Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sshhh, it’s listening: totally new computer interfaces

19.12.2007
Keyboards are a necessary part of today’s computers, right? Maybe not for much longer. A group of European scientists have used acoustic sensors to turn wooden tabletops and even three-dimensional objects into a new type of computer interface.

Sound vibrating a windowpane or through a tabletop is something most people experience daily. Sound waves travel well through most solid materials. Now, European researchers have exploited the excellent propagation of sound waves through solids to turn everyday objects – including 3D objects – into a new kind of computer interface.

By attaching sensors to solid materials, researchers from TAI-CHI, a project working with Tangible Acoustic Interfaces for Computer-Human Interaction, were able to locate exactly and track acoustic vibrations. Tapping on discrete areas of a whiteboard could generate musical notes on a computer. Tracking the sound of a finger scrawling words on a sheet of hardboard could translate, in real time, into handwriting on a computer screen. There is no need for overlays or intrusive devices.

Sensing vibrations in a solid and converting them to electrical pulses is the easy bit. Exactly locating the source of that vibration in a solid material is where it gets complicated. The problem is that the complex structures of solids make wave propagation difficult to model. Wood knots in a desktop, for instance, will alter how acoustic vibrations disperse.

Reading the signals
The TAI-CHI team investigated four main technologies. Time Delay of Arrival (TDOA) uses three or more sensors and compares the difference in arrival times of an acoustic wave at each of the sensors to establish location. In fact, the concept of TDOA has been around for about 100 years. Provided you know the propagation velocity of acoustic waves through the solid material, TDOA provides a very practical, if rather expensive, solution.

Time reversal, on the other hand, needs only a single sensor. It works on the notion that each location on the surface of a solid generates a unique impulse response which can be recorded and used to calibrate the object. Time reversal works on 3D objects just as well as flat surfaces.

MUlti-Sensor Tracking through the Reversal of Dispersion (MUST-RD) requires a deep understanding of the wave-dispersion properties of the solid. The dispersion curve of acoustic waves moving through the material under test is compared to a database of dispersion curves for common materials. From the comparison, the location of the vibration source can be calculated. (MUST-RD can also be used to give a crude estimation of a material type.)

Finally, TAI-CHI researchers worked with in-solid acoustic holography. Using sound pressure, sound intensity or particle velocity to calculate position and time, a sound source can be mapped and visualised in much the same way as an infrared camera can map heat sources. Some of the TAI-CHI researchers also experimented with a combination of acoustic localisation and Doppler tracking to locate and track sound sources moving through the air.

The range of researchers brought together by the project, part-funded by the European Commission – in Germany, France, Italy, England, Wales and Switzerland – was an important factor in its success, according to TAI-CHI coordinator, Dr Ming Yang of the University of Cardiff.

Specialist solution
Tangible acoustic interfaces like this are not going to replace keyboards and computer mice in the near future, says Dr Ming Yang. But in specific environments where keyboards are impractical – perhaps in very dirty environments or in hospitals where a keyboard might be a hiding place for bugs – TAIs could provide an elegant solution.

“Time reversal is a beautiful technology,” he says. “Unlike TDOA, it works with any object and it does not require special materials. Because it needs only a single sensor and a normal computer, it is very simple and cost-effective. One spin-off company from the University of Paris is working on commercial applications for this.”

Other technologies, such as acoustic holography, show great promise but are not ready for commercialisation.

CeTT, a Swiss member of the consortium, has put together a TAI-CHI Developer’s Kit, comprising algorithms developed during the project, software and hardware, as a one-stop-shop for application developers looking to build on TAI-CHI breakthroughs.

Other applications include a wireless sensor using Bluetooth technology that Dr Ming Yang would like to develop with commercial partners.

The time-reverse technology is the project’s major breakthrough, according to Dr Ming Yang. “Before, people were only working on easy materials. We have developed it for metal, plastic and board. We have a really interactive interface.”

Christian Nielsen | alfa
Further information:
http://cordis.europa.eu/ictresults/index.cfm/section/news/tpl/article/BrowsingType/Features/ID/89389

More articles from Information Technology:

nachricht Novel communications architecture for future ultra-high speed wireless networks
17.06.2019 | IMDEA Networks Institute

nachricht Concert of magnetic moments
14.06.2019 | Forschungszentrum Juelich

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Novel communications architecture for future ultra-high speed wireless networks

17.06.2019 | Information Technology

Climate Change in West Africa

17.06.2019 | Earth Sciences

Robotic fish to replace animal testing

17.06.2019 | Ecology, The Environment and Conservation

VideoLinks
Science & Research
Overview of more VideoLinks >>>