Discussion
Instead of having, say, a throttle pedal linked to a carburettor by a cable, you replace the cable with a servomotor and have the pedal tell a computer what you want to do. The computer then fiddles with the servo in an attempt to give you what you want.
Possibly the ultimate expression of this is to be seen in the Eurofighter, whereby the pilot doesn't actually control anything directly. He tells the plane what he fancies doing, let's say full throttle and an outside loop, and the plane performs the hardest manoeuvre it can without breaking anything or having the pilot pass out. In a car this would equate to traction control: you fancy 0-60 in 3 seconds so you floor it: the car feeds in the power as hard as it can without spinning the wheels. Of course it takes the 'skill' out, so 'real men's' cars like TVRs will feature no such thing. Bit like ABS: any clown can avoid an accident with one of those fitted...
Ian
Possibly the ultimate expression of this is to be seen in the Eurofighter, whereby the pilot doesn't actually control anything directly. He tells the plane what he fancies doing, let's say full throttle and an outside loop, and the plane performs the hardest manoeuvre it can without breaking anything or having the pilot pass out. In a car this would equate to traction control: you fancy 0-60 in 3 seconds so you floor it: the car feeds in the power as hard as it can without spinning the wheels. Of course it takes the 'skill' out, so 'real men's' cars like TVRs will feature no such thing. Bit like ABS: any clown can avoid an accident with one of those fitted...
Ian
robp said: Lets hope the system does not run on Windows - cars will be crashing all over the place
>> Edited by robp on Tuesday 8th April 23:06
reminds me of a conversation between bill gates and the chairman of GM - which i can't quite remember fully, but involved BG dissin' the rate of progress of cars relative to compuuters and GM-guy coming back with something about his cars not crashing every twenty minutes.
Was funnier in the pub...
mikeylad said:
robp said: Lets hope the system does not run on Windows - cars will be crashing all over the place
>> Edited by robp on Tuesday 8th April 23:06
reminds me of a conversation between bill gates and the chairman of GM - which i can't quite remember fully, but involved BG dissin' the rate of progress of cars relative to compuuters and GM-guy coming back with something about his cars not crashing every twenty minutes.
Was funnier in the pub...
Another thought;
I drive a 1994 Fiesta. If I wanted to, I could also drive a 1993 Fiesta, a 1992 fiesta etc etc.....
They are the same, they have 4 wheels and an engine.
Windows, backward compatible? No!
I've read about this drive-by wire mechanism such as on the mercedes sl and i was just wondering if anyone could explain it to me in quite simple terms and what is so revolutionary about it.
Appreciate the replies, Gary.
That SL uses steer-by-wire, a joystick operates a servo motor that drives the steering rack.
The advantage would be easier manipulation by electronics which think faster than the nut that operates the vehicle.
Further development will extend the scope to weight saving when using brake-by-wire, steer-by-wire and crankshaft-starter-generators in 42Volt board electrics (as soon as servo motors and accumulators get a better weight/power ratio.
Technical explanation here:
www.tfa.maschinenbau.tu-darmstadt.de/projekte/bo/bo_eng.html
>> Edited by Bodo on Tuesday 8th April 23:51
Hmmm... Yamaha used a starter-generator on the RD200. Either it worked fine or (most usually) you gave up and used the kickstart. Good idea, cack implementation.
If it works by being wrapped around the crankshaft, either it'll have to be new casings (and thus more bulk) or very compact, which will probably equate to nil serviceability by the owner. At least now you can (even on a TVR ) simply whip off the wires, remove three (or even 2!) bolts and reassemble in reverse order... 
Ian
If it works by being wrapped around the crankshaft, either it'll have to be new casings (and thus more bulk) or very compact, which will probably equate to nil serviceability by the owner. At least now you can (even on a TVR
) simply whip off the wires, remove three (or even 2!) bolts and reassemble in reverse order... Ian
This COULD get very interesting as someone has already suggested. Remember the Airbus being displayed at the Paris airshow a few years back?
The Airbus range is all fly-by-wire ........ the pilot told the plane to land and then he was going to throttle up again and do another fly past for the crowds. The computer understood his commands and put the flaps down, wheels down, reduce speed etc etc. As the plane was about to touch down the pilot started to throttle up and 'told' the plane to increase altitude again ........ computer wasn't interested ...... as far as it was concerned it had been told to land BUT it understood that maybe it hadn't quite reached the runway so had to go a bit further. The result was that the plane held it's altitude at roughly 20-30 feet and carried on straight into a forest at the end of the runway. This was a computer programming error.
