ekf2: expand accel bias stability criteria

src/modules/ekf2/EKF/common.h

@@ -548,7 +548,7 @@ union warning_event_status_u {
 		bool gps_data_stopped_using_alternate	: 1; ///< 3 - true when the gps data has stopped for a significant time period but the filter is able to use other sources of data to maintain navigation
 		bool height_sensor_timeout		: 1; ///< 4 - true when the height sensor has not been used to correct the state estimates for a significant time period
 		bool stopping_navigation		: 1; ///< 5 - true when the filter has insufficient data to estimate velocity and position and is falling back to an attitude, height and height rate mode of operation
-		bool invalid_accel_bias_cov_reset	: 1; ///< 6 - true when the filter has detected bad acceerometer bias state esitmstes and has reset the corresponding covariance matrix elements
+		bool invalid_accel_bias_cov_reset	: 1; ///< 6 - true when the filter has detected bad acceerometer bias state estimates and has reset the corresponding covariance matrix elements
 		bool bad_yaw_using_gps_course		: 1; ///< 7 - true when the fiter has detected an invalid yaw esitmate and has reset the yaw angle to the GPS ground course
 		bool stopping_mag_use			: 1; ///< 8 - true when the filter has detected bad magnetometer data and is stopping further use of the magnetomer data
 		bool vision_data_stopped		: 1; ///< 9 - true when the vision system data has stopped for a significant time period

src/modules/ekf2/EKF/ekf.h

@@ -244,6 +244,8 @@ public:
 	Vector3f getAccelBiasVariance() const { return Vector3f{P(13, 13), P(14, 14), P(15, 15)} / sq(_dt_ekf_avg); } // get the accelerometer bias variance in m/s**2
 	Vector3f getMagBiasVariance() const { return Vector3f{P(19, 19), P(20, 20), P(21, 21)}; }
 
+	bool accel_bias_inhibited() const { return _accel_bias_inhibit[0] || _accel_bias_inhibit[1] || _accel_bias_inhibit[2]; }
+
 	// get GPS check status
 	void get_gps_check_status(uint16_t *val) const { *val = _gps_check_fail_status.value; }