Nissan intend to introduce steer-by-wire cars by 2013.
www.bbc.co.uk/news/technology-19979380
Will you be happy to buy one?
"... we would be able to place the steering wheel wherever we like," said Masaharu Satou, a Nissan engineer, "Such as in the back seat, or it would be possible to steer the car with a joystick."
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Another technological marvel to add to my list of not-on-your-nelly.
Beggars the question why?
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I can understand it if there's a substantial weight saving and we're happy enough to fly around in aircraft that have been doing it for decades.
Construction and use regulations may need to change, AFAIK there has to be a mechanical linkage for steering and brakes.
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Aircraft are one thing and cars are another.
They would certainly have to overcome my consumer resistances if they expected me to pay good money for a car without a reliable failsafe steering linkage. Everything electronic will be suddenly and definitively killed the moment someone lets off a nuclear weapon nearby, which I can't help expecting to happen any moment. How does Nissan expect us to flee from the carnage? Eh? Eh?
Where are you Number_Cruncher? I know you will want to tell us that cars can do it better than we can and cheap Chinese chips are cleverer and more reliable than we are. Not to mention the actuation machinery. Speak up man!
Edit:
:o}
Last edited by: Armel Coussine on Thu 18 Oct 12 at 00:26
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The cars will initially have a mechanical backup in the event that the fly by wire system fails. However the lack of feel that Nissan says will be an advantage is surely a disadvantage?
I believe fly by wire systems were first used in the Concorde (and maybe earlier on fighter jets?) on a very basic level but the first true passenger plane to use them was the A320 in 1988.
However on a plane you have lots and lots of redundancy built into the the fly wire system, something you could never do in a car.
Personally I can't see the technical being a success, there is a reason this technology has been around for 30 years but never really being used in cars. There is a reason the basic layout of car controls hasn't changed since the Austin 7 in 1920s!. Sometimes things just work so well there is no point on changing them. However if this system really does react quicker than a mechanical system maybe it will take off.
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>> However if this system really does react quicker than a mechanical system maybe it will take off.
>>
I don't see how it can react faster.
You turn a wheel that's firmly attached to a shaft that's firmly attached to a steering box/rack that's attached to the road wheels by ball joints.
These days there is no play....
And as for using a joystick..... God help us.
With a steering wheel you are using a device that is located firmly. the only input it accepts is the rotation in the direction you wish to turn.
Imagine a sneeze.
With a steering wheel, a sneeze makes little variance to the direction of travel (normally)
Now imaging the same sneeze using a joystick.
Also, when cornering, g-forces apply on to your body.
Because you are holding onto a fixed item (the steering wheel) that g-force makes little input to the steering system.
Again, imagine the g-force affecting your body, but now using a joystick........
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>> ......... the fly by
>> wire system .............
>> ............ maybe it will take
>> off.
Good joke!
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I had cable brakes Superceded 50 years ago.
And now we are going to have cable steering..
And they call that progress?
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Citroen had a steer-by-hydraulic system in the 70's on the CX (carried over onto some XMs) called DIRAVI. In normal running there was no direct mechanical link, but there was an emergency link but it had a lot of play in it. I've not driven one, but by all accounts it's a slightly odd experience - it has a very strong self centering response, so is not deflected by bumps in the road etc - and if you let go of the wheel on lock while stationary (engine running) the steering centres itself!
I remember seeing a SAAB (?) demoed on some TV programme quite a few years ago with a joystick steering system.
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We all know the joystick in cars is coming, it has been for years and years. Every boys SciFi comic since the mid 50's has had a joystick controlled car, every car designers futurist mock up has got rid of the steering wheel, A whole generation of kids has and is growing into adults having driven racing cars round tracks with joysticks on the PC.
You may not like it but its coming. Its going to be a problem for us Brits, the natural place for the joystick is in the Centre console, we are all going to have to get pretty skilled up with using the left hand. Start practising now.
