Re: [Flightgear-devel] ummm...anyone read this?
On Fri, 18 Jan 2002 09:48:17 -0800 Andy Ross [EMAIL PROTECTED] wrote: David Megginson wrote: Jim Wilson writes: The values I have to able to set per aircraft (to start with) are: min_climb_speed, best_climb_speed, target_climb_rate, and something which for lack of a better term is an elevator_adjustment_factor (controls the severity of adjustment to elevator-trim for a given error). Does anyone know any technical terms for these? They sound pretty technical and well-described to me. I'm no big fan of adherence to convention -- that's what got us slugs, for goodness sake. :) Actually, there's a point here: do autopilots really have a trim to speed option? This would strike me as almost a waste -- a given trim setting *defines* an indicated speed. Most autopilots I've seen simply trim to a given climb rate, and cut out if the airspeed drops too low or climbs too high. Some autopilots on big jets have a speed control, but that works by varying the throttle, not the trim. My notion of an autopilot would be (forgive me if this is already implemented somewhere): + Turn rate target set according to heading mode (wing leveler, heading hold, NAV, ILS) + Climb rate target set manually. + Roll control to a given turn rate. + Yaw control to coordinated flight. + Pitch control to a given climb rate. Is anything more elaborate really needed? Even really fancy fly-by-wire systems present a user interface that looks essentially like this. .maybe have it read, and fly flight plans? Tweaks could include responding to ATC input, such as amended clearances... and maybe report back... .FG _is_ lan capable, so we're not too far away. :-) -- .med vennlig hilsen = with Kind Regards from Arnt... ;-) Scenarios always come in sets of three: best case, worst case, and just in case. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ummm...anyone read this?
Jim Wilson writes: The values I have to able to set per aircraft (to start with) are: min_climb_speed, best_climb_speed, target_climb_rate, and something which for lack of a better term is an elevator_adjustment_factor (controls the severity of adjustment to elevator-trim for a given error). Does anyone know any technical terms for these? All the best, David -- David Megginson [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] ummm...anyone read this?
Hi all, Was thinking it'd be nice to have a least a minimal heading and altitude hold autopilot working for LWCE. What would be the best file and property tree location to put these values in so that the existing autopilot routine is somewhat adjustable by aircraft? See notes below. Best, Jim Jim Wilson [EMAIL PROTECTED] said: I've got some values that seem to work in the current autopilot code with the c310. They are: min_climb = 85.0 kts best_climb = 107.0 kts TargetClimbRate = 1500 fpm Also there is this adjustment factor (code snippet from newauto.cxx aprox line 697): // calculate proportional error prop_error = error; prop_adj = prop_error / 4000.0; The numbers for the c172 are 70, 75, 500, 2000.0 (in the same order as those listed above). If someone could spec the XML (which file and keywords) I'd be glad to modify the autopilot code to use them. What should this adjustment factor be called? It basically strikes a balance in a simplistic way between over and under adjusting elevator trim. It's not as good as it could be, but it'll provide a basic altitude hold function for now. Best, Jim ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Jim Wilson - IT Manager Kelco Industries PO Box 160 58 Main Street Milbridge, ME 04658 207-546-7989 - FAX 207-546-2791 http://www.kelcomaine.com ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ummm...anyone read this?
Was thinking it'd be nice to have a least a minimal heading and altitude hold autopilot working for LWCE. What would be the best file and property tree location to put these values in so that the existing autopilot routine is somewhat adjustable by aircraft? See notes below. Well, I've cobbled together a 3-axis autopilot I'm using to fly the c310 while working on the glass cockpit displays. It has a attitude hold mode, heading hold mode and a few keyboard commands to change the command values. Bad news it runs over a LAN, and would need a little work to stick into the FG autopilot code. FWIW if interested I'll be glad to send along the control laws and gains. Inputs are the FDM state variables, control surface positions, a couple of state derivatives, and command values. Output is commanded control surface deflections. Has a rudder trim and yaw damper function to handle pFactor. The whole package includes the network interfaces (UDP/TCP/IP) needed to get the state variables and return the command inputs via sockets. You could run it on a second machine to control FG. The tar file is about 200K. Regards John W. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ummm...anyone read this?
What I was looking for right now was the simple autopilot that is already in FG...ie something to keep the plane in the air when I let go of the yoke (besides pause :)). I agree it should be done right, but I can get the existing one (which is very basic) working for both c172 and c310 with very few changes. All I need to know is where the XML settings should go. They can always be expanded on. The values I have to able to set per aircraft (to start with) are: min_climb_speed, best_climb_speed, target_climb_rate, and something which for lack of a better term is an elevator_adjustment_factor (controls the severity of adjustment to elevator-trim for a given error). Best, Jim John Wojnaroski [EMAIL PROTECTED] said: Was thinking it'd be nice to have a least a minimal heading and altitude hold autopilot working for LWCE. What would be the best file and property tree location to put these values in so that the existing autopilot routine is somewhat adjustable by aircraft? See notes below. Well, I've cobbled together a 3-axis autopilot I'm using to fly the c310 while working on the glass cockpit displays. It has a attitude hold mode, heading hold mode and a few keyboard commands to change the command values. Bad news it runs over a LAN, and would need a little work to stick into the FG autopilot code. FWIW if interested I'll be glad to send along the control laws and gains. Inputs are the FDM state variables, control surface positions, a couple of state derivatives, and command values. Output is commanded control surface deflections. Has a rudder trim and yaw damper function to handle pFactor. The whole package includes the network interfaces (UDP/TCP/IP) needed to get the state variables and return the command inputs via sockets. You could run it on a second machine to control FG. The tar file is about 200K. Regards John W. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] ummm...anyone read this?
What I was looking for right now was the simple autopilot that is already in FG...ie something to keep the plane in the air when I let go of the yoke (besides pause :)). I agree it should be done right, but I can get the existing one (which is very basic) working for both c172 and c310 with very few changes. All I need to know is where the XML settings should go. They can always be expanded on. Well, okay. sorry I can't help you with the XML stuff or the numbers. The network interface code is in the CVS and the package includes a simple makefile. Just need to add a *--socket=* to the command line or whatever to set the sockets (assuming you have a network) so if you change your mind give a holler. regards John W. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
