IT ACTUALLY WORKS! This weekend, Aaron Kahn and I flew the
2.2 board on my Concept 60 helicopter. Unlike the past
few weekends of sensor calibration and data collection, we
turned on the autopilot software and it actually flew the
The first day we spent tuning the control loops to remove
oscillation in the pitch axis and slowly expanded the
control authority that the software had. We destroyed a CF
802.11 card due to vibration and had to stop for the day.
But it flew!
The second day we came back with new software that I wrote
the night before. This allowed Aaron to give attitude
commands to the autopilot rather than flight commands to the
servos. The standard helicopter is flown by directly
commanding the cyclic and collective (and throttle and
anti-torque and ...). If you hold forward cyclic, the
helicopter will nose over and do a loop or two before crashing.
With our software and hardware, he was able to instead
provide attitude commands with his joystick. If he holds
the stick full forward, it instead commanded the software to
maintain 8 degrees nose down. If he released the stick, it
would level out. Suddenly, it became a very flyable
aircraft, rather than an unimaginable nightmare to fly.
Next weekend we'll have the compass and GPS hooked up, which
should provide even better control. The GPS aided INS won't
be running, but we will have a working heading hold.
I've curated flight
data from Sunday and we have movies, too: