Re: [Flightgear-devel] FMC / GPSs

[James Turner]

On Sunday, January 26, 2003, at 08:47  pm, Norman Vine wrote:


You are aware of these
http://www.ibiblio.org/fplan/
http://www.ibiblio.org/fplan/avdbtools/guide.html

and FlyWay at
http://www.bellz.org/progs.html


Ah, I'm aware of things like them, but I guess my terminology is wrong. 
What I'm working on is the in-memory representation of routes. 
Obviously I'm expecting to write importers for any formats that exist 
already (eg SquawkBox and FS2k2), as well as the XML one I've knocked 
up. I know there's a Java one for X-Plane which is also popular, again, 
I'm happy to steal people's data formats. If someone wants to write an 
in-process flight planner, they can do that too (hell, I might even get 
around to it myself in a year or so...)

Right now, I'm not really worrying about that, but rather pulling all 
the disparate bits of data (navaids, airports, aero data, position 
info) to make up the working flight-management system. I simply had to 
do the 'flight plan' bit first because that's something that wasn't 
already there (at least, the logic in Simgear/Route and the existing 
simple flight plan format isn't nearly semantically rich enough for my 
purposes).

I am aiming to eventually support the full feature set of Boeing and 
Airbus CDUs, so I need things like 'smart' joining of airway and 
procedure segments into chunks of route, on-the-fly (re-)selection of 
arrival runways and procedures, auto-sequencing of missed-approach 
segments, holding at waypoints (including picking up default hold 
parameters for holds on STARs), and so on (and on...). Hopefully the 
classes I'm doing up are flexible enough to handle all this and more, 
since I certainly don't know all the things every FMC out there can do.

Anyway, I'm calling a sequence of waypoints you *could* fly a 
'flightplan', and a set you *are* flying (i.e once you get clearance, 
pick an aircraft and fuel load, and know your departure runway and 
procedure) an 'active route'. If my terminology is horribly skewed, 
please correct me sooner rather than later :-)

H&H
James
--
We are all in the gutter, but some of us are looking at the stars.


___
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel

Re: [Flightgear-devel] FMC / GPSs [ was End of /steam approaches]

[Norman Vine]

James Turner writes:
> >
> 
> Actually, I'm rapidly approaching that area, from a different 
> direction. I'm working on extending the Navaids layer to know about 
> structured route data, namely DPs / SIDs / STARs / GPS approaches / 
> airways, but most importantly, flight plans. 

You are aware of these 
http://www.ibiblio.org/fplan/
http://www.ibiblio.org/fplan/avdbtools/guide.html

and FlyWay at
http://www.bellz.org/progs.html

Cheers

Norman

___
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel

[Flightgear-devel] FMC / GPSs [ was End of /steam approaches]

[James Turner]

On Sunday, January 26, 2003, at 05:12  pm, Norman Vine wrote:



Hopefully we can now actually start implementing a realistic 
'navigation computer',
as is present in most modern GPS units and autopilots that, since the 
hopefully the
AP is no longer dependent on hardwired to steamed input from C172 
instrumentation



Actually, I'm rapidly approaching that area, from a different 
direction. I'm working on extending the Navaids layer to know about 
structured route data, namely DPs / SIDs / STARs / GPS approaches / 
airways, but most importantly, flight plans. I've got an XML format I'm 
reading in, and am about to start exposing the data to the property 
system.

One of my 'route' types is FGActiveFlightPlan, which is designed to 
provide a good chunk of the runtime state necessary to drive either a 
KLN-89b-style thing, or a full blown FMC (c'mon Dave Culp, I need that 
737!).  What I'm hoping is that with our new-found scripting 
capability, a lot of the 'device specific' logic I was probably going 
to do in code can be done in scripts in the instrument files, providing 
my C++ code exposes rich enough data to the property system (shouldn't 
be a problem).

BTW, there is another important goal of my flightplan code that it 
should be common to multiple subsystems. most notably that AI aircraft 
and full-blown ATC systems should be able to work from the same base 
classes. FMCs and such are my initial goal, though.

Current plan of attack is :
- get the flight plans exposed into the property system. Will look 
something like

/ .. owner system /flightplan[n]/origin/icao = EGPH
/ .. owner system /flightplan[n]/origin/runway = 06
/ .. owner system /flightplan[n]/destination/icao = EDDF
/ .. owner system /flightplan[n]/desintation/runway = 27L
/ .. owner system /flightplan[n]/eta = .. computed time
/ .. owner system /flightplan[n]/waypoints[0]/id = TLA
/ .. owner system /flightplan[n]/waypoints[0]/alt = 8000  (this is a 
crossing restriction)
/ .. owner system /flightplan[n]/waypoints[1]/id = DCS
/ .. owner system /flightplan[n]/waypoints[2]/id = ... etc

(all subject to change!)
The owner system might be an FMC / GPS unit, an /aircraft[n]/ai node 
for an AI plane,
an /atc/aircraft/ node, or so on.

- one the above is done (hopefully in the next few days), I'm going to 
hook up the waypoint following in the current autopilot to follow my 
loaded flight-plans. Once that's done I need to try adding route 
sub-structures, i.e airways (easy) but then also the different kinds of 
DPs, STARs and GPS / non-precision approaches. My intention is to write 
loaders that parse some of the existing formats out there, so we leech 
the data available for the various FS2000/2 flight computer devices.

Anyway, that's about where I am, none of this stuff is in CVS yet, if 
anyone else thinks they're working in an area where they might benefit 
from this, let me know and I'll see about getting it committed. 
Otherwise I'll keep the damage confined locally, the API, such as it 
is, is changing daily at the moment!

H&H
James

--
Morbo finds all humans pathetic


___
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel