This is a first baseline implementation for collision avoidance with aircraft equipped with transponders. Since the drone-to-drone and drone-to-airplane system will be regulated by a standard, we do carefully avoid to do anything too fancy. This implementation allows to reduce altitude to get close to ground and land immediately or RTL. This is similar to what a human pilot would do and allows to get out of manned airspace which is at higher altitudes.
The mixer was creating a new class in interrupt context, which is not valid use in NuttX. This change copies the mixer into the buffer and runs the mixer management section of the code outside of interrupt context in the normal task.
The function `mission_item_to_position_setpoint()` is called in
`FollowTarget::update_position_sp()`. The nav_cmd is a
NAV_CMD_DO_FOLLOW_REPOSITION as set earlier in `set_follow_target_item`.
Since `mission_item_to_position_setpointi` returns early because the item
presumably contains no position, the lat/lon of the mission_item are
not copied over to the position_setpoint and therefore the vehicle will
never move in follow me position mode.
When checking a mission, the takeoff altitude is being checked
against the waypoint acceptance radius to ensure the MAV being
clear from ground before heading to the next waypoint.
However, until now the _horizontal_ acceptance radius was being
used, instead of the altitude reference value.
Targets PX4/Firmware/#7379
The TECS controller belongs really into the ECL (estimation & control library) where we have collected a number of vehicle control systems. It is being replaced by a new implementation of the algorithm, contributed by Paul Riseborough.
Instead of just checking whether the first waypoint is too far away from
home it makes sense to also check between waypoints.
This can prevent
- flyaways due to user errors, or
- catch the corner case where a takeoff waypoint is added to a mission
and therefore the first waypoint is not too far away, however, the
subsequent waypoints are still too far away.
Lorenz Meier