Call Us +44(0) 1590 679333

Scorpion Vision

INDUSTRIAL CAMERAS AND VISION SYSTEMS

Case Study: Part Marking Inspection - Aerospace


Part Marking Inspection - Aerospace Sector

A multi-national manufacturer of components for the aerospace industry, this company supplies components to the tier one manufacturers. Located in Derby's 'Aerospace Village', this highly successful company is experiencing rapid growth and so needed to implement a level of automation that is not typical within the aerospace industry.

The components produced mainly consist of alloy formed parts - door covers, hatch access panels, etc.

At the end of the manufacturing process, the parts are finished with a top coat of paint and then part marked using an inkjet printer. Every single part is marked with an alphanumeric batch code and prior to the installation of an automated system, this process was carried out by a human at a workbench who's responsibility was to:

 

With a projected growth of component manufacturing increasing 4 fold from several hundred parts a week to several hundred parts a day, it  was imperative that the company deployed an automation system to carry out this work, not least because of the additional workload and human resource required to carry out the work, but also because a high level of quality control was required. An additional benefit of automation is trace-ability by recording of images and data that can be recalled after the event.

 

The solution uses a robot that manages the inkjet and lacquering process. The robot locates the next in-line component from a conveyor belt then presents the component to a camera for part verification. The vision system gives the go ahead and the robot then moves the camera to the printer where the alphanumeric data string is printed onto a predesignated location on the part. The robot system includes a lacquer spray capability and this is then used to seal a rectangular shape covering the area of the print.

 

The last stage of the process calls upon the vision system again to verify the code is readable and that the lacquer has been applied correctly. Detecting the lacquer is perhaps the most challenging aspect of this operation as it does not have colour and is translucent. An optical system was designed that used a multiple light configuration to correctly illuminate the text in one image and get a reflection from the lacquer in another. Using a single Scorpion 2D Stinger camera with in-built LED light source, the lacquer detection image is acquired. The camera is located directly above the region of interest and so when the internal LED is strobed, this generates a strong reflection back from the lacquer. The volume of this reflective area can be measured, ensuring it completely covers the area containing the code. This is the first stage of the pass/fail process. The second stage is of course the code reading. A second image is taken with the same camera, but this time with an external LED light source that is controlled from the 2D Stinger camera, strobed from another angle.This illuminates the code evenly, with no reflection this time, enabling all the characters to be read by the software. The whole process takes less than 3 seconds.

 

   
 Location of printed code Filtered and enhanced text, ready to read  Location and verification of lacquer