mc_pos_control: always require takeoff setpoint

Problem: The drone started taking off in LOITER (HOLD) mode even if on
ground and did not do a proper takeoff jump. The effect was mostly a
hovering close above ground or tilting/flipping because of integrator
wind-up.

Solution: Stay at minimum throttle until a takeoff setpoint is issued.
This commit is contained in:
Julian Oes
2016-12-15 10:17:03 +01:00
committed by Lorenz Meier
parent c64b8c7095
commit 65b8bcae12
@@ -1825,9 +1825,20 @@ MulticopterPositionControl::control_position(float dt)
float vel_z_change = (_vel(2) - _vel_prev(2)) / dt;
_acc_z_lp = _acc_z_lp * (1.0f - dt * 8.0f) + dt * 8.0f * vel_z_change;
/* adjust limits for landing mode */
if (!_control_mode.flag_control_manual_enabled && _pos_sp_triplet.current.valid &&
_pos_sp_triplet.current.type == position_setpoint_s::SETPOINT_TYPE_LAND) {
// We can only run the control if we're already in-air or have a takeoff setpoint.
// Otherwise, we should just bail out
const bool got_takeoff_setpoint = (_pos_sp_triplet.current.valid &&
_pos_sp_triplet.current.type == position_setpoint_s::SETPOINT_TYPE_TAKEOFF);
if (_vehicle_land_detected.landed && !got_takeoff_setpoint) {
PX4_INFO("still on ground");
// Keep throttle low while still on ground.
thr_max = 0.0f;
} else if (!_control_mode.flag_control_manual_enabled && _pos_sp_triplet.current.valid &&
_pos_sp_triplet.current.type == position_setpoint_s::SETPOINT_TYPE_LAND) {
/* adjust limits for landing mode */
/* limit max tilt and min lift when landing */
tilt_max = _params.tilt_max_land;