同輸入頻率與輸入波形產生之蘭姆波對於手指觸控之敏感度，找出適合的蘭姆波頻率、波形與模態。再設計一種針對於觸控辨識的PZT壓電片配置方式，利用蘭姆波傳時遭遇手指之穿透與反射訊號差異，配合理論蘭姆波群速度計算與自製演算法分析，反推手指觸控位置，定位手指中心準確度 2.3 mm。

This thesis developed an ultrasound signal receiving and transmitting system based on piezoelectric transducers made of PZT ceramics. One of the transducers can excite Lamb waves in a thin plate and others can detect the Lamb wave signals. Both phase and group velocity of the excited Lamb waves can be calculated and then compared with experimental data. This Lamb wave ultrasound system will be applied to a touching panel to sense the position of human’s fingers.
In theoretical simulation, a commercial finite element software COMSOL Multiphysics® is adopted to optimize the performance of this PZT-based Lamb wave transmitting/receiving system. A quasi-2D effective area method has been developed and tested in order to reduce the computing time to an originally 3D problem in wave physics. Good results are obtained and are well in agreement with experimental data.
For the application on touching and positioning panel sensors, this thesis studied the sensitivity and signal differences in Lamb waves when finger is touching at different positions of the plate. Optimal operating frequency and mode of Lamb waves are determined first both theoretically and experimentally. A configuration of deploying several PZT transducers on the plate and an algorithm for processing the received signal waveform are established for locating the position of finger tip touched on the plate. It shows that we can locate the position with an accuracy of 2.3 mm.

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