While manually hoeing weeds out of crops can be very time- and labor-intensive, spraying those crops with herbicides is definitely not eco-friendly. A German consortium is developing a third choice, in the form of the AMU-Bot weed-killing robot.
Moving along on caterpillar-type treads, the bot is capable of autonomously travelling up and down the rows of plants in orchards, vegetable fields or tree nurseries. It utilizes onboard LiDAR scanners to stay between those rows, and to see where each row ends so it can turn around and head down the next one.
And although the AMU-Bot isn't capable of identifying specific types of plants, it is able to differentiate between crop plants and others which shouldn't be there – weeds, in other words. When one of the latter is spotted, the robot lowers down a rotary harrow (kind of like a toothed version of the reel on a push-lawnmower) which churns up the soil and uproots the offending plant.
For tackling weeds that are growing between the rows, the harrow is simply deployed right in front of the robot as it moves forward. On the other hand, if a weed is spotted growing between crop plants within a row alongside the robot, the machine stops and moves its harrow sideways into the gap.
The AMU-Bot project is funded by the German Federal Office of Agriculture and Food, and is being coordinated by the Fraunhofer Institute for Manufacturing Engineering and Automation (which also designed the height-adjustable rotary harrow). Bosch is developing the navigation and sensory system, and agricultural robotics company KommTek is responsible for the caterpillar drive system.
There's currently no word on when the AMU-Bot may enter service. It could face some competition, though, as other groups are developing robots that use lasers and electrical pulses to kill weeds.
Source: Fraunhofer
