headers
David Culp | 15 Oct 2003 16:05
Picon

Fwd: [Jsbsim-devel] new SimTurbine config spec


I've changed the config spec for the SimTurbine module slightly.  The changes
are:

1)  The old MAXMILTHRUST is now called MILTHRUST

2)  added MAXTHRUST

3)  table(2) now provides multipliers to the MAXTHRUST value.

The MAXTHRUST value is the afterburning thrust, static at sea level
(installed).  This is the value commonly found in Janes and similar sources.
(Actually, that value probably comes straight from the engine manufacturer's
marketing department, so it's probably a test-bed value at ideal conditions,
but without any proof of deception we'll have to go with it.  You may want to
knock off a few percent for accessory load, non-optimum inlet and age)

The table(2), "AugThrust", below is data from the EngineSim java applet at
http://www.grc.nasa.gov/WWW/K-12/airplane/ngnsim.html
for the F-100 engine.  The variation of thrust with mach and altitude should
be about the same for other afterburning engines, so the table can be
re-used.  Now you can model a different afterburning engine without having to
redo the whole table.

Below is the new J85 config file.

*****************************************************************************
******** <?xml version="1.0"?>

<!-- J85-GE-5 afterburning turbojet engine model
(Continue reading)

Permalink | Reply | 0 comments |
headers
Lee Elliott | 16 Oct 2003 21:37
Picon
Picon

Flight control sensitivity

Hello all,

I've been re-working the TSR2 (YASim) and while most of it's gone ok I've 
run into a bit of a problem.

Because the TSR2 has no ailerons, roll being controlled by differential 
use of the elevators, I've bound the aileron control input to the 
elevators, as well as the normal elevator control input.

This works in so far as the elevators respond to both the elevator and 
aileron control inputs but the problem is that the aileron input is too 
severe.  I can control this under AP control by limiting the max aileron 
deflection, which seems to work ok but I can only achieve adequate 
control via the joystick by setting the joystick aileron axis factor to 
0.2 instead of the normal 1.0.

I've not been able to effect this change by re-setting the axis factor in 
the 'set' file but it does work if I specify it on the command line i.e. 
by adding --prop:/input/joysticks/js[0]/axis[0]/binding/factor=0.2 to the 
parameters.

I really don't want to have to fiddle the a/c even more than my guesswork 
has already done, and split the flap span into a flap + aileron but this 
means I need some way of adjusting the aileron control axis factor either 
in the fdm or via the property tree.  Expecting people to add the extra 
parameter isn't really on and the actual axis to change might vary 
between different joysticks, adding to user confusion.

Help!
(Continue reading)

Permalink | Reply | 3 comments |
headers
Andy Ross | 17 Oct 2003 01:15
Gravatar

Re: Flight control sensitivity

Lee Elliott wrote:
 > This works in so far as the elevators respond to both the elevator
 > and aileron control inputs but the problem is that the aileron input
 > is too severe

YASim allows you to bind a property to a control with a configurable
range.  The default for aileron control is, of course, full deflection
(that is a joystick property swing of -1:1 corresponds to the full
range of the elevons), but it doesn't have to be that way.  You can
use the src/dst parameters in the control-input tag.

I might be getting the syntax a bit wrong the top of my head, but you
are basically given a pair of src0/src1 attributes to control the
input (property tree/joystick value) side of the transformation and
dst0/dst1 attributes to define the mapping into the YASim elevon
deflection.  So if you want to map full joystick deflection to only
10% of the range, you'd do something like:

  <control-input ... src0='-1' src1='1' dst0='-0.1' dst1='0.1' ...>

Does that make sense?

Andy
Permalink | Reply | 2 comments |
headers
Lee Elliott | 17 Oct 2003 02:15
Picon
Picon

Re: Flight control sensitivity

On Friday 17 October 2003 00:15, Andy Ross wrote:
> Lee Elliott wrote:
>  > This works in so far as the elevators respond to both the elevator
>  > and aileron control inputs but the problem is that the aileron input
>  > is too severe
> 
> YASim allows you to bind a property to a control with a configurable
> range.  The default for aileron control is, of course, full deflection
> (that is a joystick property swing of -1:1 corresponds to the full
> range of the elevons), but it doesn't have to be that way.  You can
> use the src/dst parameters in the control-input tag.
> 
> I might be getting the syntax a bit wrong the top of my head, but you
> are basically given a pair of src0/src1 attributes to control the
> input (property tree/joystick value) side of the transformation and
> dst0/dst1 attributes to define the mapping into the YASim elevon
> deflection.  So if you want to map full joystick deflection to only
> 10% of the range, you'd do something like:
> 
>   <control-input ... src0='-1' src1='1' dst0='-0.1' dst1='0.1' ...>
> 
> Does that make sense?
> 
> Andy

