Battling weeds can be expensive, labor intensive and use large amounts of chemicals. To help make this easier [NathanBuilds] has developed V2 of his open-source drone weed spraying system, complete with automated battery swaps, herbicide refills, and an AI vision system for weed identification.
The drone has a 3D printed frame, doubling as a chemical reservoir. V1 used a off-the-shelf frame, with separate tank. Surprisingly, it doesn’t look like [Nathan] had issues with leaks between the layer lines. For autonomous missions, it uses ArduPilot running on a PixHawk, coupled with RTK GPS for cm-level accuracy and a LiDAR altimeter. [Nathan] demonstrated the system in a field where he is trying to eradicate invasive blackberry bushes while minimizing the effect on the native prairie grass. He uses a custom image classification model running on a Raspberry Pi Zero, which only switches on the sprayers when it sees blackberry bushes in the frame. The Raspberry Pi Global Shutter camera is used to get blur-free images.
At just 305×305 mm (1×1 ft), the drone has limited herbicide capacity, and we expect the flights to be fairly short. For the automated pit stops, the drone lands on a 6×8 ft pad, where a motorized capture system pulls the drone into the reload bay. Here a linear actuator pushes a new battery into the side of the drone while pushing the spend battery one out the other side. The battery unit is a normal LiPo battery in 3D-printed frame. The terminal are connected to copper wire and tape contacts on the outside the battery unit, which connect to matching contacts in the drone and charging receptacles. This means the battery can easily short if it touches a metal surface, but a minor redesign could solve this quickly. There are revolving receptacles on either side of the reload bay, which immediately start charging the battery when ejected from the drone.
Developing a fully integrated system like this is no small task, and it shows a lot of potential. It might look a little rough around the edges, but [Nathan] has released all the design files and detailed video tutorials for all the subsystems, so it’s ready for refinement.
He can send the blackberry bushes to me! Yummy!
Ayo, my last startup company is doing similar on a mega scale for farms. Check out Guardian Agriculture (guardian.ag). That drone is the size of a van…
About this big?
https://www.homemadetools.net/forum/farmer-takes-down-drone-gif-103406
One of my favorite things to do is to ask people for the definition of a weed. Because any definition they’ll give you will cover things that they definitely do not consider weeds. There is no such thing as a weed, just plants that grow well. And we know from all of our modern regenerative and permaculture research that mono cropping has devastated the environment and slowly degrades farms over time.
It certainly harder to harvest polyculture plots, but they are just so much more efficient and helps increase the biodiversity. My hope is that technology will be used to help farmers harvest polyculture crops, especially many of those considered weeds that are perfectly edible. For example, there’s a plants in Florida that many consider a weed, Spanish needles aka biden’s alba, That’s around a third most important pollinator plant in the state, was eaten by the indigenous Americans, and grows year-round with no effort whatsoever. It’s like unlimited free food, but all of my neighbors kill it, which is madness.
Also, though it’s an extremely advanced technique, the best farmers I know understand the soil types that different plants that you’re probably calling weeds grow best in and they use the presence of those plants as indicators of the soil nutrition. So the plants can literally give farmers extra information about their land, and yet people want to spray them and remove that extra information.
I admire the skills used in this project and I hope that in the future it transitions away from chemicals of death such as herbicides and instead transition to spraying nutrients that are in part determined by those previously killed plants.