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Author
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Topic: how to make ailerons REALLY detach
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charmstar
Pilot
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posted 02-23- 12:20 AM
   
OK, this is what seems to work for me. I'll use the SE5a as an example (and because that's what I tested my theory on). This has 4 ailerons (UL, LL, UR, LR).
First, I looked at the text for each wing that was associated with each aileron. I copied all of the airfoil properties, including things like airWing, airRuntime, and the airfoil info.
Then, I pasted all of this into the aileron that was attached to the wing.
Then, I made the airArea for the ailerons like 6 feet, and changed the chord to be 1 foot. I also changed the airfoil to NACA0010 I believe... it was the one being used for the horiz stab)So, here is the ULAileron new props:
(airRuntime .2) (obProto 'CAirfoil) (airWing) (airSection "NACA0010") (airK 0.6) (airAR 5.5) (airAdvantage .4) (airMax .5) (airArea 6) (obAirfoil (airChord 1 airPT 0.352299, 0.424430, -0.180824 airControl airObject 'ULAileron))
Then, I went back to the wing, and deleted the airRuntime, and in the airfoil info deleted the reference to the aileron (ULAileron for instance), as well as the airControl. I did leave the airchord info, and the airpt info there however. ALso, I subtracted 5 feet from the wing area, to make up for the 5 i added to the aileron.
Next I clicked the ailerons again, and modified the airpt to be 1/4 back and in the middle of each aileron model.
Finally, I clicked on the fuselage model, and added 'ULAileron and 'LLAileron to the leftwing list, and 'UR and 'LR to the rightwing. That's pretty much it! However, it was tricky to test because the AI bails when 3 of the 4 ailerons are shot out. So, I modified the two lower ailerons to have airArea = .1 foot (which makes them basically ineffective). Then, I shot out the top two ailerons, and what do you know... no control over roll! I think that we can easily improve DMs by adding this stuff... We can make the wings stronger, since how often would an entire wing get shot off? And, we can make the ailerons weak, so that one or two direct hits will cause them to be screwed up. Of course, if it is possible to modify the range of DOFs, then the ailerons could even get damaged! I haven't tried this for the elevator, but I'm almost certain it will work just the same, and so should rudder. charm
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Spanky the Mad Dog
Pilot
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posted 02-23- 01:15 AM
Thats sounding pretty cool man. I sure hope it works out right for everything. IP: Logged |
Sv
Pilot
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posted 02-23- 09:12 AM
Yes, that was my idea exactly, but here is the down side: your new aileron must be far too ineffective. Ailerons get thier power from the wing they are attached too - so the wing lift increases when the aileron if down and devreases when it is up. Now that the aielron is on a tiny wing, the forces will be much less.One possible way to fix this: Create a special new airfoil that flat-lines when ailerons are neatral, and has very exagerated lift coef for the up/down foil. In theory, if you calculate correctly, this could work... ------------------
-Sv =FC=
WWI in SDOE!
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Raider
Pilot
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posted 02-23- 09:44 AM
Good work charmstar. How did you get the original ailerons to not have any effect? I tried this but when I shoot off the ailerons it acted like it was using the original ones. I do not know what to delete from the wings to stop the original aileron force and still have the ailerons (modified with airfoil) move. Do I need to set up some kind of dof for this? I really want to add this to our plane. ThanksRaider {GS} IP: Logged |
Sv
Pilot
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posted 02-23- 10:14 AM
Just make sure you kill the airControl and airObject prop lists...-Sv IP: Logged |
Whirlwind
Pilot
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posted 02-23- 10:44 AM
Great job! I was wondering about this. Now you can make the airfoil a child of something else to sim control likes. Here is the chain of thought, non original, and derrivitive from several other threads:- Create two airlerons per normal airleron.
- One airleron has no airfoil properties, just damage and a dof linked to the wing.
- The other airleron is obHidden, and attached to a obHidden control point where you want the control line at. This airleron is possitioned in the exact same spot as the first one.
- When the control structure is destroyed, obDetach the hidden airleron.
- Both airlerons and the control structure should be part of a nonmoving obHidden object, that is located in the exact same position of the airlerons, so that when the airleron is shot off, both airlerons go. Walla, shootable control lines. IP: Logged |
jedi
Pilot
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posted 02-23- 11:25 AM
Having an aileron actually shot off seems unlikely to me. BUT, having one shot UP seems pretty possible. What if you put TWO "obHidden" ailerons on there, each half the size of the original. Let ONE get shot off, and you should lose HALF the aileron "power." Then replace the visual, moving, (but non-aerofunctional) aileron .lod with a "shredded" aileron.Or maybe do two aileron pieces, but one is 25% of an aileron, and one is 75%. Let the "big" one get shot off, so that only the little one still works. Just brainstormin here... ------------------
--jedi-- IP: Logged |
charmstar
Pilot
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posted 02-23- 01:43 PM
SV- I extended this idea to the elevators, and I can say that the modified SE5a flies just fine (IMHO). I bet you are right that there will be some difference, but it seemed to work for me.Jedi- I know what you mean about the likelihood of actually causing the aileron to detach, but I have to admit that shooting down a plane is more rewarding when you see parts of it falling off. :-) Anyhow, another possible way to model damage to an aileron would be by changing the airRuntime property. I don't know if this can be specified at any point or if it is hardwired for the model, but that would be easy to test. Anyhow, you could not specify airRuntime at first, which will cause it to take its default value. Then you could have some onDamage prop list, maybe calling an obProb with say 3 different outcomes: aileron runtime not affected, runtime = 5s and runtime = 500s. Making it 5s would make the plane MUCH less responsive to roll, and making it 500s would effectively cause the aileron to be locked in its current position. what do you guys think? charm IP: Logged |
bjorn
Pilot
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posted 02-23- 02:39 PM
Charm,Tried that, it doesn't work. You set those properties once, and cannot alter them, unfortunately. MH said, quite some time ago, that he had changed that, but since then it sounds like he's been extremely swamped with work. Hopefully by the next beta drop, which fortunately begins to sounds like it could come out soon.
