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Oct 19, 2007, 12:53 PM
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First auto hover video


Light wind returned, so we can pass more test flights.

The altitude anomaly was fixed. Only lucky timing jitter between GPS & INS readings kept it working before. Still pretty worthless in wind.

Amplifying the neural network predictions is required for flight. Straight predictions won't do it.

We're at the limit of servo feedback with these gyros. More servo feedback to handle wind is too unstable.

GPS acceleration is now lowpass filtered. It seems like it should improve results. Climb rate prediction in the desired range of velocities seems pretty worthless but manages 2 B just enough. Climb rate prediction is back to pure GPS, no accelerometer.

Finally was reliable enough 2 get video of an auto hover. The area for videography is particularly hard for autopilot. Seems 2 B a lot of wind in this area. Stabilization off camera concieled just how bad position hold was, but she retained control.

Successful autonomomous hover (1 min 34 sec)


Drift with the IMU and time needed to train the neural network combine to make success very hard. It usually takes a few tries before it works.

$225 vaporized. Moving on to better gyros. No inventory at Gumstix. The signs are pointing to better results being achieved from physics simulation in flight. Given current velocity, orientation, energy input, predict future velocity. The role of neural networks would shift to detecting wind or predicting energy conversion.
Last edited by Jack Crossfire; Oct 19, 2007 at 02:20 PM.
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