Sorry officer, I know I went straight through the red lights but the computer wouldn't let me brake for some reason ... some great new excuses if this technology takes on !
Did you see the documentary about that?! talk about a corporate cover up, the black boxes were substituted with doctored info (independant experts dismissed them as nonsense) the surviving crew member tried to take it further and was subsequently stripped of his flight crew status and deemed mentally unfit.
Very unsettling stuff but to be fair it did make a perfect landing albeit in the middle of a forrest
Very unsettling stuff but to be fair it did make a perfect landing albeit in the middle of a forrest
I've read about this drive-by wire mechanism such as on the mercedes sl and i was just wondering if anyone could explain it to me in quite simple terms and what is so revolutionary about it.
Appreciate the replies, Gary.
if you are familiar with radio control cars you can substitute most of it with the joystick on the controller sending commands to a motor (servo) in the model car (via electrical wires rather than via transmitter/receiver).
In reality it is a tad more complicated and involves a closed loop PID control which I'm too bladdered to describe right now
One additional major advantage of drive by wire is the package space it frees up. Steering columns and their crash performance have significant effects on car design. Also electronic throttles (which have been around for a little while now) make calibration for emissions more controlable.
Yes but the downside is that if like on my Merc the by wire computer goes wrong and starts trying to over componsate the throttle etc (resulting for the car hunting for revs all the time) it is incredibly expensive to repair, and on an older car the options are spend thousands fixing it, or frig it and sell it................ and this was on a car that was not drive by wire, but did have computer controlled throttle etc.
wedg1e said: Instead of having, say, a throttle pedal linked to a carburettor by a cable, you replace the cable with a servomotor and have the pedal tell a computer what you want to do. The computer then fiddles with the servo in an attempt to give you what you want.
Possibly the ultimate expression of this is to be seen in the Eurofighter, whereby the pilot doesn't actually control anything directly. He tells the plane what he fancies doing, let's say full throttle and an outside loop, and the plane performs the hardest manoeuvre it can without breaking anything or having the pilot pass out. In a car this would equate to traction control: you fancy 0-60 in 3 seconds so you floor it: the car feeds in the power as hard as it can without spinning the wheels. Of course it takes the 'skill' out, so 'real men's' cars like TVRs will feature no such thing. Bit like ABS: any clown can avoid an accident with one of those fitted...
Ian
It all depends on the amount of computer involvement.
For example, pretty much all current Alfas have a fly by wire throttle linkage, but there is no software performing traction control. You floor the pedal and the computer floors the engine, complete with smoking tyres etc until you bounce off the limiter!
The Eurofighter relies on fly by wire to such an extent that the aircraft is actually impossible to fly without the computers. The desigin is deliberately inherently unstable in order to make it exremely agile.
I used to watch the Airbus undergoing FBW tests at Filton - they used to put them into extremely tight spirals in a maximum angle climb. Very scary to watch, but the computer would keep the thing from stalling. Software bugs aside (e.g. Paris), its a good system in that it ought to prevent numpty moments from the pilot...
alfa dave said: One additional major advantage of drive by wire is the package space it frees up. Steering columns and their crash performance have significant effects on car design. Also electronic throttles (which have been around for a little while now) make calibration for emissions more controlable.
and l/h to r/h conversions are a doddle
No one has mentioned that electic steering completely kills all steering wheel feel. Hell most power assistance does that as well, but this would be an order of magnitude worse. Personally I like some feedback from the tyres when they are losing grip.
This isn't a technology I look forward to.
what about a wireless joystick then? choose whatever seat you want to seat on, get out of the car to fiddle it in tight parking gaps, ...
DanH said:
No one has mentioned that electic steering completely kills all steering wheel feel. Hell most power assistance does that as well, but this would be an order of magnitude worse. Personally I like some feedback from the tyres when they are losing grip.
This isn't a technology I look forward to.
I've driven a steer-by-wire vehicle at uni; in fact one of the scientific assistants makes research on a feedback utility for the steering wheel - feels like a normal one.
(see the link I've posted above)
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