_
/Bjorn. IP: Logged |
Bryan Russell
Pilot
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posted 02-23- 05:32 PM
My take on the ailerons thing was that the actual ailerons were just eye candy and the actual modification of lift was done by interpolating between the up and down airfoil data that was assigned to the wing airfoil. If this is the case then I would expect that you would still see some roll happening even after the airfoil enabled aileron was detached. I would have thought that you would also have to modify the airfoil data for the wing so that the up and down data was either deleted or the same as the normal data. Also, in the planes I've seen there are no DOF props for the ailerons, and they were moved because of the association in the wing airControl properties. Did you need to add some DOF props as well?
I've just read this after I've posted it and it sounds a little negative. It isn't meant to be, just that I didn't think it worked this way 
Bryan [This message has been edited by Bryan Russell (edited 02-23-2000).] IP: Logged |
Elric
Pilot
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posted 02-23- 06:13 PM
Charmstar, nice one! This is way to do although you'll pay the price in CPU cycles. sv : RE "One possible way to fix this: Create a special new airfoil that flat-lines when ailerons are neatral, and has very exagerated lift coef for the up/down foil. In theory, if you calculate correctly, this could work..." The airfoil for the ailerons would need to changed as the airfoil section on a control surface will be more or less symetrical. The up and down values would not have to be changed because they are only for interpolating the lift etc for the airControl object. The aileron is basically a like a wing with no control surface the DOF controls the Angle of Attack for the aileron. I thought of doing it with the mossie a long time ago but it was beyond me. Brian, you are correct but the ailerons do you DOF's. You don't have to modify the up and down data because it won't be used in the equation. Damage modelling the aileron : Don't use obHidden airfoils, they have effect when hidden, use obModels ( see OP docs ) to swap in a less effective aileron. Elric
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charmstar
Pilot
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posted 02-23- 06:40 PM
Well, sounds like a bunch of skeptics here :-) Actually, it is true that it's hard to verify this works. I tried some dogfights, but even though I aimed for the wingtips, I was only able to shoot out one aileron. Anyhow, the way that I ended up verifying it was twofold. First, I flew the SE5a with the modification to both the ailerons and rudder, and it seemed fine to me (but I'm no expert). I also modified the Dr1, and had a nice dogfight going, the planes didn't fly like pigs or anything. Next I modified the SE5a again, to make the two lower ailerons each have wing area = .1 feet. Then, I set up another mission, with the SE5a on the ground. I went into slew mode, and shot out the top two ailerons. Then I entered the cockpit, and tried to take off. The plane managed to get airborne, but it kept rolling gradually over to the left. I was unable to correct with the remaining ailerons, and crashed. So, I think it works. I also think that this will more obviously manifest itself in planes with only two ailerons, where getting one shot out is a much bigger deal.
Oh, I don't know what the hit in CPU cycles is, but I bet it is significant, because with the rudder, two elevs, and four ailerons, we're talking about 7 new airfoils for the SE5a. Other planes would have 5. My 4v4 dogfight was kind of choppy at times, on a PII-400 with 64megs of RAM, and 16meg TNT, and Win95. I didn't test a 4v4 without the modifications though, so it could just be my system :-)charm IP: Logged |
Sv
Pilot
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posted 02-23- 07:43 PM
I believe you charmstar  Bryan,
The aileron data (foilup/foildwn) is only used if there is an airControl object I think. So if you delete the airControl property and the airObject property then there should be no interpolation on the up/dowm charts. I have not tested this yet, I would hope that this is the case. Also as far as I know ailerons MUST have a DOF or they will not move. Elric,
Good point. That is what I kinda meant to say. But about this point: I think a real attached aileron would be more effective that just a deflecting free-floating aileron. In other words the wing would magnify the effect of the attached aileron. Example: if you just tore out the aileron and moved it 10 feet above the wing. Now try to roll. I bet the aileron would not be able to overcome the roll dampening of the wing very easily. Right? When the aileron deflects on a wing it changes the whole lifting charecteristic of the wing. Right? Now TS, don't beat me up to bad Still all in all, this fix is not worth the FPS loss and spagetti code. This should be an OpenPlane enhancement IMO. Or maybe I'm just to damn lazy -Sv IP: Logged |
Bryan Russell
Pilot
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posted 02-23- 08:03 PM
For the DOF thing I meant DOF proplist, is there something that needs to be added there?IP: Logged |
Sv
Pilot
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posted 02-23- 08:24 PM
No, nothing. You will find a DOF ID prop list there on my Albatros - this is only so the moving control stick knows what DOF to use...-Sv IP: Logged | |
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