Forgive me if this is not an appropriate place for this discussion. Most of my searches on this topic end up with hits on this forum so there seems to be lots of knowledge here. I am the DAQ lead for the University of New Mexico FSAE team seeking some information on displaying data from multi channel infrared tire temperature sensors.

I have been looking at the Motec dash loggers and really like them but we all know the costs are very high, especially if you factor in pro data logging.
I know I2 pro can display color contour maps as shown below, no problem.




I have also been looking at the AIM MXL2 as it has a very strong feature set, math channels, the whole bit, EXCEPT the ability to generate these contour maps of each temperature channel side by side. Unless I am mistaken this cannot be done in Race Studio 3. Is this correct?

The sensor is going to be placed either on our front wing, inside the side pods, or on the chassis for the front wheels so it will see the tires turning and flexing and I would like to create an image of the tire temp profile since the sensor will never be in perfect alignment.

As I understand it I can output a data file into matlab and use a script to create these plots. I am unsure how much pre processing this would require and I would like this data trackside ASAP for turning suspension and alignment. Any ideas on how to do this quickly?

I am kind of stuck here. I don't know that the Motec is worth triple the price to generate just this one type of plot.

Does anybody have experience with this type of sensor?
Can GEMS create this kind of data? Can AIM output easily to GEMS?

An example of a Matlab output and a F1 car below:






Thanks so much for your time and apologies if the non-Porsche content is unwelcome.

 

Welcome to Rennlist! AiM Race Studio can not do the colored graphs like i2 Pro. You can do a measured value on a track map, but it will only be one and in the shape of the track. When I display tire temps, I do them in regular graphs with all temps for one tire together so you can see the temp spread across the tire.

Which sensor are you planning on using? You can do this with the strip sensors (Texsense IRN-RC) as long as you have the strip angled correctly and then discard the unused signals when the wheel is turned. You can also use an IRN8C, but you will not have as many points and they will probably not all match when the wheel is turned. You can also use something like the First sensors, but those get hard to analyze when you have a 32x2 grid of temps.

Using Matlab will be your best bet if not using i2 Pro. I can't help with the scripting, but Matlab will let you do the most and give you the outputs you want in the format you want.

I would not say having the colored graphs is worth triple the price, but some might disagree. Either system will collect the data, so then it's about data visualization. You need to decide how you will look at this data and what you want from it to help with the car. From the raw numbers, you can check chassis balance, under/oversteer, optimal working temps, suspension setup, and quantify all of those. The colored graph can make it easier to see some of those things.

If you want wants some AiM files to work with I can supply them. I can also offer a FSAE discount to you and I sell AiM products and can help you with Texsense IR sensors.

Feel free to email me at matt@trailbrake.net if you would like the files.

 

Thanks for the info Matt.

I have been looking at the 16-channel Izzy Racing CAN sensors. He offers it at less than the 4 channel for FSAE. It looks pretty similar to the Texsense IRN8. I can ask you about costs offline. Either would work and the idea is to just make an "image" of the tire. You can see in the matlab generated image I posted that the tire is very visible even as it moves around.

The main goals are to see what peak temperatures the car is seeing, and how quickly it gets there. Then seeing what the gradient is to help us tune and verify alignment, corner weights, etc.

Our team has not been awesome with closing the design loop and test and tune in past years.

Anybody have experience with the GEMS software and how it compares to RS and I2?

 

I think the Izze Racing triple-in-one are the way to go. Use the 2nd CAN on an MXL2 and the Texense template and you're good to go. Each corner is a third the cost of the strips.

I have not had good luck with the GEMS software. I2 is the standard, RSA is 85-90% if your template requirement is supplied (you can make much more customizable, but not necessarily more useful for YOUR application, worksheets in i2 Pro).

 

Holy *****. I didn't know the Texense was so much more expensive. $300 for the 16 channel Izzy sensors seems like a bargain.

We are still in are initial design review phase, It's possible we go with the Motec, but I don't think they offer as much discount to FSAE besides being just plain more expensive. It should be a good investment for design report points as well as tuning for the dynamic events. It can also be passed down to other teams with only the purchase of new wiring harness and sensors.

 

Strips typically $1080/corner, Izze $399/corner.

I have supplied other FSAE teams with a MoTeC C125 with logging memory and with Pro Logging enabled. I believe the discount is 10%. There also may be a possibility you could use a CDL3 kit with Pro Logging enabled and end up spending not a whole lot more than a MXL2 and get the info you're looking for very easily, so don't blow off MoTeC yet...

 

Yeah I am just trying to present the best couple options and then the team can decide which one we go with and I will figure out how to integrate it as best as possible.

So far we are planning on doing the tire temp sensors x 4 (CAN), steering position, shock position x 4, brake position, wheel speed x 4(3? C125 only has 3 inputs which makes no sense), and then pulling the rest from the Motec ECU.

I have not looked into trying to get wheel loads from strain gauge/amp's but if we can integrate it for not a huge amount of money I would need inputs for that too. This may limit the use of the CDL3.

 

Pierre at Texsense has worked with lots of FSAE teams and offers a discount, though I don't know how much.

If you are good at MatLab, I think you will end up doing analysis there inbetween sessions.

 

Additional I/O are optional unlocks on the C125. ODU FSAE bought two C185's with all that and advanced maths! Sheesh!

 

I see what you did there...

 

Typically in a race car I see brake pressure x2 (front and rear circuits) since it's pretty easy to tap into and you don't have to worry about slack in the pedal travel and get the bonus of seeing balance as a math channel (which you can display real-time in an MXL2 dash, BTW).

The new systems all seem to have GPS for speed and internal lat/long acceleration, which means you'd only look at wheel speed to detect wheelspin or brake lockup, and not need to worry about tire diameter and changes due to pressure or wear.

One thing I have seen for belt-driven water pumps is an RPM sensor on the water pump to detect when the belt comes off and sound an alarm before the water temp skyrockets.

Sounds like a great project, Good luck!

 

I will look into the brake pressure transducers, that could be useful to verify the braking forces on the calipers and adjust the bias bar.

I am pretty sure I am going to try and include something like these Transducer Techniques Load cells that I can put inline on the push/pull rods to get wheel loads as well.

 

Hi,

You may want to look at: http://www.melexis.com/Infrared-Ther...90614-615.aspx

and just build up something...

Ray

 

It doesn't say what emissivity that sensor is set for...

 

Hi Matt,

The emissivity is user programmed into the device, or you can apply the corrections post collection. Device is itself temp compensated, and cheap!

BTW a fairly inexpensive brake pressure transducer is the BMW part used in their ABS systems... All this data can be gathered by something like a Raspberry PI, coupled with a GPS time stamp and then combined with all the other data...

Ray