OHM Orion autopilot

[OrbitHangar]

Author: pclaurent

Add-on Description:

This add-on for Orbiter 2016 is designed as a companion MFD for francisdrake’s Orion-MPCV spacecraft and its default “Orange SLS” launcher (https://www.orbiter-forum.com/showthread.php?t=34839).

It currently it contains 3 functions:

• SLS launch autopilot: launches the SLS and puts Orion + EUS (Exploration upper stage) in a low earth circular orbit.
• Reentry autopilot: manages Orion-MPCV earth reentry from LEO to a defined splashdown point.
• “Return home” feature: calculates a splashdown point when returning from a moon mission.

Installation

• Unzip the installation file in the Orbiter root directory (e.g. C:\Orbiter2016).
• Go to <root directory>\Config\MFD, open file ScriptMFD.cfg and add a line containing “MFD\OrionAP.cfg”
• Put a semi-colon at the beginning of unneeded script MFD lines if you like. For example:

MFD\OrionAP.cfg
;MFD\Attitude.cfg
;MFD\TestMFD1.cfg
;MFD\TestMFD2.cfg

• In the Modules tab of Orbiter launcher, check the “ScriptMFD” checkbox.

2018-04-12 update:

- Improved landing point accuracy in RET mode.

- Various display improvements.



DOWNLOAD

 

[Gtazsk]

What Azimuth and inclination should I use for make a circular orbit ? I tried with shuttle launching data but every time I didnt make a good orbit

 

[pclaurent]

CPU usage

Remark from the author: the ascent autopilot (SLS mode) takes control every 0.1 second for making trajectory adjustments. If you are using XR Sound it is recommended to increase the UpdateInterval value to 0.1 in the XRSound.cfg file.

 

[francisdrake]

I have changed the XRsound update intervall to 0.2 sec without any hickups. My feeling was XRsound is competing with other ressources, e.g. the inital loading of the base textures took longer than with the default Orbiter installation.

# The default value is 0.05 (20 updates per second).
#--------------------------------------------------------------------------
UpdateInterval=0.2

 

[dbeachy1]

I've run benchmarks and not seen any framerate impact at all from XRSound, even at 50 updates per second (interval 0.02; the default is 0.05, or 20 updates per second). Can you please run some controlled tests both with XRSound loaded and without? If you're seeing a performance impact, please post the scenario and steps to reproduce it and I'll see if I can duplicate it.

EDIT:
Specifically, here are the benchmark numbers from a few days ago when I ran performance tests w/the default "DG Mk4 in orbit" scenario in external view with the default DX7 client, 1920x1200 window mode, with UpdateInterval = 0.02, which is 50 updates per second (2.5x the default of 20 updates per second):

   With XRSound loaded: 260 fps
Without XRSound loaded: 260 fps

I had the same results with the default update interval of 0.05 (20 updates per second) as well. Testing with the D3D9 client showed the same result -- no detectable performance impact:

D3D9 client w/the default "DG Mk4 in orbit" scenario in default cockpit view:

   With XRSound loaded: ~1550 fps
Without XRSound loaded: ~1550 fps

Actual FPS varied each second between 1500 and 1600, but 1550 was the average.

XRSound doesn't do any CPU-intensive work in its code (XR vessels, which update their 2D panels at 20 times per second by default, do literally 50x the work each update) so if you really are seeing a performance impact just from running XRSound, I'd like to know how to reproduce it so I can investigate.

 

[Face]

XRSound doesn't do any CPU-intensive work in its code (XR vessels, which update their 2D panels at 20 times per second by default, do literally 50x the work each update) so if you really are seeing a performance impact just from running XRSound, I'd like to know how to reproduce it so I can investigate.

The addon here is an interpreted(!) algorithm that involves matrix operations in every time-step. Perhaps some rate limitation feature like e.g. this Lua if-clause at line 528 of OrionAP.cfg's prestep function is not working properly?

if oapi.get_simtime() - t0 > MET + 0.1 then  -- APs are invoked each 1/10 sec.

 

[francisdrake]

It seems I have loading stutters. When new audio is loaded, the framerate drops to zero for a few moments. If this happens, e.g. at stage seperation (callout), it skips a few frames, which throws the Autopilot off course.

This might not specifically be an XRsound topic, but a general ressource topic, or how interrupts are handled on my PC.

 

[pclaurent]

OrionAP actually is a script-MFD, and as so uses an LUA script. The autopilot takes hand each 0.1 sec (which appears to be a good compromise between guidance accuracy and CPU usage, at least on the configuration I used for tests). It seems that with some add-ons it can cause some frame hang-on. Changing the refresh rate in either add-on seems to be the best option. If it’s not in XRSound, it can potentially be in OrionAP, by changing the rate from 0.1 to 0.2 for instance. Didn’t try it, as I’ve switched my priorities, but feel free to change the OrionAP.cfg script. If it works, I’ll consider an OrionAP update.

 

[daubm]

Not sure why but the autopilot is putting me into a highly elliptical orbit. If anyone knows how to adjust the config file to fix this it would be greatly appreciated

 

[GodAtum]

Thanks for this addon. I am trying the Orange-SLS Lunar Mission scenario but when I launch it crashes into the ground.

SLS Active Step 3 Pitch program 70 deg in 12 sec

 

[ggrof]

When I launch the lunar mission scenario i get a CTD. There is because i have not the Lunar Module MAV and I can´t find it in orbithangar. Someone knows where could I find it?

 

[turtle91]

>.... i have not the Lunar Module MAV and I can´t find it in orbithangar
https://www.orbiter-forum.com/showthread.php?t=36504

 

[Sbb1413]

Re: OHM Orion autopilot

Francisdrake does not always host his add-ons in Orbit Hangar.

 

[francisdrake]

Yes, sorry for the inconveience. Pls search the forum for the MAV thread. It is in Addon Development. The current MAV version can be downloaded from the first page of this thread.