Can I pick your brain?
·I am attempting to build a device for a quadriplegic friend of mine that will translate his head position into·2 reliable variables.(rotation and tilt) I will use this device to operate·various·gadgets that·I hope will increase his quality of life. My requirements are: 1. Measure horizontal rotation with a 180 degree range and 10 minutes of angle resolution, 2. Measure vertical tilt with·a 75 degree range·and the same resolution.·I need to be able to measure these two axis independent of x, y ,z head location. I initially thought of·building a lightweight halo and incorporating potentiometers since they would be closed loop and easy to calibrate, but I am having a hard time designing a halo that will remain calibrated when the head moves x,y,z.· My new thought is to build my own "headband" optical encoder that uses gravity as a base reference for the vertical movement and·"who knows" for the horizontal. Anyone have any ideas?· Is a BS2 or SX up to the task of decoding two optical disk at 60rpm? Is there an easy way to mount sensors to the wheel chair and triangulate? Any thoughts will be appreciated.
Jeff M.
Jeff M.
Comments
> I am attempting to build a device for a quadriplegic friend of mine that
> will translate his head position into 2 reliable variables.(rotation and
> tilt) I will use this device to operate various gadgets that I hope will
> increase his quality of life. My requirements are: 1. Measure horizontal
> rotation with a 180 degree range and 10 minutes of angle resolution, 2.
> Measure vertical tilt with a 75 degree range and the same resolution. I
> need to be able to measure these two axis independent of x, y ,z head
> location. I initially thought of building a lightweight halo and
> incorporating potentiometers since they would be closed loop and easy to
> calibrate, but I am having a hard time designing a halo that will remain
> calibrated when the head moves x,y,z. My new thought is to build my own
> "headband" optical encoder that uses gravity as a base reference for the
> vertical movement and "who knows" for the horizontal. Anyone have any
> ideas? Is a BS2 or SX up to the task of decoding two optical disk at
> 60rpm? Is there an easy way to mount sensors to the wheel chair and
> triangulate? Any thoughts will be appreciated.
>
>
>Jeff M.
Hi Jeff -
A noble effort on your part, but part of this may already be available,
Check this web site and see if it fits your requirements:
[noparse][[/noparse] http://www.orin.com/access/headmouse/ ]
Hope that gets you on the right track. I'll have to see if I can dig it
out, but I also found an AU site with adaptive PC software for handicapped
users, which used VARIOUS PC compatible devices for input. It even
permitted concurrent, alternative inputs (mouse + paddle + puffstick +
whatever else one had). Each could be used as the primary device just by
activation. Sort of ... round-robin inputs.
Regards,
Bruce Bates
http://products.analog.com/products/info.asp?product=ADXL202
Two axis accelerometer can measure 2 axis tilts.This could be easily
fixed in the head and will sense
x and y tilts.This device could give you 4 variables. Front tilt; back
tilt; left tilt and right tilt.
A low cost rotational could be done with one
Dinsmore Digital Compass Sensor
http://dinsmoregroup.com/dico/1490spec.htm
and a small magnet. The small magnet (fixed in the head) will override
the earth field if sensor is placed in the nearby then reading only the
relative orientation.
ACJacques
Jeff & Julia wrote:
>
> I am attempting to build a device for a quadriplegic friend of mine
> that will translate his head position into 2 reliable
> variables.(rotation and tilt) I will use this device to
> operate various gadgets that I hope will increase his quality of life.
> My requirements are: 1. Measure horizontal rotation with a 180 degree
> range and 10 minutes of angle resolution, 2. Measure vertical tilt
> with a 75 degree range and the same resolution. I need to be able to
> measure these two axis independent of x, y ,z head location. I
> initially thought of building a lightweight halo and incorporating
> potentiometers since they would be closed loop and easy to calibrate,
> but I am having a hard time designing a halo that will remain
> calibrated when the head moves x,y,z. My new thought is to build my
> own "headband" optical encoder that uses gravity as a base reference
> for the vertical movement and "who knows" for the horizontal. Anyone
> have any ideas? Is a BS2 or SX up to the task of decoding two optical
> disk at 60rpm? Is there an easy way to mount sensors to the wheel
> chair and triangulate? Any thoughts will be appreciated.
>
>
> Jeff M.