Unique technology will make gesture control more accurate
Controlling smartphones by a simple swipe of your hand is the latest innovation to be introduced to phone owners. However, radar sensors with higher accuracy would take the concept from gimmick to practical usefulness, according to researchers at Lund University in Sweden. They have developed a method that could detect much finer gestures – while also using a lot less power – opening up to new applications in the future, and to simpler ways of using the feature for consumers.
– Publicerad den 18 November 2019
The Lund University team have a prototype that uses pulsed coherent millimeter-wave radar to track movements. That any type of radar is involved in changing the song on your phone may seem surprising – you may only think of radar as a way of detecting airplanes at a much greater distance - but scaled-down radar is actually being used for gesture control already, for example by Google. The Lund University method, however, is different.
“We believe that our pulsed radar will, in the end, be the most accurate way to measure distance to an object. Together with other imaging information, this can be a winner”, says Lars Ohlsson Fhager, Assistant Professor in Nano Electronics at Lund University.
The researchers in Lund have demonstrated that a single pulsed coherent radar sensor can be used to detect and classify radar signatures at over 99% accuracy.
This is how it works: much like traditional radar, you send out a signal, there is a reflection from the object that comes back; it gives you information on the distance and movement of the object. You can use a continuous signal to do this, but that’s not necessary for detecting things that are a lot closer to you than an airplane is. A limited range is fine for the distances involved.
Instead, the Lund researchers generate a very short pulse to get a signal, and therefore use a lot less power, opening up to battery-operated applications. They also use coherent pulses, something that makes it possible to detect much finer gestures. This is because the phase information in a coherent pulse – in contrast to a non-coherent - carries useful information.
In the long term, the researchers believe that accuracy will be key to how people respond to gesture control, as it enables more ways of using the technology. Using it in the car, in the shower, within the “smart” home or Internet of Things, or with a smart watch, are all ways in which gesture control can move beyond just smartphones – if it’s good, simple and reliable, of course.
“In the future, I think everything will become much more intelligent, with sensors reading what we do, how we behave and what we want. Our behavior will fundamentally change - gestures could become a common language”, says Lars-Erik Wernersson, Professor in Nano Electronics at Lund University.
But what will drive the tech development beyond current versions of gesture control? There may be an even more important application.
“Pulsed coherent radar can potentially detect the properties of the skin, or changes in the skin, in the distant future. That would go beyond whether or not our latest gadgets use it”, Lars-Erik Wernersson concludes.