This week, I worked with my team in assembling the conveyor belt and also worked on the pixel classification algorithm.
As for working on the conveyor belt, I suggested a final model we could use in order to be able to meet the requirements we have and determined its feasibility. For now, we plan on using channels to lodge the conveyor belt so that it’s at a height good enough such that the leather belt that goes around it wouldn’t have any friction with the wood. We still need to work this out. I also worked with CAD to help 3D print the parts.
For the pixel classification, I tested it on a dataset and kept modifying the threshold to see what optimal value would work. A threshold of 20% rottenness seems to be the best for separating the good bananas from the rotten ones. I examined the results of the classification and less than 0.8% are misclassified for the rotten bananas out of a sample of 1100+ images of rotten bananas and only around 2% of the good bananas were misclassified out of a sample of around 800 images of good bananas, which meets are benchmarks. The misclassified images were primarily ones where the background was yellow or brown, as a result contributing towards the misclassification. However, we’ll be having a plain black or plain white background for our fruits so that should meet our purposes. I tried using edge detection to first segment out the bananas before running the image segmentation, but using edge detection didn’t help much since for those images the edges weren’t detected well enough to form a good mask. I’ll be testing the algorithm on another test dataset and then we plan on transitioning to testing on real bananas. I’m looking into the AlexNet classification, but I doubt we would need to use it since our classification algorithm seems to be giving wonderful results.
We seem to be on track with respect to our schedule. As for the next few days, I plan on looking into AlexNet and implementing a very basic algorithm just to see its classification results, though I doubt we’d need that, so I plan on focusing my efforts more towards getting the conveyor belt setup done. We must also click pictures of actual bananas for testing and we should have the live feed working with the camera in the next few days. Post that, we should start looking into building the gate and automating its rotation.