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Perhaps we're missing the point here. Conventional steering, whether assisted, unassisted, hydraulic or electric, is proportionate and the steering is controlled by the human at the tiller.
With FBW, you might still have a steering wheel. Then you have a computer between that and the steering actuators. It's actually the computer that decides where the wheels point. FBW accelerators are similar, the pedal doesn't control a flap or the fuel injected, the computer does that - so e. g. it can cut the throttle when you press the brake, regardless of where your right foot is.
Airbuses do different things when you waggle the stick (they don't have a wheel either) according to what mode they are in and what protections are operating.
In a skid for example, the computer could 'take over'. It would be easy to vary the steering rate according to speed or steering angle or direction if travel. The wheels could be steered independently with great precision, so steering geometry could be improved ( there's quite a lot of error in a mechanical linkage of the two road wheels).
The computer hardware and software would need to be super reliable. As would the power supply. Redundancy all round. And it would be very expensive to develop. Possibly not too expensive in direct cost to manufacture. But reliability would have to be almost 100% with sophisticated monitoring and error handling so when it did go wrong it didn't do it catastrophically. That said, mechanical steering failures are not unknown- just rare.
It's a solution looking for a problem maybe - but maybe not for long.
Dual controls would be easy. And packaging will be easier without steering columns to accommodate. Quite a few other developments become possible when you move to digital.
Edit - crossed with Zero. Yes I agree we will probably end up with sticks or 'handlebars' of some kind. Just no need for a wheel.
Last edited by: Manatee on Thu 18 Oct 12 at 08:16
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>
>> FBW accelerators are similar, the pedal doesn't control a flap or the fuel injected, the
>> computer does that - so e. g. it can cut the throttle when you press
>> the brake, regardless of where your right foot is.
Developing the system for cars is a much easier prospect than aircraft. We are only talking one control plane - lateral left and right here, and we have much more positive and accurate feedback already being supplied to the computer from the wheels used for the various stability programmes. As far as these technological challenges goes, its the nearest thing to a doddle you get.
As far as back up goes, I doubt many woman could cope with a failure of todays power assisted steering, the physical input required is enormous when speeds drop.
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Steer by wire has interesting possibilities as it could be linked to stability control so you could never ask the car to do something it wasn't capable of.
>>>Citroen had a steer-by-hydraulic system in the 70's on the CX
Owned 3 CXs. I loved the system. Only 2.5 turns lock to lock, self return to centre while parking and totally unaffected by road shocks (i.e zero kickback). Feel was artificially generated and when driving on the limit you developed a whole car seat of the pants feedback to judge steering input.
The mechanical failsafe was a bit weird with it needing an input that felt like 1/4 of a turn before much happened but was probably a bit less.
Last edited by: Fenlander on Thu 18 Oct 12 at 08:44
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>> I believe fly by wire systems were first used in the Concorde (and maybe earlier
>> on fighter jets?) on a very basic level but the first true passenger plane to
>> use them was the A320 in 1988.
>>
It was working in the late 1970; databus, quadraplex and all that jazz on aircraft.
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Its all about reducing weight and cost.
Electronics and electric actuators weigh less than mechanical linkages. Shave off a few kg on every susbsystem, then you can build a lighter chassis, with a smaller (lighter) engine to propel it. The 'virtuous circle' Number Cruncher referred to with regard to the 1 litre Focus.
All this costs less to build because you can slot a completed subassembly into the car rather than having to assemble it in place. And you can use the same steering controls for every model, so there's economy of scale. Tooling for left and right hand drive becomes a matter of moving the wheel (they'll surely retain the steering wheel, because its what buyers are used to) from one side of the cabin to the other. Remember how Rover SD1s had a modular dashboard on which the instruments and steering column could be swapped for RHD and LHD markets?
