Zhu Linlin, Dong Yuchu, Li Zexiao, Zhang Xiaodong
State Key Laboratory of Precision Measuring Technology & Instruments, Centre of MicroNano Manufacturing Technology, Tianjin University, Tianjin 300072, China.
Sensors (Basel). 2020 Sep 13;20(18):5225. doi: 10.3390/s20185225.
The two peaks characteristic of yellow and blue light in the spectrum of dual-wavelength white light emitting diodes (LEDs) introduce distinctive features to the interference signal of white light scanning interferometry (WLSI). The distinctive features are defined as discontinuities, so that the fringe contrast function cannot be modeled as a single Gaussian function, and causes the interferogram to have uneven distribution of fringes of different orders in the scanning interferometer. This phenomenon leads to the low accuracy of the zero-order fringe position in the envelope calculation, which affects the repeatability and accuracy of the interferometry. This paper proposes a new surface recovery algorithm based on the Hilbert phase envelope and adjacent reference points calculation, which can effectively overcome the influence of the discontinuous signal of dual-wavelength LED white light interference on the three-dimensional reconstruction of WLSI measurements. The reliability of the algorithm is verified by experiments, and the measurement accuracy of LED WLSI system is evaluated.
双波长发光二极管（LED）白光光谱中黄色和蓝光的两个特征峰给白光扫描干涉测量法（WLSI）的干涉信号带来了独特特性。这些独特特性被定义为不连续性，使得条纹对比度函数不能被建模为单个高斯函数，并导致干涉图在扫描干涉仪中不同级次条纹分布不均匀。这种现象导致在包络计算中零级条纹位置的精度较低，从而影响干涉测量的重复性和准确性。本文提出了一种基于希尔伯特相位包络和相邻参考点计算的新表面恢复算法，该算法可以有效克服双波长LED白光干涉的不连续信号对WLSI测量三维重建的影响。通过实验验证了该算法的可靠性，并对LED WLSI系统的测量精度进行了评估。
