From 95aba0d70eae6a9aba55d31f223b852df1f82dcb Mon Sep 17 00:00:00 2001 From: Lorenz Meier Date: Thu, 17 Oct 2013 09:36:20 +0200 Subject: Almost perfect landing approach, needs touch-down fine tuning --- .../fw_pos_control_l1/fw_pos_control_l1_main.cpp | 47 +++++++++++++++++----- src/modules/mavlink/waypoints.c | 37 +++++++++++------ 2 files changed, 62 insertions(+), 22 deletions(-) (limited to 'src') 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 348a17ba6..219c6ffa6 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 @@ -635,6 +635,9 @@ FixedwingPositionControl::control_position(const math::Vector2f ¤t_positio /* no throttle limit as default */ float throttle_max = 1.0f; + /* not in non-abort mode for landing yet */ + bool land_noreturn = false; + /* AUTONOMOUS FLIGHT */ // XXX this should only execute if auto AND safety off (actuators active), @@ -717,23 +720,39 @@ FixedwingPositionControl::control_position(const math::Vector2f ¤t_positio } else if (global_triplet.current.nav_cmd == NAV_CMD_LAND) { - _l1_control.navigate_waypoints(prev_wp, next_wp, current_position, ground_speed); + /* switch to heading hold for the last meters, continue heading hold after */ + + float wp_distance = get_distance_to_next_waypoint(current_position.getX(), current_position.getY(), next_wp.getX(), next_wp.getY()); + + if (wp_distance < 5.0f || land_noreturn) { + + /* heading hold, along the line connecting this and the last waypoint */ + float target_bearing = get_bearing_to_next_waypoint(prev_wp.getX(), prev_wp.getY(), next_wp.getX(), next_wp.getY()); + _l1_control.navigate_heading(target_bearing, _att.yaw, ground_speed); + + if (altitude_error > -20.0f) + land_noreturn = true; + + } else { + + /* normal navigation */ + _l1_control.navigate_waypoints(prev_wp, next_wp, current_position, ground_speed); + } + _att_sp.roll_body = _l1_control.nav_roll(); _att_sp.yaw_body = _l1_control.nav_bearing(); /* apply minimum pitch (flare) and limit roll if close to touch down, altitude error is negative (going down) */ // XXX this could make a great param - if (altitude_error > -10.0f) { - - float flare_angle_rad = math::radians(10.0f);//math::radians(global_triplet.current.param1) - float land_pitch_min = math::radians(5.0f); - float throttle_land = _parameters.throttle_min + (_parameters.throttle_max - _parameters.throttle_min) * 0.1f; + float flare_angle_rad = math::radians(10.0f);//math::radians(global_triplet.current.param1) + float land_pitch_min = math::radians(5.0f); + float throttle_land = _parameters.throttle_min + (_parameters.throttle_max - _parameters.throttle_min) * 0.1f; + float airspeed_land = (_parameters.airspeed_min + _parameters.airspeed_trim) / 2.0f; - // /* set the speed weight to 0.0 to push the system to control altitude with pitch */ - // _tecs.set_speed_weight(0.0f); + if (altitude_error > -5.0f) { - _tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, _parameters.airspeed_min, + _tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_min), _airspeed.indicated_airspeed_m_s, eas2tas, false, flare_angle_rad, 0.0f, _parameters.throttle_max, throttle_land, @@ -743,7 +762,15 @@ FixedwingPositionControl::control_position(const math::Vector2f ¤t_positio throttle_max = math::min(throttle_max, _parameters.throttle_land_max); /* limit roll motion to prevent wings from touching the ground first */ - _att_sp.roll_body = math::constrain(_att_sp.roll_body, math::radians(-20.0f), math::radians(20.0f)); + _att_sp.roll_body = math::constrain(_att_sp.roll_body, math::radians(-10.0f), math::radians(10.0f)); + + } else if (altitude_error > -20.0f) { + + _tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(airspeed_land), + _airspeed.indicated_airspeed_m_s, eas2tas, + false, flare_angle_rad, + _parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise, + math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max)); } else { diff --git a/src/modules/mavlink/waypoints.c b/src/modules/mavlink/waypoints.c index ddad5f0df..adaf81404 100644 --- a/src/modules/mavlink/waypoints.c +++ b/src/modules/mavlink/waypoints.c @@ -399,6 +399,13 @@ void check_waypoints_reached(uint64_t now, const struct vehicle_global_position_ if (time_elapsed) { if (cur_wp->autocontinue) { + + /* safeguard against invalid missions with last wp autocontinue on */ + if (wpm->current_active_wp_id == wpm->size - 1) { + /* stop handling missions here */ + cur_wp->autocontinue = false; + } + cur_wp->current = 0; float navigation_lat = -1.0f; @@ -419,13 +426,16 @@ void check_waypoints_reached(uint64_t now, const struct vehicle_global_position_ navigation_frame = MAV_FRAME_LOCAL_NED; } + /* guard against missions without final land waypoint */ /* only accept supported navigation waypoints, skip unknown ones */ do { + /* pick up the last valid navigation waypoint, this will be one we hold on to after the mission */ if (wpm->waypoints[wpm->current_active_wp_id].command == (int)MAV_CMD_NAV_WAYPOINT || wpm->waypoints[wpm->current_active_wp_id].command == (int)MAV_CMD_NAV_LOITER_TURNS || wpm->waypoints[wpm->current_active_wp_id].command == (int)MAV_CMD_NAV_LOITER_TIME || - wpm->waypoints[wpm->current_active_wp_id].command == (int)MAV_CMD_NAV_LOITER_UNLIM) { + wpm->waypoints[wpm->current_active_wp_id].command == (int)MAV_CMD_NAV_LOITER_UNLIM || + wpm->waypoints[wpm->current_active_wp_id].command == (int)MAV_CMD_NAV_TAKEOFF) { /* this is a navigation waypoint */ navigation_frame = cur_wp->frame; @@ -434,17 +444,20 @@ void check_waypoints_reached(uint64_t now, const struct vehicle_global_position_ navigation_alt = cur_wp->z; } - if (wpm->current_active_wp_id == wpm->size - 1 && wpm->size > 1) { - /* the last waypoint was reached, if auto continue is - * activated keep the system loitering there. - */ - cur_wp->command = MAV_CMD_NAV_LOITER_UNLIM; - cur_wp->param3 = 20.0f; // XXX magic number 20 m loiter radius - cur_wp->frame = navigation_frame; - cur_wp->x = navigation_lat; - cur_wp->y = navigation_lon; - cur_wp->z = navigation_alt; - cur_wp->autocontinue = false; + if (wpm->current_active_wp_id == wpm->size - 1) { + + /* if we're not landing at the last nav waypoint, we're falling back to loiter */ + if (wpm->waypoints[wpm->current_active_wp_id].command != (int)MAV_CMD_NAV_LAND) { + /* the last waypoint was reached, if auto continue is + * activated AND it is NOT a land waypoint, keep the system loitering there. + */ + cur_wp->command = MAV_CMD_NAV_LOITER_UNLIM; + cur_wp->param3 = 20.0f; // XXX magic number 20 m loiter radius + cur_wp->frame = navigation_frame; + cur_wp->x = navigation_lat; + cur_wp->y = navigation_lon; + cur_wp->z = navigation_alt; + } /* we risk an endless loop for missions without navigation waypoints, abort. */ break; -- cgit v1.2.3