Problem AMSO 1.19 launches not acheiving orbital insertion.

[skyteller59]

Everything seems to work fine for 100606, but when I launch from a clean install with 100830 and orbiter sound 3.5 the vehicle doesn't correct for orbital insertion and burns up on reentering atmosphere.

 

[ACSoft]

Hello,

You should probably do something wrong. I just ran scenario "AS-506\Apollo 11 step 01.scn" with Orbiter 2010-P1 and got a perfect orbit.

Check you don't have unlimited fuel set. Check you don't loose the autopilot during the ascent (the white "AP" label dissapear). This may happen with a joystick badly calibrated, or if you apply a manual fly command on the keyborad.

ACS

 

[skyteller59]

Hello,

You should probably do something wrong. I just ran scenario "AS-506\Apollo 11 step 01.scn" with Orbiter 2010-P1 and got a perfect orbit.

Check you don't have unlimited fuel set. Check you don't loose the autopilot during the ascent (the white "AP" label dissapear). This may happen with a joystick badly calibrated, or if you apply a manual fly command on the keyborad.

ACS

Thank you for the advice. I tried everything that you suggested, still no joy. The joystick seems to be well adjusted. However I discovered that the sim loses the AP after about 6 min. into the flight (+- some), something I hadn't noticed before. I also have the camshake mod, but I deactivated that per instructions, and again no luck. Still thanks for the advice.

 

[ACSoft]

Yes I am almost sure the camshake module has nothing to do with this problem, but it is right to not use it with AMSO just because camera shaking function is integrated into AMSO.

Nevertheless, do the following test:

Deactivate all your modules, except OrbiterSound and try again to see if it make a difference. If not, let the modules deactivated and deactivate the following parameters:
"damage and failure simulation", plus all the "Perturbation" parameters and try again, of course, only if your parameters settings were different.

While flying the ascent during one of your tests, please press "F" an tell me what frame rate you get (be sure to have video option "disable vertical sync" activated).

Let's hope these tests will reveal why you are loosing autopilot control.

As I said, giving any manual "driving commands", will immediately mean for the autopilot, you want to take manual control and it is why it disconnect. But it can also disconnect if it does not succeed to maintain the rocket in some tolerances around the desired trajectory path. It is probably what happen in your case and I need to discover why !!!

ACS

 

[skyteller59]

Hello ACSoft,

I tried out your suggestions, and it appears that the problem lies with the "nonspherical gravity source" and the "gravity-gradient torque" parameters. When I turn these off, the AMSO launches succeed. However, this seems only to work after I exit, and then restart the Orbier LaunchPad in its default (de-allocate memory) setting. In addition, the AP was cutting out consistently at 6 min. 25 sec. into the flight, with a framerate of approx. 68 FPS on my system. I hope this helps you with your evaluation, and thank you.
"I'm breathing again".

Skyteller59, out.

 

[JonnyBGoode]

With having nonspherical gravity source on, I've only had problems once... that was when the autopilot malfunctioned. Check to see whether or not you have damage and failure simulation turned on?

 

[Jarvitä]

I can confirm the problem. Using the AS-506 step 1 scenario and launching with autopilot, the autopilot always shuts off around GET 7 minutes.

 

[JonnyBGoode]

Confirm, Apollo 11 AP cutoff at 6 minutes 23 seconds.

 

[skyteller59]

Confirm, Apollo 11 AP cutoff at 6 minutes 23 seconds.

The only difference that I've noticed with "damage & failure" on, is a warning alarm when the AP cuts out. Have you tried turning "nonspherical gravity source" & "gravity-gradient torque" parameters off. This works for me dudes.

 

[JonnyBGoode]

I turned off "nonspherical gravity source" (I didn't have "gravity-gradient torque" on) and still got the cut-off at 6 plus 23. And the craft was veering wildly off course just prior to that and started into a flat spin.

 

[ACSoft]

Hello,

This is what I wrote in the AMSO manual:

Non-spherical gravity sources: AMSO is not sensitive to this feature. So the setting of this option is irrelevant.

Gravity-gradient torque: Earth orbit injection autopilot trajectory precision is affected if this option is on. So it is better to turn it off. Note that if you set it on, the autopilot will still be able to build orbit but not in the most optimum way.

This is why, I am already surprised that, for some of you, apparently now "gravity-gradient torque" MUST be turned off, otherwise the autopilot cannot compensate or even for "JonnyBGoode" autopilot seem to always fail, like he explain here:

I turned off "nonspherical gravity source" (I didn't have "gravity-gradient torque" on) and still got the cut-off at 6 plus 23. And the craft was veering wildly off course just prior to that and started into a flat spin.

