EKF: Add interfaces and variables to use ext vision data

EKF/common.h

@@ -71,6 +71,13 @@ struct flow_message {
 	uint32_t dt;				// integration time of flow samples
 };
 
+struct ext_vision_message {
+	Vector3f posNED;  // measured NED position relative to the local origin (m)
+	Quaternion quat;  // measured quaternion orientation defining rotation from NED to body frame
+	float posErr;     // 1-Sigma spherical position accuracy (m)
+	float angErr;     // 1-Sigma angular error (rad)
+};
+
 struct outputSample {
 	Quaternion  quat_nominal;	// nominal quaternion describing vehicle attitude
 	Vector3f    vel;	// NED velocity estimate in earth frame in m/s
@@ -126,6 +133,14 @@ struct flowSample {
 	uint64_t time_us; // timestamp in microseconds of the integration period mid-point
 };
 
+struct extVisionSample {
+	Vector3f posNED;  // measured NED position relative to the local origin (m)
+	Quaternion quat;  // measured quaternion orientation defining rotation from NED to body frame
+	float posErr;     // 1-Sigma spherical position accuracy (m)
+	float angErr;     // 1-Sigma angular error (rad)
+	uint64_t time_us; // timestamp of the measurement in microseconds
+};
+
 // Integer definitions for vdist_sensor_type
 #define VDIST_SENSOR_BARO  0	// Use baro height
 #define VDIST_SENSOR_GPS   1	// Use GPS height
@@ -140,6 +155,8 @@ struct flowSample {
 #define MASK_USE_GPS    (1<<0)  // set to true to use GPS data
 #define MASK_USE_OF     (1<<1)  // set to true to use optical flow data
 #define MASK_INHIBIT_ACC_BIAS (1<<2)  // set to true to inhibit estimation of accelerometer delta velocity bias
+#define MASK_USE_EVPOS	(1<<3)  // set to true to use external vision NED position data
+#define MASK_USE_EVYAW  (1<<4)	// set to true to use exernal vision quaternion data for yaw
 
 // Integer definitions for mag_fusion_type
 #define MAG_FUSE_TYPE_AUTO      0   // The selection of either heading or 3D magnetometer fusion will be automatic
@@ -163,6 +180,7 @@ struct parameters {
 	float airspeed_delay_ms;	// airspeed measurement delay relative to the IMU (msec)
 	float flow_delay_ms;		// optical flow measurement delay relative to the IMU (msec) - this is to the middle of the optical flow integration interval
 	float range_delay_ms;		// range finder measurement delay relative to the IMU (msec)
+	float ev_delay_ms;		// off-board vision measurement delay relative to the IMU (msec)
 
 	// input noise
 	float gyro_noise;		// IMU angular rate noise used for covariance prediction (rad/sec)
@@ -247,6 +265,7 @@ struct parameters {
 		airspeed_delay_ms = 200.0f;
 		flow_delay_ms = 5.0f;
 		range_delay_ms = 5.0f;
+		ev_delay_ms = 100.0f;
 
 		// input noise
 		gyro_noise = 1.5e-2f;
@@ -383,6 +402,8 @@ union filter_control_status_u {
 		uint16_t baro_hgt    : 1; // 9 - true when baro height is being fused as a primary height reference
 		uint16_t rng_hgt     : 1; // 10 - true when range finder height is being fused as a primary height reference
 		uint16_t gps_hgt     : 1; // 11 - true when range finder height is being fused as a primary height reference
+		uint16_t ev_pos      : 1; // 12 - true when local position data from external vision is being fused
+		uint16_t ev_yaw      : 1; // 13 - true when yaw data from external vision measurements is being fused
 	} flags;
 	uint16_t value;
 };