Automatic Walnut Sorting System Based on Adaptive Fuzzy Control

Walnut has rich nutritional value, but the nutrient content of each walnut is different, in order to distinguish them and improve the product value. In this paper, the spectrogram of walnut wavelength and absorbance was obtained by near infrared spectroscopy, and compared with the spectrogram of standard sample. The content of walnut was judged and graded. Then, the motor on the pipeline was controlled by PLC, and the sorted walnut was sent into the storage box to realize the automatic separation of walnut. By using the arithmetic structure of fuzzy control plus PID to control the running speed of pipeline, the sorting system can run fast and steadily. The results showed that walnuts were classified as unqualified walnuts below 0.5, third-class walnuts below 0.5-0.7, second-class walnuts from 0.7-0.85, first-class walnuts from 0.85-1.0 and first-class walnuts above 1.0 by the total absorption rate of protein and fat. The detection accuracy of all walnuts reached more than 95%. This method can easily distinguish walnuts at different levels and has high accuracy.