Using a Universal Robot to simplify machine vision applications
Several times a year we receive requests from customers to assist with a final quality inspectionof a complicated or large component. These quality inspection applications are often best solved using some type of machine vision sensor. In many of these applications, the individual machine vision tasks are easily handled, but there are often other complicating factors.
For example, the component to be inspected may be too large for the available number of pixels in the machine vision sensor to complete a reliable inspection task, or the requirements may be for the quality inspections to be made at various locations on the component, requiring multiple cameras. These applications can also be further complicated based on the number of SKU’s that can be produced on the same assembly line.
Take the example in the video below. This inspection task is to complete a mid-stage quality inspection on the motor assembly used in a weed eater. This includes four inspection tasks:
- Read a 1D bar code that identifies the motor SKU for readability and correct content.
- Read a 2D bar code on the top of the muffler that is a unique tracking number for the weed eater engine.
- Confirm that cap is on the gasoline tank.
- Verify the choke lever is in the proper position.
All four of these inspections are relatively easy to configure, but are complicated since all of the inspections are in different locations on the weed eater motor. This type of automated quality inspection is usually not implemented because the overall inspection would require four cameras, and all of the mechanical configurations to mount the units. This solution is also further complicated since the same assembly line can have multiple SKU’s and the various key inspection points can be located in different places based on the SKU.
A Collaborative Robot to the Rescue!
As can be seen in the video, a machine vision sensor is mounted to the collaborative robot (cobot) and moves to the correct inspection location required based on the SKU of the motor to be inspected. The machine vision job contains all the inspections required for the SKU. As the Universal Robot is moving to the correct inspection position, a command is sent to the machine vision sensor for the correct sub-inspection to perform.
When the Universal Robot is in position, it sends a trigger signal to the machine vision sensor. The machine vision sensor is keeping track of the cumulative results of all of the required inspections, and provides a GO or NO GO result for attaining the overall quality requirement. This modular approach to the machine vision inspection and interfacing with the Universal Robot allows for a complicated machine vision inspection task to be segmented into a series of easier tasks, all combined into an overall result.
While the video used in this blog is a proof of concept demonstration that was on display in the Microscan booth at the Automate 2015 show in Chicago, it demonstrates the ability to combine easy-to-use machine vision sensors with easy to use robotics, solving a complicated inspection application.
The use of the collaborative Universal Robot also allows this type of inspection routine to be added to assembly lines that include significant amounts of human assembly. The mounting base used for this inspection proof of concept is on rollers, allowing the inspection solution to be easily added to an existing assembly line, or moved within a manufacturing facility as needed.
The inspection system HMI is all based on the Microscan CloudLink integrated web server functionality as described in a previous blog. The only software running on the HMI computer is an internet browser. In this demo, we used Google Chrome. And do not forget about wireless! It is not included in the video, but a Wi-Fi access point was also included with the proof of concept demo to allow viewing the inspections on a tablet or smart phone. And the best part is that it took about 15 minutes to program the complete HMI display.
Let us know how we can help with your inspection requirements. Sometimes a new technology like the Universal Robot makes the solution a lot easier.