As part of the AgBot competition I have begun analyzing watermelons to correlate their impulse response to ripeness. This project is still in the early stages but according to the grocery store, watermellon farmers, and the internet; humans are able to determine ripeness by ear alone. Simply tap a watermelon lightly with one finger and listen for a deep hollow sound. While I’ve already found a couple of phone apps that can do this their results are… shaky at best.
First step was to build a microphone since I couldn’t find one in the lab. When we get into the more serious data taking I’ll probably go ask to borrow a really good microphone and a sound-stage from my old theater.
Samples taken from the miraculously working microphone
Plot of the cepstrum after noise reduction
Plot of the fourier transform after some noise reduction
Zachary Eagan 