problem on pitch axis

[gianmarko]

2xD10a, AP74, pitch and roll
today i tested the AP with the latest firmware. everything works ok except that when i change the altitude using the AP74, nothing happens and the a/c keeps flying at the same alt.
tried disengaging and reengaging alt but no result
wx was deteriorating so couldn try again after cycling power. i havent changed any parameter after sw upgrade
anybody had this problem?

 

[DBRV10]

This is for an RV10 with SV52's so the torque values you will find different but this might give you a clue. I think your gains are too low.

Also follow the instructions and tune as you need.

Here are the pitch and roll servo settings.

 

[gianmarko]

here my values. havent change any parameter since software upg

still dont think some wrong setting shoudl freeze altitude changes

 

[dynonsupport]

2xD10a, AP74, pitch and roll
today i tested the AP with the latest firmware. everything works ok except that when i change the altitude using the AP74, nothing happens and the a/c keeps flying at the same alt.
tried disengaging and reengaging alt but no result
wx was deteriorating so couldn try again after cycling power. i havent changed any parameter after sw upgrade
anybody had this problem?

Hi,

Are you changing the altitude bug after engagement and the AP is not following it?

Does the bug move when the AP is engaged on the ground?

Does ALT mode work correctly when the AP is controlled from the D-10A buttons, instead of the AP-74?

Thanks,
Dynon Support

 

[gianmarko]

Hi,

Are you changing the altitude bug after engagement and the AP is not following it?

- yes, AP doesnt follow

Does the bug move when the AP is engaged on the ground?

- havent checked that

Does ALT mode work correctly when the AP is controlled from the D-10A buttons, instead of the AP-74?

- havent checked this either. the popup appears pushing the AP74 button and altitude value changes too, also changes the value on the efis screen, low right. but AP doesnt follow. tried changing for higher or lower alt, but AP just keeps flying straight and level.

 

[dynonsupport]

Do you get any indication of servo slippage (status line for pitch axis backgrounded in yellow instead of the normal black)

 

[gianmarko]

no, pitch control forces are very light, there is never any slippage

airplane just hangs stubbornly there, if i dial in a lower alt, and reduce power, the AP starts flying nose up

Do you get any indication of servo slippage (status line for pitch axis backgrounded in yellow instead of the normal black)

 

[dynonsupport]

What kind of airplane is this? What are the speeds that you're typically flying when under AP control?

 

[DBRV10]

Try winding up the Pitch ALT and VSI gains. Have a look at the numbers I posted.

This aircraft must be fairly slow if its MAX Airspeed is 0nly 102 knots.

 

[gianmarko]

is a LSA-like airplane, my typical cruise speed is around 90kts

What kind of airplane is this? What are the speeds that you're typically flying when under AP control?

 

[gianmarko]

ok will try that


but bear in mind, before upgrading to 5.4 AP was working perfectly fine, and i havent changed any parameter at all after upgrade

might be a glitch, will try again the AP next weekend if weather collaborates.

Try winding up the Pitch ALT and VSI gains. Have a look at the numbers I posted.

This aircraft must be fairly slow if its MAX Airspeed is 0nly 102 knots.

 

[gianmarko]

yesterday more testing.

i tried engaging the AP and setting a different altitude. still no joy. flying at 2500, set 2000, no change of alt

i tried setting 3000, and the airplane starts climbing.

i increase alt gain to 10 and vsi gain to 18, still AP goes up, but not down

then i increase VSPD to 500ft/min and now AP works fine.

however 500ft is a bit too much for my airplane. is a very light plane, when flying in turbulence even small thermics will kick me up 500ft in no time, then AP pitches down to regain the set altitude, at 500ft/min speed will shoot up and will require continuous throttle changes.

 

[DBRV10]

leave it set to 500ft/ min. I now have 700.

In turbulence you should pull the power back and disconnect the ALT function and hand fly the vertical. Leave the HDG / TRK / NAV engaged if you want.

 

[gianmarko]

eh my friend

on an a/c with empty weight of 300kg, there is always turbulence

i think the AP should work even set at 200ft/min. it did before sw update

leave it set to 500ft/ min. I now have 700.

In turbulence you should pull the power back and disconnect the ALT function and hand fly the vertical. Leave the HDG / TRK / NAV engaged if you want.

 

[dynonsupport]

Hi,

I would suggest reducing the vsi_gain.  

Note that the AP will not hold a vertical speed the airspeed reaches the limits set in the AP menu.  So if you try to descend at 500fpm and your AIRSPEED_MAX of 195 kph is exceeded, the AP will hold 195kph and descend at whatever vertical speed results at that power setting.  The AP will let you know by displaying "REDUCE POWER".

yesterday more testing.

i tried engaging the AP and setting a different altitude. still no joy. flying at 2500, set 2000, no change of alt

i tried setting 3000, and the airplane starts climbing.

i increase alt gain to 10 and vsi gain to 18, still AP goes up, but not down

then i increase  VSPD to 500ft/min and now AP works fine.

however 500ft is a bit too much for my airplane. is a very light plane, when flying in turbulence even small thermics will kick me up 500ft in no time, then AP pitches down to regain the set altitude, at 500ft/min speed will shoot up and will require continuous throttle changes.

 

[gianmarko]

hi
yes i am aware of that.

i will reduce VSI gain to the previous value

Hi,

I would suggest reducing the vsi_gain.  

Note that the AP will not hold a vertical speed the airspeed reaches the limits set in the AP menu.  So if you try to descend at 500fpm and your AIRSPEED_MAX of 195 kph is exceeded, the AP will hold 195kph and descend at whatever vertical speed results at that power setting.  The AP will let you know by displaying "REDUCE POWER".

yesterday more testing.

i tried engaging the AP and setting a different altitude. still no joy. flying at 2500, set 2000, no change of alt

i tried setting 3000, and the airplane starts climbing.

i increase alt gain to 10 and vsi gain to 18, still AP goes up, but not down

then i increase  VSPD to 500ft/min and now AP works fine.

however 500ft is a bit too much for my airplane. is a very light plane, when flying in turbulence even small thermics will kick me up 500ft in no time, then AP pitches down to regain the set altitude, at 500ft/min speed will shoot up and will require continuous throttle changes.