Because based on the numerous complaints it was disabled by default
(only velocities above 10m/s were limited)
and since then no one intentionally used it anymore. But
there were some minor investigations of drones not reaching
their maximum speed which always showed 10m/s.
In some cases e.g.: (VTOL in wind) a good tracking cannot be
achieved. This condition then needs to be relaxed, otherwise the
drone cannot land properly.
Before #14212 the velocity control gains used in the multicopter
position controller were defined as a scale between velocity error in
one axis (or it's integral and derivative respectively) and the unit
thrust vector. The problem with this is that the normalization of the
unit thrust vector changes per vehicle or even vehicle configuration
as 0 and 100% thrust get a different physical response. That's why
the gains are now defined as scale between velocity error
(integral/derivative) and the output acceleration in m/s².
This mode was just kept as an example after
its usage in a single case. It's basically untested
and doesn't make much sense anymore since it's
incompatible with the jerk limited trajectory
implementations. It's implementation only switched
hte configuration parameter of the velocity resulting
from maximum stick deflection to be
MPC_XY_VEL_MAX instead of MPC_VEL_MANUAL.
This is according to todays understanding undesired
because when hitting that limit the position
controller has no room for corrections anymore.
Also it saves some flash space on omnibus to remove
the task at this point and makes romm for the
acceleration feed-forward.
* MC_HTE: unitialize with hover_thrust parameter
* MC_HTE: constrain hover thrust setter between 0.1 and 0.9
* MC_HTE: integrate with land detector and velocity controller
* MCHoverThrustEstimator: Always publish an estimate even when not fusing measurements. This is required as the land detector and the position controller need to receive a hover thrust value.
* MC_HTE: use altitude agl threshold to start the estimator
local_position.z is relative to the origin of the EKF while dist_bottom
is above ground
Co-authored-by: bresch <brescianimathieu@gmail.com>
used back in time when no soothing was done to avoid large steps when
the estimator stops sending a maximum velocity (e.g.:GPS gained during
optical flow flight). Since smoothing is applied later, this is not
required anymore.
- vehicle will fly less aggressive
- it does not make sense to set the lower acceleration limit to something
that exceeds gravity if most of the vehicles do not support reverse thrust
Signed-off-by: RomanBapst <bapstroman@gmail.com>
- we have set the maximum yaw-rate MC_YAWRATE_MAX to 200 degrees and it
makes senses to leave a bit of margin between what the user can demand
and what the limits of the vehicle are
Signed-off-by: RomanBapst <bapstroman@gmail.com>
the vehicle yaws towards the next waypoint before accelerating. This is
required for drones with front vision and aerodynamic multicopters such
as standard vtol planes or highspeed multirotors.
Matthias Grob