I did say there is scope for confusion Please amend my post to say yaw to starboard (right) is positive. I lost my pair of green and red socks which normally serve to remind me on this matter.
With a red (and green) face. Alan -----Original Message----- From: Alan Teeder Sent: Friday, May 03, 2013 7:07 PM To: FlightGear developers discussions Subject: Re: [Flightgear-devel] about fdm properties For the sideslip question there is a well established sign convention. JSBSim at least should follow that exactly as it mechanises the equations of motion that are in use industry wide. The convention is Sideslip is positive when the sideslip is to starboard. In other words Sideslip angle Beta = V/U Note, as ever there can be confusion. The main confusion is between yaw and sideslip. Yaw to port is positive. If the aircraft is given positive yaw, but maintains flight in the original direction, then it will have negative sideslip, as the sideslip is to starboard. I think that you a right in assuming that the developers are not interested in the FDMs. I posted this a week ago http://sourceforge.net/mailarchive/forum.php?thread_name=C6C640DA467C4D118C9A794C6A46D433%40AlanPC&forum_name=flightgear-devel and have not seen a single comment. It exposes a serious problem in JSBSim which affects all Datcom users. Perhaps eye-candy and endless mud slinging about the merits of various renderers is a more interesting subject. -----Original Message----- From: jean pellotier Sent: Friday, May 03, 2013 6:35 PM To: FlightGear developers discussions Subject: [Flightgear-devel] about fdm properties Hi the quiet mailing list :) here are some questions about the fdm properties : - How come some fdm properties don't have the same meaning, dépending the fdm used? i'm thinking of properties in the following property trees: /accelerations /orientation /velocities /position if you want some examples, you can have a look at the bug reports 202: http://code.google.com/p/flightgear-bugs/issues/detail?id=202 and 901: http://code.google.com/p/flightgear-bugs/issues/detail?id=901 those are properties i needed to use and found buggy, but they could not be the only one affected. - is there anybody among the dev interested in this area of FG anymore? despite the bug report and the solution proposed, nothing change, except the need to have external patch to have this right. - would it be a good idea to document those properties somewhere? if so i can make a list, but i would let the description to english native users. imho, this make FG broken in some area (like hud trajectory marker with jsbsim for the sideslip, or the reported speed in radar2 for yasim planes) but the only comments i got in the bug reports were "what will it break to put it right". jano ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel