Small Robot Company have a robot called Dick which uses "Non-Chemical Weeding", i.e. they zap the weed to kill it, and it's root. They use other small robots to do the mapping and planting. I really like the idea of small, specialised robots for different tasks.
The text "to take place in early 2020" and "AVAILABLE 2021" on that site, in November 2022, does not inspire confidence.
I guess in the near term dozens of specialized robots for each task will be necessary, but the idea I like is teams of general purpose robots using simple tools to perform almost any task "manually". It's too early to implement that now, but I think it will be feasible within my lifetime.
Generality is probably one reason why this robot sprays instead of hoeing. In addition to killing weeds, by changing chemicals this thing can fertilize, and they also mention pollinating and preventing pollination of flowers. (Preventing pollination avoids overburdening some kinds of trees. Currently instead people have to do "thinning" which is simply pulling half of the crop off the tree before it's ripe and throwing it on the ground).
Weed zapping is fascinating - but putting the kind of power electronics required to deliver sufficient voltage in a mobile robot is terrifying from an OHSA perspective.
One group I'm familiar with are using 50kv (and "more than enough" amps) for the purpose.
It's not really. Plenty of people have handheld tasers powered by 9v batteries and plenty of farm equipment can (and does) mangle people not being careful around very dangerous machines.
This is just a misunderstanding of the risks involved in various things.
Yeah there are tons of really dangerous things on farms, like Paraquat, or power take-offs. Power doesn't have to be electrical to kill you. Mechanical power will do the job just fine.
I'm well aware that it's far from the only thing that'll kill me on a farm.
That said, comparing a 50Kv shock to a handheld taser (which typically run at 300-500v) makes me think I might not be the one who misunderstands the risks.
You're off by three orders of magnitude. You need about 32 million volts per meter to overcome the resistance of the air. For a gap of a centimeter, it's about a few hundred kilovolts.
And I grew up farming, I'm quite familiar with the dangers.
For example harvesting equipment... the big ones are sort of up to a 30 food wide chainsaw with conveyors and other grabby bits to suck you in. People need to be many meters away from those things while they're running for any sense of safety. A hot spark has nothing on many other dangers and if designed with any sense would only result in severe local burns. Plenty of farm equipment will effortlessly rip a limb off if it doesn't tear your entire body into bite sized chunks.
You know the machines that do that and you don't go near them. When you're the operator you must know where everyone is at all times and know what they mean to do... and be able to communicate with them with a series of gestures, eye contact, short yells, etc. If you don't it's trivially easy to kill your helpers.
Maybe this is a false equivalence, but I think industrial scale leaching of poisons into the water supply is more terrifying and anything that can replace that is worth looking into.
https://www.smallrobotcompany.com/weed-killing