RE: Fly by Wire
Thursday 20th June 2002
Fly by Wire
Software throttles
Discussion
There are loads of gadgets coming our way in the near future. One idea is to have a gps device in the car to issue automatic speeding fines! Also, how about the one where the car goes into autopilot and you get 'trains' of cars travelling inces from each other, all controlled by radar. Sounds bonkers but jag already made one that works! There's loads of electrics that'll be getting in the way of our fun.
In 40 years time I'll still be having fun in my 'old' 2002 911, like those old men you see - still driving their old MG's! Better that, than electronic imprisonment.
In 40 years time I'll still be having fun in my 'old' 2002 911, like those old men you see - still driving their old MG's! Better that, than electronic imprisonment.
quote:
Then all will take is one bug in Windows 2015 and the whole car shudders to a halt.![]()
If you're lucky. Would you like your car to be as reliable as Windows?
(There was another thread about this, along the lines of GM's chairman saying how shite cars would be if they were as "advanced" as windows, after Billy Gates criticised cars. He (the GM guy) was right too.
Fly by wire is certainly nothing new. My 1999 LandRover Defender TD5 has a fly by wire throttle.
Its actually quite good once you know what its doing:
Eg. If you drop the clutch suddenly (when stationary) without using the throttle it assumes it's an accident and stalls automatically. This is to prevent rear-ending someone whilst stationary.
On the other hand if you gently raise the clutch with no throttle the computer works out that you want to trickle forward and will automatically raise the revs slightly - making it almost impossible to stall. This is incredibly useful when off-road and you're on a 2 in 1 gradient and stationary becuase you can leave your right foot on the brake and let the clutch up without rolling back.
In normal driving the drive by wire appears to make no difference.
It is odd to look at the pedal and just realise there's 2 wires and 1 big spring
Its actually quite good once you know what its doing:
Eg. If you drop the clutch suddenly (when stationary) without using the throttle it assumes it's an accident and stalls automatically. This is to prevent rear-ending someone whilst stationary.
On the other hand if you gently raise the clutch with no throttle the computer works out that you want to trickle forward and will automatically raise the revs slightly - making it almost impossible to stall. This is incredibly useful when off-road and you're on a 2 in 1 gradient and stationary becuase you can leave your right foot on the brake and let the clutch up without rolling back.
In normal driving the drive by wire appears to make no difference.
It is odd to look at the pedal and just realise there's 2 wires and 1 big spring

quote:Are these figures Imperial or US?
Fuel economy for the most popular ’04 model – the 4x4 with V-6 engine – is expected to increase to 20 mpg from 19 mpg on the ’03 Explorer. Fuel economy for the base model (4x2 V-6) will increase to 21 mpg from 20 mpg. Similarly, metro-highway fuel economy for Explorers with the optional V-8 engine will increase to 19 mpg on 4x4 models from 18 mpg on the ’03 Explorer, and 20 mpg for 4x2 models from 19 mpg on the ’03.
quote:
quote:Are these figures Imperial or US?
Fuel economy for the most popular ’04 model – the 4x4 with V-6 engine – is expected to increase to 20 mpg from 19 mpg on the ’03 Explorer. Fuel economy for the base model (4x2 V-6) will increase to 21 mpg from 20 mpg. Similarly, metro-highway fuel economy for Explorers with the optional V-8 engine will increase to 19 mpg on 4x4 models from 18 mpg on the ’03 Explorer, and 20 mpg for 4x2 models from 19 mpg on the ’03.
They look US based on what I know about SUV's from my brother in law... (he is an Explorer Lemming

ErnestM
quote:Come on Manek - that's mere sensationalism. You know better than that old bean - Real Time Systems are designed/produced in an entirely different way than consumer software on which there are no safety dependencies and no failsafes.
Then all will take is one bug in Windows 2015 and the whole car shudders to a halt.
Anyway, they've been testing this sort of software in Airbuses - all the crashes are out of the way now

Don't forget all those F1 cars that use electronics in between pedal and engine, and look at how well tested and reliable they..... oh, hang on a minute...
To be fair, most faults related to software control usually result in the car not moving in the first place (Spain 2001?), which is a pretty fail-safe mode, unless you happen to be sitting on an F1 grid on a Sunday afternoon.
At least computer control gives you more ways of coping with failure - if your throttle cable snaps or the pedal jams, there's not much you can do about it. Taking the example of F1, our cars (I know, BAR isn't perhaps the most shining example of how to win races!) have a mode where the throttle pedal basically becomes an on-off switch if the position sensor in the pedal fails, so you can at least carry on. Of course you also need to have the driving abilities of an F1 driver to cope with that mode - anybody fancy that happening to a Griffith on a wet road?!
To be fair, most faults related to software control usually result in the car not moving in the first place (Spain 2001?), which is a pretty fail-safe mode, unless you happen to be sitting on an F1 grid on a Sunday afternoon.
At least computer control gives you more ways of coping with failure - if your throttle cable snaps or the pedal jams, there's not much you can do about it. Taking the example of F1, our cars (I know, BAR isn't perhaps the most shining example of how to win races!) have a mode where the throttle pedal basically becomes an on-off switch if the position sensor in the pedal fails, so you can at least carry on. Of course you also need to have the driving abilities of an F1 driver to cope with that mode - anybody fancy that happening to a Griffith on a wet road?!
quote:
At least computer control gives you more ways of coping with failure
Completely disagree, a cable snap is simple and usually repairable on the road side. A quick trip to a local garage or carrying a replacement is not hard. (real emergancy. attach the cable and hand throttle, or simple fix it open at about 2k revs. (it will get you home). Carrying the personal computer needed to be able to check what the little black box is doing is a little harder. AND i'll put money on that you won't be able to buy the software cheaply. No this is another "garage will be the only way to fix it" (=expensive bill) and really not that beneficial.
Seems to me the 1% fuel saving is just obtained by smoothing out acceleration, ie making it even slower.
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