A thermographic visual inspection system for crack detection in metal parts exploiting a robotic workcell

Stefano Ghidoni, Mauro Antonello, Loris Nanni, Emanuele Menegatti
2015 Robotics and Autonomous Systems  
h i g h l i g h t s • Thermography was explored as a means for the detection of micro defects. • We developed a system capable of finding cracks in metal parts using thermography. • The system is very robust thanks to the complete knowledge of the imaging process. • The system is able to deal with parts of very complex geometry. • The proposed inspection method is cleaner than other alternatives currently in use, and does not use polluting substances. a b s t r a c t Cracks are the main source
more » ... f failure in the production of metal parts: systems for checking their presence are therefore crucial for defect-free production. In this paper, an autonomous system for performing this quality control is presented. The system is equipped with a heating tool, a thermocamera, and a robot to handle the part. The inspection process is based on the observation of the propagation of thermal waves through the inspected part, a method that can highlight very small cracks with high reliability. A knowledge-based approach to visual inspection is exploited for detecting the cracks: all the system parameters are known by means of an accurate calibration of the workcell. The system was tested on a large dataset and demonstrated its capability of detecting tiny production defects, that can lead to dangerous failures when the metal components are put under strong mechanical stress.
doi:10.1016/j.robot.2015.07.020 fatcat:qxrj5gnzjjcglh3dtkg53kr3ga