Re: [Flightgear-devel] AN-225 patch
Hi! Just a little information, if someone wants to animate the nose section (dont look at me, Im still working on the cockpit :-) ) Turning down the ramp takes 7 (!)minutes, the cross-section of the hold is 6.4m, the ceiling is at 4.4m with cranes hanging from it (can lift 20 tons each). I can send you some photos if you want to. Ciao, Adrian - Original Nachricht Von: leee <[EMAIL PROTECTED]> An: FlightGear developers discussions Datum: 26.05.2007 15:22 Betreff: Re: [Flightgear-devel] AN-225 patch > On Friday 25 May 2007 10:36, Joacim Persson wrote: > > On Fri, 25 May 2007, leee wrote: > > > http://www.air-and-space.com/Antonov%20An-225%20Mriya.htm > > > > > > it's the rear four sets. This site also has some nice pics of the main > > > gear, which show that the front three and rear four units are > different, > > > if anyone would like to make more detailed and accurate main gear > units:) > > > > (I can barely make a cube in Blender -- so don't look at me ;) > > > > I suspect it can also kneel like the An-124. Looks like that on some of > the > > pictures too. But the 124 has a different setup with the main gear > > steering, with the two forward axels steerable instead. > > Yeah - it can kneel to lower the nose for loading/unloading but I never > modelled the opening nose or kneeling:) > > > > > And rumor has it they are working on finishing the second 225 down in > Kiev > > now. The one they have in operation is booked up most of the time. > > Yeah (again) - I saw some reports saying that the sole AN-225 is in such > demand that they are going to complete a second airframe, due for completion > > in 2008. > > > > > > The AN-225 also has a max taxiing weight but I couldn't find the doc > > > which stated what it was:( Basically, it means that the AN-225 cannot > > > make ground turns above this weight and so for mtow takeoffs it has to > be > > > lined up on the runway and then loaded. Unlike the AN-124, from which > it > > > was developed, it was never intended for short-field operation. > > > > That information ought to be in the 2001 civil type certificate. (which > may > > have been published in Ukranian only though) I found the type certificate > > number for it: (in latin-faked kyrillic) CTOK200-AH-225, but not the > > document itself. (well, I can't google in non-latin alphabets) > > > > We should add some more hard points to it. One can easily dip a wingtip > or > > engine in the ground now by turning too hard at too high taxi speed. Max > > taxi speed is probably also specified in the type cert. And CG limits, > and > > other goodies... > > The contact points should be ok as the aircraft geometry is fundamental to > YASim and is taken from the 3d model. YASim does recognise ground contact > with wings etc - heh - I've hit the ground with a wing tip in a turn when at > > very low level and realistically spun in and crashed as a result and I've > also clipped a few buildings and structures and got a yaw to the appropriate > > side:) Perhaps the problem is that these collisions don't cause any > damage. > This isn't the fault of YASim because FG only really recognises a total > crash > and doesn't have any provision for partial airframe damage. > > Personally, I wouldn't do anything to pervent the wing tips or outer engines > > grounding when taxiing at too high a speed because I suspect this would be > realistic. It's just the lack of resultant damage that's unrealistic. Of > course, there's certainly scope for further tuning of the undercarriage > springing and displacements - atm it's just tuned so that the a/c sits level > > on the ground at various weights and doesn't collapse on landing, which was > a > serious factor when I was developing it. It was certainly possible to > collapse the nose gear by breaking too hard on the ground at high weights, > which also seemed realistic to me:) I don't think I put any brakes on the > nose gear, just the mains. > > LeeE > > > - > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > ___ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > V
