ekf2: add param to set rng check hysteresis

src/modules/ekf2/EKF2.cpp

@@ -117,6 +117,7 @@ EKF2::EKF2(bool multi_mode, const px4::wq_config_t &config, bool replay_mode):
 	_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),

src/modules/ekf2/EKF2.hpp

@@ -389,6 +389,8 @@ private:
 		_param_ekf2_rng_a_hmax,	///< maximum allowed absolute altitude (AGL) for range aid (m)
 		(ParamExtFloat<px4::params::EKF2_RNG_A_IGATE>)
 		_param_ekf2_rng_a_igate,	///< gate size used for innovation consistency checks for range aid fusion (STD)
+		(ParamExtFloat<px4::params::EKF2_RNG_QLTY_T>)
+		_param_ekf2_rng_qlty_t, ///< Minimum duration during which the reported range finder signal quality needs to be non-zero in order to be declared valid (s)
 
 		// vision estimate fusion
 		(ParamInt<px4::params::EKF2_EV_NOISE_MD>)

src/modules/ekf2/ekf2_params.c

@@ -1097,6 +1097,17 @@ PARAM_DEFINE_FLOAT(EKF2_RNG_A_HMAX, 5.0f);
  */
 PARAM_DEFINE_FLOAT(EKF2_RNG_A_IGATE, 1.0f);
 
+/**
+ * Minimum duration during which the reported range finder signal quality needs to be non-zero in order to be declared valid (s)
+ *
+ *
+ * @group EKF2
+ * @unit s
+ * @min 0.1
+ * @max 5
+*/
+PARAM_DEFINE_FLOAT(EKF2_RNG_QLTY_T, 1.0f);
+
 /**
  * Gate size for vision velocity estimate fusion
  *