ahOn Mon, 2002-06-10 at 15:58, Jim Wilson wrote: > James Turner <[EMAIL PROTECTED]> said: > > > (I want to get the flight-plans hooked up to the existing > > auto-pilot code, which isn't really designed to look like a 'big jet' > > model of course, though it seems you already have code *somewhere* that > > handles LNAv and VNAV functions... hmm. > > You might want to hold off on that piece for now, the autopilot code is > getting re-written. The current code will follow the waypoints in the current > waypoint list. But, if you want to do this in the most flexible way, it seems > that your subsystem should be feeding the autopilot lower level target data as > required (i.e. modes, headings, pitches, altitudes), through the property > interface. The new code will still follow radials and probably the current > waypoint functionality will remain, so you could always feed target data > through the waypoint interface.
You are correct that I need to be feeding radials / desired ground tracks / speeds / FLs to the autopilot code. The current waypoint code seems pretty misplaced though (translation, I think it should go). No real auto-pilot deals with 'waypoints', that's what an FMS does (which is precisely the systems I'm trying to model). The FMS just feeds the autopilot control commands such as course to fly and so on. (Here I'm treating the autopilot as 'the thing you interact with via the MCP' ...the autopilot has a NAV mode but that's equally happy being driven by a VOR). Anyway... One valuable thing would be to define the 'input' property nodes the auto-pilot code will have, so I know what I should be setting. *Ideally*, thus would be broken down into LNAV / VNAV / auto-throttle stuff (with some coupling, obviously, especially for managed climb and LOC/APP modes). And of course, some of these can be missing. IIRC, someone (Alex?) mentioned that on low end Cessnas, the autopilot will only control laternal navigation (no VNAV). And of course lots of GA aircraft don't have an auto-throttle. > > As far as "autopiloting" is concerned, I'm not sure of the extent of what you > are trying to model. AFIK, even if you've filed a plan and are using a flight > computer you still need to clear before climbing or descending, so > automatically changing FL and going into climb or descent when a given > waypoint is reached would not be accurate behavior. But perhaps I am > misunderstanding this. Err, I'm simply planing to copy the features I am familiar with from using the simulated FMCs and MCDUs I've used. As you say, flight level changes require ATC interaction (usually), but there's all kinds of other things that the FMS can do automatically. Even the lowly KLN-89b can automatically trigger the missed-approach for a stored procedure if it detects a go-around condition. If you're interested, you can download the manuals for various simulations (notably the Wilco 767-PIC), in PDF format. It's rather heavy going, but potentially valuable prior to auto-pilot work, I guess. James _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
