What are collaborative robots – cobots and how do they work?
If you are reading this article, you have probably already heard about collaborative robots – cobots and are wondering if they might be right for you.
Perhaps you have a concrete problem among the most common: an operator performs repetitive and strenuous work and creates a bottleneck. Result: a line that slows down production and productivity that drops.
Meanwhile, you get the feeling that your competition is automating and you are not.
Have you heard a lot about collaborative robots – cobots, but have few certainties and many doubts?
Have you already requested a quote for a traditional robotic cell and been alarmed by the costs and complexity of installation? Collaborative robots – cobots were created precisely to address these situations, but let’s carefully examine both advantages and risks.
Compared to a traditional industrial robot, collaborative robots – cobots can be installed without cages and barriers that take up space.
But be careful: collaborative robots – cobots are not the right solution for everything. And those who sell them do not always emphasize this fundamental aspect!
In this article you will find an honest and impartial guide: how they work, where they excel, where they disappoint expectations, and — something rarely explained — what legal responsibilities you assume when you install one in your company. Because making the wrong choice is not just a matter of efficiency: it can become a problem of safety and civil and criminal liability.
What are collaborative robots – cobots
The term “cobot” comes from the fusion of collaborative and robot: these are robots designed to physically interact with humans in a shared workspace.
The difference from traditional industrial robots is substantial:
- Conventional robots are optimized for high speeds and heavy loads, and require fencing, physical barriers, and exclusion zones to avoid hazardous situations
- Cobots are designed to work side by side with the operator, without physical separations
The robotic machines manufactured by Trebi place extreme attention on the safety factor, and in fact the robots used are confined by safety guards specifically designed for cutting and deburring applications. The guards are designed to make the machine safe without compromising comfortable use of the machine: a typical problem with poorly designed machines is that the operator is forced to remove or bypass the safety features in order to work efficiently.
At Trebi we are particularly attentive to this aspect: the machines are designed to be safe, but at the same time to make the operator’s life easier. This translates into correctly positioned control systems, large windows in the areas of greatest visibility, and safe and ergonomic procedures and safety systems for using the machine in manual mode.
In Trebi robotic machines, the robots are also equipped with safe safety areas: the robots we use have a dual CPU: one to manage the normal operation of the robot, another that monitors only the robot’s position in space for safety purposes. We define a virtual safe box (the work cell) from which the robot cannot exit. The safety CPU continuously verifies that the robot is always inside the virtual box.
Therefore maximum safety and the best comfort for the operator.
Be careful though: this does not mean that a cobot can always operate without physical guards. The assessment depends on the specific application — an aspect we will explore further below.
To immediately understand the key differences, here is a direct comparison:
| Collaborative robots – cobots | Traditional industrial robot | |
| Workspace | Shared with the operator | Segregated area, mandatory fencing |
| Operating speed | Max 250 mm/s (collaborative mode) | Up to 8,000 mm/s |
| Payload | Generally 3–20 kg | From a few kg up to hundreds of kg |
| Programming | Hand-guiding, intuitive interfaces | Requires specialized technicians |
| Robot cost | Medium-high for the size | Lower for equivalent quality and size |
| Installation cost | Contained (if additional safety systems are not installed) | High (cages, perimeter sensors, etc.) |
The table simplifies for clarity. In practice, the choice between cobot and traditional robot always depends on the specific analysis of the application — there is no universally valid answer.
How collaborative robots – cobots work.
The technological heart of modern cobots are the torque sensors integrated into each joint. The operation can be summarized as follows.
Each axis has an electric motor coupled with a torque detection system
Advanced control algorithms calculate in real time the torque required for the programmed movement.
If the measured torque unexpectedly exceeds the expected threshold — this is interpreted as a signal detecting contact or an obstacle — the control system safely stops the cobot.
Manufacturers often present this feature as sufficient to guarantee safe collaboration.
In reality, safety does not depend on the cobot alone, but on the entire application. If the cobot is holding a sharp tool, even a timely stop may not prevent serious injury. The risk assessment must concern the complete system.
The importance of operational training for personnel.
An often underestimated aspect concerns the composition of the workforce: those who install collaborative robots – cobots must know their operators well. Those working in proximity to the robot must be adequately trained and must not have physical conditions that increase risk — for example bone fragility — which would make even low-energy contact potentially harmful.
A failure to carefully assess aspects related to operator-cobot interaction can expose the entrepreneur to legal risks, given the stringent regulations regarding risk prevention in work environments.
An important advantage: they are easy to program.
On the programming front, collaborative robots – cobots offer a concrete advantage.
Many models support hand-guiding mode: the operator physically guides the arm to record work points. Basic skills are sufficient to configure simple production cycles. Setup times are significantly reduced compared to traditional robots. Rapid reconfiguration makes them suitable for variable production and small batches.
Collaborative robots – cobots: where they are successfully used.
The main fields of application today:
- Component assembly
- Material handling and movement
- Visual quality control
- Light welding
- Packaging and palletizing
- Machine tool loading and unloading
The typical advantages of collaborative robots – cobots
In suitable contexts, the advantages are real and measurable:
- Simple integration: they fit into existing lines without structural upheaval
- Accessibility for SMEs: reduced footprint, contained energy consumption, lower initial investment compared to a traditional robotic cell
- Flexibility: quickly reconfigurable when changing products
- Ease of use: internal operators can manage basic programming without being robotics experts
- Intrinsic safety: designed to reduce the risk of injury in case of contact with the operator
Cobot sellers: what they don’t tell you.
