针对远距离大尺寸物体三维形貌测量的要求,设计并实现了基于激光三角法原理的双振镜点扫描三维形貌测量系统。介绍了系统的结构和测量原理,并对系统进行建模,推导了被测物体表面测量点的三维坐标计算公式。构建了原型系统,利用专用的二维平面靶标在测量空间内自由摆放数次,根据靶标上特征点及其像点间的位置关系,以坐标系转换为基础实现了测量系统结构参数的现场标定。利用李萨如图扫描模式分别对靶标平面、已知直径的球面及石膏像自由曲面进行了测量实验。结果表明,测量距离1m处,测量点到拟合平面的距离误差均值为0.70mm,球面直径测量误差均值为0.51mm;测量距离10m处,测量点到拟合平面的距离误差均值为17.85mm。该系统可用于远距离大尺寸物体表面的三维形貌测量。
In order to measure the three-dimensional shape of a large scale object in a long distance,a three-dimensional shape measurement system based on dual oscillating mirror scanning was designed and implemented.Firstly,the principle and the configuration of the system were presented and the system model was derived.Secondly,the field calibration of the structure parameters of the system was accomplished based on the coordinate transformation by taking pictures of a special planar board from different directions.Finally,the plane board,sphere and curved plaster figures were measured and reconstructed by using Lissajous scanning pattern.The measurement results show that the average errors of the distance between the measuring points and the fitted plane are 0.70 mm and 17.85 mm at the distance of 1 m and 10 m,and the average error of the fitted sphere diameter is 0.51 mm at the distance of 1 m.The system can be used for the three-dimensional shape measurement for large scale objects in the long distance.