i'm wondering if there wouldn't be more precice means of governing speed of a modern vehicle.... i've never used cruise controle and i think it wouldn't be much use unless you have a long stretch of highway. but it's an interesing concept. yet in theory wouldn't a system where you input i certain speed and let the vehicle worry about how to achieve and maintain that speed not be more efficient than stomping one's foot on a pedal and see what happens?
the speed could be adjusted on the fly like now but there wouldn't be a direct link between in and output... if would first pass trough a filter that decides what's best.
i'm not sure if it would be usefull or usable, and perhaps in the end it's probaly alreay going on in modern engines, but think about it.
you press the throttle and a secondary display shows the speed you want to attain. the engine can than use the most efficient and smooth way to attain that speed. everything would happen in an instant, so the feel should not be much different from a modern car. additionaly different driving presets could be set like city or highway.... the main benefit is that a same trottle setting would always resuly in the same speed, regardless of engine load.
of course this only works if the whole thing was set up for FE
anyway, perhaps i describe something that already largely exist... my car's 20 years old
Offroaders frequently add these for better control when moving very slowly in low range, typically using bike shifter parts mounted on the stick shift, with a cable running to the throttle body like the gas pedal or cruise does. Here's a how-to with a couple pictures
cruise control is currently the best way to maintain a constant speed. can you keep the same speed forever only varying between+-1mph? i doubt it...
i use it all the time, when im in a car that has it... extremely easy and it doesnt necesarily pedal to the metal trying to get up to its speed you set. it gradually does it. im currently installing it on my chevette and i should see even higher mpg once i get it working good and use it all the time.
most of them you can control how fast you want it to acelerate up to your pre-set speed (aftermarket that is)
The leg and calf muscles are too large for fine-inputs over long distances. It drives me nuts trying to get a TPS of 17 instead of 19 at cruise. That 2% can equate to a greater percentage of FE.
I'm intriuged by the idea of the potentiometer and throttle-by-wire as well (or even an aircraft or boat-style throttle. That would make it easier to have a fail-safe mechanism for throttle-cut on braking or evasive actions.
repete86 - the main thing I noticed is that its increased pedal position resolution makes it easier to get better mileage at lower speeds where the pedal is exceptionally sensitive.
theclencher - the rod is not physically attached to the pedal plate, it just presses against it. I can push down on the pedal with my foot whenever I need more power than the hand throttle is set for, just like you do with normal cruise control.
lunerhighway - I'm not using it to control speed, I'm using it to control fuel consumption (or more specifically for a specific injector pulse width) so the fuel burn remains constant while the speed (and to a lesser extant the mpg) vary with the road grade.
As far as panic stops, full hand throttle is only 1/3 of the pedal travel, so even at full (hand) throttle, the ICE isn't putting out that much power, and its easy enough to flip it back to its idle position with the same hand movement I use the move the gear shifter back to neutral in preparation to dropping into a lower gear.