# Sonar Navigation Jacket

[Lynne] had this crazy idea to build a piece of clothing that would give you feedback about your surroundings using sonar. She started with a carefully selected thrift store jacket. She wanted something that looked good and also provided plenty of places to hide electronics. She used the LilyPad system, with a vibration pad and a sonar range finder. When the system detects an object within a certain distance directly in front of the wearer, it warns them with some vibration. Not only is it practical, it looks pretty cool too. Did we mention she designs clothing?

She notes, in the comments section, that while it can detect an obstacle, it cannot detect a void. How could she detect a drop in the floor or a step down?

## 15 thoughts on “Sonar Navigation Jacket”

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

2. Jack says:

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”

3. Edward Nardella says:

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

-Edward@Nardella.ca

4. Ghrayfahx says:

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.

5. 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?

6. 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.

7. 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.

8. 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.

9. japhy says:

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

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

10. robert says:

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.

11. chris says:

Anybody remember this from startrek?

12. 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-

13. le'chef says:

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.

14. Tyler J says:

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 =(

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