Hello Andy,

I think that's exactly what I want - thanks:)  I think I might be able to 
use it on the yf23 too, where I use the rudder input on the stabilators 
and ailerons but haven't been able to balance them very well.
(Continue reading)

Permalink | Reply | 0 comments |
headers
Lee Elliott | 17 Oct 2003 03:02
Picon
Picon

Re: Flight control sensitivity

On Friday 17 October 2003 00:15, Andy Ross wrote:
> Lee Elliott wrote:
>  > This works in so far as the elevators respond to both the elevator
>  > and aileron control inputs but the problem is that the aileron input
>  > is too severe
> 
> YASim allows you to bind a property to a control with a configurable
> range.  The default for aileron control is, of course, full deflection
> (that is a joystick property swing of -1:1 corresponds to the full
> range of the elevons), but it doesn't have to be that way.  You can
> use the src/dst parameters in the control-input tag.
> 
> I might be getting the syntax a bit wrong the top of my head, but you
> are basically given a pair of src0/src1 attributes to control the
> input (property tree/joystick value) side of the transformation and
> dst0/dst1 attributes to define the mapping into the YASim elevon
> deflection.  So if you want to map full joystick deflection to only
> 10% of the range, you'd do something like:
> 
>   <control-input ... src0='-1' src1='1' dst0='-0.1' dst1='0.1' ...>
> 
> Does that make sense?
> 
> Andy

Just tried it - worked a treat:)  Used double quotes, as per FG norm, 
instead of single quotes.

LeeE
(Continue reading)

Permalink | Reply | 0 comments |
headers
Jon Berndt | 24 Oct 2003 14:13
Picon

JSBSim web page

I've got some redesign work to do on the JSBSim main page - it's getting too
wide. :-)

Welcome David Culp to the front page.

Jon
Permalink | Reply | 0 comments |
headers
David Culp | 28 Oct 2003 20:01
Picon

AI tanker

I've got an AI tanker running, based on David Luff's AIPlane class.  It comes 
with it's own simple FDM, and is configurable to a degree through 
preferences.xml.  Initially it was tied to a non-GPL KC-135 model, but now it 
can use any model from the base package, like the A320:

http://home.comcast.net/~davidculp2/tanker3.jpg

I'll send the code to whomever's interested, and if someone would like to add 
it to FlightGear CVS eventually, that would be nice too :)

This also brings up the possibility of generalizing the existing AI code a 
bit.  The AITanker is tied to KEMT because it's managed by AIMgr, but there 
is no reason it couldn't be applied to any location with some minor code 
changes.

Dave
--

-- 
****************************
David Culp
davidculp2[at]comcast.net
****************************
Permalink | Reply | 3 comments |
headers
David Culp | 30 Oct 2003 17:37
Picon

Re: AI tanker

Anyone interested in an IA tanker or IA other?

Bueller?

Dave
--

-- 
****************************
David Culp
davidculp2[at]comcast.net
****************************
Permalink | Reply | 2 comments |
headers
Lee Elliott | 30 Oct 2003 20:21
Picon
Picon

Re: AI tanker

On Thursday 30 October 2003 16:37, David Culp wrote:
> Anyone interested in an IA tanker or IA other?
> 
> Bueller?
> 
> 
> Dave
> -- 
> ****************************
> David Culp
> davidculp2[at]comcast.net
> ****************************

I'm certainly interested but I'm a bit busy atm.

LeeE
Permalink | Reply | 1 comment |
headers
Erik Hofman | 30 Oct 2003 21:20

Re: AI tanker

Lee Elliott wrote:
> On Thursday 30 October 2003 16:37, David Culp wrote:
> 
>>Anyone interested in an IA tanker or IA other?
>>
>>Bueller?
>
> I'm certainly interested but I'm a bit busy atm.

The code is always welcome. We could generalize it a bit more later on.

Erik
Permalink | Reply | 0 comments |

Gmane