机械视觉疲劳裂纹扩展试件自动定位安装方法

The installation and position method of fatigue crack propagation specimen Based on Machine Vision Technology

摘要:

针对现有疲劳裂纹扩展试验中试件的安装定位仍采用操作繁琐、效率低下的手动安装问题,本文提出了一种基于机械视觉的疲劳裂纹扩展试件安装定位方法,首先,对试件及夹具图像进行采集、处理和分析,实现夹具、试件圆心坐标及半径的自动快速识别、孔差距离的精确测量；然后利用模糊PID算法来控制直流伺服电机运动定位,从而实现试件的正确安装定位；最后采用工业数字显微镜对不同时间点的试件位置偏差进行停机测量对比,实验结果表明：所提出方法能够对试件进行精确安装定位,最大偏差为0.122 mm,具有重要的理论和应用价值,并为其它类似基于机器视觉的检测定位方法提供了有价值的参考。

Abstract:

Aiming at the work tedious repetitive and low efficiency in the installation and position of specimen during the high frequency fatigue crack test, the installation and position method of fatigue crack propagation specimen was proposed, which can recognize the center coordinates and radius of fixture and specimen automatically and quickly, measure the holes distance accurately. then the fuzzy PID was used to control the DC servo motor. In order to validate the accuracy of the fatigue crack propagation specimen installation and position system, the digital microscope was used to measure the specimen position deviation at different time points. The research results show that the proposed method can measure the holes distance between fixture and specimen accurately, the maximum deviation is 0.122mm. All above, the presented method is valid and accurate, which provides a valuable reference for other detecting and positioning systems based on machine vision., and it has theoretical significance and practical value.