VW is developing a heavy load robot that can operate in co-operation with employees with no physical safety barriers and adaptive safety zones.
Volkswagen is starting to introduce co-operative robots (or Cobots) into its manufacturing environment. Without compromising on safety, the company is taking away the physical barriers and relying on systems of sensors to detect human presence and modify the robot behaviour.
Volkswagen has released a video demonstrating the technology. In it, a robot can be seen moving in the background with a pattern of lights with green, yellow and red areas in front of it.
VW employee Karl-Heinz Häfner moves confidently towards the robot and is still in the green zone. As soon as he touches the first yellow area with his foot, the robot slows down. When the worker reaches the red zone, the robot stops abruptly. If Häfner moves his foot back out of the red zone, the robot starts to move again.
The video demonstrates that in such an environment, a human being can work safely in the immediate vicinity of an industrial robot without being separated by a fixed safety barrier. This is possible as a result of the laser safety scanner which reliably detects any movements of the employee. A high-level control system coordinates the movements of the human worker and the robot, slowing and stopping the robot as soon as the worker enters the relevant safety zones.
Dr Martin Gallinger, who is responsible for the further development of robot applications in Volkswagen Group Production, explains why the dynamic safety zones are so important for the production of the future: “Everyone is now talking about human-robot cooperation. To date, we have been concerned chiefly with cooperation with lightweight robots that weigh significantly less and carry lighter loads. Now we want to make industrial robots fit for cooperation with people. They can relieve the burden on human workers as large industrial robots can lift much heavier parts and pass them to people.” In future, robots will be able to provide active support to people. Another advantage is the fact that existing robots can also be used for cooperation with people, saving the investment required for new robots.
“Despite all the advantages of this new form of cooperation, one topic still has the highest priority for us – safety,” Gallinger emphasises. Safe working is ensured by highly advanced interactive safety zones. For test purposes, Gallinger’s team has developed a prototype fit for use in series production together with Volkswagen’s partners KUKA, Keyence Deutschland and Fraunhofer IFF. Colour coding gives the employee a clear and simple indication of the area where he can work without any impact on the robot (green). The safety zones are dynamically adjusted in response to the movement of the robot. For example, if the robot is working in the background, far away from the position of the human worker, the green, yellow and red zones are moved accordingly. If the human worker is in the yellow zone, the movement of the robot is severely decelerated and even stopped in the red zone. This means that the employees concerned are absolutely safe and have complete clarity concerning the safety zone at all times.
The prototype that has been developed confirms the technical feasibility of a new form of cooperation and an entirely new safety concept: “In the next step, we will be intensively testing and optimising the prototype together with our project partners, health and safety experts and production employees. We intend to use their feedback to develop the system together to the point where it is fully fit for use in series production,” Gallinger adds.
The video from Volkswagen can be seen below: