Hacker News Reader

Comment by mattlondon | Hacker News Reader

Just out of curiosity, most ploughing tractors appear go quite slow.

Is there any reason why they cannot be geared as required to plough at 50/60/70mph etc? Is there something about the actual physics of ploughing/whatever/etc that requires slowness? Or is it more the fact that it is physically very arduous for the machine and it would cost too much for both the power required and speed?

Just kinda thinking along the Elon Musk line of thought around robots in a car factory - i.e. why aren't they moving so fast that all we see is a blur etc

View on HN

Partly it's about friction and grip - ploughs are dragged through the ground at depths up to 30cm, turning the soil through 180°. The power required to do that is considerable but most critically the grip the power unit (wheeled or tracked tractor, animals) has controls speed, which depends on the conditions. In addition, as speeds increase the soil will not move smoothly over the mould-board and thus not leave a consistent result ready for the next operation.

Efficiency is always a consideration. There's an interesting "Mega Factories" video where they cover the Porsche factory in Leipzig that builds the Macan and Panamera [1], in which a supervisor points out that the robot arms accelerate only as quickly as they need to. They were able to trim something like 10% of the robots' energy usage just by controlling movement speed and acceleration. There are hundreds of massive robots in the factory shifting heavy objects around, so this isn't a trivial savings.

Another consideration is that a 70 MPH tractor would stir up way too much dust. Topsoil would end up everywhere except where it's wanted.

One valid question might be why a robotic tractor needs to be shaped like a human-driven tractor, or work like one. Maybe it'd be more effective to use an army of small drone-like machines that operate closer to the ground?

1: https://www.youtube.com/watch?v=F3FUH9fVC_M

Reply on news.ycombinator.com