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Comment by shostack | Hacker News Reader

Are there any engineering advantages from choosing this design vs. a more traditional arm, or plug that just moves on two rails up or down and then extends out?

In theory, there is minimal height distance from where such a charging station would be in relation to the car and the charging port height, even when accounting for different Tesla models. As such, I'm not clear why they went with something that on the surface appears overly complicated unless it was for the "wow" factor.

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The snake arm is quite simple. The "snake" part is a set of dumb hinged segments; it's all cable-driven from the base. The application does not require much rigidity or repeatability. The load is low; it's just carrying a power cable. There's probably a camera at the end of the tentacle to guide the connector to the car's power socket. The car opens the connector cover, so there's no need for a mechanism on the robot to do that. This is much simpler and far less bulky than the automatic fueling systems that have been built to refuel cars.

The marketing value of this is enormous. People won't have to get out of their cars and get their hands dirty handling a gas hose. This is going to go over big with women.

This is going to go over big with everyone - Men are just as happy to be lazy and stay warm as women are.

And it's Tesla, so they already won't handle a gas hose, just a glorified electric plug.

> The marketing value of this is enormous. People won't have to get out of their cars and get their hands dirty handling a gas hose. This is going to go over big with women.

I think you're underestimating the benefit here. From my talks with Tesla owners, some of the Supercharger stations are pretty far out in the middle of nowhere (for coverage, they have to be).

Late night charging in a rural area without a lot of people around driving an expensive car?

On the plus side, I'm sure the creepy prospect of Terminator-esque robotic snakes dancing idly (maybe Stravinsky's "Infernal Dance" over speakers?) would in and of itself help to deter any would-be muggers from loitering.

How long does the recharge take? Are people really going to sit in their cars for 30 minutes?

You're right , the tech isn't hard. For example there's this arduino hobby project , a swimming robot snake:

http://www.instructables.com/id/Make-a-swimming-Robo-Snake/

The huge benefit will be when this is used in conjunction with the self parking system. You drive up to the front of your house, get out, and the car drives itself into the garage and plugs itself in.

I completely agree. I came here to say this but see you beat me to it! I might add that this could be used to park your car miles from where you live. You would simply let your car know when to pick you up and it would come to you like calling the valet at a hotel before heading out. If tesla had overnight parking garages/chargers scattered around we could use all that garage space in our houses for more activities!

I'd always seen electric vehicles and fully autonomous vehicles as synergistic technologies for this reason. Certainly, in the part of town where I live, no one has garages or even driveways, so electric cars as they stand would not be practical here.

That's a really interesting thought once you consider where autonomous vehicles are going with Uber and Google's self-driving vehicles.

It makes a ton of sense that any such vehicle, in addition to going to pick you up, drive you around and drop you off needs to be able to park itself at home base and refuel in an automated fashion.

Yeh way cool, you don't need a driveway or garage then. It would be good to reclaim that space.

I assume the purpose is for a driver to just pull into the garage and have the charger hook up automatically, so a two-rail system would probably not be able to deal with the car being parked at a slight angle and not completely perpendicular to the plug.

The dead-simple solution for aligning the car is to make it drive onto alignment rails. Or, given that it can auto-park, just give it an auto-pump-align routine based on that.

The true benefit of a "smart pump-side alignment" system, I think, is that it copes with different models of vehicles (e.g. EV SUVs, EV 18-wheelers, etc.), with their charging ports in different places and orientations.

Why make the driver adapt (driving onto rails, etc), when the charger can adapt?

Beyond being able to handle almost arbitrary orientations and alignment between the car and charger, Elon is probably planning on reusing this tech at SpaceX for docking or other purposes (just like they share battery tech).

He's a pro at coming up with "synergies" between his companies.

Hadn't considered that at all, and you are right that there seems to be some real winning synergies between his companies. Interesting implications.

Indeed, this may have even come out of Space X.

While something bound for space needs tons of testing, loads of refinement, and to be the absolute minimum weight possible, the worst that could happen with this in your garage is... what? It can't find the socket so it beeps angrily at you until you move the car closer.

So, it might be partway through it's development cycle for Space X, but good enough right now for use here on earth.

TBF, for space technology it seems far too complicated; you'll want less components, not more. Less components means there's less chance of failure and less weight. I mean I'm pretty sure each segment is motorized or has cables running to it with separate motors.

I'm guessing it's because the charging cable is fairly thick, making bending it arbitrarily fairly difficult. This design will make sure that the cable isn't too strained while integrating it as one piece.

You can definitely solve the problem using a traditional arm though -- so maybe it's just for the cool factor for now.

Yes, this design is far more compliant to external movement and also the stage can be far smaller than something needing three axis of freedom.

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