Board index FlightGear Support Flying Helicopter

Helicopter realism -- or not? Real pilot tests?

Helicopter flying is completely different from flying a fixed-wing aircraft and thus requires different skills.

Re: Helicopter realism -- or not? Real pilot tests?

Postby mfranz » Thu Jun 17, 2010 10:05 pm

HHS wrote:When I shortened the nasal-file, I must have missed something. I didn't found out yet what.
It is the second time that I hear that Linux behaves different regarding Nasal :|


That's neither an Operating System, nor a Nasal issue. You didn't copy essential parts of bo105-set.xml. Hint: look at the <controls> block, especially /controls/engines/engine[1]/throttle.
User avatar
mfranz
 
Posts: 160
Joined: Thu Nov 30, 2006 4:35 pm
Location: Austria

Re: Helicopter realism -- or not? Real pilot tests?

Postby HHS » Fri Jun 18, 2010 12:34 pm

Thanks Melchior,

I knew that I did miss something, But I always thought that I didn't understand something in the nasal-file correct and so copied wrong. But I never thought that I simply forgot the part in the set-file. Thanks for the hint!

I just wondered why Groucho got a different behaviour then.... no matter well, it isd solved, Thanks!

Regarding startup EC135: I only had a short look into the function of engine control some months ago. So I told yesterday something wrong.
Ignition is controlled by the FADEC. So if a FADEC-filure occurs during flight, the pilot can adjust the power etc.with the twist-grip on the collective.
If the FADEC-Failure occurs on the ground before startup, it isn't possible to start the engine. But the FADEC is redunant, so this case should not happen often.
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: Helicopter realism -- or not? Real pilot tests?

Postby ranger8 » Mon Mar 28, 2011 3:56 pm

Hi guys,

I just joined the forum, haven't even downloaded fg as of yet. I currently run fsx in a simulator I built out of a salvaged R22 cockpit. Fsx (after many addon's and tweaking) does a fair job of modeling the proper flight dynamics, and a more than fair job for procedural training. Where FSX fails miserably is in the throttle/governor/collective modelling area. FSX uses the throttle to control lift instead of the combination of throttle/collective pitch. How does flight gear handle this?

Btw, I did not notice any helo pilots on the forum( there may be some, just didn't notice any). I may be able to help in this area, for the R22 or R44 or Bell 206. I am commercial licensed,instrument rated, and all my experience is in these models.
I fly short ride/tour flights here in Oklahoma and Arkansas, along with the occasional larger more commercial jobs.

Let me know if I can help, I will be downloading FG as soon as I get the time, probably this weekend. I spent alot of money on the sim set up, and am very disapointed in the way FSX is performing. But then it may not be it's fault, I'm a pilot, not a programmer. I don't know how commercial simulators like frasca and fly-it have conquered the issues I have, but they did! I used the frasca sim while I was at school, was even able to legally log some of my instrument time in it.

I look forward to hearing from any FG user's that are interested in helicopters.
ranger8
 
Posts: 15
Joined: Mon Mar 28, 2011 3:11 pm

Re: Helicopter realism -- or not? Real pilot tests?

Postby HHS » Mon Mar 28, 2011 4:28 pm

FlightGear uses two fdm's for simulating JSBSim and YASim. JSBSim simulates helicopter since a very short time, so you can't use it in 2.0.0 or upcoming 2.2.0.
I couldn't test it yet.

I will just quote what I have summarized for Curt some months ago:
"In YASim the aerodynamic forces taken in account of an analytic model of the rotor are determined by the BladeElementTheory, everything in real time.
With a large number of different parameters like the rotor and blade specification (see the list in the appendix) all types of rotorcrafts can be simulated realistic.

Torque effect, Ground effect, Translational-lift, Transverse Flow Effect, Dissemtry of Lift, Blade flapping, Gyroscopic Precession,...nearly everything which applys to real rotorcrafts applys to the rotorcrafts in FlightGear as well.

We have only few exceptions, which can't be simulated yet or not detailed enough:
simulation of Vortex-Ring-State, In-Flight-damage like must-bumping and rotoroverspeed, and the engines itself.
"


And to add- some not well configurated models tends to turn on the ground, even with stopped engines. :(

With the Bo105, UH-1 and the Ericson Aircrane we have three helicopters which are based on NASA reports and reacts about 99% like the real ones. UH-1 and Bo105 has been tested by real pilots.One of them, jag007, is sometimes present here.
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: Helicopter realism -- or not? Real pilot tests?

