大视场双目视觉传感器的现场标定

Field calibration of stereo vision sensor with large FOV

分析了摄像机和双目视觉传感器的数学模型,针对大视场视觉测量应用,提出了一种基于基线尺的大视场双目视觉传感器标定方法。在测量空间内任意多次摆放基线尺,由两摄像机拍摄基线尺图像。利用基本矩阵及基线尺上两特征点之间距离的约束,采用线性解和非线性优化相结合的方法同时估计摄像机的内部参数以及双目视觉传感器的结构参数。该标定方法操作简单,标定效率高,无需初始参数即可估计双目立体传感器的全部参数。实验结果表明,该方法适合双目立体视觉传感器的现场标定,在6000mm×4500mm的范围内可以得到0.06mm的测量精度。

The mathematical model of a stereo vision sensor is analyzed. Aiming at the application of vision measurement in large Field of View （FOV）, a novel calibration method for stereo vision sensor with large FOV is proposed. A baseline rulur is randomly placed in FOV of the vision sensor for several times and the images of the feature points on the baseline rulur are acquired by the cameras. Then, based on the foundational matrix and the constraint of the known distance between two feature points on the target, the intrinsic parameters of cameras and the structure parameters of stereo vision sensor are simultaneously estimated by the method combining linear solution with nonlinear optimization. The experimental results show that the proposed calibration method is efficient and easy to operate . All parameters of stereo vision sensor can be determined without initial value. By the measurement precision of 0.06 mm in the measurement range of 6 000 mm×4 500 mm,it is proved that the proposed method is suitable for calibrating stereo vision sensor with large FOV on the spot.