RE: [Flightgear-devel] ANN: Fuel
- check whether JSBSim is actually applying the weight for the fuel I believe we are. I'd be surprised if we are not. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
Jon S. Berndt writes: - check whether JSBSim is actually applying the weight for the fuel Yes, we are. Look at FGMassBalance.cpp: That's good news. Once you start applying pointmass as well, I can tie it into the property manager and we can set up loads in the plane properly. Yesterday, I tried the FLY! C172R with a full left-wing fuel tank, an empty right-wing fuel tank, and one passenger sitting directly behind the pilot on the left side of the plane. It was an interesting experiment -- I almost lost rudder authority during the initial climb. All the best, David -- David Megginson [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
David Megginson writes: If you grab the latest SimGear, FlightGear, and base package from CVS, you'll notice that fuel consumption is now working on JSBSim piston-engine aircraft (well, the Cessna 310 doesn't have the right number of tanks or the right fuel capacity, and the Cessna 182 has a 172 gauge that goes only as high as 28 gal_us/tank, but I'm working on it). No more non-stop, transpacific flights on autopilot. COOL , Great :-) But we need an overide to ignore fuel consumption so we can do non-stop around the world flights on autopilot. I keep thinking of an old post by Oliver where he couldn't get to his machine because the neighborhood kids were using it to fly FlightGear all the time. They loved it because it was a SIMPLE FlightSim. ie the engines were already started you didn't have to worry about running out of fuel when you crashed you just used the reset menu when a mountain got in the way you just added emergency altitude when you wanted to go faster you hit the accelerator key ect.. This was a while ago and the SIM is much more 'realistic' now but I wonder if it would still have the same appeal as it did to those kids a couple of years ago or if they would consider it another of those 'adult sims' that was too complicated ? IMHO the realism is great but we should also keep the KISS version around. BTW - Nice addition, we needed this :-) Cheers Norman ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
Norman Vine writes: David Megginson writes: If you grab the latest SimGear, FlightGear, and base package from CVS, you'll notice that fuel consumption is now working on JSBSim piston-engine aircraft (well, the Cessna 310 doesn't have the right number of tanks or the right fuel capacity, and the Cessna 182 has a 172 gauge that goes only as high as 28 gal_us/tank, but I'm working on it). No more non-stop, transpacific flights on autopilot. COOL , Great :-) But we need an overide to ignore fuel consumption so we can do non-stop around the world flights on autopilot. What is done on the big commercial sims is to have a fuel-freeze option. With this enabled, everything else happens normally, except no fuel is subtracted from the tanks. This is useful for training as well because sometimes you want to eliminate changing weight and balance issues when you are concentrating on practicing/learning something else. I think it would be useful to have: master-freeze - the entire sim pauses fuel-freeze - tank quantities don't change position-freeze - lat/lon doesn't change (but if everything else behaves normally.) This gives you the option of practicing various maneuvers without leaving a training area ... more important if you are buying time in a real 747 sim, but still would be useful for us. time-of-day-freeze - sun/moon/stars/lighting doesn't change/progress. Anything else? Regards, Curt. -- Curtis Olson Intelligent Vehicles Lab FlightGear Project Twin Cities[EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
Norman Vine writes: But we need an overide to ignore fuel consumption so we can do non-stop around the world flights on autopilot. Hmm -- maybe you could set up a Python script to refill the tanks every few hours. Note that the FGRocket engine model used by the X-15 was already consuming fuel -- proper fuel consumption just hadn't been implemented for FGPiston yet. I keep thinking of an old post by Oliver where he couldn't get to his machine because the neighborhood kids were using it to fly FlightGear all the time. They loved it because it was a SIMPLE FlightSim. ie the engines were already started you didn't have to worry about running out of fuel Practically speaking, you still don't, at least not from the kids' perspective. Even at fairly high high speed, the C172 can stay in the air for 4 hours or more without refueling. When I let kids try flight simulators on my computer, the average flight is about 45 seconds. This was a while ago and the SIM is much more 'realistic' now but I wonder if it would still have the same appeal as it did to those kids a couple of years ago or if they would consider it another of those 'adult sims' that was too complicated ? The biggest problem will be p-factor -- it's very hard to keep the nose straight now on takeoff. In my experience, though, most kids prefer to start in the air anyway. In fact, they might prefer magic-carpet/slew mode over anything else. BTW - Nice addition, we needed this :-) Thanks. All the best, David -- David Megginson [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ANN: Fuel
