在诸多需要对光斑质心进行定位的领域里, 光斑质心定位的精确性和稳定性都是至关重要的。根据光学系统对物体边缘的模糊原理, 提出一种新的光斑中心提取算法。该算法是以反正切函数为基函数, 通过对其变量代换从而得到可以拟合光斑灰度分布的函数。求解过程中首先通过高斯-牛顿法进行迭代, 然后再通过最小二乘法进行最优解估计。文中先通过仿真分析, 对比了文中算法与传统算法的优劣, 进一步通过实验验证该方法相对于传统方法的优势。实验结果表明: 基于文中算法光斑质心提取精度为0.125 3个像素; 此时角度传感器的测角精度为0.172 3″, 优于传感器技术要求的0.25″。文中算法对噪声、对比度、光斑的长宽比和大小的综合性能优于传统算法, 实验结果稳定可靠, 满足角度传感器使用要求。

The precision and stability of spot centroid location were crucial in many fields. According to the edge blurring principle on the optical system, a new algorithm of spot centroid extraction was proposed. The proposed algorithm, based on the arctangent function, can be used to fit the gray distribution of the light spot by variable substitution, and then the centroid of spot can be obtained. In the process of solution, the Gauss-Newton method was adopted to iterate, and then the least square method was used for optimal estimation. Firstly, the advantage and disadvantages of the proposed algorithm between the traditional algorithms were obvious through comparison analysis, and then the feasibility was validated experimentally. The experimental results show that the location precision of the spot centroid is 0.125 3 pixels, and the angle measurement accuracy of the photoelectric sensor is 0.172 3″, superior to the sensor′s technical requirement 0.25″. The robustness of the proposed algorithm to noise, contrast, aspect ratio and size is superior to the traditional algorithms. The experimental results were stable and reliable, and meet the requirement of the angle sensor.grayscale fitting