基于虚拟圆柱的曲面拼接方法

Novel Connection Method Based on Virtual Cylinder for Three-Dimensional Surface Measurement

圆柱坐标下的多视角 (孔径 )扫描拼接方法主要针对类似回转物体面形的拼接测量 ,用该方法在对非单一回转轴 ,或者近似回转轴位置远离坐标轴形式的一类物体面形的拼接测量时遇到了困难 ,把拼接方法推广到基于虚拟圆柱可以解决这一难题。为此提出了基于虚拟圆柱原理的曲面拼接方法 ,给出了如何估计虚拟圆柱的半径 ,以及轴心坐标的计算方法 ,推导了基于虚拟圆柱的坐标转换方程 ,通过计算机模拟验证了其精确性 。

The multi view (i.e. multi aperture) overlapping scanning connection technique in cylindrical coordinates is mainly used in connecting measured surface of quasi rotating objects. It comes into difficulty in surface measurement of object with non single revolving axis, or whose quasi revolving axis is comparatively far from the coordinates axis. A novel connection method is presented on the basis of the principle of the virtual cylinders to solve this problem. This extended connection method on the basis of the virtual cylinders for three dimensional shape measurement is described, the algorithms how to calculate the approximative radius of the virtual cylinders and the coordinates of its revolving axis are given, and the coordinates translation formula is deduced based on the virtual cylinders. The accuracy of this method has been theoretically verified by computer simulation. And the experimental measurement result of an automobile headlamp reflector reassures experimentally that the method is effective and feasible for three dimensional complex shape connection, especially to obtain the connected surface tested from different views.