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    Posted: Mar/08/2009 at 5:37pm

I'm in the process of building a data acquistion system for our team and just curious what other teams have done/would like to do.

For starters I'm working on putting some thermocouples on our CVT and gear box.  Further down the line I'm hoping to outfit accelerometers, strain gauges, a load cell or two, linear potentometers and maybe even a gps.
 
Our daq system is a national instruments CompactRIO with various modules.
 
Does anyone else have a daq system? What kind of data are you collecting and how helpful is it?
 
Also, what kind of data would you like to collect if you had a daq?
Andy

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Post Options Post Options   Thanks (0) Thanks(0)   Quote TerpsRacing-Dan Quote  Post ReplyReply Direct Link To This Post Posted: Mar/08/2009 at 6:24pm
We have a DL2 from race-technologies.  Have collected pretty much all the things you are talking about except for thermocouples and gps. In addition we recorded engine and final drive speed to tune our CVT.

We've used this data to tune our suspension and prove design changes (such as using strain gauges to show lower loads in an old design vs new) 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Mar/08/2009 at 8:39pm
We have a DL1 from Race Technology.  Last year we ran Linears pots on our shocks, wheel speed sensors, intermediate rpm, and secondary cvt rpm (all rpm's are hall effect), engine rpm (coil wire), 3-axis accels, steering angle sensor on he column, brake pressure, throttle position(the last three watch the driver), and GPS.  We havn't done much in the way of strain gages or load cells but rather we dyno'ed out shocks and backed out wheel loads from the shock position numbers.  We also havn't done anything with temperatures but then we don't have a gear box to worry about and CVT temps havn't presented themselves as a problem.
 
Our main problem has been getting someone to consistenly use the system and become very familiar with it since it's not a trivial thing.  When we have taken data with the full system we've gotten good data that has helped us out alot, but keeping the system together and working is a challenge since we've had two different people running it so far and they have both left.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Mar/08/2009 at 9:59pm
Originally posted by CLReedy21 CLReedy21 wrote:

Our main problem has been getting someone to consistenly use the system and become very familiar with it since it's not a trivial thing.  When we have taken data with the full system we've gotten good data that has helped us out alot, but keeping the system together and working is a challenge since we've had two different people running it so far and they have both left.


I'm worried about the same thing since right now.  I'm the only one working with this daq and it is not easy to setup.  The main issue is that I'm building a custom system using ni hardware and therefore labview programming is required to do anything with it. 

Hopefully someone will take some interest in it when I'm gone since it has the potential to be a really sweet system.  In the meantime I'm going to try to document as much as I can.
Andy

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Post Options Post Options   Thanks (0) Thanks(0)   Quote jarmumd Quote  Post ReplyReply Direct Link To This Post Posted: Mar/09/2009 at 10:42am
We used a DATAQ DI-710 for a couple of our thesis work.  I posted a link to my thesis (a while back) which has pictures of how I integrated load cells into the seat belts of our car, as well as integrating accelerometers onto the driver and vehicle.  One of my SAE papers also shows how we mounted load cells to our shocks.  My thesis does not, however, have any good pictures of how we mounted the data acquisition device, so I am including those.  We mounted it just behind the front suspension box on some "L" tabs with a ratchet strap to hold it down.

Our data acquisition was mostly geared towards loads work, but there is no reason it could not be used for CVT / Drivetrain / Thermocouple or really anything else that uses voltage to make measurements.   The one thing it can't do is GPS, but if you want that it may make more sense to have a separate setup with a nice GPS on a ram mount or a active antenna connected to a small-form-factor board.

marc



Edited by jarmumd - Mar/09/2009 at 10:44am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Mar/09/2009 at 1:42pm
Originally posted by jarmumd jarmumd wrote:

We used a DATAQ DI-710 for a couple of our thesis work.  I posted a link to my thesis (a while back) which has pictures of how I integrated load cells into the seat belts of our car, as well as integrating accelerometers onto the driver and vehicle.  One of my SAE papers also shows how we mounted load cells to our shocks.  My thesis does not, however, have any good pictures of how we mounted the data acquisition device, so I am including those.  We mounted it just behind the front suspension box on some "L" tabs with a ratchet strap to hold it down.

Our data acquisition was mostly geared towards loads work, but there is no reason it could not be used for CVT / Drivetrain / Thermocouple or really anything else that uses voltage to make measurements.   The one thing it can't do is GPS, but if you want that it may make more sense to have a separate setup with a nice GPS on a ram mount or a active antenna connected to a small-form-factor board.

marc

 
I remember taking a look at your thesis.  There's a lot of really good stuff in it.
 
