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Re: Concorde cockpit redesign

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Re: Concorde cockpit redesign

Postby legoboyvdlp » Mon Jan 21, 2019 8:09 pm

That's because static and total pressure are ambient, not local - they change with altitude / speed.
What is concerning is this:

Image

Notice sea level pressure is constant. So, it's not METAR at fault. It must be the atmosphere / aloft winds / AW interpolation and strange effects due to all three combined.

Image
See how altitude and speed jump - did you (or AP) do this or was this a jump?


This is not of concern:

Image

This is wind going from above 360 to below 360.


Wind direction getting "stuck", then jumping at 1800 seconds is somewhat concerning though.
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Re: Concorde cockpit redesign

Postby V12 » Mon Jan 21, 2019 9:13 pm

It was AP mode change from VS climb to IAS hold climb on 400 kts. It is bug in the original AP code. Main problem is jump change static and total pressure while sea level pressure is constant - first picture in Your previous post.
In my previous post I mentioned this behaviour as not understandable for me. Not smooth static and total pressure change with speed and altitude without sea level pressure change.
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Re: Concorde cockpit redesign

Postby V12 » Tue Jan 22, 2019 6:42 am

I analyzed recorded data and found that designated steep changes are connected :

Image

In this case it is not AW routines problem.
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Re: Concorde cockpit redesign

Postby V12 » Tue Jan 22, 2019 6:49 pm

Today test flight from EGLL to LPMA with subsonic part, supersonic part over open ocean and part near coastal line - check https://fgtracker.ml/modules/fgtracker/ ... ID=7081724

Chart with sea level pressure and indicated altitude - You can see that not all sea level pressure changes biased indicated altitude :

Image

Other data in the file https://ulozto.net/!YVvsh91lXa0C/egll-lpma-ods
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Re: Concorde cockpit redesign

Postby legoboyvdlp » Tue Jan 22, 2019 7:17 pm

Comparing static pressure as well would be more useful: the altimeter uses static pressure as its source of altitude.

I'll open the spreadsheet and try and add that to the graph.

Edit - oh, I see why now :/ Sorry!
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Re: Concorde cockpit redesign

Postby legoboyvdlp » Tue Jan 22, 2019 7:31 pm

This is the most concerning discontinuity: again wind dircection and speed:

Image

That should be interpolated I'm sure...

And the moment of the jump in raw data:

Image


what resoloution is this data - every second?
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Re: Concorde cockpit redesign

Postby V12 » Tue Jan 22, 2019 7:56 pm

Yes, 1 sec interval.
There is one strange fact - sometimes wind dir and speed interpolation works, other times doesn't. After Your designatet discontinuity interpolation clearly doing good job.
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Re: Concorde cockpit redesign

Postby legoboyvdlp » Tue Jan 22, 2019 8:04 pm

I can't do logging myself: FlightGear crashes when I enable it... :?
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Re: Concorde cockpit redesign

Postby V12 » Tue Jan 22, 2019 8:13 pm

I'm logging via generic protocol and this command :
--generic=file,out,1,fdr.csv,fdr

