Determining the position/direction of an aircraft

I'm working in a project that involves gyroscopes...

I'm using Arduino and an ITG 3200 to read the data from the gyrosco开发者_开发问答pe. I get 3 values in deg/s for each axis (x,y,z).

My question is: How can I know the actual (physical) position or direction of the device (let's say an airplane). There has to be a math formula or something like that.

Using only the gyroscope signal (which you have to integrate numerically), you'll eventually run into trouble, due to drift. What's normally done is combining an accelerometer (for low frequency signals, i.e. drift) with a gyroscope (for high frequency signals). Here's a link few links showing more or less exactly what you want:

• http://www.starlino.com/imu_guide.html
• http://www.instructables.com/id/Accelerometer-Gyro-Tutorial
• http://www.starlino.com/quadcopter_acc_gyro.html

Also, see these StackOverflow questions:

• Combine Gyroscope and Accelerometer Data
• Integrating gyro and accelerometer readings
• gyro, accelerometer, magnetometer and Kalman filter
• How to determine relative position using accelerometer and gyro data

We are working on a similar problem.

We found this video on YouTube especially helpful, as it came with a paper as well as an implementation (which runs on Arduino):

http://www.youtube.com/watch?v=fOSTOnQzZCI

The paper and source code:

http://code.google.com/p/imumargalgorithm30042010sohm/

In our case (getting the orientation of a remote-controlled ball), we also had to include an accelerometer and a magnetoscope.