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author | Thomas Gubler <thomasgubler@gmail.com> | 2013-11-01 14:37:29 +0100 |
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committer | Thomas Gubler <thomasgubler@gmail.com> | 2013-11-01 14:37:29 +0100 |
commit | 116ee348a228481512965778f444dd1c5f373939 (patch) | |
tree | 1c8eac32f87d2e0235ba4f4834ca3012cfb08c87 /src/modules/fw_pos_control_l1 | |
parent | a6b85cfbf76dbe0e829e503a09660ffb11f003d0 (diff) | |
download | px4-firmware-116ee348a228481512965778f444dd1c5f373939.tar.gz px4-firmware-116ee348a228481512965778f444dd1c5f373939.tar.bz2 px4-firmware-116ee348a228481512965778f444dd1c5f373939.zip |
landing: make altitude handling before helper waypoint L more clever
Diffstat (limited to 'src/modules/fw_pos_control_l1')
-rw-r--r-- | src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp b/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp index a68de4525..a90899528 100644 --- a/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp +++ b/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp @@ -280,6 +280,11 @@ private: void vehicle_setpoint_poll(); /** + * Get Altitude on the landing glide slope + */ + float getLandingSlopeAbsoluteAltitude(float wp_distance, float wp_altitude, float landing_slope_angle_rad); + + /** * Control position. */ bool control_position(const math::Vector2f &global_pos, const math::Vector2f &ground_speed, @@ -624,6 +629,11 @@ FixedwingPositionControl::calculate_gndspeed_undershoot() } } +float FixedwingPositionControl::getLandingSlopeAbsoluteAltitude(float wp_distance, float wp_altitude, float landing_slope_angle_rad) +{ + return wp_distance * tanf(landing_slope_angle_rad) + wp_altitude; +} + bool FixedwingPositionControl::control_position(const math::Vector2f ¤t_position, const math::Vector2f &ground_speed, const struct vehicle_global_position_set_triplet_s &global_triplet) @@ -778,7 +788,10 @@ FixedwingPositionControl::control_position(const math::Vector2f ¤t_positio float airspeed_approach = (_parameters.airspeed_min + _parameters.airspeed_trim) / 2.0f; const float landing_slope_angle_rad = 20.0f/180.0f*M_PI_F; //xxx: param - float landing_slope_alt_desired = wp_distance * tanf(landing_slope_angle_rad) + _global_triplet.current.altitude; + const float landingslope_length = 64.0f; + const float L_wp_distance = cosf(landing_slope_angle_rad) * landingslope_length; + float L_altitude = getLandingSlopeAbsoluteAltitude(L_wp_distance, _global_triplet.current.altitude, landing_slope_angle_rad); + float landing_slope_alt_desired = getLandingSlopeAbsoluteAltitude(wp_distance, _global_triplet.current.altitude, landing_slope_angle_rad); if (altitude_error > -4.0f) { @@ -799,7 +812,7 @@ FixedwingPositionControl::control_position(const math::Vector2f ¤t_positio /* limit roll motion to prevent wings from touching the ground first */ _att_sp.roll_body = math::constrain(_att_sp.roll_body, math::radians(-10.0f), math::radians(10.0f)); - } else if (wp_distance < 60.0f || altitude_error > -20.0f) { + } else if (wp_distance < L_wp_distance) { /* minimize speed to approach speed, stay on glide slope */ _tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, landing_slope_alt_desired, calculate_target_airspeed(airspeed_approach), @@ -811,10 +824,20 @@ FixedwingPositionControl::control_position(const math::Vector2f ¤t_positio } else { /* normal cruise speed - * intersect glide slope: if current position higher than slope sink to glide slope but continue horizontally if below slope */ + * intersect glide slope: + * if current position is higher or within 10m of slope follow the glide slope + * if current position is below slope -10m and above altitude at L (see documentation) continue horizontally + * if current position is below altitude at L, climb to altitude of L */ float altitude_desired = _global_pos.alt; - if (_global_pos.alt > landing_slope_alt_desired) { + if (_global_pos.alt > landing_slope_alt_desired - 10.0f) { + /* stay on slope */ altitude_desired = landing_slope_alt_desired; + } else if (_global_pos.alt < landing_slope_alt_desired - 10.0f && _global_pos.alt > L_altitude) { + /* continue horizontally */ + altitude_desired = _global_pos.alt; //xxx: dangerous, but we have the altitude < L_altitude protection + } else { + /* climb to L_altitude */ + altitude_desired = L_altitude; } _tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, altitude_desired, calculate_target_airspeed(_parameters.airspeed_trim), |