EKF2.cpp 72.3 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952
/****************************************************************************
 *
 *   Copyright (c) 2015-2021 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

#include "EKF2.hpp"

using namespace time_literals;
using math::constrain;
using matrix::Eulerf;
using matrix::Quatf;
using matrix::Vector3f;

pthread_mutex_t ekf2_module_mutex = PTHREAD_MUTEX_INITIALIZER;
static px4::atomic<EKF2 *> _objects[EKF2_MAX_INSTANCES] {};
#if !defined(CONSTRAINED_FLASH)
static px4::atomic<EKF2Selector *> _ekf2_selector {nullptr};
#endif // !CONSTRAINED_FLASH

EKF2::EKF2(bool multi_mode, const px4::wq_config_t &config, bool replay_mode):
	ModuleParams(nullptr),
	ScheduledWorkItem(MODULE_NAME, config),
	_replay_mode(replay_mode && !multi_mode),
	_multi_mode(multi_mode),
	_instance(multi_mode ? -1 : 0),
	_attitude_pub(multi_mode ? ORB_ID(estimator_attitude) : ORB_ID(vehicle_attitude)),
	_local_position_pub(multi_mode ? ORB_ID(estimator_local_position) : ORB_ID(vehicle_local_position)),
	_global_position_pub(multi_mode ? ORB_ID(estimator_global_position) : ORB_ID(vehicle_global_position)),
	_odometry_pub(multi_mode ? ORB_ID(estimator_odometry) : ORB_ID(vehicle_odometry)),
	_wind_pub(multi_mode ? ORB_ID(estimator_wind) : ORB_ID(wind)),
	_params(_ekf.getParamHandle()),
	_param_ekf2_min_obs_dt(_params->sensor_interval_min_ms),
	_param_ekf2_mag_delay(_params->mag_delay_ms),
	_param_ekf2_baro_delay(_params->baro_delay_ms),
	_param_ekf2_gps_delay(_params->gps_delay_ms),
	_param_ekf2_of_delay(_params->flow_delay_ms),
	_param_ekf2_rng_delay(_params->range_delay_ms),
	_param_ekf2_asp_delay(_params->airspeed_delay_ms),
	_param_ekf2_ev_delay(_params->ev_delay_ms),
	_param_ekf2_avel_delay(_params->auxvel_delay_ms),
	_param_ekf2_gyr_noise(_params->gyro_noise),
	_param_ekf2_acc_noise(_params->accel_noise),
	_param_ekf2_gyr_b_noise(_params->gyro_bias_p_noise),
	_param_ekf2_acc_b_noise(_params->accel_bias_p_noise),
	_param_ekf2_mag_e_noise(_params->mage_p_noise),
	_param_ekf2_mag_b_noise(_params->magb_p_noise),
	_param_ekf2_wind_noise(_params->wind_vel_p_noise),
	_param_ekf2_terr_noise(_params->terrain_p_noise),
	_param_ekf2_terr_grad(_params->terrain_gradient),
	_param_ekf2_gps_v_noise(_params->gps_vel_noise),
	_param_ekf2_gps_p_noise(_params->gps_pos_noise),
	_param_ekf2_noaid_noise(_params->pos_noaid_noise),
	_param_ekf2_baro_noise(_params->baro_noise),
	_param_ekf2_baro_gate(_params->baro_innov_gate),
	_param_ekf2_gnd_eff_dz(_params->gnd_effect_deadzone),
	_param_ekf2_gnd_max_hgt(_params->gnd_effect_max_hgt),
	_param_ekf2_gps_p_gate(_params->gps_pos_innov_gate),
	_param_ekf2_gps_v_gate(_params->gps_vel_innov_gate),
	_param_ekf2_tas_gate(_params->tas_innov_gate),
	_param_ekf2_head_noise(_params->mag_heading_noise),
	_param_ekf2_mag_noise(_params->mag_noise),
	_param_ekf2_eas_noise(_params->eas_noise),
	_param_ekf2_beta_gate(_params->beta_innov_gate),
	_param_ekf2_beta_noise(_params->beta_noise),
	_param_ekf2_mag_decl(_params->mag_declination_deg),
	_param_ekf2_hdg_gate(_params->heading_innov_gate),
	_param_ekf2_mag_gate(_params->mag_innov_gate),
	_param_ekf2_decl_type(_params->mag_declination_source),
	_param_ekf2_mag_type(_params->mag_fusion_type),
	_param_ekf2_mag_acclim(_params->mag_acc_gate),
	_param_ekf2_mag_yawlim(_params->mag_yaw_rate_gate),
	_param_ekf2_gps_check(_params->gps_check_mask),
	_param_ekf2_req_eph(_params->req_hacc),
	_param_ekf2_req_epv(_params->req_vacc),
	_param_ekf2_req_sacc(_params->req_sacc),
	_param_ekf2_req_nsats(_params->req_nsats),
	_param_ekf2_req_pdop(_params->req_pdop),
	_param_ekf2_req_hdrift(_params->req_hdrift),
	_param_ekf2_req_vdrift(_params->req_vdrift),
	_param_ekf2_aid_mask(_params->fusion_mode),
	_param_ekf2_hgt_mode(_params->vdist_sensor_type),
	_param_ekf2_terr_mask(_params->terrain_fusion_mode),
	_param_ekf2_noaid_tout(_params->valid_timeout_max),
	_param_ekf2_rng_noise(_params->range_noise),
	_param_ekf2_rng_sfe(_params->range_noise_scaler),
	_param_ekf2_rng_gate(_params->range_innov_gate),
	_param_ekf2_min_rng(_params->rng_gnd_clearance),
	_param_ekf2_rng_pitch(_params->rng_sens_pitch),
	_param_ekf2_rng_aid(_params->range_aid),
	_param_ekf2_rng_a_vmax(_params->max_vel_for_range_aid),
	_param_ekf2_rng_a_hmax(_params->max_hagl_for_range_aid),
	_param_ekf2_rng_a_igate(_params->range_aid_innov_gate),
	_param_ekf2_rng_qlty_t(_params->range_valid_quality_s),
	_param_ekf2_evv_gate(_params->ev_vel_innov_gate),
	_param_ekf2_evp_gate(_params->ev_pos_innov_gate),
	_param_ekf2_of_n_min(_params->flow_noise),
	_param_ekf2_of_n_max(_params->flow_noise_qual_min),
	_param_ekf2_of_qmin(_params->flow_qual_min),
	_param_ekf2_of_gate(_params->flow_innov_gate),
	_param_ekf2_imu_pos_x(_params->imu_pos_body(0)),
	_param_ekf2_imu_pos_y(_params->imu_pos_body(1)),
	_param_ekf2_imu_pos_z(_params->imu_pos_body(2)),
	_param_ekf2_gps_pos_x(_params->gps_pos_body(0)),
	_param_ekf2_gps_pos_y(_params->gps_pos_body(1)),
	_param_ekf2_gps_pos_z(_params->gps_pos_body(2)),
	_param_ekf2_rng_pos_x(_params->rng_pos_body(0)),
	_param_ekf2_rng_pos_y(_params->rng_pos_body(1)),
	_param_ekf2_rng_pos_z(_params->rng_pos_body(2)),
	_param_ekf2_of_pos_x(_params->flow_pos_body(0)),
	_param_ekf2_of_pos_y(_params->flow_pos_body(1)),
	_param_ekf2_of_pos_z(_params->flow_pos_body(2)),
	_param_ekf2_ev_pos_x(_params->ev_pos_body(0)),
	_param_ekf2_ev_pos_y(_params->ev_pos_body(1)),
	_param_ekf2_ev_pos_z(_params->ev_pos_body(2)),
	_param_ekf2_tau_vel(_params->vel_Tau),
	_param_ekf2_tau_pos(_params->pos_Tau),
	_param_ekf2_gbias_init(_params->switch_on_gyro_bias),
	_param_ekf2_abias_init(_params->switch_on_accel_bias),
	_param_ekf2_angerr_init(_params->initial_tilt_err),
	_param_ekf2_abl_lim(_params->acc_bias_lim),
	_param_ekf2_abl_acclim(_params->acc_bias_learn_acc_lim),
	_param_ekf2_abl_gyrlim(_params->acc_bias_learn_gyr_lim),
	_param_ekf2_abl_tau(_params->acc_bias_learn_tc),
	_param_ekf2_drag_noise(_params->drag_noise),
	_param_ekf2_bcoef_x(_params->bcoef_x),
	_param_ekf2_bcoef_y(_params->bcoef_y),
	_param_ekf2_aspd_max(_params->max_correction_airspeed),
	_param_ekf2_pcoef_xp(_params->static_pressure_coef_xp),
	_param_ekf2_pcoef_xn(_params->static_pressure_coef_xn),
	_param_ekf2_pcoef_yp(_params->static_pressure_coef_yp),
	_param_ekf2_pcoef_yn(_params->static_pressure_coef_yn),
	_param_ekf2_pcoef_z(_params->static_pressure_coef_z),
	_param_ekf2_move_test(_params->is_moving_scaler),
	_param_ekf2_mag_check(_params->check_mag_strength),
	_param_ekf2_synthetic_mag_z(_params->synthesize_mag_z),
	_param_ekf2_gsf_tas_default(_params->EKFGSF_tas_default)
{
}

EKF2::~EKF2()
{
	perf_free(_ecl_ekf_update_perf);
	perf_free(_ecl_ekf_update_full_perf);
	perf_free(_imu_missed_perf);
}

bool EKF2::multi_init(int imu, int mag)
{
	// advertise immediately to ensure consistent uORB instance numbering
	_attitude_pub.advertise();
	_local_position_pub.advertise();
	_global_position_pub.advertise();
	_odometry_pub.advertise();
	_wind_pub.advertise();

	_ekf2_timestamps_pub.advertise();
	_ekf_gps_drift_pub.advertise();
	_estimator_innovation_test_ratios_pub.advertise();
	_estimator_innovation_variances_pub.advertise();
	_estimator_innovations_pub.advertise();
	_estimator_optical_flow_vel_pub.advertise();
	_estimator_sensor_bias_pub.advertise();
	_estimator_states_pub.advertise();
	_estimator_status_pub.advertise();
	_estimator_status_flags_pub.advertise();
	_estimator_visual_odometry_aligned_pub.advertised();
	_yaw_est_pub.advertise();

	_vehicle_imu_sub.ChangeInstance(imu);
	_magnetometer_sub.ChangeInstance(mag);

	const int status_instance = _estimator_states_pub.get_instance();

	if ((status_instance >= 0)
	    && (_attitude_pub.get_instance() == status_instance)
	    && (_local_position_pub.get_instance() == status_instance)
	    && (_global_position_pub.get_instance() == status_instance)) {

		_instance = status_instance;
		return true;
	}

	PX4_ERR("publication instance problem: %d att: %d lpos: %d gpos: %d", status_instance,
		_attitude_pub.get_instance(), _local_position_pub.get_instance(), _global_position_pub.get_instance());

	return false;
}

int EKF2::print_status()
{
	PX4_INFO_RAW("ekf2:%d attitude: %d, local position: %d, global position: %d\n", _instance, _ekf.attitude_valid(),
		     _ekf.local_position_is_valid(), _ekf.global_position_is_valid());
	perf_print_counter(_ecl_ekf_update_perf);
	perf_print_counter(_ecl_ekf_update_full_perf);
	perf_print_counter(_imu_missed_perf);
	return 0;
}

void EKF2::Run()
{
	if (should_exit()) {
		_sensor_combined_sub.unregisterCallback();
		_vehicle_imu_sub.unregisterCallback();

		return;
	}

	// check for parameter updates
	if (_parameter_update_sub.updated() || !_callback_registered) {
		// clear update
		parameter_update_s pupdate;
		_parameter_update_sub.copy(&pupdate);

		// update parameters from storage
		updateParams();

		_ekf.set_min_required_gps_health_time(_param_ekf2_req_gps_h.get() * 1_s);

		// The airspeed scale factor correcton is only available via parameter as used by the airspeed module
		param_t param_aspd_scale = param_find("ASPD_SCALE");

		if (param_aspd_scale != PARAM_INVALID) {
			param_get(param_aspd_scale, &_airspeed_scale_factor);
		}
	}

	if (!_callback_registered) {
		if (_multi_mode) {
			_callback_registered = _vehicle_imu_sub.registerCallback();

		} else {
			_callback_registered = _sensor_combined_sub.registerCallback();
		}

		if (!_callback_registered) {
			PX4_WARN("%d - failed to register callback, retrying", _instance);
			ScheduleDelayed(1_s);
			return;
		}
	}

	if (_vehicle_command_sub.updated()) {
		vehicle_command_s vehicle_command;

		if (_vehicle_command_sub.update(&vehicle_command)) {
			if (vehicle_command.command == vehicle_command_s::VEHICLE_CMD_SET_GPS_GLOBAL_ORIGIN) {
				if (!_ekf.control_status_flags().in_air) {

					uint64_t origin_time {};
					double latitude = vehicle_command.param5;
					double longitude = vehicle_command.param6;
					float altitude = vehicle_command.param7;

					_ekf.setEkfGlobalOrigin(latitude, longitude, altitude);

					// Validate the ekf origin status.
					_ekf.getEkfGlobalOrigin(origin_time, latitude, longitude, altitude);
					PX4_INFO("New NED origin (LLA): %3.10f, %3.10f, %4.3f\n", latitude, longitude, static_cast<double>(altitude));
				}
			}
		}
	}

	bool imu_updated = false;
	imuSample imu_sample_new {};

	hrt_abstime imu_dt = 0; // for tracking time slip later

	if (_multi_mode) {
		const unsigned last_generation = _vehicle_imu_sub.get_last_generation();
		vehicle_imu_s imu;
		imu_updated = _vehicle_imu_sub.update(&imu);

		if (imu_updated && (_vehicle_imu_sub.get_last_generation() != last_generation + 1)) {
			perf_count(_imu_missed_perf);
			PX4_DEBUG("%d - vehicle_imu lost, generation %d -> %d", _instance, last_generation,
				  _vehicle_imu_sub.get_last_generation());
		}

		imu_sample_new.time_us = imu.timestamp_sample;
		imu_sample_new.delta_ang_dt = imu.delta_angle_dt * 1.e-6f;
		imu_sample_new.delta_ang = Vector3f{imu.delta_angle};
		imu_sample_new.delta_vel_dt = imu.delta_velocity_dt * 1.e-6f;
		imu_sample_new.delta_vel = Vector3f{imu.delta_velocity};

		if (imu.delta_velocity_clipping > 0) {
			imu_sample_new.delta_vel_clipping[0] = imu.delta_velocity_clipping & vehicle_imu_s::CLIPPING_X;
			imu_sample_new.delta_vel_clipping[1] = imu.delta_velocity_clipping & vehicle_imu_s::CLIPPING_Y;
			imu_sample_new.delta_vel_clipping[2] = imu.delta_velocity_clipping & vehicle_imu_s::CLIPPING_Z;
		}

		imu_dt = imu.delta_angle_dt;

		if ((_device_id_accel == 0) || (_device_id_gyro == 0)) {
			_device_id_accel = imu.accel_device_id;
			_device_id_gyro = imu.gyro_device_id;
			_imu_calibration_count = imu.calibration_count;

		} else if ((imu.calibration_count > _imu_calibration_count)
			   || (imu.accel_device_id != _device_id_accel)
			   || (imu.gyro_device_id != _device_id_gyro)) {

			PX4_INFO("%d - resetting IMU bias", _instance);
			_device_id_accel = imu.accel_device_id;
			_device_id_gyro = imu.gyro_device_id;

			_ekf.resetImuBias();
			_imu_calibration_count = imu.calibration_count;
		}

	} else {
		sensor_combined_s sensor_combined;
		imu_updated = _sensor_combined_sub.update(&sensor_combined);

		imu_sample_new.time_us = sensor_combined.timestamp;
		imu_sample_new.delta_ang_dt = sensor_combined.gyro_integral_dt * 1.e-6f;
		imu_sample_new.delta_ang = Vector3f{sensor_combined.gyro_rad} * imu_sample_new.delta_ang_dt;
		imu_sample_new.delta_vel_dt = sensor_combined.accelerometer_integral_dt * 1.e-6f;
		imu_sample_new.delta_vel = Vector3f{sensor_combined.accelerometer_m_s2} * imu_sample_new.delta_vel_dt;

		if (sensor_combined.accelerometer_clipping > 0) {
			imu_sample_new.delta_vel_clipping[0] = sensor_combined.accelerometer_clipping & sensor_combined_s::CLIPPING_X;
			imu_sample_new.delta_vel_clipping[1] = sensor_combined.accelerometer_clipping & sensor_combined_s::CLIPPING_Y;
			imu_sample_new.delta_vel_clipping[2] = sensor_combined.accelerometer_clipping & sensor_combined_s::CLIPPING_Z;
		}

		imu_dt = sensor_combined.gyro_integral_dt;

		if (_sensor_selection_sub.updated() || (_device_id_accel == 0 || _device_id_gyro == 0)) {
			sensor_selection_s sensor_selection;

			if (_sensor_selection_sub.copy(&sensor_selection)) {
				if (_device_id_accel != sensor_selection.accel_device_id) {
					_ekf.resetAccelBias();
					_device_id_accel = sensor_selection.accel_device_id;
				}

				if (_device_id_gyro != sensor_selection.gyro_device_id) {
					_ekf.resetGyroBias();
					_device_id_gyro = sensor_selection.gyro_device_id;
				}
			}
		}
	}

	if (imu_updated) {
		const hrt_abstime now = imu_sample_new.time_us;

		// push imu data into estimator
		_ekf.setIMUData(imu_sample_new);
		PublishAttitude(now); // publish attitude immediately (uses quaternion from output predictor)

		// integrate time to monitor time slippage
		if (_start_time_us > 0) {
			_integrated_time_us += imu_dt;
			_last_time_slip_us = (imu_sample_new.time_us - _start_time_us) - _integrated_time_us;

		} else {
			_start_time_us = imu_sample_new.time_us;
			_last_time_slip_us = 0;
		}

		// update all other topics if they have new data
		if (_status_sub.updated()) {
			vehicle_status_s vehicle_status;

			if (_status_sub.copy(&vehicle_status)) {
				const bool is_fixed_wing = (vehicle_status.vehicle_type == vehicle_status_s::VEHICLE_TYPE_FIXED_WING);

				// only fuse synthetic sideslip measurements if conditions are met
				_ekf.set_fuse_beta_flag(is_fixed_wing && (_param_ekf2_fuse_beta.get() == 1));

				// let the EKF know if the vehicle motion is that of a fixed wing (forward flight only relative to wind)
				_ekf.set_is_fixed_wing(is_fixed_wing);

				_preflt_checker.setVehicleCanObserveHeadingInFlight(vehicle_status.vehicle_type !=
						vehicle_status_s::VEHICLE_TYPE_ROTARY_WING);

				_armed = (vehicle_status.arming_state == vehicle_status_s::ARMING_STATE_ARMED);

				// update standby (arming state) flag
				const bool standby = (vehicle_status.arming_state == vehicle_status_s::ARMING_STATE_STANDBY);

				if (_standby != standby) {
					_standby = standby;

					// reset preflight checks if transitioning in or out of standby arming state
					_preflt_checker.reset();
				}
			}
		}

		if (_vehicle_land_detected_sub.updated()) {
			vehicle_land_detected_s vehicle_land_detected;

			if (_vehicle_land_detected_sub.copy(&vehicle_land_detected)) {
				_ekf.set_in_air_status(!vehicle_land_detected.landed);

				if (_armed && (_param_ekf2_gnd_eff_dz.get() > 0.f)) {
					if (!_had_valid_terrain) {
						// update ground effect flag based on land detector state if we've never had valid terrain data
						_ekf.set_gnd_effect_flag(vehicle_land_detected.in_ground_effect);
					}

				} else {
					_ekf.set_gnd_effect_flag(false);
				}
			}
		}

		// ekf2_timestamps (using 0.1 ms relative timestamps)
		ekf2_timestamps_s ekf2_timestamps {
			.timestamp = now,
			.airspeed_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.distance_sensor_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.optical_flow_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.vehicle_air_data_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.vehicle_magnetometer_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
			.visual_odometry_timestamp_rel = ekf2_timestamps_s::RELATIVE_TIMESTAMP_INVALID,
		};

		UpdateAirspeedSample(ekf2_timestamps);
		UpdateAuxVelSample(ekf2_timestamps);
		UpdateBaroSample(ekf2_timestamps);
		UpdateGpsSample(ekf2_timestamps);
		UpdateMagSample(ekf2_timestamps);
		UpdateRangeSample(ekf2_timestamps);

		vehicle_odometry_s ev_odom;
		const bool new_ev_odom = UpdateExtVisionSample(ekf2_timestamps, ev_odom);

		optical_flow_s optical_flow;
		const bool new_optical_flow = UpdateFlowSample(ekf2_timestamps, optical_flow);


		// run the EKF update and output
		const hrt_abstime ekf_update_start = hrt_absolute_time();

		if (_ekf.update()) {
			perf_set_elapsed(_ecl_ekf_update_full_perf, hrt_elapsed_time(&ekf_update_start));

			PublishLocalPosition(now);
			PublishOdometry(now, imu_sample_new);
			PublishGlobalPosition(now);
			PublishSensorBias(now);
			PublishWindEstimate(now);

