数控玻璃雕刻机上Mark点视觉定位系统的设计与实现

Design and Realization of the Mark Point Visual Positioning System on the CNC Glass Carving Machine

针对手机电容屏生产工艺,即先丝印后根据其中的Mark点来定位再加工外形,在原有数控玻璃雕刻机的基础上设计了Mark点视觉定位系统。提供了视觉定位与CNC运动控制结合的方案,使用视觉定位来设置CNC加工的工件零点和路径偏转角。视觉定位算法上,采用模板匹配来识别Mark和粗定位,用霍夫变换来分类Mark的边缘点集,再用最小二乘法精确拟合边缘方程,进而计算得到最终的Mark点位置。该定位系统已应用于实际生产中,时间和精度都基本满足生产工艺要求。

A mark point visual positioning system is designed on the common CNC carving machine, which is used to produce the capacitive touch screen in cell phone. In the production process, it is needed to carve the profile in accordance with of the silk-screen on the glass by recognizing marks and figuring out their position. The method which is combining visual positioning and CNC motion control is provided. The visual positioning system is used to set the workpiece zero and the deflection angle of CNC machining path. In visual algorithm, template matching is used to recognize the mark and get its rough position, Hough transform to sort the edge points of Mark, then to precisely the equation of edge lines, with the least squares method to calculate the ultimate Mark point position. The system has been applied in practical production, and results show that it meets the time and accuracy requirements of production technology. [ Ch, 11 fig. 10 ref. ]