壓電式圓柱型振動陀螺儀之設計與分析

Design and Analysis of a Piezoelectric Cylinder type of Vibratory Gyroscope

黃吉松(Ji-Song Huang)

指導教授 ： 丁鏞

中原大學/工學院/機械工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500716

摘要

本篇論文的研究方向為設計製作一尺寸小但具有高靈敏度之圓柱型振動陀螺儀，振動陀螺儀首重是否具有較佳的靈敏度，因此本文即探討科氏力以及極化時之電場強度對靈敏度的影響分析，由有限元素分析軟體ANSYS進行模態分析，找出第一及第二模態以做為圓柱型陀螺儀驅動源與感測源。另外亦比較圓柱型陀螺儀與方樑型、三角樑型、音叉型之陀螺儀的優缺點，由結果發現由於圓柱型陀螺儀具有結構相對稱的特性，故第一與第二模態之共振頻率會相當近似，進而使得其靈敏亦相對的提升。而由ANSYS針對圓柱型陀螺儀的直徑與長度、圓柱表面壓電電極之寬距與間距的各項不同設計參數分析得知，較小的圓柱直徑較易獲得較佳的極化電場，而較大的圓柱直徑則需要再增加極化電壓才能獲得完全極化的效果；另外具有相同之電極寬距與間距，亦可獲得較佳之極化電場。
在本論文中亦討論中間材質為金屬外層貼附壓電片與整根皆使用壓電陶瓷之優缺點，利用ANSYS模擬分析其特性，發現採用整根皆使用壓電陶瓷設計之圓柱型陀螺儀具有較佳之科氏力影響、較高之靈敏度、防鏽以及低雜訊干擾之影響，故其性能良好。在圓柱型陀螺儀之實驗過程中，顯示驅動與感測之共振頻率幾乎為一致；而在旋轉實驗中得到轉速與感測電壓擁有良好的線性關係，亦指出該陀螺儀在中低轉速下擁有較佳之線性關係。

關鍵字

圓柱型振動陀螺儀 ； 極化電場 ； 靈敏度 ； 模態分析

並列摘要

A small size but high-sensitivity cylinder-type vibratory gyroscope is designed and analyzed in this article. The principle of the vibratory gyroscope including the Coriolis effect, the sensitivity, and the polarization and so on are introduced. Modal analysis by ANSYS to search 1st flexural mode usually used for the resonant frequency of the driving resource and 2nd flexural mode usually used for the resonant frequency of the sensing resource for different shape are carried out. As compared with the square type and the triangle type and fork type, the resonant frequency of the driving and the sensing resources are quite similar mainly because of the structural symmetry, thus it indicates it will have better sensitivity. Various sets of the diameter and the length of the cylinder type, and the width and the clearance of the cylindrical surface for polarization is investigated and simulated by ANSYS, it indicates the geometry of the cylinder with small diameter will easily obtain high polarized electric field; and the equivalent width and clearance gains better electric field, thus has better polarization.
Also, instead of using the metal body attached with piezoelectric ceramics, entire body made of piezoelectric ceramics with polarization and silver paste is introduced, which has advantages of consistent characteristics, Coriolis force effect, good sensitivity, antirust and less noise disturbance. From the simulation by ANSYS, the entire body made of piezoelectric ceramics verifies its good performance. In practical experiment on a ceramic cylinder gyroscope, it shows that the resonant frequency is quite approximate to the simulated one. A good linear relation of the sense voltage to rotation speed is obtained, which indicates the piezoelectric ceramic cylinder gyroscope is good at the measurement for low and medium rotation speed.

並列關鍵字

sensitivity ； modal analysis ； polarized electric field ； Cylinder-type gyroscope

參考文獻

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