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Robots, and particularly industrial robots, are programmed to carry out sure capabilities. The Robot Operating System (ROS) is a highly regarded framework that facilitates the asynchronous coordination between a robotic and different drives and/or gadgets. ROS has been a go-to means to allow the event of superior functionality throughout the robotics sector.
Southwest Research Institute (SwRI) and the ROS-I neighborhood usually develop functions in ROS 2 , the successor to ROS 1. In many circumstances, notably the place legacy utility code is utilized bridging again to ROS 1 continues to be quite common, and one of many challenges in supporting the adoption of ROS for trade. This put up doesn’t intention to clarify ROS, or any of the journey to migrating to ROS 2 intimately, but when as a reference, I invite you to learn the next blogs by my colleagues, and our companions at Open Robotics/Open Source Robotics Foundation.
Giving an outdated robotic a brand new function
Robots have been manufactured because the Nineteen Fifties and, logically, over time there are newer variations with higher properties and efficiency than their ancestors. And that is the place the query is available in: how are you going to give the potential to these older however nonetheless useful robots?
This is turning into a extra vital query because the round economic system has gained momentum and understanding of the carbon footprint impression of the manufacture of robots that may be offset by reusing a useful robotic. Each robotic has its personal capabilities and limitations and people have to be taken under consideration. However, the query of “can I bring new life to this old robot?” all the time comes up, and this precise use case got here up just lately right here at SwRI.
Confirming views of the digicam to robotic calibration. | Credit: ROS Industrial
In the lab, an older Fanuc robotic appeared to be a great candidate to arrange a system that would display fundamental Scan-N-Plan capabilities in an easy-to-digest means with this robotic that will be consistently out there for testing and demonstrations. The specific system was a demo unit from a former integration firm and included an inverted Fanuc robotic manufactured in 2008.
The demo envisioned for this method could be a fundamental Scan-N-Plan implementation that will find and execute the cleansing of a cell phone display. Along the best way, we encountered a number of obstacles which can be described beneath.
Driver updates
Let’s discuss first in regards to the drivers. A driver is a software program element that lets the working system and a tool talk with one another. Each robotic has its personal drivers to correctly talk with no matter goes to instruct it on the best way to transfer. So when talking of drivers, the dealing with of that’s totally different from a pc’s driver to a robotic’s driver. This is as a result of a pc’s driver could be up to date sooner and simpler than that of a robotic.
When system producers determine errors, they create a driver replace that may appropriate them. In computer systems, you may be notified if a brand new replace is accessible, you possibly can settle for the replace and the pc will begin updating. But on this planet of business robots, together with the Fanuc within the lab right here, it’s good to manually add the driving force and the supporting software program choices to the robotic controller. Once the driving force software program and choices are put in, a good quantity of testing is required to grasp what the adjustments you made to the robotic impacted elsewhere within the system. In sure conditions, you could obtain a robotic with the required choices wanted to facilitate exterior system communication, nonetheless, it’s all the time suggested to verify and ensure performance.
With the passing of time, the robotic won’t talk as quick as newer variations of the identical mannequin. So to acquire one of the best outcomes, it would be best to attempt to replace your communication drivers, if out there. The Fanuc robotic comes with a controller that permits you to function it manually, through a train pendant that’s within the person’s hand always. It could be set to computerized and it’ll do what it has instructed through a easy cycle begin. But all security methods must be useful and within the correct state for the system to function.
The fast place report of the robotic’s state is essential for the pc’s software program (on this case our ROS utility) to know the place the robotic is and whether it is performing the directions accurately. This place is usually often known as the robotic pose. For robotic arms, the knowledge could be separated by joint states, and your laptop computer will in all probability have a difficulty with the outdated robotic on account of reporting these joint states at a slower pace whereas in auto mode than the ROS-based software program on the pc expects. One solution to clear up this sluggish reporting is to replace the drivers or by including the right configurations on your program to your robotic’s controller, however that isn’t all the time attainable or possible.
Updated location of the RGB-D digicam within the Fanuc cell. | Credit: ROS-Industrial
Another solution to make the robotic transfer as anticipated is to calibrate the robotic with an RGB-D digicam. To accomplish this, you need to place the robotic in a strategic place in order that a lot of the robotic is seen by the digicam. Then view the projection of the digicam and examine it to the URDF, which is a file that represents the mannequin of the robotic in simulation. Having each representations, in Rviz for instance, you possibly can change the origin of the camera_link, till you see that the projection is aligned with the URDF.
For the Scan n’ Plan utility, the RGB-D digicam was initially mounted on a part of the robotic’s finish effector. But after we encountered this joint state delay, the digicam was modified to a strategic place on the roof of the robotic’s enclosure the place it might view the bottom and the Fanuc robotic for calibration to the simulation mannequin as could be seen within the images beneath. In addition, we set the robotic to handbook mode, the place the person wanted to carry the controller and inform the robotic to begin with the set of directions given by the developed ROS-based Scan-N-Plan generated program.
Where we landed and what I discovered
While not as straightforward as a undertaking on “This Old House,” you possibly can train an outdated robotic new methods. It is essential to know the management platform of your robotic. It could also be that an issue just isn’t together with your code however with the robotic itself, so it’s all the time good to ensure the robotic, related controller and software program work nicely after which search alternate options to allow that new performance inside the constraints of your out there {hardware}.
Though not all the time environment friendly in attending to the answer, older robots can ship worth while you systematically design the method and work inside the constraints of your {hardware}, benefiting from the instruments out there, particularly these within the ROS ecosystem.
About the Author
Bryan Marquez was an engineer intern within the robotics division on the Southwest Research Institute.