Thermal Cameras - any joy?

[CWA]

Inspired by an old video posted by Pat a while ago, I'm looking into getting hold of an FLIR / thermal camera for seeing the spread of tyre surface temperatures during driving. This will be either in addition to or instead of a home-brewed thermopile IR sensor rig, depending on funds available.

Has anyone else on here had any luck in getting hold of a thermal camera? If so, which hardware option did you go for?

With cost the biggest barrier, the biggest question in my mind is, can something like this (http://www.ebay.co.uk/itm/271767149273?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT) which is made for smart phones, be interfaced with on something like an Arduino to gather and store the data. I wonder if anyone has considered doing anything like this and had any success?

[BillCobb]

http://www.ebay.com/itm/FLIR-ONE-for-Apple-iPhone-5-5s-/151558539181?pt=LH_DefaultDomain_0&hash=item234997c7ad

Put this on your Phantom Vision 2 Plus drone and sniff out your tire temps.

[Goost]

How about an array (16x4 pixels) instead? Will you use the full field of view?

http://www.melexis.com/Infrared-Thermometer-Sensors/Infrared-Thermometer-Sensors/MLX90620-776.aspx

or already on a breakout board (first link I found)

http://www.robotshop.com/en/thermal-array-sensors.html


Anyway, a thermal array sensor may be cheaper than a full 'camera'?

[Claude Rouelle]

Nice but besides visual appreciation, what do you with the collected data? Can you record it? How do you analyze them? What tool do you use to make the data USEFUL? How does this help you to design / develop a better car?

[CWA]

So we want to measure dynamic tyre surface temperatures primarily as a learning exercise (learning to develop the car, and our own knowledge). We want to see how vehicle setup (cambers, pressures) correlates with tyre surface temps / spread and correspondingly how this correlates with lap time/vehicle performance. Hysteresis loops in measured tyre F&M data often show that instantaneous temperatures of the CP rubber can alter grip levels quite considerably. Something we want to explore is whether this can happen mid-corner, whether temp increases during a corner/skidpad event can cause either an increase or decrease in grip levels.

Existing IR video footage of other tyres allows us to conclude that measurement of the CP rubber in the pits (via IR) is a pretty flawed exercise, as CP rubber temperature seems to drop within a matter of seconds once the tyre stops producing grip. We still plan to measure carcass temperatures with a probe in the pits, as we understand the temperature drop-off takes considerably longer in this case. But we have a feeling that carcass temperature is linked more with cornering stiffness and other 'handling' attributes of the tyre, investigation into which will be a separate exercise.

At this stage Claude, a thermal camera is still just an option I want to explore, and I'm trying to find the cheapest way of utilising it, hence the post. I'm still trying to work out how much time/money I could afford to spend on sensors, and what useful data I can afford for such a system to provide me. I want to explore whether a thermal camera will be the lowest net impact to the team resources. For example, if we have money available, but nobody capable of/with enough time to design a sensor system, a thermal camera will require a lot less work to get useful information from, and if the above option (smartphone-integrated) is viable, not much more money either.

Some more benefits I had considered a thermal camera to hold over an IR sensor rig:

- The camera will more easily show deltas across the tread width, and allow us to take a migrating tyre tread into account more easily. Is there a peak in temperatures across a certain part of the tread width that the mere 3 sensors I can afford cannot pick up? Would I only benefit from using a minimum of 6 sensors on a tyre for some tests?

- We can focus a camera at the contact patch and gain an idea of the temperature change from contact patch to ~180 degrees later around the tyre circumference. This would cost more sensors to verify without a camera.

- Camera footage could help to verify any issues that arise during the event, did we drive through some water / shade / grass here, which is why temperature levels changed?

- It's cool - not to be underestimated, a big factor in getting other people interested in the work that has to be done. The video footage is a great way to present results of testing / development to the people who fund the team. In general, perhaps video footage is less easy for other team members to dispute / draw the wrong conclusions from.

Added - *As I think you are alluding to Claude, we may have more trouble gaining accurate values for absolute temperature using a camera. My first thoughts in this regard though, based on what we want to achieve, lead me to believe that deltas are more important to us - deltas across the tread width, deltas with time/between corners, and deltas between vehicle setups. Acceptable errors in predicted / actual values of absolute temperature could be on the order of 5-10 degrees? Maybe absolute temperature values aren't even important? I'm not yet sure how well a camera will visually depict the range of temperature deltas that we will be interested in, that's something else for me to think about. But if deltas are all we are considering, can't this be done purely visually using video footage, without having to post-process what the video shows into numbers? If we were gathering numerical data, we would post-process this into a 2D graph to show trends, but video footage already shows us these trends rather well. In any case, carrying out some kind of exercise to 'calibrate' our video footage to give accurate-enough absolute temperature reading might be easy enough.*

And now the plot has thickened further for me, Goost's sensor array looks like another hardware option I need to explore, perhaps it will be a happy-medium. In the mean time, I'd appreciate hearing from more people about their experiences with this kind of DAQ, or any other thoughts.

