AeroBrakeMFD Can't change reference AoA?

[rocketman768]

After setting the reference AoA, you used to be able to change it with Shift+Num8 or Shift+Num2. Now that I have upgraded to orbiter 2010 and Aerobrake 0.96.1, it seems I can no longer do this. Is this a glitch, or am I the only one?

 

[jambooger]

What ship are you flying?

 

[rocketman768]

What ship are you flying?

The XR2. Also, I'm in Windows 7 64-bit.

 

[jambooger]

The XR2. Also, I'm in Windows 7.

Ah, I fly the same ship. What version Orbiter? Dougs new XR's only work with 2010 P1.

Im not having the problem you are. Num8 nose down, Num2 nose up, Num4 bank left, Num6 bank right. I hope I stated that correct but works fine for me.

Just re-read your post. "Shft" not necc.

 

[rocketman768]

Ah, I fly the same ship. What version Orbiter? Dougs new XR's only work with 2010 P1.

Im not having the problem you are. Num8 nose down, Num2 nose up, Num4 bank left, Num6 bank right. I hope I stated that correct but works fine for me.

Just re-read your post. "Shft" not necc.

This is Orbiter 100830. Shift or no shift, the AoA reference change isn't working. Just to be clear, I am talking about the AoA/bank control loop for Aerobrake, not the one on the XR2 itself.

The Aerobrake version number is 0.96.1.

 

[jambooger]

This is Orbiter 100830. Shift or no shift, the AoA reference change isn't working. Just to be clear, I am talking about the AoA/bank control loop for Aerobrake, not the one on the XR2 itself.

The Aerobrake version number is 0.96.1.

oops, I did misunderstand your question. Not familiar with your problem, sorry. maybe someone else can help out.

 

[Alexw95]

Why not just use the Xr2 autopilot for AoA/Bank hold?

 

[Wishbone]

Which Shift are you pressing, the left or the right one? And on what screen does the Aerobrake MFD reside? (hint - press left shift for left screen, right shift for right screen).

EDIT: missed the XR2 part, she may be intercepting your keystrokes if her own autopilot is on.

 

[rocketman768]

Why not just use the Xr2 autopilot for AoA/Bank hold?

The XR2's autopilot cannot do an inverted re-entry due to the bank angle limitation (+- 60 degrees?).

Which Shift are you pressing, the left or the right one? And on what screen does the Aerobrake MFD reside? (hint - press left shift for left screen, right shift for right screen).

EDIT: missed the XR2 part, she may be intercepting your keystrokes if her own autopilot is on.

Right or left shift gives the same result. The XR2's autopilot is not on, but maybe still somehow is intercepting keystrokes? I guess I would need to try it in the DeltaGlider or something to see if it is the vessel.

 

[Tommy]

I doubt you'll have much luck using AerobrakeMFD's Attitude hold for an inverted re-entry - you'll likely get a lot a lot of "wobble" that get's progressively worse as dynamic pressure increases.

If you give the COG shift a couple quick taps to move the COG towards the rear, elevator trim can be used to maintain AoA while inverted. An example can be found in the Home Direct tutorial found at OH (this tutorial is also included in the IMFD Full Manual/Playbacks tutorial, also at OH. While the tutorial uses IMFD for a Moon-Earth transfer, you can still use the flight recording without having IMFD installed.

 

[rocketman768]

Definitely NOT just the XR2. I can't change the reference AoA within the stock DeltaGlider either.

I doubt you'll have much luck using AerobrakeMFD's Attitude hold for an inverted re-entry - you'll likely get a lot a lot of "wobble" that get's progressively worse as dynamic pressure increases.

If you give the COG shift a couple quick taps to move the COG towards the rear, elevator trim can be used to maintain AoA while inverted. An example can be found in the Home Direct tutorial found at OH (this tutorial is also included in the IMFD Full Manual/Playbacks tutorial, also at OH. While the tutorial uses IMFD for a Moon-Earth transfer, you can still use the flight recording without having IMFD installed.

Thanks for the tip about the COG.

However, I can obtain satisfactory results with the AoA control loop. If you didn't know, the controller is a PID controller whose parameters you can specify in a config file somewhere. Since I have taken courses in feedback control, it's not hard for me to figure out the right parameters.

For anyone who's interested in the PID tuning, the plant transfer function is of the form G(s) = A/s^2, and you really only need PD control D(s) = K(T_d*s+1). So, K_p = K, and K_d = K*T_d. Obviously, you are placing a zero at -1/T_d which pulls the two poles at 0 back into stability. However, be aware that the farther the zero is placed in the left-half plane, the larger the gain K you will need for stability, which is bad for two reasons: 1) disturbance inputs and 2) Uses more fuel.

 

[Tommy]

It would be nice if you posted your tuned version of that config file - many people have the problem with oscillation. I wonder if the parameters might vary depending on the framerate achieved by the user's computer - since that would affect the timing of the loop? I'm not nearly familiar enough with PIDs to know if that could be an issue or not.

 

[rocketman768]

It would be nice if you posted your tuned version of that config file - many people have the problem with oscillation. I wonder if the parameters might vary depending on the framerate achieved by the user's computer - since that would affect the timing of the loop? I'm not nearly familiar enough with PIDs to know if that could be an issue or not.

Modules/Plugin/XR2Ravenstar.ld

ALT P -0.500000
ALT I -0.009000
ALT D -3.60000
BANK P -100.00000
BANK I -1.00000
BANK D -100.00000
AOA RCS P -100.00000
AOA RCS I -1.000000
AOA RCS D -100.0000
AOA ELEV P -100.000000
AOA ELEV I -70.000000
AOA ELEV D -80.000000

Now, is no-one else who's using Windows 7 64-bit and aerobrake have this problem with the non-changeable reference values?

---------- Post added 11-24-10 at 10:52 AM ---------- Previous post was 11-23-10 at 10:11 PM ----------

Aha! Seems I need to turn off the Num-lock. Fixed.