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Samsung Launches 3D Movement Recognition Phone
Shuttertalk reports that Samsung have launched the world's first phone equipped with a continuous 3D movement sensor. Movement sensors in mobile phones to date have been limited to slope calculations and applied to some games and bio-related features. The potential is there to do away with the need for complex keypads on mobile phones, MP3 players, digital cameras and other handheld products. Many functions will be controlled by movement instead of buttons.
Without tactile feedback, waving fingers in the air and making funny gestures to do things is a waste of time and customers will hate it.
You can use your optical mouse without it touching the tabletop too, but it isn't at all a reasonable way to operate it.
To date, movement sensors in mobile phones have been limited to slope calculations and applied to some games and bio-related features. However, the SCH-S310 can recognize continuous movement in 3-dimensional space.
Two technical problems with this that I see.
Accelerometers have accumulation errors that always render them inaccurate. For true accuracy you need an external point of reference.
Consider, your phone senses that it accerates 5 m/s/s for 2 seconds, it can compute its current velocity no problem.
Now in stopping it, sensor error causes it to think it's accerlated -4.9999 m/s/s for 2 seconds. It's stopped, but it thinks it has a nonzero velocity. Not a big deal yet, but over time these errors accumulate, and after a day or two your phone thinks it's cruising along at 500mph. Perhaps a constant decay term on the stored velocity can force the system to tend to zero over the long term.
But a second and bigger issue is that of frame of reference. For many of the applications described here, I don't care how fast my phone is moving with respect to the earth, I care how fast it is moving with respect to me. So if I get in a car in stop and go traffic, how does the phone discriminate that motion from motion I do with my hands? Or what if I'm just walking along trying to edit my phone book with gesture motions and someone steps in front of me and I stop short? bye bye Cindy, guess we won't be going out tonight after all.
Maybe very clever software design can mitigate this problem of discriminating intended from unintended motion, but it's a difficult problem.