Research on ultrasonic testing method of rotating component based on a 6-DOF robot

摘要

Abstract Some rotating components have the structural characteristics of variable thickness and variable curvature. The conventional ultrasonic testing is inappropriate for these components because of bad coupling and too many uncertainties. In order to meet the testing requirements of high-volume, high-efficiency and high-precision, the corresponding ultrasonic automatic detection program is proposed. A 6-DOF industrial robot is used to realize the precise control of the transducer position and posture, and combines the independent turntable to complete the spiral fast scan of the specimen. Based on the multi-Gaussian beam model and the internal flat-bottom hole flaw scattering model of specimen, the flaw ultrasonic measurement model is established. The system parameters, component material parameters and component surface parameters are all introduced to the ultrasonic measurement model to generate a series of flaw-sizing curves. An accurate flaw sizing method based on DGS(Distance-Gain-Size)curve predicted by regular reflector is proposed. The scanning experiment results of the reference specimen show that the minimum Ø 0.8mm artificial flat-bottom-hole flaw in the workpiece can be detected effectively, and the sizing error is less than Ø 0.3mm equivalent.