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Grayeagle

Flight Modeling

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Hiya!

Lets talk about the flight model :)

Control input in an aircraft is a matter of pressure applied.
When you pull the stick back the nose rises.
When you increase the pressure applied, the nose rises faster.
When you ease the pressure, the nose rise slows.
It is a direct, linear response.
Right to the point of accelerated stall, exceeding the angle of attack the wing will fly at.
Torque and P-effect take over at that point. (can be exciting :D )

A fighter aircraft's primary design goal is to be a stable gun platform.
They don't bounce unless told to.
(well ..unless you fly into the base of a thunderstorm,
..then your mileage may vary)

Some may say this is opinion ..
..well .. educated opinion and experience.

-4.0 GPA during 2yrs of Aeronautics at Embry-Riddle Aeronautic University long ago.
-Couple hours here n there doing aerobatics and boring holes in the sky
 ..inluding an hour of aerobatics in 'Crazy Horse' .. a TF-51D Mustang.
  (power on stalls, accelerated stalls with/without 10 degrees flaps in extreme right/left turns
   pulling through till she broke ..exciting!) ..also did simulated ground attack runs, pop-ups, strafing, FUN! (400ias below the tree tops!)
 ..also aerobatics in a PT-17 Stearman, a bit of fun in an Aeronca Champ,
 ..and some point-to-point in Cessna 172 which I learned to fly in.
-coupla dozen hours in various USAF sims, mostly the F-4 sim.
-built and flown my own designs, Radio Control and U-control, since high school (early '60's)

Since a desktop simulation cannot model the pressure required to pull G's..
 (ie: a normally trimmed P-51D requires 50lbs of pull per 'G' pulled ..
  ..2g requires 50lb pull, 3g needs 100lb pull, etc
  ..you need to trim the aircraft to pull 9g unless you are in *very* good shape
  ..full brace with both feet, both hands, pull for your life.. 400lb pull.

..it would *rock* if the devs could make the control input a bit more linear.
 
There was a game long ago called Air Warrior that had it right.

-just sayin

-Frank P. 'Gray Eagle' Williamson
 

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I do not doubt that what you are saying is true. You seem to have a great deal of experience. 

 

However, I do not understand the meaning of making the control input 'more linear'. Is it not already possible to adjust the curves in the control settings to suit your needs?

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I cant tell if you want the control inputs to always be linear and disregard modeling limited control inputs as speed increases due to the weight. Because as it is now the controls arent able to be deflected all the way when the speed increases but you cant limit a customers stick deflection so they have to change the curves to model this limitation. Are you suggesting the control input always be the same and then 'stop' at the point where it would require too much force to move the stick? A more accurate way to model this would no doubt be a force feedback stick that increases resistance as the speed of the plane increases but as I understand force feedback does not work in this way nor is there a consumer model stick to represent 100lbs of force. 

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If I were to build a force feedback stick that realistically limits motion by providing large resistance, would I be able to make it interface with the game correctly? The mechanical design is simple enough, but I do not know if there is a way to dereference something in the software to get the stick force data.

 

Designing a strong force feedback stick would certainly be an interesting project. I suspect I would first have to learn more about a certain API to get the game to 'talk' to the stick. 

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@Field-Ops - of course force feedback joystick stiffness as speed increase.

It would be interesting to have build in the game human limit model. For sure it would make game more realistic and natural when view from outside. Many times I sow insane maneuvers or sustain high Gs - one after another. New FM patch make this thing happened rarely, I don't know if further enhance is needed - maybe little tune-up. Any way sustained G and human limits are interesting. Btw in DD 120 there is announcement for something about more realistic response for pulling Gs.

Edited by 307_Tomcat

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Greyeagle, what is your point? Still too much „wobble“ (induced pitch / yaw oscillations by sudden control inputs)?

 

What you are stating about the stick force in the P-51 will automatically translate in a non-linear input for a sim once you have to translate a 200 lbs stick force into the average chinese pice of plastic. Would you call it realistic if you could pull 400 lbs stick force with two fingers? Naturally, inputs have to be capped.

 

Getting a good joystick will help a lot in getting a better control of the aircraft in the sim. Previous combat sims were not nearly as sensitive to inputs as this sim.

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Which is why I only fly with a force feedback stick and greatly appreciate the stick getting harder and harder to pull as I gain g ...

I switched off the FF as an experiment last week and suddenly I was trying to control an aircraft with a sloppy piece of spaghetti!

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Which is why I only fly with a force feedback stick and greatly appreciate the stick getting harder and harder to pull as I gain g ...

I switched off the FF as an experiment last week and suddenly I was trying to control an aircraft with a sloppy piece of spaghetti!

Best test is turn off in game FF and enabled it in external program (forcetest.exe) for emulating just spring force. Flying limb Joy is rediculus.

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I guess I wasn't clear enough .. in game, level flight ..no control input ..aircraft trimmed for the speed it is flying at.. the nose wanders up, down a bit side to side..

..if I pull the nose to a target, it continues ..up, down, side to side ..not much, just enough to make it more difficult than it should be.. leads to a lot of over-correcting and missed opportunities.

 

Even the Aeronca Champ I flew did not do that.

(fabric covered 1930's vintage high wing monoplane, stick and rudder controls, takes off at ~28mph, cruises ~35mph ..and such, very similar to Piper Cub)

 

Yes..I know of joystick scaling in the game, I am still tweaking that to suit me and what the game offers.

I dont have a force-feedback stick.. so 'sloppy peice of spaghetti' is close for the description of what it feels like.

 

By more linear I meant not as much wandering from flight path ..a bit more steady.

 

I use CH Fighterstick and CH Throttle ..not many better out there.

 

I know aerodynamic forces on control surfaces increase when airspeed does, and vice versa.

I fully expect compressibility affects at high speeds and mushy washouts at low speeds. (hello TREE!!!)

 

Just saying that the aircraft should be smoother in response ..pull this much, nose rises at this rate ..very little plus or minus to that in any axis.

It is easy in a Mustang to center your viewpoint exactly on a spot and pull to it when you are working at nominal manuevering speeds.

Same with a Stearman biplane, Aeronca Champ, or Cessna 172.. about the most different flight envelopes there are for prop aircraft.

 

-just sayin

 

-Frank

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There used to be a lot of bounciness, I honestly don't feel anything that you are describing in current FMs though. Isn't this just a consequence of your stick or input curvature? Input feels smooth and linear to me on every single plane in the game.

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I use CH Fighterstick and CH Throttle ..not many better out there.

 

 

-Frank

I'm afraid you are behind the times, even though I still use a CH stick, there are much better sticks out there now. Check out Virpil, VKB, Baur...

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Grayeagle, the „wobble“ you‘re talking about has been mended a lot in the last patch. Consider it a simulator disease. Making things even harder. Players seemed to take this difficulty for realism. Planes that just point to where you point the stick are often deemed „to fly on rails“ and supposedly have a bad FM.

 

I do agree with your statement. But it is already much better now. But a good joystick helps as well. You just can‘t cure years of habits and expectations just like that. ;)

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Yanno .. it may be that I just have not found the sweet spot of stick scaling settings ..I *am* a dweeb :)

 

Some of video's I watched show pretty rock solid pull, aim, shoot bits .. it will be awhile before I can play 'through' the interface (not thinkin about what button to push, just doing it)

 

-Frank

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I flew with CH products for a long time. They are nowhere near state of the art anymore. All of the high end sticks, for the most part, are better.

 

I've done a little formation and aerobatics in the Collings Foundation B model. I was amazed at both the responsiveness and the stick forces involved. The aircraft flew more on rails than I would have expected. That said, the sim is rather good at the overall feel of flight and I'm satisfied for the moment. A better stick will improve your experience considerably.

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The CH has low resolution potis from what I know which are prone to deliver inaccurate input and have issues with jittering (especially around the center). To really get good results you have to upgrade to a modern standard contactless sensor stick with adequate input resolution. Having a stick extension to better reflect a real aircraft's stick also helps a lot to physicly smoothen the input and making the aircraft 'feel' more stable.

 

Flying wise I have moer than 200hr of glider expirience and a couple of hr on different motor planes to compare with this sim. In my opinion this is as close to real flying as you can possibly get at the moment.

 

With that said I've flown in this game with a Saitek X52 Pro, Speedlink Airrow and TM. 3D Pro. The last one is by far the worst since it also uses low resolution potis. The only reason I got it is because I was low on money after having the first 2 break down. Putting a custom 7cm extension on the thing and modifying the gimbal helped as well as applying some sensetivity in the controll settings.

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I can only recommend my innexpensive TS16000...

 

OTOH, I still do find the pitch wobble in most of the aircraft, the only exception probably being the Spitfire where the neutral pitch stability is modeled in such a way that it behaves pretty much like I would expect on other models...

 

I do not have any real life experience in any of these aircraft, but I know for sure that sudden inputs in pitch in my glider, or any of those I've flown along my life, and return of the stick to the trimmed neutral, will not result on such sudden pitch osccilations...

 

But on a completely different matter, Rudder stiffening with "q" feels well implemented in IL2 IMO.

Edited by jcomm

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I've done a little formation and aerobatics in the Collings Foundation B model.

 

A bit of an eye opener isn't it? I found real life flight has an excellent frame rate, color saturation was spot on, and the control 'feel' was amazing.

I would expect the B model Mustang to be a bit more responsive throughout it's flight envelope than the D model from what I have read and chatting with Mr. 'Bud' Anderson (Old Crow) long ago.

 

So you know exactly what I refer to ..the feeling of being on rails describes how it reacts to control input perfectly.

I learned to fly a few years before civilian video flight sims were available, so was always a bit put off by most.

 

Gliders are something I always wanted to try ..just never got around to it .. amazing aircraft!

 

Bit of a shock to have people say CH is nowhere near the best anymore .. they are well over a decade 'old' and still perform well.

36 separate functions ..and 3 'modes' to operate in, allowing over 100 functions... just on the Fighterstick alone.

I did notice the 'jitter' and tuned it out completely with sensitivity setting under the input devices tab in settings.

Also checked out Virpil and the other bits mentioned.

.006 degree sensitivity !! ..ya .. CH isn't in that ballpark at all. I may have to win the Lottery :)

 

It will take me awhile to get the aircraft to respond as close to what I know it should with the very nice scaling doo-dad for axis controls.

 

Gettin closer tho .. slow but sure.

 

Still plannning out functional grouping ..what should be where ..fitting in my 'old habits' :)

 

Thank you all for your insight .. trying to learn as much as I can.

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Bit of a shock to have people say CH is nowhere near the best anymore

 

 

The CH has low resolution potis

This...

 

Newer sticks with higher resolution will just give you so much more precision. A stick extension helps, too... I have a 10cm extension on my TM Warthog, and all planes feel like stable gun platforms.

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Curious about your settings in game for the CH stick Greyeagle, I've been running mine for 14 odd years now, and I too still have some of the on center "wobble", though it is better than it used to be.

 

I only have about half an hour in a Stearman, but even that short hop was enough to sort of put me off flying the sim.  It just isn't even close to real flying in a responsive aircraft.  Too "loose" feeling, as if the aircraft was hanging suspended by rubber bands, and a giant finger is flicking the wing tips with every control input.   I've always described it as feeling like the aircraft have no mass, which automatically brings out the "flying on rails is wrong" comments from the "harder is more real" crowd, so I just don't say much, or fly the sim much anymore...

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Curious about your settings in game for the CH stick Greyeagle,

 

Settings are very much a work in progress atm ..

 

WTG on flyin the Stearman .. my ground school instructor owned hers.

One fine day at a Madera Warbirds show long ago, after the show was over, she asked if I wanted to fly it.

Very silly question ..man I wanted to fly *everything* :)

So I asked her what was best takeoff, landing, approach and cruise speeds were.

She laughed ...and said 55mph, 55mph, 55mph, and 55mph :)

We went up north of Bakersfield (California) ..and looking down over the side

.. cars on Interstate 5 were going faster than we were.

Went down low, buzzed some radio towers (actually flying between and around them, barnstorming stuff ..FUN.

.. after workin the bird a little and getting to know it a bit.

On landing approach I was delighted that the flying wires give a very pronounced tonal signal when you near stall, it's very easy to hold it there

..some have said if the wind thru the wires begins playing 'Nearer my God to thee' you are too close to stalling :)

 

Anyway .. Sensitivity under Input devices I currently have set all the way to the right ...no jitter anywhere in any axis with one caveat.

When you move the stick there is a slight lag in control response ..as if you are moving a paddle thru thick oil.

Duplicating exactly what happens in a Mustang flying at best manuever speed.(250IAS)

..you cannot 'slam' the stick to full deflection ..you brace your arm and push as hard as you can

..ie: doing a 360 degree roll I pulled the nose up about 15 degrees, then braced my arm 90 degrees and pushed hard to max deflection to do a roll

..by the time the stick hit the stops full left we were inverted, the roll rate accelerated to that point, beginning gradually and building to max roll rate.

When we reached upright level flight I just stopped pushing and the aircraft stopped rolling exactly at wings level.

No overshoot, no nose wobble ..on rails all the way through with the nose dropping to level gradually during the roll.

 

For stick scaling in main controls tab, under keymapping, i use an 8% deadzone in center and edges both

.. so when stick is centered it stays there until I want to move it

..and when I want full deflection it goes right to the limit and will stay there also.

