Analysis of line laser measurement error caused by nonlinear light refraction under the high-temperature environment

Abstract

For optical measurement of high-temperature components, it is a challenge to analyze the measurement error caused by light refraction due to the inhomogeneous distribution of the air refractive index. Aiming at the problem of line laser measurement under the high-temperature environment, a method for analysis of line laser measurement error on high-temperature surfaces combined with backward ray tracing technology is proposed. The temperature field of the air is simulated based on the heat conduction theory, and the air refractive index is obtained according to the classical empirical formula. Combining with the refraction law of light and the laser triangulation method, the deviation of the spatial position corresponding to each point on the charged-coupled device is calculated. The imaging principle of backward ray tracing is applied to obtain the actual imaging point, and the measurement error of the sensor is calculated. The experiment results prove that the proposed method can effectively evaluate the line laser measurement error under the high-temperature environment. We analyze the system error of the laser sensor under high-temperature conditions and promote the development of high-temperature components on-machine measurement.