为了对水下物体进行高速度、大范围的三维测量,提出了水下线结构光自扫描三维测量技术。采用振镜将激光面反射到被测空间,激光面与被测物体相交形成光条并被摄像机拍摄,根据像面上光条中每一点的位置计算出该点由于折射产生的偏移大小并加以补偿。再利用考虑折射后的光平面水中部分在振镜坐标系下的方程,求出物体表面的三维坐标。实验结果表明,所提出的水下自扫描系统模型及水下三维测量方法可行,在深度为0.5-1 m,测量高度为0.5 m,测量宽度为0.6 m的空间内测量精度达到0.7 mm。

In order to achieve three-dimension high-speed and large-scale measurement to underwater objects,an underwater line structured-light self-scan three-dimension measuring technology is presented. A galvanometer is adopted to reflect laser plane onto object′s surface. The laser plane intersects the surface of object and a light stripe which is photographed by a camera is formed. According to the position of each point of light stripe on image,the offset caused by refraction is calculated and compensated. Then utilizing the equation of laser plane in water,accurate 3D coordinates of detected points are accurately calculated out. Experimental results show that the model of underwater self-scan system and underwater three-dimension measurement method are feasible. The measurement precision in the space of depth of 0.5-1 m,measuring height of 0.5 m and measuring width of 0.6 m achieves 0.7 mm.