Too dangerous so far
Robots are nothing new. As long ago as the 1970s, the Asea company (now ABB) built the first electrically powered industrial robots, and in recent years several companies have developed small collaborative robots, designed specially to work together with humans in collaborative systems.
However, the really large industrial robots – with a lifting capacity that may be as much as 200 kg – are not used in collaboration with humans. They have until now been considered to be so dangerous that they have been put to work in well-separated areas.
The Team of Man and Machine research project, or ToMM2 for short, has looked at whether such collaboration is at all possible, and if so, how.
“A lot of the work has been about risk – how can we assess and minimise the risks. We have also looked at how new technology, such as new types of sensor, can be used in the work. We’ve come a long way”, says academic leader for ToMM2 at LiU, Kerstin Johansen. She has come to the conclusion that collaboration between people and robots is fully possible.
Demonstrator at LiU
A demonstrator built by LiU in collaboration with Volvo Cars was recently put through its paces. In the workstation, a large industrial robot lifts a panel into place, such that it can be screwed in place by an operator. The operation doesn’t place any serious demand on the robot’s strength – the panel isn’t heavy – but it does require a considerable reach, and evenness in motion. In order to simulate the assembly line at Volvo, the robot arm moves three metres during the assembly operation.
A fence just over 1 metre in height is in place between the operator and the machine. No other physical barriers are used, and the researchers would really like to remove the fence, as well.
“The fewer impediments we have, the better. It means that the size of the workstation can be reduced, and that the factory area is used more efficiently. In this case we managed to remove all barriers except for one, and I think that we can be satisfied with that”, says Kerstin Johansen.
She sees collaboration between robots and operators as a part of the future for Swedish industry.
“Quite right. I believe that this can increase our chances of retaining industrial production in Sweden. And it can mean a better work environment for the employees if, for example, they can be spared some heavy lifting. I see it as a win-win situation.”
Thousands of Volvo robots
Volvo Cars, which set the specifications for this particular workstation at LiU, already uses several thousand robots in its production. But these are robots that work in isolation. Stefan Axelsson from Volvo Cars, who watched the demonstration, is very satisfied with the result – but is not sure whether this way of working will be introduced at the Gothenburg plant.
“The technology works: that’s what LiU has shown. But for us it’s more of a philosophical question, or a matter of principle, whether we want to use robots in this way. We must make a decision about machine maintenance, and we can’t be sure what the trade union will say. We haven’t reached a decision yet”, says Stefan Axelsson.
Much of the work within ToMM2 has been carried out by doctoral student Varun Gopinath, at the Division of Machine Design, who has recently presented his doctoral thesis. He emphasises how important collaboration is, both for large companies such as Volvo Cars and Scania, and for the various student groups that have carried out parts of the practical work. In addition, a local company has provided the sensor technology used in the demonstrator.
“Automation is spreading through society. We have shown how this way of working can be introduced into industry without compromising safety. It won’t solve all of industry’s problems, but it can definitively help”, he says.
The ToMM2 project also has an important sustainability aspect. If traditional industrial robots can be adapted to work with humans, it may be not be necessary to scrap them. Maybe they can be improved and continue in use. But much remains to be done. Technology is developing unceasingly: the communication interfaces must be made secure, and must have sufficient capacity for an increased exchange of information, etc.
Brief facts: ToMM
- ToMM started in 2013 with the aim of investigating forms of collaboration between large robots and humans. In addition to LiU and Volvo Cars, Scania, Volvo AB and Swerea IVF have participated in the project. The Vinnova Strategic Vehicle Research and Innovation Programme (FFI) has contributed a significant part of the finance.
- In the second phase of the project, ToMM2, LiU has constructed two demonstrators to investigate how the technology works, and to identify problems and challenges, not least with respect to safety. The first workstation was based on an idea from Scania, while the second, which has recently been demonstrated, was based on a suggestion from Volvo.
- The ToMM project is reliant on a project known as SCOR. The aim of SCOR is to create a general model for how to manage safety in a system in which humans and robots collaborate.
Translated by George Farrants