Research And Design Of Chromatic Confocal Displacement Sensor

Chromatic confocal displacement sensor is a new kind of photoelectric displacement sensor with super high precision and stability, on behalf of the development direction of advanced displacement sensor, and has been widely applied in the industrial, medical and many other fields. But there is lack of corresponding domestic products and literature currently. The topic starting from the principle of chromatic confocal displacement sensor, designed and built a set of chromatic confocal displacement sensor system based on white LED and optical fiber coupler, meeting certain measurement requirements.In the process of optical system design, analysed the influence of dispersive objective, optical fiber coupler and spectrometer on the system performance, and through the ZEMAX optical simulation software determined the optimal structure of dispersive objective and spectrometer. At the same time, confocal curve under different optical fiber core diameter was calculated according to the imaging quality of the dispersive objective, providing the selection basis for optical fiber coupler.In the process of spectral information processing, analysed the influence of dark level, light source spectrum uneven distribution, random noise and peak wavelength extraction algorithm etc on the spectral peak positioning precision, and through comparing the corresponding data processing algorithms, determined the optimal spectral peak positioning method. Through polynomial fitting algorithm obtained the accurate and stable correspondence between peak wavelength and location.By calibration and measurement of system using dual frequency laser interferometer, results show that system measuring range is 1.2mm, the maximum error is 9μm.