Re: [Flightgear-devel] AN-225 patch
On Friday 25 May 2007 10:36, Joacim Persson wrote: > On Fri, 25 May 2007, leee wrote: > > http://www.air-and-space.com/Antonov%20An-225%20Mriya.htm > > > > it's the rear four sets. This site also has some nice pics of the main > > gear, which show that the front three and rear four units are different, > > if anyone would like to make more detailed and accurate main gear units:) > > (I can barely make a cube in Blender -- so don't look at me ;) > > I suspect it can also kneel like the An-124. Looks like that on some of the > pictures too. But the 124 has a different setup with the main gear > steering, with the two forward axels steerable instead. Yeah - it can kneel to lower the nose for loading/unloading but I never modelled the opening nose or kneeling:) > > And rumor has it they are working on finishing the second 225 down in Kiev > now. The one they have in operation is booked up most of the time. Yeah (again) - I saw some reports saying that the sole AN-225 is in such demand that they are going to complete a second airframe, due for completion in 2008. > > > The AN-225 also has a max taxiing weight but I couldn't find the doc > > which stated what it was:( Basically, it means that the AN-225 cannot > > make ground turns above this weight and so for mtow takeoffs it has to be > > lined up on the runway and then loaded. Unlike the AN-124, from which it > > was developed, it was never intended for short-field operation. > > That information ought to be in the 2001 civil type certificate. (which may > have been published in Ukranian only though) I found the type certificate > number for it: (in latin-faked kyrillic) CTOK200-AH-225, but not the > document itself. (well, I can't google in non-latin alphabets) > > We should add some more hard points to it. One can easily dip a wingtip or > engine in the ground now by turning too hard at too high taxi speed. Max > taxi speed is probably also specified in the type cert. And CG limits, and > other goodies... The contact points should be ok as the aircraft geometry is fundamental to YASim and is taken from the 3d model. YASim does recognise ground contact with wings etc - heh - I've hit the ground with a wing tip in a turn when at very low level and realistically spun in and crashed as a result and I've also clipped a few buildings and structures and got a yaw to the appropriate side:) Perhaps the problem is that these collisions don't cause any damage. This isn't the fault of YASim because FG only really recognises a total crash and doesn't have any provision for partial airframe damage. Personally, I wouldn't do anything to pervent the wing tips or outer engines grounding when taxiing at too high a speed because I suspect this would be realistic. It's just the lack of resultant damage that's unrealistic. Of course, there's certainly scope for further tuning of the undercarriage springing and displacements - atm it's just tuned so that the a/c sits level on the ground at various weights and doesn't collapse on landing, which was a serious factor when I was developing it. It was certainly possible to collapse the nose gear by breaking too hard on the ground at high weights, which also seemed realistic to me:) I don't think I put any brakes on the nose gear, just the mains. LeeE - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] AN-225 patch
