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This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Feb 26, 2008, 02:22 AM
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Um...attitude problem...yeeeeeaaaahh


Stepped up the cyclic feedback & got more plots. The dirty secret is attitude hold has always been pretty awful since Corona days & still is. The extra stiffness from software flybar may aggravate the problem.

Next, the RCE-BL35X lost its configuration & went back into throttle mode. 6 hours without a malfunction is pretty good 4 Taiwan. Should program the autopilot to program the ESC.

Attitude hold using straight proportional feedback works for stabilizers like the Copilot & AP2000, but clearly it's not good enough for targeting velocities. Adding integral increases wind resistance to a point, but does not lock it in before it degrades stability. The Gumstix loop isn't fast enough for rate feedback. Its latency is 14ms. The INS latency is 54ms.

That leaves actually going into the PIC & biasing the software flybar to get the desired rotations. Maybe when autopilot is on, cyclic commands become gyro center values & we start over again with gains of 0.001 & plastic blades.

The heading hold algorithm without lowpass filter is bulletproof but now has a definite jitter. Probably need independant bandwidth for yaw & cyclic.
Last edited by Jack Crossfire; Feb 26, 2008 at 02:32 AM.
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