On ven 29 août 2008, Bill Galbraith wrote: > > With Catapult it is less a problem, with answering time > > delay, i mean it should work. > > Catapults features need only to know the "starting position" > > with a more or less value precision: a carrier with 20 km > > speed does 5.6 meter per second => 0.50 1/10 sec => 0.05 1/100 sec > > > > The heading won't be a difficulty, the heading of the > > carrier is not quickly moving. > > I haven't done much with FG or JSBSim lately, but thought I'd add my $0.02 > worth, since I'm working on this stuff on a 'real' simulator. > > Not all carriers shoot off at the carrier's heading. Some US carriers > (sorry, I can't name names) are left of carrier heading, up to 8 degrees. > Some secondary cats (cats 3 and 4) are off even more. (I think they even > show some of that in Top Gun).
Which is right, however, the catapult heading and start position could be given by a Nasal script, if the synchronisation delay is not too high, can we say that something in between 1/10 sec and 1/100 sec remains acceptable ? is realistic ? With the existing CVS JSBSim i have been able to test it, with Foch Zero speed, Dave Culp with his F-4N does it with the Nimitz (the values are within the FDM External_Reactions parameters) > > Plus, the force applied is in carrier axes (with the aforementioned > offset), not in aircraft body axes. The force must be translated into body > axis so that it tracks down the cat track. That way, if you are lined up > poorly on the cat, it straightens you out. > > The carrier is most likely not going to be changing heading or speed during > a launch, but it should be accounted for. With a high-seas condition, the > boat is rock, roll, and heave a lot. Traps are REALLY difficult when the > seas are rough. They probably have to time a shot off a cat to coincide > with an up motion, so that you don't get shot into a wave. YES, the best, would be, to have the right calculation during any high-seas conditions. With a lot of others problems , mainly about the aircraft itself. Will it be, with the existing simulator, able to stay at the right same place when parking? > > Bill > > > Anyhow, we could wonder why that kind of calculation is not out of FDM, that dynamic position calculation, which is necessary to any FDM, is the same. There is no specific good reason (but FG development progress historic ) to find it included into YASim. I should be a module. When collision detection ( which will require a dynamic position calculation) will be done , will it be specific to each FDM ? Regards -- Gérard http://pagesperso-orange.fr/GRTux/ "J'ai décidé d'être heureux parce que c'est bon pour la santé. Voltaire " ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Flightgear-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-devel