On Fri, 25 May 2007, leee wrote: > http://www.air-and-space.com/Antonov%20An-225%20Mriya.htm > > it's the rear four sets. This site also has some nice pics of the main gear, > which show that the front three and rear four units are different, if anyone > would like to make more detailed and accurate main gear units:) (I can barely make a cube in Blender -- so don't look at me ;) I suspect it can also kneel like the An-124. Looks like that on some of the pictures too. But the 124 has a different setup with the main gear steering, with the two forward axels steerable instead. And rumor has it they are working on finishing the second 225 down in Kiev now. The one they have in operation is booked up most of the time. > The AN-225 also has a max taxiing weight but I couldn't find the doc which > stated what it was:( Basically, it means that the AN-225 cannot make ground > turns above this weight and so for mtow takeoffs it has to be lined up on the > runway and then loaded. Unlike the AN-124, from which it was developed, it > was never intended for short-field operation. That information ought to be in the 2001 civil type certificate. (which may have been published in Ukranian only though) I found the type certificate number for it: (in latin-faked kyrillic) CTOK200-AH-225, but not the document itself. (well, I can't google in non-latin alphabets) We should add some more hard points to it. One can easily dip a wingtip or engine in the ground now by turning too hard at too high taxi speed. Max taxi speed is probably also specified in the type cert. And CG limits, and other goodies... - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] AN-225 patch
On Thursday 24 May 2007 19:40, Joacim Persson wrote: > Patch attached. > > Added steering to the four aftmost main gear axels -- with animations! > > Found out just the other day that the AN-225 indeed steers on some of the > main gear wheels. The minimum turning radius is a wild guess however. > (Assumed a 45 deg average on the nose gears.) It now turns (quite > effortlessly) around a point straight out to the side from the second main > gear axel (nr 2 of the 3 non-steerable main gear axels), with a minimum > radius of 25.75 meters. (i.e. near engine nr 1 or 6) The option "squared" > was removed on steering. (Squaring radians messed up my calculations of the > turning angle of the respective wheels. Not that it's a perfect calculation > now either.) Ground wheel steering should, rather, not be connected to > directly the rudder pedals I think... > > Also added transition-time(s) for the steering. Hi Joachim, Yes, the AN-225 does incorporate steering on some of the main units - according to http://www.air-and-space.com/Antonov%20An-225%20Mriya.htm it's the rear four sets. This site also has some nice pics of the main gear, which show that the front three and rear four units are different, if anyone would like to make more detailed and accurate main gear units:) The AN-225 also has a max taxiing weight but I couldn't find the doc which stated what it was:( Basically, it means that the AN-225 cannot make ground turns above this weight and so for mtow takeoffs it has to be lined up on the runway and then loaded. Unlike the AN-124, from which it was developed, it was never intended for short-field operation. One new 'fact' I found while trying to find the max taxi weight was that the takeofff run at mtow is 3500m (11500ft). I think the FG AN-225, at mtow, gets off the ground a little shorter than this - iirc, I tried to tune it so that it could just, and only just, get over the hills after leaving on KSFO 27, figuring that it would be in the right ball park and that it had to work at the default FG airport. LeeE - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] AN-225 patch
Joacim Persson wrote: > README.yasim says the "semi-deprecated" transition-time is "Time in > seconds to slew through input range." I'm not quite sure what it is, > but it's not that. ;) It's coded to assume that the "input range" is 0-1. It was really written for landing gear. If you want to model hydraulic delays (which is what I think is happening here) you'd probably be happier with some Nasal anyway. Thus the "semi-deprecated" note: this feature still works as intended, but there are far more robust ways to solve the same problem in the modern environment. Andy - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
[Flightgear-devel] AN-225 patch