Tell me about the limitations of collaborative robots – cobots.
This is the point that commercial presentations tend to gloss over. The limitations of cobots are real and must be understood before investing.
Cost: for equivalent size and build quality, a cobot costs more than an equivalent industrial robot, due to additional components (torque sensors, safety electronics). The cheapest models are often so because the build quality is lower
Operating speed:
in collaborative mode the maximum speed allowed by regulation is 250 mm/s. A conventional industrial robot reaches 8,000 mm/s. In high-rate production applications the cobot is not competitive
Payload and workspace: loads and reach are generally reduced — by definition, a cobot that lifts heavy loads can never be used in a truly collaborative way.
Not universal: in many applications the final analysis still requires physical isolation of the system, eliminating the main advantage
Collaborative robots – cobots: Trebi’s working method
At Trebi we have a “scientific” and “agnostic” approach to every customer request. The customer is always at the center and performance.
When Trebi visits a customer, its approach is not to sell what is in the catalog, but to understand the customer’s problem.
Every problem has the right solution. Often the same solution cannot work for different customers, even if they produce the same thing.
Therefore the method is “scientific”, we observe, we collect data, we frame the problem and we seek the solution.
And “agnostic”, there is no pre-packaged solution for everyone.
And to avoid increasing machine production costs and ending up with long delivery times, Trebi invented the “modular prefabricated” system. That is, the machine can be configured with the most suitable robot for the application and with the most suitable units for the customer’s problem.
This way special machines are created, always starting from a standard base. The best special solution, at the price and with the delivery times of a standard solution.
Collaborative robots – cobots follow the same logic.
If an application makes sense with the cobot, this is proposed; if it does not make sense, a traditional robot is preferred.
And for this assessment at Trebi we take into account all aspects and all phases of the machine’s life (from programming, to daily use, to maintenance, to efficiency, to productivity, to reconfiguration speed…)
We analyze the customer’s needs and their way of working and make the best choice to achieve the objective: automate efficiently at the lowest possible cost.
Collaborative robots – cobots: the case of complex industrial applications.
The theoretical fields of application are broad, but a 360-degree assessment often reveals non-obvious limitations. A concrete example: deburring aluminum castings. Apparently an ideal application, but the machining generates potentially explosive dust, which requires a closed cabin with dedicated extraction.
At that point the main advantage of the cobot — working in open space next to the operator — is lost, and with it much of its convenience.
Not surprisingly, despite expectations, the number of cobots actually installed in complex industrial applications remains limited.
Legal aspects relating to industrial collaborative robots
An aspect that rarely emerges in commercial presentations: installing a cobot independently means, legally, becoming a machine manufacturer.
EU Regulation 2023/1230 on machinery establishes that whoever realizes and puts into service the final system — not whoever produces the robot — assumes a precise set of obligations:
- Preparation of the technical file
- Risk assessment of the entire application
- CE marking of the system
- Civil and criminal liability in case of injury
Certification of collaborative robots: a concrete case.
It is worth clarifying a concrete case that often occurs: a company purchases a CE-certified machine tool and a separate cobot, also CE-certified. The two machines are connected — for example the cobot receives a signal from the machine to know when machining is complete.
At that moment the two machines become an assembly, and that assembly must be CE-certified as an integrated system. If it is the end user who has joined the two machines independently, it is precisely they who must take charge of certifying the assembly — not the original manufacturers of the individual machines.
In practice: if the cobot causes an injury, the liability civil and criminal is not that of the manufacturer of the robotic arm, but of the employer who configured and put the system into service. It is worth investigating before proceeding: a useful starting point is available at this link.
In summary:
Collaborative robots – cobots are a tool, not a universal solution.
COBOT YES
- The process requires flexibility and batches are variable
- Human-machine collaboration generates a real and measurable advantage
- Available space is limited
- The company cannot sustain the costs and complexity of a traditional robotic cell
COBOT NO
- Required speeds are high
- Loads to be handled are significant
- when the application requires physical isolation of the system.
- Cycle time is very fast
The right question is not “can I use a cobot?”, but “is this application truly collaborative?“. If the answer is yes, and if you are aware of the regulatory obligations that result, then collaborative robots – cobots deserve serious attention. Otherwise, a well-integrated traditional robot often remains the most effective choice.
Collaborative robots – Cobots: the advantage of contacting Trebi.
In any case, if the application is collaborative and you do not want to assume the risk of doing it yourself (acting as a machine manufacturer), you can contact a professional manufacturer who knows how to proceed and who provides guaranteed results and safety.
At Trebi we have years of experience in this type of application. We know that safety and efficiency are not contradictory: they must be designed together, from the beginning. If you are considering introducing a collaborative robot – cobot — or if you already have an application in mind and want to understand if it is really the right one — let’s talk!. We will help you make the right choice, not the easiest one to sell.
Take a look at the section dedicated to our products to get an idea of our working philosophy.
Our experience is built on decades of activity, carried out exclusively in the field of industrial robotics. At this link it is possible to explore the most significant milestones.
