Grading, sorting, and classification of agricultural products are important steps to ensure a profitable and sustainable food industry. Human-intensive labors are replaced with better devices/machines that can be used in-line and generate sufficiently fast measurements for a high production volume. Most previous works focused on only one of the external quality parameters, such as color, size, mass, shape, and defects. In this work, we proposed an integrated machine vision system that can grade, sort, and classify mangoes using multiple features including weight, size, and external defects. We found that weight estimation using our proposed algorithm based on visual information was not statistically different from that of a conventional weight measurement using a static digital load cell; the estimation error is relatively small (4–5%). We also constructed an artificial neural network model to classify mango having multiple types of external defect; the classification error is less than 8% for the worst possible case. The results indicate that our system shows a great potential to be used in a real industrial setting. Future work will aim to investigate other features such as ripeness and bruises to increase the effectiveness and practicality of the system.
Part of the book: Agricultural Robots