attitude_estimator_ekf: acc compensation and magnetic declination fixes

1 files changed, 27 insertions, 15 deletions

diff --git a/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp b/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp
index efa6d97fd..36e82db43 100755
--- a/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp
+++ b/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp
@@ -62,6 +62,8 @@
 #include <uORB/topics/parameter_update.h>
 #include <drivers/drv_hrt.h>
 
+#include <lib/mathlib/mathlib.h>
+
 #include <systemlib/systemlib.h>
 #include <systemlib/perf_counter.h>
 #include <systemlib/err.h>
@@ -274,6 +276,13 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 	float gyro_offsets[3] = { 0.0f, 0.0f, 0.0f };
 	unsigned offset_count = 0;
 
+	/* actual acceleration (by GPS velocity) in body frame */
+	float acc[3] = { 0.0f, 0.0f, 0.0f };
+
+	/* rotation matrix for magnetic declination */
+	math::Matrix<3, 3> R_decl;
+	R_decl.identity();
+
 	/* register the perf counter */
 	perf_counter_t ekf_loop_perf = perf_alloc(PC_ELAPSED, "attitude_estimator_ekf");
 
@@ -308,6 +317,9 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 
 				/* update parameters */
 				parameters_update(&ekf_param_handles, &ekf_params);
+
+				/* update mag declination rotation matrix */
+				R_decl.from_euler(0.0f, 0.0f, ekf_params.mag_decl);
 			}
 
 			/* only run filter if sensor values changed */
@@ -362,7 +374,6 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 						sensor_last_timestamp[1] = raw.timestamp;
 					}
 
-					float acc[3];
 					if (gps.fix_type >= 3 && gps.eph_m < 10.0f && gps.vel_ned_valid && hrt_absolute_time() < gps.timestamp_velocity + 500000) {
 						if (last_gps != 0 && gps.timestamp_velocity != last_gps) {
 							float gps_dt = (gps.timestamp_velocity - last_gps) / 1000000.0f;
@@ -379,20 +390,18 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 									acc[i] += att.R[j][i] * acc_NED[j];
 								}
 							}
+
+							vel_prev[0] = gps.vel_n_m_s;
+							vel_prev[1] = gps.vel_e_m_s;
+							vel_prev[2] = gps.vel_d_m_s;
 						}
+						last_gps = gps.timestamp_velocity;
 
 					} else {
 						acc[0] = 0.0f;
 						acc[1] = 0.0f;
 						acc[2] = 0.0f;
-					}
 
-					if (gps.vel_ned_valid) {
-						vel_prev[0] = gps.vel_n_m_s;
-						vel_prev[1] = gps.vel_e_m_s;
-						vel_prev[2] = gps.vel_d_m_s;
-						last_gps = gps.timestamp_velocity;
-					} else {
 						vel_prev[0] = 0.0f;
 						vel_prev[1] = 0.0f;
 						vel_prev[2] = 0.0f;
@@ -472,7 +481,7 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 						continue;
 					}
 
-					if (last_data > 0 && raw.timestamp - last_data > 12000)
+					if (last_data > 0 && raw.timestamp - last_data > 30000)
 						printf("[attitude estimator ekf] sensor data missed! (%llu)\n", raw.timestamp - last_data);
 
 					last_data = raw.timestamp;
@@ -480,10 +489,9 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 					/* send out */
 					att.timestamp = raw.timestamp;
 
-					// XXX Apply the same transformation to the rotation matrix
-					att.roll = euler[0] - ekf_params.roll_off;
-					att.pitch = euler[1] - ekf_params.pitch_off;
-					att.yaw = euler[2] - ekf_params.yaw_off;
+					att.roll = euler[0];
+					att.pitch = euler[1];
+					att.yaw = euler[2] + ekf_params.mag_decl;
 
 					att.rollspeed = x_aposteriori[0];
 					att.pitchspeed = x_aposteriori[1];
@@ -492,12 +500,16 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 					att.pitchacc = x_aposteriori[4];
 					att.yawacc = x_aposteriori[5];
 
-					//att.yawspeed =z_k[2] ;
 					/* copy offsets */
 					memcpy(&att.rate_offsets, &(x_aposteriori[3]), sizeof(att.rate_offsets));
 
+					/* magnetic declination */
+
+					math::Matrix<3, 3> R_body = (&Rot_matrix[0]);
+					math::Matrix<3, 3> R = R_decl * R_body;
+
 					/* copy rotation matrix */
-					memcpy(&att.R, Rot_matrix, sizeof(Rot_matrix));
+					memcpy(&att.R[0][0], &R.data[0][0], sizeof(att.R));
 					att.R_valid = true;
 
 					if (isfinite(att.roll) && isfinite(att.pitch) && isfinite(att.yaw)) {