			// publish status/logging messages
			PublishEkfDriftMetrics(now);
			PublishEventFlags(now);
			PublishStates(now);
			PublishStatus(now);
			PublishStatusFlags(now);
			PublishInnovations(now, imu_sample_new);
			PublishInnovationTestRatios(now);
			PublishInnovationVariances(now);
			PublishYawEstimatorStatus(now);

			UpdateMagCalibration(now);

		} else {
			// ekf no update
			perf_set_elapsed(_ecl_ekf_update_perf, hrt_elapsed_time(&ekf_update_start));
		}

		// publish external visual odometry after fixed frame alignment if new odometry is received
		if (new_ev_odom) {
			PublishOdometryAligned(now, ev_odom);
		}

		if (new_optical_flow) {
			PublishOpticalFlowVel(now, optical_flow);
		}

		// publish ekf2_timestamps
		_ekf2_timestamps_pub.publish(ekf2_timestamps);
	}
}

void EKF2::PublishAttitude(const hrt_abstime &timestamp)
{
	if (_ekf.attitude_valid()) {
		// generate vehicle attitude quaternion data
		vehicle_attitude_s att;
		att.timestamp_sample = timestamp;
		const Quatf q{_ekf.calculate_quaternion()};
		q.copyTo(att.q);

		_ekf.get_quat_reset(&att.delta_q_reset[0], &att.quat_reset_counter);
		att.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_attitude_pub.publish(att);

	}  else if (_replay_mode) {
		// in replay mode we have to tell the replay module not to wait for an update
		// we do this by publishing an attitude with zero timestamp
		vehicle_attitude_s att{};
		_attitude_pub.publish(att);
	}
}

void EKF2::PublishEkfDriftMetrics(const hrt_abstime &timestamp)
{
	// publish GPS drift data only when updated to minimise overhead
	float gps_drift[3];
	bool blocked;

	if (_ekf.get_gps_drift_metrics(gps_drift, &blocked)) {
		ekf_gps_drift_s drift_data;
		drift_data.hpos_drift_rate = gps_drift[0];
		drift_data.vpos_drift_rate = gps_drift[1];
		drift_data.hspd = gps_drift[2];
		drift_data.blocked = blocked;
		drift_data.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

		_ekf_gps_drift_pub.publish(drift_data);
	}
}

void EKF2::PublishEventFlags(const hrt_abstime &timestamp)
{
	// information events
	uint32_t information_events = _ekf.information_event_status().value;
	bool information_event_updated = false;

	if (information_events != 0) {
		information_event_updated = true;
		_filter_information_event_changes++;
	}

	// warning events
	uint32_t warning_events = _ekf.warning_event_status().value;
	bool warning_event_updated = false;

	if (warning_events != 0) {
		warning_event_updated = true;
		_filter_warning_event_changes++;
	}

	if (information_event_updated || warning_event_updated) {
		estimator_event_flags_s event_flags{};
		event_flags.timestamp_sample = timestamp;

		event_flags.information_event_changes           = _filter_information_event_changes;
		event_flags.gps_checks_passed                   = _ekf.information_event_flags().gps_checks_passed;
		event_flags.reset_vel_to_gps                    = _ekf.information_event_flags().reset_vel_to_gps;
		event_flags.reset_vel_to_flow                   = _ekf.information_event_flags().reset_vel_to_flow;
		event_flags.reset_vel_to_vision                 = _ekf.information_event_flags().reset_vel_to_vision;
		event_flags.reset_vel_to_zero                   = _ekf.information_event_flags().reset_vel_to_zero;
		event_flags.reset_pos_to_last_known             = _ekf.information_event_flags().reset_pos_to_last_known;
		event_flags.reset_pos_to_gps                    = _ekf.information_event_flags().reset_pos_to_gps;
		event_flags.reset_pos_to_vision                 = _ekf.information_event_flags().reset_pos_to_vision;
		event_flags.starting_gps_fusion                 = _ekf.information_event_flags().starting_gps_fusion;
		event_flags.starting_vision_pos_fusion          = _ekf.information_event_flags().starting_vision_pos_fusion;
		event_flags.starting_vision_vel_fusion          = _ekf.information_event_flags().starting_vision_vel_fusion;
		event_flags.starting_vision_yaw_fusion          = _ekf.information_event_flags().starting_vision_yaw_fusion;
		event_flags.yaw_aligned_to_imu_gps              = _ekf.information_event_flags().yaw_aligned_to_imu_gps;

		event_flags.warning_event_changes               = _filter_warning_event_changes;
		event_flags.gps_quality_poor                    = _ekf.warning_event_flags().gps_quality_poor;
		event_flags.gps_fusion_timout                   = _ekf.warning_event_flags().gps_fusion_timout;
		event_flags.gps_data_stopped                    = _ekf.warning_event_flags().gps_data_stopped;
		event_flags.gps_data_stopped_using_alternate    = _ekf.warning_event_flags().gps_data_stopped_using_alternate;
		event_flags.height_sensor_timeout               = _ekf.warning_event_flags().height_sensor_timeout;
		event_flags.stopping_navigation                 = _ekf.warning_event_flags().stopping_mag_use;
		event_flags.invalid_accel_bias_cov_reset        = _ekf.warning_event_flags().invalid_accel_bias_cov_reset;
		event_flags.bad_yaw_using_gps_course            = _ekf.warning_event_flags().bad_yaw_using_gps_course;
		event_flags.stopping_mag_use                    = _ekf.warning_event_flags().stopping_mag_use;
		event_flags.vision_data_stopped                 = _ekf.warning_event_flags().vision_data_stopped;
		event_flags.emergency_yaw_reset_mag_stopped     = _ekf.warning_event_flags().emergency_yaw_reset_mag_stopped;

		event_flags.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_event_flags_pub.publish(event_flags);
	}

	_ekf.clear_information_events();
	_ekf.clear_warning_events();
}

void EKF2::PublishGlobalPosition(const hrt_abstime &timestamp)
{
	if (_ekf.global_position_is_valid() && !_preflt_checker.hasFailed()) {
		// only publish if position has changed by at least 1 mm (map_projection_reproject is relatively expensive)
		const Vector3f position{_ekf.getPosition()};

		if ((_last_local_position_for_gpos - position).longerThan(0.001f)) {
			// generate and publish global position data
			vehicle_global_position_s global_pos;
			global_pos.timestamp_sample = timestamp;

			// Position of local NED origin in GPS / WGS84 frame
			map_projection_reproject(&_ekf.global_origin(), position(0), position(1), &global_pos.lat, &global_pos.lon);

			float delta_xy[2];
			_ekf.get_posNE_reset(delta_xy, &global_pos.lat_lon_reset_counter);

			global_pos.alt = -position(2) + _ekf.getEkfGlobalOriginAltitude(); // Altitude AMSL in meters
			global_pos.alt_ellipsoid = filter_altitude_ellipsoid(global_pos.alt);

			// global altitude has opposite sign of local down position
			float delta_z;
			uint8_t z_reset_counter;
			_ekf.get_posD_reset(&delta_z, &z_reset_counter);
			global_pos.delta_alt = -delta_z;

			_ekf.get_ekf_gpos_accuracy(&global_pos.eph, &global_pos.epv);

			if (_ekf.isTerrainEstimateValid()) {
				// Terrain altitude in m, WGS84
				global_pos.terrain_alt = _ekf.getEkfGlobalOriginAltitude() - _ekf.getTerrainVertPos();
				global_pos.terrain_alt_valid = true;

			} else {
				global_pos.terrain_alt = NAN;
				global_pos.terrain_alt_valid = false;
			}

			global_pos.dead_reckoning = _ekf.inertial_dead_reckoning(); // True if this position is estimated through dead-reckoning
			global_pos.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
			_global_position_pub.publish(global_pos);

			_last_local_position_for_gpos = position;
		}
	}
}

void EKF2::PublishInnovations(const hrt_abstime &timestamp, const imuSample &imu)
{
	// publish estimator innovation data
	estimator_innovations_s innovations{};
	innovations.timestamp_sample = timestamp;
	_ekf.getGpsVelPosInnov(innovations.gps_hvel, innovations.gps_vvel, innovations.gps_hpos, innovations.gps_vpos);
	_ekf.getEvVelPosInnov(innovations.ev_hvel, innovations.ev_vvel, innovations.ev_hpos, innovations.ev_vpos);
	_ekf.getBaroHgtInnov(innovations.baro_vpos);
	_ekf.getRngHgtInnov(innovations.rng_vpos);
	_ekf.getAuxVelInnov(innovations.aux_hvel);
	_ekf.getFlowInnov(innovations.flow);
	_ekf.getHeadingInnov(innovations.heading);
	_ekf.getMagInnov(innovations.mag_field);
	_ekf.getDragInnov(innovations.drag);
	_ekf.getAirspeedInnov(innovations.airspeed);
	_ekf.getBetaInnov(innovations.beta);
	_ekf.getHaglInnov(innovations.hagl);
	// Not yet supported
	innovations.aux_vvel = NAN;

	innovations.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_innovations_pub.publish(innovations);

	// calculate noise filtered velocity innovations which are used for pre-flight checking
	if (_standby) {
		// TODO: move to run before publications
		_preflt_checker.setUsingGpsAiding(_ekf.control_status_flags().gps);
		_preflt_checker.setUsingFlowAiding(_ekf.control_status_flags().opt_flow);
		_preflt_checker.setUsingEvPosAiding(_ekf.control_status_flags().ev_pos);
		_preflt_checker.setUsingEvVelAiding(_ekf.control_status_flags().ev_vel);

