[WIP] AHFM - Advanced Helicopter Flight Model

[leftskidlow2 10]

Neat idea. If you are going to put an emphasis on the effect of wind then probably then biggest though on a helicopter pilots mind is translational lift and it's increased effect when taking off and landing into the wind.

It seems like it could be done with something like: if indicated airspeed < 16 knots, then maximum available power = 85 %

I also wonder if limiting the maximum available power could simulate payload. Something like every solider onboard reduces max availible power by 1%.

There are a lot more experienced pilots on these forums then myself but if you need any technical input feel free to ask, I was a civilian helicopter CFI about 5 years ago.

[FredAirland 13]

Ideally I would like to implement my own helicopter physics engine but this would probably require some direct Acces to Physix headers to make a clean job. There's probably some headers hidden in the PBO's but I have no clue where to find them....

If the engine is still Rlib I can probably make the changes quite fast....

[.kju 3240]

There is just the Rlib configuration files - the engine part is not active/has not been ported to A3 (yet - if ever).

[FredAirland 13]

So Rlib files are not used at all ? Do you know where the HelicopterX dll is or if there is a way to create your own VehicleX dll ?

[.kju 3240]

They are not used at all correct. In A3 you cannot/can hardly tweak the helo FM via configuration files.

Its probably still mostly down to the mass distribution in the model.

There is no dll for the FM in A3. You can attempt to use scripting and the extension interface to connect to outside the game (ie for faster computation).

However you probably cannot achieve too much that way.

[stevos758 10]

Subscribe!!!!

---------- Post added at 03:31 PM ---------- Previous post was at 03:28 PM ----------

You guys should also get this guy involved....

http://forums.bistudio.com/showthread.php?162022-Advanced-Cockpit-Interaction

[Fushko 60]

That looks ambitious. Keep it up :)

[gatordev 215]

None of this auto-hover bullcrap, maintaining a hover should be a delicate dance between collective, pedals and cyclic.

This isn't really true. It greatly depends on the aircraft you're flying. For light civil, yes. For a lot of military (and heavier civil) helos, you can hover with (mostly) no hands on the controls. In fact I regularly fly an approach to a hover, at night in IMC conditions, without touching the controls (well, except for pushing the button to initiate the approach/hover). I can then push another single button and it will transition from a hover to 120 knots (or any airspeed of my choosing below that) completely on it's own.

I mention this because trying to make one-size-fits-all model based off a Robinson or Schweitzer and comparing it across all different models in-game is just going to make no one happy. Should the MD-500s be "dainty?" Sure. Should a -60 derivative? No, they're pretty solid and very easy to fly/hover. Balance will be the key.

[R. Brown 10]

well said

[ZimZamFlimFlam 10]

This isn't really true. It greatly depends on the aircraft you're flying. For light civil, yes. For a lot of military (and heavier civil) helos, you can hover with (mostly) no hands on the controls. In fact I regularly fly an approach to a hover, at night in IMC conditions, without touching the controls (well, except for pushing the button to initiate the approach/hover). I can then push another single button and it will transition from a hover to 120 knots (or any airspeed of my choosing below that) completely on it's own.

I mention this because trying to make one-size-fits-all model based off a Robinson or Schweitzer and comparing it across all different models in-game is just going to make no one happy. Should the MD-500s be "dainty?" Sure. Should a -60 derivative? No, they're pretty solid and very easy to fly/hover. Balance will be the key.

I feel like you should be working with Brainslush on this

[FredAirland 13]

mention this because trying to make one-size-fits-all model based off a Robinson or Schweitzer and comparing it across all different models in-game is just going to make no one happy. Should the MD-500s be "dainty?" Sure. Should a -60 derivative? No, they're pretty solid and very easy to fly/hover. Balance will be the key.

they way I solved this in my HTR library (for FSX) is to implement an AFCS (Automated flight control system) on top of real helicopter aerodynamics, which is what is present in larger helicopters. So basically the aerodynamics are true but you have the AFCS taking care of making the helo do what you want.

[gatordev 215]

I feel like you should be working with Brainslush on this

I can read some code, but beyond that, I'm pretty useless on the modding side...other than testing.

they way I solved this in my HTR library (for FSX) is to implement an AFCS (Automated flight control system) on top of real helicopter aerodynamics, which is what is present in larger helicopters. So basically the aerodynamics are true but you have the AFCS taking care of making the helo do what you want.

Which is exactly how it works in the real world. I'm not sure how robust the A3 engine is to do this (see above), but based off ToH, it seems very likely...assuming the library is accessible.

[brainslush 13]

http://feedback.arma3.com/view.php?id=15211 Up Vote Pls

[enex 11]

Upvoted.

[brainslush 13]

Hi brainlush,

I did some FM helicopter editing for TKOH and just purchased ARMA 3

Why do you say Arma 3 doesn't use RLib ? by unpacking the files in air_f.pbo i can still find the rotor lib configuration files like Light-GenHeli600-DesktopSim.xml and such, so I think HelicopterX probably still uses rotorlib...

anyway I am quite experienced in Helicopter FM, let me know if you need help...

bye

Fred

As .kju [PvPscene] said the config-files are there but since BIS wasn't able to fuse PhysX and RTD the RTD part is still disabled.

I hoped that this project would be far easier than it actually is. The biggest problem are the restricted commands which BIS provides. The only useful command so far is the setVelocity command. I hoped that BIS would already have given access to some PhysX commands which would make this whole thing much easier. Apparently they didn't.

I even thought about programming an external dll which directly accesses the memory and modifies it but I think BattleEye won't allow this since this is a common way which cheaters use to hack the game.

[FredAirland 13]

since BIS wasn't able to fuse PhysX and RTD the RTD part is still disabled

I am working on an HTR version that works with Physx in Unity, and see no probems, maybe if the open up the flight model as DCS does ( adding an HelicopterX template and exposing the Physx headers) I could do something, I believe in any oher way you will end up fighting between your physics and the default ones...

[martinezfg11 334]

@gatordev are you a pilot irl?

[gatordev 215]

Yes....

...Stupid min character limit.

[samb 15]

Hello! I totally forgot about Arma since developers dropped pre release idea about TOH flight model. I just did a quick search to see if anything changed, and here it is! It is a great news, the best I've heard since UH-1H and Mi-8 for DCS. Hope Fred will be able to assist You, so we get an awesome mod for helicopter enthusiasts. I will be watching the progress very closely!

[FredAirland 13]

I believe that the FM of Arma 3 is not that bad, especially for modding, it is easier than TKOH...

I am currently working on a series of "effects" to make it behave very much like HTR,

nothing as complex as HTR but from the user perspective you should hardly be able to see the difference... then if Bistudio releases some more access to Physix I could do better...

still digging in the wiki and such...

I was wondering if there is any gauge documentation anywhere. As I understand in Arma Gauges are 3d objects with animations, but how do you control them ? (still a newbie)

[samb 15]

Fred I really wish I could help You guys, but all I can do is keep my fingers crossed. My only experience with modding was 7 days wasted trying to use Arma 2 helicopters with TOH FM. With no documentation it was just guessing game, and I got some helicopters working while some were not for no apparent reason.

[brainslush 13]

@fred

I guess what you want to do is to animate the gauges for the engine temperature, rpm, torque and similar stuff, right? There isn't much to control since there are no values which you can access to set the gauges properly. Those are controlled by the game engine and the displayed values are far away from the realistic value. I guess most gauges do have a standart animation which starts, when the startengine eventhandler gets fired.

In TOH the values for the gauges where calculated by the RTD and much much much better.

[FredAirland 13]

@brainslush

thank you, I was thinking more about displaying my own values in the gauges, i.e. I will make the calculation and send the value back to them... do you think it is possible ?

This weekend I worked on a beta of the script, I currently have implemented:

- ground effect

- vortex ring state

- translational lift

I would like to know if there is a way to read the input values for cyclic, collective and such, this would help a lot.

Also I believe there is no easy way to set helicopter angular velocities (i.e. pitch, roll, yaw velocities)

Please vote THIS on the feedback site as it would greatly help.

Also I am currently facing a problem at high speeds since the script seems to slow down the update, maybe it is due to the script running too slow ? (it is less than 50 lines so it shouldn't)

anyway I'll publish a beta mission in the next few days...

Bye

Fred

Edited October 14, 2013 by fred64

[toxicsludge 12]

This all sounds very exciting, I wish you the best and will be keeping my eye on this one :)

[gatordev 215]

A request, if you're interested... Don't overdo Vortex Ring State. EECH had it way overdone (as a data point) and it's really not something that's all that big a deal in normal ways to fly a helo.

That said, looking forward to the beta.