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Comment by I_Am_Nous | Hacker News Reader

>At least the steering wheel and pedals still behave the same.

For now, companies are experimenting with drive by wire. Don't think I like that concept.

Electronic power steering already exists. It's used in a lot of cars, and has been for at least 10 years. Your car may have one of these systems in it.

In an electric power steering system there are steering angle and torque sensors that know what direction the wheel is turned an how hard it has turned, and this is connected to an electric motor that powers the gears to move the steering rack.

There are still regulations in place that require a mechanical connection to the steering wheel and rack, but try and turn the wheel with the car off and see if your wheels move... But when the car is running when you turn the wheel you're just a voting remember in the system.

There are no such regulations for throttles. Pretty much every car since the late 80s has electronic throttle control and there are no mechanical linkages from pedal to throttle body.

Most of the modern steering systems are just hydraulic or electronic power steering which boosts your input with a hydraulic or electric assist motor. You're still moving the mechanical linkage at any time you're steering, it's just that when the car is off the assist motor is disabled and because modern cars have massive tire contract patches, huge weights, and a lot more caster compared to yesteryear, it's damn near impossible to turn the wheels when the car is off and not moving. If you simply disabled the assist, started the car, and let it roll, you would find that it is only maybe 1.5 times harder to turn the wheel than a classic car with skinny tires and larger steering wheels and such. You're still fully controlling the direction the wheels are turned in said systems, the assist motor simply adds force.

> it's damn near impossible to turn the wheels when the car is off and not moving.

That was also strongly discouraged on older cars and only possible with big steering wheels and good grip. Just move very slowly and the turning becomes really easy even without assistance (and which is what you were thought when this was still a thing in countries with required driving lessons).

Exactly, just have to move it a bit. I owned an old Fiat when I was a teenager so I was lucky to learn how to drive a car without assists. I prefer the assists most of the time though!

Turning my car at low speed with the engine off feels much harder than 1.5 times the turning of an old times car of similar weight. I could hardly make it turn at all when it happened. I don't think I'd be able to make it through a real turn on a road. And I have a small car of about 1000 kg.

You also have to overcome the little but non zero friction of the power steering and your steering wheel is considerably smaller than they used to be.

Yup, cars designed for power steering don't work as well without it as cars specifically designed to operate without power steering. Not just the steering wheel size, the whole steering geometry is probably different.

> “There are still regulations in place that require a mechanical connection to the steering wheel and rack”

Are you sure? Fully “steer by wire” vehicles with no mechanical steering link are already in production. The Tesla Cybertruck is the most well-known example.

Toyota/Lexus has also been demonstrating steer-by-wire for a while (Lexus RZ), and it will apparently ship in consumer vehicles later this year.

Are any of these cars available outside the US? From what I've been able to tell, US regulations are much weakest in this regard which is possibly why there are so many words cars there.

The Lexus steer-by-wire tech is expected to ship in Europe later this year:

https://www.drive.com.au/news/toyota-lexus-steer-by-wire-sys...

(In some aspects the US automotive regulations are actually stricter than in Europe. For example, in Europe there are some vehicles (eg: Audi) where the wing mirrors are replaced by screens/cameras, but this is not permitted in the US. Adaptive matrix headlights are also not allowed in the US.)

Adaptive headlights are coming soon.

> Pretty much every car since the late 80s has electronic throttle control and there are no mechanical linkages from pedal to throttle body

Electronic throttles became widespread much later than the 80s. Pop the hood of common 2000s economy cars and you’ll find a mechanical throttle linkage.

> Pretty much every car since the late 80s has electronic throttle control and there are no mechanical linkages from pedal to throttle body.

All 90s cars I've had or worked on had a real cable from gas pedal to throttle body.

Even fuel injected ones?

Yes, the throttle cable operates the opening of the throttle. Downstream of that is the airflow meter which is an input to the fuel injection computer so it knows how much air is going in.

Throttle body is a part of fuel injected engines. It was mechanically operated before the electronic throttle bodies.

Being able to feel the resistance of the road is valuable, especially in inclement weather. Much more so than with, say, an airplane.

Experimenting? It’s been around for a long time. My 1999 Jetta had it. It’s smoother and you can control the fuel adder on throttle opening from all angles. Sure, it’s not instant, but stabbing the gas in a non dbw is not great either. In electric cars there is no other way than dbw

A 1999 Jetta doesn't have steer-by-wire. Wikipedia says the first production car to have it was the 2013 Nissan Infiniti Q50.

Well I see what you mean. Steer by wire is part of drive by wire if you want to be specific. But before that was a thing “drive by wire” meant a throttle body controller by the ECU.m for many years. So if you go to a shop and say DBW what the other end hears is “stepper throttle”

It had duplicated mechanics

It's be really cool if there were some giant high power potentiometer connected directly from the batter to the motors in an EV. Just smash the pedal, see a blast of plasma and you take off. Just like slot cars. I can't see a single downside to this :p

Why? Brake by wire is already a thing.

