Thread: Build Log Asymmetrical UAV/AP
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Old May 01, 2012, 04:11 PM
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Originally Posted by Tom Harper View Post
1) Oscillation - It is critically damped in a right turn but oscillates in a left turn. Well, duh! All of that left thrust increases system gain to the left and critically damps to the right.

2) Power - So, why the power increase? Speed, weight and altitude are constant so lift must be constant. In a left turn the single left side aileron decreases lift on that wing panel. Two things must happen in response: the autopilot must increase angle of attack to maintain lift and it must correct for adverse yaw. That results in a significant drag increase and a compensating increase in power. More power = more system gain resulting in oscillation.

3) Cure - Remove the left thrust - Add a right side aileron - Increase rudder area.

Recall that our best flights were our first few flights with no left thrust (actually, I think there was some right thrust?). As such, I'd say your conclusions are valid. However, I doubt we need more rudder area as it has not showed any lack of effectiveness.

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