基于双目多线结构光的铆钉齐平度测量方法

Rivet Flatness Measurement Method Based on Binocular Multi-Line Structured Light

对于铆钉齐平度的测量,使用传统检具或非接触式点云扫描的测量方法分别存在局限较大、准备周期长、数据难处理等缺点。针对上述问题,提出一种基于双目多线结构光的铆钉齐平度测量方法,首先对双目系统采集到的结构光图像进行双目匹配与重建,提取、拟合出在测量坐标系下铆钉头圆轮廓内离散像素点的坐标与局部蒙皮平面的表达式,随后引入离散点筛选比例系数进一步优化局部蒙皮平面的拟合精度,将其代入铆钉齐平度测量模型中进行计算获得结果。相比于传统接触式测量与点云扫描,此研究方法节省了处理点云数据所需的大量时间,提高了测量效率,通过机械臂搭载小型测量末端能够完成对飞机进气道等狭窄内腔的检测任务,降低了局限性。试验结果表明,该方法对于铆钉头凹凸两种特征均适用,且齐平度的最大测量误差小于0.03mm,满足视觉测量要求。

As for rivet flatness measuring,the measurement methods using traditional gage measurement or noncontact point cloud scanning have disadvantages such as large limitations,long preparation periods and difficult data processing.In response to the above problems,this paper proposes a method for measuring the flatness of rivets based on binocular multi-line structured light.Firstly,binocular matching and reconstruction are performed on the structured light image collected by the binocular system,and the measured coordinate system is extracted and fitted.Next,discrete point screening proportional coefficient is introduced to optimize the fitting accuracy of local skin plane and then the discrete point screening scale factor is introduced to further optimize the fitting accuracy of the local skin plane,and finally it is substituted into the rivet flatness measurement model to perform calculations to obtain results.Compared with the traditional contact measurement and point cloud scanning,this method saves a lot of time for point cloud data processing and improves the measurement efficiency,and can complete the detection task of narrow cavity such as the aircraft inlet by mechanical arm equipped with a small measurement terminal,which reduces limitations.The experimental results show that this method is applicable to both concave and convex features of the rivet head,and the maximum measurement error of rivet flatness is less than 0.03mm,which meets the requirements of visual measurement of rivet flatness.