What Are the Different Types of Collaborative Robots?

28/06/2021

Collaborative robots come in four different types: Power and Force Limiting, Safety Rated and Monitored Stop, Speed and Separation, and Hand Guiding. Each of these types meets the standards set by the ISO Cobot Safety Guide. That means they can all work safely alongside humans.

Yet they also have their differences. Take the example of the Power and Force Limiting cobot to understand this point. It stands out from the rest due to its additional sensors. These sensors help it use standard industrial robots while remaining safe for human-cobot interaction.

The other three cobots lack this functionality. Though they make up for this ‘shortcoming’ by offering unique features of their own. Read on to know what those features are and to decide which of these four types of cobots could meet your requirements better.

1) Power and Force Limiting Cobots

Power and force limiting cobots stop operation on sensing contact with people. They have smart collision sensors and are equipped with physical features to prevent or minimize damage or injury in the event of contact. This allows them to work with (or near) humans.

Once a risk assessment ensures that it’s safe to use them, power and force limiting cobots won’t require any safety devices like vision systems, barriers, and external scanners. This reduces their upfront cost as you don’t have to purchase a plethora of safety equipment with them.

That isn’t to say that everything is great about these cobots. They are slower, smaller, and less powerful than the other three types of cobots. You cannot count on them to handle massive payloads either. Nor are they famous for their precision, which is currently lower than other cobots.

Based on their safety functionality, these cobots are divided into four major categories:

Joint Sensing

These cobots use joints to monitor the forces applied to their body. Some collaborative robots use force-torque sensors to accomplish this objective, others rely on the current of their motor. They are extremely easy to operate and are by far the best choice for human-cobot interaction.

Skin Sensing

These cobots use tactile sensors to monitor the forces that might be applied to their body. Upon sensing potential impact, the sensor sends instructions to the cobot to stop moving, thereby preventing collisions. They are relatively difficult to operate than joint-sensing cobots but are equally safe.

Force Sensor Base

These cobots provide the best of both worlds. On the one end, they are capable of handling massive payloads. On the other, they still provide a good enough level of sensitivity to work safely alongside humans. Though adjusting these cobots isn’t easy when compared to joint sensors.

Inherently Safe

Their name makes it clear what ‘inherently safe’ cobots are all about. They cannot hurt their fellow human workers in most ways imaginable, mainly because they only handle low payloads. Though the end-of-arm-tooling (i.e. a welding tool) you might be using with them could affect their safety level.


Updated 16/05/2022