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Comment by robotresearcher | Hacker News Reader

> the future is swarms of small robots

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).

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This is spot on.

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.

So... we engineer the plants to grow bigger to accommodate for robots that cannot be made smaller, or with denser battery packs :D

Here's an idea, curious for some feedback:

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.

It feels like this approach would constrain you from planting in an organic/spontaneous manner; you'd have to plant stuff to make sure it lines up with the cables above right?

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).

The solution that the commenter above would give a full 2-dimensional range to the robot across the whole field.

This technology has existed for a long time now (see cable robots, or cable-suspended cameras)

How about having an induction recharge state every few meters? They could be rolled out as the same type of infrastructure as water piping is now. At scale, induction chargers can be manufactured very inexpensively.

Why ? You can just have one big tractor hauling a bunch of them. What does spreading it to smaller agents gain you ?

Plus maintenance on large number of things is a b*tch.

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).

The problem is that swarms of robots can be used for destructive purposes. There, the amount of energy expended and the loss of some drones is no match for the destruction caused. Not to mention all those decentralized self healing swarms are totally resistant to the conventional “destroy the Borg queen” nonsense trope of so many alien movies. (Yes I specifically mentioned the Borg queen because it was the moment Trek nerfed the Borg’s greatest strength and became like all the other denoument alien action flick franchises)

>The problem is that swarms of robots can be used for destructive purposes.

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.

Not to mention by making it pulled by tractor you get something that complements the existing o̶l̶i̶g̶o̶p̶o̶l̶i̶s̶t̶s̶ large players so it's more like you can do something with them to scale yourself out rather than compete against them to scale yourself out. It's much smarter making something tractor pulled from a business economics perspective, not just from a physics perspective.

what if we make them bigger than insects but still relatively small? just an arm on a track. heck, we can put the energy in the track too. boom, no battery.

There are some interesting things being done with pivot spans. Hummingbird runs nozzles back and forth on rails suspended from each pivot span. But they’re difficult to keep running.

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.

I think you meant the MTBF goes down.

Meganeura is an insect too, so most civil drones are already smaller than biggest insects.

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.

https://en.wikipedia.org/wiki/Meganeura

Yeah, instead of a swarm you could have one gigantic arm that can reach anywhere.

Gigantic arms are not feasible because of how torque and leverage work.

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:

https://youtu.be/INTHRNcyW9w

This could simultaneously absolve the need for autonomous vehicles, because whenever you need to go somewhere, you could just make the giant arm put you there.

That's called a train. It's great. You can read a book while you are transported, it uses very little power to get you there, it can be 0 emission, there are no traffic jams. Sadly it's not fashionable cause you can't show off how wealthy you are by using it.

Sure you can

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

Why not both? You could have each train actually be an array of arms that reach out and pick people up and move them along their route. The arms wouldn't have to be as long since the train is moving along the rail, and a select number of arms could be reserved for first class passengers.

> There are no traffic jams

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.

I occasionally take the train because I like the atmosphere.

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.

That's because trains get taxed, while flights _still_ get subsidised. It's maddening.

It's faster than flights on short (<3 hour) routes because you don't have the whole security theatre thing. Also train stations are in the city center usually and airports are in the outskirts.

On more actual security concerns side, you will have a hard time hijacking a train and jet into the side of a skyscraper.

The far more common scenario - a bomb in a bag - is very devastating in closed spaces such as trains and buses.

Nobody does it in trains/buses, cause it's much more efficient to do it at the train/bus station. Or any other place where people queue.

It's happened dozens of times in my country - I've lost schoolmates (not personal friends) in bus bombings.

First class wagons are used exactly for that, to show the wealth.

Not really. I often take 1st class because 2nd class is full and I'd have to stand for 2 hours and the difference is 5-10 USD.

Just piggyback off of center-pivot irrigation arms. Attach little arms to it that destroy weeds and apply pesticides

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