Merge pull request #204 from PX4/pr-gpsReset

ekf reset: more granular reset / timeout strategy for gps fusion
This commit is contained in:
Paul Riseborough
2016-10-26 06:52:10 +11:00
committed by GitHub
2 changed files with 32 additions and 20 deletions
+5
View File
@@ -261,6 +261,9 @@ struct parameters {
float vel_Tau; // velocity state correction time constant (1/sec)
float pos_Tau; // postion state correction time constant (1/sec)
unsigned no_gps_timeout_max; // maximum time we allow dead reckoning while both gps position and velocity measurements are being
// rejected
// Initialize parameter values. Initialization must be accomplished in the constructor to allow C99 compiler compatibility.
parameters()
{
@@ -351,6 +354,8 @@ struct parameters {
vel_Tau = 0.25f;
pos_Tau = 0.25f;
no_gps_timeout_max = 7e6; // maximum seven seconds of dead reckoning time for gps
}
};
+27 -20
View File
@@ -353,30 +353,24 @@ void Ekf::controlGpsFusion()
}
// handle the case when we are relying on GPS fusion and lose it
// handle the case when we now have GPS, but have not been using it for an extended period
if (_control_status.flags.gps && !_control_status.flags.opt_flow) {
// We are relying on GPS aiding to constrain attitude drift so after 10 seconds without aiding we need to do something
if ((_time_last_imu - _time_last_pos_fuse > 10e6) && (_time_last_imu - _time_last_vel_fuse > 10e6)) {
if (_time_last_imu - _time_last_gps > 5e5) {
// if we don't have gps then we need to switch to the non-aiding mode, zero the velocity states
// and set the synthetic GPS position to the current estimate
_control_status.flags.gps = false;
_last_known_posNE(0) = _state.pos(0);
_last_known_posNE(1) = _state.pos(1);
_state.vel.setZero();
ECL_WARN("EKF GPS fusion timout - stopping GPS aiding");
// We are relying on GPS aiding to constrain attitude drift so after 7 seconds without aiding we need to do something
bool do_reset = (_time_last_imu - _time_last_pos_fuse > _params.no_gps_timeout_max) && (_time_last_imu - _time_last_vel_fuse > _params.no_gps_timeout_max);
} else {
// Reset states to the last GPS measurement
resetPosition();
resetVelocity();
ECL_WARN("EKF GPS fusion timout - resetting to GPS");
// Our position measurments have been rejected for more than 14 seconds
do_reset |= _time_last_imu - _time_last_pos_fuse > 2 * _params.no_gps_timeout_max;
// Reset the timeout counters
_time_last_pos_fuse = _time_last_imu;
_time_last_vel_fuse = _time_last_imu;
if (do_reset) {
// Reset states to the last GPS measurement
resetPosition();
resetVelocity();
ECL_WARN("EKF GPS fusion timout - resetting to GPS");
// Reset the timeout counters
_time_last_pos_fuse = _time_last_imu;
_time_last_vel_fuse = _time_last_imu;
}
}
}
@@ -409,6 +403,19 @@ void Ekf::controlGpsFusion()
_control_status.flags.ev_hgt = false;
_fuse_height = true;
}
} else {
// handle the case where we do not have GPS and have not been using it for an extended period
if ((_time_last_imu - _time_last_gps > 10e6) && (_time_last_imu - _time_last_airspeed > 1e6) && (_time_last_imu - _time_last_optflow > 1e6)) {
// if we don't have a source of aiding to constrain attitude drift,
// then we need to switch to the non-aiding mode, zero the velocity states
// and set the synthetic GPS position to the current estimate
_control_status.flags.gps = false;
_last_known_posNE(0) = _state.pos(0);
_last_known_posNE(1) = _state.pos(1);
_state.vel.setZero();
ECL_WARN("EKF GPS fusion timout - stopping GPS aiding");
}
}
}