Board index FlightGear Development Aircraft

DG-101G glider, version 20130107

Questions and discussion about creating aircraft. Flight dynamics, 3d models, cockpits, systems, animation, textures.

DG-101G glider, version 20130107

Postby nike » Sat May 02, 2009 2:52 pm

Hello,

I'm working for a while on a glider. It's a DG-101G. This is a standard class glider, that flew first in 1974. It was the first plane from Glaser-Dirks, Germany.

Image
This is the initial liverie.

Image
A look from the pilot's view to the instruments.

Image
The plane with the drag robot on the runway.

Features:
  • The flight dynamics model uses JSBSIM. Initially it was created with the Aeromatic tool on the JSBSIM homepage. But to increase accuracy most properties has been re-calculated with XFLR5. Only a few properties are used from Aeromatic, as XFLR5 is not capable to calculate them.
  • This model allows for winch start. The winch is highly configurable via gui: tow length, tow speed, pull force, bracking force, force reduction dependent to speed and angle. It will be placed in front of the glider. If there is allready a winch created, no further winch can be created.
  • Aerotowing is possible with Multiplayer as well as with AI-planes. The dragger can be selected via gui. Also the tow characteristics are configurable.
  • As a unique feature this model has a drag roboter, that allows for aerotowing on any airport. So, to use aerotowing it is no longer necessary for multiplayer supported dragger, nor is it necessary to use the AI scenario KRHV_towing_demo. The code also considers effects by moving air-masses. It is also possible to modify certain characteristics of the drag robot like acceleration, exit height and so on.
  • Instrumentation: most instruments are based on types from Winter, a german aviation instruments company. The 80mm VSI is a TE compensated type, whereas the 57mm type is un-compensated. The McCready ring is based on the calculated polar. The radio is based on the FSG2T from Dittel. The AI has a height ring. All instruments are manageable with the mouse. The turn indicator and the yaw-string has been updated with this release.
  • This plane enables water ballast. The tanks can be filled whenever you want (what is not really reasonable, because in air it is not really reasonable - maybe I will change the code in the future).
  • The glider has now an extended configuration menu, that allows glider settings, winch configuration and operation, drag roboter configuration and operation, aerotowing configuration and operation. The gui is designed to access basic properties directly. Advanced properties are accessible via sub-dialogs.

New features:
  • improved animation of rope and parachute for winch launch
  • initial Rembrandt implementation

Open points:
  • The drag roboter does not take into acount the terrain surrounding the airport. So, if there are high hills very close the the runway it can happen that the dragger fly through the terrain (not really realistic).
  • Loading water ballast should be possible only on ground.
  • Many other things, I have not in mind right now ...


For a full description of all functionality take a look at the wiki page. That page will be updated as soon as possible after publishing new releases.

Compatibility: works with FG v2.0, v2.4 and v2.6

The latest release:
2013-01-07: Can be found in GIThttp://mapserver.flightgear.org/git/?p=fgdata;a=tree;f=Aircraft/DG-101G;hb=HEAD
On the middle pane use snapshot to get the package.

Older releases:
In case somebody is interested on older releases (before initial commit to GIT) feel free to contact me.

nike
Last edited by nike on Tue Jan 08, 2013 6:55 pm, edited 24 times in total.
nike
 
Posts: 51
Joined: Sat May 02, 2009 2:25 pm

Re: DG-101G glider

Postby airforce master » Sat May 02, 2009 5:20 pm

nice
Last edited by airforce master on Sat May 02, 2009 6:02 pm, edited 1 time in total.
airforce out
airforce master
 
Posts: 158
Joined: Sat Apr 12, 2008 11:14 pm
Location: In the Sky

Re: DG-101G glider

Postby HHS » Sat May 02, 2009 5:20 pm

Hi,

Nice aircraft! Go on, this is really nice!
The only improvment left in the moment is to smooth the 3d-model. "set smooth" will make it look perfect! And set "ambient color" to 1, so you don't have a dark glider.
For the fdm: if windtunnel/ airfoil datas available then it is JSBSim a good start. The only thing is, you can't be towed yet by an another aircraft like MP, or AI.
YASIM gives the ability to beeing towed by another aircraft, MP or AI maybe you are pilot of the real thing, so you should be able to make it realistic as it can be! :D

Nice addition to he new ridge lift in FGFS!
Regards
HHS
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: DG-101G glider

Postby HHS » Sat May 02, 2009 5:21 pm

airforce master wrote:I'm sorry but if DG stands for DeltaGlider then you can not use it


?????

