I wan to design a Collision warning system for car but I have no idea where to start and where can get the circuit diagram. I search in google but still couldn't find any circuit diagram. Help me!!!

 

Try googling for Proximity detectors for cars!!!

Mark

 

Or, try "ultrasonic parking." Got lots of good hits. John

 

What sort of collision do you need to be warned about? I think it was BMW that has this feature, standard... Pretty sure it was only for low speed, like parking.
For collisions at 70 MPH on the 'freeway' (not so free anymore), I'd imagine any electronic warning would be much to late, beside nobody would hear it over their cellphones anyway.

 

A circuit diagram won't do you much good without snesors and an understanding of the physics involved. Do you have either of those?

 

My group of engineers worked on this back in the early 1980s. It worked pretty well. One day on the test track some pigeons flew up in front of the car. The car locked the breaks and jerked the wheel to the left. The birds survived. The car went into the ditch and the engineers walked back.

 

Mercedes and other cars have a proximity detector that slows the car if the car in front is too close. Then it gets rear-ended by a huge truck!

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Uncle $crooge

 

Heck, just spend under $30 and get this ready-made one at http://www.opticsplanet.net/atnaut20bacs.html

I bought one for $22 from Overstock.com and it works pretty good. Wish I'd had it mounted on my high-riding truck before I backed on top of an Audi Roadster that was needlessly a few inches from my rear bumper!!!

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Don't make me reach through this monitor to slap you a good one!

 

I'd like to put that on my car with the speaker on the outside so people don't back into my car while I'm away from it. Maybe wire the 6-inch trigger to a timer that honks the horn for a set amount of time, like 1 second, to prevent it from honking the whole time.

 

Yeah there are many complicating factors. For example you may be driving down the main road and someone on a side street on the right crosses in front of you to go in the opposite direction. It is not difficult for a system to calculate range to obstacle and relative speed, but it is quite difficult for it to calculate the right-to-left motion and see that the car's going to be out of your path long before you get there despite the high closing speed.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

It's an annoyingly loud little piezo unit.... loud to the point that I mounted it behind the rear seat and stuffed a rag against it!! It should get attention if it was mounted exteriorly.

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Don't make me reach through this monitor to slap you a good one!

 

That's good to know. So overall are you happy with the unit? Thinking of getting a unit or two. My 67 fastback Mustang has very bad rear visibility and this would help a lot. For the wife's car, anything helps!

 

Seems to me that turns would be a prob too. I mean you could be going along a turn at 30 mph. If the turn is sharp, there may be a guardrail directly in front of you and closing on you at 30 mph, even though there is no cause for alarm. An understanding of the sideways motion relative to the car is again necessary.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.