Re: [Flightgear-devel] More instruments: VSI and HI
Curtis L. Olson writes: > The airspeed indicator is still working for me, even when the static > system not servicable. I haven't done an ASI yet -- I need to model the pitot system for that. > If you want to parameterize your turn-coordinator modeling code, In > the C172S (serial #'s 172S8704 and on) the turn-coordinator is fed > from the "electrical bus 2" aka: > > "/systems/electrical/outputs/bus[1]" I think that's what I'd prefer to do. Right now, everything in Instrumentation/ is hard-coded, but once the major instruments are roughed in, I'll parameterize them. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] More instruments: VSI and HI
David, Just had a look at the latest additions, good work, this is an area that has been very lacking in flightgear and it's nice to finally be addressing it. The airspeed indicator is still working for me, even when the static system not servicable. David Megginson writes: > I think I need a fresh day for that one -- it's a little complicated. > The TC will be easier as soon as I have a chance to look at Curt's new > electrical code. Your code should be able to simply check the property: "/systems/electrical/outputs/turn-coordinator" We aren't yet modeling a degraded/degrading electrical system so as long as this is > 0 you should have power. If you want to parameterize your turn-coordinator modeling code, In the C172S (serial #'s 172S8704 and on) the turn-coordinator is fed from the "electrical bus 2" aka: "/systems/electrical/outputs/bus[1]" But it will likely be someplace else in other aircraft ... even earlier serial numbers of the C172S (which I was referencing) feed the TC from bus #1. Why can't there be a universal standard for how electrical systems are constructed in aircraft?!? I know! I'll come up with a standard myself ... > Once the basic stuff's in place, we can go back and add more > features like configurable error factors and offsets (the AI on > C-GPMR shows a few degrees bank in level flight), acceleration > errors, etc. Yes, if someone could come up with a simple model of a battery, and alternator we could add those pretty easy and track power going through the system in whatever units are appropriate. Systems could start dropping off line or degrading (TC gyro?), radio displays could start dimming/flickering, etc. (do they do that?) when the power drops sufficiently. > It's going to be fun writing a randomized failure manager when > everything's ready. I can think of quite a bit, including things > that should be caught in the preflight but sometimes are not (like > reversed ailerons). Yes, and the property system makes it conventine to fire off faults in a variety of ways. We could have external scripts that could set up standard training scenarios. There are lot's of possibilities. Regards, Curt. -- Curtis Olson IVLab / HumanFIRST Program FlightGear Project Twin Cities[EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] More instruments: VSI and HI
> > However, the airspeed indication will be inconsistent and > > a full instrument scan will immediately identify the problem. > > When will you connect the ASI between the pitot and static ? > > I think I need a fresh day for that one -- it's a little complicated. > The TC will be easier as soon as I have a chance to look at Curt's new > electrical code. Ignore the reference to the scan; it ain't relevant for the subsystem. The ASI is just a differential pressure sensor indicating the difference between the pitot line and the static line. We need a lookup table to generate IAS numbers from pressure to keep panel XML design simple. > It's going to be fun writing a randomized failure manager when > everything's ready. I can think of quite a bit, including things that > should be caught in the preflight but sometimes are not (like reversed > ailerons). Remember my suggestion for multiplayer, where each participant has a single failure at all times chosen from the list of survivable failures. The other players of the multi session get to choose which failure it is, and also change their choice at any time without notice. Grin. I think that would be much more fun than a boring random selection. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] More instruments: VSI and HI
Alex Perry writes: > However, the airspeed indication will be inconsistent and > a full instrument scan will immediately identify the problem. > When will you connect the ASI between the pitot and static ? I think I need a fresh day for that one -- it's a little complicated. The TC will be easier as soon as I have a chance to look at Curt's new electrical code. Once the basic stuff's in place, we can go back and add more features like configurable error factors and offsets (the AI on C-GPMR shows a few degrees bank in level flight), acceleration errors, etc. It's going to be fun writing a randomized failure manager when everything's ready. I can think of quite a bit, including things that should be caught in the preflight but sometimes are not (like reversed ailerons). All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] More instruments: VSI and HI
> The VSI and ALT are connected to the static port. When that port is > blocked, Don't forget to put in the alternate static source switch on the panel, and cause it to read as a slightly rearward facing static port. > the ALT will freeze at its current altitude reading, and the > VSI will gradually settle to zero; that's particularly nasty, because > the two instruments will agree (no climb or descent). However, the airspeed indication will be inconsistent and a full instrument scan will immediately identify the problem. When will you connect the ASI between the pitot and static ? ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] More instruments: VSI and HI
The CVS now has new vertical-speed indicator and heading-indicator support, to go with the existing support for the attitude-indicator and the altimeter. The VSI and ALT are connected to the static port. When that port is blocked, the ALT will freeze at its current altitude reading, and the VSI will gradually settle to zero; that's particularly nasty, because the two instruments will agree (no climb or descent). The AI and HI are powered by the vacuum pump. When that pump fails, the AI will gradually settle down and to the left, while the HI will simply get more and more sluggish until it's basically still. For these gauges, the failure is very slow and subtle. The HI also precesses 360deg/day when actually spinning -- i.e. if you could fly for 24 hours straight and refuel in the air, it would do a complete circle. Note that it is not necessarily lined up with the mag compass when you start the aircraft. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
