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FW LandDetector: disregard horizontal velocity if local_position.v_xy_valid is false #24133

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38 changes: 30 additions & 8 deletions src/modules/land_detector/FixedwingLandDetector.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -71,9 +71,18 @@ bool FixedwingLandDetector::_get_landed_state()

} else if (hrt_elapsed_time(&_vehicle_local_position.timestamp) < 1_s) {

// Horizontal velocity complimentary filter.
float val = 0.97f * _velocity_xy_filtered + 0.03f * sqrtf(_vehicle_local_position.vx * _vehicle_local_position.vx +
_vehicle_local_position.vy * _vehicle_local_position.vy);
float val;

if (!_vehicle_local_position.v_xy_valid) {
// set _velocity_xy_filtered to 0 if data is invalid
val = 0.0f;
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} else {
// Horizontal velocity complimentary filter.
val = 0.97f * _velocity_xy_filtered + 0.03f * sqrtf(_vehicle_local_position.vx * _vehicle_local_position.vx +
_vehicle_local_position.vy * _vehicle_local_position.vy);
}


if (PX4_ISFINITE(val)) {
_velocity_xy_filtered = val;
Expand Down Expand Up @@ -105,15 +114,28 @@ bool FixedwingLandDetector::_get_landed_state()
const float acc_hor = matrix::Vector2f(_acceleration).norm();
_xy_accel_filtered = _xy_accel_filtered * 0.8f + acc_hor * 0.18f;

// Check for angular velocity (disregard yaw)
const float rot_vel_hor = _angular_velocity.xy().norm();
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Considering only rotations around x & y to be consistent with MC landing condition, but can be extended to all three axes if it makes sense in FW context.

val = _velocity_rot_filtered * 0.95f + rot_vel_hor * 0.05f;

if (PX4_ISFINITE(val)) {
_velocity_rot_filtered = val;
}

// make groundspeed threshold tighter if airspeed is invalid
const float vel_xy_max_threshold = airspeed_invalid ? 0.7f * _param_lndfw_vel_xy_max.get() :
const float vel_xy_max_threshold = airspeed_invalid ? 0.7f * _param_lndfw_vel_xy_max.get() :
_param_lndfw_vel_xy_max.get();

// make rotation threshold tighter if groundspeed is invalid
const float max_rotation_threshold = _vehicle_local_position.v_xy_valid ? math::radians(_param_lndfw_rot_max.get()) :
math::radians(_param_lndfw_rot_max.get()) * 0.5f;

// Crude land detector for fixedwing.
landDetected = _airspeed_filtered < _param_lndfw_airspd.get()
&& _velocity_xy_filtered < vel_xy_max_threshold
&& _velocity_z_filtered < _param_lndfw_vel_z_max.get()
&& _xy_accel_filtered < _param_lndfw_xyaccel_max.get();
landDetected = _airspeed_filtered < _param_lndfw_airspd.get()
&& _velocity_xy_filtered < vel_xy_max_threshold
&& _velocity_z_filtered < _param_lndfw_vel_z_max.get()
&& _xy_accel_filtered < _param_lndfw_xyaccel_max.get()
&& _velocity_rot_filtered < max_rotation_threshold;

} else {
// Control state topic has timed out and we need to assume we're landed.
Expand Down
2 changes: 2 additions & 0 deletions src/modules/land_detector/FixedwingLandDetector.h
Original file line number Diff line number Diff line change
Expand Up @@ -75,13 +75,15 @@ class FixedwingLandDetector final : public LandDetector
float _velocity_xy_filtered{0.0f};
float _velocity_z_filtered{0.0f};
float _xy_accel_filtered{0.0f};
float _velocity_rot_filtered{0.0f};

DEFINE_PARAMETERS_CUSTOM_PARENT(
LandDetector,
(ParamFloat<px4::params::LNDFW_XYACC_MAX>) _param_lndfw_xyaccel_max,
(ParamFloat<px4::params::LNDFW_AIRSPD_MAX>) _param_lndfw_airspd,
(ParamFloat<px4::params::LNDFW_VEL_XY_MAX>) _param_lndfw_vel_xy_max,
(ParamFloat<px4::params::LNDFW_VEL_Z_MAX>) _param_lndfw_vel_z_max,
(ParamFloat<px4::params::LNDFW_ROT_MAX>) _param_lndfw_rot_max,
(ParamFloat<px4::params::LNDFW_TRIG_TIME>) _param_lndfw_trig_time
);
};
Expand Down
11 changes: 11 additions & 0 deletions src/modules/land_detector/land_detector_params_fw.c
Original file line number Diff line number Diff line change
Expand Up @@ -102,3 +102,14 @@ PARAM_DEFINE_FLOAT(LNDFW_AIRSPD_MAX, 6.00f);
* @group Land Detector
*/
PARAM_DEFINE_FLOAT(LNDFW_TRIG_TIME, 2.f);

/**
* Fixed-wing land detector: max rotation
*
* Maximum allowed angular velocity around each axis allowed in the landed state.
*
* @unit deg/s
* @decimal 1
* @group Land Detector
*/
PARAM_DEFINE_FLOAT(LNDFW_ROT_MAX, 0.06f);
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