On Wed, 2006-04-05 at 07:33 -0500, Jon S. Berndt wrote: > While debugging the 737 I discovered something that I find unsettling. For > the 737-300 model (using a JSBSim flight model) there is a nasal script > called air-ground.nas. This apparently adds some automatic control of the > spoilers while on the ground. Now, understand up front that the discussion > that follows is not about nasal (which is a great feature and a great part > of flightgear) but about compatibility, convention, and communication. > > JSBSim has a powerful flight control capability that is specifically > designed for purposes such as that which the mentioned nasal script > addresses. I'd much prefer that such code be done using that capability, and > for several good reasons. Among them: > > 1) It is desirable for debugging and development purposes that the flight > model operates as closely as possible to the same whether run from > FlightGear or from a standalone version of JSBSim. JSBSim code does not > incorporate nasal in its standalone executable. > 2) Similarly, uses of the flight models by other simulators which use JSBSim > may not incorporate nasal, and thus behavior will differ. > 3) Without knowing about such scripts (which I did not until recently), > similar capabilities may be added to the existing flight control > specification already in JSBSim and may result in a "force fight" or > controls confusion. FlightGear has an autopilot model, now there are nasal > scripts that may perform flight control related tasks, and there is the > flight control specification in JSBSim aircraft. Ideally, some emerging > JSBSim aircraft will model their own autopilot within the JSBSim flight > control model (which has been conceived and designed with an aim towards GNC > analysis from the start). So, there needs to be good communication among > several parties when it comes to adding capabilities to a flight model. > > Jon
Hi Jon, Thanks for the heads-up. As a newbie aircraft designer I am coming close to needing some automatic flight control systems for my F-4E model. For example, flaps and slats deploying when airspeed is less than 230 kcas with the gear down. Slats deploying anytime alpha exceeds 10 degrees... Is there a working example of doing this the 'right way'? Is there some documentation I haven't found yet? Perhaps http://jsbsim.sourceforge.net/AutomaticFlightInJSBSim.pdf ? Thanks, Ron http://www.jentronics.com/fgfs ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
