when on landing approach we estimate time to flare based on two noisy
numbers, the vertical speed and height above ground. With noisy
rangefinders this can change rapidly, which resulted in the pitch
limit changing rapidly, leading to a porpoising movement
this limits the rate of change, and also prevents it coming down once
it has nosed up due to pending flare on approach
The calculation of the non-limited airspeed rate demand used the last
non-limited airspeed, whereas it should have used the last adjusted
value. This led to a single frame spike in airspeed demand, which fed
through to a sudden change in pitch integrator.
a short term spike in the derivative of speed demand could cause the
constraint on the pitch integrator to push the pitch integrator to
very low values, causing a sharp nose down which takes a long time to
recover from
this will reduce confusion when searching for FLIGHT_LAND_* and you get a bunch of takeoff related hits. It will also make more sense when the landing library fully manages the FLIGHT_LAND stage entirely because it will not mange FLIGHT_LAND_ABORT
This should fix CID 91386.
Before removing the 'if', I checked the log to confirm that both branch
didn't end-up being equal by mistake in some commit. But it looks like
the file was added in the project this way.
during the first part of a takeoff when we have not yet reached the
target airspeed this forces the throttle to maximum. This fixes a case
where the throttle may drop too low during the first part of takeoff
and lead to a stall.
recent fixes in Plane have made the stage more accurate so exceptions/hacks are no longer needed to differentiate between knowing if executing NAV_LAND vs being in stage_approach.
we now can exit an underspeed condition if we stay above min speed for
3 seconds and also reach 15% above min speed. This prevents a problem
with the thrust line causing downpitch leading to a crash due to too
much throttle
- throttle slew rate was using % full range including the negative range (-100 to +100 instead of 0 to 100) which meant it was faster
- throttle integrator windup limit was higher than normal because it's a porportional to throttle max - min but that makes no sense when min is negative causing larger limits
// @Description: This is the damping gain for the pitch demand loop. Increase to add damping to correct for oscillations in speed and height. If set to 0 then TECS_PTCH_DAMP will be used instead.
+ // @Description: This is the damping gain for the throttle demand loop during and auto-landing. Same as TECS_THR_DAMP but only in effect during an auto-land. Increase to add damping to correct for oscillations in speed and height. When set to 0 landing throttle damp is controlled by TECS_THR_DAMP.
// @Description: When zero, the flare sink rate (TECS_LAND_SINK) is a fixed sink demand. With this enabled the flare sinkrate will increase/decrease the flare sink demand as you get further beyond the LAND waypoint. Has no effect before the waypoint. This value is added to TECS_LAND_SINK proportional to distance traveled after wp. With an increasing sink rate you can still land in a given distance if you're traveling too fast and cruise passed the land point. A positive value will force the plane to land sooner proportional to distance passed land point. A negative number will tell the plane to slowly climb allowing for a pitched-up stall landing. Recommend 0.2 as initial value.
Reverse thrust for controlled landings, even with much steeper approach slopes. This is achieved by allowing throttle demand to go negative to maintain a target airspeed. A Pre-Flare stage was added, triggered by an altitude, to allow for a slower airspeed just before land. That lower airspeed can be near stall.
new params TECS_APPR_SMAX - sink rate max during approach
The problem with using min() and max() is that they conflict with some
C++ headers. Name the macros in uppercase instead. We may go case by
case later converting them to be typesafe.
Changes generated with:
git ls-files '*.cpp' '*.h' -z | xargs -0 sed -i 's/\([^_[:alnum:]]\)max(/\1MAX(/g'
git ls-files '*.cpp' '*.h' -z | xargs -0 sed -i 's/\([^_[:alnum:]]\)min(/\1MIN(/g'
Now variables don't have to be declared with PROGMEM anymore, so remove
them. This was automated with:
git grep -l -z PROGMEM | xargs -0 sed -i 's/ PROGMEM / /g'
git grep -l -z PROGMEM | xargs -0 sed -i 's/PROGMEM//g'
The 2 commands were done so we don't leave behind spurious spaces.
AVR-specific places were not changed.
we should use baro height not hgt_afe for the climb rate filter. This
makes the climb rate consistent with the one from the EKF. The lidar
correction comes in with the demanded height, not the observed height
This commit changes the way libraries headers are included in source files:
- If the header is in the same directory the source belongs to, so the
notation '#include ""' is used with the path relative to the directory
containing the source.
- If the header is outside the directory containing the source, then we use
the notation '#include <>' with the path relative to libraries folder.
Some of the advantages of such approach:
- Only one search path for libraries headers.
- OSs like Windows may have a better lookup time.
this moves the pitch constraint smoothly between unconstrained and
fully constrained over two time constants before the flare. This
greatly reduces the sudden pitch changes at flare
this predicts ahead the height demand for landing, where we have a
continuous demanded descent. This removes the effect of the lag
introduced by the height demand filters
The introduction of the height rate flare logic caused the demanded height rate to be zero except when a flare manouevre was being performed. This caused the plane to lag behind height changes if the D gain was non-zero, which caused it to fly high during landing approach.
Andrew Tridgell
Peter Barker
Michael du Breuil
Nathan E
JU Han
Andrey Kolobov
Tom Pittenger
Mathieu OTHACEHE
AndersonRayner
Murilo Belluzzo
Michael du Breuil
Don Gagne
Jonathan Challinger
Lucas De Marchi
Caio Marcelo de Oliveira Filho
Gustavo Jose de Sousa
Peter Barker
Michael du Breuil
priseborough
Andrew Tridgell