A Method for Identification and Matching of the Picking Point for Mature Litchi under Structural Environment

Abstract

A method to identify the picking point of the whole mature litchi fruit and its matching method based on binocular stereo vision under the structural environment is proposed in this paper. The mature litchi clusters in the extracted image were segmented by using the improved K-means clustering algorithm. The region of interest (ROI) of the Litchi stems is set based on the characteristics of the center of the litchi fruit region and the minimum circumscribed rectangle. Corner extraction from the main fruit bearing branch of litchi was carried out by Harris algorithm. The customized function of circle distance is used to determine the optimal corner, and then cumulative probability Hough linear detection of the Litchi stems is used to determine the straight line of the picking point. Finally, the two-dimensional pixel coordinates of the picking point are determined. Then the three-dimensional coordinates of litchi picking points are obtained by SGBM stereo matching algorithm. The experimental results show that the matching success rate of picking points can reach 86.63%. It provides the foundation for litchi harvesting robot to pick litchi fruit successful.