Going fenceless is one of the main reasons why end users consider purchasing a cobot
Dear robotics enthusiasts.
The following reasons behind behind the idea of a fenceless application are mentioned often:
- There is not enough space in my existing production line for adding a large robot cell
- The cobot shall be placed in an area where also interaction with workers is mandatory
- The cobot can only handle a certain spectrum of the parts, the rest must be handled by workers
- A cobot can be placed tomorrow at a different place and hence is more flexible
- Fenceless applications seem to be less complicated to integrate and thus costs are lower / we can do the integration by ourselves
Let’s have a look at these reasons in more detail.
Space requirements
It’s true, if you go fenceless your overall footprint can be reduced. However, there are already safety solutions on the market which help you to reduce the required floor space for your „classical“ robot cell with fences, too. You can either use hard stops which limit the travel of axes 1 – 3. These hard stops are easy to handle and effectively allow you to limit the work envelope of your robot. As a result, you can reduce the footprint of your cell significantly.
Friendly cooperation
Instead of hard stops you can also use a software solution to reduce the work envelope of your robot. Systems like KUKA Safe Operation have the advantage that they define safe rooms dynamically. Also the tools are being monitored. As a result, you not only reduce the floor space of your cell, you also achieve some sort of cooperation – meaning a „partly and temporarily shared workspace “. For instance, if you think about an end of line palletiser, you allow safe loading and unloading of a pallet on one side of the cell while the robot is working on the other side. In combination with a safety scanner, the velocity of the robot is effectively reduced to a safe level once a worker is interfering with the process.
Handling of a wide variety of parts
Another positive side effect of this concept is that you are running higher velocities (of your industrial robot) in absence of a worker plus you handle much higher payloads compared to using a cobot.
If it is not only about payload, but about a huge variety of parts (maybe you are running in the same line 80 % standardised parts, 20 % special parts), it sometimes makes sense that these 20 % are in general being handled manually, as the effort to automate them might be too high. In that case, you really need a cooperative solution. What does that mean? In a cooperative solution, contact between the robot and the worker is not intended, but cannot be avoided. This is the area where a cobot solution totally makes sense.
However, sometimes you may need more payload, as cobots typically give you up to 14+/- kg of payload and this is the gross payload, meaning including the gripper. In that specific case, there is the possibility to equip your industrial robot with a safety skin.
The following video shows an example for a pressure sensitive skin called „Airskin“ from Blue Danube Robotics.
Cybertech Airskin Palletising Cell
Flexibility
If you want to be flexible, cobots can be moved relatively easy from one place in your production to another. However, moving is normally not the hardest part. Setting-up your process (and in case of a fenceless application fulfilling all the safety protocols can be challenging.
On the other hand, there are highly standardised robot cells on the market, which can be moved in your production with the help of a forklift. Especially in the machine tool industry such solutions have become common, and the advantages are higher payload, higher robustness for the harsh environment with coolant and mist on the shop floor and shorter cycle times.
Cost of setting-up the process
If you go fenceless, there are certain safety regulations which you must fulfil. Cobots are typically easy to program, but you need to keep in mind that getting a safety approval of your application is mandatory. If you have never done it before by yourself, it totally makes sense to get some consulting or to purchase the complete process from your partner. Bringing your cobot tomorrow to a completely different station in your process can sometimes be so challenging. You even may end up having it running behind a classical fence.
If you enjoyed this article and found it helpful, please leave a like. I would also appreciate to hear from you about your own experience with cobots in the comments below and of course I am also glad to get feedback from you regarding further topics you want me to write about. Make sure to subscribe to my newsletter so that you never miss a new article.
Sincerely Yours
Andreas
PS: Don’t forget: It’s robotics Friday, so take a minute and discuss your next steps in factory automation!