Microsoft digs Doppler to effect gesture detection Microsoft Research took motion detection to new levels this week when it unveiled a new gesture recognition system for laptops. Called SoundWave, the rig utilises the Doppler effect, picking up subtle changes in sound wave frequencies to calculate how a user's hand is moving in front of a laptop. It's said to work even in …
No pleasing some people. One of the positive things that can be said about Microsoft is the hundreds of millions they spend on researching innovative ideas without tying the research to product development timescales or money making activities. Then publishing and sharing information rather than hiding it all in a secret base beneath a dormant volcano until the killer product is designed.
Put an 18khz noise out loud enough and I can hear it, and I'm in my 30s. I know the shops that have those stupid, ineffectual "anti-chav" sonic weapons installed on their premises because they affect me too. It's like sitting next to a really loud, broken cathode ray tube. Nice to know I'm having my hearing potentially damaged and it's all okay because it's been scientifically tested, and stuff.
Make the noise closer to 40khz or so and you'll be safely out of the range of human hearing, but good luck to anybody with a pet who buys one of these.
Unfortunately, very few laptop's sound systems will be able to generate a frequency that high - most computer audio cards have the reconstruction filters' corner frequency at 20kHz.
But I agree: For those of us who wear hearing protection when we (attend concerts|mow the yard|fly|shoot) and still can hear up there, this would be, shall we say, less than desirable.
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Are the speakers on most laptops capable of outputting 18-22kHz? Are the mics capable of picking it up?
It's supposed to work while you are playing music. Will the location tone be a nice sharp square wave, for maximum possible intermodulation distortion?
It will work on a laptop - the mic and speakers are in known positions. With a desktop? (ie will moving the speakers require recalibration?)
If you plug in headphones, is your head sufficiently acoustically transparent, and stationary, to allow continued operation/ (hint - no)
So, nice demoware, but I suspect reliable realworld operation will require dedicated transducers (which is not a barrier, but not quite as advertised)
but here's the thing - I move my hand towards a device at say, 2 m/s - speed of sound is 330m/s
the observed frequency is (330+2)/(330+0) x actual frequency, f, say 1.005 f
(the zero in the bottom line assumes you are not throwing your laptop across the room in frustration)
It's a long time since I've done any serious digital filtering but it isn't going to happen using active analogue. Perhaps someone more up to date than me can advise on the feasibility
They had to find some way of making the touchy, slidey, wavey Metro interface work on the desktop somehow. A touchscreen monitor and leaning across the desk isn't it.
They're still going to be disappointed when the Corp market refuses point blank to ditch millions of 4:3 screens in favour of doppler enabled, handwaft-detecting widescreen ones en masse though.
A USB waft sensor might do the trick if it were cheap enough, but there's still the pesky problem of the fact that it's as widescreen fixated as the office ribbon to consider.
Also: "...an inaudible tone between 18 and 22kHz...". The countdown to a class action lawsuit from those claiming it gives 'em a headache, if there's the chance of a quick buck in it, starts now.
"For years radios had been operated by means of pressing buttons and turning dials; then as the technology became more sophisticated the controls were made touch-sensitive--you merely had to brush the panels with your fingers; now all you had to do was wave your hand in the general direction of the components and hope."
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