		_preflt_checker.update(imu.delta_ang_dt, innovations);
	}
}

void EKF2::PublishInnovationTestRatios(const hrt_abstime &timestamp)
{
	// publish estimator innovation test ratio data
	estimator_innovations_s test_ratios{};
	test_ratios.timestamp_sample = timestamp;
	_ekf.getGpsVelPosInnovRatio(test_ratios.gps_hvel[0], test_ratios.gps_vvel, test_ratios.gps_hpos[0],
				    test_ratios.gps_vpos);
	_ekf.getEvVelPosInnovRatio(test_ratios.ev_hvel[0], test_ratios.ev_vvel, test_ratios.ev_hpos[0], test_ratios.ev_vpos);
	_ekf.getBaroHgtInnovRatio(test_ratios.baro_vpos);
	_ekf.getRngHgtInnovRatio(test_ratios.rng_vpos);
	_ekf.getAuxVelInnovRatio(test_ratios.aux_hvel[0]);
	_ekf.getFlowInnovRatio(test_ratios.flow[0]);
	_ekf.getHeadingInnovRatio(test_ratios.heading);
	_ekf.getMagInnovRatio(test_ratios.mag_field[0]);
	_ekf.getDragInnovRatio(&test_ratios.drag[0]);
	_ekf.getAirspeedInnovRatio(test_ratios.airspeed);
	_ekf.getBetaInnovRatio(test_ratios.beta);
	_ekf.getHaglInnovRatio(test_ratios.hagl);
	// Not yet supported
	test_ratios.aux_vvel = NAN;

	test_ratios.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_innovation_test_ratios_pub.publish(test_ratios);
}

void EKF2::PublishInnovationVariances(const hrt_abstime &timestamp)
{
	// publish estimator innovation variance data
	estimator_innovations_s variances{};
	variances.timestamp_sample = timestamp;
	_ekf.getGpsVelPosInnovVar(variances.gps_hvel, variances.gps_vvel, variances.gps_hpos, variances.gps_vpos);
	_ekf.getEvVelPosInnovVar(variances.ev_hvel, variances.ev_vvel, variances.ev_hpos, variances.ev_vpos);
	_ekf.getBaroHgtInnovVar(variances.baro_vpos);
	_ekf.getRngHgtInnovVar(variances.rng_vpos);
	_ekf.getAuxVelInnovVar(variances.aux_hvel);
	_ekf.getFlowInnovVar(variances.flow);
	_ekf.getHeadingInnovVar(variances.heading);
	_ekf.getMagInnovVar(variances.mag_field);
	_ekf.getDragInnovVar(variances.drag);
	_ekf.getAirspeedInnovVar(variances.airspeed);
	_ekf.getBetaInnovVar(variances.beta);
	_ekf.getHaglInnovVar(variances.hagl);
	// Not yet supported
	variances.aux_vvel = NAN;

	variances.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_innovation_variances_pub.publish(variances);
}

void EKF2::PublishLocalPosition(const hrt_abstime &timestamp)
{
	vehicle_local_position_s lpos;
	// generate vehicle local position data
	lpos.timestamp_sample = timestamp;

	// Position of body origin in local NED frame
	const Vector3f position{_ekf.getPosition()};
	lpos.x = position(0);
	lpos.y = position(1);
	lpos.z = position(2);

	// Velocity of body origin in local NED frame (m/s)
	const Vector3f velocity{_ekf.getVelocity()};
	lpos.vx = velocity(0);
	lpos.vy = velocity(1);
	lpos.vz = velocity(2);

	// vertical position time derivative (m/s)
	lpos.z_deriv = _ekf.getVerticalPositionDerivative();

	// Acceleration of body origin in local frame
	const Vector3f vel_deriv{_ekf.getVelocityDerivative()};
	lpos.ax = vel_deriv(0);
	lpos.ay = vel_deriv(1);
	lpos.az = vel_deriv(2);

	// TODO: better status reporting
	lpos.xy_valid = _ekf.local_position_is_valid() && !_preflt_checker.hasHorizFailed();
	lpos.z_valid = !_preflt_checker.hasVertFailed();
	lpos.v_xy_valid = _ekf.local_position_is_valid() && !_preflt_checker.hasHorizFailed();
	lpos.v_z_valid = !_preflt_checker.hasVertFailed();

	// Position of local NED origin in GPS / WGS84 frame
	if (_ekf.global_origin_valid()) {
		lpos.ref_timestamp = _ekf.global_origin().timestamp;
		lpos.ref_lat = math::degrees(_ekf.global_origin().lat_rad); // Reference point latitude in degrees
		lpos.ref_lon = math::degrees(_ekf.global_origin().lon_rad); // Reference point longitude in degrees
		lpos.ref_alt = _ekf.getEkfGlobalOriginAltitude();           // Reference point in MSL altitude meters
		lpos.xy_global = true;
		lpos.z_global = true;

	} else {
		lpos.ref_timestamp = 0;
		lpos.ref_lat = static_cast<double>(NAN);
		lpos.ref_lon = static_cast<double>(NAN);
		lpos.ref_alt = NAN;
		lpos.xy_global = false;
		lpos.z_global = false;
	}

	Quatf delta_q_reset;
	_ekf.get_quat_reset(&delta_q_reset(0), &lpos.heading_reset_counter);

	lpos.heading = Eulerf(_ekf.getQuaternion()).psi();
	lpos.delta_heading = Eulerf(delta_q_reset).psi();

	// Distance to bottom surface (ground) in meters
	// constrain the distance to ground to _rng_gnd_clearance
	lpos.dist_bottom = math::max(_ekf.getTerrainVertPos() - lpos.z, _param_ekf2_min_rng.get());
	lpos.dist_bottom_valid = _ekf.isTerrainEstimateValid();
	lpos.dist_bottom_sensor_bitfield = _ekf.getTerrainEstimateSensorBitfield();

	if (!_had_valid_terrain) {
		_had_valid_terrain = lpos.dist_bottom_valid;
	}

	// only consider ground effect if compensation is configured and the vehicle is armed (props spinning)
	if ((_param_ekf2_gnd_eff_dz.get() > 0.0f) && _armed && lpos.dist_bottom_valid) {
		// set ground effect flag if vehicle is closer than a specified distance to the ground
		_ekf.set_gnd_effect_flag(lpos.dist_bottom < _param_ekf2_gnd_max_hgt.get());

		// if we have no valid terrain estimate and never had one then use ground effect flag from land detector
		// _had_valid_terrain is used to make sure that we don't fall back to using this option
		// if we temporarily lose terrain data due to the distance sensor getting out of range
	}

	_ekf.get_ekf_lpos_accuracy(&lpos.eph, &lpos.epv);
	_ekf.get_ekf_vel_accuracy(&lpos.evh, &lpos.evv);

	// get state reset information of position and velocity
	_ekf.get_posD_reset(&lpos.delta_z, &lpos.z_reset_counter);
	_ekf.get_velD_reset(&lpos.delta_vz, &lpos.vz_reset_counter);
	_ekf.get_posNE_reset(&lpos.delta_xy[0], &lpos.xy_reset_counter);
	_ekf.get_velNE_reset(&lpos.delta_vxy[0], &lpos.vxy_reset_counter);

	// get control limit information
	_ekf.get_ekf_ctrl_limits(&lpos.vxy_max, &lpos.vz_max, &lpos.hagl_min, &lpos.hagl_max);

	// convert NaN to INFINITY
	if (!PX4_ISFINITE(lpos.vxy_max)) {
		lpos.vxy_max = INFINITY;
	}

	if (!PX4_ISFINITE(lpos.vz_max)) {
		lpos.vz_max = INFINITY;
	}

	if (!PX4_ISFINITE(lpos.hagl_min)) {
		lpos.hagl_min = INFINITY;
	}

	if (!PX4_ISFINITE(lpos.hagl_max)) {
		lpos.hagl_max = INFINITY;
	}

	// publish vehicle local position data
	lpos.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_local_position_pub.publish(lpos);
}

void EKF2::PublishOdometry(const hrt_abstime &timestamp, const imuSample &imu)
{
	// generate vehicle odometry data
	vehicle_odometry_s odom;
	odom.timestamp_sample = imu.time_us;

	odom.local_frame = vehicle_odometry_s::LOCAL_FRAME_NED;

	// Vehicle odometry position
	const Vector3f position{_ekf.getPosition()};
	odom.x = position(0);
	odom.y = position(1);
	odom.z = position(2);

	// Vehicle odometry linear velocity
	odom.velocity_frame = vehicle_odometry_s::LOCAL_FRAME_FRD;
	const Vector3f velocity{_ekf.getVelocity()};
	odom.vx = velocity(0);
	odom.vy = velocity(1);
	odom.vz = velocity(2);

	// Vehicle odometry quaternion
	_ekf.getQuaternion().copyTo(odom.q);

	// Vehicle odometry angular rates
	const Vector3f gyro_bias{_ekf.getGyroBias()};
	const Vector3f rates{imu.delta_ang / imu.delta_ang_dt};
	odom.rollspeed = rates(0) - gyro_bias(0);
	odom.pitchspeed = rates(1) - gyro_bias(1);
	odom.yawspeed = rates(2) - gyro_bias(2);

	// get the covariance matrix size
	static constexpr size_t POS_URT_SIZE = sizeof(odom.pose_covariance) / sizeof(odom.pose_covariance[0]);
	static constexpr size_t VEL_URT_SIZE = sizeof(odom.velocity_covariance) / sizeof(odom.velocity_covariance[0]);

	// Get covariances to vehicle odometry
	float covariances[24];
	_ekf.covariances_diagonal().copyTo(covariances);

	// initially set pose covariances to 0
	for (size_t i = 0; i < POS_URT_SIZE; i++) {
		odom.pose_covariance[i] = 0.0;
	}

	// set the position variances
	odom.pose_covariance[odom.COVARIANCE_MATRIX_X_VARIANCE] = covariances[7];
	odom.pose_covariance[odom.COVARIANCE_MATRIX_Y_VARIANCE] = covariances[8];
	odom.pose_covariance[odom.COVARIANCE_MATRIX_Z_VARIANCE] = covariances[9];

	// TODO: implement propagation from quaternion covariance to Euler angle covariance
	// by employing the covariance law

	// initially set velocity covariances to 0
	for (size_t i = 0; i < VEL_URT_SIZE; i++) {
		odom.velocity_covariance[i] = 0.0;
	}

	// set the linear velocity variances
	odom.velocity_covariance[odom.COVARIANCE_MATRIX_VX_VARIANCE] = covariances[4];
	odom.velocity_covariance[odom.COVARIANCE_MATRIX_VY_VARIANCE] = covariances[5];
	odom.velocity_covariance[odom.COVARIANCE_MATRIX_VZ_VARIANCE] = covariances[6];

	// publish vehicle odometry data
	odom.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_odometry_pub.publish(odom);
}

void EKF2::PublishOdometryAligned(const hrt_abstime &timestamp, const vehicle_odometry_s &ev_odom)
{
	const Quatf quat_ev2ekf = _ekf.getVisionAlignmentQuaternion(); // rotates from EV to EKF navigation frame
	const Dcmf ev_rot_mat(quat_ev2ekf);

	vehicle_odometry_s aligned_ev_odom{ev_odom};

	// Rotate external position and velocity into EKF navigation frame
	const Vector3f aligned_pos = ev_rot_mat * Vector3f(ev_odom.x, ev_odom.y, ev_odom.z);
	aligned_ev_odom.x = aligned_pos(0);
	aligned_ev_odom.y = aligned_pos(1);
	aligned_ev_odom.z = aligned_pos(2);

	switch (ev_odom.velocity_frame) {
	case vehicle_odometry_s::BODY_FRAME_FRD: {
			const Vector3f aligned_vel = Dcmf(_ekf.getQuaternion()) * Vector3f(ev_odom.vx, ev_odom.vy, ev_odom.vz);
			aligned_ev_odom.vx = aligned_vel(0);
			aligned_ev_odom.vy = aligned_vel(1);
			aligned_ev_odom.vz = aligned_vel(2);
			break;
		}

	case vehicle_odometry_s::LOCAL_FRAME_FRD: {
			const Vector3f aligned_vel = ev_rot_mat * Vector3f(ev_odom.vx, ev_odom.vy, ev_odom.vz);
			aligned_ev_odom.vx = aligned_vel(0);
			aligned_ev_odom.vy = aligned_vel(1);
			aligned_ev_odom.vz = aligned_vel(2);
			break;
		}
	}

	aligned_ev_odom.velocity_frame = vehicle_odometry_s::LOCAL_FRAME_NED;