I haven't still synced everything so I haven't tested this new feature, but for the sake of realness, we can perform a flight around doing scales at airports, and then refill the tanks. If I remember correctly, some properties can be setted in the menu, so we can refuel the plane at any time. On 2002.01.19 15:25 Norman Vine wrote: David Megginson writes: If you grab the latest SimGear, FlightGear, and base package from CVS, you'll notice that fuel consumption is now working on JSBSim piston-engine aircraft (well, the Cessna 310 doesn't have the right number of tanks or the right fuel capacity, and the Cessna 182 has a 172 gauge that goes only as high as 28 gal_us/tank, but I'm working on it). No more non-stop, transpacific flights on autopilot. COOL , Great :-) But we need an overide to ignore fuel consumption so we can do non-stop around the world flights on autopilot. I keep thinking of an old post by Oliver where he couldn't get to his machine because the neighborhood kids were using it to fly FlightGear all the time. They loved it because it was a SIMPLE FlightSim. ie the engines were already started you didn't have to worry about running out of fuel when you crashed you just used the reset menu when a mountain got in the way you just added emergency altitude when you wanted to go faster you hit the accelerator key ect.. This was a while ago and the SIM is much more 'realistic' now but I wonder if it would still have the same appeal as it did to those kids a couple of years ago or if they would consider it another of those 'adult sims' that was too complicated ? IMHO the realism is great but we should also keep the KISS version around. BTW - Nice addition, we needed this :-) Cheers Norman ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
Martin Olveyra writes:
I haven't still synced everything so I haven't tested this new feature,
but for the sake of realness, we can perform a flight around doing scales
at airports, and then refill the tanks. If I remember correctly, some
properties can be setted in the menu, so we can refuel the
plane at any time.
Yes you can but that isn't my point
This is a SIM not a REALITY therefore we can do things differently
then reality and one of those things that should be done differently
IMHO is to have the possibility of a constant fuel supply hence weight !
Note Curt pointed out a few other things that are also normally capable
of 'altering reality' in commercial SIMS.
Don't take me wrong I am all for getting FGFS as REAL as possible
but this shoudn't be done at the expense of keeping the SIM a general
purpose framework that is suitable for all kinds of experiment
I don't see the problem here its just one
if ( ) { ... }
versus having to have either
1) a daemon program or
2) some form of operator interaction
One practical application where it would be useful to have a 'constant'
'known' amount of fuel would be accident reconstruction where one
knew the amount of fuel on board when a crash occured but weren't
sure of what caused it and you kept trying different manuvers testing
the planes responses. If the fuel supply wasn't capable of remaining
constant then the flight characteristics would change as the experiment
progressed.
Cheers
Norman
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RE: [Flightgear-devel] ANN: Fuel
Norman Vine writes: 'known' amount of fuel would be accident reconstruction where one knew the amount of fuel on board when a crash occured but weren't sure of what caused it and you kept trying different manuvers testing the planes responses. If the fuel supply wasn't capable of remaining constant then the flight characteristics would change as the experiment progressed. A common technique in training is to concentrate on one aspect of the task in order to master it before you put all the pieces together. From my 'forced' piano lesson days, I'd often practice the notes for just one hand or the other. It's much easier to put it all together once you have mastered the individual components. On some aircraft, fuel amount, weight and balance is a significant thing and can be a significant distraction when trying to learn something else, so it is very useful from a purely flight simulation point of view to be able to freeze the amount of fuel in the tanks, but have everytyhing else operate normally. Beyond that, the flightgear framework and C172 can be used for many other purposes. I like the idea of having things behave realistically by default, but be able to override some of these realism features as needed. Regards, Curt. -- Curtis Olson Intelligent Vehicles Lab FlightGear Project Twin Cities[EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
Curtis L. Olson writes: Beyond that, the flightgear framework and C172 can be used for many other purposes. I like the idea of having things behave realistically by default, but be able to override some of these realism features as needed. I have no objection to adding special behaviour later, when we've hit some of the higher priorities like weather, GPS, better autopilot, object placement in scenery, better polygon clipping and triangulation in TerraGear, turbine-engine model, air-traffic control, ai-controlled planes, etc. etc.; I'd hate to have to worry about little details right now, though. All the best, David -- David Megginson [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ANN: Fuel
