基于无约束系统的结构光三维测量方法

针对传统结构光系统进行三维测量时,要求满足双瞳平行于参考平面和摄像机光轴垂、直于参考平面这两个强约束条件,建立了新的系统结构,去除了平行和垂直的约束,摄像机和投影仪位置可自由摆放.基于该无约束系统结构,提出了一种新的系统标定方法,通过重建"投影仪摄像机参考平面"三者的空间关系,可以简便而精确地获取传统"高度相位"公式中参量:双瞳的距离和摄像机到参考平面距离;同时,推导了无约束系统结构下新的物相关系方程和高度计算公式.实物测量结果证明,基于无约束系统的结构光三维测量方法可操作性强,测量精度可达0.1 mm.

A Structured Light Thre-Dimensional Measurement Method Based on Unconstrained System Configuration

In the most conventional structured light system, the camera must be perpendicular to the reference plane, and the connecting line between the exit pupil of the projecting system and the entrance pupil of the camera must be parallel to reference plane. Aiming at this problem, an unconstrained system configuration is built up, and the parallel and perpendicular constrained conditions are removed. A camera and a fringe projector consisting of the system can be posed freely depending on the objects and the purpose. Based on aforementioned unconstrained system, a new calibration method is presented. In the method, the spatial relationship of “projector-camera-reference plane” can be calibrated and reconstructed accurately, and therefore the important parameters—distance of two pupils and distance from camera to reference plane in the conventional structured light system can be obtained easily. Meanwhile, the new phase-height mapping relationship and height calculating formulas corresponding to the unconstrained system are derived. The experimental results prove that this method can obtain a range data in the accuracy of error about 0.1 mm.