In this paper, we proposed a new algorithm of the guidance line extraction for autonomousweeding robot based on infrared vision sensor in wet paddy. It is the critical process for guidance lineextraction which finds the central point or area of rice row. In order to improve accuracy of the guidanceline, we are trying to use the morphological characteristics of rice that the direction of rice leaves haveconvergence to central area of rice row. Using Hough transform, we were represented the curved leavesas a combination of segmented straight lines on binary image that has been skeletonized and segmentedobject. A slope of the guidance line was gotten as calculate the average slope of all segmented lines. Aninitial point of the guidance line was determined that is the maximum pixel value of the accumulatedwhite columns of a binary image which is rotated the slope of guidance line in the opposite direction.
We also have verified an accuracy of the proposed algorithm by experiments in the real wet paddy.