Wavelength scanning-based spectral confocal displacement measurement method and device

Abstract

The invention belongs to the field of photoelectric measurement, aims to realize precision measurement of a non-contact displacement and achieve high measurement precision and quick and easy operation. A wavelength scanning-based spectral confocal displacement measurement device comprises the following components: a wavelength scanning light source, an input optical fiber, an optical fiber coupler, a pin hole, a dispersion objective lens, an output optical fiber and a photoelectric detector; the wavelength scanning light source outputs single-color light; a wavelength is scanned back and forthwithin upper and lower limit wavelength ranges; the single-color light emitted by the light source is coupled with the input optical fiber; the input optical fiber is connected into the optical fibercoupler; the optical fiber coupler outputs the light to the pin hole to form a point light source; the single-color light is gathered to a certain focal point on an optical axis through the dispersion objective lens; in the wavelength scanning process, the single-color lights with different wavelengths can form a series of focal points; at a specific moment, the focal point of a certain single-color light is just superposed with a surface to be measured; and reflected light at the focal point is converted into a voltage signal through the photoelectric detector. The wavelength scanning-basedspectral confocal displacement measurement device is mainly applied to a photoelectric measurement occasions.

Description

technical field [0001] The invention belongs to the field of photoelectric measurement, in particular to a spectral confocal displacement measurement method and device based on wavelength scanning. Background technique [0002] With the development of advanced manufacturing industry, the demand for precision displacement measurement is increasing day by day. Displacement measurement technology is often used in the detection process of vibration, shape, thickness and other geometric quantities. It not only needs to have high precision, but also needs to be able to adapt to different environments and materials, and gradually tends to real-time and non-destructive testing. Displacement measurement can be divided into contact measurement and non-contact measurement. Although contact displacement measurement can have high measurement accuracy, it has many limitations, such as causing damage to the surface of the measured object; it is not suitable for measuring objects with fine ...

AI Technical Summary

Problems solved by technology

However, this conventional spectral confocal technology still has defects. First, due to the limited power of the broadband white light source (usually only tens of mW), the average value of each wavelength is smaller, resulting in a very low signal-to-noise ratio of the received signal; Second, because the measurement system must use a spectrometer to split the light, and the spectrometer generally uses a grating to split the light and an array CCD sensor to receive it, and its measurement speed is slow, resulting in a decrease in the system response speed

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