Human robot collaboration | where cobots really pay off

Collaborative robots don’t need humans. Because they enable automation where it used to be too narrow or too expensive. What they can do on their own.

Human-robot
Human-robot

The robot manufacturer Kuka developed the first cobot together with the German Aerospace Center for applications in industrial production. That was in 2004 and it was a predecessor of today’s LBR iiwa.
Lightweight robots helped achieve a breakthrough, however, the Danish start-up Universal Robots. That was in 2008 when the Danes launched the UR5.

What is a cobot and why are collaborative robots popular?

A cobot is a robot that can work directly with human colleagues without a protective fence. According to Torsten Woyke, Managing Director of the distributor i-Botics, they have a few advantages over large industrial robots: “They are light, can be transported and can therefore also be used flexibly.”
Furthermore, cobots could feel and, in combination with cameras, also seen. You save space since a safety fence is no longer necessary. The associated infrastructure will also become more compact. The biggest plus, according to Woyke, is their ease of programming.
There are different approaches to make this programming work even faster. At the ‘Technical University of Nuremberg’, for example, there is a project in which future robots will be programmed offline with the help of virtual reality and a motion-capturing studio. As scientist Christian Deuerlein explains, this could simplify programming when welding with the cobot, for example.

The company Drag & bot, on the other hand, offers a software platform for the simple, graphical commissioning and programming of robot systems. “This should also enable economical automation of small batch sizes,” says company founder Martin Naumann. Even non-experts are able to program collaborative robots.
The International Federation of Robotics (IFR) always speaks of cobots when the robots are designed according to ISO 10218-1 for collaborative use. The associated ISO TS 15066 also contains guideline values ​​for the maximum speed and biomechanical limit values for the collision between human and collaborating robot included.
“It should be emphasized that cobots are not commonly used as a replacement for traditional industrial robots in established processes, ” explains Dr. Susanne Bieller from the IFR. Instead, new markets and new applications could be opened up with cobots. They are therefore of enormous importance for the further development of the market.

In which applications do cobots show their strengths?

In recent years, Woyke from i-Botics – who sells products from Universal Robots among other things – has shown that only around two percent of all cobots are installed in collaborative applications. One speaks of a collaborative application when the workspace of humans and robots overlaps 100 per cent, i.e. humans and robots work in a shared workspace. This is the case, for example, when a human is working on a part while the robot is holding it in a certain position.
In Woyke’s experience, most cobots work in coexistence with humans and support the worker, so that the output within the application increases by up to 50 per cent through the use of a cobot. “They are just as suitable for simple as for complex tasks,” reports Woyke.
The robotics expert is certain that the most common cobot application is still loading and unloading machines. Many cobots are also used in assembly. Here they often also help with picking the right parts. “That directly increases the quality,” says Woyke. Because a robot does not reach into the wrong box and thereby hand over the wrong part. That can happen to a human worker.

Automation rate: where do most robots work?

Globally, an average of 74 robots work for every 10,000 employees in the manufacturing industry. This was announced by the International Federation of Robotics (IFR) in the latest statistics. Click through and see how Human robot density is distributed around the world according to the IFR.
At Schaeffler, HRC applications are already in operation in production. This was reported by an employee of the automotive supplier in his presentation at the ‘Innovative use of robots’ conference in industrial practice’ at the Technical University in Nuremberg.
An example is the supply of sensor covers for thermal management systems. A universal robot feeds the lids based on a camera. It is a co-existence because the collaborative robot is secured by a light grid.
Another application without a protective fence is found at Schaeffler for gripping and measuring housings for hydraulic support elements. In this application, the parts come out of the grinding machine and every 100th part has to be picked and measured for quality purposes. The reading is then fed back to the grinder.
Here a UR3 from the new e-Series from Universal Robots works in cooperative operation. To make this possible, Schaeffler carried out the necessary biomechanical measurements and avoided sharp edges in the entire HRC application.
Another area is welding. According to distributor Woyke, there is currently a great deal of demand in the area of ​​’welding with the cobot’. “This is really booming because it works more precisely than manual welding and also does not depend on the welder’s daily form,” explains the i-Botics managing director

What challenges are there when using cobots?

Due to the rules in the ISO TS 15066 technical specification applicable to human-robot collaboration (HRC), cobots are not allowed to move at full speed. This was also confirmed by Uwe Wachter from the automotive supplier ZF at the specialist conference ‘Innovative use of robots in industrial practice’ in Nuremberg.
“The challenge when it comes to human-robot collaboration is and remains speed because proper collaboration always increases the cycle time,” explains the head of the ‘Production Tech Center Robotic and Vision’. Current HRC applications at ZF, therefore, involve little interaction between the worker and the cobot.
The reasons are a lack of intelligence in the cobot systems and security requirements. According to Wachter, humans and robots work synchronously in 95 per cent of all cobot applications in the ZF Group. This means that although they have a shared workspace, there is usually no or very little interaction.
Humans and robots cooperate in five per cent of all cobot applications in the ZF Group. A collaboration – in which humans and robots work on the same product at the same time – does not currently exist in the group in series production. In most cases, cobots are used for pick-and-place tasks and palletizing, Wachter reveals.

