Zhou Yingjian, Yuan Yanhong, Su Meixue
School of Mechanical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Zhejiang Light Industrial Products Inspection and Research Institute, Hangzhou 310018, China.
Sensors (Basel). 2024 Mar 13;24(6):1838. doi: 10.3390/s24061838.
In this paper, a system for absolute distance measurement is proposed based on laser frequency scanning interferometry (FSI). The system utilizes a digitally tunable laser as the light source and employs synchronized pulses to drive an analog-to-digital converter (ADC) for interference signal acquisition. The frequency domain demodulation for absolute distance measurement is achieved through a three-spectrum line interpolation method based on the Hanning window. The system takes advantage of the spatial filtering characteristics of a single-mode optical fiber and the diffuse reflection properties of light to achieve a high integration of the prism system that forms the interference optical path. The resulting integrated fiber-optic probe is capable of measuring the distance to a non-cooperative target even when oriented at a certain angle with the target. We designed and fabricated a portable prototype. Experimental validation demonstrated that the maximum measurement distance of the system is 73.51 mm with a standard deviation of less than 0.19 μm for optimal measurement results. Even when there is an offset angle, the system maintains good measurement repeatability.
本文提出了一种基于激光频率扫描干涉测量法（FSI）的绝对距离测量系统。该系统采用数字可调谐激光器作为光源，并利用同步脉冲驱动模数转换器（ADC）采集干涉信号。通过基于汉宁窗的三谱线插值法实现绝对距离测量的频域解调。该系统利用单模光纤的空间滤波特性和光的漫反射特性，实现了构成干涉光路的棱镜系统的高度集成。由此产生的集成光纤探头即使在与目标成一定角度时也能够测量到非合作目标的距离。我们设计并制作了一个便携式原型。实验验证表明，该系统的最大测量距离为73.51毫米，在最佳测量结果下标准偏差小于0.19微米。即使存在偏置角，该系统仍保持良好的测量重复性。
