Optical detection and sorting equipment design for moldy peanuts based on FPGA

Abstract. Peanut is a worldwide popular farm product with rich nutrients. However, peanut is vulnerable to Aspergillus flavus and Aspergillus niger and can be contaminated by the toxin produced by these fungi. Fungi and their toxin affect the appearance and taste of peanuts, moreover, they pose a threat to the safety of human and livestock. However, traditional detection method, sample inspection, has a variety of disadvantages, such as complexity, inefficiency and destruction. Hence, based on that the optical information of moldy peanuts is different from the healthy ones, this paper brought up a rapid and non-destructive optical detection and sorting equipment suitable for online application is necessary to separate peanuts with different qualities. This proposed equipment in this paper consisted of feeding system, lighting system, image acquisition system, rejecting system and control system. In this equipment, the core processers were Field Programmable Gate Array (FPGA) for their rapid and parallel processing capacity. After the equipment was built, three detection algorithms were purposed and tested based on this equipment and the accuracies were 75%, 80% and 82% respectively, which indicated that this equipment is feasible for the on-line detection of moldy peanuts.