Postby ranger8 » Mon Mar 28, 2011 6:35 pm

Thanks HHS,

There was alot of technical stuff in your post that is beyond my comprehension, but I think I get the point.

I first found out about FG Yesterday, when I googled "pid controller" thats when I found an article about the mathematical theory involved with them by Curt Olson.
Curt seems to have great handle on these complex systems, so i am hopefull that he or someone out there will figure this out.

I would love to work with anyone who is developing in R22 or R44 areas.
ranger8
 
Posts: 15
Joined: Mon Mar 28, 2011 3:11 pm

Re: Helicopter realism -- or not? Real pilot tests?

Postby Groucho » Mon Mar 28, 2011 6:41 pm

ranger8 wrote in Mon Mar 28, 2011 6:35 pm:T
I would love to work with anyone who is developing in R22 or R44 areas.


That would be great. Especially the R22 needs some tweaks and real life experience as its flight model has been targeted by prettty controversal discussions (with model and avionics being pretty close to the real thing).
And I still think of having the R44 and R66 one day ...
_____________________________________
Callsign: D-HARP
Flight locations: TNCM, TKPK, EDNY, LOWI
Aircrafts
Helis: EC130, Bo105, UH-1, R22
Twins/Jets: Aerostar, CRJ-200
User avatar
Groucho
 
Posts: 1216
Joined: Sun Jun 17, 2007 10:28 am
Location: Airborne Lake Constance/Germany
Callsign: D-HARP
Version: GIT
OS: Kubuntu

Re: Helicopter realism -- or not? Real pilot tests?

Postby HHS » Mon Mar 28, 2011 6:54 pm

Yep, the R22 needs some tweaks. And if done, the other two ones can be done in a very short time.

The only current "problem" I see, is that from MSFS to FGFS is big step. We differ in a lot of things....
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: Helicopter realism -- or not? Real pilot tests?

Postby ranger8 » Mon Mar 28, 2011 8:07 pm

HHS wrote in Mon Mar 28, 2011 4:28 pm:FlightGear uses two fdm's for simulating JSBSim and YASim. JSBSim simulates helicopter since a very short time, so you can't use it in 2.0.0 or upcoming 2.2.0.
I couldn't test it yet.

I will just quote what I have summarized for Curt some months ago:
"In YASim the aerodynamic forces taken in account of an analytic model of the rotor are determined by the BladeElementTheory, everything in real time.
With a large number of different parameters like the rotor and blade specification (see the list in the appendix) all types of rotorcrafts can be simulated realistic.

Torque effect, Ground effect, Translational-lift, Transverse Flow Effect, Dissemtry of Lift, Blade flapping, Gyroscopic Precession,...nearly everything which applys to real rotorcrafts applys to the rotorcrafts in FlightGear as well.

We have only few exceptions, which can't be simulated yet or not detailed enough:
simulation of Vortex-Ring-State, In-Flight-damage like must-bumping and rotoroverspeed, and the engines itself.
"


And to add- some not well configurated models tends to turn on the ground, even with stopped engines. :(

With the Bo105, UH-1 and the Ericson Aircrane we have three helicopters which are based on NASA reports and reacts about 99% like the real ones. UH-1 and Bo105 has been tested by real pilots.One of them, jag007, is sometimes present here.


So do I need to download version 1.0 instead of 2.0 to be able to fly the helicopters?
ranger8
 
Posts: 15
Joined: Mon Mar 28, 2011 3:11 pm

Re: Helicopter realism -- or not? Real pilot tests?

Postby HHS » Mon Mar 28, 2011 8:19 pm

No

FGFS, more a real simulator than a game, supports more than one FlightDynamicModel. With 2.0.0 and earlier one only FDM supports helicopters and that's YASim.
Currently all of our helicopters does make use of YASim, so at least 2.0.0 should be fine. But maybe you want to try Curt's Release-Snapshots, which is an unlimited Release-Preview of the next upcoming FGFS-version.
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: Helicopter realism -- or not? Real pilot tests?

Postby ranger8 » Mon Mar 28, 2011 8:44 pm

Thanks, Im getting pretty excited about getting to work on this. cant wait to get home!
ranger8
 
Posts: 15
Joined: Mon Mar 28, 2011 3:11 pm

Re: Helicopter realism -- or not? Real pilot tests?

Postby ranger8 » Tue Mar 29, 2011 1:20 pm

Hey, Groucho and HHS,

I downloaded the program last night and added the R22. My joystick setup is not a typical one, I built it with a board from leo bodnar and confiqured potentiometers to the controls in the salvaged ship. so I have some work to do there, the auto detection didn't recognize my set up. It did create a default that at least gave me both cyclic axis's and collective, but no ani-torque pedals. I have read the manual this morning and think I can over come these issues, hopefully tonight if time permits.

