Wei Zhenzhong, Liu Xiaokun
Opt Express. 2015 Jul 27;23(15):18897-914. doi: 10.1364/OE.23.018897.
Based on analyzing the measurement model of binocular vision sensor, we proposed a new flexible calibration method for binocular vision sensor using a planar target with several parallel lines. It only requires the sensor to observe the planar target at a few (at least two) different orientations. Relying on vanishing feature constraints and spacing constraints of parallel lines, linear method and nonlinear optimization are combined to estimate the structure parameters of binocular vision sensor. Linear method achieves the separation of the rotation matrix and translation vector which reduces the complexity of computation; Nonlinear algorithm ensures the calibration results for the global optimization. Towards the factors that affect the accuracy of the calibration, theoretical analysis and computer simulation are carried out respectively consequence in qualitative analysis and quantitative result. Real data shows that the accuracy of the proposed calibration method is about 0.040mm with the working distance of 800mm and the view field of 300 × 300mm. The comparison with Bougust toolbox and the method based on known length indicates that the proposed calibration method is precise and is efficient and convenient as its simple calculation and easy operation, especially for onsite calibration and self-calibration.
通过分析双目视觉传感器的测量模型，我们提出了一种使用具有多条平行线的平面靶标对双目视觉传感器进行灵活校准的新方法。它只要求传感器在几个（至少两个）不同方向上观察平面靶标。依靠平行线的灭点特征约束和间距约束，将线性方法与非线性优化相结合来估计双目视觉传感器的结构参数。线性方法实现了旋转矩阵和平移向量的分离，降低了计算复杂度；非线性算法确保了校准结果的全局最优。针对影响校准精度的因素，分别进行了理论分析和计算机仿真，得到了定性分析结果和定量结果。实际数据表明，在工作距离为800mm、视场为300×300mm时，所提校准方法的精度约为0.040mm。与Bougust工具箱和基于已知长度的方法进行比较表明，所提校准方法精确，且计算简单、操作方便，高效便捷，尤其适用于现场校准和自校准。
