Ultrasonic Navigation

    Because I like bats, and I'm trying to hone my scientist to public communication skills, I am posting this project. The project is called the Modular Ultrasonic Navigation System (MUNS).  The system is designed to educate the public on bats by allowing the public to become a bat (sorta).  The system focuses on one of the more interesting aspects of a bat; navigation.  I have built six prototype modular units that produce an increasing tactile response as the user approaches on object.  The units are equipped with one ultrasonic rangefinder apiece, the rangefinder sends out a burst of ultrasonic sound waves, just like a bat.  The burst of sound bounces of an object and comes back.  Attached to the ultrasonic rangefinder is a circuit consisting of an Atmel 168 microcontroller and accompanying circuits to calculate the time between sound emission and receiving.  The time variable is then converted to a voltage output which is sent to an unbalanced motor attached to the user.  As the time between sound readings decreases, the intensity of the motor vibrating increases.  Why use tactile information?  I tried using noise but it was too much information to register all at once, you had to remember which tones were associated with which body part.

    Two units on the hands, knees, and biceps cover the “vision” an individual human would have with sight. I want participants to wear a blindfold and navigate though an unknown environment consisting of foam walls and obstacles, to find large inflatable insects hung above their heads.  Each pair of modules has a different range of scope and distance; modules connected to the hands have a very narrow scope and shorter distance to distinguish smaller obstructions, and to locate the inflatable insects.  Modules on the biceps act like peripheral vision and modules on the knees act like frontal vision, both of which are used to avoid obstacles. 

    Below are two videos, one is me (awkwardly) moving through some trees and the other is a closeup video of the left hand module in action.  In the first video I concluded that I need to extend the range of the modules, which was easy enough, I just had to change some code.  In video two I scraped the walls of the motor housing so the viewer can hear the motor rev up and slow down.

Navigating Through the Trees

Closeup of Hand Module


These pictures are closeup pics of the front and back of the modules:


Above is the prototype, I'm working on a much smaller version using surface mount components (really small electronic parts).  Below is a picture of the microcontroller setup I built to test out different ideas; this coupled with a much smaller unbalanced motor and battery should make the whole thing  less cumbersome.