Collaborative robots have been a high growth segment of the industrial robotics industry. At the time of this writing collaborative robots represent roughly 3% of the robot market, but that is expected to grow to 35% by 2025. Of course, the overall robot market will also be much larger by then as well, but nonetheless the numbers have a lot of people excited to jump on the cobot trend. And why not? These human friendly, sometimes bubbly looking cousins of the cold industrial robot can run without guarding. So why not make the switch? Well the short answer is because it's a little more complicated than that.
Choosing the wrong type of robot can be a huge productivity setback, so we set out to detail the pros and cons of cobots vs robots to help you make the right decision.
First, it is important to note some important terminology and define what we are talking about.
A robot designed for direct interaction with a human within a defined collaborative workspace.
A safeguarded space where the robot and a human can perform tasks simultaneously during production operation.
A state in which purposely designed robots work in direct cooperation with a human within a defined workspace. (More on this later)
There are four types of features that can be mixed/matched for collaborative operation of robots. Note that all of the below can apply to traditional industrial robots and cobots. The differentiator of a cobot is how much of the below is inherently designed into the hardware.
Safety-Rated Monitored Stop
Operator may interact with robot when it is stopped. Automatic operation to resume when the human leaves the collaborative workspace
Operator in direct contact with the robot, using hand controls
Speed & Separation Monitoring
Robot/hazard speed is reduced the closer an operator is to the hazard area. Protective stop is issued when operator is in potential contact
Power & Force Limiting
Incidental contact between robot and person will not result in harm to person.
Speed & Safe Speed
Part of what makes a cobot so safe is that it is not allowed to move at a speed that could harm a human should they interfere with the robot's workspace. This is not something a non-collaborative robot has to worry about and will thus be much faster.
When writing a project specification, it is important to note the speed difference as it can have a potentially game-changing effect on overall ROI over the lifetime of the robot. How many parts per minute are you looking to achieve? If the robot operation time were to be cut down, could the rest of the process catch up and run more efficiently? In a pure test of speed, a cobot will absolutely not be able to catch up to the non-collaborative's higher speeds and more efficient motion.
Movement & Guarding
They say you can't teach speed, but maybe speed isn't a key performance metric in your application. The process should be driving the robot decision and if the robot is not the potential bottleneck, we might be back into collaborative territory once again.
For example, if a robot is being considered to tend a machine where product flow is (and will continue to be) the drain on the system, a collaborative robot could provide a more simplistic solution that would not require guarding, doors, and other periphery.
This benefit could be amplified if the plant is running for 2 full shifts, but the machine was only running for 1.5. By mounting the cobot to a cart, the robot could be wheeled and locked in at other areas of use around the plant the remaining 1/2 shift. Something that is definitely possible with a traditional robot, but certainly not as easy. As opportunities such as this will release some of the pressure for plant rigidity and facilitate the use of more unstructured environments.
Programming & Flexibility
Hand guiding to teach points is a popular feature on cobots. To use the machine tending example above; maybe we do not know the type of machine or exact operation the robot will be doing on this fill-in shift. As long as the robot's motion paths do not have to be high precision moves, some hand guidance to quickly touch up some points could be a great asset to get things up and running quickly.
Misconceptions About Collaborative Robots
Cobots Are The Only Option For Humans To Collaboratively Work With Robots
Robot collaboration is possible in industrial robots through safety rated hardware and software additions. Safety rated scanners or pads can be integrated into the system in order to use the advantages of traditional industrial robots, while keeping workers safe without guarding.
See a great example on display here.
Cobots Are Always Safe
Sorry. It's just not that easy. In order to be RIA compliant you'll have to join every other robot application and conduct a risk assessment on your system. After all, your cobot might be safe when you purchase it, but once you give it an end-of-arm-tool and start moving around something dangerous, you're not really all that safe. The full application must be accounted for and the robot may have to be slow down or even require full guarding to protect it.
Cobots Are The Only Solution For High Mix, Low Volume Applications
It is at times thought that high mix applications require a cobot in order to be ready for frequent reteaching. By using vision guided robotics, force torque feedback, and creative programming techniques, industrial robots can access large amounts of information about the world and how they are affecting it. This data can then be used to make precise on-the-fly decisions that allow the robot to run at high speed and pinpoint precision.
Human-Human Collaboration Is Still Key
Standards and technologies are constantly changing and we've only scratched the surface. Luckily human-human collaboration is alive and well and IAS is ready to help your next robot application be your best. Contact IAS to find out more.