Telecentric Imaging-Based Dimensional Measurement for Rotational Components With Magnification and Edge Localization Error Correction

To ensure high accuracy in measuring the diameters of rotational components, this study presents a measurement method based on a telecentric imaging system with magnification and edge localization error correction. A rotational component diameter measurement system is designed, where projection images of the axial cross section of the measured component are captured using an area-scan camera equipped with a bilateral telecentric lens. A calibration method involving both a standard sphere and a pin gauge is proposed to accurately correct magnification and edge localization errors of the system. The diameter measurement results are then obtained by incorporating these error corrections. The effectiveness of the proposed method is demonstrated by measuring two pin gauges with diameters of 12.5 and 7.5 mm, as well as a 20-mm steel ball. Compared to the precalibration results, the measurement error decreased by 0.0350, 0.0424, and 0.0332 mm. In addition, compared with the checkerboard calibration method, the proposed method demonstrated an error reduction of 0.0006, 0.0012, and 0.0024 mm. The proposed method can be extended to telecentric optical imaging measurements for other geometric parameters.