If my steering wheel isn't connected to my front wheels mechanically, that's asking for a lot of trust. Previously a severe mechanical issue would be the only thing to worry about. Maybe on an EV with always connected and charged batteries it would be better, but on ICE I can imagine a number of ways the electrical system suddenly fails and now the wheel does nothing, even if just for a short lag.

At least on brake by wire ICE systems I could let engine braking slow me if the brake system fails somehow (even if I have to blow the engine to save my life, worth the trade).

Having previously driven a car with a mildly unreliable power steering system, it’s an extremely good thing that the power steering was backed up with a mechanical linkage (that worked very well — it was surprisingly subtle when the power steering crapped out at 30mph).

A drive-by-wire system had better be a lot more reliable and also notice impending failures.

I personally cannot stand power steering systems. There’s always a dead zone and the feedback is delayed, in some vehicles more noticeably than in others, but it’s always there.

I feel like I have had several close calls that would have been accidents for sure had I been driving with power steering.

What car do you have without power steering? Or, are you referring to electric as opposed to hydraulic power steering? I haven't seen a car without power steering since the early 00s (which was a 90s car).

The steering deadzone is not purely a function of power steering. Some of it is design or could be attributed to that, but a bunch of it also comes from slop in the physical connections in the steering column, as well as the suspension bushings, your tyre profile, etc.

It turns out I was mistaken! I haven’t done enough research to determine the actual cause of the effect I have noticed. It might be hydraulic vs electric but I don’t want to make that assumption and be wrong again - I’m going to have to research the steering in other cars I’ve noticed that issue in.

There’s definitely a different feel to the electric motor driven assist. Though there are just many different implementations probably the specific one you had was particularly quirky.

Relatedly I had a Hyundai i30 for a while which has a well known fault where the plastic gear connection (called a Spyder Bush) from the electric motor to the steering column would break. Resulting in slop and a clunk. Not hard to imagine similar failures or bad design.

I once drove an early car with an electric steering assist system. (It was either a renta or a test drive, I think it was an American car, and I don’t remember what brand or model.). It was terrible. There was essentially no feedback from the road to the wheel.

These systems have improved.

> it was surprisingly subtle when the power steering crapped out at 30mph

It's not a problem at those speeds, having it crap out when turning slowly and sharply around fast traffic is much more likely to be deadly.

The opposite is true. Those old AMCs without power steering were just as easy to steer on the highway as any other car (once you managed to get up to speed) but the parking lot was a chore and parallel parking was neigh impossible.

Fancier power steering systems basically fully disengage at speed because you don’t need them; they’re for moving the wheels when you’re stopped or nearly so.

I guess I got the wording wrong because that's exactly what I meant.

The most dangerous situation I encountered was turning left across traffic from a stop.

Yeah that's exactly what I was thinking about (and thought I wrote, but the downvotes say otherwise).

If your steering assist conks out just as you're trying to turn at slow speed you could end up heading into oncoming traffic, at an angle at least.

It's actually pretty dangerous, good thing you don't drive it any more.

A combination of whatever fiddling the mechanic did and making sure the fluid was topped off seemed to solve the issue. Also, it was a good, if somewhat old, car, and the mechanical steering was quite good. I was able to steer it without much difficulty at pretty much any speed even in no-power-steering mode.

But yes, I agree, unpredictable steering response is dangerous.

Mechanic connections can, and do, fail. Ask Ayrton Senna. AFAIK, steer by wire are already doing full redundancy, like it was a plane.

There has been a number of plane accidents related to physical connection between the yoke and the actuators (cables loosing tension under high temperatures, or cut/trapped on a deck failure). Electric cables does not suffer that, and they are easily doubled.

SbW makers are already making software that does constant surveilance of the system, something that traditional systems has never done.

The number of dead people caused by the steering column going straight through their chest in a collision is huge. That shouldn't happen with SbW.

I hate the trend towards car controls in a screen, but Drive by Wire sounds like a real advance towards better cars to me. DbW without redundancies and continuous tracking could be a safety issue, but with them I don't think it's an issue. Fly by Wire has a good safety record.

>Fly by Wire has a good safety record.

Because there are dozens of people helping keep each plane safe.

Post ALB there isn’t the same feedback thru breaks as there are steering. Steering systems have been highly engineered so you can get feedback from the road while still having power assist.

There must be a physical connection though? How do you stop if you're out of power? If not, I can only think of truck-like system where brakes are "on by default" and user input disactivates them.

Boeing.

Drive-by-wire is at least a decade old if not more.

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