Cobot or industrial robot? Find out how to choose the best solution for production robotization

No safety fencing, lower cost, easy programming – does a cobot sound like the perfect solution? Whether it is the right choice for production depends on much more.

A cobot, or collaborative robot, is designed for applications where the robot needs to operate close to people. Thanks to built-in sensors and safety functions, it can respond accordingly and control its operation, for example by limiting movement or stopping the process. This makes it possible to design applications where an operator and a cobot can work in the same space.

Industrial robots are widely used in automated processes where factors such as productivity, speed, repeatability and the ability to handle heavier loads are important.

In practice, the differences between a cobot and an industrial robot mainly concern:

There is no single solution that will work best for every application. The choice should result from the requirements of the process.

A cobot can be a suitable solution where workstation flexibility and easy changeovers are important, and the tasks to be performed require cooperation with an operator.

Its use may be justified in the case of:

Cobots are used, among other applications, for machine tending, particularly CNC machine tending, assembly, material handling and quality inspection.

The International Federation of Robotics* points to their use in highly variable production and smaller production runs, where the ability to quickly adapt the robot to the next task is important.

Cobots are easier to program, and the large range of motion of individual axes gives them greater freedom when positioning the arm. This can make them easier to fit into limited spaces and adapt the robot’s trajectory to the workstation.

This does not mean that short production runs or variable production rule out the use of industrial robots. A properly selected industrial robot can also handle different variants and tasks, particularly when the process requires greater complexity, productivity and operation according to defined sequences.

An industrial robot is a natural choice where productivity, speed, repeatability or greater reach and payload are the key requirements.

It can be particularly well suited to processes that:

Industrial robots are used, among other applications, in welding, spot welding, palletizing, machine tending, assembly and material handling.

Higher payload, greater reach or higher operating speed can be crucial in more demanding processes. At the same time, the effectiveness of a solution depends not only on the robot itself, but also on how it interacts with the other components of the workstation.

That is why, instead of comparing robot parameters alone, it is worth looking at the performance of the entire workstation.

A cobot is designed with human-robot collaboration in mind. However, this does not mean that every cobot can automatically operate without safety fencing or other protective measures.

Safety depends on the entire application – not only on the robot itself. Factors such as the operation being performed, the tool, the component being handled and the organization of the workstation are all important.

The IFR** points out that the safety of a collaborative application depends on the specific task. A robot equipped with a sharp tool can pose a hazard regardless of the fact that it was designed to share workspace with an operator. Therefore, a risk assessment is also necessary for cobot applications.

For industrial robots, safety can be implemented through safety fencing, scanners, interlocks or other protective solutions. The final solution should result from the characteristics of the specific workstation.

The ability of a cobot to operate close to an operator results from its safety functions and the way the application is designed, not simply from the fact that it is a cobot.

An industrial robot can also operate close to an operator if the application and safety measures provide the required level of safety.

Robot selection should come after analysing the process.

The type of operation affects the required reach, payload, accuracy, method of gripping components and the equipment required.

If a short cycle time is critical, an industrial robot may have an advantage over a cobot thanks to higher operating speeds and the ability to perform repetitive movements smoothly. However, it is important to analyse the cycle time of the entire workstation, not just the robot’s movement speed.

When products, production runs or operations change frequently, greater flexibility can be an important argument for using a cobot. Similar flexibility can also be achieved with a properly designed industrial robot application.

If part of the process is still performed by a human, the way the operator and robot interact and the applicable safety requirements should be analysed.

It is necessary to consider not only the weight of the component being handled, but also the weight of the gripper or tool and the way the operation is performed.

In process applications where the robot performs milling or grinding, particular attention should be paid to loads on the robot resulting from high-speed drives.

A robot is part of a larger solution. Its operation is also affected by feeders, grippers, component positioning, vision systems, control systems, safety systems and product flow.

→ See how we design and implement automated workstations

The robot’s stated speed alone does not indicate how quickly the entire workstation will operate.

Cycle time is affected by factors such as picking up and placing the component, positioning, communication with other devices and the sequence of operations.

These elements can be analysed before the workstation is physically commissioned by using process simulation. It can be used to verify cycle times, robot trajectories and product flow, among other things.

This makes it possible to assess how the selected solution will perform in the actual process before it is commissioned.

→ See how simulation helps design and optimize production processes

Robot selection is just one of the stages of designing an automation solution. Equally important are workstation design, equipment integration, programming and commissioning of the entire solution.

The effectiveness of robotization depends not only on the choice of robot, but on how well it fits the entire process.

→ See how we design and implement automation and robotization solutions

No. Both solutions have different capabilities and applications. The choice depends on the requirements of the specific process.

A cobot can be suitable for processes where flexibility, frequent task changes or the possibility of working close to an operator are important.

In some applications, yes, but it is not a universal solution. For processes requiring high speed, high payload or high productivity, an industrial robot may be better suited.

Factors to consider include the type of operation, cycle time, payload, reach, production variability, operator involvement, method of feeding components and safety requirements.

Yes, but productivity is also affected by other workstation components, such as component feeding, grippers, positioning, communication and the sequence of operations.

Sources:

*  https://ifr.org/ifr-press-releases/news/how-robots-work-alongside-humans
** https://ifr.org/post/international-federation-of-robotics-publishes-collaborative-industrial-rob
*** LBR iisy: Industrial cobot for flexible manufacturing, assembly, material handling, and arc welding. | KUKA