How important are cobots in the market for industrial robots?

According to the IFR, the share of cobots in the industrial robot market is currently a good three per cent (as of 2018). “However, we see that this share continues to increase, with above-average growth rates compared to the industrial robot market,” says IFR General Secretary Susanne Bieller. From 2017 to 2018, the proportion had already increased by a good 20 per cent.
Cobots are not taking away any market share from industrial robots. “The areas in which we use classic industrial robots today will continue to be important in the future,” says Bieller. Because that’s where precision, repeatability, speed and payload are important. Bieller therefore expects robots to remain behind protective fences in the future.
Instead, according to the IFR, cobots will spread into new sectors, but also into new areas of application of established sectors that have been using industrial robots for many years. “It is also conceivable, for example, that more cobots will be used in the service area – and thus play a much more prominent role in our daily lives,” explains Bieller

How will the cobot market develop in the next few years?

Basically, the cobot market is developing very positively. “2019, for example, was a very difficult year economically,” explains woyke However, cobot integrators have increased their sales by up to 66 per cent, reports the robot expert. At the same time, the areas of application for cobots are increasing.
The manufacturer Rethink Robotics also wants to serve the service robotics market with its Cobot Sawyer and offers the so-called Cobot Café for this purpose. It is a barista solution for events or public areas where classic cafés would be interesting but cannot be implemented due to lack of space or for economic reasons.
Guests or customers can use an integrated tablet to choose from eight different coffee specialities and place their orders. Sawyer then moves, prepares the fresh coffee speciality in front of the customer and delivers it to the customer. “Possible places of use would be, for example, foyers of banks, museums or hotels, as well as lounges at airports or train stations,” explains Rethink Robotics CEO Daniel Bunse.
However, according to the IFR, there are also challenges. With the acquisition of SMEs and users from very different industries, a potentially very wide customer field has opened up in the cobot area. However, manufacturers and integrators would first have to develop certain process know-how.
In the early days of cobots, in particular, the impression often arose that cobots could do without any system integration at all, Bieller recalls. However, this is only the case for very simple applications. The risk assessment for more complex applications in particular requires a certain amount of experience.
It is also a misconception that cobots are the general answer to all questions. “Especially when high speeds, precision or high payloads are required, traditional industrial robots in combination with a sensor skin or similar cameras make more sense,” is Bieller’s conclusion.

These cobots are new to the market

Numerous manufacturers now offer collaborative robots. In addition to established companies such as Universal Robots, Kuka, ABB, Fanuc and Yaskawa, there are new companies such as Franka Emika, Doosan Robotics, Techman Robot and Yuanda Robotics. Cobot providers such as Elephant Robotics or Siasun are also emerging in China.
The collaborative lightweight robot CRX-10iA from Fanuc has been on the market since December 2019. It is lighter than all previous cobots from the Japanese manufacturer and can therefore also be used as a mobile robot on a driverless transport system. Its load capacity is 10 kilograms. The cobot’s user interface is designed in such a way that it is also suitable for users with little programming experience.
Yaskawa also launched a new cobot in December 2019 with the HC20. It offers a payload of 20 kilograms and is currently the strongest lightweight robot in the world. Yaskawa intended it as a so-called hybrid robot. Safe switching between industrial speed and collaborative speed – when supplemented with external safety technology – ensures optimal performance.
Torque sensors in each joint stop the robot safely in the event of a collision. According to the manufacturer, the so-called retract function ensures that in the event of a jamming situation, the robot moves back within its taught path so that the human colleague can free himself. The robot can also be gently pushed away during its movement if, for example, it should stand in the way of the employee during his or her work.

Rethink Robotics GmbH presented the new Sawyer Black Edition for the first time in October 2019.” After taking over the assets of the then insolvent Rethink Robotics Inc. just a year earlier, we modified the drives, for example,” reports CEO Daniel Bunse.
Individual mechanical components were also replaced and higher-quality materials were used. The result is that the Black Edition is more reliable and stable compared to the previous model. “In concrete terms, these improvements are reflected in a significantly lower failure rate and smoother running, which makes Sawyer’s movements more even and harmonious, and minimizes noise emissions,” says Bunse happily. This contributes to a quieter working environment.