基于激光扫描的大尺寸圆锥体几何测量系统

Development of a Laser-Based Geometric Measurement System for Large-Scale Conical

针对大尺寸圆锥体工件的几何形貌,提出将三维激光扫描和虚拟环境引导定位结合的快速几何参数测量系统。该系统由两个固定的激光扫描仪高速获取工件两端上表面的关键轮廓,并依据端面特点构造垂直和水平的虚拟基准面,从而生成三维虚拟测量模型;通过高度特征变化识别端面端点位置,结合空间投影和最小二乘原理拟合出端面的圆心位置和直径大小;由空间圆心几何关系计算出锥体高和半角。利用该系统对几种典型的大尺寸圆锥体进行检测,得到端面直径和锥体高的检测分辨力为10μm,检测精度为100μm,锥体半角检测分辨力为0.001°,检测精度为0.010°。实际运行结果表明,该设计系统结合人机交互界面,能很好满足在线生产中对大尺寸锥体工件几何参数检测要求。

According to the characters of large-scale conical workpieces, a novel rapid on-machine geometric measurement system integrating three-dimensional （3D） laser scanning and virtual environments is proposed. In the system, key parts of upper surface of two ends of workpiece are fast captured by two static laser scanners. Vertical and horizontal virtual datum planes are respectively established based on the characters of end planes in order to construct 3D virtual measurement space. The positions of end points are then identified and located by the respect of their height features. Thus, both the center and the diameter of end planes can be obtained by the use of space projection theory and least square method. The height and the taper half-angle can be calculated by the geometric relationship of the center of end planes in 3D measurement space, respectively. The experiments on several typical large-scale conical workpieces are performed. Results indicate that the system can offer the resolution less than 10 μm, measuring precision over 100 μm to the height and the diameter, and it can offer the resolution less than 0.001°, measuring precision over O. 010° to the taper half-angle. According to the actual operation results, this proposed measuring system based on human-computer interaction can be well acceptable for application as on-line geometric detection for large-scale conical workpieces in industrial production.