Develop
Ticket #466 (closed defect: fixed)
Zig-Zag Wind not working
| Reported by: | ian | Owned by: | jwharington |
|---|---|---|---|
| Priority: | normal | Milestone: | XCSoar 6.0.x |
| Component: | Other | Version: | 6.0a |
| Keywords: | Zig Zag Wind | Cc: | ian-xcsoar@… |
Description
Zig-Zag wind calculation seems to have stopped working with version 6.0 alpha 1.
I have a attached a raw log file from the first approx 1 hour of a flight. Flight was recorded with an HP4700 connected to a Borgelt B500 with wind data. When I replay this flight I can see true airspeed and ground speed in info boxes, but with wind to "Zig-Zag" only, no wind is detected or displayed.
The same log file replayed on version XCSoar 6.0 build 2010-09-29 displays Zig-Zag wind data after several minutes of aerotow.
Note I have my suspicions about Zig-Zag wind calcs on build 2010-09-29 too. On a previous flight, when descending from wave (where it correctly displayed a high wind speed) onto a ridge, were wind was much less, the old data was displayed until circling flight caused a wind update. I have another long raw log file which demonstrates this. I will retest this when Zig Zag is working on the latest version again.
Attachments
Change History
Changed 3 years ago by ian
- Attachment xcsoar-nmea-short.log.zip added
comment:1 Changed 3 years ago by ian
- Cc ian-xcsoar@… added
I just noticed ticket 451
http://www.xcsoar.org/trac/ticket/451
This may be related to my comments in the 2nd half of this ticket.
comment:2 Changed 3 years ago by max
I've tried the large file you emailed to me, and XCSoar shows ~ 290 degrees, 70 km/h wind. Is that correct?
Please check if you configured Borgelt B50 on the configuration dialog. Without this setting, XCSoar cannot see the airspeed, and disables ZigZag? calculations.
Changed 3 years ago by ian
- Attachment xcsoar-nmea-section.log.zip added
Correct Raw log file section: (1.2MB "xcsoar-nmea.log")
comment:3 Changed 3 years ago by ian
I have just uploaded another raw log. The file I uploaded previously had the wrong flight segment. Please use the new upload instead. It contains a 1.2MB file "xcsoar-nmea.log".
This is a section of a flight with wave/ridge/thermal/wave flight. There are significant wind changes with altitude.
If you:
- Configure Device type to Borgelt B50
- Configure "InfoBox?" windows to display "Airspeed TAS" and "Speed ground"
- Configure Auto wind to "ZigZag?"
Then replay this new raw log at speed x1, the problems should be apparent. Note by comparing TAS and Ground speed displays, you can detect when wind speed changes. (You can also replay again with Circling wind set for confirmation of the actual wind speeds.)
The whole replay takes a long time. But the problems become apparent sooner.
I have tested this with:
- Version 6.0_alpha3: No wind speed data shows at all
- Version 2010-09-29: Wind data shows after several minutes in wave but is not correctly updated later in the flight.
If anyone would like to see the terrain/airspace file that I use, I can make it available (it might make the replay look more realistic).
comment:4 Changed 3 years ago by jwharington
- Owner set to jwharington
- Status changed from new to assigned
comment:5 Changed 3 years ago by jwharington
Have run your log through the algorithm, results in zigzag.png attached. Looks like the algorithm is working to me, the problem may be elsewhere in xcsoar.
comment:6 Changed 3 years ago by ian
I tried this with version 6.0_alpha6. Things are looking a lot better. The raw log replay as described above yielded very plausible readings.
I then flew a 380km ridge flight with this version on Saturday. Both Zig-Zag and Circling wind were enabled. I got regular wind updates while flying straight on the ridge. (Wind speed varied between 6km/hr and 37km/hr and wind direction varied by 90 deg along the task). When I did occasionally stop to thermal, the circling did not radically change the wind speed reported. I think this bug can be marked as "fixed". :-)
But Xcsoar froze completely after about 280km. Clearly still an "alpha" version. Next flight I will be ready to press the soft reset button, if required. :-(
Raw log file