关键词: 仪器仪表技术, 机器视觉检测, 图像处理, 测量, 滚珠螺母, 误差

Abstract: On the basis of machine vision, a the noncontact detection method was put forward to measure the geometrical size and shapeposition error of the ball nut. The image was collected by a digital camera A102FCCD, and was input into computer by a digital interface card IEEE1394. The original gray level image was changed into the macroscopical drawing information by preprocessing, threshold selection, image bivalency, edge detection and contour extraction and segmentation. The geometrical parameters were calculated and measured by the aid of the contour extracted from the image processing and a selfcompiled measurement program. The ball nut thread pitch, radius of the ball center circle, the sphericity deviation, the cylindricity deviation, and ballway taper were measured and their errors were 0.001, 0.023, 0.010, 0.016 and 0.006 mm respectively. The reason for error was analyzed, and concluded that the optic error is the main factor affecting the measurement precision. The results satisfy the technique requirement of the product. Theoretical analysis and experimental results show that this method is feasible and correct.

Key words: technology of instrument and meter, machine vision detection, image processing, measurement, ball nut, error