That being said, I am initially impressed with the R22 flight dynamics. Without any tail rotor authority, when collective was added, the nose yawed to the right with much vigor. This is exactly how it should be and impressed me right away over from what I've been experiencing in FSX, but what happened next really sealed it!

After adding enough collective to gain some altitude(spinning to the right the whole time), I decreased collective, wich stops the right yaw, nosed forward to gain a little airspeed, and through manipulation of the collective, was able to reasonably choose or maintain a heading, and fly(pretty much right turns only)

The contol inputs needed were completly accurate to what would be needed in a helicopter which had lost it's tail rotor authority! :D
Now this is what I've been looking for!
ranger8
 
Posts: 15
Joined: Mon Mar 28, 2011 3:11 pm

Re: Helicopter realism -- or not? Real pilot tests?

Postby redneck » Tue Mar 29, 2011 1:27 pm

If you have Windows, you need to rewrite the default joystick, found in C:\Program Files (x86)\FlightGear v20101219\data\Input\Joysticks\Default. Note that your directory may look a little different. Chances are you're running a different version of FG than I am.
Call Signs: redneck, ATCredn (unspecified freq atc)
FGFSCopilot
FGFSCopilotATCEdition
System Specs
Model: Alienware M15x, OS: Windows 7 Professional 64-bit, RAM: 3 GB, CPU: Intel i3 quad core at 2.4 GHz, GPU: Nvidea GeForce GTX 460M 1.5 GB GDDR5
redneck
 
Posts: 3630
Joined: Mon Feb 02, 2009 2:17 am
Location: Pennsylvania, USA
Version: 240

Re: Helicopter realism -- or not? Real pilot tests?

Postby someguy » Tue Mar 29, 2011 1:34 pm

Wait until you try an autorotation drill.

As Heiko said, most of the behavior is there. Some aspects may need to be fine tuned, which really requires feedback from an experienced real-life pilot. Your Brain Will Be Picked. :)
User avatar
someguy
 
Posts: 1653
Joined: Tue Nov 25, 2008 5:54 am
Location: USA
Version: 2016.2.1
OS: Mac OS X 10.11

Re: Helicopter realism -- or not? Real pilot tests?

Postby redneck » Tue Mar 29, 2011 1:41 pm

Oh yeah. I remember back when I used to practice autorotation all the time. But if that was real, I'd be dead :lol: The rotors don't take damage, even at (I think) 150 percent RPMs.
Call Signs: redneck, ATCredn (unspecified freq atc)
FGFSCopilot
FGFSCopilotATCEdition
System Specs
Model: Alienware M15x, OS: Windows 7 Professional 64-bit, RAM: 3 GB, CPU: Intel i3 quad core at 2.4 GHz, GPU: Nvidea GeForce GTX 460M 1.5 GB GDDR5
redneck
 
Posts: 3630
Joined: Mon Feb 02, 2009 2:17 am
Location: Pennsylvania, USA
Version: 240

Re: Helicopter realism -- or not? Real pilot tests?

Postby Groucho » Tue Mar 29, 2011 1:49 pm

ranger8 wrote in Tue Mar 29, 2011 1:20 pm:After adding enough collective to gain some altitude(spinning to the right the whole time), I decreased collective, wich stops the right yaw, nosed forward to gain a little airspeed, and through manipulation of the collective, was able to reasonably choose or maintain a heading, and fly(pretty much right turns only)

The contol inputs needed were completly accurate to what would be needed in a helicopter which had lost it's tail rotor authority! :D
Now this is what I've been looking for!


Well, you have just encountered the reason of the R22´s bad reputation in FlightGear :)
People are having a hard time to control the moped because they have to work hard and rather sensible to compensate exactly that behavior.
Most people in the community try it once and then never and I always had a hard time to convince them that the R22 is pretty realistic in this area 8)
_____________________________________
Callsign: D-HARP
Flight locations: TNCM, TKPK, EDNY, LOWI
Aircrafts
Helis: EC130, Bo105, UH-1, R22
Twins/Jets: Aerostar, CRJ-200
User avatar
Groucho
 
Posts: 1216
Joined: Sun Jun 17, 2007 10:28 am
Location: Airborne Lake Constance/Germany
Callsign: D-HARP
Version: GIT
OS: Kubuntu

PreviousNext

Return to Helicopter

Who is online

Users browsing this forum: No registered users and 1 guest