	// Compute orientation in EKF navigation frame
	Quatf ev_quat_aligned = quat_ev2ekf * Quatf(ev_odom.q) ;
	ev_quat_aligned.normalize();

	ev_quat_aligned.copyTo(aligned_ev_odom.q);
	quat_ev2ekf.copyTo(aligned_ev_odom.q_offset);

	_estimator_visual_odometry_aligned_pub.publish(aligned_ev_odom);
}

void EKF2::PublishSensorBias(const hrt_abstime &timestamp)
{
	// estimator_sensor_bias
	estimator_sensor_bias_s bias{};
	bias.timestamp_sample = timestamp;

	const Vector3f gyro_bias{_ekf.getGyroBias()};
	const Vector3f accel_bias{_ekf.getAccelBias()};
	const Vector3f mag_bias{_mag_cal_last_bias};

	// only publish on change
	if ((gyro_bias - _last_gyro_bias_published).longerThan(0.001f)
	    || (accel_bias - _last_accel_bias_published).longerThan(0.001f)
	    || (mag_bias - _last_mag_bias_published).longerThan(0.001f)) {

		// take device ids from sensor_selection_s if not using specific vehicle_imu_s
		if (_device_id_gyro != 0) {
			bias.gyro_device_id = _device_id_gyro;
			gyro_bias.copyTo(bias.gyro_bias);
			bias.gyro_bias_limit = math::radians(20.f); // 20 degrees/s see Ekf::constrainStates()
			_ekf.getGyroBiasVariance().copyTo(bias.gyro_bias_variance);
			bias.gyro_bias_valid = true;

			_last_gyro_bias_published = gyro_bias;
		}

		if ((_device_id_accel != 0) && !(_param_ekf2_aid_mask.get() & MASK_INHIBIT_ACC_BIAS)) {
			bias.accel_device_id = _device_id_accel;
			accel_bias.copyTo(bias.accel_bias);
			bias.accel_bias_limit = _params->acc_bias_lim;
			_ekf.getAccelBiasVariance().copyTo(bias.accel_bias_variance);
			bias.accel_bias_valid = !_ekf.fault_status_flags().bad_acc_bias;

			_last_accel_bias_published = accel_bias;
		}

		if (_device_id_mag != 0) {
			bias.mag_device_id = _device_id_mag;
			mag_bias.copyTo(bias.mag_bias);
			bias.mag_bias_limit = 0.5f; // 0.5 Gauss see Ekf::constrainStates()
			_mag_cal_last_bias_variance.copyTo(bias.mag_bias_variance);
			bias.mag_bias_valid = _mag_cal_available;

			_last_mag_bias_published = mag_bias;
		}

		bias.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_sensor_bias_pub.publish(bias);
	}
}

void EKF2::PublishStates(const hrt_abstime &timestamp)
{
	// publish estimator states
	estimator_states_s states;
	states.timestamp_sample = timestamp;
	states.n_states = 24;
	_ekf.getStateAtFusionHorizonAsVector().copyTo(states.states);
	_ekf.covariances_diagonal().copyTo(states.covariances);
	states.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_states_pub.publish(states);
}

void EKF2::PublishStatus(const hrt_abstime &timestamp)
{
	estimator_status_s status{};
	status.timestamp_sample = timestamp;

	_ekf.getOutputTrackingError().copyTo(status.output_tracking_error);

	_ekf.get_gps_check_status(&status.gps_check_fail_flags);

	// only report enabled GPS check failures (the param indexes are shifted by 1 bit, because they don't include
	// the GPS Fix bit, which is always checked)
	status.gps_check_fail_flags &= ((uint16_t)_params->gps_check_mask << 1) | 1;

	status.control_mode_flags = _ekf.control_status().value;
	status.filter_fault_flags = _ekf.fault_status().value;

	uint16_t innov_check_flags_temp = 0;
	_ekf.get_innovation_test_status(innov_check_flags_temp, status.mag_test_ratio,
					status.vel_test_ratio, status.pos_test_ratio,
					status.hgt_test_ratio, status.tas_test_ratio,
					status.hagl_test_ratio, status.beta_test_ratio);

	// Bit mismatch between ecl and Firmware, combine the 2 first bits to preserve msg definition
	// TODO: legacy use only, those flags are also in estimator_status_flags
	status.innovation_check_flags = (innov_check_flags_temp >> 1) | (innov_check_flags_temp & 0x1);

	_ekf.get_ekf_lpos_accuracy(&status.pos_horiz_accuracy, &status.pos_vert_accuracy);
	_ekf.get_ekf_soln_status(&status.solution_status_flags);
	_ekf.getImuVibrationMetrics().copyTo(status.vibe);

	// reset counters
	status.reset_count_vel_ne = _ekf.state_reset_status().velNE_counter;
	status.reset_count_vel_d = _ekf.state_reset_status().velD_counter;
	status.reset_count_pos_ne = _ekf.state_reset_status().posNE_counter;
	status.reset_count_pod_d = _ekf.state_reset_status().posD_counter;
	status.reset_count_quat = _ekf.state_reset_status().quat_counter;

	status.time_slip = _last_time_slip_us * 1e-6f;

	status.pre_flt_fail_innov_heading = _preflt_checker.hasHeadingFailed();
	status.pre_flt_fail_innov_vel_horiz = _preflt_checker.hasHorizVelFailed();
	status.pre_flt_fail_innov_vel_vert = _preflt_checker.hasVertVelFailed();
	status.pre_flt_fail_innov_height = _preflt_checker.hasHeightFailed();
	status.pre_flt_fail_mag_field_disturbed = _ekf.control_status_flags().mag_field_disturbed;

	status.accel_device_id = _device_id_accel;
	status.baro_device_id = _device_id_baro;
	status.gyro_device_id = _device_id_gyro;
	status.mag_device_id = _device_id_mag;

	status.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
	_estimator_status_pub.publish(status);
}

void EKF2::PublishStatusFlags(const hrt_abstime &timestamp)
{
	// publish at ~ 1 Hz (or immediately if filter control status or fault status changes)
	bool update = (hrt_elapsed_time(&_last_status_flag_update) >= 1_s);

	// filter control status
	if (_ekf.control_status().value != _filter_control_status) {
		update = true;
		_filter_control_status = _ekf.control_status().value;
		_filter_control_status_changes++;
	}

	// filter fault status
	if (_ekf.fault_status().value != _filter_fault_status) {
		update = true;
		_filter_fault_status = _ekf.fault_status().value;
		_filter_fault_status_changes++;
	}

	// innovation check fail status
	if (_ekf.innov_check_fail_status().value != _innov_check_fail_status) {
		update = true;
		_innov_check_fail_status = _ekf.innov_check_fail_status().value;
		_innov_check_fail_status_changes++;
	}

	if (update) {
		estimator_status_flags_s status_flags{};
		status_flags.timestamp_sample = timestamp;

		status_flags.control_status_changes   = _filter_control_status_changes;
		status_flags.cs_tilt_align            = _ekf.control_status_flags().tilt_align;
		status_flags.cs_yaw_align             = _ekf.control_status_flags().yaw_align;
		status_flags.cs_gps                   = _ekf.control_status_flags().gps;
		status_flags.cs_opt_flow              = _ekf.control_status_flags().opt_flow;
		status_flags.cs_mag_hdg               = _ekf.control_status_flags().mag_hdg;
		status_flags.cs_mag_3d                = _ekf.control_status_flags().mag_3D;
		status_flags.cs_mag_dec               = _ekf.control_status_flags().mag_dec;
		status_flags.cs_in_air                = _ekf.control_status_flags().in_air;
		status_flags.cs_wind                  = _ekf.control_status_flags().wind;
		status_flags.cs_baro_hgt              = _ekf.control_status_flags().baro_hgt;
		status_flags.cs_rng_hgt               = _ekf.control_status_flags().rng_hgt;
		status_flags.cs_gps_hgt               = _ekf.control_status_flags().gps_hgt;
		status_flags.cs_ev_pos                = _ekf.control_status_flags().ev_pos;
		status_flags.cs_ev_yaw                = _ekf.control_status_flags().ev_yaw;
		status_flags.cs_ev_hgt                = _ekf.control_status_flags().ev_hgt;
		status_flags.cs_fuse_beta             = _ekf.control_status_flags().fuse_beta;
		status_flags.cs_mag_field_disturbed   = _ekf.control_status_flags().mag_field_disturbed;
		status_flags.cs_fixed_wing            = _ekf.control_status_flags().fixed_wing;
		status_flags.cs_mag_fault             = _ekf.control_status_flags().mag_fault;
		status_flags.cs_fuse_aspd             = _ekf.control_status_flags().fuse_aspd;
		status_flags.cs_gnd_effect            = _ekf.control_status_flags().gnd_effect;
		status_flags.cs_rng_stuck             = _ekf.control_status_flags().rng_stuck;
		status_flags.cs_gps_yaw               = _ekf.control_status_flags().gps_yaw;
		status_flags.cs_mag_aligned_in_flight = _ekf.control_status_flags().mag_aligned_in_flight;
		status_flags.cs_ev_vel                = _ekf.control_status_flags().ev_vel;
		status_flags.cs_synthetic_mag_z       = _ekf.control_status_flags().synthetic_mag_z;
		status_flags.cs_vehicle_at_rest       = _ekf.control_status_flags().vehicle_at_rest;

		status_flags.fault_status_changes     = _filter_fault_status_changes;
		status_flags.fs_bad_mag_x             = _ekf.fault_status_flags().bad_mag_x;
		status_flags.fs_bad_mag_y             = _ekf.fault_status_flags().bad_mag_y;
		status_flags.fs_bad_mag_z             = _ekf.fault_status_flags().bad_mag_z;
		status_flags.fs_bad_hdg               = _ekf.fault_status_flags().bad_hdg;
		status_flags.fs_bad_mag_decl          = _ekf.fault_status_flags().bad_mag_decl;
		status_flags.fs_bad_airspeed          = _ekf.fault_status_flags().bad_airspeed;
		status_flags.fs_bad_sideslip          = _ekf.fault_status_flags().bad_sideslip;
		status_flags.fs_bad_optflow_x         = _ekf.fault_status_flags().bad_optflow_X;
		status_flags.fs_bad_optflow_y         = _ekf.fault_status_flags().bad_optflow_Y;
		status_flags.fs_bad_vel_n             = _ekf.fault_status_flags().bad_vel_N;
		status_flags.fs_bad_vel_e             = _ekf.fault_status_flags().bad_vel_E;
		status_flags.fs_bad_vel_d             = _ekf.fault_status_flags().bad_vel_D;
		status_flags.fs_bad_pos_n             = _ekf.fault_status_flags().bad_pos_N;
		status_flags.fs_bad_pos_e             = _ekf.fault_status_flags().bad_pos_E;
		status_flags.fs_bad_pos_d             = _ekf.fault_status_flags().bad_pos_D;
		status_flags.fs_bad_acc_bias          = _ekf.fault_status_flags().bad_acc_bias;
		status_flags.fs_bad_acc_vertical      = _ekf.fault_status_flags().bad_acc_vertical;
		status_flags.fs_bad_acc_clipping      = _ekf.fault_status_flags().bad_acc_clipping;

