paulrkuntz
New Member
- Joined
- Apr 12, 2011
- Messages
- 21
I have observed what appears to be a bug in the autopilot software. (I'm running the 6.0 version). When the autopilot initiates a turn to a new heading, if the turn is to the left, it tends to roll past the roll limit and keep rolling. I have left it alone up to 70 degrees of roll angle, then intervened when it showed no sign of reversing the roll. this is very repeatable.
My roll limit is set to 20 degrees. When rolling right, it seems to behave as expected. I've tried adjusting roll sensitivity, but the behavior continues.
Last weekend I noticed that I am nearly always getting a roll slip alert when rolling to the left, but not to the right. I don't see a mechanical explanation for this -- the servo and roll torque tube arms are both at 90 degrees to the linking arm at neutral and there is no obvious friction in the system. There may be an aerodynamic difference between left and right roll, and I have noted that the aileron forces are relatively high and cruise speeds, although easily controllable when hand-flying. The roll force is currently set to 100% and it still happens.
So I tried applying some manual left aileron when turning left to assist the roll servo, and when I do that, everything works as expected. The plane rolls smoothly up to the roll limit, maintains that bank angle through the turn, then smoothly rolls level to intercept the new heading and course line.
So, here's what I am calling the software bug:
The roll servo is still applying 100% force to the ailerons, even when it's slipping, but it appears that when the autopilot senses servo slip, it stops monitoring the bank angle when reaching the bank angle limit and continues to apply roll input. At least, that's how it's behaving in my airplane.
Suggestions?
My roll limit is set to 20 degrees. When rolling right, it seems to behave as expected. I've tried adjusting roll sensitivity, but the behavior continues.
Last weekend I noticed that I am nearly always getting a roll slip alert when rolling to the left, but not to the right. I don't see a mechanical explanation for this -- the servo and roll torque tube arms are both at 90 degrees to the linking arm at neutral and there is no obvious friction in the system. There may be an aerodynamic difference between left and right roll, and I have noted that the aileron forces are relatively high and cruise speeds, although easily controllable when hand-flying. The roll force is currently set to 100% and it still happens.
So I tried applying some manual left aileron when turning left to assist the roll servo, and when I do that, everything works as expected. The plane rolls smoothly up to the roll limit, maintains that bank angle through the turn, then smoothly rolls level to intercept the new heading and course line.
So, here's what I am calling the software bug:
The roll servo is still applying 100% force to the ailerons, even when it's slipping, but it appears that when the autopilot senses servo slip, it stops monitoring the bank angle when reaching the bank angle limit and continues to apply roll input. At least, that's how it's behaving in my airplane.
Suggestions?