Mathias Fröhlich said: > On Montag, 5. April 2004 03:02, Andy Ross wrote: > > I'm happy to dumb down the existing AGL property, but we should pick a > > new name for the "gear altitude" property, which is IMHO a much more > > interesting value. > To me there arises the question which gear do you take for this? The nose gear > for example will have a different agl then any other gear depending on the > orientation of the aircraft. > > > We should also pick a coordinate origin to report it relative to. If > > JSBSim is using the (moving) c.g., then we're both bugged. :) > Yep you are right, on my list of improvements to JSBSim there is a 'sensor > location' config option. Not really thought about this in deep and not > started to ask for the others' opinions. > > This would solve this problem too. > Just define a sensor for the altitude. > And define a reference point where this radar altitude sensor will compute its > reference height to (I don't know how these radar sensors realy work ...). > > I think one needs to distinguish between values which define the /hard/ > position of the aircraft (lat/lon/radius is sufficient or may be > lat/lon/altitude). These hard values can be read and set from flightgear. > And /soft/ values, only required for instruments/autopilot ... The soft values > are read only to flightgear. They are just the result of the aircraft > configuration when the aircraft's position is set to the hard ones. > The soft ones do not need to be consistent with any other values without > knowledge of aircraft internals (FG should not expect that > sensor_agl+groundlevel==altitude+sea_level). > Note that I only suggested a nonredundant set of values for the hard values: > no agl here. So here the consistency question does not arise. > > This would also mean that flightgear cannot just set the agl of an aircraft in > the FDM. If flightgear wants to do that, it has to compute the altitude and > set that instead. >
This sounds like it might be excessive. We should continue to model instrumentation in flightgear. Nothing more on this is needed from the FDM (we should only be translating to sensor points _if_ the particular aircraft models the instrument). That translation could easily occur in a Instrumentation/ subclasses. It would then be standardized across FDM's, which is why it is not advisable to increase the complexity of the FDM interface. We're having enough trouble keeping what we have standard. Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
