Steer-by-wire

[kambites]

http://www.bbc.co.uk/news/technology-19979380

I didn't actually think this was legal in the EU?

I like the way they're billing the fact that it removes steering feel as one of the advantages.

[kambites]

Captain Muppet said:

Is that a steering column in their diagram?

It's a clutched steering column as an active fail-safe. Which presumably also needs to be activated by the computer that they're worried about failing.

[kambites]

nosittap said:

As a driving enthusiast, I think it's a shocking idea, but it'll probably never make it into a 'drivers' car anytime soon if ever.

People were saying the same about electrically assisted power steering a few years ago... I think this is just the next step down that path.

[kambites]

renrut said:

I wonder what would happen if the mech clutch cuts in suddenly - likely to pull the wheel from your grip?

I'd be more worried about what will happen if the car's power fails and the clutch doesn't cut in.

[kambites]

sjg said:

Didn't everyone say the same about power steering when it was introduced? Have you tried steering a car when the PAS has failed recently?

At least if power steering fails it tends to continue going in a straight line and you have dome control. A bug in the firmware in this could make the car go anywhere.

[kambites]

renrut said:

And to keep a mechanical backup you'll still need the wheels connected to eachother. Independant wheels doesn't really work - why would you need that other than weird parking maneuvers?

Dynamic toe adjustment?

[kambites]

PSBuckshot said:

Oh, I was thinking of Mr Bean.

That was more "steer-by-string".

[kambites]

You could design a conventional steering system with adjustable geometry - you'd just need hydraulic rams in the toe-links or rack-ends.

[kambites]

sjg said:

They've been doing this in aircraft for decades, without mechanical backup. Why not cars?

Well for once thing air craft generally have rather more regular, more stringent safety checks than cars.

I do agree though - it's probably the natural next step on the slow path to cars with no human control mechanism at all.

[kambites]

Big Fat Fatty said:

How does the system work in aircraft, is it just the landing gear or is it connected to the control surfaces while in the air as well?

I think some modern passenger planes have no physical link between the cockpit controls and any of the fight surfaces.

[kambites]

mat205125 said:

Big Fat Fatty said:

How does the system work in aircraft, is it just the landing gear or is it connected to the control surfaces while in the air as well?

Eurofighter doesn't have any mechanical connections between the pilot's controls and any of the control surfaces, and their inputs are measured and processed by computers which then actuate the control systems of the plane.

I seem to remember reading that the Eurofighter is fundamentally unstable, and that it wouldn't be realistically possible for a human to fly it without computers even if there was a physical link.

[kambites]

BriC175 said:

Even if this was the only problem (which I'm not convinced it is), then why would you actually apply the electronic steering? What benefits would it provide?

I suspect the big one in the long run is packaging - no need to find a path through the engine bay for the steering column.

[kambites]

Triumph Man said:

So, and apologies if it has already been said, if there is still a steering column, what the hell is the point of an SBW system? Just another useless piece of technology for technology's sake. Bah humbug.

There is in this case because they think it's needed to make drivers feel safe. They have stated that the column is unnecessary and they will be aiming to remove it in future cars, though.

[kambites]

Triumph Man said:

The thought of it all still makes me grumpy, though...

Even the thought of power steering makes me grumpy, but sadly it seems to be the future.

[kambites]

mat205125 said:

Without prior knowledge, and therefore preconcieved prejudice, of whether a car is so equipped, it's nearly impossible to detect whether the car you are driving has a throttle cable or electronic actuator.

You can easily tell that a badly implemented electronic throttle isn't a cable; you can't tell a good one though.

However, the throttle pedal is not really a control that provides feedback to the driver - as long as the response is linear and the spring rating is right then it's fine; the steering is.