Will most buyers care? No! How many know, or care, whether the car they buy today has rack and pinion steering, hydraulic assist power steering, or electrically assisted? Lets be honest, the world's biggest selling car is the Toyota Corolla, and its not as if they ever had anything that could be described as "steering feel"...
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...[redundancy is] something you could never do in a car.
I don't see why not: we've had dual-circuit brakes for decades, which must be far more complex, heavy and expensive than a few redundant steering actuators. My car also has redundant tail-lamp bulbs, so the concept is clearly familiar to car designers.
As for Zero's idea that the natural place for a joystick is the centre console, fear not: if that were the natural place for the steering it would already be there. Doing away with a mechanical steering column would mean that any car could have a sliding or swivelling control position that could be set for either side of the car - no more market-specific LHD or RHD versions, although you'd still need a symmetrical or adaptable way to let the driver see in the rain. I can see the car makers going for this in a big way.
It's the way technological progress works. A better example from aviation might be the development of long-range twin-engine aircraft. 25 years ago twins were barely allowed out of sight of land, but the aircraft and engine makers have now demonstrated reliability to the point where 777s are certified to 330 minutes from a diversion airport and the A350XWB will be certified to 350 minutes, meaning they can fly practically anywhere on earth. No doubt there were those early doubters who refused to fly the Atlantic in a 767, but it's a matter of course now.
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See section 4.1.6 of
eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:1992:199:0033:0047:EN:PDF
seems to suggest that you cannot have a purely electrical steering system. However, I'm not a lawyer.
However, the original directive, 70/311/EEC is due for replacement in 2014, so, perhaps the law will change then.
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Some Liebherr cranes have hydraulic-only steering.
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I've had International tractors with no mechanical backup. Very weird as it was possible to keep turning the steering wheel in the same direction round and round.
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Like the volume knob of a modern car audio - looks conventional until you twiddle it and realize there's no potentiometer behind it. Haven't had one fail yet, whereas pots get crackly and eventually give up altogether.
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With all due respect N_C there wasn't any information at all there, just a lot of vague claims. Please tell us whether you are keen to have a car with this (still putative?) arrangement or would prefer in practice to have something, er, more reliable.
I don't want it, or electric steering come to that. Expensive troublesome Heath Robinson hydraulic assisted steering seems far better. If it costs more, so be it. I don't want to go up a tree still boasting that my car was cheap.
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>> Hobbyists are already doing it entirely wirelessly. See
>>
>> arduino.cc/blog/2012/05/13/the-age-of-the-invisible-steering-wheel/
>>
Yup, and at 56sec it appears to lose control - at 60sec it runs over the curb....
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Could be interesting, as I thought Ackerman sorted the problems of steering angle of each wheel. IIRC NC disputes this.
I've got the popcorn and notebook.
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At the risk of becoming known for paranoia, could such a system also enable external guidance/control of steering? Might help a future Govt. implement a long held desire to control cars via convoy systems.
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I agree, little by little cars are becoming remotely controlled, along with that silly 911 black box that will phone the regime if you crash or the regime can phone the car and disable it, or all cars in a certain area where they are carrying out 'an operation'.
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>> Its all about reducing weight and cost.
It's all about more profit. I'm sure the reduced cost will be not be passed to consumers. Rather that would market drive-by-wire as a feature and thus will up the price. Net result, more profit for them!
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Naturally, Movilogo: building cars is a business, after all, so (unless you're Renault) you need to make a profit from it to stay in business!
As a typical family car, compare the purchase price of today's Cashcow with the Datsun Cherry relative to income and other daily expenses. Cars have never been so cheap, nor so reliable.
And yes, various forms of "remote control", be they conveyor-belt motorways, park assist or collision avoidance, all become easier to implement as the various functions of the car come under electronic control. This is a by-product of the drive to save weight/reduce parts/reduce manufacturing cost, but these are added features most buyers will pay extra for. Again, that's business.
Those of us who don't like the idea can always buy a Dacia Duster :-)
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Steer-by-wire Nissans. - -
