Data Acquisition by Race-Technology

[Composites Guy]

We are looking into purchasing the DL1 system from www.race-technology.com (http://www.race-technology.com)

Do any of you have experience with this system? If you could tell us a bit about the good and bad points of the system we'd appreciate it.

Are there any other good systems for around 1000-1500 US dollars that have the same abilities of this sytem? (GPS, 2-axis accelerometers, Track mapping, 8 sensor input channels)

[Composites Guy]

We are looking into purchasing the DL1 system from www.race-technology.com (http://www.race-technology.com)

Do any of you have experience with this system? If you could tell us a bit about the good and bad points of the system we'd appreciate it.

Are there any other good systems for around 1000-1500 US dollars that have the same abilities of this sytem? (GPS, 2-axis accelerometers, Track mapping, 8 sensor input channels)

[flavorPacket]

I've had decent experience with AIM products, and they definitely have something that will meet those reqs in that price range. I forget the model we used to run (we have since switched because of a new sponsor), but it was similar to what you want.

[Dan Lentsch]

I dont think AiM Has gps... (please correct me if I am wrong!!) but Race-Technology is a pretty cool setup! I think we are going to be gitting the MXL Pro which includes a snazzy display and thier most data logging capabilities.

[JR @ CFS]

We had a lot of issues with ours (DL1) that ended with us giving up on using it this season. My previous experience with AIM was excellent, with plug and play capabilities and fantastic factory support...they dispatched an engineer to solve an issue we had identified with our system. Unfortunately when it comes to cost report, it needs to be included!

[js10coastr]

I've worked with both... you're really looking to just get your feet wet with a system either will do. However I don't really recommend either of them. The AIM system is a pain in the rump to use and the DL1 isn't much better. "Problems" and "issues" with data systems happen and is mostly due to user error (I did actually have to send a DL1 all the way back to the UK once though).

If you really want to do some engineering with data acquisition you'll need to step up to a Stack system at the least (MoTeC being the preferred sys). Or you can make your own.

One other thing of note is that GPS is nice, but there is a lot more useful data in four wheelspeed sensors.

[Peter]

I agree, the GPS system is nice, but the accuracy is in the same order as your track width, so that makes it quite useless. You can get more info from wheelspeeds.

Also look at the software, the AIM software is quite limited. (but it is free)

Peter
Delft 04FSUK, 06FSG

[Christopher Catto]

hey. just spotted this.

we use the DL1 on our race car but for the moment only used temp and press sensors for the engine. did install also damper pots but not fully used them due to lack of time.

our car is full size and 500HP though so things like GPS accuracy are not so critical. I would say though that we had some issue with speed trace not matching at the start and finish of the lap. we are investigating this if it is our mistake or theirs.

the support I would say is ok. we had the car wired up in england by Race Technology. The guy I usually speak to is Lorne Winborn and he can always point me to a colleague if he cannot answer some question of mine.

Cant compare the software with I2 or Toolbox because I have not used those much. The RT v6 is relatively simple and does what we need. surely it could be lacking in some areas but then you get more competitive you may either decide to bug them for more stuff or to try a more expensive logger.

i just configure different windows/layers so that one has some vital stats (like max kph, max latac, max negative G etc), one has a nice BIG map, one has some engine health parameters (oil temp graph and water temp graph, shame we do not run a lambda yet due to our engine having had some frequent exhaust and cat mods), one window then has stuff like damper pots and steering sensors. you can set up math functions in the same way as calibration (offsetting voltages etc). software is free.

I was a bit upset when my boss bought the RT instead of the Motec but then when i realised how much the software can do and how much I have forgotten since doing data logging, I said to myself: dont blame the hardware or software, just work hard on improving yourself.

