【摘要】 为有效解决高精度视觉定位测量系统中激光随机散斑导致的光斑质心定位精度降低问题，对散斑机理及抑制方法进行研究。从激光光斑的成像过程分析了激光随机散斑出现的原因，并推导出空间中任意一点总波扰表达式。建立了成像介质吸光性、粗糙度和表面出射光信噪比与随机散斑强度的关系模型，得出增加成像介质粗糙度和吸光性来提高出射光信噪比，进而降低随机散斑强度的结论。通过改变成像介质的物理特性进行对比实验，获得光斑质心位置稳定性随成像介质物理特性变化的趋势，验证了关系模型的正确性。实验结果表明，当激光功率为50 mW时，选取吸光性强、粗糙度与厚度适中的成像介质作为成像靶面，激光光斑质心的提取精度稳定在0.04个pixel之内，实现了对激光散斑的抑制，提高了光斑质心的定位精度。更多还原

【Abstract】 To solve the problem of the reduction in the position accuracy of the laser spot centroid caused by laser random speckle in the high-precision visual positioning measurement system, the speckle mechanism and suppression methods were studied. First, the causes of laser random speckle in the laser spot imaging process were analyzed, and the expression for the total wave disturbance at any point in space was derived. Then, a model for the relationships among the light absorption, roughness of the imaging medium, surface outgoing light signal-to-noise ratio, and random speckle intensity was established. It is concluded that increasing the roughness and light absorption of the imaging medium can increase the signal-tonoise ratio of the outgoing light and thus reduce the random speckle intensity. Finally, comparison experiments were performed to obtain the trend chart of the stability of the spot centroid position with changes in the physical characteristics of the imaging medium, and the results validated the relationship model. The experimental results indicate that when the laser power is 50 mW, the imaging medium had strong light absorption, and the imaging target surface had moderate roughness and thickness, the stability of laser spot centroid extraction is within 0.04 pixels. Laser speckle is suppressed, the stability of imaging spot coordinate extraction is improved, and the accuracy of spot centroid positioning is increased.更多还原