A couple questions regarding a the behaviour of an ideal or theoretical autopilot:
What is the expected or normal behaviour with regards to throttle and elevator trim in altitude control? E.g. if the aircraft is too low, is throttle increase only, used to gain height or is some elevator trim added? What is the convention for full size aircraft?
What does an autopilot do to maintain speed in that situation or what is the relationship between speed and pitch/altitude?
When banking, is up elevator added to maintain height in the turn (bank and yank), or as the aircraft descends in the turn is throttle alone increased to maintain height?
Replies
Hi,
see my post http://diydrones.com/forum/topics/weak-elevator-ese-in-auto-mode
I have some problems with tuning my APM right. When the plane should climb to the next waypoint it increases thrust but doesn't use the elevator (most of the times). Even when it uses the elevator it is too less to climb appropriate.
Now I don't know what to do because I've already tested out all different combinations of PID and other control values..
Hi, about the first one (altitude correction with elevator or with throttle), I think there is free choice. The elevator style is most often used in civilian aviation, and the the throttle style in military.
Yes it is normal to have to correct with some elevator when banking. Ardupilot can add a fraction of the (absolute value) aileron output to elevator by a parameter setting.
Regards
Soren