Accuracy improvement of laser triangulation sensor via orthogonal experimental design

Abstract Laser triangulation measurement system (LTMS) based on the Scheimpflug principle has widespread applications in the field of 3D reconstruction, yet its systematic error and correction methods fail to adequately studied. To reduce the systematic error of the LTMS, the paper establishes a measurement model and a systematic error model based on the Scheimpflug principle for the LTMS, and derives the distribution function of the systematic error caused by inaccurate actual structural parameters. Moreover, the detection indicator for systematic error is confirmed to be nonlinearity. Then, the orthogonal experimental method is introduced to minimize systematic error. According to the distribution characteristics of systematic error, nine experimental control groups are selected for parameter quantification to identify the primary and secondary factors and find the optimal level combination. The experiment results indicate that the introduction of orthogonal experimental method can reduce the nonlinearity of the sensor at least by 60%. And the method effectively reduces systematic error in LTMS in term of the optimal level combination.