Development of an Automated Line-Laser System for Non-Contact Measurement of Bevel Gears

This paper presents an automated, non-contact optical method for measuring bevel gears, using a line-laser triangulation sensor mounted on a five-axis CNC machine. In the proposed configuration, the table-tilting axis adjusts the laser beam's incident angle, while the other four axes move the sensor to scan the entire tooth surface. The automated measurement system is designed to synchronize real-time data collection from the laser sensor and the machine controller, allowing for accurate reconstruction of the gear's tooth surface geometry. First, a comprehensive mathematical model must be established to describe the spatial transformations between the laser sensor and gear coordinate systems. The measurement algorithm involves profile denoising, convex–concave segmentation, polynomial curve fitting, and triangulated surface reconstruction for both pitch and flank evaluations. An experimental measurement of a bevel gear was conducted using a blue-laser sensor, and the reconstructed tooth surfaces were compared with those obtained from a Klingelnberg P40 measuring machine. The results show that the measurement deviations were less than 25 μm, demonstrating strong agreement with the commercial measuring results. These experimental results verify the accuracy, reliability, and applicability of the proposed method for advanced bevel-gear manufacturing and inspection.