工具機傳動系統動態分析與振動抑制方法之研究

邱淑瑞(SHU-JUI CHIU)

指導教授 ： 蔡孟勳

國立中正大學/工學院/機械工程學系/碩士(2014年)

摘要

近年來，工具機對於高速高精的要求愈來愈高，在高速化的過程中，無疑地會激發出結構與傳動共振，針對結構撓性效應的議題，本論文考慮插補器、伺服迴路與傳動等系統，以建立出具傳動系統之撓性效應之完整伺服迴路，藉由推導撓性結構誤差方程式，鑑別出撓性結構特性參數，最後會透過利用前插補加減速設計，以找出最佳之鐘型加速度時間，有效的抑制激發出結構共振的頻率，達到不需要外加感測器並能達到高速高精度的目的。
　　本論文首先針對傳動系統動態模型之建立進行介紹，其次則對所建立的模型進行相關的分析。在建立動態模型的內容部分可分為兩個主題：第一個部份為假設傳動系統為剛體，建立出完整的伺服迴路。第二個部分則是透過能量法的推導撓性結構模型，並加入伺服迴路的系統以得到包含傳動以及底座撓性結構的伺服迴路系統模型。透過此系統模型，我們討論了軸向變形以及驅動工作平台產生之反作用力與底座之間的關係，並對此系統進行撓性結構誤差分析以及誤差方程式推導。並進一步討論encoder回授以及光學尺回授之差異。經由單軸平台實驗驗證，撓性結構動態模擬之誤差與實驗所得到的結果相當近似，誤差方程式亦可用來鑑別結構的特性參數，包含質量、阻尼以及剛性，並經由敲擊實驗以得到底座的結構參數。
　　最後一個部分則是利用前插補加減速的設計來降低結構共振的影響，調整最佳的鐘型加速度時間抑制激發出結構共振的頻率。經由實驗結果得知，我們推導的模型能夠準確地預測共振與加減速時間的關係。

關鍵字

傳動系統

並列摘要

In recent years, for high-speed high-precision machine tools, the structure resonance of drive feed system could be excited. In include the flexible effect, this thesis considers the design of interpolator, drive feed systems and servo loop by deriving the complete drive feed system model which includes the servo loop and structure response. The structure error equation is derived and used to identify the parameters of the flexible structure. Finally, the model can be utilized to determine the optimal bell shape deceleration ACC/DEE time. Through choosing the proper time constant, the vibration from structural resonance can be suppressed effectively. The proposed method can achieve high speed and high precision without using an external sensor and the method can achieve the objective of high speed and precision.
First, this thesis introduces the derivation of dynamic drive feed system model and the second part is to perform dynamic model analysis. The main content can be divided into two scheme. The first part assumed that drive feed system is a rigid body and the complete servo loop model is integrated. The second part is to derive the flexible structural model using energy method. Through this model, the axial deformation of the flexible structure is estimated and relationship between the base and the reaction force is established. The error equations of the flexible structure which describes the differences between encoder feedback and optical measurement feedback is derived. Experiments of uniaxial platform are conducted to validate the dynamic error equation which is then used to identify the structure parameters, including mass, damping, and rigidity.
The last part is to design the interpolation parameter so that the impact of structural resonance can be reduced. By adjusting the best bell-shaped acceleration time, the resonance frequency of the excitation of the structure can be reduced. The experimental results validate the derived equation can predict the dynamic response accurately.

參考文獻

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