Controlling weeds in agriculture is a major problem that farmers face worldwide. Weeds compete with crops for sources akin to daylight, water, and vitamins, resulting in lowered crop yields and high quality. The scope of the weed drawback is huge, as weeds can infest fields, orchards, and vineyards, negatively impacting agricultural productiveness. In accordance with estimates by the Meals and Agriculture Group, weeds could cause as much as 34% yield losses in main crops, resulting in substantial financial losses and meals safety issues.
One of many main strategies employed to regulate weeds is the usage of herbicides. Herbicides are chemical substances particularly designed to kill or inhibit the expansion of undesirable crops. They’re broadly used as a consequence of their effectiveness in weed management. Herbicides work by focusing on particular physiological processes in crops, akin to photosynthesis or cell division, resulting in the demise of the weeds, with out impacting the crops.
Whereas herbicides have been efficient instruments in weed administration, there are issues related to their use. Environmental concerns are one of many key components driving the exploration of different weed management strategies. Herbicides can persist within the surroundings, doubtlessly resulting in water contamination and detrimental results on non-target organisms, together with useful bugs, birds, and aquatic life. There’s additionally the chance of herbicide resistance improvement amongst weeds, rendering sure herbicides ineffective over time.
Locking on to the goal (📷: NathanBuildsDIY)
YouTuber NathanBuildsDIY just lately constructed a weed-destroying robotic that presents one other doable path ahead. Whereas it is probably not sensible for all conditions, it seems to be like it will be a variety of enjoyable to construct, and it appears to be working simply superb for NathanBuildsDIY’s backyard. His robotic leverages laptop imaginative and prescient and machine studying to drive round and scout out weeds. When they’re situated, a lens focuses the solar’s rays on the weed to burn it into oblivion.
The body of the robotic is constructed of wooden, with a pair of bicycle wheel frames and a pair of garden mower wheels pushed by electrical motors. A movable arm is provided with a Fresnel lens to focus daylight on weeds as wanted. A linear actuator strikes the arm up and down such that the sunshine passing by the lens could be targeted on a small space of the bottom. A Raspberry Pi single-board laptop controls the robotic, and a Raspberry Pi digital camera is used to seize photos of the surroundings.
To find weeds, the digital camera captures a stream of photos and feeds them right into a MobileNet neural community for detection. Retraining the mannequin with current weed datasets didn’t work properly for small weeds with the digital camera two ft above the bottom, so NathanBuildsDIY collected his personal dataset from his backyard to coach the mannequin. Photographs have been cut up up right into a grid of squares in order that weeds may very well be extra exactly localized.
That is gonna go away a mark (📷: NathanBuildsDIY)
When a weed is discovered, the robotic’s arm swings into motion — first a tough calibration course of is initiated. This course of makes use of 4 photoresistors, pointing upwards, which can be separated by cardboard dividers. This info helps align the arm such that the solar is shining by the lens. Subsequent, a superb alignment course of is triggered. Usually, a canopy is positioned over the lens in order that it doesn’t burn all the pieces in its path — but it surely does have a couple of holes in it to assist with focusing on. This mild is used to line the main target of the lens up precisely with the sq. wherein the weed is situated.
Lastly, the duvet is lifted off from the lens, and the linear actuator adjusts the peak of the arm to make sure it’s tightly targeted on the goal. The arm then strikes about the whole sq. scorching all the pieces in its path. After the job is completed, the lens cowl strikes again into place, and the linear actuator drops the arm down nearer to the bottom to take it out of focus for optimum security earlier than it rolls on to the following space in want of remedy.
Talking of security — along with burning weeds, the lens is sort of able to setting absolutely anything flammable on hearth, like leaves, mulch, or dry grass, so one must be cautious utilizing a robotic like this. NathanBuildsDIY recommends remaining within the space whereas the robotic works so as to keep watch over it, simply in case of an issue.
After going by the event course of, NathanBuildsDIY realized that there are some areas that may very well be improved to create a extra refined model of the robotic. First, the body is unnecessarily massive — chopping down on that bulk may permit for the usage of smaller, inexpensive elements, and would additionally assist the robotic to suit into tighter areas. Additionally, changing the wheels with tank treads would assist in traversing troublesome terrain. NathanBuildsDIY additionally notes that ideally, the algorithm ought to find the middle of a weed and give attention to that reasonably than burning a bigger space, which may additionally unintentionally destroy crops.
