Modal Analysis of Ring Gyroscope

陀螺儀的發展至今已數十年，由於一個對稱元件在高速旋轉下，其方向不會改變的特性因而被廣泛應用於飛機、艦艇及衛星等軍事用途上，至現在更發展應用於汽車及電玩等民生工業；而陀螺儀的種類也由初期轉子式陀螺儀演變成現今振動式或光纖式陀螺儀。 不同於傳統轉子式陀螺儀，振動式陀螺儀具有使用期限較長且啟動時間短等優點；因而現行所使用及研究的陀螺儀多以振動式陀螺儀為主；振動式陀螺儀其結構上的設計形式也分為許多種類，包括音叉式、樑式及半球殼等，本研究中之陀螺儀以金屬圓環為主體，由壓電材料來驅動及感測，探討陀螺儀振動之振型及模態分析；進而讓此陀螺儀達到持振與節點抑制，以利將來可使用力平衡方式判定角速度與感測電壓間的關係。 根據實驗的結果，可以確定其第一共振頻率模態及此環的第一共振頻率數值，於此研究中並且利用設計之回授電路讓此環形陀螺儀達到持振與抑制節點振動，而往後也將使持振及抑制節點的振動頻率一致並減少雜訊的干擾，方便未來使用力平衡方式來檢測角速度訊號。Research of Gyro has been developed for many years. It is used on airplane、ship and satellite for military affairs a long time ago then now it is applied to car or game industry and kinds of gyro evolved from rotor gyro into vibrating gyro or fiber gyro. The paper primarily study vibrating gyro because that can improve restrictions of rotor gyro including life and time of switch. There are all kinds of vibrating gyro include tuning fork gyro, rod gyro and hemispheres, and in this paper, the study main apply metallic ring which is driven and sense by piezoelectric material. So it can make the vibrating gyro vibrate without input signal and restrain vibrating in the node which can use force-balance method to check angular velocity between voltages in the future. According to experiment result, it can make sure the first natural frequency of the vibrating ring-gyro and design feedback circuit to let the ring vibrate without inputting signal in the first natural frequency and restrain to vibrate in the node. From the result, the metallic ring can achieve my demands. It must improve signal in the circuit and reduce affect from noise which will make for sensing angular velocity between voltages with force-balance method in the future.目 錄謝..........................................................................I文摘要....................................................................II錄...........................................................................III目錄.......................................................................IV目錄.......................................................................V一章 導論 1.1 前言.......................................................................1 1.2 文獻回顧.................................................................1 1.3 本文目的與內容簡介................................................2二章 環形陀螺儀振動控制原理 2.1 環形陀螺儀運動方程是推導與自然共振頻率............4 2.1.1 圓環動能..........................................................6 2.1.2圓環應變能.......................................................8 2.1.3圓環支撐徑度與應變能........................................8 2.1.4圓環的運動方程式與自然共振頻率.......................11 2.2 振動陀螺儀力平衡量測模式及其角速度量測............12 2.2.1力平衡量測模式的振動控制................................13 2.2.2力平衡量測模式時的角速度量測...........................15 2.3 壓電陶瓷材料驅動與感測特性.................................15 2.4 回授激發持振迴路原理與控制.................................17 2.4.1 作動原理.............................................................18 2.4.2 回授電路............................................................19 2.4.3 反相放大器..........................................................20 2.4.4 二階bessel濾波器.................................................21 .5 抑制節點振動迴路原理與控制................................23三章 環形陀螺儀之實驗............................................25 3.1環形陀螺儀之模態測試架構.....................................25 3.2迴授激發持振迴路設計之實驗架構............................32 3.3迴授電路圖設計........................................................35.4 抑制節點振動迴路實驗架構與迴路設計......................38四章 實驗結果與討論...................................................40.1 環形陀螺儀模態測試..................................................40 4.2 回授激發持振與抑制節點實驗結果...............................63五章 結論與展望...........................................................67考文獻號說