液压元件的外形尺寸是否合格直接关系到液压产品的质量及性能。针对液压元件表面弱纹理对测量造成较大干扰的问题,采用向目标场景投射随机斑点的方法来增强液压元件的纹理。组建了双目立体视觉系统,运用新型圆阵列标定板对其进行标定,获取了双目相机的内外参数。针对双目相机采集的数字图像,使用归一化协方差相关算法在极限约束后进行像素匹配,得到视差值,进而得到液压元件相应位置的三维数据。实验结果表明:该系统能够得到较为清晰的点云图,对于液压元件的测量具有较高的识别率和较好的鲁棒性,可以满足弱纹理液压元件在流水线生产中的实时检测。

Whether the external dimensions of hydraulic components are qualified is directly related to the quality and performance of hydraulic products. Aiming at the problem that the weak texture on the surface of the hydraulic component caused great interference to the measurement, the method of projecting random spots to the target scene was used to enhance the texture of the hydraulic component. A binocular stereo vision system was set up and calibrated by a new circular array calibration plate to obtain the internal and external parameters of the two cameras. The digital images collected by binocular cameras were matched by pixels using the normalized covariance correlation algorithm after the limit constraint to obtain the disparity value and the three-dimensional data of the corresponding positions of the hydraulic components. Results showed that the system can obtain clearer point cloud images, and has a higher recognition rate and better robustness for the measurement of hydraulic components. It can meet the real-time detection of weak texture hydraulic components in assembly line production.