DG = Dirk Glaser - the name of the aircraft manufactor: http://www.dg-flugzeugbau.de/index-e.html
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: DG-101G glider

Postby gooneybird » Sat May 02, 2009 6:02 pm

I'll echo the comments from HHS, It would also be nicer if you could use the same keys as the other gliders for winch and speed brakes etc. just to keep everything uniform.

A nice addition to the glider collection. :D
gooneybird
 
Posts: 2971
Joined: Sat May 31, 2008 1:57 pm

Re: DG-101G glider

Postby grtux » Sat May 02, 2009 10:24 pm

HHS wrote:Hi,

Nice aircraft! Go on, this is really nice!
The only improvment left in the moment is to smooth the 3d-model. "set smooth" will make it look perfect! And set "ambient color" to 1, so you don't have a dark glider.
For the fdm: if windtunnel/ airfoil datas available then it is JSBSim a good start. The only thing is, you can't be towed yet by an another aircraft like MP, or AI.
YASIM gives the ability to beeing towed by another aircraft, MP or AI maybe you are pilot of the real thing, so you should be able to make it realistic as it can be! :D

Nice addition to he new ridge lift in FGFS!
Regards
HHS


Towing with JSBSim won't be that difficult, remember the <external_reaction> is a flexible (very flexible) process , which can offer that feature.
I have some idea on how to do it ( part of my Halifax project with transportation troop Glider)
You only need some additional Nasal script with Geo.
Then anybody who wish to do towing can do it with JSBsim, over MP.
Yes We Can :)
Cheers
g.robin
LFMO
User avatar
grtux
 
Posts: 432
Joined: Thu Dec 14, 2006 4:19 pm
Location: Provence France

Re: DG-101G glider

Postby nike » Wed May 20, 2009 8:13 am

First of all: Thank you for the comments.

To answer to your comments regarding:
    model quality (textures, smoothing the surfaces, ... )
    I know, the model is not perfect. I will work on that topic in the next release, but it will not be the main focus of my work at the moment. I can't see the mentioned problem with a dark model. So if someone could send me a screenshot to show this failure that would be helpful for me to understand that point.
    keys
    I can change the keys to the same functions as the other gliders have. When I started with my plane, I have checked the already used keys. And the keys for handling a winch are already in use with other functions. The "w"-key for example is used to increase warp, but the glieders use it to start the winch. The "W"-key is used to decrease warp, but the glieders use it to release the winch. My question at this point is: what happens with a key assigned to a different function? Is the original assignment lost? Or does the key work on both functions? If this double usage of certain keys is not a problem, I can also change the keys of my glider.

What are the next topics I want to work on:
    Thermals
    The next release will have a function to place thermals in a certain area around the plane, no matter at what airport you start. The function will use the thermals from the AI-scenario "thermal-demo.xml" or other thermals it finds in the property tree. The distribution around the plane is quite simple, so it doesn't take care for real situations as the depend on weather, terrain and so on. But it will place thermals where ever you fly. (topic nearly finished)
    Aerotowing
    This will be the main focus for the next step. The idea is to use the "KRHV_towing_demo.xml" and mangle it by a function to use it at any airport, not only at KRHV. But to do so I have to understand first how this scenario works, especially with the flightplan and how to manipulate it to an other airport without creating a special flightplan in the AI-folder.

regards
nike
nike
 
Posts: 51
Joined: Sat May 02, 2009 2:25 pm

Re: DG-101G glider

Postby HHS » Sat May 23, 2009 6:44 pm

Hi,

.... I can't see the mentioned problem with a dark model. So if someone could send me a screenshot to show this failure that would be helpful for me to understand that point.

