基于四象限探测器的光斑中心高精度定位算法

为了提高四象限探测器检测光斑中心位置的精度,降低现有算法的复杂度,提出了二段式多项式拟合算法。在光斑能量分布服从高斯分布模型的条件下,利用四象限探测器的对称性,简化数据的处理量,将拟合区间合理分为两段进行多项式拟合。同时,针对在拟合区间两端的拟合误差较大的现象进行了优化。仿真分析结果表明,当最高多项式次数为四次时,在原点附近区间,拟合误差仅为10-5mm数量级；在远离原点区间,拟合误差为10-4mm数量级。最后通过实验验证,证明了算法的可行性。

Study on high precision positioning algorithm of spot center based on the four-quadrant detector

In order to improve the detection accuracy of the four-quadrant detector for laser spot center location and simplify the existing algorithm,the two-section polynomial fitting method was proposed.When the spot energy distribution is Gaussian distribution model,the processing of data can be simplified according to the symmetry of the four-quadrant detector.And then the fitting range was divided into two sections for polynomial fitting.Meanwhile,the algorithm was optimized because the fitting error is bigger on the sides of the fitting range.The simulation results show that when the highest degree of polynomial is four,the fitting error is only 10-5mm orders of magnitude in the range near the origin and 10-4mm orders of magnitude in the range away from the origin.At last,the experiment proves the feasibility of the proposed algorithm.