ekf2: Enable tuning of initial tilt alignment uncertainty

src/modules/ekf2/ekf2_main.cpp

@@ -251,6 +251,7 @@ private:
 	// IMU switch on bias paameters
 	control::BlockParamFloat _gyr_bias_init;	// 1-sigma gyro bias uncertainty at switch-on (rad/sec)
 	control::BlockParamFloat _acc_bias_init;	// 1-sigma accelerometer bias uncertainty at switch-on (m/s**2)
+	control::BlockParamFloat _ang_err_init;		// 1-sigma uncertainty in tilt angle after gravity vector alignment (rad)
 
 	int update_subscriptions();
 
@@ -338,7 +339,8 @@ Ekf2::Ekf2():
 	_tau_vel(this, "EKF2_TAU_VEL", false, &_params->vel_Tau),
 	_tau_pos(this, "EKF2_TAU_POS", false, &_params->pos_Tau),
 	_gyr_bias_init(this, "EKF2_GBIAS_INIT", false, &_params->switch_on_gyro_bias),
-	_acc_bias_init(this, "EKF2_ABIAS_INIT", false, &_params->switch_on_accel_bias)
+	_acc_bias_init(this, "EKF2_ABIAS_INIT", false, &_params->switch_on_accel_bias),
+	_ang_err_init(this, "EKF2_ANGERR_INIT", false, &_params->initial_tilt_err)
 {
 
 }

src/modules/ekf2/ekf2_params.c

@@ -743,3 +743,14 @@ PARAM_DEFINE_FLOAT(EKF2_GBIAS_INIT, 0.1f);
  * @decimal 2
  */
 PARAM_DEFINE_FLOAT(EKF2_ABIAS_INIT, 0.2f);
+
+/**
+ * 1-sigma tilt angle uncertainty after gravity vector alignment
+ *
+ * @group EKF2
+ * @min 0.0
+ * @max 0.5
+ * @unit rad
+ * @decimal 3
+ */
+PARAM_DEFINE_FLOAT(EKF2_ANGERR_INIT, 0.1f);