Comments on: Sonar navigation jacket

By: Tyler J

Tyler J — Fri, 13 Mar 2009 18:17:16 +0000

One could just detect the +difference in distance between signals: Just have a sonar detector set up a constant (walking on level ground) and then only go off when it detects a positive change in distance past a certain threshold.

But, I don’t know anything about hardware =(

By: le'chef

le'chef — Sat, 22 Nov 2008 15:25:00 +0000

Void detection could be made pretty accurate if one added a accelerometer at the location of a forward and down pointing ultrasonic transducer. Work out relative position from the accelerometer and subtract from the ranging data.

By: Live for Improvement

Live for Improvement — Fri, 21 Nov 2008 22:42:34 +0000

That’s really neat, you should incorporate ear plugs that hum and change pitch as you get closer. That way you can gauge how far something is almost like a metall detector.

-Dan Malone-

By: chris

chris — Fri, 21 Nov 2008 16:43:40 +0000

Anybody remember this from startrek?

By: PKM

PKM — Fri, 21 Nov 2008 10:39:07 +0000

Not just blind people- I want one of these for the sides of my bike jacket, as a bit of advance warning when some ‘tard in a 4×4 forgets how road junctions work and drives straight into my blind spot.

It could be combined with the turn signal jacket: http://www.instructables.com/id/turn-signal-biking-jacket/
http://hackaday.com/2008/06/22/turn-signal-jacket-how-to/

By: robert

robert — Fri, 21 Nov 2008 04:48:26 +0000

If further developed, a blind person could appreciate this kind of innovation and not have to wear 50 lbs of equipment like previous guidance electronics. Great idea, you could market this.

By: japhy

japhy — Fri, 21 Nov 2008 04:28:30 +0000

detecting voids is just an inverse of whatever’s detecting solids, right?

Solid: 1 == BUZZ
Void: 0 == BUZZ

By: cde

cde — Thu, 20 Nov 2008 23:41:32 +0000

You would of course add tolerances for moving up and down. What you would be looking for is a large change in c, as a(length) and b(height) would have minor changes. C, the angle from the sensor to the floor would need to change by 1′ foot or more.

By: thyme3421

thyme3421 — Thu, 20 Nov 2008 23:25:55 +0000

good ideas… a large issue with this would be change of input, as the legs would be moving… so the change is constantly happening.

of course movement would depend on where the sensor is mounted. near the zipper at the base of the jacket might work, but there’s still a good amount of movement there… at the end of the sleeves would be ok, at least the person could keep their hand steady.

By: cde

cde — Thu, 20 Nov 2008 22:57:50 +0000

Use the a^2 + b^2 = c^2 formula. If you know the height, the angle, and the length (A b and c), a change to any of them would trigger the signal.

By: J4y

J4y — Thu, 20 Nov 2008 22:48:46 +0000

I think the idea about shoes having some kind of range finder sounds the one to try first. Question is how much warning does a person need to stop in time?

By: Ghrayfahx

Ghrayfahx — Thu, 20 Nov 2008 22:02:01 +0000

I was thinking she could use the same as the presence detection, but pointed at a 15 degree downangle. Then just make it vibrate (Differently prefferably) when it no longer detects something within a predetermined range. It should constantly detect unless there’s a void. have it only trigger when it loses input. Loss detectors are pretty simple and commonplace in the sensor world, so it should be easy to come across/build.

By: Edward Nardella

Edward Nardella — Thu, 20 Nov 2008 21:31:50 +0000

Perhaps a range finding device mounted on the wearers shin pointing just in front of their shoe.

-Edward@Nardella.ca

By: Jack

Jack — Thu, 20 Nov 2008 21:10:05 +0000

Possibly use some kind of analogue input device for the void detection? Like some kind of elongated wooden object perhaps? We will call this object a “stick”

By: localroger

localroger — Thu, 20 Nov 2008 21:05:19 +0000

For steps down, the thing would be to apply the same principle to the soles of shoes.