Automated Kitting Solution with Robot Vision

KITTING CELL BECOMES ROBUST AND FAST

YES! (all uppercase and with an exclamation mark) was the response from Morten Hansen, Manufacturing Technology Engineer at Danfoss Drives A/S of Grasten (Denmark), when asked whether the company planned to use Roboception’s products in the future.

Danfoss was first introduced to Roboception when one of their integrators of choice, Denmark’s QRS – Quality Robot Systems, resorted to an rc_visard and the SilhouetteMatch software in order to implement a feeding solution that requires a robot to recognize and move up to 100 different components without manual intervention. [Read more about this use case here…]

“After the successful implementation of this feeding solution, we looked to Roboception first when we needed to improve a vision-based pick-and-place solution that we had already set up in one of our production lines,” says Morten Hansen: “This cell just wasn’t performing to our expectations.”

THE KITTING CELL: TOO MUCH DOWNTIME, TOO MUCH ENGINEERING, TOO SLOW

Morten Hansen
Manufacturing Technology Engineer
at Danfoss Drives A/S

The issue at hand: In a kitting set-up, a robot compiles an assortment of different parts, picked directly from the supplier’s pallets, into differing trays. A robot-mounted 2D camera was used to identify the required parts, and to pick and place them.

However, as soon as the positioning of the parts would vary – e.g. if a palette was slightly tilted, its contents were even slightly shifted or a supplier maybe changed their way of packing the parts – the set-up would run into problems:

“We simply had far too much downtime and engineering effort in the original set-up, and the cycle time wasn’t great either,” Hansen recalls. “With Roboception’s vision solution, we were able to add a third dimension into our process, making it significantly more robust and more flexible at the same time.”

“The new cell is running robustly and adapts to changes autonomously, and what’s more: We were able to reduce the cycle time from 40 to as little as 25 seconds, a pick-and-place operation per part now takes 7 seconds instead of 12 seconds in the previous set-up.”

3D VISION INCREASES ROBUSTNESS AND REDUCES CYCLE TIME

Two rc_viscores were mounted on rails above the cell. They are coupled with an rc_cube that runs both sensors, the rc_reason CADMatch software and some individual sorting strategies. AprilTags and a tailored software module in the rc_cube’s UserSpace (with no additional computing resources necessary) ensure a highly precise localization of the sensors in relation to the robot at all times. The vision solution is connected to the KUKA robot’s PLC via RestAPI. The robot, too, is mounted on a linear rail in order to access the full length of the cell.

This implementation actually is one of the first operational cells relying on the rc_viscore, the World’s first 12 MPi stereo sensor that Roboception introduced in 2022. Its high-resolution capabilities allow the sensors to be placed well above the fairly large workspace:

With two rc_viscores mounted at a height of 2,9 m, the entire 5 x 3 m² floor space of the cell is covered, while even smaller parts can be detected reliably. In Danfoss’ current set-up, the smallest part has a surface area of 1.5 x 5.5 cm and is detected with a sub-millimetric precision of 0.2 mm based on its CAD template. Avoiding an on-arm solution also directly affects the cycle time, as the image processing can take place while the robot is still executing a previous task.

A SOPHISTICATED MIX OF MACHINE LEARNING AND CLASSICAL IMAGE PROCESSING

Objects to be detected: A layer of coils

Left camera image

Intermediate detection result

rc_reason CADMatch detection result

rc_reason CADMatch detection result, including grasp points (green)

3D visualisation of detection result

A TAILORED SOLUTION, MINIMAL WORKFLOW DISRUPTION AND SCALABILITY

Last but not least, the team at Danfoss appreciate the constructive working relationship with the ‘Roboceptioneers’: Not only were the vision experts able to build on standardized products and optimize their use with individually tailored extensions, they also were readily available to support with solid simulations and testing prior to the implementation.

Coupled with the intuitive user interfaces and regular software updates, this resulted in a minimized installation time on-site as well as equally minimal training requirements for the users. Integrating additional or replacement parts into the kitting process will be easy to do using templates based on their CAD data; and once the first cell was successfully installed, it can now be replicated 1-1 without any additional engineering effort.

Overall, Hansen’s whole-hearted “YES!” to our initial question documents how happy Danfoss is with these results. No further details necessary, he must have thought – and rather, went on to prove his point: Building on some elements developed in this application (e.g. the tailored Software Module in the UserSpace, or the CADMatch detection templates), the next joint projects are already in the making.

ABOUT DANFOSS DRIVES

Danfoss Drives is a global leader in AC/DC and DC/DC power conversion, as well as variable speed control for electric motors. With the world’s largest portfolio of power converters, VLT® drives, and VACON® drives at their fingertips – and backing from a partner whose legacy has been built on decades of passion and experience – their customer’s journey to a better future is only just beginning. Visit website…