Optimized temperature measurement method based on single-camera colorimetric temperature measurement system

Abstract

The invention discloses an optimized temperature measurement method based on a single-camera colorimetric temperature measurement system, and relates to calibration of spectral intensity proportion distribution, optimization of a pixel unit temperature calculation formula and calibratio and optimization of pixel unit temperature calculation formula parameters, wherein calibration of the spectral intensity proportion distribution comprises optical filter selection, single-camera colorimetric temperature measurement system position fixation, first waveband image and second waveband position calibration and sub-image matching, first waveband and second waveband dual-channel image collection, reference target point spectral intensity proportion calculation and to-be-measured area spectral intensity proportion distribution calculation; optimization of the pixel unit temperature calculation formula comprises substituting the obtained reference target point spectral intensity proportion as anoptimization parameter into the temperature calculation formula of the temperature measurement system; calibration and optimization of the parameters of the pixel unit temperature calculation formulacomprises optical filter selection, reference temperature point selection, blackbody furnace temperature rise, image collection, calibration formula derivation and multi-parameter collaborative optimization. And the measured temperature is more accurate by optimizing the temperature measurement method.

Description

technical field [0001] The invention relates to the technical field of infrared pyrometry, and more specifically, to an optimized temperature measurement method based on a single-camera colorimetric temperature measurement system. Background technique [0002] In the process of metal additive manufacturing, the temperature of the molten pool formed after the melting of metal powder is usually above 1000°C, and the quality of the molded parts is closely related to the temperature distribution of the molten pool. In recent years, researchers usually measure the molten pool temperature field. Online monitoring of printing quality; during the high-speed operation of the aero-engine turbine, the local temperature on the surface of the aero-engine turbine blade is as high as 1600°C. Accurate measurement of the surface temperature can provide an important reference for evaluating the performance of the aero-engine and improving the structural design. [0003] At present, in the fie...

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Problems solved by technology

[0005] At present, some scholars have used the black body furnace calibration method to determine the coefficient K of the colorimetric temperature measurement system, such as the Chinese patent with the patent number ZL201810769907.2, and "Research on a New Infrared Temperature Measurement Method" (Li Xiang et al., Tianjin University of Science and Technology, 2010), the above-mentioned literature provides a method for calibrating the coefficient K to avoid the problem of "emissivity measurement difficulty", which improves the measurement accuracy of the colorimetric temperature measurement system to a certain extent, but the method provided only calibrates the Coefficient K, while ignoring K, λ 1 ’ and λ 2 ’ The correlation of the three system parameters, λ 1 ’ and λ 2 ’Improper selection will bring non-negligible errors to the temperature measurement results

[0006] In addition, although many scholars currently study the selection of dual-band in the dual-band colorimetric temperature measurement method, how to determine the wavelength parameter λ in the colorimetric temperature measurement formula when calculating the temperature after the dual-band is determined 1 ’ and λ 2 ’ There is no precedent for relevant research on the specific value

For example, the literature "Selection of Dual Wavelengths for Colorimetric Temperature Measurement and Calculation of the Minimum Bandwidth of Filters" (Wu Haibin et al., Anhui University, 2006) and the literature "Wavelength Selection for Colorimetric Temperature Measurement" (Feng Chi, Harbin Engineering University, 2013) , the above literatures all discuss the selection method of dual bands in the colorimetric temperature measurement method. Light is a band rather than a single wavelength, but the parameter λ in the colorimetric temperature measurement formula 1 ’ and λ 2 ’ are all single-wavelength, and most scholars generally regard the central wavelength of the filter’s working band as the parameter λ 1 ’ and λ 2 'Calculations, such as "Real-time Detection of Laser Melt Pool Temperature Field Using Image Colorimetry" (Jiang Shujuan et al., Key Laboratory of Advanced Manufacturing Technology, Shenyang Institute of Automation, Chinese Academy of Sciences, 2008) Such selection is likely to cause large errors, Therefore, it is necessary to further solve the selection problem of these two parameters within the working band range of the filter. No scholars have found relevant research on this problem.

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