So I got some flight time under my belt yesterday. I must say there's nothing better than seeing your flying skills improve with time ( I can't wait to get more batteries so I can get my heli in the air as well). Anyway, back to the glider autopilot.
Managed to get the roll autopilot to stabilize the aircraft which was a great feat. Although because the glider is inherently unstable during banking (due to the battery pack sitting on top of the wing) the roll autopilot relies heavily in controlling the rates produced by the aircraft. This is still a problem as roll rate doesn't yet have a strong influence in the control loop.
The same can be said about the pitch controller (which I had to land the aircraft, upload new code and launch again). Due to the lack of control on the pitch rate, the phugoid mode of the aircraft is activated and the aircraft goes into an unstable dives which eventually would cause a crash.
The use of the safety switch mechanism logic has been essential in the testing of the controllers. It's quite clear parameter tuning through system identification is a sure way of reaching success than countless hours of mathematical modelling and controller design.
The next step is the use of gyroscope instead of differentiating the lagged acceleration-deduced pitch term to control the rates of both the roll and pitch controllers.
Flight test #3 to be executed soon...
Managed to get the roll autopilot to stabilize the aircraft which was a great feat. Although because the glider is inherently unstable during banking (due to the battery pack sitting on top of the wing) the roll autopilot relies heavily in controlling the rates produced by the aircraft. This is still a problem as roll rate doesn't yet have a strong influence in the control loop.
The same can be said about the pitch controller (which I had to land the aircraft, upload new code and launch again). Due to the lack of control on the pitch rate, the phugoid mode of the aircraft is activated and the aircraft goes into an unstable dives which eventually would cause a crash.
The use of the safety switch mechanism logic has been essential in the testing of the controllers. It's quite clear parameter tuning through system identification is a sure way of reaching success than countless hours of mathematical modelling and controller design.
The next step is the use of gyroscope instead of differentiating the lagged acceleration-deduced pitch term to control the rates of both the roll and pitch controllers.
Flight test #3 to be executed soon...
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