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Peter BarkerandClaude Opus 5
805fa9f8d0
guided_above_terrain_posvelaccel_sub.lua integrates its position target
forward by the time since the last callback. When a callback arrived
later than 2/RUN_HZ it substituted 1/RUN_HZ for the real interval:
if (dt > 2.0 / RUN_HZ) then
dt = 1.0 / RUN_HZ
end
so a callback 243ms late advanced the target by 50ms and the remaining
193ms was discarded. The position target then falls behind the clock,
and the vehicle - which tracks that target accurately - covers less
ground than the commanded speed implies.
Measured from a failing Sub.GuidedAboveTerrain run under autotest at
--parallel=16, over the 60 simulated seconds the test watches:
GUIP updates 1047 at 17.2Hz (nominal 20Hz)
late callbacks 76 of 1047 (7.3%), worst 243ms
time discarded 5.82s, so 55.08s integrated of 60.90s elapsed
distance 27.90m of an expected 30.00m, +-1.00m -> failed
The dataflash shows the loss is upstream of the controller, not in it:
the script commanded 0.495m/s and the position controller achieved
0.442m/s against a desired 0.443m/s - it tracked what it was given to
within 0.001m/s, and what it was given was slow.
Cap the step at a fixed MAX_DT instead, so ordinary jitter is
integrated honestly and only a real stall is bounded. Pinning the
simulation speedup was tried first and is not a fix: at
context_set_speedup(10) the run still lost ground, reaching 28.93m,
because it reduces how often callbacks are late without changing what
happens when they are.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
LUA Examples
This directory contains some script examples. For simulation the scripts should be placed in the simulation's "scripts" directory located in the root directory from which the sim is run. Note: if an example uses auxillary files (mission list, other scripts,etc.) the user will have to determine where the files should be placed from the script. If no path name is specified in the file name, then it should be placed one directory level above the "scripts" directory.