Sistema is one of the fastest growing food storage brands in the world. The distinctive plastic clips on Sistema’s plastic products are well-known in households across New Zealand, and increasingly around the world. Although the clips had traditionally been attached on the base of a container, when Sistema introduced a new range which featured smaller clips attached to the lid, issues in the manual production process led to the search for an automated solution to lower costs and increase efficiency.
Workers were finding it physically challenging to apply the clips to the lids, and as the clipping process was run offline – the lids were moulded and sealed separately, before being collected to have the clips applied – one automation solution would work for multiple product lines.
Having already worked with Sistema to successfully install a camera-guided robotic labelling system, Basler partner ControlVision was tasked with providing a solution to enable the automation of the clipping process.
A major challenge of the project was ensuring precise accuracy for the clip placement while maintaining a high speed on a moving conveyor, as there was an overall tolerance of less than 0.5 mm for the clip to be successfully applied. It was also vital that the system could handle a wide range of lid sizes and shapes, as well as different clip colors.
In order to obtain the high quality images required to meet the stringent tolerance requirements for the solution, ControlVision chose four Basler scout cameras to obtain images of both the clips and the lids.
In the system, two conveyor belts carry the lids and clips separately in parallel. Encoder feedback is employed to enable the accurate tracking of the clips and lids on the moving conveyors.
Upstream of the robots, a Basler scout scA640-74gm GigE camera captures an image of the clip, which is sent to the VisionServer software to determine its position. Once the position is determined, VisionServer guides one of the Dual Adept Cobra s600 robots into picking up the clip.
A separate, higher resolution camera, a Basler 2 MP scout scA1600-14gm, then captures an image of a corresponding lid, which is also processed by the VisionServer software to locate its position. This guides the robot into applying the clip, and the process is repeated for the second clip. As all lids have either three or four clips, the second robot applies the third and/or fourth clip downstream.
As well as managing the robot operation, ControlVision’s VisionServer framework also acts as the human-machine interface (HMI) for the system, enabling easy configuration of parameters and monitoring of the whole operation.
Since the clipper has been installed, clips are now applied to lids at a rate of one every two seconds. This equates to double the output of the previous process, with operators now able to run twice the volume of product, resulting in immediate labour savings for Sistema.
Another advantage is the system’s versatility, as Sistema Engineering Manager Oliver Jensen explains, “There’s no product changeover procedure, any lid on the conveyor can be clipped since the system looks for any clip position on a lid, regardless of the shape or size. For example, even if we were doing a run of round lids, if there was a square lid placed in between them, the clips would still be applied,” says Jensen.
ControlVision Managing Director David Berry says that the Basler scout cameras were ideal for the solution, “As the first vision guided robotic assembly system in New Zealand to operate on two moving conveyors, obtaining high quality images was vital. The Basler scout cameras have definitely delivered on that front, and we have a very successful solution as a result.”
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