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landdetector groundcontact: adjust climbrate if landing speed is low

This commit is contained in:
Dennis Mannhart 2017-07-26 10:54:47 +02:00 committed by Lorenz Meier
parent a9b12cc8b4
commit e39b38ba96
1 changed files with 22 additions and 13 deletions
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35
src/modules/land_detector/MulticopterLandDetector.cpp
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@ -192,29 +192,38 @@ bool MulticopterLandDetector::_get_ground_contact_state()
const bool manual_control_idle = (_has_manual_control_present() && _manual.z < _params.manual_stick_down_threshold);
const bool manual_control_idle_or_auto = manual_control_idle || !_control_mode.flag_control_manual_enabled;
// Widen acceptance thresholds for landed state right after landed
// so that motor spool-up and other effects do not trigger false negatives.
float landThresholdFactor = 1.0f;
if (hrt_elapsed_time(&_landed_time) < LAND_DETECTOR_LAND_PHASE_TIME_US) {
landThresholdFactor = 2.5f;
}
// land speed threshold
float land_speed_threshold = 0.9f * math::max(_params.landSpeed, 0.1f);
// Check if we are moving vertically - this might see a spike after arming due to
// throttle-up vibration. If accelerating fast the throttle thresholds will still give
// an accurate in-air indication.
bool verticalMovement = fabsf(_vehicleLocalPosition.vz) > _params.maxClimbRate * landThresholdFactor;
bool verticalMovement;
// if we have a valid velocity setpoint and the vehicle is demanded to go down but no vertical movement present,
// we then can assume that the vehicle hit ground
bool in_descend = _is_climb_rate_enabled()
&& (_vehicleLocalPositionSetpoint.vz >= 0.9f * math::max(_params.landSpeed, 0.1f));
bool hit_ground = in_descend && !verticalMovement;
if (hrt_elapsed_time(&_landed_time) < LAND_DETECTOR_LAND_PHASE_TIME_US) {
// Widen acceptance thresholds for landed state right after arming
// so that motor spool-up and other effects do not trigger false negatives.
verticalMovement = fabsf(_vehicleLocalPosition.vz) > _params.maxClimbRate * 2.5f;
} else {
// Adjust maxClimbRate if land_speed is lower than 2x maxClimbrate
float maxClimbRate = ((land_speed_threshold * 0.5f) < _params.maxClimbRate) ? (0.5f * land_speed_threshold) :
_params.maxClimbRate;
verticalMovement = fabsf(_vehicleLocalPosition.vz) > maxClimbRate;
}
// Check if we are moving horizontally.
bool horizontalMovement = sqrtf(_vehicleLocalPosition.vx * _vehicleLocalPosition.vx
+ _vehicleLocalPosition.vy * _vehicleLocalPosition.vy) > _params.maxVelocity;
// if we have a valid velocity setpoint and the vehicle is demanded to go down but no vertical movement present,
// we then can assume that the vehicle hit ground
bool in_descend = _is_climb_rate_enabled()
&& (_vehicleLocalPositionSetpoint.vz >= land_speed_threshold);
bool hit_ground = in_descend && !verticalMovement;
// If pilots commands down or in auto mode and we are already below minimal thrust and we do not move down we assume ground contact
// TODO: we need an accelerometer based check for vertical movement for flying without GPS
if (manual_control_idle_or_auto && (_has_low_thrust() || hit_ground) && (!horizontalMovement || !_has_position_lock())