基于垄线平行特征的视觉导航多垄线识别

为有效快速地识别农田多条垄线以实现农业机器人视觉导航与定位，提出一种基于机器视觉的田间多垄线识别与定位方法。使用VC++ 6.0开发了农业机器人视觉导航定位图像处理软件。该方法通过图像预处理获得各垄行所在区域，使用垂直投影法提取出导航定位点。根据摄像机标定原理与透视变换原理，计算出各导航定位点世界坐标。然后结合垄线基本平行的特征，使用改进的基于Hough变换的农田多垄线识别算法，实现多垄线的识别与定位。使用多幅农田图像进行试验并在室内进行了模拟试验。处理一幅320×240的农田图像约耗时219.4 ms，室内试验各垄线导航距与导航角的平均误差分别为2.33 mm与0.3°。结果表明，该方法能有效识别与定位农田的多条垄线，同时算法的实时性也能满足 要求。

Crop rows detection based on parallel characteristic of crop rows using visual navigation

To detect and localize the crop rows quickly and effectively for navigation of agricultural machines, a new algorithm for crop rows detection is proposed in this paper. A navigation software was developed in VC++ 6.0. Crop rows were separated from soil background by image pre-processing, and the localization points were got by vertical projection. The world coordinates of each localization point were computed according to the principle of perspective transformation and the camera calibration results. With the parallel characteristic of crop rows, an improved algorithm based on Hough Transform was employed for the detection and localization of crop rows. The experiment with images of crop rows and the simulation experiment in laboratory showed that the new algorithm took 219.4 ms to process a 320×240 pixels color image, and the average errors of navigation distance and navigation angle were 2.33 mm and 0.3°. The experimental results confirmed that the algorithm was accurate, effective and fast enough to detect and localize crop rows for real-time navigation.