Robotic Vision Inspection Solution from Aylesbury Automation Limited

The process, for which AA Robotics has provided the technical solution, involves the inspection of compartments in packaging boxes. The boxes are used to transport vials, containing liquid drugs, between production and packing. Once the vials have been removed from the compartments the boxes are returned to the production process for refilling. Ensuring that the box compartments are empty requires a visual check. This visual check is now conducted by an automated robotic process.

The boxes pass beneath a Cognex Insight camera mounted on the Z axis of an inverted DENSO Scara robot arm. Each robot moves the camera around the compartments of the box, checking that all the vials have been removed. The inspection cycles take 20 seconds which is a significant improvement on the previous system rate. A major benefit of the inverted DENSO SCARA arm was that it was able to operate successfully in the tight confines of the existing production line.

Ethernet communication operates between the robots and cameras. The boxes are only released for the following process when they are authorised to do so by the system. Message protocol ensures that each message to release a box is unique and contains new data. Each cycle of inspection is self-checked as the Cognex Insight camera records its position at the start and end of the cycle in order to verify that the images seen are correct.

The DENSO robots position the cameras to a tolerance of 0.015 mm and provide a stable camera platform which enables discernable vision images of the corners of the boxes to be repeatably produced – something not possible with the use of a fixed camera system. Only one set of parameters and lights are required to enable the complete inspection process. When inspections are not taking place the camera is moved out of the area, thereby minimising the danger of disturbing the camera or its associated lighting.