On Fri, 23 Sep 2011 09:47:35 -0500, Curtis wrote in message <cahtsj_edpuscxjf3m8_fbzzx4+-m8ugdahhcx9nfk+43zwd...@mail.gmail.com>:
> Hi Geoff, > > I'm starting to run low on ideas here. I assume you don't have any > crazy/severe turbulence turned on or your plots would be all over the > place. Are you running out of fuel and your engines dying? If you > open the autopilot dialog (F11) you can see the target speed and if > you have the hud turned on you can see the actual speed in any view. ..what's your autopilot, fuel load etc settings? The works, please, I suspect you have something set that we guinea pigs are missing. Is e.g. your script actually controlling both jet engines? > If you are circling with a target speed of 150 and your airspeed is > less than than and you are decending, then definitely check your > engine output. There is a fuel dialog box under the f-14b menu and > you might double check that to see if you have any fuel in your tanks. > > For what it's worth, I'm rock solid in circling and the only time I > have ever stalled out of the sky or really got out of kilter is when > I've had severe turbulence turned on. Moderate turbulence at all > levels is actually pretty interesting because despite getting thrown > all over the sky, I still hit the carrier deck pretty spot on every > time. > > Curt. > > > On Fri, Sep 23, 2011 at 9:35 AM, Geoff McLane wrote: > > > Hi Curt, > > > > Ok, removed my joystick, and entered a '5', but > > still crashed while just in 'circle' mode - no route > > entered ;=(( > > > > As usual Atlas provides a good 'view' as to > > what happened - added - > > ATLAS="--atlas=socket,out,<IP>,5500,udp" > > to output to Atlas running in a 2nd machine... > > > > See - > > http://geoffair.org/tmp/uas-01.jpg > > for a graph of the flight... > > > > The two blips in the graphs show the first stall, > > but it recovers and begins to climb back, and the > > 2nd the second stall, this time too low to recover, > > so into the drink ;=(( CRASH! > > > > This is a view of the 'crazy' flight track > > http://geoffair.org/tmp/uas-02.jpg > > > > Obviously the pig-tail loops are the 'stalls'... > > remember with NO joystick attached and starting > > with centered controls (NumPad 5)... > > > > And if you want to load this track into Atlas, or > > further study speeds, etc, then this is the > > Atlas track data :- > > http://geoffair.org/tmp/uas-01.txt > > > > Then on the NEXT flight I tried :- > > IO="--generic=file,out,10,uas-02.csv,playback" > > > > Then I added a header line, to help analyze > > it in say an OpenOffice spreadsheet import - > > see - > > > > http://geoffair.org/tmp/uas-02.csv > > > > On this 2nd flight, this crash took longer, since > > it (randomly) turned left first, where as mentioned > > it holds more stable, but then eventually went into a > > right turn, stalled, recovered, stalled again, and > > CRASHED... > > > > And as you know well, downloading this file, and > > using say - > > > > $ ./fgfs --fg-root=/point/to/fgfs/data --timeofday=noon \ > > --aircraft=f-14b-uas --carrier=Vinson \ > > --generic=file,in,10,uas-02.csv,playback --fdm=external > > > > you too can enjoy this fateful flight ;=)) > > > > In 'chase' view, you can clearly see the right roll > > increase, the nose coming up, and the stall, recovery, > > then repeated, and BANG, into the water... > > > > I know it is difficult to work on, debug, fix > > something that obviously does not happen in your > > case... > > > > Maybe if you do not enter any route, or something... > > > > And this is all with SG/FG git of 2011-09-14... > > > > Any other ideas? > > > > Regards, > > Geoff. > > > > > > On Thu, 2011-09-22 at 14:00 -0500, Curtis Olson wrote: > > > On Thu, Sep 22, 2011 at 1:25 PM, Geoff McLane wrote: > > > Hi Curt, > > > > > > A pleasure, and FUN ;=)) > > > > > > Yes, I know a low frame rate can play havoc when > > > you are trying to fine control an aircraft from > > > its attitude feedback, and I should have mentioned my > > > rate, but is always in the high 50-70 fps range in this > > > Ubuntu machine... so should NOT be a factor... > > > > > > > > > Ok, 50-70 should be perfect. > > > > > > I just did another few runs, and this time it crashed > > > just while circling... it was in a right bank, which > > > got too much and the nose came up, and it stalled... > > > I am mostly in the 'chase' view... > > > > > > > > > This is really strange. I have seen nothing like this except > > > when I inadvertantly applied external control inputs through a > > > strange combination of linux virtual desktops and flightgear > > > capturing the hotkey to come back to the FlightGear virtual > > > desktop. > > > > > > > > > So two thoughts here. If you have a joystick connected, could > > > you try unplugging it to see if that helps? Could you also press > > > "5" on the numeric keypad to make sure all the flight control > > > inputs are centered. Because of the way the F-14b FCS is wired > > > together in combination with the yasim flight surfaces, you can > > > still input elevator and aileron and trim and cause conflicts > > > that you might not see in other simpler aircraft that use aileron > > > and elevator directly. > > > > > > > > > The first time this happened at 2000 feet, it caught > > > itself - leveled a bit and bumped the throttles, and > > > began climbing back... > > > > > > But a little later, 20-30 secs, it happened again, and > > > this time was still too low to recover, and SPLASH... > > > > > > I had not previously let it fly in the 'circle' mode > > > for too long, but now note if I leave it in circling > > > mode, it will eventually end up in the water... seldom > > > lasts more than 5 or 10 minutes... > > > > > > You seem to be deliberately holding its speed down > > > around 150 - I see air-brakes come up when greater > > > than this, and throttle back - and although flaps (I think > > > full flap?) are still applied, 150 must be quite 'low' > > > for this sleek bird... > > > > > > > > > Normal landing approach in the real aircraft I believe is about > > > 120 kts? I fly 135 kt approaches in the simulator. It should be > > > able to hold 150 kts with the flaps down pretty easily. The > > > point of slowing way down when circling is to keep the circle > > > radius small enough so you can see what you are looking at. If > > > you fly the circle at 600 kts, your radius will be 20 miles (just > > > guessing) :-) and you won't be able to see anything. > > > > > > And I am not sure how many degrees each marking on > > > the hud bottom bank indicator represents, and while it > > > starts the banking in between the 1 and 2 of the 'big' > > > marks, at the stall point it is beyond the 2nd big mark, > > > approaching, even reaching the 3rd big mark, which is on the > > > horizontal - ie 90 degrees! > > > > > > At the moment of stall it loses 1200-1400 feet in 1-3 > > > seconds... while it can happen in a right or left turn, > > > it does seem to happen quicker in a right turn... > > > > > > I now understand the 'reset' is a full sim reset, > > > but that is not too helpful if you have set up say a > > > particular weather, wind or something that you want to > > > repeat... must get around to feeding that in, in > > > the command, so a reset puts it back (I hope)... > > > > > > > > > Well complain to the developers if a "reset" resets too > > > agressively. :-) > > > > > > If you could describe a bit more where some of this > > > is decided/calculated I too could try tweaking some > > > values... > > > > > > I would probably bump the speed a little, and really > > > watch the bank angle... those stubby little wings do > > > not give much lift anyway, but the slender body gives > > > close to none ;=)) > > > > > > As mentioned, I too have more than a passing interest > > > in automated flight control... > > > > > > Regards, > > > Geoff. > > > > > > PS: OT: I too searched a little for the expression to be > > > a 'bunny', but could not really find anything ;=(( > > > > > > I am sure it comes from my Australian origin, and > > > has the meaning to take the rap, take the medicine, > > > sort of to be the guinea pig... > > > > > > > > > Ok, I can understand that. Here we test cosmetics on little > > > bunnies (so I'm told) but I'm sure we have to shave all their > > > hair off first. > > > > > > Why poor little bunny rabbits feature I just do > > > not know ;=)) > > > > > > Maybe from when Australia had a big war on > > > rabbits _MANY_ years ago, and put out millions > > > of traps for the bunnies, as well as other methods, > > > like poisons - myxomatosis... > > > > > > So to be a bunny was to be trapped ;=(()) > > > > > > Maybe other Australian's have a better memory than me, > > > and can explain it better, but meantime I will blame > > > my parents, or the Australian educational system, for > > > giving me such a stupid expression ;=() > > > > > > On reading up on 'to be a Guinea Pig', another > > > very confusing expression - not really a 'pig' and not > > > from Guinea! - I found a reference that in Johnston's > > > Natural History, they go by the name Spanish Coney. And > > > 'coney' was the old name for a rabbit, a bunny... Huh! > > > > > > > > > In Peru Guinea Pig is a delicacy ... cui ... never had it myself > > > that I'm aware of. > > > > > > Maybe the early immigrants to Australia decided to mix > > > it up even more! ;=)) Or got it confused on the long > > > boat ride half way around the world... > > > > > > > > > Well just to summarize, if your frame rates are solid in the > > > 30-60+ range, then the next thing I'm wondering about is a > > > joystick or other means of extraneous control inputs that could > > > be confusing the F-14b AFCS. > > > > > > > > > Thanks, > > > > > > > > > Curt. > > > -- > > > Curtis Olson: > > > http://www.atiak.com - http://aem.umn.edu/~uav/ > > > http://www.flightgear.org - http://gallinazo.flightgear.org > > > > > > > > > > > > > ------------------------------------------------------------------------------ > > All of the data generated in your IT infrastructure is seriously > > valuable. Why? It contains a definitive record of application > > performance, security threats, fraudulent activity, and more. > > Splunk takes this data and makes sense of it. IT sense. And common > > sense. http://p.sf.net/sfu/splunk-d2dcopy2 > > _______________________________________________ > > Flightgear-devel mailing list > > Flightgear-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > > > > > ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
