Orientation Technique Research Of Weed Based On Binocular Stereo Vision

In the traditional agriculture,the using way of herbicide universal is the well-distributed spraying.this method,not only improve the cost of herbicide but also damage the quality of field and pollute air. For this ,"fine agriculture",this concept is advanced in the home and abroad.According to the weed's distributing aera to spray herbicide ,in the way ,the using of herbicide is evidently reduced. Now the main research aims at recognition of weed.The insufflation system of weed cover the area of crop and weed by many spray nozzles.But the precondition is to measure position of weed.Therefore ,techniaue premise of achieving fine agricultrue is measure position of weed by the binocular vision system. To obtain the position of weed ,basing on the binocular vision system,the paper study the weed orientation technology in the static state.The main contents are:Binocular vision system that fits for measuring position of weed is builded .This system is composed of two cameras,image gather card,control platform,lens controller,decode controller and computer. The paper study pretreatment and feature extracting of weed image. For the disturbed yawp producing in the process of gathering and weighting image ,pretreatment is processed before extracting feature of weed image.Median filter mathod is used to denoise for the gathering image in the paper.and at the aspect of extracting feature of weed ,edge and corner of weed image are choosed two features. Edge feature is extracted by the Canny operators and corner feature by the ipmproving Harris operators.Camera calibration method of the binoular vision system is studied in this paper. Aiming at the distrortion of camera lens,one rank radial model is builded. According to cross ratio inbariability,distrortion coefficient is obtained .Images gathered by the camera are corrected through the coefficient ,and then a method baseing on the plane template is using to obtain inside and outside of camera . the camera calibration method is very simple and has a high precision.Stereo matching means based on weed's edge feature and corner feature is studied and the position of weed is measured in the paper.the relaxation iterative matching method is using to match the weed's edge feature .for the corner feature ,aera matching is using to make first match and compute foundation matrix through points obtained in the process of first matching,then ,according to the epilolar constraint to optimize last step reslut.on the based of inside and outside parameters of camera obtained by calibration and corresponding point's matching result,position of weed can be obtained.The paper study the weed orientation technique on the based of binocular vision system, which will provide the theoretical support and viable project for variable herbicide spraying. The results in this research are of definite instruction to development of the automatic killed-weed system based machine vision.