Since the days I made some tunings in the autopilot for these problems and then, wrote the settings advices in the user manual, I mentionned before, I wonder how much the frame rate may have an influence on that.

Normally, with "Gravity-gradient torque" on, the autopilot might fail sometimes, but this should be rare. A systematic failure or even the "JonnyBGoode case" seem abnormal to me. It really seem that something changed around this.

"JonnyBGoode", you confirm ? Did the autopilot ALWAYS fail for you, even with "Gravity-gradient torque" OFF ? What frame rate do-you have ?

I will try again to do some tunings in the autopilot code and let you try a the new module, so you call all test if it goes better.

ACS

 

[skyteller59]

Hello ACSoft,

As is the case with "JonnyBGoode", my ship also veers wildly off-course in a flat spin, just as he describes. In addition, I need to uncheck both the "nonspherical gravity source" and "gravity gradient torque" parameters, for most of the launches to succeed. However, since I had just installed an Apollo 15 sound pack, I decided to launch that mission with all gravity parameters turned on, and the spacecraft reached its' intended orbit. Hope this is of some help.

 

[ACSoft]

Hi Guys !

I have revisited the code of this Earth orbit injection autopilot.

The first test I made revealed that even on my PC, it was relatively critical. So, I have "re-centered" tolerance margins and added some improvement to the critical part, which happen around 7 minutes and 15 seconds.

At that time, the autopilot activate a new part of the code and if the flying parameters of the rocket, at that time, are outside some tolerance margins, the code execute too wild corrections and cannot anymore stabilize the rocket. This is what "JonnyBgood" had, when he said "the craft was veering wildly off course".

Please download here a test package:
http://www.acsoft.ch/tmp/EOI-test.zip

It contain a new "Apollo.dll" module for you all guys to test. The module goes naturally into "Orbiter\Modules\AMSO" directory.

I have also included an Apollo 11 launch scenario, to facilitate your tests. This scenario is a save about just 30 seconds before launch time. So you don't need to wait long. You just have to press on "K" key precisely at 13:31:50.

Notice that respecting the launch time IS IMPORTANT for scenario using the lateral autopilot, to capture the LOI plane. This is BECAUSE SOME PARAMETERS OF THIS FUNCTION, RELY ON SOME MOON ORBIT CHARACTERISTICS AT THAT TIME. This is what say the user manual on that matter:

MJDLOI: MJD time of the LOI (Lunar Orbit Moon). If this parameter is specified the AMSO Saturn V autopilot, it will steer the yaw axis in order to intercept the Moon plane at the time of LOI during the ascent to Earth parking orbit. The result is an Earth parking orbit very precise for the subsequent TLI burn. IMFD5 uses this parameter to preset the arrival time of the program “Intercept Target”.

Do not activate Orbiter "Damage and failure simulation". Because if you have an AUTOPILOT MALFUNCTION, you won't know if it was a fake one, randomly generated, or if it correspond to a real disconnection because of our problem. With this Orbiter parameter OFF, in case the autopilot disconnect, it will mean you still have the problem.

With the improvements I have added, normally, it should work more or less the same WITH OR WITHOUT ANY OF THE ORBITER PERTURBATIONS PARAMETERS ACTIVATED. Please, check it is also the case on your PC.

For now, I have only checked Apollo 11. But I must still test all the other launch scenarios, because of rather different lateral autopilot guidance and also different launch azimut. Please, do not hesitate to do the same !!! In any cases, I will wait your feedbacks (numerous I hope !), before to publish this correction.

Thanks in forward for your collaboration.

ACS

 

[skyteller59]

Hello ACSoft,

Although I didn't check all the launch scenarios, the ones I did try (sorry I didn't note which ones) all seemed to function properly, including a fraction of the non-launch scenarios. As far as I can detemine, your EOI test module has corrected the problem for orbital injection, with or without the gravity parameters set. I apologize for not taking better notes, I'll try to be more informative next time. Thank you for an outstanding addon, one of the very best for Orbiter.

 

[JonnyBGoode]

Sorry, I've been away a bit and haven't kept up on this thread. I'll have a look at the suggestions and the new beta patch as soon as I can, and get right back to you all. :tiphat:

---------- Post added at 02:31 PM ---------- Previous post was at 12:14 PM ----------

Haven't tried the new DLL with any of the other scenarios yet, but with the test scenario given it passed the 6 plus 23 threshold and achieved a perfect orbit. :thumbup: