- Delete left over identity matrix.
- Corner case with a zero element when using the signum function:
We always need a sign also for zero.
- Corner case with arbitrary yaw but and 180 degree roll or pitch:
Reduced attitude control calculation always rotates around roll
because there's no right choice when neglecting yaw. In that small
corner case it's better to just use full attitude contol and hence
rotate around the most efficient roll/pitch combination.
According to the paper the quaternion controller is built on
the yaw weight represents the ratio between the roll/pitch and
the yaw attitude control time constant. It also states that as a
thumb rule a value of ~0.4 works alright for most multicopter
platforms. The default attitude gains of PX4 which were determined
independent of the paper from experimental results have a ratio of
2.8/6.5 = 0.43 which matches.
Because the parameter does not make sense from a control theory
perspective. Either you have a gain with the unit 1/s or an inverse
gain or time constant with the unit s. But the time constant parameter
was neither bound to any exact unit nor did it apply instead of a gain.
Rather it adjusted multiple gains from rate and attitude control
according to an arbitrary scale. This can only by accident lead to
good tuning.
to prioritize yaw compared to roll and pitch by combining
the shortest rotation to achieve a total thrust vector with
the full attitude respecting the desired yaw
not by scaling down the control output with the gains
tested on at least 5 different vehicles, including AeroFC. The values
should be conservative, good setups (with low vibrations) can increase
these values even further.
increasing IMU_GYRO_CUTOFF allows for better tuning gains (increased P).
- make the selected parameter a template argument. This
enables type-checking at compile-time.
- move things to src/platforms.
This provides consistent includes with ModuleBase
- add ModuleParams base class (replaces Block & SuperBlock)
- drop the Block* prefix from the class names
Generates an enum with all params & additional type information for static
type checking
The generated public param header is required to build the modules using
the new BlockParam classes.
- standard vtol was implementing many custom parameters although they
are generic and should be shared between the vtol types
- removed heavy usage of hrt_elapsed_time() which is a system call and
could be computationally expensive
This fixes a problem where we do not properly go to the set takeoff
altitude but end up lower.
The problem was that the setpoint triplet is reset when the navigation
mode changes. So in this case, the triplet is reset when we switch from
takeoff to loiter which can happen before reaching the actual takeoff
altitude.
The fix is an ugly hack to prevent the reset in the case of takeoff to
loiter. A better solution would be to remove the general reset and have
all navigation modes do the proper resets themselves.
This hotfix should however be lower risk.
Matthias Grob