Hi,
not sure if anyone else had a chance to test the "instant replay" with
JSBSim aircraft - but it indeed seems like a general issue to me. It's
triggered by JSBSim doing a "trim" operation once playback has
finished - which produces an output like this (with the F16 in this
case):
Trim Results:
Altitude AGL: 15 wdot: -1.83e+08 Tolerance: 1e-03 Failed
Pitch Angle: -19 qdot: 9.33e+07 Tolerance: 1e-04 Failed
Trim Statistics:
Total Iterations: 61
Sub-iterations:
wdot: 0 average: 0 successful: 0 stability: 3.5272
qdot: 0 average: 0 successful: 0 stability: 3
Run Count: 1201
Soon afterwards, the entire sim locks up since the FDM numerics go
wild. I can avoid this issue by suppressing the re-trim when replay
has finished (by forcing "needTrim = false;" in the code). All works
well for me then - but it completely kills the "needTrim" feature in
JSBSim, which was probably implemented for a reason...
The trim is triggered since the FDM still has its property listeners
connected during replay - so it thinks the aircraft position changes,
which sets the FDM's "needTrim" flag. Might be a good idea to
disconnect the FDM property ties during a replay - but JSBSim
currently doesn't allow to reconnect the ties ("bind" method is not
implemented). And the basic problem here probably is just that
something with re-trimming an aircraft doesn't work properly.
Any ideas on what could go wrong when the FDM tries to trim an already
trimmed aircraft?
cheers,
Thorsten
On Sun, Mar 20, 2011 at 12:48 PM, ThorstenB <bre...@gmail.com> wrote:
> I'm seeing an issue with the "instant replay" feature which seems to affect
> JSBSim aircraft. The actual replay works, but once replay is finished, the
> sim locks up or goes wild when trying to resume normal flight. Looks to me
> as if the FDM was somehow messed up by the replay. The FDM's update is
> suspended during replay - but I suspect there may be an issue with the tied
> properties, which still allow the FDM to see the replayed movements. YASim
> aircraft seem to be fine though.
------------------------------------------------------------------------------
Colocation vs. Managed Hosting
A question and answer guide to determining the best fit
for your organization - today and in the future.
http://p.sf.net/sfu/internap-sfd2d
_______________________________________________
Flightgear-devel mailing list
Flightgear-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