We're mounting our daq in the same way.  We have an ammo box to which we are mounting rubber dampers to the bottom of and all of this is strapped into a bracket behind the front suspension box.  I'm using rubber dampers instead of lining the box with foam since the cRIO produces a good amount of heat so I want it mounted to a metal surface to dissipate some of it.  I'll post pictures of the setup when I get it all together in a couple of weeks.
 
marc, do you have any pointers on what range load cell I should use for the shocks?  I want to make sure I get one that that won't blow up due to shock load.
Andy

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Post Options Post Options   Thanks (0) Thanks(0)   Quote jarmumd Quote  Post ReplyReply Direct Link To This Post Posted: Mar/09/2009 at 2:56pm
I'll have to go back and check (you would think I would know off the top of my head), but I'm pretty sure that I used the DSM-2.5K Load Cell from transducer techniques:
http://www.transducertechniques.com/DSM-Load-Cell.cfm
It's 2,500 lbf, but it has an overload of 150% rated output, so it can withstand more than that.  If my old team hadn't taken everything apart so that noobs could drive a data aquisition car, you could see some picture of how it's put together.  Alas if you get the SAE paper referenced awhile back, it does have a picture of how we did it.  Essentially you make an aluminum adapter which you thread the rod into (and the spring sits on), and then you thread a stud into the other side which allows a female rod end to thread into.  This works pretty well, but you will need to raise the shock mounts on the car since you effectively add 2-2.5 inches of length to the shock.

i very much encourage you or anyone else to do this....  Really almost everyone does FEA wrong, and load cells are a great first step into integrating the proper loading into the frame for design.  Now correctly using that data is a whole nother story....   But please do this and feel free and obligated to ask me any questions about this.


Edited by jarmumd - Mar/09/2009 at 2:57pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote seanbronee Quote  Post ReplyReply Direct Link To This Post Posted: Mar/09/2009 at 10:54pm
Wow you guys are pretty hardcore-  Our telemetry, I was thinking we could put a switch on the gas pedal when the driver pressed it, (cuz really in these things the gas is either ON or OFF), a green light would light up on the top of a car so we would know when to cheer...
If we were living in a post-nuclear-war, dystopian society, with Mel Gibson tearing around in a tractor-trailer, a BAJA car would be ideal!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Mar/10/2009 at 1:55am
We poured a bunch of money into an ill fated telemetry system last year.   It worked well when we tested it before the race, but once everybody got there and radio traffic went through the roof we couldn't clear a signal over all the noise.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote johnpate01 Quote  Post ReplyReply Direct Link To This Post Posted: Mar/11/2009 at 11:18am
Wow, those are some pretty nice setups.  They are way above us, since we are a first-year team.  We did manage to get Garmin as one of our sponsors this year and they hooked us up with a pretty cool GPS system what allows one base unit to to record lap timing and course position data.  Its a 2-way GMRS radio too!  Its not anything special, but I think that it may suit our needs for now.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GT Steve Quote  Post ReplyReply Direct Link To This Post Posted: Apr/03/2009 at 8:58am

We have run a DL-1 logger for the past couple of years, and the 4th year itteration finially got us some useful data (after frying the logger with the Briggs alternator and having to get it re-worked by Race Technologies.  I wish I had some pictures of our electronics box, but it was basically a Pelican case with Amphernol bulkhead connectors, and it was pretty much water-tight.  We had good luck with the DL-1 putting up with the vibration and everything but dirty power.  We were able to log GPS speed and position (resulting in way cool track maps), 4 wheel suspension position (linear pots), 3 wheel speeds (rear spool), engine speed, steering position, brake on/off, and throttle position.  The fully functional version has only been running on the manual trans car, so we haven't had any experience useing the data for CVT tuning, but the shock data was very useful I've been told.

All that being said, I think its a good testing and tuning tool, but not worth the cost hit you take (our system came in at about $4K), virtually assuring a position at the bottom of cost.  We also attempted to run two-way telemetry (those from South Dakota may remember the radio mast on our trailer) but were never able to get the range we thought we should have.  As others have said, our 900 MHz radios probably just couldn't muscle through all the noise out there.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jarmumd Quote  Post ReplyReply Direct Link To This Post Posted: Apr/03/2009 at 11:05am
Seems to me that if it's race data you want, it makes more sense to run the system at one of the many scrimmages (winter baja, AU last fall) and then take it off so as not to take the cost hit at competition?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GT Steve Quote  Post ReplyReply Direct Link To This Post Posted: Apr/03/2009 at 1:20pm
That would make good sense, and I hope the current team has enough sense to realize that.  But unfortnatly i think the only guys who understood the whole system and know how to install it have graduated, so the point may be mute.
 
Hopefully they will have a running car to bring down to Auburn this next fall and can get some good information.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote toolbox Quote  Post ReplyReply Direct Link To This Post Posted: May/27/2009 at 11:41pm
We have an AIM MyChron4 data acq, but we haven't used it for a couple of years. I don't remember every getting anything useful out of it, but that's probably because the installation was janky. I'm thinking of having a few of the younger members put it on the new car and see what we can get and maybe try to better tune handling during testing. GPS tracking has to be the coolest thing out there, and can be done for cheaper than you may think:

https://buy.garmin.com/shop/shop.do?cID=142&pID=11039

Don't pay MSRP, Costco has these things on sale...

Garmin has their own (free) online analysis suite, and the unit has auto lap counting capability. Tracks can be imported into google maps and google earth to see where you've been and plan things out. The best thing is that it looks like a massive watch, and is not connected to the car - it's a "Driver Accessory."

