From bd50092dd29a83dd5044fc3027e20be91b3275e5 Mon Sep 17 00:00:00 2001 From: Anton Babushkin Date: Sun, 21 Jul 2013 22:44:46 +0400 Subject: position_estimator_inav: accelerometer bias estimation for Z, default weights for GPS updated --- .../position_estimator_inav_main.c | 20 ++++++++++++++------ .../position_estimator_inav_params.c | 9 ++++++--- .../position_estimator_inav_params.h | 2 ++ 3 files changed, 22 insertions(+), 9 deletions(-) (limited to 'src/modules') diff --git a/src/modules/position_estimator_inav/position_estimator_inav_main.c b/src/modules/position_estimator_inav/position_estimator_inav_main.c index a9bc09e0d..42b5fcb61 100644 --- a/src/modules/position_estimator_inav/position_estimator_inav_main.c +++ b/src/modules/position_estimator_inav/position_estimator_inav_main.c @@ -167,9 +167,9 @@ int position_estimator_inav_thread_main(int argc, char *argv[]) int baro_init_num = 200; float baro_alt0 = 0.0f; /* to determine while start up */ - double lat_current = 0.0; //[°]] --> 47.0 - double lon_current = 0.0; //[°]] -->8.5 - double alt_current = 0.0; //[m] above MSL + double lat_current = 0.0f; //[°] --> 47.0 + double lon_current = 0.0f; //[°] --> 8.5 + double alt_current = 0.0f; //[m] above MSL uint32_t accel_counter = 0; uint32_t baro_counter = 0; @@ -302,8 +302,12 @@ int position_estimator_inav_thread_main(int argc, char *argv[]) hrt_abstime pub_last = hrt_absolute_time(); uint32_t pub_interval = 4000; // limit publish rate to 250 Hz + /* acceleration in NED frame */ + float accel_NED[3] = { 0.0f, 0.0f, -CONSTANTS_ONE_G }; + /* store error when sensor updates, but correct on each time step to avoid jumps in estimated value */ float accel_corr[] = { 0.0f, 0.0f, 0.0f }; // N E D + float accel_bias[] = { 0.0f, 0.0f, 0.0f }; // body frame float baro_corr = 0.0f; // D float gps_corr[2][2] = { { 0.0f, 0.0f }, // N (pos, vel) @@ -369,9 +373,9 @@ int position_estimator_inav_thread_main(int argc, char *argv[]) if (sensor.accelerometer_counter > accel_counter) { if (att.R_valid) { + /* correct accel bias, now only for Z */ + sensor.accelerometer_m_s2[2] -= accel_bias[2]; /* transform acceleration vector from body frame to NED frame */ - float accel_NED[3]; - for (int i = 0; i < 3; i++) { accel_NED[i] = 0.0f; @@ -425,7 +429,7 @@ int position_estimator_inav_thread_main(int argc, char *argv[]) local_pos.home_timestamp = hrt_absolute_time(); z_est[0] += sonar_corr; sonar_corr = 0.0f; - sonar_corr_filtered = 0.0; + sonar_corr_filtered = 0.0f; } } } @@ -470,6 +474,10 @@ int position_estimator_inav_thread_main(int argc, char *argv[]) float dt = t_prev > 0 ? (t - t_prev) / 1000000.0f : 0.0f; t_prev = t; + /* accel bias correction, now only for Z + * not strictly correct, but stable and works */ + accel_bias[2] += (accel_NED[2] + CONSTANTS_ONE_G) * params.w_acc_bias * dt; + /* inertial filter prediction for altitude */ inertial_filter_predict(dt, z_est); diff --git a/src/modules/position_estimator_inav/position_estimator_inav_params.c b/src/modules/position_estimator_inav/position_estimator_inav_params.c index c90c611a7..70248b3b7 100644 --- a/src/modules/position_estimator_inav/position_estimator_inav_params.c +++ b/src/modules/position_estimator_inav/position_estimator_inav_params.c @@ -44,10 +44,11 @@ PARAM_DEFINE_INT32(INAV_USE_GPS, 1); PARAM_DEFINE_FLOAT(INAV_W_ALT_BARO, 1.0f); PARAM_DEFINE_FLOAT(INAV_W_ALT_ACC, 50.0f); PARAM_DEFINE_FLOAT(INAV_W_ALT_SONAR, 3.0f); -PARAM_DEFINE_FLOAT(INAV_W_POS_GPS_P, 4.0f); -PARAM_DEFINE_FLOAT(INAV_W_POS_GPS_V, 0.0f); +PARAM_DEFINE_FLOAT(INAV_W_POS_GPS_P, 1.0f); +PARAM_DEFINE_FLOAT(INAV_W_POS_GPS_V, 2.0f); PARAM_DEFINE_FLOAT(INAV_W_POS_ACC, 10.0f); -PARAM_DEFINE_FLOAT(INAV_W_POS_FLOW, 10.0f); +PARAM_DEFINE_FLOAT(INAV_W_POS_FLOW, 0.0f); +PARAM_DEFINE_FLOAT(INAV_W_ACC_BIAS, 0.0f); PARAM_DEFINE_FLOAT(INAV_FLOW_K, 1.0f); PARAM_DEFINE_FLOAT(INAV_SONAR_FILT, 0.02f); PARAM_DEFINE_FLOAT(INAV_SONAR_ERR, 0.5f); @@ -62,6 +63,7 @@ int parameters_init(struct position_estimator_inav_param_handles *h) h->w_pos_gps_v = param_find("INAV_W_POS_GPS_V"); h->w_pos_acc = param_find("INAV_W_POS_ACC"); h->w_pos_flow = param_find("INAV_W_POS_FLOW"); + h->w_acc_bias = param_find("INAV_W_ACC_BIAS"); h->flow_k = param_find("INAV_FLOW_K"); h->sonar_filt = param_find("INAV_SONAR_FILT"); h->sonar_err = param_find("INAV_SONAR_ERR"); @@ -79,6 +81,7 @@ int parameters_update(const struct position_estimator_inav_param_handles *h, str param_get(h->w_pos_gps_v, &(p->w_pos_gps_v)); param_get(h->w_pos_acc, &(p->w_pos_acc)); param_get(h->w_pos_flow, &(p->w_pos_flow)); + param_get(h->w_acc_bias, &(p->w_acc_bias)); param_get(h->flow_k, &(p->flow_k)); param_get(h->sonar_filt, &(p->sonar_filt)); param_get(h->sonar_err, &(p->sonar_err)); diff --git a/src/modules/position_estimator_inav/position_estimator_inav_params.h b/src/modules/position_estimator_inav/position_estimator_inav_params.h index cca172b5d..1e70a3c48 100644 --- a/src/modules/position_estimator_inav/position_estimator_inav_params.h +++ b/src/modules/position_estimator_inav/position_estimator_inav_params.h @@ -49,6 +49,7 @@ struct position_estimator_inav_params { float w_pos_gps_v; float w_pos_acc; float w_pos_flow; + float w_acc_bias; float flow_k; float sonar_filt; float sonar_err; @@ -63,6 +64,7 @@ struct position_estimator_inav_param_handles { param_t w_pos_gps_v; param_t w_pos_acc; param_t w_pos_flow; + param_t w_acc_bias; param_t flow_k; param_t sonar_filt; param_t sonar_err; -- cgit v1.2.3