Patch attached. Added steering to the four aftmost main gear axels -- with animations! Found out just the other day that the AN-225 indeed steers on some of the main gear wheels. The minimum turning radius is a wild guess however. (Assumed a 45 deg average on the nose gears.) It now turns (quite effortlessly) around a point straight out to the side from the second main gear axel (nr 2 of the 3 non-steerable main gear axels), with a minimum radius of 25.75 meters. (i.e. near engine nr 1 or 6) The option "squared" was removed on steering. (Squaring radians messed up my calculations of the turning angle of the respective wheels. Not that it's a perfect calculation now either.) Ground wheel steering should, rather, not be connected to directly the rudder pedals I think... Also added transition-time(s) for the steering. By the way: README.yasim says the "semi-deprecated" transition-time is "Time in seconds to slew through input range." I'm not quite sure what it is, but it's not that. ;) (seconds for 2*1.0 on the output property? I.e. for a rotation, that'd be 2.0 radians --? It doesn't operate on the input range taking src/dst translations into account anyway.) Can't tell if this is a code bug or a doc error.Index: data/Aircraft/AN-225/AN-225-yasim.xml === RCS file: /var/cvs/FlightGear-0.9/data/Aircraft/AN-225/AN-225-yasim.xml,v retrieving revision 1.5 diff -p -u -r1.5 AN-225-yasim.xml --- data/Aircraft/AN-225/AN-225-yasim.xml 2 Mar 2006 22:40:56 - 1.5 +++ data/Aircraft/AN-225/AN-225-yasim.xml 24 May 2007 18:01:25 - @@ -164,7 +164,8 @@ them out of my 3d modeller. - + - + @@ -295,43 +319,63 @@ them out of my 3d modeller. + + + + + + + + + + + + Index: data/Aircraft/AN-225/Models/AN-225-model.xml === RCS file: /var/cvs/FlightGear-0.9/data/Aircraft/AN-225/Models/AN-225-model.xml,v retrieving revision 1.3 diff -p -u -r1.3 AN-225-model.xml --- data/Aircraft/AN-225/Models/AN-225-model.xml2 Mar 2006 22:40:57 - 1.3 +++ data/Aircraft/AN-225/Models/AN-225-model.xml24 May 2007 18:01:26 - @@ -1405,7 +1405,7 @@ AN225 model/animation config. L-NG-Strut gear/gear[0]/steering-norm 0 - -45 + -57.30 -20.03 -0.93 @@ -1583,7 +1583,7 @@ AN225 model/animation config. R-NG-Strut gear/gear[1]/steering-norm 0 - -45 + -57.30 -20.03 0.93 @@ -2292,6 +2292,28 @@ AN225 model/animation config. + + + rotate + L-MG-4-IS-Tyre + L-MG-4-OS-Tyre + L-MG-4-IS-Hub + L-MG-4-OS-Hub + L-MG-4-Strut + gear/gear[5]/steering-norm + 0 + -57.30 + + 9.05 + -3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -2472,6 +2494,28 @@ AN225 model/animation config. + + + rotate + L-MG-5-IS-Tyre + L-MG-5-OS-Tyre + L-MG-5-IS-Hub + L-MG-5-OS-Hub + L-MG-5-Strut + gear/gear[6]/steering-norm + 0 + -57.30 + + 10.72 + -3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -2652,6 +2696,28 @@ AN225 model/animation config. + + + rotate + L-MG-6-IS-Tyre + L-MG-6-OS-Tyre + L-MG-6-IS-Hub + L-MG-6-OS-Hub + L-MG-6-Strut + gear/gear[7]/steering-norm + 0 + -57.30 + + 12.42 + -3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -2832,6 +2898,28 @@ AN225 model/animation config. + + + rotate + L-MG-7-IS-Tyre + L-MG-7-OS-Tyre + L-MG-7-IS-Hub + L-MG-7-OS-Hub + L-MG-7-Strut + gear/gear[8]/steering-norm + 0 + -57.30 + + 14.10 + -3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -3552,6 +3640,28 @@ AN225 model/animation config. + + + rotate + R-MG-4-IS-Tyre + R-MG-4-OS-Tyre + R-MG-4-IS-Hub + R-MG-4-OS-Hub + R-MG-4-Strut + gear/gear[12]/steering-norm + 0 + -57.30 + + 9.05 + 3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -3732,6 +3842,28 @@ AN225 model/animation config. + + + rotate + R-MG-5-IS-Tyre + R-MG-5-OS-Tyre + R-MG-5-IS-Hub + R-MG-5-OS-Hub + R-MG-5-Strut + gear/gear[13]/steering-norm + 0 + -57.30 + + 10.72 + 3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -3912,6 +4044,28 @@ AN225 model/animation config. + + + rotate + R-MG-6-IS-Tyre + R-MG-6-OS-Tyre + R-MG-6-IS-Hub + R-MG-6-OS-Hub + R-MG-6-Strut + gear/gear[14]/steering-norm + 0 + -57.30 + + 12.72 + 3.2 + -2.0 + + + 0 + 0 + 1 + + @@ -4092,6 +4246,28 @@ AN225 model/animation config. + + + rotate + R-MG-7-IS-Tyre + R-MG-7-OS-Tyre + R-MG-7-IS-Hub + R-MG-7-OS-Hub + R-MG-7-Strut + gear/gear[15]/steering-norm + 0 + -57.30 + + 14.10 + 3.2 + -2.0 + + + 0 + 0 + 1 + + ---
