Ag is hard. It’s dusty. The weather can be brutal. Stuff gets left out year round. The turnover is high. Schedules are dynamic and unforgiving (when the weather turns, you have to adapt your whole operation). There’s not a lot of highly technical staff to maintain things; bailing wire and bandaids is a real thing. The tradition of “hacking things” to keep them working comes from farmers.
The more complicated your machinery, the more your MTBF product goes up. So complicated units don’t scale well.
If a single sprinkler on a pivot fails or misbehaves, there’s nearly 400 of them and there’s some overlap. If your “robot” stalls out with some grit or a power supply issue or a bricked update, or leaky hydraulics, you just lost 1/10 of your pivot. Pray it happens on an inner span, rather than an outer one.
It’s interesting to note how the size of Meganeura is credited to environmental factors (oxygen ration in the air). Context is everything, as usual.
Well, toxic chemical agents can also be used as weapon on human civil, and — sadly — it was actually used that way. Plus even when you use them for farming, you still have pollution that will erode biodiversity, human health, and other sustainable environment negative impacts.
Not to say that robot swarm is necessarily a perfect green solution. You still have to build them and feed them with energy, so even if the robot would be exempt of undesirable side effect on local operational site, the global impact would most likely include plants in their lifecycle.
In Europe, taking the train is often more expensive than flying.
Sadly it's not fashionable because it isn't cheaper and takes a lot longer.
In the US, most tracks prioritize freight traffic over passenger rail. And there is a tremendous amount of freight traffic. There may not often be traffic jams, but when you are diverted to side track to wait and allow a priority freight train through, it's not uncommon to wait a very long time (I've been delayed more than an hour on the 3 hour train ride from Portland to Seattle).
There are also huge bottlenecks in US track infrastructure that absolutely do lead to traffic jams - perhaps most infamously in New York City. Vetoing the addition of 6 additional tracks through NYC is one of the reason Chris Christie was so hated.
https://www.amtrak.com/privately-owned-rail-cars
There was even some hn post on it where someone detailed how much it costs and what you get
As your arm gets longer, it has to get stronger, thus heavier, thus requiring larger motors, and anchored to the ground better. After a handful of meters, robot arms can’t hold themselves up, let alone carry a useful tool.
There are multiple meter long robot arms for lifting big things in factories but they are enormous, enormously expensive, and consume enormous power.
But here’s a delightful concept that sidesteps this, by making the arm weigh nothing:
I work in this industry (contributing architect of https://nelsonirrigation.com/products/twig-wireless-controls...).
We dream of lots of fun things. And even try some of them. But not a few days go by that we don’t once again mutter “power is king” To each other. Everything we do revolves around the constraint of power budgets.
Make a square of tensioned cable (or rigid rail) boxing in some area of garden/food forest/farmland at a height above the plants. Have 4 modules which maintain position on opposite sides and holds a tensioned wire between them, making a tensioned wire along the x and a tensioned wire along the y. At the intersection of these wires there is a powered doohicky that can act like a spider and drop down onto the plants below and do its work. The power to the doohicky could be cable from either axis.
Following the other comment re: power being king, what if we used a hub-and-spoke model where small drones with cameras (for sensing) and simple arms w/ clampers (for manipulating) perform 'bursts' of energy intensive activity and aggregate their sensory inputs into one composite report on the health of the plants? They do their thing (maybe for 10 - 15 mins or however long their battery lasts) and then fly back to the hub to charge. The hub itself could rely on a hybrid combo of guaranteed external power and solar panels.
Ofc, it'd be cool to see a cost analysis of how expensive this solution is (from both technical and financial standpoints) versus simpler, more energy-efficient human inputs (aka walk around your garden and prune trees that need it and pick berries that are ripe).
This technology has existed for a long time now (see cable robots, or cable-suspended cameras)
My better half owns a small hotel with 19 rooms. Turns out running a simple 10 minutes task in each room takes... entire day (3 hours for the work + switch room overhead + breaks turns out to be full day often).
A key problem with small autonomous robots is their energy supply and mass. Batteries have low energy density. Actuators have bad power to weight ratios too. Living things are enormously more efficient. So much so that the intuition apparently offered by watching animals usually does not apply.
This is extremely true for swarm robotics, inspired by ants, termites, etc. Swarm critters rely on the emergent effects of lots of behavior to make up for their limited sensing and computation. By 'limited' I mean relative to a mammal or bird. Lots of behavior means lots of energy spent moving and doing: exactly what is prohibitively expensive for a robot.
Computation and sensing is getting better, smaller and cheaper much faster than batteries and actuators. This trend favors smarter robots that think carefully (cheap) and do the right thing (expensive per shot).