An automated inspection station for machine-vision grading of potatoes

A prototype inspection station based on the United States Department of Agriculture (USDA) inspection standards was developed for potato grading. The station consisted of an imaging chamber, conveyor, camera, sorting unit, and personal computer for image acquisition, analysis, and equipment control. A sample of 9.1 kg (20 1b) of pregraded potatoes were evaluated in three separate experimental runs to assess the system performance. The system correctly classified 80%, 77%, and 88% of the moving potatoes in the three runs at 3 potatoes/min, and 98%, 97%, and 97%, in three runs of stationary potatoes. Shape analysis was adversely affected by the potato motion, and this contributed to the misclassification error.