光纤棒机床自动定位与对准装置

The Automatic Location and Alignment Device for Optical Fiber Preform Machine Tools

针对现有光纤棒沉积机床同轴调试中存在对准耗时长和精度低等问题,设计并实现了一套高精度、高稳定性的光纤棒机床自动定位与对准装置。首先通过张正友标定法消除镜头的径向畸变与切向畸变,接着采用高斯滤波、动态阈值法和Canny边缘检测提取准确的图像边缘,消除噪声和背景对后续处理的影响,最后使用新型弧分段圆形检测算法实现图像中被测面中心的精确定位,确定图像比例尺并实时显示偏差大小来指导调节机床卡盘位置,实现机床两端中心对准。将该算法与几种常用圆检测方法进行比较,在相机分辨率为500万像素时其平均误差为0.047 mm,平均定位时间为244 ms,优于其他检测算法。试验结果表明:该装置对机床对准的精度和效率均有显著提升。在相机分辨率为500万像素时,系统检测误差小于0.1 mm,满足机床同轴检测要求,可为机床同轴调试提供快速有效的方法。

Aiming to solve the shortcomings of alignment time-consuming and low precision in the coaxial debugging of existing optical fiber rod deposition machine tools,a set of automatic positioning and alignment device with high accuracy and high stability was designed and implemented. Firstly,the radial distortion and tangential distortion were eliminated by the Zhang’s calibration method. Then,in order to eliminate the influence of noise and background on the subsequent processing,the images were pre-processed using Gaussian filtering,dynamic threshold and Canny edge detection to extract accurate image edges. Finally,a new arc classification circular detection algorithm was used to achieve the precise positioning of the center of the measured surface in the image. The scale and deviation of the image were determined according to the fitted circle;and the position of the machine tool chuck was adjusted to achieve the center alignment of both ends of the machine tool. When the camera resolution was 500×104,comparing the algorithm in this paper with several common circle detection methods,the average error and average positioning time of our algorithm were 0. 047 mm and 244 ms,respectively,indicating that this algorithm was much better than other detection algorithm. The experimental results showed that the accuracy and efficiency of the device for machine tool alignment were significantly improved. When the camera resolution was 500 × 104,the system detection accuracy was less than0. 1 mm. This work could meet the requirements of machine tool coaxial inspection,and provide a fast and effective method for machine tool coaxial debugging.