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Terrible title. A leaf blower does that. The abstract isn't great either. Can someone describe the actual contribution of this paper in a sentence?

I'm not sure what the contribution is since it seems like just engineering, but pretty cool low-tech control system engineering. They made a thing that can automatically push an object along an arbitrary path on the ground by pointing (in 2 axes) a jet of air at the ground behind it, controlled by feedback of the object's position. It doesn't seem to say anything about how the feedback was done so I guess machine vision which is its whole own problem.

If I read this right - They can also change to pulling objects towards the leafblower by varying its orientation without its position.

Yes, but you can do that with a leaf blower too. Maybe their jet is a little special to extend the range of "tractor beaming" but the don't say much about that either.

> A leaf blower does that.

A leaf blower in the hand of a human can do that. Without the human pointing the leafblower just right the objects will go in random directions.

They made a controller to control their “leafblower”[1] just right so the objects end up in where they want them to, and then they described how well it works on various tasks. This automated controller is their contribution.

1: They didn’t use an actual leafblower but a nozzle attached to an air compressor.

> A leaf blower in the hand of a human can do that.

In twenty years of leaf blowing I have never managed to move a small light object in a 'S' shape as per [0] or drag a hand saw as per [1]

[0] https://onlinelibrary.wiley.com/doi/10.1002/aisy.202400174 / aisy202400174-sup-0001-SuppData-S5.mp4

[1] https://onlinelibrary.wiley.com/doi/10.1002/aisy.202400174 / aisy202400174-sup-0001-SuppData-S8.mp4

As I wrote it is not really a leafblower. The jet is much more concentrated.

> I have never managed to move a small light object in a 'S' shape

Me neither. But I have moved around objects with a water jet (when messing around with a garden hose). Never had an air jet fast and powerful enough to do the trick so that's the closest analogy I have. It's not that hard? Never tried an S shape but the basic theory with the water hose is that you aim at a point you want to move the object away from. So if you want to move something towards A you aim the hose the point opposite of A. And then you feel out how close you need to move the aim point to the object to start it moving at the right pace but far enough to keep it controlled. The controller in the videos seem to do the same.

It's a tractor beam.

It would be great if this could be adapted to provide automated "spotting" for gymnasts by detecting when they were about to fall, safely stopping them from spinning mid-air, and slowly lowering them to the ground, all with jets of air.

Is there a link to the video mentioned to be in the supporting materials?

Download the supporting materials and play the .mp4 files.

What is going on here? This story and these comments are from a day (or a few?) ago but are showing as hours old. Caching?

HN sometimes revives old submissions and fakes the comment timestamps to pretend that they're recent. I've seen it happen thrice before.

https://news.ycombinator.com/item?id=30937892

https://news.ycombinator.com/item?id=33695320

Here too you can see that for example https://news.ycombinator.com/item?id=40207449 claims to be posted "seven hours ago" at the time of this comment. But with a tooltip that it was posted on at 2024-04-30T05:11:46, and indeed the same comment on the user's comments page says it was posted "2 days ago" which lines up with that tooltip.

tldr: tech the tech and use the force… or in other words, move objects in a controlled manner at distance with jets of air.