Robots & Cobots: Influencing the Modern Factory

As automation in general continues to proliferate in factory environments, so too does the role of robots and cobots. Now an integral part of nearly every manufacturing process, robots and cobots work together to overcome production hurdles and ultimately streamline productivity. But what are the distinctions between robots and cobots and how can they specifically work to help your business thrive? Below, we’ll break down how robots and cobots work to improve your production process thus saving you time and money.

What’s the Difference?

In general, most people think of cobots as power and force limiting machines that enable operators to work safely side-by-side the robot ‘collaboratively’. Most consider a ‘fenceless’ cell to be the sign of a collaborative robot, but there is much more to the story. According to ISO Standard 10218-1, there are many types of collaborative operation including Power and Force Limiting, Speed and Separation Monitoring, Hand Guiding, and Safety-rated monitored stop.   Essentially, standard industrial robots can be made collaborative and fenceless by addition of safety-rated scanners and software to limit speed or motion, depending on the position of an operator.

The key distinction between industrial robots and cobots is that cobots have the power and force limiting features built-in, without the need for external sensors.  Cobots also typically have the built-in hand guiding/lead-through-teaching features which enable operators to train the robot path simply by positioning the arm and recording the points. 

Robots and cobots both have valuable roles in modern manufacturing plants and it is important to choose the best one wisely!  Users must review their applications carefully to evaluate and mitigate any potential hazards of the automation.   Risk assessments which follow the Robot Industry Association (RIA) recommendations should be completed prior to finalizing the cell design and selecting the robot model.  Even though a cobot can be deemed safe by nature of power and force limiting features, users need to evaluate potential safety hazards with parts, tooling and peripheral equipment. 

Advantages and Disadvantages

While we’ve highlighted a few of the differences between industrial robots and cobots, it’s important to understand the innate benefits and drawbacks they both provide. Here are just a few pros and cons to keep in mind when using robots and cobots:

1. Speed:
   In general cobots operate at slower speeds than industrial robots.  Most cobots have speed limits from 500-1000 mm per second in true collaborative mode, with potential to operate up to 2000mm per second, with addition of safety-rated scanners.  Industrial robots can operate at much higher overall speeds and faster acceleration/decelerations, thereby better suited for high-speed assembly and higher throughput tasks.  However, many applications simply don’t need the raw speed of an industrial robot and thus are well-suited for cobots. For example, the speed for fluid dispensing applications is limited by the material properties and fluid delivery equipment, typically no more than 1000mm/second.  Cobot speeds are in this sweet spot and extremely well-suited for dispensing applications.  Many machine load/unload operations simply don’t need the raw speed of an industrial robot and can be just as productive when tended by a cobot.
2. Programmability:
   Cobots can be easier to program for simple applications with the lead-through-teach feature. By simply re-routing or moving the arm of the cobot along a new path a factory worker can reprogram the machine and/or make necessary changes. Most cobots have many plug-and-play gripper and tooling options that also aid in the ease of programming an application as well as plug-and-play machine vision options. In addition, most cobots have intuitive teach pendants or tablets that provide the point and click features people have been accustomed to with devices like smart phones. These attributes make cobots a friendlier, easier-to-use option for the novice user. 
   
3. Payload:
   While industrial robots can handle large, heavy materials, most cobots on the market today thrive in handling lighter-weight products.  The majority of cobots are rated for anywhere from 3 to 15 Kg (6.6 to 33 lbs), with the heaviest payload cobot on the market currently handling 35 kg (77 lbs). Industrial robots on the other hand, have payload capacities ranging from 1 to 2000 Kg (2  to 4400 lbs).
4. Increased Safety:
   Both robots and cobots provide the opportunity for increased safety in the workplace by reducing employee fatigue and minimizing operator interaction with potentially dangerous processes. However, it is important to note that the implementation of either industrial robots and/or cobots does not eliminate the need for factory workers altogether. Rather, factory employees work in conjunction with these machines to create a safer working environment for everyone.  Operators can have the opportunity to ‘up-train’ to manage the robots and automation, providing them with higher earning potential and more rewarding work.
   
   

Nachi CZ10 Collaborative Robot