Automatic weed detection and treatment in grasslands

Rumex obtusifolius is one of the most highly competitive and persistent weeds in agriculture. An automatic recognition and plant-treatment system is currently under development as an alternative treatment technique. An infrared-laser triangulation sensor combined with a high-resolution smart camera are used to generate 3D images of the weeds and their natural environment. In a segmentation process, contiguous surface patches are separated from each other. These 3D surface patches are compared with different criteria of a plant database containing surface parameters such as shape, state of surface, etc. If an object is recognized as a dock leaf, its coordinates in the vehicle coordinate system are computed and the leaves are sprayed with herbicide. The surface analysis in space can boost segmentation performance under conditions where state-of-the-art 2D recognition systems are not successful, e.g. low contrast, green-on-green images, noisy images, or images taken from inappropriate positions. Initial results have been promising. System development focuses on a more robust imaging-sensor technique and refinement of the different algorithms. Looking to the future, the system design allows the flexible integration of other plant species.