From 1018dec2468d2aa6f1b1961d8b7ae62911c821c2 Mon Sep 17 00:00:00 2001 From: Lorenz Meier Date: Sun, 22 Jun 2014 16:51:02 +0200 Subject: estimator: Get offsets under control, prepare GPS acceleration based initialization, but do not activate it yet --- .../ekf_att_pos_estimator_main.cpp | 34 +++++++++++++++++----- 1 file changed, 27 insertions(+), 7 deletions(-) (limited to 'src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp') diff --git a/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp b/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp index d8dbb1fe3..cb29b913c 100644 --- a/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp +++ b/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp @@ -188,7 +188,8 @@ private: struct map_projection_reference_s _pos_ref; float _baro_ref; /**< barometer reference altitude */ - float _baro_gps_offset; /**< offset between GPS and baro */ + float _baro_ref_offset; /**< offset between initial baro reference and GPS init baro altitude */ + float _baro_gps_offset; /**< offset between baro altitude (at GPS init time) and GPS altitude */ perf_counter_t _loop_perf; ///< loop performance counter perf_counter_t _perf_gyro; ///states[9]; // this should become zero in the local frame + _baro_gps_offset = _baro.altitude - gps_alt; _ekf->baroHgt = _baro.altitude; _ekf->hgtMea = 1.0f * (_ekf->baroHgt - (_baro_ref)); @@ -1159,7 +1164,7 @@ FixedwingEstimator::task_main() #if 0 warnx("HOME/REF: LA %8.4f,LO %8.4f,ALT %8.2f V: %8.4f %8.4f %8.4f", lat, lon, (double)gps_alt, (double)_ekf->velNED[0], (double)_ekf->velNED[1], (double)_ekf->velNED[2]); - warnx("BARO: %8.4f m / ref: %8.4f m / gps offs: %8.4f m", (double)_ekf->baroHgt, (double)_baro_ref, (double)_baro_gps_offset); + warnx("BARO: %8.4f m / ref: %8.4f m / gps offs: %8.4f m", (double)_ekf->baroHgt, (double)_baro_ref, (double)_baro_ref_offset); warnx("GPS: eph: %8.4f, epv: %8.4f, declination: %8.4f", (double)_gps.eph, (double)_gps.epv, (double)math::degrees(declination)); #endif @@ -1174,6 +1179,7 @@ FixedwingEstimator::task_main() _ekf->posNE[1] = posNED[1]; _local_pos.ref_alt = _baro_ref; + _baro_ref_offset = 0.0f; _baro_gps_offset = 0.0f; _ekf->InitialiseFilter(initVelNED, 0.0, 0.0, 0.0f, 0.0f); @@ -1229,6 +1235,19 @@ FixedwingEstimator::task_main() // Fuse GPS Measurements if (newDataGps && _gps_initialized) { // Convert GPS measurements to Pos NE, hgt and Vel NED + + float gps_dt = (_gps.timestamp_position - last_gps) / 1e6f; + + // Calculate acceleration predicted by GPS velocity change + if ((_ekf->velNED[0] != _gps.vel_n_m_s || + _ekf->velNED[1] != _gps.vel_e_m_s || + _ekf->velNED[2] != _gps.vel_d_m_s) && (gps_dt > 0.00001f)) { + + _ekf->accelGPSNED[0] = (_ekf->velNED[0] - _gps.vel_n_m_s) / gps_dt; + _ekf->accelGPSNED[1] = (_ekf->velNED[1] - _gps.vel_e_m_s) / gps_dt; + _ekf->accelGPSNED[2] = (_ekf->velNED[2] - _gps.vel_d_m_s) / gps_dt; + } + _ekf->velNED[0] = _gps.vel_n_m_s; _ekf->velNED[1] = _gps.vel_e_m_s; _ekf->velNED[2] = _gps.vel_d_m_s; @@ -1349,7 +1368,7 @@ FixedwingEstimator::task_main() _local_pos.x = _ekf->states[7]; _local_pos.y = _ekf->states[8]; // XXX need to announce change of Z reference somehow elegantly - _local_pos.z = _ekf->states[9] - _baro_gps_offset; + _local_pos.z = _ekf->states[9] - _baro_ref_offset; _local_pos.vx = _ekf->states[4]; _local_pos.vy = _ekf->states[5]; @@ -1411,7 +1430,7 @@ FixedwingEstimator::task_main() } /* local pos alt is negative, change sign and add alt offsets */ - _global_pos.alt = _local_pos.ref_alt + _baro_gps_offset + (-_local_pos.z); + _global_pos.alt = _baro_ref + (-_local_pos.z) - _baro_gps_offset; if (_local_pos.v_z_valid) { _global_pos.vel_d = _local_pos.vz; @@ -1513,7 +1532,8 @@ FixedwingEstimator::print_status() // 19-21: Body Magnetic Field Vector - gauss (X,Y,Z) printf("dtIMU: %8.6f IMUmsec: %d\n", (double)_ekf->dtIMU, (int)IMUmsec); - printf("ref alt: %8.6f\n", (double)_local_pos.ref_alt); + printf("baro alt: %8.4f GPS alt: %8.4f\n", (double)_baro.altitude, (double)(_gps.alt / 1e3f)); + printf("ref alt: %8.4f baro ref offset: %8.4f baro GPS offset: %8.4f\n", (double)_baro_ref, (double)_baro_ref_offset, (double)_baro_gps_offset); printf("dvel: %8.6f %8.6f %8.6f accel: %8.6f %8.6f %8.6f\n", (double)_ekf->dVelIMU.x, (double)_ekf->dVelIMU.y, (double)_ekf->dVelIMU.z, (double)_ekf->accel.x, (double)_ekf->accel.y, (double)_ekf->accel.z); printf("dang: %8.4f %8.4f %8.4f dang corr: %8.4f %8.4f %8.4f\n" , (double)_ekf->dAngIMU.x, (double)_ekf->dAngIMU.y, (double)_ekf->dAngIMU.z, (double)_ekf->correctedDelAng.x, (double)_ekf->correctedDelAng.y, (double)_ekf->correctedDelAng.z); printf("states (quat) [0-3]: %8.4f, %8.4f, %8.4f, %8.4f\n", (double)_ekf->states[0], (double)_ekf->states[1], (double)_ekf->states[2], (double)_ekf->states[3]); -- cgit v1.2.3