cyotani

iTrader: (8)

I am currently developing my own custom data acquisition system to be used by my school's formula SAE team and after my Miata. I just want to document my build here and get feedback from the community on what features would be useful to the weekend track racer and get ideas for future additions to the systems. I am going to be 100% honest that I do not know a whole lot about processing this data to fine tune a vehicle. At the moment I am focusing on the hardware and software and getting useful data that is accurate and at adequate data rates.




The hardware:
National Instruments MyRIO (NI myRIO - National Instruments)
-Xilinx FPGA and dual-core ARMŽ Cortex™-A9 processor
-10 analog inputs, 6 analog outputs, 40 digital I/O lines
-onboard accelerometer
-wireless communication (stream information to any windows comp or tablet)

GPS module using UART communication
Infrared Temperature sensors using I2C
LCD screen with I2C interface
CAN bus module using SPI module
ADC expansion modules using SPI

The software:
Labview - with real time and FPGA and other add ons
Diadem - for data analysis and data reporting

Data Channel capabilities:
All ECU data via CAN communication (in development)
Infrared temperature sensor arrays (done)
Accelerometer (done)
GPS (coordinate log done, possible live map view in the future)
Temperature data via external ADC with bridge and up amp circuits (not started)
Pressure sensor via external ADC (not started)
Strain gauge force measurements (done)
Wheel Speed Sensors (not started)
Linear potentiometers for suspension travel and steering angle (not started)
Synchronize Video files in Diadem (in progress)
Acoustic Octave Analyzer (done- required per FSAE rules, useful for tracks like Laguna Seca)


Control Sysren Ideas
Active Aero


I can easily create open loop or closed loop PID control systems with any of the sensor data I am capable of logging. This can make for some neat projects down the road when I have a reliable core system developed. Simple ideas is programmable warning lights and actions (ie: warning light on display if coolant temp over x1, loud buzzer if coolant temp over x2, shut off engine is coolant temp over x3). a more complicated idea would be active aero based on throttle, steering, speed and accelerometer inputs. Let me know if you have any idea for projects.


Diadem Data Viewer example:


tire temp accel and gps testing


strain Gauge User interface:


strain gauge data for one corner Suspension set


Tire contact forces extrapolated from strain gauge data in the above pic using 3D vector Statics.


example labview programing code. pretty huh?


custom hardware enclosure:




Sure have come a long way from the early prototype stages of straping my macbook to the fsae car. lol. I'm surprised that actually worked okay.




PS: I recently purchased a 3D printer to design and prototype custom enclosures and brackets.











Stay tuned for updates and feedback is always appreciated

acedeuce802

iTrader: (1)

Good stuff! We also find yaw rate beneficial. But then again, I'm sure yaw rate is a lot more critical to making an FSAE car fast than a Miata.

Congrats on the finish at Michigan, going to Lincoln again?

dcamp2

iTrader: (4)

Nice work. Is that blue screen the only user interface (other than lights/buzzers)?

I remember using labview in college... Not nearly as sophisticated as this looks though.

cyotani

iTrader: (8)

Thanks. Yup the team is leaving to Lincoln this weekend. I can't make this one because of work. Then we have one more in Germany

Right now, for the FSAE vehicle the LCD screen will be used just to verify that the program is running and display the file name of the datalog and simple stuff. It may later get built into a more sophisticated user interface.

For the miata I can stream data to a tablet or computer and build custom interfaces similar to the ones in the picture.

cjsafski

iTrader: (2)

If you decide to do a display I started using these:

Adafruit 0.56 4-Digit 7-Segment Display w/I2C Backpack - Yellow ID: 879 - $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits



Not the fanciest thing but bright and easy to read. Also talk through I2C. I am currently working on a gauge set using these and an arduino. Even though the arduino is not quite as powerful as labview, I kind of like using it instead. Probably because I hate the kidpix style of programming in labview and when you make modifications it can get messy. Also all my experiments run on labview so sick of decoding other peoples messy programs.

Reverant

iTrader: (10)

The problem with 7seg displays is that unless you put them behind a tinted glass, the segments that are not on are still visible under bright light and that makes them not so easy to read.

robertcope

I work at NI. Fun to see products being used like this!

robert

Leafy

iTrader: (1)

Oh labview. This brings back memories of determining the pressure inside a soda can with a strain gauge and other mildly amusing labs. Is the newer version of labview more stable? I had a few instances where I wanted to put my fist through the screen because it didnt save or something annoying a few years ago.

cyotani

iTrader: (8)

I guess that would depend on what I am trying to display. Price wise the LCD display I'm using was under $15 so I can display much more information with it. Practicality wise, when driving you don't have time to look down and read displays too often. Especially a digital display that refreshes too quickly. Most likely I will be using a tablet with a cluster of analog style gauges similar to tunnerstudio, with warning LED or buzzer and If I trigger a warning bring that particular gauge full screen on the tablet. Just ideas for now. Not set on anything yet. A shift light array would be a fun little project tho.