		status_flags.innovation_fault_status_changes = _innov_check_fail_status_changes;
		status_flags.reject_hor_vel                  = _ekf.innov_check_fail_status_flags().reject_hor_vel;
		status_flags.reject_ver_vel                  = _ekf.innov_check_fail_status_flags().reject_ver_vel;
		status_flags.reject_hor_pos                  = _ekf.innov_check_fail_status_flags().reject_hor_pos;
		status_flags.reject_ver_pos                  = _ekf.innov_check_fail_status_flags().reject_ver_pos;
		status_flags.reject_mag_x                    = _ekf.innov_check_fail_status_flags().reject_mag_x;
		status_flags.reject_mag_y                    = _ekf.innov_check_fail_status_flags().reject_mag_y;
		status_flags.reject_mag_z                    = _ekf.innov_check_fail_status_flags().reject_mag_z;
		status_flags.reject_yaw                      = _ekf.innov_check_fail_status_flags().reject_yaw;
		status_flags.reject_airspeed                 = _ekf.innov_check_fail_status_flags().reject_airspeed;
		status_flags.reject_sideslip                 = _ekf.innov_check_fail_status_flags().reject_sideslip;
		status_flags.reject_hagl                     = _ekf.innov_check_fail_status_flags().reject_hagl;
		status_flags.reject_optflow_x                = _ekf.innov_check_fail_status_flags().reject_optflow_X;
		status_flags.reject_optflow_y                = _ekf.innov_check_fail_status_flags().reject_optflow_Y;

		status_flags.timestamp = _replay_mode ? timestamp : hrt_absolute_time();
		_estimator_status_flags_pub.publish(status_flags);

		_last_status_flag_update = status_flags.timestamp;
	}
}

void EKF2::PublishYawEstimatorStatus(const hrt_abstime &timestamp)
{
	static_assert(sizeof(yaw_estimator_status_s::yaw) / sizeof(float) == N_MODELS_EKFGSF,
		      "yaw_estimator_status_s::yaw wrong size");

	yaw_estimator_status_s yaw_est_test_data;

	if (_ekf.getDataEKFGSF(&yaw_est_test_data.yaw_composite, &yaw_est_test_data.yaw_variance,
			       yaw_est_test_data.yaw,
			       yaw_est_test_data.innov_vn, yaw_est_test_data.innov_ve,
			       yaw_est_test_data.weight)) {

		yaw_est_test_data.timestamp_sample = timestamp;
		yaw_est_test_data.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

		_yaw_est_pub.publish(yaw_est_test_data);
	}
}

void EKF2::PublishWindEstimate(const hrt_abstime &timestamp)
{
	if (_ekf.get_wind_status()) {
		// Publish wind estimate only if ekf declares them valid
		wind_s wind{};
		wind.timestamp_sample = timestamp;

		const Vector2f wind_vel = _ekf.getWindVelocity();
		const Vector2f wind_vel_var = _ekf.getWindVelocityVariance();
		_ekf.getAirspeedInnov(wind.tas_innov);
		_ekf.getAirspeedInnovVar(wind.tas_innov_var);
		_ekf.getBetaInnov(wind.beta_innov);
		_ekf.getBetaInnovVar(wind.beta_innov_var);

		wind.windspeed_north = wind_vel(0);
		wind.windspeed_east = wind_vel(1);
		wind.variance_north = wind_vel_var(0);
		wind.variance_east = wind_vel_var(1);
		wind.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

		_wind_pub.publish(wind);
	}
}

void EKF2::PublishOpticalFlowVel(const hrt_abstime &timestamp, const optical_flow_s &flow_sample)
{
	estimator_optical_flow_vel_s flow_vel{};
	flow_vel.timestamp_sample = flow_sample.timestamp;

	_ekf.getFlowVelBody().copyTo(flow_vel.vel_body);
	_ekf.getFlowVelNE().copyTo(flow_vel.vel_ne);
	_ekf.getFlowUncompensated().copyTo(flow_vel.flow_uncompensated_integral);
	_ekf.getFlowCompensated().copyTo(flow_vel.flow_compensated_integral);
	_ekf.getFlowGyro().copyTo(flow_vel.gyro_rate_integral);
	flow_vel.timestamp = _replay_mode ? timestamp : hrt_absolute_time();

	_estimator_optical_flow_vel_pub.publish(flow_vel);
}

float EKF2::filter_altitude_ellipsoid(float amsl_hgt)
{
	float height_diff = static_cast<float>(_gps_alttitude_ellipsoid) * 1e-3f - amsl_hgt;

	if (_gps_alttitude_ellipsoid_previous_timestamp == 0) {

		_wgs84_hgt_offset = height_diff;
		_gps_alttitude_ellipsoid_previous_timestamp = _gps_time_usec;

	} else if (_gps_time_usec != _gps_alttitude_ellipsoid_previous_timestamp) {

		// apply a 10 second first order low pass filter to baro offset
		float dt = 1e-6f * (_gps_time_usec - _gps_alttitude_ellipsoid_previous_timestamp);
		_gps_alttitude_ellipsoid_previous_timestamp = _gps_time_usec;
		float offset_rate_correction = 0.1f * (height_diff - _wgs84_hgt_offset);
		_wgs84_hgt_offset += dt * constrain(offset_rate_correction, -0.1f, 0.1f);
	}

	return amsl_hgt + _wgs84_hgt_offset;
}

void EKF2::UpdateAirspeedSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF airspeed sample
	airspeed_s airspeed;

	if (_airspeed_sub.update(&airspeed)) {
		// The airspeed measurement received via the airspeed.msg topic has not been corrected
		// for scale favtor errors and requires the ASPD_SCALE correction to be applied.
		// This could be avoided if true_airspeed_m_s from the airspeed-validated.msg topic
		// was used instead, however this would introduce a potential circular dependency
		// via the wind estimator that uses EKF velocity estimates.
		const float true_airspeed_m_s = airspeed.true_airspeed_m_s * _airspeed_scale_factor;

		// only set airspeed data if condition for airspeed fusion are met
		if ((_param_ekf2_arsp_thr.get() > FLT_EPSILON) && (true_airspeed_m_s > _param_ekf2_arsp_thr.get())) {

			airspeedSample airspeed_sample {
				.time_us = airspeed.timestamp,
				.true_airspeed = true_airspeed_m_s,
				.eas2tas = airspeed.true_airspeed_m_s / airspeed.indicated_airspeed_m_s,
			};
			_ekf.setAirspeedData(airspeed_sample);
		}

		ekf2_timestamps.airspeed_timestamp_rel = (int16_t)((int64_t)airspeed.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}
}

void EKF2::UpdateAuxVelSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF auxillary velocity sample
	//  - use the landing target pose estimate as another source of velocity data
	const unsigned last_generation = _landing_target_pose_sub.get_last_generation();
	landing_target_pose_s landing_target_pose;

	if (_landing_target_pose_sub.update(&landing_target_pose)) {

		if (_landing_target_pose_sub.get_last_generation() != last_generation + 1) {
			PX4_ERR("%d - landing_target_pose lost, generation %d -> %d", _instance, last_generation,
				_landing_target_pose_sub.get_last_generation());
		}

		// we can only use the landing target if it has a fixed position and  a valid velocity estimate
		if (landing_target_pose.is_static && landing_target_pose.rel_vel_valid) {
			// velocity of vehicle relative to target has opposite sign to target relative to vehicle
			auxVelSample auxvel_sample{
				.time_us = landing_target_pose.timestamp,
				.vel = Vector3f{-landing_target_pose.vx_rel, -landing_target_pose.vy_rel, 0.0f},
				.velVar = Vector3f{landing_target_pose.cov_vx_rel, landing_target_pose.cov_vy_rel, 0.0f},
			};
			_ekf.setAuxVelData(auxvel_sample);
		}
	}
}

void EKF2::UpdateBaroSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF baro sample
	vehicle_air_data_s airdata;

	if (_airdata_sub.update(&airdata)) {
		_ekf.set_air_density(airdata.rho);

		_ekf.setBaroData(baroSample{airdata.timestamp_sample, airdata.baro_alt_meter});

		_device_id_baro = airdata.baro_device_id;

		ekf2_timestamps.vehicle_air_data_timestamp_rel = (int16_t)((int64_t)airdata.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}
}

bool EKF2::UpdateExtVisionSample(ekf2_timestamps_s &ekf2_timestamps, vehicle_odometry_s &ev_odom)
{
	bool new_ev_odom = false;
	const unsigned last_generation = _ev_odom_sub.get_last_generation();

	// EKF external vision sample
	if (_ev_odom_sub.update(&ev_odom)) {

		if (_ev_odom_sub.get_last_generation() != last_generation + 1) {
			PX4_ERR("%d - vehicle_visual_odometry lost, generation %d -> %d", _instance, last_generation,
				_ev_odom_sub.get_last_generation());
		}

		if (_param_ekf2_aid_mask.get() & (MASK_USE_EVPOS | MASK_USE_EVYAW | MASK_USE_EVVEL)) {

			extVisionSample ev_data{};

			// if error estimates are unavailable, use parameter defined defaults

			// check for valid velocity data
			if (PX4_ISFINITE(ev_odom.vx) && PX4_ISFINITE(ev_odom.vy) && PX4_ISFINITE(ev_odom.vz)) {
				ev_data.vel(0) = ev_odom.vx;
				ev_data.vel(1) = ev_odom.vy;
				ev_data.vel(2) = ev_odom.vz;

				if (ev_odom.velocity_frame == vehicle_odometry_s::BODY_FRAME_FRD) {
					ev_data.vel_frame = velocity_frame_t::BODY_FRAME_FRD;

