MulticopterLandDetector.cpp File Reference

The MC land-detector goes through 3 states before it will detect landed: More...

#include <math.h>
#include <mathlib/mathlib.h>
#include <matrix/math.hpp>
#include "MulticopterLandDetector.h"

Include dependency graph for MulticopterLandDetector.cpp:

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Namespaces
	land_detector

Detailed Description

The MC land-detector goes through 3 states before it will detect landed:

State 1 (=ground_contact): ground_contact is detected once the vehicle is not moving along the NED-z direction and has a thrust value below 0.3 of the thrust_range (thrust_hover - thrust_min). The condition has to be true for GROUND_CONTACT_TRIGGER_TIME_US in order to detect ground_contact

State 2 (=maybe_landed): maybe_landed can only occur if the internal ground_contact hysteresis state is true. maybe_landed criteria requires to have no motion in x and y, no rotation and a thrust below 0.1 of the thrust_range (thrust_hover - thrust_min). In addition, the mc_pos_control turns off the thrust_sp in body frame along x and y which helps to detect maybe_landed. The criteria for maybe_landed needs to be true for MAYBE_LAND_DETECTOR_TRIGGER_TIME_US.

State 3 (=landed) landed can only be detected if maybe_landed is true for LAND_DETECTOR_TRIGGER_TIME_US. No farther criteria is tested, but the mc_pos_control goes into idle (thrust_sp = 0) which helps to detect landed. By doing this the thrust-criteria of State 2 will always be met, however the remaining criteria of no rotation and no motion still have to be valid.

It is to note that if one criteria is not met, then vehicle exits the state directly without blocking.

If the land-detector does not detect ground_contact, then the vehicle is either flying or falling, where free fall detection heavily relies on the acceleration. TODO: verify that free fall is reliable

Author

Johan Jansen jnsn..nosp@m.joha.nosp@m.n@gma.nosp@m.il.c.nosp@m.om

Morten Lysgaard morte.nosp@m.n@ly.nosp@m.sgaar.nosp@m.d.no

Julian Oes julia.nosp@m.n@oe.nosp@m.s.ch

Definition in file MulticopterLandDetector.cpp.