Nic_3: Sound Localizing LEGO-NXTbot

The NXT-bot enthusiasts build a "sound localizing robot". It uses an RCX-Module to transform audio. (The RCX is a Lego Mindstorm component, can see it in the picture). Two microphones act as "stereo ears", that the delay between the two microphones is used, to locate the sound and point to that direction. You know that from being human. The difference is, that humans may be a little bit faster in localizing the sound, than this phase detecting bot.

The RCX samples 2 x 1000 data-points on each ear at a frequency of 36kHz. Then it processes the time-lag between both signals within 100ms. This is impressively fast, because we apply a high speed phase detection. The RCX repeats the sampling and detection process 10 times and takes the average of the measurements. Then the RCX computes the azimuth from the time-lag and sends the angle to the NXT through the HiTechnic IR-link.

There is an official blog-posting on the Nic_3 over at nxtasy, and much more technical information about this bot s given at this site.

Tags: homebrew, nxt, lego, sound, orientation, do-it-yourself
Sep_08:2008 .020200 Comments(0)

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