From: Norman Vine [EMAIL PROTECTED] Martin Olveyra writes: I haven't still synced everything so I haven't tested this new feature, but for the sake of realness, we can perform a flight around doing scales at airports, and then refill the tanks. If I remember correctly, some properties can be setted in the menu, so we can refuel the plane at any time. Yes you can but that isn't my point This is a SIM not a REALITY therefore we can do things differently then reality and one of those things that should be done differently IMHO is to have the possibility of a constant fuel supply hence weight ! I agree with both Martin and Norman. I think we should have the ability to freeze variables as Curt already says but we should also have the ability to refuel the plane, on the ground, or during flight for military aircrafts. -Fred ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ANN: Fuel
Why? When you fill up the tanks at the airfield, does the pump count in pounds? I think a better solution would be to leave it as a volume measurement and setup a fuel weight-per-gallon value in the FDM. Having to set the fuel amount as a weight value seems non-intuitive to me. For light aircraft, the pumps measure gallons in the US. For larger aircraft and for which the fuel tanks have relatively little control of fuel temperature (and thus density), the fuel on board is measured in pounds. I don't know what the pump vehicles measure when depositing jet fuel. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ANN: Fuel
On Saturday 19 January 2002 12:41 pm, you wrote: If you grab the latest SimGear, FlightGear, and base package from CVS, you'll notice that fuel consumption is now working on JSBSim piston-engine aircraft (well, the Cessna 310 doesn't have the right number of tanks or the right fuel capacity, and the Cessna 182 has a 172 gauge that goes only as high as 28 gal_us/tank, but I'm working on it). No more non-stop, transpacific flights on autopilot. Currently, fuel is referenced in the property manager by gallons, but I plan on changing it to pounds when I have a chance. Here is a command-line for a short flight where you don't want to carry around over 300lb of fuel in the C172, and thus put only 10 gal_us (about 66 lb) in each tank: fgfs --aircraft=c172 \ --prop:/consumables/fuel/tank[0]/level-gal_us=10 \ --prop:/consumables/fuel/tank[1]/level-gal_us=10 You can read the fuel-flow gauge to see how many gallons your plane is currently using per hour. When both tanks are empty, the engine will stop (I'll add a splutter effect some day), so don't let that happen -- 20 gal_us should still be good for over two hours' flying. By default, neither the C172 nor the C182 starts with a full tank. Coming changes: - use lb rather than gal_us for fuel levels - add the ability to select feed tanks for each engine - check whether JSBSim is actually applying the weight for the fuel - modify JSBSim to clamp fuel levels at tank capacity, to discourage accidental cheating - bug someone until they make new, higher-capacity fuel gauges for the C182 and C310 eheh.. I was thinking, maybe we should make another tree for fig files. It would make things easier because we could reuse stuff and regenerate new textures easier (so I could get better results laying out new textures). You'll note the dual EGT has no numbers. My original version had numbers based on an actual gauge but they were hundreds of degrees too high. No problem, make a copy of th .fig, remove the numbers, viola. I'd like to move to 1 face per texture on some stuff. It would be nice to have 128 and 256px versions. TTYL John ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ANN: Fuel
Cameron Moore writes: - use lb rather than gal_us for fuel levels Why? When you fill up the tanks at the airfield, does the pump count in pounds? As I understand it, larger aircraft do work in pounds. I think a better solution would be to leave it as a volume measurement and setup a fuel weight-per-gallon value in the FDM. Having to set the fuel amount as a weight value seems non-intuitive to me. You'll still be able to work in gallons at the user level, but I'm uncomfortable about using it in the property list -- people on the FDM list have pointed out that it's the weight, not the volume that matters for the engine and the fight model. In any case the volume will change at high altitude (i.e. 50 gallons at sea level isn't 50 gallons at 30,000 ft, but it's still about 330 lb). JSBSim already uses pounds for its internal calculations, so we're doing a two-way conversion right now. All the best, David -- David Megginson [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] ANN: Fuel
David Megginson [EMAIL PROTECTED] said: Hmm -- maybe you could set up a Python script to refill the tanks every few hours. Note that the FGRocket engine model used by the X-15 was already consuming fuel -- proper fuel consumption just hadn't been implemented for FGPiston yet. In flight refueling for a c172? Kewl! ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
