A vision-guided robotic system, installed at New Zealand-based Sistema to automate assembly of the company’s food storage containers, has doubled the output at the factory compared to manual assembly. The robots were able to place clips on the lids of the containers at conveyor belt speeds with a tolerance of less than 0.5mm.
In the system, two conveyor belts carry the lids and clips separately in parallel. Encoder feedback is employed to enable accurate tracking of clips and lids on the moving conveyors. Upstream of the robots, a Basler Scout scA640-74gm camera captures an image of the clip, and its position is determined by VisionServer software from ControlVision, a company based in Auckland, New Zealand specialising in machine vision and robotics. Two DLP-300x300-WHI lights from lighting company, Smart Vision, are also part of the system.
Once the position of the clip is found, VisionServer guides one of the Dual Adept Cobra s600 robots to pick it up. A separate, higher resolution camera then captures an image of the corresponding lid, which is also processed by the VisionServer software to locate its position. This guides the robot to apply 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 cell, 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 system 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.
Another advantage is the system's versatility. ‘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,’ commented Sistema engineering manager, Oliver Jensen.
Thanks to the success of this project, Jensen says Sistema is now considering installing additional camera-guided robot clippers to further production lines.