				} else {
					ev_data.vel_frame = velocity_frame_t::LOCAL_FRAME_FRD;
				}

				// velocity measurement error from ev_data or parameters
				float param_evv_noise_var = sq(_param_ekf2_evv_noise.get());

				if (!_param_ekf2_ev_noise_md.get() && PX4_ISFINITE(ev_odom.velocity_covariance[ev_odom.COVARIANCE_MATRIX_VX_VARIANCE])
				    && PX4_ISFINITE(ev_odom.velocity_covariance[ev_odom.COVARIANCE_MATRIX_VY_VARIANCE])
				    && PX4_ISFINITE(ev_odom.velocity_covariance[ev_odom.COVARIANCE_MATRIX_VZ_VARIANCE])) {
					ev_data.velCov(0, 0) = ev_odom.velocity_covariance[ev_odom.COVARIANCE_MATRIX_VX_VARIANCE];
					ev_data.velCov(0, 1) = ev_data.velCov(1, 0) = ev_odom.velocity_covariance[1];
					ev_data.velCov(0, 2) = ev_data.velCov(2, 0) = ev_odom.velocity_covariance[2];
					ev_data.velCov(1, 1) = ev_odom.velocity_covariance[ev_odom.COVARIANCE_MATRIX_VY_VARIANCE];
					ev_data.velCov(1, 2) = ev_data.velCov(2, 1) = ev_odom.velocity_covariance[7];
					ev_data.velCov(2, 2) = ev_odom.velocity_covariance[ev_odom.COVARIANCE_MATRIX_VZ_VARIANCE];

				} else {
					ev_data.velCov = matrix::eye<float, 3>() * param_evv_noise_var;
				}
			}

			// check for valid position data
			if (PX4_ISFINITE(ev_odom.x) && PX4_ISFINITE(ev_odom.y) && PX4_ISFINITE(ev_odom.z)) {
				ev_data.pos(0) = ev_odom.x;
				ev_data.pos(1) = ev_odom.y;
				ev_data.pos(2) = ev_odom.z;

				float param_evp_noise_var = sq(_param_ekf2_evp_noise.get());

				// position measurement error from ev_data or parameters
				if (!_param_ekf2_ev_noise_md.get() && PX4_ISFINITE(ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_X_VARIANCE])
				    && PX4_ISFINITE(ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_Y_VARIANCE])
				    && PX4_ISFINITE(ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_Z_VARIANCE])) {
					ev_data.posVar(0) = fmaxf(param_evp_noise_var, ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_X_VARIANCE]);
					ev_data.posVar(1) = fmaxf(param_evp_noise_var, ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_Y_VARIANCE]);
					ev_data.posVar(2) = fmaxf(param_evp_noise_var, ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_Z_VARIANCE]);

				} else {
					ev_data.posVar.setAll(param_evp_noise_var);
				}
			}

			// check for valid orientation data
			if (PX4_ISFINITE(ev_odom.q[0])) {
				ev_data.quat = Quatf(ev_odom.q);

				// orientation measurement error from ev_data or parameters
				float param_eva_noise_var = sq(_param_ekf2_eva_noise.get());

				if (!_param_ekf2_ev_noise_md.get() && PX4_ISFINITE(ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_YAW_VARIANCE])) {
					ev_data.angVar = fmaxf(param_eva_noise_var, ev_odom.pose_covariance[ev_odom.COVARIANCE_MATRIX_YAW_VARIANCE]);

				} else {
					ev_data.angVar = param_eva_noise_var;
				}
			}

			// use timestamp from external computer, clocks are synchronized when using MAVROS
			ev_data.time_us = ev_odom.timestamp_sample;
			_ekf.setExtVisionData(ev_data);

			new_ev_odom = true;
		}

		ekf2_timestamps.visual_odometry_timestamp_rel = (int16_t)((int64_t)ev_odom.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}

	return new_ev_odom;
}

bool EKF2::UpdateFlowSample(ekf2_timestamps_s &ekf2_timestamps, optical_flow_s &optical_flow)
{
	bool new_optical_flow = false;
	const unsigned last_generation = _optical_flow_sub.get_last_generation();

	if (_optical_flow_sub.update(&optical_flow)) {

		if (_optical_flow_sub.get_last_generation() != last_generation + 1) {
			PX4_ERR("%d - optical_flow lost, generation %d -> %d", _instance, last_generation,
				_optical_flow_sub.get_last_generation());
		}

		if (_param_ekf2_aid_mask.get() & MASK_USE_OF) {

			flowSample flow {
				.time_us = optical_flow.timestamp,
				// NOTE: the EKF uses the reverse sign convention to the flow sensor. EKF assumes positive LOS rate
				// is produced by a RH rotation of the image about the sensor axis.
				.flow_xy_rad = Vector2f{-optical_flow.pixel_flow_x_integral, -optical_flow.pixel_flow_y_integral},
				.gyro_xyz = Vector3f{-optical_flow.gyro_x_rate_integral, -optical_flow.gyro_y_rate_integral, -optical_flow.gyro_z_rate_integral},
				.dt = 1e-6f * (float)optical_flow.integration_timespan,
				.quality = optical_flow.quality,
			};

			if (PX4_ISFINITE(optical_flow.pixel_flow_y_integral) &&
			    PX4_ISFINITE(optical_flow.pixel_flow_x_integral) &&
			    flow.dt < 1) {

				// Save sensor limits reported by the optical flow sensor
				_ekf.set_optical_flow_limits(optical_flow.max_flow_rate, optical_flow.min_ground_distance,
							     optical_flow.max_ground_distance);

				_ekf.setOpticalFlowData(flow);

				new_optical_flow = true;
			}
		}

		ekf2_timestamps.optical_flow_timestamp_rel = (int16_t)((int64_t)optical_flow.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}

	return new_optical_flow;
}

void EKF2::UpdateGpsSample(ekf2_timestamps_s &ekf2_timestamps)
{
	// EKF GPS message
	if (_param_ekf2_aid_mask.get() & MASK_USE_GPS) {
		vehicle_gps_position_s vehicle_gps_position;

		if (_vehicle_gps_position_sub.update(&vehicle_gps_position)) {
			gps_message gps_msg{
				.time_usec = vehicle_gps_position.timestamp,
				.lat = vehicle_gps_position.lat,
				.lon = vehicle_gps_position.lon,
				.alt = vehicle_gps_position.alt,
				.yaw = vehicle_gps_position.heading,
				.yaw_offset = vehicle_gps_position.heading_offset,
				.fix_type = vehicle_gps_position.fix_type,
				.eph = vehicle_gps_position.eph,
				.epv = vehicle_gps_position.epv,
				.sacc = vehicle_gps_position.s_variance_m_s,
				.vel_m_s = vehicle_gps_position.vel_m_s,
				.vel_ned = Vector3f{
					vehicle_gps_position.vel_n_m_s,
					vehicle_gps_position.vel_e_m_s,
					vehicle_gps_position.vel_d_m_s
				},
				.vel_ned_valid = vehicle_gps_position.vel_ned_valid,
				.nsats = vehicle_gps_position.satellites_used,
				.pdop = sqrtf(vehicle_gps_position.hdop *vehicle_gps_position.hdop
					      + vehicle_gps_position.vdop * vehicle_gps_position.vdop),
			};
			_ekf.setGpsData(gps_msg);

			_gps_time_usec = gps_msg.time_usec;
			_gps_alttitude_ellipsoid = vehicle_gps_position.alt_ellipsoid;
		}
	}
}

void EKF2::UpdateMagSample(ekf2_timestamps_s &ekf2_timestamps)
{
	const unsigned last_generation = _magnetometer_sub.get_last_generation();
	vehicle_magnetometer_s magnetometer;

	if (_magnetometer_sub.update(&magnetometer)) {

		if (_magnetometer_sub.get_last_generation() != last_generation + 1) {
			PX4_ERR("%d - vehicle_magnetometer lost, generation %d -> %d", _instance, last_generation,
				_magnetometer_sub.get_last_generation());
		}

		bool reset = false;

		// check if magnetometer has changed
		if (magnetometer.device_id != _device_id_mag) {
			if (_device_id_mag != 0) {
				PX4_WARN("%d - mag sensor ID changed %d -> %d", _instance, _device_id_mag, magnetometer.device_id);
			}

			reset = true;

		} else if (magnetometer.calibration_count > _mag_calibration_count) {
			// existing calibration has changed, reset saved mag bias
			PX4_DEBUG("%d - mag %d calibration updated, resetting bias", _instance, _device_id_mag);
			reset = true;
		}

		if (reset) {
			_ekf.resetMagBias();
			_device_id_mag = magnetometer.device_id;
			_mag_calibration_count = magnetometer.calibration_count;

			// reset magnetometer bias learning
			_mag_cal_total_time_us = 0;
			_mag_cal_last_us = 0;
			_mag_cal_available = false;
		}

		_ekf.setMagData(magSample{magnetometer.timestamp_sample, Vector3f{magnetometer.magnetometer_ga}});

		ekf2_timestamps.vehicle_magnetometer_timestamp_rel = (int16_t)((int64_t)magnetometer.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);
	}
}

void EKF2::UpdateRangeSample(ekf2_timestamps_s &ekf2_timestamps)
{
	if (!_distance_sensor_selected) {
		// get subscription index of first downward-facing range sensor
		uORB::SubscriptionMultiArray<distance_sensor_s> distance_sensor_subs{ORB_ID::distance_sensor};

		for (unsigned i = 0; i < distance_sensor_subs.size(); i++) {
			distance_sensor_s distance_sensor;

			if (distance_sensor_subs[i].copy(&distance_sensor)) {
				// only use the first instace which has the correct orientation
				if ((hrt_elapsed_time(&distance_sensor.timestamp) < 100_ms)
				    && (distance_sensor.orientation == distance_sensor_s::ROTATION_DOWNWARD_FACING)) {

					if (_distance_sensor_sub.ChangeInstance(i)) {
						PX4_INFO("%d - selected distance_sensor:%d", _instance, i);
						_distance_sensor_selected = true;
					}
				}
			}
		}
	}

	// EKF range sample
	const unsigned last_generation = _distance_sensor_sub.get_last_generation();
	distance_sensor_s distance_sensor;

	if (_distance_sensor_sub.update(&distance_sensor)) {

		if (_distance_sensor_sub.get_last_generation() != last_generation + 1) {
			PX4_ERR("%d - distance_sensor lost, generation %d -> %d", _instance, last_generation,
				_distance_sensor_sub.get_last_generation());
		}

		ekf2_timestamps.distance_sensor_timestamp_rel = (int16_t)((int64_t)distance_sensor.timestamp / 100 -
				(int64_t)ekf2_timestamps.timestamp / 100);

		if (distance_sensor.orientation == distance_sensor_s::ROTATION_DOWNWARD_FACING) {
			rangeSample range_sample {
				.time_us = distance_sensor.timestamp,
				.rng = distance_sensor.current_distance,
				.quality = distance_sensor.signal_quality,
			};
			_ekf.setRangeData(range_sample);

			// Save sensor limits reported by the rangefinder
			_ekf.set_rangefinder_limits(distance_sensor.min_distance, distance_sensor.max_distance);

