Controlling weeds in agriculture is a big problem that farmers face worldwide. Weeds compete with crops for sources reminiscent of daylight, water, and vitamins, resulting in diminished 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 line 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 considerations.
One of many major strategies employed to manage weeds is using herbicides. Herbicides are chemical substances particularly designed to kill or inhibit the expansion of undesirable crops. They’re extensively used as a result of their effectiveness in weed management. Herbicides work by concentrating on particular physiological processes in crops, reminiscent of photosynthesis or cell division, resulting in the loss of life of the weeds, with out impacting the crops.
Whereas herbicides have been efficient instruments in weed administration, there are considerations related to their use. Environmental issues are one of many key elements driving the exploration of other weed management strategies. Herbicides can persist within the surroundings, doubtlessly resulting in water contamination and detrimental results on non-target organisms, together with helpful 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 not too long ago constructed a weed-destroying robotic that presents one other potential path ahead. Whereas it is probably not sensible for all conditions, it seems to be like it might be plenty of enjoyable to construct, and it appears to be working simply effective for NathanBuildsDIY’s backyard. His robotic leverages pc 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 way of the lens will be centered on a small space of the bottom. A Raspberry Pi single-board pc controls the robotic, and a Raspberry Pi digicam is used to seize photos of the surroundings.
To find weeds, the digicam 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 nicely for small weeds with the digicam two ft above the bottom, so NathanBuildsDIY collected his personal dataset from his backyard to coach the mannequin. Pictures had been break up up right into a grid of squares in order that weeds could possibly 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 might be separated by cardboard dividers. This info helps align the arm such that the solar is shining by way of the lens. Subsequent, a effective alignment course of is triggered. Usually, a canopy is positioned over the lens in order that it doesn’t burn the whole lot in its path — however it does have just a few holes in it to assist with concentrating on. This gentle is used to line the main target of the lens up precisely with the sq. through which the weed is situated.
Lastly, the quilt is lifted off from the lens, and the linear actuator adjusts the peak of the arm to make sure it’s tightly centered on the goal. The arm then strikes about your entire sq. scorching the whole lot 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 max security earlier than it rolls on to the subsequent space in want of remedy.
Talking of security — along with burning weeds, the lens is sort of able to setting absolutely anything flammable on fireplace, 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 that you could control it, simply in case of an issue.
After going by way of the event course of, NathanBuildsDIY realized that there are some areas that could possibly be improved to create a extra refined model of the robotic. First, the body is unnecessarily giant — reducing down on that bulk may enable for using smaller, inexpensive parts, and would additionally assist the robotic to suit into tighter areas. Additionally, changing the wheels with tank treads would assist in traversing tough terrain. NathanBuildsDIY additionally notes that ideally, the algorithm ought to find the middle of a weed and deal with that somewhat than burning a bigger space, which may additionally unintentionally destroy crops.
