Cruise control design. Look over my shoulder to prevent failure...

[tboydva]

kchriste, I"m on travel this week, so I don't have my service manual with me. What you're saying is what worries me. I was thinking about putting diodes into the current path to keep current from flowing where it shouldn't, but then you get some voltage drop so I would imagine it possibly messing up the throttle response. I think perhaps isolating the entire circuit with switches might be the best insurance. Still, I hear what you say about the current issue. As I remember the wiring diagram, voltage from the TPS/throttle "goes" directly to the vehicle's PCM. I would guess it should be high impedence if it's meant to monitor voltage? As you might guess, I've taken electronics courses, but don't have very much practical experience designing real-world circuits!

Thanks,
Tom

 

[Stellarcore]

Have any of you ever heard of the new adaptive cruise control that they are putting in luxury cars/busses?

Basically you set the maximum speed that you want to go, and it will adjust the speed below that point to remain a safe distance behind cars in front and will slow down to make turns. It detects vehicles in front through video cameras or in the more expensive versions radar. It also has a yaw sensor that detects whether or not the vehicle is turning.

Its a more complex system, but it would be really *really* cool if you made it work. =) I guess there are also many more possible points of failure, but its a neat idea nontheless.

 

[tboydva]

Stellacore - first thing's first! I gotta build the simple prototype first, then get fancy - I need a the noob version!

To answer some questions on the thread, here's the info on how the TPS/accel dictates the engine RPM:

See post #6:
https://www.powerstroke.org/forum/9...intermittent-throttle-problem.html#post141915

And post #10 here shows how you can alter throttle using a resistor and relays (like CydeKrash suggested):
https://www.powerstroke.org/forum/9...parts/9402-home-brew-high-idle.html#post89440

I need some deadline-less time and to be home to investigate further. I think I'll rework my design to incorporate ClydeKrash's suggestion of using switches (or relays like the idle mod) to isolate my whole circuit. Anything goes funny and the vehicle reverts to it's former self. I also need to tap the RPMs as a previous post pointed out - if it pops out of gear I could be screwed. My truck is older, but has very low miles, so I want to keep it running for a long time!

Thanks all. I'm sure I'll be working up potential circuits after Wednesday!

 

[philba]

Have any of you ever heard of the new adaptive cruise control that they are putting in luxury cars/busses?

Basically you set the maximum speed that you want to go, and it will adjust the speed below that point to remain a safe distance behind cars in front and will slow down to make turns. It detects vehicles in front through video cameras or in the more expensive versions radar. It also has a yaw sensor that detects whether or not the vehicle is turning.

Its a more complex system, but it would be really *really* cool if you made it work. =) I guess there are also many more possible points of failure, but its a neat idea nontheless.

what is really important about ACC is that even with only 20% of the cars on the road equiped with it, traffic jams will be significantly reduced. The reason is that ACC allows tighter tracking of the vehicle in front. Braking and speed-up have significantly less dead time. The typical rolling slowdown (standing wave) will be eliminated.