Traditionally, industrial robots and workers have been separated, with robots performing tasks such as welding, painting, moulding plastics and palletizing. Industrial robots working at high speeds and often manipulating heavy, sharp tools and objects, have typically been fenced. Only authorised workers with special keys have been able to enter the robot cage, after power has been turned off – and only these workers are authorised to re-start the robot on exiting the cage.
A new breed of robots is now enabling manufacturers to use robots alongside workers in production lines where some tasks can be automated, but others either cannot, or are more productive when performed by humans. These robots slow down or stop when workers are near, and re-start automatically when the worker moves away. Many have force-limiting technologies and other design features that ensure they cannot harm a worker if a collision occurs.
Though the market for collaborative robots is highly promising, forecasts on its development are often over-hyped. The IFR will publish statistics on the supply of collaborative industrial robots in 2019, but estimates that in 2017, only 4% of the 381,000 industrial robots globally installed in 2017 were collaborative. IFR members report confusion among customers on what a collaborative robot is, when to use one, and how to ensure safety. The IFR has therefore recently published a paper ‘De-mystifying collaborative robots’ to clarify. Below are some of the main points:
What is a collaborative industrial robot?
Collaborative industrial robots are a class of robots that perform tasks in collaboration with workers in industrial settings. The International Federation of Robotics defines two types of robots designed for collaborative use. One group covers robots designed for collaborative use that comply with the International Organization for Standards (ISO) norm 10218-1 which specifies requirements and guidelines for the inherent safe design, protective measures and information for use of industrial robots. The other group covers robots designed for collaborative use that do not satisfy the requirements of ISO 10218-1. This does not imply that these robots are unsafe. They may follow different safety standards, for example national or in-house standards. Robots that work with humans in other commercial or non-commercial settings (for example healthcare, food preparation and in public spaces) are covered by separate ISO norms and will therefore not be included in the IFR statistics on collaborative industrial robots.
When to use a collaborative industrial robot
- For tedious, repetitive and unergonomic tasks:
Collaborative robots improve manufacturing productivity when used to automate tedious, repetitive tasks that do not need to be performed at very high speeds and that do not require human dexterity. These include fetching and carrying materials and parts, holding heavy parts in position for employees to work on them, feeding machines, conducting quality inspections and performing a variety of assembly tasks such as placing and screwing parts, applying adhesives and coating or polishing surfaces.
- In production lines that include workers:
Though the range of tasks a collaborative robot can perform is impressive, there are still many tasks that are easy for humans but hard to automate cost-effectively. These include dealing with unsorted parts and irregular or flexible shapes, or tasks that require continuous fine-tuning of pressure applied to surfaces in tasks such as polishing and grinding. The majority of production lines - particularly in assembly - are therefore most productive when they combine robots and workers, each doing the tasks they perform best. A key advantage of collaborative robots is that they can be easily incorporated into production lines working alongside humans.
- In short or variable production runs:
Programming collaborative robots is fast for most applications and doesn’t require extensive training. This makes collaborative robots viable for manufacturers with short or variable production runs as the robot can be quickly re-tasked to the new run. Collaborative robots can therefore be a good entry point to automation for the many small-to-medium-sized manufacturers that have not so far invested in robots.
Case studies describing some of the current most common applications of collaborative robots can be found here.
A common misconception is that a collaborative robot is by definition a safe robot. As with any other tool however, safety is task-dependent. A collaborative robot wielding a sharp tool or part will be unsafe around workers no matter how slowly it runs. Safety assessments are required for collaborative robot applications as they are for any other industrial machine.
Collaborative robots are already working alongside traditional industrial robots in heavily automated sectors such as automotive and electronics. As technology advances - particularly in the fields of grippers, sensors and vision – we can expect to see adoption of collaborative robots in a variety of new manufacturing sectors such as food processing and in manufacturing of consumer goods such as cosmetics.
Picture: © ABB