Drag racing timing program.

[plchacker]

Sounds like a fun event. Lots of drag strips are being closed because of noise. Nice of a town to allow a day or so for fun.


Your system looked like it was close to complete. I would have used AB stuff and RSView but hey it looks like you got real close. Excel is not too bad to deal with if you have the communications drivers.

 

[Philippe]

As I said in previous reply, I'm a newbie in PLC field. I have learn by what I have in hand so GE fanuc stuff was there. I don't know anything about alen bradley but I think they are too much expensive for low field application like mine.


Now, everytime I work on a project, I go for AD stuff. I don't have to pay 6758436289 distributor world wide if I can go on by myself with projects.

But yeah it was a fun events but now it's past because the ROI was not really good...for them.

Here is the link of the event:
http://cf.geocities.com/dragsderuestejustine/index2.htm

 

[Peter Nachtwey]

I wouldn't use a PLC for this.

What is the scan time?
What is the variability of scan time?
How much difference does a millisecond make to the measured speed?

I would use a Rabbit semiconductor board or a similar embedded system. I would use the fastest photo eyes.

 

[Philippe]

The scan time was near 4-6 ms. For the variability, I don't know but it was working well. Anyway, nobody knows it could have variability except me. Also, I think a variability of max 8ms wouldn't be a problem for that project so it was useless to told them so far.

I saw that, on the speed, it was... you know the resolution wasn't near perfection but it was working for us. Speed was only a number, it was count in the winning process only in the worse case of, let say a same estimated times and same reaction time, the speed would kick one off... I build the system so it would give me a winner anytime, any situation. I had 12 "imbriqued" conditions to choose a winner.

It was the biggest project for me to learn on. Some guyz that run drag racing events often,told me that my system was awesome for a kid that had never runned a drag race. I must say, I'm proud of what I've done.

 

[OkiePC]

What is the scan time?
What is the variability of scan time?
How much difference does a millisecond make to the measured speed?

I would use a Rabbit semiconductor board or a similar embedded system. I would use the fastest photo eyes.

That is exactly the first thought I had when I read the headline...

Good thing none of the racers know how slow or inaccurate the timing computer in use really was...

Not knocking the guy for what he accomplished, but I would not have touched this one with a ten foot comm cable...

Ignorance IZ bliss I guess...

 

[Philippe]

Anything was on DC current so the only limitation in times would be the plc so ms scan time wouldn't be a problem for that application don't you think? The time was count in 0.00X of resolution and rare are a race that came close to that in a street racing. And the program was build in a manner that each track would be check the most equally in the same scan time. In the staging process not, but in the racing progress (I mean after the green light), everything was count aside, like track one was timered just before track two in the ladder diagram and so on so... as far as I know, it was working great.

Yeah I know I have much to learn but that was my first a-to-z complete project. I have done all that I can.

 

[plchacker]

What is the scan time?
What is the variability of scan time?
How much difference does a millisecond make to the measured speed?

I would use a Rabbit semiconductor board or a similar embedded system. I would use the fastest photo eyes.

This brings up a very good question. CLX is the fastest but even with CLX you would need some very good programming to accomplish a full race. The Christmas tree/hole shot timer, total time, and the speed sensor could be set up as seperate tasks on selectable time. Obviously imeadiate I/O would be needed for the sensors and tree lights. This would be fun work, but I highly doubt the NHRA would be happy if everything depended on the PLC. There may be some timers that could do the nasty work, and allow the PLC to do the data tracking and HMI.

I love racing, so its tempting.

 

[CroCop]

Anything was on DC current so the only limitation in times would be the plc so ms scan time wouldn't be a problem for that application don't you think? The time was count in 0.00X of resolution and rare are a race that came close to that in a street racing. And the program was build in a manner that each track would be check the most equally in the same scan time. In the staging process not, but in the racing progress (I mean after the green light), everything was count aside, like track one was timered just before track two in the ladder diagram and so on so... as far as I know, it was working great.

Yeah I know I have much to learn but that was my first a-to-z complete project. I have done all that I can.

4 mS scan variablity would be a lot if you were to compare from run to run, so I do think it would be a problem for your application.