			_last_range_sensor_update = distance_sensor.timestamp;
			return;
		}
	}

	if (hrt_elapsed_time(&_last_range_sensor_update) > 1_s) {
		_distance_sensor_selected = false;
	}
}

void EKF2::UpdateMagCalibration(const hrt_abstime &timestamp)
{
	// Check if conditions are OK for learning of magnetometer bias values
	// the EKF is operating in the correct mode and there are no filter faults
	if (_ekf.control_status_flags().in_air && _ekf.control_status_flags().mag_3D && (_ekf.fault_status().value == 0)) {

		if (_mag_cal_last_us != 0) {
			_mag_cal_total_time_us += timestamp - _mag_cal_last_us;

			// Start checking mag bias estimates when we have accumulated sufficient calibration time
			if (_mag_cal_total_time_us > 30_s) {
				_mag_cal_last_bias = _ekf.getMagBias();
				_mag_cal_last_bias_variance = _ekf.getMagBiasVariance();
				_mag_cal_available = true;
			}
		}

		_mag_cal_last_us = timestamp;

	} else {
		// conditions are NOT OK for learning magnetometer bias, reset timestamp
		// but keep the accumulated calibration time
		_mag_cal_last_us = 0;

		if (_ekf.fault_status().value != 0) {
			// if a filter fault has occurred, assume previous learning was invalid and do not
			// count it towards total learning time.
			_mag_cal_total_time_us = 0;
		}
	}

	if (!_armed) {
		// update stored declination value
		if (!_mag_decl_saved) {
			float declination_deg;

			if (_ekf.get_mag_decl_deg(&declination_deg)) {
				_param_ekf2_mag_decl.set(declination_deg);
				_mag_decl_saved = true;

				if (!_multi_mode) {
					_param_ekf2_mag_decl.commit_no_notification();
				}
			}
		}
	}
}

int EKF2::custom_command(int argc, char *argv[])
{
	return print_usage("unknown command");
}

int EKF2::task_spawn(int argc, char *argv[])
{
	bool success = false;
	bool replay_mode = false;

	if (argc > 1 && !strcmp(argv[1], "-r")) {
		PX4_INFO("replay mode enabled");
		replay_mode = true;
	}

#if !defined(CONSTRAINED_FLASH)
	bool multi_mode = false;
	int32_t imu_instances = 0;
	int32_t mag_instances = 0;

	int32_t sens_imu_mode = 1;
	param_get(param_find("SENS_IMU_MODE"), &sens_imu_mode);

	if (sens_imu_mode == 0) {
		// ekf selector requires SENS_IMU_MODE = 0
		multi_mode = true;

		// IMUs (1 - 4 supported)
		param_get(param_find("EKF2_MULTI_IMU"), &imu_instances);

		if (imu_instances < 1 || imu_instances > 4) {
			const int32_t imu_instances_limited = math::constrain(imu_instances, 1, 4);
			PX4_WARN("EKF2_MULTI_IMU limited %d -> %d", imu_instances, imu_instances_limited);
			param_set_no_notification(param_find("EKF2_MULTI_IMU"), &imu_instances_limited);
			imu_instances = imu_instances_limited;
		}

		int32_t sens_mag_mode = 1;
		param_get(param_find("SENS_MAG_MODE"), &sens_mag_mode);

		if (sens_mag_mode == 0) {
			param_get(param_find("EKF2_MULTI_MAG"), &mag_instances);

			// Mags (1 - 4 supported)
			if (mag_instances < 1 || mag_instances > 4) {
				const int32_t mag_instances_limited = math::constrain(mag_instances, 1, 4);
				PX4_WARN("EKF2_MULTI_MAG limited %d -> %d", mag_instances, mag_instances_limited);
				param_set_no_notification(param_find("EKF2_MULTI_MAG"), &mag_instances_limited);
				mag_instances = mag_instances_limited;
			}

		} else {
			mag_instances = 1;
		}
	}

	if (multi_mode) {
		// Start EKF2Selector if it's not already running
		if (_ekf2_selector.load() == nullptr) {
			EKF2Selector *inst = new EKF2Selector();

			if (inst) {
				_ekf2_selector.store(inst);

			} else {
				PX4_ERR("Failed to create EKF2 selector");
				return PX4_ERROR;
			}
		}

		const hrt_abstime time_started = hrt_absolute_time();
		const int multi_instances = math::min(imu_instances * mag_instances, (int)EKF2_MAX_INSTANCES);
		int multi_instances_allocated = 0;

		// allocate EKF2 instances until all found or arming
		uORB::SubscriptionData<vehicle_status_s> vehicle_status_sub{ORB_ID(vehicle_status)};

		bool ekf2_instance_created[4][4] {}; // IMUs * mags

		while ((multi_instances_allocated < multi_instances)
		       && (vehicle_status_sub.get().arming_state != vehicle_status_s::ARMING_STATE_ARMED)
		       && (hrt_elapsed_time(&time_started) < 30_s)) {

			vehicle_status_sub.update();

			for (uint8_t mag = 0; mag < mag_instances; mag++) {
				uORB::SubscriptionData<vehicle_magnetometer_s> vehicle_mag_sub{ORB_ID(vehicle_magnetometer), mag};

				for (uint8_t imu = 0; imu < imu_instances; imu++) {

					uORB::SubscriptionData<vehicle_imu_s> vehicle_imu_sub{ORB_ID(vehicle_imu), imu};
					vehicle_mag_sub.update();

					// Mag & IMU data must be valid, first mag can be ignored initially
					if ((vehicle_mag_sub.get().device_id != 0 || mag == 0)
					    && (vehicle_imu_sub.get().accel_device_id != 0)
					    && (vehicle_imu_sub.get().gyro_device_id != 0)) {

						if (!ekf2_instance_created[imu][mag]) {
							EKF2 *ekf2_inst = new EKF2(true, px4::ins_instance_to_wq(imu), false);

							if (ekf2_inst && ekf2_inst->multi_init(imu, mag)) {
								int actual_instance = ekf2_inst->instance(); // match uORB instance numbering

								if ((actual_instance >= 0) && (_objects[actual_instance].load() == nullptr)) {
									_objects[actual_instance].store(ekf2_inst);
									ekf2_inst->ScheduleNow();
									success = true;
									multi_instances_allocated++;
									ekf2_instance_created[imu][mag] = true;

									PX4_INFO("starting instance %d, IMU:%d (%d), MAG:%d (%d)", actual_instance,
										 imu, vehicle_imu_sub.get().accel_device_id,
										 mag, vehicle_mag_sub.get().device_id);

									_ekf2_selector.load()->ScheduleNow();

								} else {
									PX4_ERR("instance numbering problem instance: %d", actual_instance);
									delete ekf2_inst;
									break;
								}

							} else {
								PX4_ERR("alloc and init failed imu: %d mag:%d", imu, mag);
								px4_usleep(1000000);
								break;
							}
						}

					} else {
						px4_usleep(50000); // give the sensors extra time to start
						continue;
					}
				}
			}

			if (multi_instances_allocated < multi_instances) {
				px4_usleep(100000);
			}
		}

	}

#endif // !CONSTRAINED_FLASH

	else {
		// otherwise launch regular
		EKF2 *ekf2_inst = new EKF2(false, px4::wq_configurations::INS0, replay_mode);

		if (ekf2_inst) {
			_objects[0].store(ekf2_inst);
			ekf2_inst->ScheduleNow();
			success = true;
		}
	}

	return success ? PX4_OK : PX4_ERROR;
}

int EKF2::print_usage(const char *reason)
{
	if (reason) {
		PX4_WARN("%s\n", reason);
	}

	PRINT_MODULE_DESCRIPTION(
		R"DESCR_STR(
### Description
Attitude and position estimator using an Extended Kalman Filter. It is used for Multirotors and Fixed-Wing.

The documentation can be found on the [ECL/EKF Overview & Tuning](https://docs.px4.io/master/en/advanced_config/tuning_the_ecl_ekf.html) page.

ekf2 can be started in replay mode (`-r`): in this mode it does not access the system time, but only uses the
timestamps from the sensor topics.

)DESCR_STR");

	PRINT_MODULE_USAGE_NAME("ekf2", "estimator");
	PRINT_MODULE_USAGE_COMMAND("start");
	PRINT_MODULE_USAGE_PARAM_FLAG('r', "Enable replay mode", true);
	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();

	return 0;
}

extern "C" __EXPORT int ekf2_main(int argc, char *argv[])
{
	if (argc <= 1 || strcmp(argv[1], "-h") == 0) {
		return EKF2::print_usage();
	}

	if (strcmp(argv[1], "start") == 0) {
		int ret = 0;
		EKF2::lock_module();

		ret = EKF2::task_spawn(argc - 1, argv + 1);

		if (ret < 0) {
			PX4_ERR("start failed (%i)", ret);
		}

		EKF2::unlock_module();
		return ret;

	} else if (strcmp(argv[1], "status") == 0) {
		if (EKF2::trylock_module()) {
#if !defined(CONSTRAINED_FLASH)
			if (_ekf2_selector.load()) {
				_ekf2_selector.load()->PrintStatus();
			}
#endif // !CONSTRAINED_FLASH

			for (int i = 0; i < EKF2_MAX_INSTANCES; i++) {
				if (_objects[i].load()) {
					PX4_INFO_RAW("\n");
					_objects[i].load()->print_status();
				}
			}

			EKF2::unlock_module();

		} else {
			PX4_WARN("module locked, try again later");
		}

		return 0;

	} else if (strcmp(argv[1], "stop") == 0) {
		EKF2::lock_module();

		if (argc > 2) {
			int instance = atoi(argv[2]);

			if (instance >= 0 && instance < EKF2_MAX_INSTANCES) {
				PX4_INFO("stopping instance %d", instance);
				EKF2 *inst = _objects[instance].load();

				if (inst) {
					inst->request_stop();
					px4_usleep(20000); // 20 ms
					delete inst;
					_objects[instance].store(nullptr);
				}
			} else {
				PX4_ERR("invalid instance %d", instance);
			}

		} else {
			// otherwise stop everything
			bool was_running = false;

#if !defined(CONSTRAINED_FLASH)
			if (_ekf2_selector.load()) {
				PX4_INFO("stopping ekf2 selector");
				_ekf2_selector.load()->Stop();
				delete _ekf2_selector.load();
				_ekf2_selector.store(nullptr);
				was_running = true;
			}
#endif // !CONSTRAINED_FLASH

			for (int i = 0; i < EKF2_MAX_INSTANCES; i++) {
				EKF2 *inst = _objects[i].load();

				if (inst) {
					PX4_INFO("stopping ekf2 instance %d", i);
					was_running = true;
					inst->request_stop();
					px4_usleep(20000); // 20 ms
					delete inst;
					_objects[i].store(nullptr);
				}
			}

			if (!was_running) {
				PX4_WARN("not running");
			}
		}

		EKF2::unlock_module();
		return PX4_OK;
	}

	EKF2::lock_module(); // Lock here, as the method could access _object.
	int ret = EKF2::custom_command(argc - 1, argv + 1);
	EKF2::unlock_module();

	return ret;
}