Absolute angle measurement using dual-wavelength laser speckle: Theory and method
Absolute angle measurement using dual-wavelength laser speckle: Theory and method
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DOI：
10.1016/j.optlaseng.2023.107956
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发表时间：
2024-03
影响因子：
4.6
通讯作者：
Sam J. Gibson;T. Charrett;R. Tatam
中科院分区：
文献类型：
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作者：
Sam J. Gibson;T. Charrett;R. Tatam
本文提出了一种利用双波长照明形成的散斑图样测量相对于传感器框架的两个离面面角的方法。推导了由两个波长形成的倾斜表面在轴上和离轴探测器位置上形成的图案之间的观察到的散斑位移的理论表达式。这些公式得到了实验验证，均方根误差在0.5-1.0图像1之间。最后，利用标准FP半导体激光器的两个模式产生的双波长照明，给出了该概念的轴上实现。给出了利用这种布置从测量的散斑位移计算表面角度的简化表达式，给出了三个传感器常数：传感器的响应度或灵敏度C，以及零表面倾斜散斑移位Ax0和Ay0。使用该传感器对图像2和图像3之间的表面倾斜范围进行的实验结果显示，图像4在θx中的均方根误差和图像5在θy中的均方根误差。
This paper presents a method utilising the speckle pattern formed by dual-wavelength illumination for the measurement of the two out-of-plane surface angles with respect to the sensor frame. Theoretical expressions are derived relating the observed speckle shift between patterns formed by two wavelengths for tilted surfaces with both on-axis and off-axis detector positions. These expressions are verified experimentally, showing RMS errors of between 0.5–1.0 Image 1. Finally, an on-axis implementation of the concept is presented using dual-wavelength illumination generated from two modes of a standard FP diode laser. Simplified expressions for the calculation of surface angles from measured speckle shift using this arrangement are presented, given in terms of three sensor constants; the responsivity or sensitivity of the sensor, C, and the zero surface tilt speckle shifts, A x 0 and A y 0. Experimental results using this sensor for a range of surface tilts between Image 2 and Image 3 showed an RMS error of Image 4 in θ x and Image 5 in θ y.