here is fdr protocol :
Code: Select all
<?xml version="1.0"?>
<PropertyList>
 <generic>
  <output>
   <line_separator>newline</line_separator>
   <var_separator>:</var_separator>
   <chunk>
    <name>METAR</name>
    <type>string</type>
    <format>%s</format>
    <node>/environment/metar/station-id</node>
   </chunk>
   <chunk>
    <name>Indicated alt</name>
    <type>float</type>
    <format>%f</format>
    <node>/instrumentation/altimeter[0]/indicated-altitude-ft</node>
   </chunk>
   <chunk>
    <name>Pressure inhg</name>
    <type>float</type>
    <format>%f</format>
    <node>/environment/pressure-inhg</node>
   </chunk>
   <chunk>
    <name>Pressure sea level ingh</name>
    <type>float</type>
    <format>%f</format>
    <node>/environment/pressure-sea-level-inhg</node>
   </chunk>
   <chunk>
    <name>KIAS</name>
    <type>float</type>
    <format>%f</format>
    <node>/instrumentation/airspeed-indicator[0]/indicated-speed-kt</node>
   </chunk>
   <chunk>
    <name>TAS </name>
    <type>float</type>
    <format>%f</format>
    <node>instrumentation/tas-indicator/indicated-speed-fps</node>
    <factor>0.592484</factor>
   </chunk>
   <chunk>
    <name>GS </name>
    <type>float</type>
    <format>%f</format>
    <node>/velocities/groundspeed-kt</node>
   </chunk>
   <chunk>
    <name>wind direction</name>
    <type>float</type>
    <format>%f</format>
    <node>/environment/wind-from-heading-deg</node>
   </chunk>
   <chunk>
    <name>wind speed</name>
    <type>float</type>
    <format>%f</format>
    <node>/environment/wind-speed-kt</node>
   </chunk>
   <chunk>
    <name>stat_pressure</name>
    <type>float</type>
    <format>%f</format>
    <node>/systems/static[0]/pressure-inhg</node>
   </chunk>
   <chunk>
    <name>total_pressure</name>
    <type>float</type>
    <format>%f</format>
    <node>/systems/pitot[0]/measured-total-pressure-inhg</node>
   </chunk>
  </output>
 </generic>
</PropertyList>
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Re: Concorde cockpit redesign

Postby legoboyvdlp » Tue Jan 22, 2019 8:45 pm

Ok - I saw one... I was at 2.02 / 51400 in cruise climb, checked discord momentarily, came back and was at 2.01 / 51200...

edit: now 50900 after 20 minutes cruiseclimb +50 fpm.
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Re: Concorde cockpit redesign

Postby V12 » Thu Jan 24, 2019 1:28 pm

Next FGFS AW absurdity :

Today, I performed flight from EGLL to KJFK - flight log is here - https://fgtracker.ml/modules/fgtracker/ ... ID=7082348 and recorded data https://ulozto.net/!ibsnbYJR4UAk/egll-kjfk-20180124-ods. Here is chart of the presure changes :

Image

Static (red) and total pressures (yellow) are on left Y axis, sea level pressure (blue) on right Y axis. After largest sea level pressure change indicated altitude jumped more than 1000 feets. This pressure step occured on CYYT METAR station record numbers 6980-6982. There was another large pressure jump, but after METAR station change. This is clear evidence of live weather with live wind aloft importance. Something like Active Sky, or freeware FSXWX.
Autopilot handled this changes without problems, because I made MAX Cruise mode based on vertical speed indicated by GPS (pretty unrealistic, GPS was not available in the Concorde age). If I use Alt Hold AP mode, result is clear - AP disengage in the better case, or crash in other case.

Altitude, airspeedd and wind chart :

Image
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Re: Concorde cockpit redesign

Postby legoboyvdlp » Thu Jan 24, 2019 2:15 pm

ok - can you do this:

(restore your original local-weather.nas without the updates I asked you to do from https://sourceforge.net/p/flightgear/fg ... eather.nas first please)

First check /local-weather/interpolation-loop-flag and report its value.

Next check /local-weather/config/fps-control-flag and report its value

If the value of /local-weather/interpolation-loop-flag 1: replace the blank line 425 with
Code: Select all
print("Interpolation loop running!");


This should occur at framerate: sorry that it will spam your console, but if it stops, you know there is a problem.

This is very basic but makes sure the loop is running properly.



Also, to confirm, you are using winds aloft waypoint interpolated? Not aloft interpolated, constant in tiles?

@mod, maybe this could be split to "Advanced Weather debugging in the concorde" or something like that?
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Re: Concorde cockpit redesign

Postby V12 » Thu Jan 24, 2019 3:50 pm

This is not Concorde specific problem, but general.
OK, let's continue at viewtopic.php?p=341864#p341864
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