So you are using 1.9.1, not cvs. The next release of FGFS (maybe end of this year) FGFS now uses the ambient color settings of the .ac-model. In Blender the default setting is 0.5 0.5 0.5 so the aircraft appear very dark, nearly black. To change this, you can change it with a text editor: open the .ac-model in the editor and change the lines regarding the materials from
Code: Select all
MATERIAL "Fuselage" rgb 1 1 1 [B]amb 0.5 0.5 0.5 [/B]emis 1 1 1 spec 0 0 0 shi 64 trans 0

to
Code: Select all
MATERIAL "Fuselage" rgb 1 1 1 [B]amb1 1 1 [/B]emis 1 1 1 spec 0 0 0 shi 64 trans 0
.

This change isn't noticable on 1.9.1 but in CVS and the next releases of FGFS!


keys
....The "w"-key for example is used to increase warp, but the glieders use it to start the winch. The "W"-key is used to decrease warp, but the glieders use it to release the winch. My question at this point is: what happens with a key assigned to a different function? Is the original assignment lost? Or does the key work on both functions? If this double usage of certain keys is not a problem, I can also change the keys of my glider.


ASK 21(Mi), Bocian used this from the beginning of this winch feature, so it would be very recommended to do it also. Indeed the time warp isn't working on the gliders, but it is needed? It is nearly impossible to use another key, as everyone is used somewhere for something. But I can remember of a multikey implementation- somewhere in CVS. Maybe this could help.


What are the next topics I want to work on:
    Thermals
    The next release will have a function to place thermals in a certain area around the plane, no matter at what airport you start. The function will use the thermals from the AI-scenario "thermal-demo.xml" or other thermals it finds in the property tree. The distribution around the plane is quite simple, so it doesn't take care for real situations as the depend on weather, terrain and so on. But it will place thermals where ever you fly. (topic nearly finished)


Sounds nice, but not realistic. ( but something every glider pilot dreams )I would like to see thermals undependant of the aircraft and depending of locations, weather and sun. But that's hard to make. So your idea sounds quite nice!

    Aerotowing
    This will be the main focus for the next step. The idea is to use the "KRHV_towing_demo.xml" and mangle it by a function to use it at any airport, not only at KRHV. But to do so I have to understand first how this scenario works, especially with the flightplan and how to manipulate it to an other airport without creating a special flightplan in the AI-folder.


Maybe a look into the tanker.nas in CVS could help.
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: DG-101G glider

Postby gooneybird » Sat May 23, 2009 8:39 pm

I've been playing around with AI aircraft for aerotowing, but even with the new traffic speed manager in CVS they are still going to fast, you can just hang on to them with the ASK 21 but it's an unrealistic flight.
The reason I'm trying AI traffic and not the towing scenario is for the portability, At the moment I have a c172 leaving LOWI every 10 minutes. To move this to another airport would only take a few minutes to alter the departure and arrival ports in the xml file, as opposed having to rewrite all the coordinates in a towing scenario.
When the AI speed is fixed I believed this would be the easiest way to handle AI aerotowing for different airports.
gooneybird
 
Posts: 2971
Joined: Sat May 31, 2008 1:57 pm

Re: DG-101G glider

Postby nike » Fri May 29, 2009 12:08 pm

One question regarding new properties:
For the winch (and in future for the towing) I need new properties in the proterty tree. Currently I have placed the new proterties for the winch in the root of the tree. I guess this is the wrong place. Where in the tree is a good place?

nike
nike
 
Posts: 51
Joined: Sat May 02, 2009 2:25 pm

Re: DG-101G glider

Postby nike » Wed Jun 17, 2009 2:35 pm

Update of DG-101G

Here is my update of the DG-101G glider:
http://www.ski-svw.de/nike/DG-101G_20090616.zip

