Should I choose a cobot or an industrial robot?

09/04/2024

Cobot vs. robot: which one suits your production process?

In many industries, automation has become a necessary evolution, especially in manufacturing, where an extra robotic helping hand can make all the difference. A severe shortage of skilled labour, increasing performance pressure and the high expectations of end customers to meet ever stricter quality standards — these are familiar reasons that drive companies to seek support from a robot or its smaller sibling: the cobot.. But… what exactly is the difference between the two, and which one is best suited to which type of application?

How do cobots and robots differ from each other?

History

The word “cobot” comes from the English term “collaborative robot”, which literally means “cooperating robot”. In 1996, the cobot was invented to work collaboratively with humans within a shared workspace, unlike traditional industrial robots, which often work separately from humans for safety reasons.

The industrial robot made its debut in 1961 at General Motors. In the 1970s, robots made the leap to mainland Europe, and by the 1980s they had firmly established themselves in industry.

Where a cobot is intended to work in symbiosis with the human operator, the industrial robot is designed to perform its tasks autonomously. The most common applications include assembly, welding and handling of heavy components.

Differences

Cobots and traditional industrial robots differ significantly. Not only in their functional applications but also in their structural design and construction. These differences come with both advantages and disadvantages, depending on the specific application and working environment. At Cibo Robotics, we have found that these differences become even more pronounced when automating grinding processes.

Safety features

a. Cobots are designed to operate safely alongside people. They are equipped with advanced sensors that allow them to detect human presence and adjust or stop their movements accordingly to prevent collisions. They also operate at a maximum speed of 1 metre per second to minimise injury in case of contact.

For applications such as pick-and-place, assembly, dispensing or CNC machine tending, a cobot may be used on the shop floor without additional safety systems.

However, once you mount a grinding tool on it, different rules apply. The grinding tool becomes the most hazardous component and therefore dictates the safety requirements: the operator must be appropriately protected. This often means installing safety fencing or radar scanners. Once this is done, the cobot is no longer bound by the 1 m/s speed limit, and its speed can be optimised for the grinding process.

b. Traditional industrial robots typically do not have such integrated safety sensors and operate exclusively in enclosed, safeguarded environments to avoid human interaction.

With payloads frequently exceeding 150 kg, a human stands no chance in the event of contact, hence the strict separation.

Flexibility en mobility

a. Cobots are lighter and more compact, making them easy to relocate and deploy across different stages of the production process.

b. Traditional robots are generally larger and permanently installed, making them less flexible when it comes to reconfiguring the production line.

c. In grinding applications, mobility is far less relevant. The grinding process usually occupies a fixed position within the workshop or production department, as it is part of a larger upstream or downstream workflow.

Programmability

a. Cobots are designed to be easy to programm, even by personnel without extensive technical training, often via intuitive interfaces or by manually guiding the robot through the desired movements.

b. Traditional robots generally require more complex programming carried out by specialised technicians.

For simple operations, point-and-teach is more than sufficient and often faster than programming an industrial robot.

For more complex operations, however, you need full control over the path the cobot or robot follows. This requires an offline programming environment, such as RoboDK, or a full CAM system like SprutCAM.

We will explore this in detail in a separate blog post [link naar blog].

Indexing tables

An indexing table has one or more fixed stop positions indicated in degrees. These tables can be driven by a stepper motor, servo motor or direct drive motor, each with its own advantages and costs. Indexing tables are ideal for applications where workpieces need to be rotated to fixed angles for the robot, or for loading and unloading the cell.

Use case: Cibo Robotics

Cibo Robotics uses all three types of turntables when assembling robotic cells. They often combine an indexing table with two synchronised turntables. The cell always includes a turntable positioned outside the enclosure, allowing the operator to change workpieces safely and away from dust. The synchronised turntable is controlled via SprutCAM, where all parameters are stored within the programme. This CAM programme manages the movements and coordination between the robot and the turntable.

Conclusion

There is no single, definitive answer. The choice between a cobot and a robot must be evaluated case by case by people who understand both the sanding processes and materials, as well as robotics and automation.

To provide some guidance, here are the general rules of thumb Cibo Robotics uses when deciding between a cobot and a robot:

For heavy material-removal operations (welding, deburring thick edges, heavy plasma burrs, etc.) → choose a robot

Does the process involve multiple grinding steps? (automatic changes of abrasives and tools) → robot

Integration with other systems? (Is it controlled by other machines or external software applications?) → robot

Is a synchronised turntable or linear track needed? (functioning as an additional axis) → robot

At first glance, these rules may suggest that a cobot is never suitable for automating a sanding process. Of course, that is not the case. Every tool should be used for the purpose it was designed for — which in this context means that for light applications, single operations and stand-alone setups, a cobot can function perfectly well.

However, once the complexity increases or heavier operations are required, an industrial robot simply becomes the better and more future-proof platform.

View other Cibo Robotics articles:

Not every motor is designed for grinding!

Abrasive materials: essential for a successful project

The advantages of adding an turntable to a cobot/robot setup

How do I program a cobot or robot?

Automate your sanding process with complete peace of mind