I am interested in the basics of what each of the 12 PID paramaters actualy controls and the relation of one to another.....
I have read and really have a pretty good grip on PID's, the adjustments and gain factors.
Servo - roll, pitch, yaw. Correct me if I'm wrong...PID tuning all coresponds to how the servo responds to where the NAV portion says that it should be. ie NAV calls for a 45 deg RH bank roll PID is the control of how quickly/precisely a roll is exicuted.
NAV - all has to do with the navigation of the airplane and how navigational changes are made to guide the airplane to its next waypoint.
That being said here is where my questions come in....Nav Roll - simple enough. Nav Pitch AS, NAV Pitch Alt - obviously one is airspeed while the other is altitude.
1. How does one corespond with the other?
2. Why is it that when I watch my flight log after flying a mission NAV Pitch stays above 0 at all times, the Servo Pitch follows NAV Pitch and my plane continues to climb through the entire mission as well.
3. Energy/Alt PID - information needed.
4. Other Mix's - P to T...I am guessing Pitch to Throttle?
Pitch Comp - information needed.
Rudder Mix - Rudder to Aileron Mix.
5. Throttle 0-100%
Cruise - % of throttle while at Cruise
Min/Max - self explanatory
FS Value - Fail Safe Value
6. Xtrack Pids - information needed.
Gain (cm) - is this similar to a "Target Point Distance"?
Entry Angle - information needed.
7. Navigation Angles *100 - seems odd to me that for a 45 deg bank you have to put in 4500 (just a thought, maybe there are bigger reasons to this).
Bank Max, Pitch Max, Pitch Min - all self explanatory.
8. Airspeed m/s
Cruise * 100 - again, I don't get why it is multiplied by 100???
FBW Min, FBW Max - self explanitory.
Ratio - ratio of what to what????
I've looked and haven't found a thread anywhere that talks about all of this, if there is a link could someone please send it to me?
"I don't get why it is multiplied by 100"
A lot of the maths in APM use scaled integers to avoid floating point. The config tools are exposing you to that fact, maybe unnecessarily, but that's easier for the developers right now. I'm sure it will evolve over time. Just assume all angles and speeds are * 100, and lat/long is 10x7.
I have a post on Crosstrack PIDS, with an interactive tool on setting them.
AS ratio is tuning thing. More to do with getting the most accuracy out of your Pitot setup.
Thanks for help with the deffinitions, this will help a lot. 5 was not a question, just going through each of the setup values.
This was my first attempt at flying a mission. Flies great is Stabilize Mode. In FBW_B full throw left and right on the ailerons only gives me about a 5 to 10 deg roll, I should have 45 deg. If I am understanding correct I need to up the P on the Roll Servo. I did log the flight, I will add the file if you wouldn't mind taking a look at it.
Maybe this is what you are looking for?
I've successfully got my aircraft flying in auto and navigating waypoints. (Radian powered glider & APM 2.3) However, I too could use some more background on tuning.
With the parameters mentioned above, can you provide some examples of which way one would drive the various parameters (from default) if tuning a high wing aspect airframe like a glider, versus a low aspect airframe such as a fighter.
I'm also very curious about the pitch to throttle as well, and what types of airframes it would be used for.
In my case, I noticed the pitch comp was excessive (climbed in a turn) so I reduced it.