RE: [Flightgear-devel] Data source battle?
Jon Berndt said: I don't use real weather because most of my flying is to test the fdms I'm working on, Just so I am clear, when you say fdms are you referring to Flight Dynamics Model source code, or are you referring to something I'd call an Aircraft Flight Model (AFM) or Aircraft Flight Model Definition (AFMD). I don't mean to sound snobbish, but when I think of FDM I think of math (equations of motion). The aircraft definition files - whether it be a JSBSim aircraft definition file, a YASim one, or whatever - define the aircraft - which the FDM code interprets and brings to life. We've never really discussed terminology as far as I can remember, but maybe a clarification would be good - if only so that my filter rules don't categorize messages incorrectly. :-) If it wasn't for the great work on JSBsim and YASim we'd have very few aircraft. But I think those config files, along with the source code that ends up interpreting and processing them, both make up the FDMs. There is considerable skill and effort involved in producing accurate flight models for new aircraft isn't there? Or maybe I'm just not very good at it :-) Heh...probably the later! Anyway, I knew exactly what Lee meant. Best, Jim ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Data source battle?
Jim Wilson wrote: If it wasn't for the great work on JSBsim and YASim we'd have very few aircraft. But I think those config files, along with the source code that ends up interpreting and processing them, both make up the FDMs. There is considerable skill and effort involved in producing accurate flight models for new aircraft isn't there? This is absolutely true. It's almost an art form in itself. But, the aircraft definition is a complete, static, specification file for a specific aircraft. The flight dynamics model (I'm referring to JSBSim, YASim, or UIUC-LaRCsim source code compiled into FlightGear) _implements_ the flight dynamics guided by the specific aircraft flight model. Just my $0.03. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Data source battle?
On Friday 30 July 2004 23:19, John Wojnaroski wrote: When using real-time weather via the net and the native-ctrls interface to input control data to FG it appears both sources attempt to write to the environmental properties; this is most noticeable with the wind vector and discontinuities in the ground speed turning off the specific wind properties update in native-ctrls clears up the conflict but restricts wind updates to the real-time system. Has anyone experienced this problem? Regards John W. This sounds like it may be at the bottom of some problems I've been having with weather. I don't use real weather because most of my flying is to test the fdms I'm working on, so I want predictable and consistent weather. What I'm experiencing though, is that on take-off, the wind and visibility settings are frequently incorrect for the altitude I'm at. For example, sometimes instead of getting 3 kts over the runway at start-up it's 6 kts i.e. the next layer up. Then sometimes, even if the ground layer is correct, as I gain altitude after take-off, instead of progressing through the different layers I'll get a jump as it skips a layer or two so I get 6000 ft or 9000 ft settings at 1000 ft instead of the 3000 ft settings. I can use the weather gui to correct this but I may need to click the 'Apply' button many times before the weather settings change. Then to cap it all, when I then click 'OK' to close the gui, the weather sometimes reverts back to an incorrect setting. LeeE ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Data source battle?
I don't use real weather because most of my flying is to test the fdms I'm working on, Just so I am clear, when you say fdms are you referring to Flight Dynamics Model source code, or are you referring to something I'd call an Aircraft Flight Model (AFM) or Aircraft Flight Model Definition (AFMD). I don't mean to sound snobbish, but when I think of FDM I think of math (equations of motion). The aircraft definition files - whether it be a JSBSim aircraft definition file, a YASim one, or whatever - define the aircraft - which the FDM code interprets and brings to life. We've never really discussed terminology as far as I can remember, but maybe a clarification would be good - if only so that my filter rules don't categorize messages incorrectly. :-) Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Data source battle?
On Saturday 31 July 2004 17:02, Jon Berndt wrote: I don't use real weather because most of my flying is to test the fdms I'm working on, Just so I am clear, when you say fdms are you referring to Flight Dynamics Model source code, or are you referring to something I'd call an Aircraft Flight Model (AFM) or Aircraft Flight Model Definition (AFMD). I don't mean to sound snobbish, but when I think of FDM I think of math (equations of motion). The aircraft definition files - whether it be a JSBSim aircraft definition file, a YASim one, or whatever - define the aircraft - which the FDM code interprets and brings to life. We've never really discussed terminology as far as I can remember, but maybe a clarification would be good - if only so that my filter rules don't categorize messages incorrectly. :-) Jon Hello Jon, I'm not referring to Flight Data Model source code but to the xml config for a particular aircraft - AFM/AFMD I guess. I was using that terminology because I copied it from some existing stuff. LeeE ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Data source battle?
- Original Message - From: Lee Elliott [EMAIL PROTECTED] To: FlightGear developers discussions [EMAIL PROTECTED] Sent: Saturday, July 31, 2004 8:46 AM Subject: Re: [Flightgear-devel] Data source battle? On Friday 30 July 2004 23:19, John Wojnaroski wrote: When using real-time weather via the net and the native-ctrls interface to input control data to FG it appears both sources attempt to write to the environmental properties; this is most noticeable with the wind vector and discontinuities in the ground speed turning off the specific wind properties update in native-ctrls clears up the conflict but restricts wind updates to the real-time system. Has anyone experienced this problem? Regards John W. This sounds like it may be at the bottom of some problems I've been having with weather. The problem occurs when using the native-ctrls sockets and protocols to send a control packet from the sim hardware to FG at a 24Hz rate. The native-ctrls.cxx updates the property tree with the values in the packet which may or may not be set by the sender. On the next frame, the real-time weather kicks in until the next data packet arrives. If you need or want only part of the packet you have to hack the code. There is a section of code in native-ctrls.cxx around line #386 that updates the property tree with the values in the received packet. Normally, this function should not run unless you've enabled the native-ctrls protocol and socket. Curtis posted an email about two months ago soliciting some ideas and thoughts on the whole topic of the interface between the FDMs, FG, and the network. Rework in that area would be a major effort. Especially if the idea is to provide support for a network of machines running portions of a simulator such as aircraft subsystems, displays, hardware driver interfaces, FDMs, visual systems, etc Regards John W. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] Data source battle?
When using real-time weather via the net and the native-ctrls interface to input control data to FG it appears both sources attempt to write to the environmental properties; this is most noticeable with the wind vector and discontinuities in the ground speed turning off the specific wind properties update in native-ctrls clears up the conflict but restricts wind updates to the real-time system. Has anyone experienced this problem? Regards John W. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