Arduinos are nifty for the price and have a huge support community and library's for sensors already programed making them easy to use. A lot of what I do is read arudino or C programing for a sensor then convert it into LabView programs. I prefer LabView because I can implement a sensor and user interface extremely quickly, and visually debug application. If you plan ahead and use good coding practices and sub-VI it is not messy at all and is very easy to read code. But the software and hardware price is no where near that of the arduino.


Nice, how do you like working there? I was kinda considering that company for a bit.


I haven't had many issues with it so far. Only problems Ive had was connectivity issues over WIFI. And programing the occasional infinite loop or something but no major bugs.

Seefo

iTrader: (5)

very cool. This was basically my senior design project. Yours is a little more "on crack" computing wise, but its way cooler.

what frequency are you running the GPS at?

cyotani

iTrader: (8)

What hardware and software did you use? The GPS is the pmodgps unit set to 1Hz with a 10Hz max. I haven't messed around with changing that rate but I think 5 Hz would be adequate.
Digilent Inc. - Digital Design Engineer's Source

I wish I did purely this as me senior design project. I did the stain gauge DAQ system as part of my project then Carbon Fiber A-arms and have since graduated but am finishing up this system for the FSAE team for our last comp coming up soon. Then it gets adapted for the Miata

Seefo

iTrader: (5)

we used an arduino (we did a lot of this on M16C initially, but swapped over), + an SD card shield:
4 turck speed sensors (wheel speed). We also used a 1GT honeywell sensor
3 MLX9614 IR temp sensors (wheel temp: in, mid, out)
1 ADXL345 ( 3-axis accel)

This was for a Formula Hybrid team, so we also setup a voltage divider to get a general idea of battery charge. All the software was either open-source/shared code or written by us. We didn't setup anything special since .csv is widely accepted.

We had other ideas for stuff to do/add, but being a 14-16 week project including fabricating a box and doing the wiring, we were told not to. Probably a good idea, as we finished right on time.

JasonC SBB

Great stuff!

How do you mount strain gauges to read 3 axes?

cyotani

iTrader: (8)

Nice, I want to build a cheaper arduino based system for possible resell. It seems like no mater how much/little you do, senior projects always get finished right on time.


FSAE vehicle suspension consist of 6 tubes per corner which are all in theory axially loaded. So I can back calculate 3 axis tire contact forces and moments, using those 6 gauges (6 equations 6 unknown 3D vector statics problem).

Unfortunately this type of analysis is not possible on the Miata since the control arm members are not in just simple axial loading.

Seefo

iTrader: (5)

F1 teams use 6-axis F/T sensors during some wind tunnel testing. A company I used to work for supplied Sauber with them.

UrbanSoot

iTrader: (24)

Do you have any pics of the 7 segment displays mounted in the car? I was thinking of building an Arduino based dashboard for my car and stumbled onto the same Adafruit units as the only feasible solution with limited I/O channels.

cyotani

iTrader: (8)

My plan is to use a 4x20 LCD that can display 8 sensor readings on one display. This display is only $15 vs needing multiple $10 7 segments. However it is much smaller so I will be using warning lights and to tell me to look at the gauge for the issue when something goes wrong, rather than trying to have it big enough to glance down while driving on a track.

similar to this:

UrbanSoot

iTrader: (24)

Sounds like character display and warning light array is the best approach. I've considered using an RGB 20x4 display so it can flash different colors for different alarms or something.

cyotani

iTrader: (8)

I'm in the process of building a simple circuit board to power a few tri color LED's which I am planning to mount in the oem cluster. I'll post a video when I get it all finished up. A tri color LED with just 3 digital lines gives you 7 different colors which can be used for different warnings lights

b3d3g1

I thought many times about trying to put together an array of IR sensors for live tire temp data. It would be pretty cool to try it with a cheap IR capable camera too and get the entire tire surface and overlay it on video.

I've also been kicking around the idea of adding a heart rate monitor like they used to in F1. Found this on sparkfun that would be pretty easy to tie into my RacePack USM or any other analog input.
https://www.sparkfun.com/products/8661