Tactile Feedback with Voice Coil Motors
Kevin A. Li, Patrick Baudisch, William G. Griswold, James D. Hollan
This paper describes two tactile feedback systems built to increase expressive range of haptic systems. The idea is to build devices that will be able to express output in terms of taps and rubbing in addition to traditional vibration used in current phones and game controllers. It is suggested that this would create a much more natural kind of touch feedback that could express a greater range of meaning.
The tapping and rubbing prototypes were constructed using hard drive actuation motors to power the motion. Signals from audio output were then used to control the movement of the motors to make it easier to create smooth motion that could be varied in frequency and amplitude.
The researchers then tested a variety of tips to put on the devices which would create the best tactile sensation. Once these were chosen the devices were tested with users in order to see how well people could distinguish amounts and intensities of movements as well as to get a qualitative assessment of the devices.
While not much of interest was found in the quantitative study (people could distinguish differing amplitudes and amounts fairly well) the qualitative study proved interesting. The test subjects were split on preference of frequency of the rubbing and amplitude of the tapping. Some felt that the faster rubbing felt more natural while others preferred slower. Similarly some subjects thought that soft tapping felt more natural while others thought that harder made more sense.
Another interesting result is that after a certain frequency was reached, the test subjects could not distinguish between tapping and more traditional vibrating sensation.
I think that these two inputs could be useful in hand held devices. For example if a phone could tap on your leg when you get a text (when it is in your pocket) it would be much more noticeable and quieter than current vibrating systems. Also rubbing feedback when the device is in your hand could provide much more intuitive than vibrating in some situations. The authors of the study also suggest that it could convey a better way to convey human emotions in messages as these inputs often felt like human interaction.
This is pretty interesting and kind of funny. I can just see a cell phone bugging me to answer, poking me over and over again. I can see people switching their phones to "no-tap" mode.
ReplyDeleteSeriously, though, this seems like a pretty cool idea. I have never really thought about alternatives to the vibrations used in cell phones and game controllers. I would like to see this innovation in some real world products.
Sometimes when my phone is on vibrate and I'm walking around, I don't even feel anything when I get a text message or a phone call. With something more subtle, I would most likely miss every call/text, unless I was sitting down. I guess having the ability to choose which style you wanted to use could be useful. Many people can still here a vibrating phone in a quiet room. Other methods (tapping, etc) could be useful in these situations.
ReplyDeleteI think that alternatives to vibrate are a very good idea. There are times when vibrate isn't enough and you don't feel it, and other times when it is too much like when you are taking a test and you can hear people's phones go off just as clearly as if they were on ring
ReplyDeleteSame here on not getting the vibrating. I think this tapping is a good idea. Good job delivering the meat of this paper. Hopefully things will be more integrated as the years go on.
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