Adaptive Cruise Control
Is OBD-II read only or can you also set values?
I was thinking of creating adaptive cruise control on my car. This would work by capturing the speed of the car in front continuously and then telling the cruise control to slow down if the car in front of you slows down (most likely i'll use ultra sound instead of laser).
So, what do you guys think? Can the cruise control be modified via my carputer?
While I love this hobby, and would be the last to stifle experimentation :
The absolute last thing I would do is give my car pc control of the vehicles rate of speed :-) Call me "old fasioned" but we all have seen those "that just cant be ?" moments when dealing with pc's and code where some extremely simple thing, which absolutely functions every time you use it, returns a value that is "wrong?".
I dont know what you are driving, but it would significantly effect the outcome of a "glitch".
In my "city car", a 95 Honda Civic with 4 cylinders that has a zero to 60 mph time of about three minutes (its so low its embarrassing when getting on the highway), if it decided that I should be doing 100 mph, I would have plenty of time to say "wtf?" and shut it off.
In the vette, if I was doing 60 and it decided I should be doing 100, I'd be doing 100 in less than four seconds.
GPS . . .great, where is a gas station . . .great, is it gonna rain . . .great, control of the accelerator . . .? . . .nah, Ill keep that one. Thanks :tea:
I'd love to see this! But only on YouTube! Hope you're not in my neck of the woods! ;):biggrin1:
Originally Posted by Sinabl
That is a very silly attitude, people. Half the functions in your car are already controlled by the car's built-in computer systems.
I agree that you should definitely NOT let your carPC have any control over the car's primary functions. You're running an OS, you're running other programs, you're running a computer with mechanical parts; there is simply too much that can interfere or go wrong.
However, I see nothing wrong with a hardware solution. You'd need a programmable microcontroller, some relays or actuators (depending on how your car is built), an input from the PC's OBD-II system for your speed, some hardware solution to gauge the distance/speed of the car in front of you, some electronics to prevent the system from sending out too high an accel signal (a potentiometer can let you set a higher signal on slow-accelerating cars, and lower on cars with a fast accel), and a killswitch wired to the brake pedal, ignition, the carPC, and a physical switch (just in case; and cause more buttons and switches always looks cool ;) ).
The only thing that prevented me from putting a working system together was the inability to find any sort of realizable laser/radar system to track the cars ahead of me.
Originally Posted by Banderon
To each his own, but I'm pretty sure I couldn't afford the insurance premiums.
I like the way Banderon thinks.
Adaptive cruise controls are already out there on luxury cars. My civic needs to be in that category as well.
The radar part is what i want help on.
I'm sorry guy, like I opened, I would be outta line offering a view that speaks to stifeling experimentation.
The baseline truth in what I was attempting to say seems to be mirrored in your reply (although I would think a purpose built, simple black box that controlled everything about the adaptive control, no os, no involvement with the car pc) would probably be the safest (read most reliable) way to go.
But by all means, have at it.:biggrin1:
One thing Brand, we call the modules in a car "computers" but they have more of a relationship with purpose built ic's than anything you would call a computer today. The majority of the "computer controlled" things in a car are a concert of very simple, specificaly designed, ic's that are hard coded, without an os. So they tend to work 1) pretty fast 2) "shoot it with a gun and it still works" reliably. They generaly work way above and below their design temps and they are set up to , by design, interact with each other to the smallest extent possible (so one system doesnt have to rely on another).
Originally Posted by Banderon
I dont know, some people here have some pretty impressive credentials (and systems), but Im not sure the very best of those systems even remotely approach the durability or reliability of what automakers put in production vehicles.
Just a thought.
Easiest way is just get a Lexus IS's Adaptive cruise system, and stick it in your car bypassing the CarPC. The IS is the smallest of the line that has it I believe. This is an absolutely awesome feature. Used it the other day in a friends GS on the interstate. Didnt have to touch the pedal from when I got on to when I got off. Always at a safe distance from the car ahead.
After the "gee whiz" factor wears off, Adaptive Cruise Control quickly becomes the most useless feature imaginable, IMHO. Do you really want to be stuck behind Grandma as she dawdles down the Interstate at 45 MPH? Keeping station behind a 62-MPH-speed-governed big rig is not my idea of a pleasant drive, but to each his own I guess. :D
Originally Posted by 2k1Toaster