Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
Sensors (Basel). 2023 Jan 28;23(3):1453. doi: 10.3390/s23031453.
A new sensor type is proposed to accurately detect the surface profiles of three-dimensional (3D) free-form surfaces. This sensor is based on the single-exposure, zero-crossing method and is used to measure position and angle simultaneously. First, the field intensity distribution in the posterior focal plane of the confocal microscope's objective was modeled accurately. Second, because the camera needs to trigger acquisition when the surface (to be measured) reaches the focal position of the sensor, a zero-crossing prediction method based on a sliding window was proposed. Third, a fast, spatially convergent, peak-extraction algorithm was proposed to improve the accuracy and efficiency of peak extraction. This scheme reduces system installation and adjustment difficulties, and the single-exposure, zero-crossing method achieves high-speed, real-time image acquisitions. The experimental results indicate that the average error of the zero-crossing prediction system was 17.63 nm, the average error of the tilt degree measurement was 0.011° in the range of 0-8°, and the prediction error of the tilt direction measurement was 0.089° in the range of 0-360°. The sensor can measure the slope and can be potentially used for 3D surface precision detection.
提出了一种新的传感器类型，用于准确检测三维（3D）自由曲面的表面轮廓。该传感器基于单次曝光、过零方法，可同时测量位置和角度。首先，准确地对共焦显微镜物镜后焦面的场强分布进行建模。其次，由于相机需要在表面（待测量）到达传感器的焦位置时触发采集，因此提出了一种基于滑动窗口的过零预测方法。第三，提出了一种快速、空间收敛的峰值提取算法，以提高峰值提取的精度和效率。该方案降低了系统安装和调整的难度，单次曝光、过零方法实现了高速、实时的图像采集。实验结果表明，过零预测系统的平均误差为 17.63nm，在 0-8°范围内倾斜度测量的平均误差为 0.011°，在 0-360°范围内倾斜方向测量的预测误差为 0.089°。该传感器可以测量斜率，可潜在用于 3D 表面精密检测。
