How do the accelerometers work?
The ADXL202 units that we’re using are like minature pendulums. There is probably an app-note. • 2.5: How do angular rate gyros work? The Tokin gyros are a Piezo capacitive thingy. There is probably a better description somewhere else. • 2.6: What about magnetometers? The traditional magnetometer is a coil and has an induced charge from the earth’s magnetic field. I’m not really sure. • 2.7: Can I deduce attitude from magnetometers? No. Aaron wrote a better answer in the autopilot-devel archives that should be included here. • 2.8: Why the rate limitations? The angular rate sensors that we’re using are limited to +/- 90 degrees per second. We’ve amplified them so that we can sense +/- 30 degrees per second very accurately, which should be fine for the pitch and roll axes during a stable hover. Forward flight should also not experience dynamics much faster than that. The yaw gyro may, so it should have its own scale factor. 3: Kalman filtering • 3.1: What does the Kalman filter do? The
