In the immediate vicinity, the white cane offers information about the environment, but it does not show where the passage between house fronts in some distance away is. Radar-based systems developed by the Ravis-3D project consortium can do this. The systems, which can be used intuitively, capture the environment and convert it into audio signals that are output via a semi-open hearing aid. A RUB research team developed various sensors and systems for the project and tested them together with those affected. "The amazing thing was that it was above all the simple, intuitive systems that gave the most positive user feedback," reports Prof. Dr. Nils Pohl, Chair of Integrated Systems at RUB.
A total of three chairs at Ruhr-Universität Bochum (RUB) and several industrial partners have completed the three-year project, which was funded by the European Union and the state of North Rhine-Westphalia.
Sensors, antennas, audio
The consortium first set about developing what was technically feasible. They built different radar systems, ranging from rotating 360-degree sensors and special antennas that capture the user's field of vision to directional sensors that measure the distance of a focal point. The researchers also used their bag of tricks for the audio output of the environment: For example, the system analyzed the noise environment and then faded out the obstacles that emit sounds themselves.
Accurately integrate into the acoustic environment
"The system should not perceive acoustically active obstacles, such as a speaking person, as an obstacle, since the user is already aware of them," explains Prof. Dr. Rainer Martin from the Chair of Communication Acoustics at RUB. The spatial localization of sources was further improved by measuring the individual hearing ability of users. "We wanted to achieve that the sound of real obstacles or navigation instructions is integrated as accurately as possible into the natural acoustic perception of the user," says Prof. Dr. Gerald Enzner from RUB communication acoustics.
This, in turn, was of particular interest to the companies involved in the project, Kampmann Hörsysteme and “Sensor-based Neuronal Adaptive Prosthetics”, or Snap for short. Their task was to test the systems with those affected and to integrate hearing aids for audio output. One system in particular has stood out positively: A relatively simple sensor system that can be hold in one direction like a flashlight to hear the distance to the next obstacle as a sound. "In connection with the audio output via hearing aids, this results in a virtual cane that can be operated intuitively and that works over a large area," explains Dr. Corinna Weber from Snap.
Great commercial potential
The consortium members are confident that the Ravis-3D results have great commercial potential. "There is no such system on the market yet," says Dirk Kampmann from Kampmann Hörsysteme, which heads the consortium. “We now have to work on making the components smaller and cheaper and on the system being well integrated into other IT-based aids for the blind, for example on smartphones. If that succeeds, we can enrich the market for blind aids in the coming years.”
A film sequence showing how the virtual cane works can be found on the RUB News page at https://news.rub.de/presseinformationen/wissenschaft/2019-08-06-elektrotechnik-virtueller-blindenstock-hilft-bei-der-orientierung. There is also a short film by RTL West on the subject on TVNow at https://www.tvnow.de/shows/rtl-west-89/2019-08/episode-1-thema-u-a-totes-baby-1670455 (Minute 15:38). (Photo: RUB/Kramer)
