| 摘要: | 滾珠螺桿進給系統一直是精密機械及工具機的重要零組件，其預壓衰退會影響加工精度，本研究目的在於應用頻譜分析及適應性階次追蹤技術，將不同預壓狀態(4%、1%預壓及12um背隙)滾珠螺桿進行特徵歸納，作為狀態監測時診斷依據。本論文涵蓋範圍分為四部分，(1)實驗平台及監測(資料擷取系統建置)：進行內循環滾珠螺桿的單軸進給實驗平台設計製作，藉由高低頻採樣訊號同步擷取系統收集運轉所產生的振動、轉速、溫度及扭矩等訊號；(2)適應性階次追蹤技術探討：探討權重因子和參數Q1之特性及對於適應性角速度馮卡曼濾波階次追蹤(Adaptive Angular Velocity Vold-Kalman Filter Order Tracking, Adaptive AV VKF_OT)之訊號分析影響；(3)實驗規劃及數據收集：實驗模式分為變速及等速往返運轉，各模式收集 42筆資料(1組)，實驗螺桿共有5支，其中3支為不同預壓狀態，以建立判斷基準，另2支原為4%預壓，藉由調珠分別改為1%預壓及12um背隙，作為驗證，共有3組基準及4組驗證資料；(4)訊號分析與探討：藉由頻譜、階次分析與特徵值計算，主要探討預壓狀態與螺桿振動之關係，另也對溫度與扭矩訊號初步的說明，即當預壓較大時，其所需之驅動扭矩較大及溫升狀態也趨於明顯。本研究透過使用頻譜分析選取特定範圍計算其球通頻率(Ball Pass Frequency, BPF)及邊頻能量與Adaptive AV VKF_OT提取特定範圍的BPF所對應之球通階次(Ball Pass Order, BPO)，藉著權重因子調整，可以改變階次追蹤頻寬，分別將BPF與其加邊頻波形提取出來計算其能量並相減，以達到量化邊頻能量之目的，為免除元件差異性導致不客觀比較，定義邊頻比，藉由管制圖方法制定閥值並驗證所提出方法之可靠性。定義並計算相近因子(S)以表達驗證資料之狀態，以變速運轉為例，驗證資料4%(2類)、1%與12um背隙，其S分別為1.093、0.919、2.406、1.464，相較於其他資料為最小值，可看出能將驗證資料歸類到其所屬的狀態。從結果得知，頻譜分析及Adaptive AV VKF_OT的運算在等速運轉的情況下皆能顯現出個別狀態下邊頻比差異，使狀態差異最大化，有助於滾珠螺桿狀態監測。但如機台處於變速運轉操作模式，必須以Adaptive AV VKF_OT提取特徵，以彌補頻譜分析因BPF隨著轉速變化平均地分散在各頻段中，而無法明顯判別之情況。;The ball screw feeding system has been an important component of precision machinery and tooling machines, and its preload degradation will affect the machining accuracy. The purpose of this study is to apply the spectrum analysis and adaptive order tracking technology to generalize the characteristics of ball screws with different preload conditions (4%, 1% preload and 12um backlash) as a basis for diagnosis during condition monitoring. The scope of this thesis is divided into four parts; (1) experimental platform and monitoring (data acquisition system construction): The single-axis feeding experimental platform of the internal circulation ball screw is designed and manufactured. Then the signals of vibration, speed, temperature, and torque generated by the operation are collected by the high and low frequency sampling signal synchronization acquisition system; (2) Adaptive order tracking technology exploration: To investigate the characteristics of the weighting factors and Q1 parameters and their effects on Adaptive Angular Velocity Vold-Kalman Filter Order Tracking (Adaptive AV VKF_OT); (3) Experimental planning and data collection: The experimental modes were divided into variable speed and constant speed back and forth operation, and 42 datas (1 set) were collected for each mode; there were 5 experimental ball screws in total, 3 of which were in different preload states to establish the baseline; the other 2 were originally in 4% preload, but were subsequently changed to 1% preload and 12um backlash by adjusting the balls, which were used as validation data; (4) Signal analysis and investigation: The relationship between the preload state and the screw vibration was investigated by spectrum, order analysis and characteristics calculation, and the temperature and torque signals were preliminarily explained. That is, when the preload is large, the required driving torque is large and the temperature rise state tends to be obvious. In this study, the ball pass frequency (BPF) and sideband energy of a specific range are calculated by using the spectrum analysis and the ball pass order (BPO) corresponding to the BPF of a specific range is extracted by Adaptive AV VKF_OT, and the weighting factor is adjusted to change the order tracking bandwidth. The BPF and its plus sideband waveforms are extracted and their energy is calculated and subtracted to achieve the purpose of quantifying the sideband energy. Define and calculate the similarity factor (S) to express the state of the verification data. Using the variable speed operation as an example, the validation data 4% (2 kinds), 1% and 12um backlash, the S are 1.093, 0.919, 2.406, 1.464, respectively. Compared with other data, it is the smallest value, and it can be seen that the validation data can be classified into the state to which it belongs. From the results, it was found that both spectrum analysis and Adaptive AV VKF_OT can reveal the difference of the sideband ratio in individual states under constant speed operation to maximize the state difference, which is helpful for ball screw condition monitoring. However, if the machine is running at a variable speed. The Adaptive AV VKF_OT can extract the required characteristics to compensate for the situation where the BPF is not clearly discernible because it is evenly dispersed in each frequency band with change of rotation speed. |
