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Bridging the uncanny valley : Date:

How must robots, intelligent machines, and virtual worlds be designed so that people can accept them and successfully interact with them? The BHT (Berliner Hochschule für Technik) aims to answer this question with its new HumanVRLab, a research lab that is unique in Germany. It was funded via FH-Invest and enables transdisciplinary research between robotics, IT, medicine, and life sciences.

Humanoid robots and intelligent machines can be somewhat creepy: They seem to resemble humans but are not quite human enough for us to intuitively accept them as equal interaction partners. We perceive their movements as strange or even threatening, and when they speak to us, we automatically assume that they think and feel like we do – only to react irritated when they don't understand us.

In a largely empty room, a two-legged robot and a human stand side by side and seem to be talking to each other.
Having a chat: BHT doctoral student Manuel Weiß interacts with the humanoid robot Digit. © M. Gasch

This acceptance gap is called “uncanny valley”. To bridge it, it is necessary to explore the boundaries of acceptance and find out where the uncanny feeling begins and ends – which is precisely what the HumanVRLab aims for, says Prof. Dr Kristian Hildebrand. Hildebrand, who coordinates the project at the Berliner Hochschule für Technik (BHT), adds: “We want to answer the question of how technology must look and feel so that we can accept it, interact successfully with it, and at the same time remain autonomous as humans.”

As technology has many facets and can be used in many different ways, the HumanVRLab aims to unite various disciplines in a transdisciplinary approach. This is even reflected in the equipment: It consists of a robotics lab as well as a lab for motion tracking and virtual reality (VR), which also includes a so-called CAVE for VR applications, and is complemented by corresponding computer and server capacities for real-time computation, simulation, and AI applications. 

This might sound like a huge playground for technology and computer lovers but it actually is much more than that: The ideas that arise in the HumanVRLab and its collaborations extend far into other disciplines. In addition to the interaction between humans and machines, research topics also include the visualisation of complex molecules, the simulation of biochemical and pharmaceutical processes, or the seemingly simple question of how humans actually move.

That is why BHT research teams from biology, medicine and other life sciences are involved in the HumanVRLab, too. In addition, the university cooperates with the Charité Berlin, whose research interests include medical VR applications, as well as with companies in search of new ways to support their employees in hard physical labour.

Motion Tracking

In motion tracking, an elaborate camera system records every movement of the test persons and algorithms use this information to calculate movement sequences, degrees of freedom, and forces acting on joints and body parts. Conventional systems require so-called markers, i.e., reflective dots that are placed all over the body or attached to a motion tracking suit. Marker-based tracking is very precise, but not always practical. For therapeutic approaches, markerless tracking might be more convenient so that patients do not have to put on a special suit. In the HumanVRLab, both marker-based and markerless methods of motion tracking are being researched and optimised.

Er ist ein Berliner: The robot Digit is the first of its kind in Europe

But the centrepiece of the HumanVRLab probably is the robot Digit. At least it is close to Hildebrand's heart and even closer to that of his colleague, the robotics expert Prof. Dr. Ivo Boblan. Small wonder: Two-legged humanoid robots are rare, and there is only one Digit on the European continent so far – the one living in the Compliant Robotics Lab (CoRoLab) at the BHT.

The robot has only been in use since January 2022 because the manufacturing company in had to deal with delivery bottlenecks. Therefore, the arrival of Digit at its new home in Berlin was delayed by several months. It is the last missing piece of the puzzle in the overall concept of the HumanVRLab. And it also induces an uncanny valley effect that has to be bridged: Digit has two legs, two arms and a torso, but no head and no hands. “Therefore, one of our research questions is whether it would help if we gave him a virtual head using augmented reality,” says Boblan.

For now, however, the CoRoLab team is concerned with more fundamental questions. Currently, they are exploring the different ways humans can interact with Digit, for example via pointing gestures such as “Go and pick up that box over there”. Both the human's gestures and the reactions and walking paths of the robot are analysed to find out how well they actually understand each other and when or why the interaction fails.  

The HumanVRLab is more than the sum of its parts

Of course, the HumanVRLab did not arise “out of nowhere”. The BHT already had a strong focus on robotics and information technology before starting the project. However, Hildebrand and his colleagues aimed for a concept that is more than the sum of its parts: “The project was to bring together the various activities that already exist at BHT and thus release new synergies,” says the project manager.

About ten people sit and stand in a room, looking at a digital whiteboard and discussing with each other.
Having a lesson: The HumanVRLab also serves to train students from various disciplines. © Kristian Hildebrand

Therefore, the HumanVRLab has also connected with ongoing projects. For example, the BHT has developed a mobile virtual reality lab in a truck that brings technology directly to people, especially in rural regions. The VR truck is used to test whether virtual reality can help in the therapy of diseases, for example by supporting patients in the correct execution of therapeutic exercises. Another BHT project aims to develop an exoskeleton that supports workers in physically demanding jobs with hard labour and enables them, for example, to lift loads in a healthy way that is easy on the back.

Large collaborative projects require a lot of exchange

In the HumanVRLab, all these ideas have found a common home. “The overall concept is quite unique in Germany,” says Boblan. Putting together such a collaboration, however, is a major challenge for universities and colleges, where every chair and institute usually follows its own agenda. “For transdisciplinary projects on this scale, you need a certain amount of open exchange between the research groups,” Hildebrand says.

At the BHT, this exchange already existed in the form of regular meetings between the research groups. In these meetings, the idea for the project was born. Boblan and Hildebrand agree that the HumanVRLab is teamwork through and through – and that this is the only way to make such a large-scale collaboration work.

The FH-Invest funding to finance the implementation of the HumanVRLab expires in March 2022. However, this does not mean the end of the endeavour. On the contrary, the work is actually just beginning: The HumanVRLab is to be established as an institute at the BHT, and it is to be opened up to different groups of stakeholders. For students, it will serve as a teaching laboratory. The OpenVRLab will be open to the public, inviting people to visit and learn more about the techniques and methods. And finally, companies can use the equipment and expertise of the BusinessVRLab to implement specific product ideas. “This will provide fresh impetus for Berlin and the region,” Hildebrand believes. If he is right, then far more has been accomplished at the BHT than just another bridge over the uncanny valley.