The global market for cobots is expected to represent almost 30 per cent of the total industrial robot market by 2027, that’s according to market research group, Interact Analysis. However, these ‘bots aren’t always the most suitable robot choice.
Arguably a credit to the industry’s promotional efforts, many professionals are scouring different robot suppliers with the sole mission to purchase a cobot. Why? This new technology has been marketed as the modern version of a traditional industrial robot. This tunnel vision often means cobots are purchased and then squeezed into applications they are not suitable for.
Take precise drilling as an example. Purchasing a cobot for this application wouldn’t be wise. The dangerous tool, which must be attached to the robot gripper, will most likely warrant positioning the cobot in a cage. Equally, the application probably wouldn’t benefit from the hand guided teaching that many cobots allow. As with many drilling processes, there are many drill patterns which are required to be dictated through offline programming. As a result, purchasing a cobot for this drilling application wouldn’t be recommend.
Automating manufacturing processes is a complex issue without a one-size-fits-all solution. Admittedly, some applications are ideal for cobots, but how can manufacturers determine what type of ‘bot is required?
The Case for Cobots
Conventionally, this breed of automation represents an unguarded, easy to integrate collection of robots that typically carry out repetitive tasks. Well, at least that is how cobots are marketed. Strictly speaking, the robotics industry does not acknowledge cobots as a separate entity to traditional industrial robots. Let me explain.
International standard ISO 10218 parts 1 and 2 define four types of collaborative features, including safety-monitored stopping, separation and force limiting requirements. However, these standards apply when humans work collaboratively with any kind of robot on the same production floor, regardless of the ‘cobot’ label.
This is an important distinction, as new robotics implementers may assume that any cobot is automatically safe for use next to humans. In fact, this can only be determined by thorough risk assessment.
The implementer may be in for a nasty surprise if the assessment deems expensive safety fencing must be put in place for the cobot to operate. Additional safety features can even result in very low operating speeds or multiple stops for a cobot. These necessary safety additions aren't free, which could add significantly to integration costs.
Suddenly, dropping a cobot onto the production line isn’t as simple as it initially seemed.
Selecting Industrial Robots
Before selecting a type of robot, manufacturers should define the application first. Then, it will be clear whether a cobot is going to fit the bill. Industrial robots are generally used for more labor-intensive tasks and have long been used to manufacturers to remove humans from dangerous processes on the factory floor. In arc welding for example, deploying industrial robots is an ideal way to protect human workers from the torch and flash used in this application.
Industrial robots can automate an extremely broad range of processes such as this unattended, with high levels of repeatability. What’s more, multiple industrial robots can be integrated for a fully automated production line, meaning they can handle applications that are not conducive to humans at speed, therefore removing operators from unsafe or unclean environments.
An important consideration, which is often overlooked, is that industrial robots can have collaborative features too. Improvements in safety technology now allows industrial robots to be used in collaborative operations, providing many of the same benefits that a cobot brings.
Of course, this collaboration can only be implemented after the appropriate risk assessment — but that is no different than when choosing a cobot.
Remember, it's the application that defines the ability for human and machine to collaborate. While vendors are eager to claim the term 'collaborative robot', it isn't always so black and white.
For high-speed applications, industrial robots will always win the battle. That said, if the application doesn't require safety guarding, then the initial investment of a cobot is low. However, this can only be determined through risk assessment.
Manufacturers should avoid deploying fleets of cobots. At their current stage of development, this robot type is lacking in speed and isn’t always able to work as collaboratively as it is marketed.
It is imperative that business owners assess the application and the needs of their business’ future carefully first, before making their decision on robot or cobots. Before parting with their cash, manufacturers should consider one important question — does the robot match the application?