Vision measurement approach of wheelset diameter under re-profiling conditions

Wheelset re-profiling presents an effective maintenance procedure capable of restoring worn railway wheels to compliant operational specifications. The implementation of precise geometric parameter measurement during this re-profiling process could significantly enhance manufacturing efficiency and optimize production costs. Wheelset diameter constitutes a fundamental geometric parameter, the consistency between the diameters of the two wheels is essential for the safe operation of the train and must be accurately monitored during the re-profiling process. Existing diameter measurement systems require sensors to be installed in close proximity to the wheelset, making it impossible to achieve integrated processing and measuring. In this paper, a non-contact measurement approach for wheelset diameter based on binocular structured-light vision is proposed. By designing the wheelset target to calibrate the rotary axis of the re-profiling lathe, the diameter can then be calculated directly, which unifies the measurement benchmark. It is not required to arrange the sensors in close proximity of the lathe, and the wheelset diameter can be obtained on the re-profiling lathe. The simulation and real experiments are validated the feasibility of the measuring approach. The results demonstrate that the root mean square error of wheel diameter measurement is about 0.39 mm, which meets the accuracy requirement of less than 0.50 mm for the re-profiling process.