 

The rest I am still experimenting with ..using a straight linear response to a pronounced 'S' shape

..kinda leaning to a small 'S' shape in response curve to make input near the center of an axis more precise to mirror what you do when you fly.

Small corrections are all that is needed for most flying ...aerobatics require a bit more for a fact ..as I imagine dogfighting does also :)

 

-Frank

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I had to borrow a coat as it was a cold day to be in an open cockpit :) This is Bertie's Stearman. I had 3.5hrs of dual in my pilot's log when she asked if I wanted to fly it :) A brave lady, she flew backseat and let me horse the bird around in the front for about an hour of pure fun :)

post-145451-0-50097200-1509720785_thumb.png

post-145451-0-43528400-1509720883_thumb.jpg

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HHcy5e.jpg

 

Me in front of the one I flew.

 

Thanks for the info on stick settings.

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Sorry for the OT,

 

but I  am really pleased to see many RL drivers sharing interest for this AMAZING flight simulator.

 

A good example is Syn Requiem, which after his hiatus due to getting into the RL business of airline flying, returned and returned to nothing less than IL-2 Battle Of ... 

 

For some reason we prefer this sim :-)

 

Even if it still has, as anything in Life, it quircks ...

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Sorry for the OT,

 

but I  am really pleased to see many RL drivers sharing interest for this AMAZING flight simulator.

 

 

 

Drivers or PILOTs ?  what do you mean?  :rolleyes:  ;)   use or abuse of google translator?  :P  :biggrin: 

We are many sport PILOTS, and aircraft mechanics here. .. I´m afraid that, we are more than devs thinks.  ;) 

 

Edited by III/JG52_Otto_-I-

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Drivers or PILOTs ?  what do you mean?  :rolleyes:  ;)   use or abuse of google translator?  :P  :biggrin: 

We are many sport PILOTS, and aircraft mechanics here. .. I´m afraid that, we are more than devs thinks.  ;) 

 

 

Yep, they're ( 1C / 777 ) a small but Wonderful Team !

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LOL Blitz ..nice beard dood ;)  ..and a fine lookin aero-plane behind you.

 

I am a lil scruffier than I useda be :) ..and that is Brutus, in my shirt pocket ..best guard dog *ever* -grin-

 

-Frank

post-145451-0-53491300-1509999918_thumb.jpg

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I’ve heard many a pilot referred to by the slang term driver, Mustang driver, Thud driver, Snake driver, etc. I’m comfortable with the term.

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Yeap, that's my perspective HerrMurf...

 

Most aeronautical vehicles are driven, not flown :-)

 

I even say I drive my glider... I'm a glider driver... 

 

I would fly a paraglider, even a delta wing still fits, or one of those scarry wings some guys carry on their back and fly with...

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Udet took it as a deliberate insult being called the „driver“.

 

It shows the increasingly casual attitude towards piloting an aircraft...

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It's the delay between control input and simulated output that contributes to your feeling. Same for throttle settings (as I'm an engine nerd too).

 

Check the stick movement as depicted in the sim. You give your control a full deflection movement, say it's a right roll - and it takes four seconds for the stick to slowwwwly move to its rightmost deflection. No loss of airspeed to account for reduced stick forces or something either.

 

In my experience, my muscles don't work like that. They give me everything they got when I tell them to, right away.  :) 

And if what they got ain't enough, I know that immediately, too.

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I use CH Fighterstick and CH Throttle ..not many better out there.

 

:huh:  CH still a twenty century product - and we are in the seventeenth year of the twenty-first century, look at specifications of the "Next Generation" of controllers for flight games, made by Baur, GVL224, MFG, Slaw, VirPil, VKB. ;)

Edited by Sokol1

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Compared to the other approaches I have experimented with, in 

 

- MSFS

- X-Plane

- Aerowinx PS1 and PSX

- ELITE

- IL2 CoD

- DCS

- Condorsoaring

 

I honestly find the implementation / representation of control stiffening in IL-2 is by far the most effective / realistic, withing what's possible to do for users without "proper hardware" :-)

 

I don't feel anywhere near other than in good old Condorsoaring ( which allows for a nice fine tuning of control forces )...

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Ok . . input device sensitivity .85,

Control axis sensitivity at 40 percent

8 percent deadzone at either end to ensure the stick input reaches max deflection

4 percent deadzone in the middle

 

These settings come closest to duplicating the 'feel' of being on rails, for my setup.

