In The Public Eye

Sensors: Infrared- and motion-detecting hands-free technologies are making the leap into the home.

October 02, 2003|By Tamara E. Holmes | Tamara E. Holmes,SPECIAL TO THE SUN

Anyone who has spent much time traveling and has visited public restrooms has washed his or her hands under a hands-free faucet - one that switches on automatically whenever it senses the presence of hands.

Could such technology be headed for the home? It's already here, experts say. And they say that the technology has improved substantially over the past 10 years and is making its way into the lives of more and more Americans.

Technology that senses the presence of people has been around for years, primarily in the plumbing, lighting and security industries. Lights that go on when a person enters a room or area and shut themselves off when no one is around can keep electricity costs low and make intruders think twice before continuing into a suddenly lit yard. Likewise, home security systems that sound an alarm when they detect movement have been mainstay offerings by companies such as Brink's Home Security and ADT for some time.

"To put it into perspective, we had some initial [plumbing] fixtures that if you put a light bulb in a fluorescent light, when you turned on the light the fixture went on. It was comical," says Julius Ballanco, who has watched motion detection technology come of age in faucets as the editorial director for PM Engineer magazine.

Today, faucets aren't so easily tricked, Ballanco says. In fact, users can designate how far a person should be away from, above or below the faucet before it should come on. Not only that, but users can program how long the water should stay on and what temperature it should be.

Plumbing isn't the only area that has seen monumental improvements in motion detection technology.

When it comes to security, "If you have a camera that's outside in the parking lot and a small cat or a dog happens to go through, you don't want it to set off the" motion detector," says Mark Provinsal, product manager for iPix Security Group.

Today's motion-detection technology can differentiate humans and small animals by analyzing the size of the moving object, as well as such factors as the time of day that the movement takes place.

Some sensors that seem to be identifying motion are in fact picking up body heat or even light reflected from an object, rather than the actual movement of an object.

One of the most popular sensor technologies is Passive InfraRed (PIR), which detects the infrared light that objects and people emit. Such sensors tend to be used to monitor small areas. They are programmed to recognize the way the area normally looks. When an object moves into the area, changing its infrared lighting, the sensor goes off.

In the past, anything could set off a PIR sensor. "Think about a day where the sun's out and the clouds are kind of rolling in and out," says Provinsal. "A major shift of clouds going in front of the sun can really change the lighting and everything in the scene and that could actually set off an alarm. So companies are trying to advance the technology so the [sensors] can recognize, `Hey, that's just the clouds going over, that's not a big deal. That's just the wind blowing that bush. Don't worry about that.' "

Symmons Industries, which produces faucets that have sensors, uses Position Sensitive Detection (PSD) technology. Rather than detecting light, as PIR sensors do, PSD sensors detect the position of objects. In other words, when an object enters a designated position in relation to the sensor, it is activated.

"This type of technology is not susceptible to variations in lighting conditions, reflectivity of surfaces and things of that nature," says Bill Tracey, marketing manager for Symmons, based in Braintree, Mass.

As a result, a faucet will only turn itself on when a person's hands are a designated distance from the faucet. Once the hands are pulled away - even if the person is still standing in front of the sink - PSD-enabled faucets will turn themselves off.

Not all sensors are sightless. Video motion detection (VMD) technology uses cameras to monitor a given area and note and record movement in that area. Such technology has provided a significant boost to the security industry, says iPix's Provinsal, because security officials no longer have to sit through hours of videotape. Rather, they can depend on the cameras to tell them when it's important to look at the tape.

"What we try to do is augment the user by saying, `Take a look only if certain things happen,' " he says. When a camera detects motion, an alarm sounds.

Today's crop of sensors and motion detection devices don't just detect motion -- they analyze it.

"If you have a bush that's right outside your window and sometimes the wind blows, you don't want that motion [to set off] an alarm. So you can basically tell the camera what areas to look at for motion and which ones to avoid. So it's a little smarter than a sensor that just sits there and any kind of motion is setting off an alarm," says Provinsal.

Future products will become more capable, experts say.

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