Wi-Fi signals enable gesture recognition throughout entire home (w/ Video)

Jun 04, 2013 by Michelle Ma
A hand gesture changes the TV channel using WiSee technology.

(Phys.org) —Forget to turn off the lights before leaving the apartment? No problem. Just raise your hand, finger-swipe the air, and your lights will power down. Want to change the song playing on your music system in the other room? Move your hand to the right and flip through the songs.

University of Washington have developed technology that brings this a step closer to reality. Researchers have shown it's possible to leverage Wi-Fi signals around us to detect specific movements without needing sensors on the human body or cameras.

By using an adapted Wi-Fi router and a few wireless devices in the living room, users could control their electronics and from any room in the home with a simple gesture.

"This is repurposing wireless signals that already exist in new ways," said lead researcher Shyam Gollakota, a UW assistant professor of and engineering. "You can actually use wireless for gesture recognition without needing to deploy more sensors."

The UW research team that includes Shwetak Patel, an assistant professor of computer science and engineering and of and his lab, published their findings online this week. This technology, which they call "WiSee," has been submitted to The 19th Annual International Conference on Mobile Computing and Networking.

The concept is similar to Xbox Kinect – a commercial product that uses cameras to recognize – but the UW technology is simpler, cheaper and doesn't require users to be in the same room as the device they want to control. That's because Wi-Fi signals can travel through walls and aren't bound by line-of-sight or sound restrictions.

This video is not supported by your browser at this time.

The UW researchers built a "smart" receiver device that essentially listens to all of the wireless transmissions coming from devices throughout a home, including smartphones, laptops and tablets. A standard Wi-Fi router could be adapted to function as a receiver.

When a person moves, there is a slight change in the frequency of the wireless signal. Moving a hand or foot causes the receiver to detect a pattern of changes known as the Doppler frequency shift.

These frequency changes are very small – only several hertz – when compared with Wi-Fi signals that have a 20 megahertz bandwidth and operate at 5 gigahertz. Researchers developed an algorithm to detect these slight shifts. The technology also accounts for gaps in when devices aren't transmitting.

A change in the wireless signal is shown in real time as a user moves his hand.

The technology can identify nine different whole-body gestures, ranging from pushing, pulling and punching to full-body bowling. The researchers tested these gestures with five users in a two-bedroom apartment and an office environment. Out of the 900 gestures performed, WiSee accurately classified 94 percent of them.

"This is the first whole-home gesture recognition system that works without either requiring instrumentation of the user with sensors or deploying cameras in every room," said Qifan Pu, a collaborator and visiting student at the UW.

The system requires one receiver with multiple antennas. Intuitively, each antenna tunes into a specific user's movements, so as many as five people can move simultaneously in the same residence without confusing the receiver.

If a person wants to use the WiSee, she would perform a specific repetition gesture sequence to get access to the receiver. This password concept would also keep the system secure and prevent a neighbor – or hacker – from controlling a device in your home.

WiSee technology uses multiple antennas to focus on one user to detect the person’s gesture.

Once the wireless receiver locks onto the user, she can perform normal gestures to interact with the devices and appliances in her home. The receiver would be programmed to understand that a specific gesture corresponds to a specific device.

Collaborators Patel and Sidhant Gupta, a doctoral student in computer science and engineering, have worked with Microsoft Research on two similar technologies – SoundWave, which uses sound, and Humantenna, which uses radiation from electrical wires – that both sense whole-body gestures. But WiSee stands apart because it doesn't require the user to be in the same room as the receiver or the device.

In this way, a smart home could become a reality, allowing you to turn off the oven timer with a simple wave of the hand, or turn on the coffeemaker from your bed.

The researchers plan to look next at the ability to control multiple devices at once. The initial work was funded by the UW department of computer science and engineering.

Explore further: Reflected smartphone transmissions enable gesture control

More information: www.sigmobile.org/mobicom/2013/

Related Stories

MYO armband to muscle into computer control (w/ video)

Apr 28, 2013

(Phys.org) —"Wave goodbye to camera-based gesture control." That is the confident directive coming from a one-year-old Waterloo, Ontario, startup called Thalmic Labs. The company is prepared to ship its ...

Microsoft hand research ripens Kinect for work (w/ video)

Mar 07, 2013

(Phys.org) —Beyond reading body motions, Kinect is getting a workup by researchers at Microsoft, now showing substantial control additions. Microsoft Research this week showed how Microsoft Kinect for Windows ...

Recommended for you

Oculus unveils new prototype VR headset

20 hours ago

Oculus has unveiled a new prototype of its virtual reality headset. However, the VR company still isn't ready to release a consumer edition.

Wireless sensor transmits tumor pressure

Sep 20, 2014

The interstitial pressure inside a tumor is often remarkably high compared to normal tissues and is thought to impede the delivery of chemotherapeutic agents as well as decrease the effectiveness of radiation ...

Tim Cook puts personal touch on iPhone 6 launch

Sep 20, 2014

Apple chief Tim Cook personally kicked off sales of the iPhone 6, joining in "selfies" and shaking hands with customers Friday outside the company's store near his Silicon Valley home.

Team improves solar-cell efficiency

Sep 19, 2014

New light has been shed on solar power generation using devices made with polymers, thanks to a collaboration between scientists in the University of Chicago's chemistry department, the Institute for Molecular ...

Calif. teachers fund to boost clean energy bets

Sep 19, 2014

The California State Teachers' Retirement System says it plans to increase its investments in clean energy and technology to $3.7 billion, from $1.4 billion, over the next five years.

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

antialias_physorg
3.7 / 5 (3) Jun 04, 2013
Argh...just now finished installing remotes everywhere (lights, computers, beamers, heating, ... ). If they'd have come out a few weeks sooner I'd have waited for this.

Though I fear it would suffer from the same problem as voice control: An inadvertent gesture (e.g. at a party) which is interpreted to turn the lights out...(OK, depends on the type of party whether that would be fun or not, I guess)

Tried it 10 years back with voice control. That wen real well for about a day until I played MC Hammer.
When the lyrics came "Stop! (Hammertime)" the system obediently shut itself off.

Damn.

antialias_physorg
3 / 5 (2) Jun 04, 2013
..well, more like 17 years ago now that I come to think of it. Time sure does fly.
Sean_W
1 / 5 (1) Jun 04, 2013
Don't get in a drunken slap fight with anyone. The neighbours will think your house is haunted when the lights and music start going on and off.
ODesign
5 / 5 (1) Jun 04, 2013
Nice trick, but a little scary. Could be used as spy technology and for covert surveillance.

see article "Using WiFi to see through walls". . .
http://www.extrem...gh-walls

alfie_null
not rated yet Jun 05, 2013
It strikes me that you could easily use this technique for intrusion detection. Aside from home use, this would be attractive to commercial concerns.
Claudius
1 / 5 (2) Jun 05, 2013
Nice trick, but a little scary. Could be used as spy technology and for covert surveillance.



If you think Big Brother is watching, perhaps the system could interpret a gesture with a single upraised middle finger.