Modifications:
  • Aerotowing:
    A basic functionality for aerotowing is integrated. Pressing "Ctrl-o" searches for a plane in a circle of max. 60m around the current position and a callsign of "dragger". Pressing "o" attaches to this plane and pressing "O" releases from this plane.
  • Thermals:
    The configuration file of the glider loads automatically the "thermal-demo" scenery, no matter where your starting airport is. Pressing "t" checks for distance of thermals to current glider position and update the locations for those thermals, that are more than 15km away. The repositioned thermals are arranged in 6 segments of a circle around the glider. There is no logic behind the distribution of the thermals considering terrain or other things, the only logic is to place them randomly in a circle around the glider. But it allows to use thermals at any location without generating a special scenery.
  • Keys:
    Due to the feedback from others I have changed the keys to the same functions as in Bocian and ASK21. Winch is handled by "Ctrl-w", "w" and "W". Aerotowing is handled by "Ctrl-o", "o" and "O".
  • 3d-model:
    A few details have been smoothed (e.g. wings, the stick and pedals). Also I have introduced a first approach of texture for the fuselage.

Plans for further development:
  • Aerodynamics:
    A real glider pilot with experience with this type of glider told me that this model is less agile than the real plane. Also the crash behavior is not realistic. So my next effort will be to work on aerodynamics and tune it to more realistic behavior.
  • 3d-model:
    Also the textures need a lot of tuning. Maybe some liveries could be integrated in the next update. (Artists are welcome to supply textures)
  • Functionality:
    At the moment the basic functionality of winch and aerotowing is ok for me. Further improvement will be done, but with low priority.


Please send me feedback about this update. What is good, what is not so good, what are your wishes for this glider?

regards
nike
Last edited by nike on Wed Jun 24, 2009 1:59 pm, edited 1 time in total.
nike
 
Posts: 51
Joined: Sat May 02, 2009 2:25 pm

Re: DG-101G glider

Postby HHS » Thu Jun 18, 2009 4:52 pm

Sounds awsome- I'll take a look!
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Re: DG-101G glider

Postby f-ojac » Sat Jun 20, 2009 9:16 am

Hi,

Do you plan to upload/have this this nice model uploaded to CVS ?
--
If you want to support my Terrasync server, hosted on a private server, you can donate here: http://ns334561.ip-5-196-65.eu/WS2.0/WS ... 2.0.1.html
f-ojac
 
Posts: 1276
Joined: Fri Mar 07, 2008 9:50 am
Version: GIT
OS: GNU/Linux

Re: DG-101G glider

Postby nike » Wed Jun 24, 2009 1:57 pm

Hello Olivier,

to have this model in CVS would be nice. As I have no access to CVS someone has to do it for me. Or someone explains me how to get access to CVS.

Before uploading I would like to have a certain maturity level of the model. In my opinion this level is not reached for the moment. There are to many unfinished points (e.g. naming of instruments/components, functionality, aerodynamic configuration, liveries). So I would like to improve the model before uploading (whether by myself or someone other) to CVS.

regards
nike
nike
 
Posts: 51
Joined: Sat May 02, 2009 2:25 pm

Re: DG-101G glider

Postby HHS » Wed Jun 24, 2009 2:58 pm

nike wrote:Hello Olivier,

to have this model in CVS would be nice. As I have no access to CVS someone has to do it for me. Or someone explains me how to get access to CVS.


Unfortunately a aicraft developer doesn't get a CVS-access easily. But we have a lot of developers with CVS-access even here in the forum: helijah, Detlef, Stuart....
More you will find on the IRC-chat or on the devel-list. Just a mail, note etc. and will be uploaded to CVS.

Before uploading I would like to have a certain maturity level of the model. In my opinion this level is not reached for the moment. There are to many unfinished points (e.g. naming of instruments/components, functionality, aerodynamic configuration, liveries). So I would like to improve the model before uploading (whether by myself or someone other) to CVS.

regards
nike


Release early, release often!
You have enabled features which were wished a long time for JSBSim-aircrafts! That's why it would be really worth to have this already in CVS! CVS is the place for unfinished aircrafts.

Regards
HHS
Up, up and away
User avatar
HHS
Retired
 
Posts: 3624
Joined: Thu Jul 19, 2007 8:09 am
Version: GIT

Next

Return to Aircraft

Who is online

Users browsing this forum: No registered users and 3 guests