My car, along with a few other models, and most new trucks and buses, use a drive-by-wire system.

That means, there is no direct link between the engine and your right foot, just a computer deciding engine power based on the position of a sensor.

I propose creating a digital mapping system that would allow the user to select one of several predefined accelerator position maps.

As the sensor is moved through it’s arc by your foot, these maps would be automatically applied.

For example, you could select soft – meaning a nice exponential response. Or normal – a linear response. Or hard – an inverse exponential response.

This system could easily be retrofitted to existing DBW accelerators.
-- TIB, Sep 15 2003

Okay, but not on-the-fly. A different preference can be remembered for each driver, but each driver must change his/her setting by stopping the car and fiddling with something under the hood/bonnet.
-- phoenix, Sep 15 2003


jezz TIB, you've been throwing out ideas like crazy
-- dickity, Sep 15 2003


Hey [dickity]: Yeah… I’ve got to back off. Don’t want to annoy too many of the oldtimers here. Most of these ideas are off the top of my head as I read other people’s much better thoughts; all my really good ideas reside in a stack of notepads.

[phoenix]: Agreed. Changing the mapping on-the-fly could be deadly.
-- TIB, Sep 15 2003


[TIB] attach it to a memory button like the seat position (or link the two together). Or get really wild and implant an RFID chip in each drivers car key, and when they get in, the car just responds by changing everything to fit that driver's profile.
"Honey, just popping out, mind if I borrow your carkeys?"
"No, but be prepared to steer with your balls and accelerate with your big toe..."
-- goff, Sep 16 2003


don't the engineers at car companies work very hard at making throttle response linear; through transmission gearing , computer control, etc....

why wouldn't you want a linear response in a car ?
-- SystemAdmin, Sep 16 2003


Hi [SystemAdmin]:

There are a few reasons I can think of for wanting to have a non-linear response to accelerator input. Fuel savings by having a greater range of control when starting from a standstill; more power off the line when you want it (good for twisty roads); a linear mode for when others borrow your car. After experiencing cars that have all three responses, I’d have to say that the parabolic response is my favourite (slow at first, then increasingly faster).

My old car, a Cavalier with a 150 HP HO engine, was extremely touchy. The slightest depression of the accelerator pedal would result in it leaping off the line. It seemed to me that GM probably engineered this in to give customers a feeling that this car had more power than it really did. Really, all it did was use more fuel and rubber.

My latest car, a Golf TDI, is the opposite. I have to push the pedal at least halfway down to get the thing to move. Now that I’m used to it, I much prefer this, as I have much more control over the engine in the range that I use 99% of the time.
-- TIB, Sep 16 2003


how about steering too.. more range of motion for city driving and precise control for high speeds.
-- kumpf, Sep 16 2003


150 HP seems pretty low these days. It was actually, as far as I know, a derivitive of the quad 4 engine (4 cylinder HO).
-- TIB, Sep 16 2003


Variable steering has been done by several manufacturers.
-- random1, Sep 22 2003


Sort of baked by cars that have an economy/power modes.
-- PiledHigherandDeeper, Sep 22 2003


the reason you have a pedal is to control power. some may be more linear than others but i think if you want to accelerate out of the turn impulsively you dont want to have to scroll through you premapped library of advanced pedal techniques.no turning back for those undicided mothers who want to acclerate there babies in to the lake though
-- mini1, Oct 13 2003


Baked. Already done. many manufacturers use this type of arrangement. Most all vehicles now utilize "programmable" mapping for the engine management. It adapts to the drivers habits and makes adjutments to the mapping accordingly. There is even modes that can be set that will limit or increase the power available through a drive by wire system (valet mode, teenager mode, sport mode etc.) The drive by wire system is also used to "back off" the throttle when the traction control system activates. This prevents a stupid driver from applying more throttle input as the vehicle is attempting to correct itself and regain traction.
-- bender, Oct 16 2003


the stratigys used to adapte to driving styles is very limited and based on the amount of time the driver exceeds some set of perameters set in the mapping for the engine management and the tranmission, if the engine is at full throttle for a period of time the transmission control unit will shift at a later point, if the driver starts driving normaly the control unit count back to a normal shift point with in a matter of seconds. The only long term adaptations that take place in engine managment have to do with emissions and internal transmission wear.
-- calex, Nov 27 2003


Also kinda baked in older electronic ignition systems (drive by metal wire?). The injector pulse and timing can be altered to limit engine power. In some cases there's a motor than has limited throttle override too. For example, when the engine's cold, even if you stamp on the pedal the takeup will be restricted.
-- Jim'll Break It, Mar 23 2005



random, halfbakery