  Pick-and-place robots are commonly used in modern industrial manufacturing.
For complex devices/parts like camera modules used in smartphones, which
contain optical parts, electrical components and interfacing connectors, the
placement operation may not absolutely accurate, which may cause damage in the
device under test during the mechanical movement to make good contact for
electrical functions inspection. In this paper, we proposed an effective vision
system including hardware and algorithm to enhance the reliability of the
pick-and-place robot for autonomous testing memory of camera modules. With
limited hardware based on camera and raspberry PI and using simplify image
processing algorithm based on histogram information, the vision system can
confirm the presence of the camera modules in feeding tray and the placement
accuracy of the camera module in test socket. Through that, the system can work
with more flexibility and avoid damaging the device under test. The system was
experimentally quantified through testing approximately 2000 camera modules in
a stable light condition. Experimental results demonstrate that the system
achieves accuracy of more than 99.92%. With its simplicity and effectiveness,
the proposed vision system can be considered as a useful solution for using in
pick-and-place systems in industry.
