Researches On The Control System For A High-efficient Weeding Robot

Weeds compete with crops for water, nutrients and sunlight, reducing crop yields. Sprayingherbicides has been the most commonly treatment to weeds, but large amount use of herbicideswill not only result in a waste of herbicides, but also cause environment pollution. Recently,weeding robots have been extensively researched. In this paper, a control system ofhigh-efficient weeding robot is proposed aiming at weeding simulataneouly both in intro-rowand inter-row, including navigation control system, weed detection and weeding control system.In this paper the camera firstly captured plenty images of the crops in seedling stage, andthen analysed the RGB characteristics of the images, used Extra-green method to grayscaleimage, and used Ostu method to obtain binary images, and used median filtering and areafiltering method for filtering and reducing noise, last realized the segmentation between greenplants and soil background. Then according to the characteristics of the crop lines,algorithm of navigation based on the Hough transform was studied, the reliability ofthe algorithm was proved through analyzing different images of the crop line. Then calibratedthe camara and acquired the internal and external parameters of the camara to enhance theaccuracy of the navigation informations.Secondly, this paper studied the motion control system of the weeding robot and designedthe navigation control system platform combined with the navigation algorithm by using themulti-threading method based on VC++. In the laboratory environment, the accuracy, stabilityand real-time performances were verified on both VoyagerII robot and the weeding robotdeveloped by our team. The robots were able to recongnize the navigation path correctly andwalk independently.Then the method of intra-row weed detection based on the correlation type infrared sensorwas proposed，combined MCS-51microcontroller with PC, the weed detection circuit wasdesigned. Based on MCS-51MCU, this paper developed the software and the hardware systemsof weeding control system, specifically including the intra-row weeding control system torealize intra-row weeding control, and the inter-row weeding control system by using PWMprinciple to realize inter-row weeding control.