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Hand-Mounted Sonar For the Blind
GeekTech.in writes "The Tacit, a wrist-mounted sonar device with haptic feedback, is like strapping a bat to your wrist to help you see. It makes use of two sonar ping sensors to measure the distance to the nearest obstacle. The relative distance to an object is then fed back to the user using two servos which apply pressure to the back of the wrist."
The good news is that it's users will never know.
"I've got more toys than Teruhisa Kitahara."
And it should've, damnit.
Keep reading for more information, build notes, parts list, schematics, and code. ...
Important Note #2: The circuit and software is released under a Creative Commons BY-NC-SA license, which I think of as a "Don't be a jerk" license. In short: Make it, learn from it, teach it, improve it, modify it. Just share what you do, give credit, and don't sell any without contacting me first.
PARTS LIST?!? CIRCUIT INFO?!? WOOOT! Now this looks like a damn fun toy.
vos nescitis quicquam, nec cogitatis quia expedit nobis ut unus moriatur homo pro populo et non tota gens pereat.
...like strapping a bat to your wrist to help you see...
From TFA:
This is a project I'm calling Tacit. No, I didn't bother making an awkward backronym for it....
I think he's not telling us everything. I'll bet the T in TACIT stands for pteropine... it's just that the 'p' is tacit......
You've obviously never heard of Ben Underwood (http://en.wikipedia.org/wiki/Ben_Underwood#Ben_Underwood), whom is often listed among the top ten contemporary inspirational people. Not only was he able to "see" using echolocation via clicking noises with his tongue, he excelled at tasks such as mountain biking. And he is not the last blind person able to do so.
That kid is amazing. Not only can he ride a bike around like any sighted kid, he can also play basket ball incredibly well.
I recommend anyone unfamiliar go dig up some videos of this kid in action.
Required reading for internet skeptics
Yeah, a portion of blind can see via clicking. I watched a documentary on this and the pitfalls of it. Apparently clicking can only let you see on a "2d plane", clicks are only reflective off of objects within your horizon. Meaning that you will not know about sudden drop offs until you fall into them.
So, because clicking is basically sonar, I am thinking this device has the same fault.
Blind humans can do a better job of echolocation just with there ears. Check it out (An amazing more complete version, but it's long).
There's even a school that helps teach echolocation to blind people, based in California, I believe. Wikipedia has a basic writeup on it.
Seriously it's pretty amazing to think that a human can develop echolocation ability. But we can.
"First they came for the slanderers and i said nothing."
The augmented sensitivity of hearing doesn't immediately happen when you go blind, it's something that improves over time, as an individual's senses are forced to compensate. I can see this being very useful for somebody who just lost their sight, or a blind individual who doesn't feel like attending a class.
It's another option on the table, and that's exactly what I believe it was intended to be.
vos nescitis quicquam, nec cogitatis quia expedit nobis ut unus moriatur homo pro populo et non tota gens pereat.
You've obviously never strapped a wild animal onto your wrist.
Analogies don't equal equalities, they are merely somewhat analogous.
And when someone hassles you too much, you just set it on 'stun' and give them a blast with it.
Sheesh, evil *and* a jerk. -- Jade
I would venture that the 2d limitations of natural human sonar have more to do with the fact that our ears are in a horizontal plane and thus can't distinguish up/down variations. Except in special circumstances, the air through which the sound is travelling is not going to be stratified enough to make a difference.
Given that, this is likely to sidestep that limitation, since it appears far more directional, and mounted on a hand, which is more natural to tilt than ones head.
You can hide your cigars in it if the nurse doesn't let you smoke.
But if it's only sound-based, it's doomed to fail.
Back in college (which wasn't exactly eons ago) I was programming robots to maneuver spaces using 1) a camera and 2) sonar and 3) infrared. As cool as sonar was, it had two major drawbacks. First, it could only check distance about once a second (partly due to the fact that there were 12 of them, but you get the idea). Second, the sound was very prone to being absorbed (fabric on a cube wall) or dispersed (angles). This resulted in some amusing thumps as the bot would get a no-response from the cube wall, think that it was wide open, turn to it, and floor it.
Add some EM sensors and then you'll have something that makes the life of a blind man easier.
Easily justified by the presence of a priori information. You know what an airplane sounds like and that unless you're at an airport, one would hope that it's in the air.
Simply put, humans are incredible sensor platforms, able to synthesize information from both simple and complex sources. Nonetheless, your ears are essentially two point sensors, so while you can distinguish quite a bit by hearing alone, azimuth by differencing the volume to each ear (of course there's a front-to-back ambiguity), distance by expected volume, and change in distance by Doppler shifts, you're still limited by basic physics. Of course if you're needing to distinguish up and down locations by sound alone, you can always cock your head and get quite a bit more that way.
Of course, I'm no expert in biology -- I'm more interested in sensor systems, thus my tendency to analyze human senses in those terms.
this is one component closer to my superhero costume.
You display an astounding lack of perspective. This is a home-made gizmo that runs off a 9V battery and is only a little bulkier than a fingerless glove with a cellphone stuck to it. I think that's a legitimate advance, in much the same way that the automobile was a significant progression from the steam wagon.
No kidding!!! What do you say at this point?
Yes, the human ear can distinguish vertical position as well. Ever wonder why the outer ear (the pinna) is shaped so weird? It's so it will distort sound coming from different directions differently.
Here's an demonstration I saw at the Exploratorium in San Fransisco, but you can easily reproduce this at home.
Close your eyes, and have someone standing beside you jingle a ring of keys near your ear, above, below, and adjacent. It's easy to tell where the sound is coming from.
Now bend the top cartilage over, so the shape of the ear is distorted, and repeat the previous experiment. Now the easy task of detecting direction becomes almost impossible.