Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1810
標題: 球面誤差模型於雷射位移探頭誤差補償之研究
A Study of Error Compensation for Laser Displacement Sensor by Spherical Error Model
作者: 盧怡廷
Lu, Yi-Ting
關鍵字: Alignment;校準;Laser Displacement Probe;Coordinate Measuring Machine;Error Analysis;雷射探頭;三次元量床;誤差分析
出版社: 機械工程學系
摘要: 
本研究利用量測一三角錐來校準雷射探頭的位置與方位,使得雷射探頭與觸發式探頭於三次元量床上有共同的參考座標。
由於待測工件表面斜率對雷射探頭量測精度具有嚴重的影響,故本研究提出量測一標準球來求出各量測點的誤差與影響因素,將量測數據利用非線性回歸程式擬合出球面誤差模型的各個係數後,並進一步補償誤差以提升整個量測系統的精度。此外本研究也發現在量測三角錐時若是未補償因平面斜率所導致之量測誤差時,則三角錐頂點會有一偏移量產生導致校準誤差,因此吾人補償量測三角錐時的誤差,並重新計算探頭的位置與方位以及重新獲得球面誤差模型。
相較於傳統量測一斜面來取得擬合數據的方法,本研究具有誤差取得容易、能廣泛獲得不同斜率對誤差的影響,以及實驗器材架設方便等優點。
因此本研究結合雷射探頭的座標校準與球面誤差模型後,即可對三維的自由曲面執行精確的量測。最後分別利用觸發式探頭與雷射探頭來量測一三維自由曲面,並以觸發式探頭所量得的結果為基準來驗證雷射探頭量測的精確度。

This paper proposes a novel technique of laser displacement probe alignment with the coordinate measuring machine (CMM). Measuring a pyramid artifact that resides at a specific location with the touch trigger probe and the laser displacement probe, the position and the orientation of the probe is calibrated by using the proposed techniques.
When laser displacement probe is used for profile measurement, the accuracy will be seriously affected by the gradient of the surface of an object. This paper presents a spherical error model to account for them. The parameters of this model are estimated by measuring a standard sphere and analyzing these data by means of nonlinear regression. The experimental results show that the model is satisfactory and the measurement errors after compensated are reduced dramatically. Because we do not consider the error of alignment procedure, we compensate error for measuring the pyramid artifact and acquire the new position and the new orientation of the probe. After that, we measure the standard sphere to obtain the spherical error model again.
There are two advantages in our approach compared with the calibration scheme by measuring an inclined plane. These advantages are to acquire error of any gradient more easily and to build the experiment setup more conveniently.
Finally, we measure a 3D free-form surface by the touch trigger probe and the laser displacement sensor respectively. The accuracy of the laser displacement sensor is verified with comparing the result of the measurement by each other.
URI: http://hdl.handle.net/11455/1810
Appears in Collections:機械工程學系所

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