Hello,
your observation is interesting, but the Vostok-1 autopilot I think it needs a deep redefinition. My feeling is that they lack basic parameters on the aerodynamics of the R7 rocket and that I'm trying desperately to find in these.
Certainly the problems you have encountered, and that I have also noticed, are due to an accumulation of errors that lead to more correct values that give rise to variables that are no longer compatible with the system. Honestly, I only simulated years ago, guided missiles (V2 for example), and I noticed the importance of the initial values in order to have a good simulation. Theoretically, the orbital flight is simpler than the one that operates in the atmosphere, but is affected by the accumulation of errors. Probably the use of procedures in NASAL, which has a low refresh rate, equal to the frame rate, can lead to problems. I will try, to understand the origin of the instability, to enhance the frame rate, at least at 60 fps (60 Hz) which is half of the 120 Hz of the Jsbsim used.
I suggest you move the discussion in the development forum in order to have a greater number of interested users who can intervene to give advice and maybe to modify a part of the code.
I have a great desire to help put Vostok-1 in place, as it is the prototype of any rocket flying out of the atmosphere. I took a look at the code of the programs that allow the shuttle that seems to have a good ballistic flight, but it is so chaotic, that it seems easier to do everything in a more orderly, perhaps starting from the Jsbsim that is the key to everything and has a rather high calculation speed that should reduce the problem of simulation stability.
Some testI wanted to try Vostok-1 at high frame rates (60 Hz) ... my surprise was great when I saw that the carrier rocket (second stage) did not separate from the third stage! While with 20 Hz framerate this detachment takes place regularly!
But after about 20 minutes of regular operation ... a crash interrupted the flight!
I then repeated the test, I removed the orbital rendering and kept the window larger to have a lower frame rate (about 30-45 Hz) in the first phase of flight. In this test there was the regular detachment between the missile stages. This means that if you start with a very high frame rate (50-60 Hz), something in the NASAL program will not work properly.
The moment of the launch (frame rate 30 Hz):
1-2 minute after, the heart is more far .. the frame rate is 45 Hz
When the second stage is flying alone the frame rate is 60 Hz (maximum frame rate for this FGFS configuration):
Toward the end of the combustion of the second stage (maximum acceleration 3.5 G) a strange fact takes place: The missile begins to change attitude and becomes vertical, but not only
... It becomes negative, as if it were to slow down because of too high orbital speed.
Rocket negative inclination:
Then occurs the detachment of the third stage, also here, according to me, now that the speed is orbital, then the third stage is only a hint to start the engine and then disengages the space capsule.
Detachment of the space capsule from the third stage:
Finally the capsule is free, the frame rate is always 60 Hz even with a rather expanded video .... but ... 30 minutes later ...
- Code: Select all
input is NaN.
input is NaN.
input is NaN.
input is NaN.
input is NaN.
AI error: updating aircraft without traffic record at /media/pc-lab01/Salvataggi/backup/fgfs/flightgear/src/ATC/trafficcontrol.cxx:1663
AI error: Aircraft without traffic record is signing off from approach at /media/pc-lab01/Salvataggi/backup/fgfs/flightgear/src/ATC/trafficcontrol.cxx:1711
Do you report the same problem too? I'm curious