The guys know who I am when I call, they remember the car so that helps. However, not having used it on a smaller vehicle and in full anger I would maybe stick to what other teams use. Not sure about Stack though. Seems like an odd choice for FSAE. I would stick with Motec or get some help from PI if you have enough people on your team to justify the effort and money.

i would not build my own data logger. have built too many things on my own or with colleagues and it always works out long if you have to make a car in 1 year. sure, the DL1 may not meet your requirements in full but making your logger does require some skill nonetheless! the guy who makes it will learn a lot but unless he leaves plenty of documentation (read: he is a team-worker, has good comunication skills, can write good reports with pics and descriptions, is not building the thing in a hurry!) the team may not learn so much.

my question to you: does the team want to do

a) formula build and learn
b) formula tune and test

depending on your aim, you can then work out where you put the effort. formula build, learn, test, tune, break, learn, build, win does exist but you have to sacrifice something (be it using some designs from old cars or simply not sleeping at night and somehow making it to the finish without dying of RedBull intoxication).

as usual, sorry for long post folks.

[kmrobinson]

We used a DL1 for some small scale stuff (no sensors) and it's pretty spiffy, but not very "Engineering Grade" as far as the sampling rate and accuracy of the data goes. For comparing drivers and observing behavior of the car over the course of a driving cycle then I'm sure it's good enough. For precise understanding of the variables involved in what you're doing, you might want to bump up to a vastly more expensive system.

Still, having some data is better than no data.

[Tim.Wright]

My opinion on the DL1 is here

http://fsae.com/eve/forums/a/tpc/f/125607348/m/93110196...10107041#24110107041 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/93110196041?r=24110107041#24110107041)

We've used it for about a year. A good system to get started with but very basic. Starts out cheap, but by the time you have made a breakout box to replace the crappy screw terminals and purchased a CF card and reader its not so cheap anymore.

Free software is very limited and the pro software is expensive. Luckily you can export the data to csv and do your post processing in matlab.

Tim Wright
Suspension and Vehicle Dynamics
Curtin Motorsport

[Composites Guy]

Could you clarify what you mean by the "pro" software for the DL1. They only show 1 (free) software package on their website.

Also, I understand that Data acquisition is partly what you make of it. We are prepared to write our own programs to analyze and think through the data. However, starting with good raw data is a must. I'm interested to know if the data that's collected (particularly from the GPS and accelerometers.) seems accurate enough for autocrossing. What is your impression of this?

For instance let's say we set up a constant radius turn and send the car around fast enough to be at the edge of lateral grip. If we do this multiple times varying tire camber angle, will we be able to record a difference in lateral grip on the accelerometer?

Also, is the track maping software good enough to say anything about the line that different drivers take through the course (or is the resolution too poor).

Are there any major flaws/problems with the DL1 that we should be aware of? How is there technical support?

[js10coastr]

AIM claims some pretty good GPS results. http://www.aimsports.com/weblog/archives/2007/01/

Those results have a lot to do with the algorithm used to determine the actual position.

You should be able to see a difference in lat G in your example.... however you could do the same with a stopwatch.

As an aside... lately I've been making more setup changes based solely on driver feedback. A lot of pro teams seem to work that way too, using the data system as an expensive warning light that can record top speeds and lap times.

Perhaps the "more correct" way of approaching data acq in FSAE is asking yourself "what do you want/need to know?" followed by "How can we figure that out?" and then buy what is needed.

[Tim.Wright]

Composites guy,

I have noticed RT don't mention anything about the pro software anywhere anymore. Maybe they don't do it anymore.

The on board accelerometers are good enough to pick small increases in acceleration.

The GPS is not good enough to compare different driver lines. Our GPS map 'drifted' about 5m during our endurance event last year.

I haven't really used the tech support so I can't comment.

Tim Wright
Suspension & Vehicle Dynamics
Curtin Motorsport

[Composites Guy]

thanks Timo!

[Mike Cook]

We had the DL1 and then traded in to get a DL2. It certainly isn't a PI box, but for our budget, it works well and haven't had any problems. My only complaint is having to take the flash card out to read the data. For us, the DL2 is behind the seat so getting to the card is a pita.

Also, the software isn't great, but you get what you pay for. I would say overall its a great setup for a fsae team.

[Composites Guy]

Thanks Mike!