For those of you running some kind of tracking during the Oregon enduro, what kind of lap times were you turning in if you don't mind me asking?

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Post Options Post Options   Thanks (0) Thanks(0)   Quote paasch Quote  Post ReplyReply Direct Link To This Post Posted: May/28/2009 at 12:40am
Originally posted by toolbox toolbox wrote:

We have an AIM MyChron4 data acq, but we haven't used it for a couple of years. I don't remember every getting anything useful out of it, but that's probably because the installation was janky. I'm thinking of having a few of the younger members put it on the new car and see what we can get and maybe try to better tune handling during testing. GPS tracking has to be the coolest thing out there, and can be done for cheaper than you may think:

https://buy.garmin.com/shop/shop.do?cID=142&pID=11039

Don't pay MSRP, Costco has these things on sale...

Garmin has their own (free) online analysis suite, and the unit has auto lap counting capability. Tracks can be imported into google maps and google earth to see where you've been and plan things out. The best thing is that it looks like a massive watch, and is not connected to the car - it's a "Driver Accessory."

For those of you running some kind of tracking during the Oregon enduro, what kind of lap times were you turning in if you don't mind me asking?

Mike

We've used a little two channel AIM for about 6 years just to tune the CVT.  Simple to set up and collect data on engine and secondary rpm.  We pull a signal off the ignition wire for the former, and use a magnetic pickup for the latter.  I would consider this the bare minimum for any team running a CVT.  

We've used National Instruments C-RIOs for complex mobile data acquisition, like accelerometers, strain gages, suspension pots and thermocouples.  The older ones are a pain to program because you have to get into the FPGA.  The newer ones are preprogrammed and a lot easier to set up.  Still, they're big and hard to mount compared to the AIM.  They also need water protection.

Our lap times at Oregon were all over the place depending on traffic.  Most were in the 4:00 to 4:30 range, with a fast lap of 3:45.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote toolbox Quote  Post ReplyReply Direct Link To This Post Posted: May/28/2009 at 2:12am
Interesting. After we got back out at the end of the race, there were a lot of slow or broken cars, so I don't think we had a good traffic free lap, but then again, neither did anyone else. Our laps were all over the place, with a fast lap of 4:12... Just guesstimating, I think we were at around 5:00 average. Passing was definitely an issue, there was a lot of single track.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ballast Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2013 at 8:29am
hi, i m thinking of incorporating a strain gauge or a proximity sensor onto the secondary pulley of CVT to detect when the CVT is actually shifting. Are there any better ideas of detecting the shifting of CVT?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote njgedr Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2013 at 9:09am
Not sure how a strain gage would tell you the amount of shift. I think the best method would be a hall effect or encoder on both the primary and secondary. If you really want mechanical shift instead of just speed difference lvdt or linear POT should work.
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Get the input and output shaft speed
The input is quite easy, you can get it from the spark plug wire
For the output, up to you, you can either use hall effect sensor on a gear or anything that looks like
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Post Options Post Options   Thanks (0) Thanks(0)   Quote lord2528 Quote  Post ReplyReply Direct Link To This Post Posted: Nov/04/2013 at 9:54pm
Do you know if there is a way to set up a live streaming to a laptop?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FredC Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2013 at 5:15pm
The short answer to your question is Yes, we did it. BUT it's really not an easy task, last year we had two or three electronic guys working almost all year on designing, building and programming our data acquisition system, we had live feed of our vehicle characteristics like speed, and other data. It's slightly harder than wiring two kill switches together.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RLM Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2013 at 5:29pm
never underestimate the difficulty of kill switch wiring at 4 am day 7 of being awake with 24 hrs till comp starts... we called an elec eng friend... never heard the end of it
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FredC Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2013 at 5:41pm
IF you have enough sleep, it's an easy task, well... even with no sleep it should be an easy task :P
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Richie_Dagger Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2013 at 11:01pm
Originally posted by RLM RLM wrote:

never underestimate the difficulty of kill switch wiring at 4 am day 7 of being awake with 24 hrs till comp starts... we called an elec eng friend... never heard the end of it
I thoroughly explained to two people how to wire kill switches and how they work, and they still tried to run it in parallel or something resulting in dysfunctional kill switches. It's as easy as engine > kill switch > ground, but I guess it's got to be more complicated than that for some.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cujdubs Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2013 at 11:15pm
I think for some the idea that you are intentionally trying to short out the circuit is hard to grasp. Our EE's usually decide that protecting the wires from abrasion adds far too much weight and it would be better if they shorted out on the firewall while in the tech line
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RLM Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2013 at 11:40pm
Don't get me wrong, we know how to do it, just at that state of mind with that lack of sleep that we were having difficulties... were all more mechanically inclined. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote njgedr Quote  Post ReplyReply Direct Link To This Post Posted: Nov/06/2013 at 9:36am
Briggs running like crap?

Step 1: Disconnect the kill switch connector from the engine

No matter how much effort goes into the damn kill switch circuit, it always found a way to fail. Even the kill switches themselves crap out.
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