Keywords
Citation
(2005), "Cognex spots the difference", Sensor Review, Vol. 25 No. 1. https://doi.org/10.1108/sr.2005.08725aaf.002
Publisher
:Emerald Group Publishing Limited
Copyright © 2005, Emerald Group Publishing Limited
Cognex spots the difference
Cognex spots the difference
Keywords: Cameras, Automotive industry
When Nissan needed to replace two existing obsolete camera systems with one offering improved capability for precision work, it approached Capley- Marker, a Warrington-based systems integrator specialising in the automotive industry, which proposed the Cognex In- Sight 1000 colour cameras.
The cameras were required to locate the radial force variation (RFV) spots on the tyre and wheel and then transmit the angle between the two spots back to the machine's main control system. The tyre spot would then be rotated to align with the wheel's spot. The key benefit to the spots being aligned is that the RFV is reduced resulting in improved handling of the car (Plate 1).
Plate 1
Cameras are positioned over the assembly line to accurately locate each
tyre and wheel spot
There were many different variations which needed to be located by the vision system; for example, the spots the camera had to detect were of different colours; the wheels could be one of three sizes (14, 15, or 16in. rims); and the tyres could be of any profile. Despite all the different combinations, the In-Sight cameras are able to provide accurate information on each wheel and tyre.
For each camera system a PC was supplied and installed in the new control console which enabled the operator to view real-time inspection results. The camera application was developed so that images of the inspected tyres can be saved as onto the PC and the operator is able to store any or all images for further analysis.
An additional key benefit is that the new camera system was developed around an upgrade to the old, meaning that no modifications were required to the machine's main control system. Information from the cameras continues to be sent to the machine's main control system via its serial port, which is then converted into a 13 bit digital BCD output.