h a l f b a k e r yNeural Knotwork
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Steering columns are notorious for impaling drivers, or exploding their heart in collisions. Also, they are an impediment to modularity in vehicle design.
So the idea is that the steering wheel would be attached to a hydraulic pump, and two flexible hydraulic hoses would lead to a double-acting hydraulic
cylinder that would replace the rack-and-pinion assembly.
Power-assist optional (and easily implemented). Left/right drive easily swapped. Driverless (computer piloted) configuration easily swapped in or out.
Failures (i.e. leaks) easily detected, and very unlikely to cause sudden complete loss of steering.
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A rack and pinion is a physical mechanical linkage.
While catastrophic failures are possible, they're
extremely low probability. |
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This approach is dependent on a hydraulic pump,
which will fail in the first place. Also, while leaks
might not be a huge issue, a burst hydraulic line is
another story, and not exactly unlikely. Finally,
spraying hydraulic fluid is not exactly much more of a
friend in a wreck than a steering column. |
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//dependent on a hydraulic pump, which will fail in the first place// |
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Mmmmm. Most boat steering is hydraulic, and there are extremely low maintenance/failure versions of that. Twin redundant systems could easily be implemented. |
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I'm not saying this is a great idea, but I think the reliability could be addressed. Run a 2000PSI system with 5000PSI hoses is a good start. |
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Not bothering to look this up, but have a sneaking suspicion Citroen may have monkeyed around with this.. |
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It's probably cheaper and easier and safer to use
electrical rather than hydraulic control. |
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If you argue that (hardwired) electronics are more
fault-prone than hydraulics, I'd question that. But,
more to the point, you can have fourfold redundancy
in an electric circuit for less than the cost of twofold
redundancy in hydraulics. |
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Electric power steering is totally baked, has complete
industry confidence, and has notable advantages with
regard to selectable effort ratios. Whereas the notoriously
hyraulicophillic aircraft industry is already going electric. |
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"Hahaha, they're all gonna die
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Hydraulics good, electrics
very bad. |
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// car companies and putting animals under the bonnet ? // |
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Well, they've been putting them behind the steering wheel since
automobiles were invented
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I first read thus as a system where the steering
wheel controlled hydraulic pumps making a drive-
by-hose system. On more careful reading, I think
the idea is to have the steering wheel turn the
hydraulic pump. Assuming a reversible positive
displacement pump, that would automatically
provide feedback to the driver, just like a
mechanical connection. Also, it could operate
when the engine is off, just like power assist
brakes. |
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Considering that we trust hydraulic brake, steering
doesn't seem like too much of a stretch, but I
wonder might result in too much play in the
steering. In brakes, if you have a tiny air bubble,
it makes the brakes a little soft and less
responsive, but generally that isn't serious.
However a small air bubble in hydraulic steering
would make the steering springy. Also, brakes
lend themselves to an efficient redundant system
because a car can have two wheels on each
hydraulic system, making the only overhead be the
slightly more complex master cylinder. When one
fails, braking performance is reduced but still
works. For steering, making the system redundant
seems harder to do efficiently. I can't think of any
way that steering performance can be reduced
that is acceptable, so both redundant systems
must be fully capable by themselves. |
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I generally like electronics, but in this case it
seems a little iffy. I'm all for electric assist, but if a
failure of the electrical system will cause me to
loose steering control entirely, I'd be worried.
Therefore we'd need a whole backup electrical
system complete with a second battery. |
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Close all the windows and restart? |
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Electric power steering is burnt to a crisp. Power
steering pumps are burnt even crispier, and
collapsable steering columns are deep-fried.
What's new here besides having a horrible system
with no road feel? |
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But....you could have the steering wheel in the back seat.
How cool would that be? |
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PS. pure hydraulic steering is found on articulated front
loaders, and fork-lifts. |
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^ and articulating dump trucks. <side note> they are made to rotate longitudinally as well as articulate side to side in case the load tips. I found out the hard way. Ended up half-in half-out of the passenger window... ...good times. |
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//you could have the steering wheel in the back seat. |
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like th Viz cartoon asking why the driver gets to sit at the front, while the paying passengers have to sit behind him/her |
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A double-decker bus coud be driven from the upper deck. That woud
help reduce bridge strikes from "stray" buses ... |
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It would also allow improvements in disabled access. |
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Electromechanical steering is considered the newest and
best technology. Solid state with no moving parts, no pumps
or pipes that can leak, etc. |
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//no moving parts// so hw does that work? An electromagnetic field constraining a shoe that slides along the road surface? |
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