Future cruise control


#1

In the past, cruise control was an option. It was a separate device or circuit added to the car upon purchase. Nowadays, I think it’s actually part of the car’s CPU.
Recently, I read a discussion about acceleration. Which saves fuel, slowly attaining speed, or rapid acceleration to get to speed quickly.
Could the cruise control be hacked (or redesigned) to allow for an automatic acceleration? When the light went green, you would flick a paddle, and the car would accelerate from zero to the speed required, using the various sensors to regulate for fuel usage. When you flicked it again, the car would maintain the speed in cruise. Everything would be overridden by the pedal or brake.

Comments?


#2

Mercedes, BMW, Audi, etc. have offered radar-based adaptive cruise controls for several years. They will follow the car ahead of your at a safe distance up to highway speeds, slow the car down to a full stop and proceed to cruising speed without driver touching the gas or brake.


#3

I think the best acceleration rate often depends on the length of the cruise period after the acceleration and there is no one best rate. I have gotten some of my best mpg results by accelerating surprisingly aggressively when I needed to accelerate. It’s not so much how hard you accelerate than it is how you manage to avoid superflourous acceleration. Accelerating towards red lights, no matter how gentle, is still superflourous acceleration.


#4

You have a version of that now, but the acceleration rate is not optimized.

If you are driving with the cruise set, you just tap the brake to turn it off, then hit resume when the light changes.


#5

The simple answer is yes. In addition, the GPS could pickup the location, compare it to the speed limit stored in memory, or on the internet for this location and stop acceleration when that speed is attained. Combine that with the radar to avoid a slower vehicle in front, sensors in the road bed to keep us in the lane and we can then ask the next question “Who is driving this thing?”


#6

twotone said: “Mercedes, BMW, Audi, etc. have offered radar-based adaptive cruise controls for several years.”

I’m not sure Ford fits into that level of “etc.”, but we ordered it for my mom’s 2010 Taurus. You could st it to 90; it would back off to match the car ahead of you. Boring, but slick.

(She also got the radar based rear-cross-traffic warning system).


#7

My cruise control does this. I’d guess that yours does too. Except you need not flick the paddel a second time. Just flick it up and it’ll graduallly accelerate the car to the most recent setting.

Ken, I suspect it is optimized for best mileage. I can tell you from experiene that it certainly isn’t optimized for fastest acceleration!

Oh, one more point; you are correct that modern cruise control is now part of the “CPU”. It monitors the Vehicle Speed Sensor reading and shoould the reading begin to drop it opens the throttle postion accordingly, which in-turn causes the injector pulse width to increase (the TPS and MAF signals are key variables in the “CPU’s” programming.


#8

Popular science did a test and compared different acceleration rates and found you can actually get worse gas mileage if you accelerate too slowly, something that my own results confirm.
To accelerate a 3000 pound car to 60 mph, your engine has to give the car 360,745 ft lb of kinetic energy. That amount of kinetic energy is exactly the same for a car that accelerated to that speed taking all day to get there. The notion that one can get around the engine having to supply 360,745 ft-lb of kinetic energy by slowly sneaking up on that cruising speed is as absurd as thinking your house will be cheaper if you take out the longest mortgage possible.
Accelerate like normal people do, if it isn’t ideal, it’s not far off. If you plotted fuel used to reach a certain cruising speed on a graph at different acceleration rates, you will likely see a very broad upside down bell curve rather than a precipitous dip.


#9

The odd thing about my car is that the fuel mileage doesn’t seem to fluctuate very much, no matter how I drive. So, I have fun with it once in awhile…well, ok, quite a bit
The only thing I noticed that increased fuel consumption was using my remote start during the winter months. I’ve pretty much averaged 14.5 mpg winter and summer, with my lowest being somewhere around 10mpg using the remote start often.
Maybe it’ll go up once I’ve crossed 5k miles, I dunno.


#10

I too enjoy my car…daily. I’ll leave the hypermiling to those so inclined.

I haven’t checked my mileage since my just-completed minor modifications referenced in my other thread, but I expect a slight drop overall. Added punch at WOT comes not really from the ability to draw in more air, but rather from the added gas that the “more air” brings into the cylinder with it. Unfortunately, my car is well accustomed to WOT.