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From: | Edixon Giraldo |
Subject: | RE: [Paparazzi-devel] Reply to "How to adjust surface travel and throttle? (Edixon Giraldo)" |
Date: | Tue, 17 Aug 2010 10:00:30 -0500 |
This is a great explanation Chris. Thank you very much. Let me just clarify, I take off in MANUAL and switch to AUTO1 high enough. Do I launch the A/C in the GCS, or, am I just switching to AUTO1 and controling with the radio to check the roll and pitch angles? I already see from the commands in the aircraft.xml that I don't have the same section for the AUTO1 as you mentioned. I need to correct that. Maybe that would make things better. The section: <define name="HORIZ_SENSOR_TILTED" value="1"/> <define name="LATERAL_CORRECTION" value="1.0"/> <define name="LONGITUDINAL_CORRECTION" value="1.0"/> <define name="VERTICAL_CORRECTION" value="1.5"/> calibrates the PFD to actual angles, correct? I am just making sure that is what I understood. How about the throttle part? How do I match the throttle of Auto2 to that of manual and Auto1 to maintain cruise speed? Thanks. Eddie. > Date: Tue, 17 Aug 2010 17:35:37 +0300 > From: address@hidden > To: address@hidden > Subject: [Paparazzi-devel] Reply to "How to adjust surface travel and throttle? (Edixon Giraldo)" > > I always hand launch in auto2 without a single failure until now. > What i simply do is in the early stages of tuning to fly manual first > and engage AUTO1 high > enough in order to see if the plane turns as expected. > In the airframe file there is a section that defines the maximum bank > angles in AUTO1 > <section name="AUTO1" prefix="AUTO1_"> > <define name="MAX_ROLL" value="RadOfDeg(45)"/> > <define name="MAX_PITCH" value="RadOfDeg(45)"/> > </section> > and i always make sure that i can achieve those during AUTO1 flight. > > If i can't then the PFD is not showing the actual pitch and roll angles > because the > <define name="HORIZ_SENSOR_TILTED" value="1"/> > <define name="LATERAL_CORRECTION" value="1.0"/> > <define name="LONGITUDINAL_CORRECTION" value="1.0"/> > <define name="VERTICAL_CORRECTION" value="1.5"/> > need to be adjusted. > > You can also adjust each side alone using those definitions: > <define name="CORRECTION_UP" value="1."/> > <define name="CORRECTION_DOWN" value="1."/> > <define name="CORRECTION_LEFT" value="1."/> > <define name="CORRECTION_RIGHT" value="1."/> > > Then after i achieve correct roll and pitch indications i increase the > roll and pitch gains until > the oscillations just begin. > Finally i decrease the gain 500 units from where the oscilations begin. > For example if the oscillations start at a gain of -7500 then i set the > gain at -7000. > Those gains mainly affect the servo movement when you roll and/or pitch > the aircraft > as the calculate the servo movement from the angle error. > For example if the wind has forced the plane to roll -10 degrees (to the > left, positive is to the right) > then the autopilot will calculate that it needs to change the aileron > servo pulse width from 1500 to 1600 with a gain of -5000 and to 1700 if > the gain is set to -10000!!! > I hope i made that clear. > This of course will only work if the -10 degrees the autopilot sees are > indeed -10 degrees and not -20 > because your PFD indications are in error. > To make things worst if you use slow servos you will find that the > minimum needed gain induces oscillation where if you have used fast > servos (0.1ms or lower) you could increase the gain even more. > A slow servo will take more time to get to the desired angle and until > it reaches it's position > the autopilot sees that the plane is not responding well and commands > more servo travel. > When the servo finally reaches the commanded angle the plane has started > to roll to the opposite side > due to over correction and the autopilot commands an opposite servo > movement only to overshoot again and the oscillation start. > Chris > > > _______________________________________________ > Paparazzi-devel mailing list > address@hidden > http://lists.nongnu.org/mailman/listinfo/paparazzi-devel |
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