Flight-Dynamics Data Logger
This page needs to be totally revised and merged with «Flight-Dynamics Model^/research/flying/» and «Genetically Programmed Flight-Dynamics Model for Machine Learning of Flight Control^/research/uav/» to reflect the nature of the work I'm currently doing.
For now, it somewhat loosely describes the tools I developed for collecting data for a flight-dynamics model that I used in Software Engineering recently, as well as for the «Three-Axis Electromechanical Flight-Simulation Gimbal^/research/gimbal», among other purposes.
This is the powered breadboard for the prototype of the data-collection device. I can't even count how many times I've used this thing — it's awesome. Unlike all my other projects, there's almost nothing to this one but a few smart components that communicate over a serial interface. In fact, the only analog component in the entire system is the 0.01pF decoupling capacitor between the supply rails in the upper left. I doubt it's even necessary because the components likely have their own.
The «GPS receiver^http://www.pololu.com/catalog/product/1249» is ridiculously small. I put it on a ribbon cable (red/orange/yellow/green above) thinking it would need flexible placement, but no, it picks up a signal from my basement.
For testing, it's connected through a «serial-to-USB converter^http://www.pololu.com/catalog/product/391/resources» to my laptop. Sadly, not a lot of machines have serial or parallel ports anymore. USB is great for many things, but nothing beats a direct connection sometimes, especially for low-level tinkering.
The GPS receiver has software for real-time updates. This is nice when there's a computer available, but for this project, I need a standalone system.
So I'm using two «serial data loggers^http://www.sparkfun.com/products/9530». One is for the GPS; the other is for the attitude-heading reference system described below.
For the GPS, it records gobs of data (time, latitude, longitude, speed, and some other stuff) five times a second.
The «attitude-and-heading reference system^http://www.pololu.com/catalog/product/1256» (AHRS) packs three gyroscopes, accelerometers, and magnetometers into an unbelievably itty-bitty package. Not only that, but it does all the sensor fusion and filtering.
It's connected through a serial-to-USB converter to a real-time display on the computer. Again, this is nice for development, but in a standalone system, I used another serial data logger.
Interpreting its data (yaw, pitch, and roll, yaw, pitch, and roll rate, magnetic x, y, and z, gyroscopic x, y, and z, and accelerometer x, y, and z) is challenging.
Both loggers write to their own microscopic 2GB flash cards that I then pop into an adapter and read on my laptop.