Research On Key Technologies Of Vision System Of Cotton-harvesting Robot

The application of cotton-picking robot will be a development trend of agriculturalmechanization and has a great prospect. Researches in cotton-picking robot have greatsignificance for reducing working intension, increasing economy efficiency and adaptingrequirement of market. The cotton-picking robot, the cotton identification andlocation technology in the natural environment is the key technology. The maturity cotton in thenatural environment was the research object. The two point in the research were as follow:In recognition of the mature cotton, the study proposed a mature cotton segmention strategybased on the YCbCr color space and Fisher discriminant analysis. First the research shoted thescene under different illumination use CCD camera, then contrasted analysis of segmentationresult in RGB,HSV, and YCbCr color space using Fisher discriminant analysis, and comparedwith proposed segmentation strategy. In order to ensure the boundaries information of the maturecotton, the research used the method of labeling to denoise. The simulation result that the cottoncould be separated exactly from background by the above algorithm whether the cotton wasexposed to the sunlight or the shadow with an accuracy of90.44%.In location of the mature cotton, the research studied the stereo vision theory, cameraimaging model and calibration theory, and used Zhang Zhengyou calibrating method to calibratethe binocular stereo vision system. The research proposed a method to determine picking points,used region-match and specific constraints to match them, accorded to the triangulation method torestore the three-dimensional coordinates. The experimental results that the method the methodcan meet the demand for cotton-picking robot vision system. Due to the key points of the SIFTalgorithm is not corners, so the research used Harris method to extract corners in segmented cottonimage, and then calculated the SIFT descriptor vector of each feature point, and finally used theSIFT matching method to match them. The experiments showed that the matching point obtainedby this method was more suitable for the restoration of the morphology of the cotton.