基于最优投影平面的立体视觉空间圆位姿高精度测量方法

现有基于双目立体视觉的测量方法的测量精度依赖于标定精度,在受遮挡时测量精度不高.文中首先分析并证明在双目立体视觉系统外部参数误差存在时,投影曲线上点的立体匹配误差对点的重建精度的影响.然后基于此误差分析结论,设计立体视觉空间圆位姿测量方法,通过轮廓点筛选算法筛选投影曲线上的点,得到匹配误差较小的点并进行重建.利用重建点在深度方向上对非线性优化得到最优投影平面的投影,对空间圆进行拟合,得到空间圆的位置姿态.文中方法有效减小三维点重建误差对空间圆拟合精度的影响,提高圆形特征在受遮挡情况下的测量精度.最后通过实验验证方法的有效性.

An Optimal Projection Plane-Based Spatial Circle Measurement Method Using Stereo Vision System

The accuracy of the existing measurement method based on binocular stereo vision depends on the accuracy of calibration, and the accuracy of measurement decreases when the spatial circle is occluded. Firstly, the reconstruction accuracy of point affected by the stereo matching error of points on projection curves is analyzed in the presence of external parameter error of the binocular stereo vision system. Then, based on the conclusion of error analysis, a new method for measuring the position and orientation of spatial circle is designed. Using the edge points selecting algorithm, the points of projection curves are selected. The circle is then reconstructed using the points with small stereo matching error. The projection of the reconstructive points on the optimal projection plane based on nonlinear optimization in the direction depth is utilized for fitting spatial circle to obtain the position and orientation. Experimental results prove the effectiveness of the proposed algorithm.