I am trying not to be so ham-fisted with the controls, especially on final ..training myself to be smooth will take a bit yet :)

 

Actually managed to hit something with 500lb bombs tonite on Wings of Liberty server ..learning the Pe-2 ..love the speed :)

 

-Frank

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your complaints seem familiar to me, as in: How it was for me before I "upgraded" my x55 stick.

 

 

First advice, check your noise filter setting - that's in the input devices menu, not key bindings, mind you.   set it at zero for a 1:1 response.

 

You can adjust that up gradually if you find the stick has become too "twitchy" - but that should remove the "delay" you mentioned, perhaps.

 

 

Another thing, I personally dislike deadzones. If you feel you need them, it could be said that perhaps there is something wrong with your joystick.  It is quite possible a small (but ultimately huge) slack exists in the gimbal.  Even the slightest amount of play can lead to the sensation of "flying spaghetti". I am thoroughly familiar with what you mean by that.

 

 

My X55 had a lot of slack in its shittly built plastic sweat-shop gimbals.  Most unfortunate.  It made for precarious flying, requiring deadzones, curves and heavy noise filter to overcome. Even so, only partially.

 

What fixed it, was handyman's best friend:  Duct Tape.

 

I took my stick apart, completely.  Disassembled the entire gimbal down to it's last moving part.  I could then scrutinize the assembly and determine there was way too much space between the gimbal pins and mounts.  This allowed them to move, less than half a millimeter in places, but that was enough, see.

 

I then proceeded to wedge small bits of Duct Tape in between these slots, sticky side facing outwards from the pins against the rim of their mounts, so that the adhesive did not interfere with the gimbal pivoting action. 

 

Thus, the thickness of the tape filled in the gaps, ensuring there is no room for any movement besides the intended gimbal rotation:  Zero slack.

 

Surprisingly enough, the lever arm length of the stick is such that no lubricant proved necessary.  While the tape-filled fittings were so tight that they felt almost too hard and grippy to me when manipulated directly with fingers, they revealed perfectly smooth and soft when operated normally with a firm hand on the full reassembled stick.

 

With all the gimbal slack removed, I was then able to set all deadzones to zero, and all axes to fully linear.  It feels more precise now than ever before.  No noise filtering is needed.   It is a whole new experience in full.

 

Even my combat record in the stats shows a near magical overnight improvement. My aiming ability has increased by a full order of magnitude, it feels.

 

I did also extend the arm of my stick by about a half inch.  It added half again the movement range for the stick, making everything vastly more controlled.

 

 

Another point to observe,  ensure the base of your stick is firmly secured to whatever surface it's mounted on.  Ensure also that surface does not wobble even slightly as you move the stick.  Wedge objects under it if necessary to stop any wobbling. Use C-Clamps also, screws, bolts, tape, whatever. Anything to make your stick base rock solid. 

 

Suction cup "feet" are not adequate fastenings, although many a joystick ship with them for that very purpose.  Being made of rubber allows them to gently rock the base a few degrees under the motion of the stick.  A subtle, but critical handicap, to blame for a horrifying sensation of "rubber bands for control cables"

 

One's joystick should move ONLY in the two axes that control the airplane (or three, if you need a twisty).   Any movement that does not map directly to flight controls as per design is unwanted, and must be removed.

 

The difference a decent setup makes in your flying "skill" is past unfair, in a combat setting.  VKB sticks with their unfailing metal gimbals yield more than a trivial advantage. 

 

 

Luckily for the rest of us, there is Duct Tape

Edited by 19//Moach
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good ideas Moach..

..already found input device sensitivity, hence the statement : 'input device sensitivity .85'

 

I have been experimenting with settings since I installed the game, what I use atm gives the best 'feel' for my control setup.

 

There is still a lot of nose 'bounce' if I move too fast in any axis ..real aircraft have significant feedback that moderates that,

.. in effort required and slamming you against the straps or smashing you into the seat.

 

The delay I mention is in fractions of a second ..higher input sensitivity seems to add more delay from input to controls reaching deflection settings ..

It doesn't mean the axis waits to respond ..it just doesn't follow deflection settings directly ...deflection still begins as soon as a control is moved.

 

The deadzones combined with input sensitivity settings I use eliminate any jitter entirely and allow full deflection in every direction.

 

Throttle control is taped  down hard with packing tape, it used to move when I slammed throttles to idle or full :)

Flightstick doesn't move .. rubber feets are enough :)

 

I still feel that ..especially with an increase in pitch input, the nose should accelerate in a direct linear response ..no 'bounce'

..as a fighter of WW2 is designed to.

 

-Frank

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