Controlling weeds in agriculture is a major problem that farmers face worldwide. Weeds compete with crops for assets resembling daylight, water, and vitamins, resulting in lowered crop yields and high quality. The scope of the weed downside 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 may 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 using herbicides. Herbicides are chemical substances particularly designed to kill or inhibit the expansion of undesirable crops. They’re extensively used resulting from their effectiveness in weed management. Herbicides work by focusing on particular physiological processes in crops, resembling 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 issues related to their use. Environmental issues are one of many key components driving the exploration of different weed management strategies. Herbicides can persist within the atmosphere, probably resulting in water contamination and detrimental results on non-target organisms, together with useful bugs, birds, and aquatic life. There may be 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 potential path ahead. Whereas it might not be sensible for all conditions, it appears like it will be a whole lot of enjoyable to construct, and it appears to be working simply high-quality for NathanBuildsDIY’s backyard. His robotic leverages pc imaginative and prescient and machine studying to drive round and scout out weeds. When they’re positioned, 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 supplied 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 via the lens may be targeted on a small space of the bottom. A Raspberry Pi single-board pc controls the robotic, and a Raspberry Pi digital camera is used to seize pictures of the atmosphere.
To find weeds, the digital camera captures a stream of pictures and feeds them right into a MobileNet neural community for detection. Retraining the mannequin with present 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 had been cut up up right into a grid of squares in order that weeds might 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 are separated by cardboard dividers. This data helps align the arm such that the solar is shining via the lens. Subsequent, a high-quality alignment course of is triggered. Usually, a canopy is positioned over the lens in order that it doesn’t burn every thing in its path — however it does have a number of holes in it to assist with focusing on. This mild is used to line the main focus of the lens up precisely with the sq. through which the weed is positioned.
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 complete sq. scorching every thing 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 following space in want of remedy.
Talking of security — along with burning weeds, the lens is kind 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 with the intention to keep watch over it, simply in case of an issue.
After going via the event course of, NathanBuildsDIY realized that there are some areas that might be improved to create a extra refined model of the robotic. First, the body is unnecessarily giant — slicing down on that bulk may enable for using smaller, cheaper parts, 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 deal with that slightly than burning a bigger space, which may additionally unintentionally destroy crops.
