Automatic scale car wash with shape profiling

Hey guys, I'm working on this project, and my issue is that I would like to integrate a system where some sensors would read and profile (if that's the right word) the shape of the car in 2D, so that I could run a rotating brush along that shape, and each run would be personnalized according to the car. Something like in this video :

So, how exactly can I do that? I'm fairly a beginner with Arduino, but do have some experience with PLCs.

Any help is appreciated.

Thanks!

Buy that toy from Fischertecnic. It's a huge and complicated project. Why invent the wheel again?
Make a visit to a commercial car wash and study the sensor set up!

It looks like there are two beam-break sensors mounted one above the other. I suspect that the lower one is normally in the shadow of the car and the upper one is clear of the car. If the upper beam is broken the machine must move up. If the lower beam is cleared the machine must move down.

...R

davidb36 Thank for that! Lovely piece of kit!
++Karma; // For showing me something interesting.

I do have some experience with PLCs.

In that case forget the Arduino for now and work out how you would do it with a PLC, then, if you want to do it with an Arduino you should be able to modify the design to work with one.

PerryBebbington:
In that case forget the Arduino for now and work out how you would do it with a PLC, then, if you want to do it with an Arduino you should be able to modify the design to work with one.

Although I could use a PLC, I'm still not sure how I would program to whole thing using ladder logic.

Robin2:
It looks like there are two beam-break sensors mounted one above the other. I suspect that the lower one is normally in the shadow of the car and the upper one is clear of the car. If the upper beam is broken the machine must move up. If the lower beam is cleared the machine must move down.

...R

Even if that is the case, how would I "draw" the outline of the car, and how would I make a brush follow that outline afterwards?

davidb36:
Even if that is the case, how would I "draw" the outline of the car, and how would I make a brush follow that outline afterwards?

Record the X and Y coordinates for each point at which there is a need to change the vertical position.

I'm assuming that the units of measurement will be steps moved by stepper motors.

...R

Although I could use a PLC, I'm still not sure how I would program to whole thing using ladder logic.

On that I have no idea. Is your question about the mechanical and sensor set up to do this or the computation needed? I am thinking that the mechanical set up will be the same whatever kind of computation device you use. Also, the logic that goes into the program will be the same. The difference will be how it is implemented. As you obviously understand ladder logic (I don't) I would imagine it would be easier for you to work out how to do it in a language you know. I would approach this a step at a time, trying to get something simple working or even roughly working, see what isn't right then improve it. You have to break it into small parts and work on each one.

When you've done this please come back and show us!