Detection of defects in the manufacturing of electric motor stators using vision systems: Electrical connectors

There are many applications which make use of electric motors. These machines are mainly composed of a rotor, which is the rotating part, and a stator, the fixed part which creates the magnet field that rotates the rotor. Regarding induction motors, the stator manufacturing process is much more complex than the rotor one, so its rate of defects is also higher. In order to control these events, inspections are commonly done by human operators, which are subjected to fatigue and lack of attention. This paper presents the development of an automatic vision system to inspect defects of electric motor parts in assembly lines, specifically the force-induced disconnection of the stator power cables inside the electrical connector. A test rig and software routines for implementing the proposed inspection principles have been developed. A case study using 20 connectors of real motors was proposed for evaluating the vision system and the results showed that it was able to correctly identify 100% of the defects.