BC, I'm still working on gaining budget approval for our on-event TV/support crew. Apparently this guy is unavailable - https://www.youtube.com/watch?v=w0nH7FLuZNw

[Claude Rouelle]

CWA,

I get that. If the inside of your tire is red and the outside is blue you have too much camber. If the tire center is red and the outside and inside are blue you have too much pressure. But that is the obvious and easy part. No need for a PhD to get that. But the reality will not be that simple. You will need to go further than a simple qualitative and temporary analysis. Think about the "movie" more than the "picture"What if your tire inside is light blue and the outside is dark blue at the entry of a corner and the inside id red and the outside in yellow at the corner exit? That is just one example.

What I was trying to have you guessing in my previous post is: Can you make a qualitative and QUANTITATIVE association with your colors and your change of colors with the variation of camber, pressure, vertical load, slip conditions, the tire graining measurement etc...? If you can'i your IR camera is just like a toy: Amazing the first day but you will leave it aside just a few days later because beside the obvious it won't help you much. There are software that helps you to make the color and color changes analysis useful.; Or you can create yours. You need to push your research further

[CWA]

I get that. If the inside of your tire is red and the outside is blue you have too much camber. If the tire center is red and the outside and inside are blue you have too much camber. But that is the obvious and easy part. No need for a PhD to get that. But the reality will not be that simple. You will need to go further than a simple qualitative and temporary analysis. Think about the "movie" more than the "picture"What if your tire inside is light blue and the outside if dark blue at the entry of a corner and the inside id red and the outside in yellow at the corner exit? That is juts one example.

What I was trying to have you guessing in my previous post is: Can you make a qualitative and QUANTITATIVE association with your colors and your change of colors with the variation of camber, pressure,vertical load, slip conditions, the tire graining measurement etc...? If you can'i your IR camera like a toy: Amazing the first day but you will leave it aside just a few days after because beside the obvious it won't help you much. There are software taht help you to make the color and color changes analysis useful;or you can create yours. you need to push your research further

Thanks Claude, I appreciate the insight and direction. Perhaps I need to confess, so far I've not even experienced this 'easy part', let alone anything beyond it, neither has my team. Purchasing/making some kit to log tyre temperatures is supposed to be the first step.

At the moment, this thread / my question is just asking for advice on hardware options to help me make this first step. I can't do the easy part, nor can I push the research further until I have some hardware and some data, can I?

Do you think I am trying to make a start to this piece of work in the wrong way?

[Claude Rouelle]

CWA,

You are going the right way but you only made 1 step; you need to go at least another 10 steps further in your research before you buy and use anything. You need to find out how you will make this data USEFUL. You need to look for Cases Studies made by people who went through the same issue before you. Most of the time the manufacturer of the hardware and software should be be able to help you with that. Otherwise it is just another monkey-see-monkey-do toy.

[Drew Price]

For a project at work recently we rented a hand-held FLIR brand IR camera. There are lots of companies that rent industrial test equipment, you could probably get a demo unit comped if you plan your testing out pretty well. I believe it cost us ~$40/day to rent, and it'll log peaks and screenshots for later analysis.

[Claude Rouelle]

"...for later analysis." That is my question: what kind analysis do you plan to perform? How will that help you you to get a better car?

[Kevin Hayward]

Depending on the cost/availability of the camera I wouldn't discount the value of play. Sometimes just seeing what you get will prompt you to figure out ways to use it. There are plenty of studies that relate learning to play (i.e. play is not just for kids). My personal favourite is to try different manufacturing techniques. You make a lot of mistakes and most of what you try leads you nowhere, but every now and then you get a real gem.

Just try and keep the playing affordable. A rented camera for a day sounds like a great idea. Either that or request a demo from a supplier before purchasing. Have a look at temp distributions around brakes, engines, driver, tyres, radiators, oil system, parts during machining, temperature distribution on composite parts during curing.

Frankly if you couldn't find value in using a FLIR I would be surprised. The tyres would be just one area to look. I wouldn't be doing it too much for hard data, but it could greatly increase your understanding of tyre behaviour in a very short amount of time, just by reviewing a lap of footage. If you did want to do harder data analysis then Matlab has some very powerful image manipulation tools available.

As engineers it is very important to develop a broad understanding of potential solutions. Looking at videos and pictures is a poor substitute for hands on learning.

Kev