Data acquisition post processing software

[Dave Harmison]

I just got my AIM EVO4 and am happily taking data.

I have been doing data acq of one sort or another for my entire 28 year career at Ford. Much of the post processing we do is in Matlab or similar high-end (expensive) software packages.

Can anyone recommend an affordable software package that would give me some of the functionality I am used to? For instance, I want to do more advanced filtering than AIM does. AIM does a simple time averaging and I want to do FIR and IIR filtering, calculate statistical metrics, etc.

I suppose I could try a student version of Matlab but I'm not sure what that limits you to and if it times out after so many months of use.

I've been spoiled by "Uncle Henry's" very deep pockets.

[SpacemanSpiff]

SciLab, it's MatLab for the rest of us. I think there are a couple others too.

As far as I'm aware my legally purchased academic copy of MatLab still works. Take that art class you've always wanted to take. Be a student again, it's good for you. Or just buy the package and have at.

[pier5]

You may want to try OCTAVE as well (it is equivalent to Matlab for free).
But if you intend to do signal processing on the acquired data, it is best done with the raw signal. I doubt very much that any logger will give you just that.

[Dave Harmison]

Thanks guys. Great feedback. Freemat, SciLab and Octave are the three I considered. I started in Freemat and quickly found it appears to not run very well. Maybe it installed poorly, but SciLab is running very well and I am writing scripts already.

AIM's documentation of what kind of data you are really getting isn't very thorough. I simply exported the "raw" data into csv files and am working from there. Is there anything not making that "raw"? I haven't seen anything discussing anti-aliasing filters or the like in the AIM documentation.

BTW: I called the AIM tech support line and unfortunately the guy didn't have much technical information. He didn't know what filtering "steps" are. Another racer told me that it is simply the number of samples for a running average "filter". Not elegant but ok for this level of equipment. Anybody know if that is really the case? I'd like to be able to put in my own filter coefficients but that is what SciLab will do for me.

What is GPS Gyro? I guessed it might be d(Heading)/dT but that didn't match very well. Again, tech support didn't know.

[Jean-Sebastien Stoezel]

Some GPS modules used for navigation have onboard IMUs that allow estimating and interpolating position based on actual movement of the unit, in between GPS updates. This allows higher "GPS position" updates. It's also used as an input to filter GPS readings and improve accuracy.

Or at least that's how I understood it.

What is GPS Gyro? I guessed it might be d(Heading)/dT but that didn't match very well. Again, tech support didn't know.

[Neil_Roberts]

Here's your AiM engineering guru:

http://www.precisionautoresearch.com...WeAre/PAR3.htm

[pier5]

Since I fix many data acquisition systems, my experience with the low cost type (such as AIM and the like), is that they employ very crude anti-alias filters (RC type) and whose cut-off frequency is very broad and not very sharp. They take care of the noise using simple averaging techniques (not moving-average, since this requires more memory) once the data is inside the micro-controller. The micros being used are not DSP engines either therefore this adds to the limitation of what you can do in real time before the data is stored in Flash memory or SD cards.

Basically what you are going to get as data is a bunch of parameters that went through some number of averages.

[Pi_guy]

Dr Dave
Is a really good guy, extremely helpful.
I enjoy every phone call I get to make to him, not always on topic but always educational!

[George Main]

I remember testing at Pheonix International Raceway in 1993, with Jaime Galles in Atlantic. We had wired up the Edge system and all the phone wire cabling that morning, as Jaime looked on.. We did a couple of sessions, and Jaime rolled into the pit lane and proclaimed that ATT had come on the radio wanting his calling card info....

[Brian C in Az]

Since I fix many data acquisition systems, my experience with the low cost type (such as AIM and the like), is that they employ very crude anti-alias filters (RC type) and whose cut-off frequency is very broad and not very sharp. They take care of the noise using simple averaging techniques (not moving-average, since this requires more memory) once the data is inside the micro-controller. The micros being used are not DSP engines either therefore this adds to the limitation of what you can do in real time before the data is stored in Flash memory or SD cards.

Basically what you are going to get as data is a bunch of parameters that went through some number of averages.

I am considering purchasing the TraqMate TraqDash system. I've been comparing it to the AIM system and the Race Technologies system.

Would mind sharing your opinion on these? The TraqMate only has 4 analog inputs, but it's price is quite a bit less than Race Technologies.

I'm open to other brands based upon quality and performance.

Thanks

[Pi_guy]

I am considering purchasing the TraqMate TraqDash system. I've been comparing it to the AIM system and the Race Technologies system.

Would mind sharing your opinion on these? The TraqMate only has 4 analog inputs, but it's price is quite a bit less than Race Technologies.

I'm open to other brands based upon quality and performance.

Thanks

Traqmate is for track day type cars.

Real race cars use
Motec
AIM
CDS
Race Technologies

& sometimes Pi systems if it came with the car.

[Brian C in Az]

Will you elaborate on that comment please?

[Garey Guzman]

Pi Guy,
You mention AIM but not Stack? Just curious why. (I've been gone for 5 years so a lot of re-learning to do)

Thanks

[romoman]

The Traqate software won't allow you to do any math channels, which in my opinion makes it a non starter from the beginning. It is also very limited to what it can take for external sensors and the wiring systems it uses are not nearly as durable as what AiM, MoTeC, or the other systems use.

I think at the pro level, you will only see MoTeC, AiM, and some CDS equipment.

[Pi_guy]

Pi Guy,
You mention AIM but not Stack? Just curious why. (I've been gone for 5 years so a lot of re-learning to do)

Thanks

Stack is mostly found in sedans have seen one or two vintage installs of Stack hardware in formula cars but have met very few that actually download the data. It is mostly used as a tach and oil pressure display. Have only seen one in the pro series in 7 years and the next year it had AIM in it.