Stuff related to MAV's (and UAV's) from a hobbyist's point of view. Info

Autopilot module - revision 2

I just finished another prototype for my autopilot module. The biggest changes are:

  • SMD components!
  • Runs on 3.3V: more sensor stability.
  • Possibility to use an external crystal instead of the internal oscillator.

The software is finished for about 80-90%. For the moment it looks promising. At only 8MHz (that only 2MIPS!), the module does the following, 50 times per second:

  • Decode (and glitch filter) PPM pulse train from RC-receiver.
  • Send PWM signals to the servos.
  • Sampling of the sensor values and filtering them with a 4th order runge-kutta filter.
  • Decode GPS input at 2Hz.
  • Kalman filtering pitch and roll.
  • A simple PID algorithm for stabilization.

Looks nearly finished… however, testing in a real MAV and finetuning everything will take a lot of time!

28 December 2007, 14:54 | Link |