The next step in removing feedback from cars: steer-by-wire

[cyde01]

http://www.autoblog.com/2012/10/17/n...y-wire-system/

with dbw already being introduced in sports models, i wonder how long before they start putting steer-by-wire in sports cars? i hope not anytime soon.

[RaceR]

Nooo!
just.. noo...

[serialk11r]

I thought the Lexus LS460 already has this? Apparently what happens on the earlier ones is that if you try to turn the wheel really fast lock to lock the steering wheel loses its position and awkwardly returns slowly to the correct position. At least that's what I saw in a video.

I think they also use brake by wire with hydraulic backup.

I don't understand the point, you already have a steering rack, why not just...you know, attach the steering wheel to it? And you already have a brake system, why not you know, attach the brake pedal? Electronically controlled throttle is another matter, because the throttle can interact with the valve timing and it's better than a reactive system theoretically.

[midenginebias]

I don't like it, but they do this to cut weight and improve gas mileage by tenths.

[serialk11r]

Originally Posted by midenginebias

I don't like it, but they do this to cut weight and improve gas mileage by tenths.

Well, if they come up with a design that actually cuts weight. I'm still a believer in steering racks that take effort. Afterall, it's called "assist" right?

I don't understand why so many companies think that it's not okay to ask the driver to put some effort into turning the wheel.

[midenginebias]

Originally Posted by serialk11r

Well, if they come up with a design that actually cuts weight. I'm still a believer in steering racks that take effort. Afterall, it's called "assist" right?

I don't understand why so many companies think that it's not okay to ask the driver to put some effort into turning the wheel.

I'm all for manual steering with a quick rack and mid to rear engine setups, believe me.

The thing is, there are far less automotive enthusiasts than people who just want practical cars. It doesn't make sense to me that Porsche or BMW implemented electric power steering, nor does it make sense to me that the Rx-8's electric power steering is the best I've ever tried out, yet it's been so difficult to replicate.

I wonder how much easier it is to build cars in LHD or RHD with electric power steering instead of a traditional linkage.

[serialk11r]

Originally Posted by midenginebias

I wonder how much easier it is to build cars in LHD or RHD with electric power steering instead of a traditional linkage.

I think something a lot of people don't realize is that almost all of these "electric" power steering systems are electrohydraulic just like our Spyder, or the BRZ (one of the aftermarket developers was talking about the pump being cleverly placed or something). They have the same (rather flexible) torsion spring, fluid passages, and rack, just an electric powered pump. I haven't thought about it enough to see a possible reason for why everyone thinks the steering feel has gotten worse on cars.

What's for sure is that belted power steering pumps do suck up a lot of power at higher engine speed.

[madfast]

Originally Posted by serialk11r

I think something a lot of people don't realize is that almost all of these "electric" power steering systems are electrohydraulic just like our Spyder, or the BRZ (one of the aftermarket developers was talking about the pump being cleverly placed or something). They have the same (rather flexible) torsion spring, fluid passages, and rack, just an electric powered pump. I haven't thought about it enough to see a possible reason for why everyone thinks the steering feel has gotten worse on cars.

What's for sure is that belted power steering pumps do suck up a lot of power at higher engine speed.

the FR-S/BRZ doesnt have electrohydraulic PS





http://blogs.insideline.com/roadtest...alkaround.html

it has column mounted EPS, most likely made by JTEKT. what other car has that same setup? the LFA... so EPS in and of itself isnt bad. the only thing "bad" are the people who expect no steering feedback, and call it luxurious, and the manufacturers who oblige and make cars with little to no feedback... and on that front, steer-by-wire sounds very good at filtering out feedback that we enthusiasts actually want. but for the yuppie businessmen of the world? steer-by-wire is great for them...

[serialk11r]

Originally Posted by madfast

the FR-S/BRZ doesnt have electrohydraulic PS

it has column mounted EPS, most likely made by JTEKT. what other car has that same setup? the LFA... so EPS in and of itself isnt bad. the only thing "bad" are the people who expect no steering feedback, and call it luxurious, and the manufacturers who oblige and make cars with little to no feedback... and on that front, steer-by-wire sounds very good at filtering out feedback that we enthusiasts actually want. but for the yuppie businessmen of the world? steer-by-wire is great for them...

Oh interesting, thanks for the correction. One of the aftermarket developers or something said the integrated PS pump was really small or something along those lines.

But still, there's a difference between steer by wire and electric assisted power steering. ---- by wire means the only thing the controls do is input a digital signal to the system that controls what you want it to control. Steer by wire essentially means zero feedback, because the wheels are supposed to turn exactly where you tell them to turn, and you're supposed to be able to decree that position independent of what forces the wheels are undergoing.

[madfast]

Originally Posted by serialk11r

Oh interesting, thanks for the correction. One of the aftermarket developers or something said the integrated PS pump was really small or something along those lines.

perhaps they saw the column mounted electric motor?

Originally Posted by serialk11r

But still, there's a difference between steer by wire and electric assisted power steering. ---- by wire means the only thing the controls do is input a digital signal to the system that controls what you want it to control. Steer by wire essentially means zero feedback, because the wheels are supposed to turn exactly where you tell them to turn, and you're supposed to be able to decree that position independent of what forces the wheels are undergoing.

but it can potentially work both ways. for instance it can perhaps augment feedback instead of filter it out. it just depends on how they program it and the available tech at the time...