Message definitions

These are the definitions of the messages used for the communication with the LRAUV through topics or services, please have a look at the API for more details on that. It uses the Gazebo Messages library, so please refer to the documentation for more details on the message passing system.

lrauv_gazebo_plugins.msgs

DVLBeamState

Name	Type	Default	Notes
id	int32		Beam ID
velocity	DVLKinematicEstimate		Beam velocity estimate.
range	DVLRangeEstimate		Beam range estimate.
rssi	double		Beam signal strength indicator.
nsd	double		Measured background noise spectral density.
locked	bool		Whether beam is locked or not.

DVLKinematicEstimate

Name	Type	Default	Notes
reference	ReferenceType		Estimate frame of reference (incl. conventions). ReferenceType is an enum with the values: DVL_REFERENCE_UNSPECIFIED, DVL_REFERENCE_EARTH, DVL_REFERENCE_SHIP and DVL_REFERENCE_BEAM.
mean	gz.msgs.Vector3d		Estimate mean.
covariance	repeated double		Estimate covariance matrix. A 3 x 3 row-major matrix using a flat contiguous layout.

DVLRangeEstimate

Name	Type	Default	Notes
mean	double		Estimate mean.
variance	double		Estimate variance.

DVLTrackingTarget

Name	Type	Default	Notes
type	TargetType		Type of target used for tracking, can any value from: DVL_TARGET_UNSPECIFIED, DVL_TARGET_BOTTOM or DVL_TARGET_WATER_MASS
range	DVLRangeEstimate		Target range (or distance).
position	DVLKinematicEstimate		Target position estimate.

DVLVelocityTracking

Name	Type	Default	Notes
header	gz.msgs.Header		Message header.
type	DVLType		Type of DVL. Possible values: DVL_TYPE_UNSPECIFIED, DVL_TYPE_PISTON or DVL_TYPE_PHASED_ARRAY.
target	DVLTrackingTarget		Locked on target.
velocity	DVLKinematicEstimate		Estimated velocity.
beams	repeated DVLBeamState		Tracking beams' state.
status	int32		Vendor-specific status (e.g. bitmask, error code)

LRAUVAcousticMessage

Name	Type	Default	Notes
to	uint32
from	uint32
type	MessageType		MessageType is an enum. It can be of a value RangeRequest RangeResponse or Other.
data	bytes

LRAUVCommand

Name	Type	Default	Notes
header	gz.msgs.Header		Optional header data.
propOmega_	float		Angular velocity in rad/s that the controller believes the propeller is currently at. Positive values rotate the propeller clockwise when looking from the back, and propel the vehicle forward.
rudderAngle_	float		Angle in radians that the controller believes the rudder is currently at. Higher values have the vertical fins rotated more clockwise when looking from the top (i.e. to starboard).
elevatorAngle_	float		Angle in radians that the controller believes the elevator is currently at. Higher values have the horizontal fins rotated more counter-clockwise when looking from starboard, which tilts the nose downward when moving forward.
massPosition_	float		Position in meters where the controller believes the mass shifter's joint is in. Positive values have the battery forward, tilting the nose downward.
buoyancyPosition_	float		Volume in cubic meters that the controller believes the VBS currently has. Volumes higher than the neutral volume push the vehicle upward.
dropWeightState_	bool		Indicator "dropweight OK". 1 = in place, 0 = dropped
propOmegaAction_	float		Target angular velocity in rad/s for the propeller. Positive values rotate the propeller clockwise when looking from the back, and propel the vehicle forward.
rudderAngleAction_	float		Target angle in radians for rudder joint. Higher values rotate the vertical fins clockwise when looking from the top (i.e. to starboard).
elevatorAngleAction_	float		Target angle in radians for the elevator joint. Higher values rotate vertical fins more counter-clockwise when looking from starboard, which tilts the nose downward when moving forward.
massPositionAction_	float		Target in meters position for the battery's joint. Positive values move the battery forward, tilting the nose downward.
buoyancyAction_	float		Target volume in cubic meters for the VBS (Variable Buoyancy System). Volumes higher than the neutral volume make the vehicle float.
density_	float		Not used
dt_	float		Not used
time_	float		Not used

LRAUVInit

Name	Type	Default	Notes
header	gz.msgs.Header		Optional header data.
id_	gz.msgs.StringMsg		Unique ID identifying vehicle.
initLat_	double		Initial latitude in degrees.
initLon_	double		Initial longitude in degrees.
initZ_	double		Initial depth in meters.
initPitch_	float		Initial pitch in radians with respect to the NED world frame (i.e. rotation about the East vector).
initRoll_	float		Initial roll in radians with respect to the NED world frame (i.e. rotation about the North vector).
initHeading_	float		Initial heading in radians with respect to the NED world frame i.e. rotation about the Down vector).
acommsAddress_	uint32		Unique acoustic comms modem ID

LRAUVInternalComms

Name	Type	Default	Notes
header	gz.msgs.Header		Optional header data.
position	gz.msgs.Vector3d
to	uint32
from	uint32
type	MessageType		MessageType is an enum. It can be of a value RangeRequest RangeResponse or Other
data	bytes

LRAUVRangeBearingRequest

Name	Type	Default	Notes
to	uint32
from	uint32

lrauv_range_bearing_response

LRAUVRangeBearingResponse

Name	Type	Default	Notes
req_id	uint32		Request ID. Each request ID must be unique.
bearing	gz.msgs.Vector3d		Bearing in terms of (r, elevation, azimuth). This is based on ground truth and not calculated using time-of-flight
range	double		Time-Of-Flight reading. This is good for studying errors arising due to movement. But at high dt this may be prone to error.

LRAUVState

Name	Type	Default	Notes
header	gz.msgs.Header		Optional header data. Stamped with simulation time.
errorPad_	int32		Not populated.
utmZone_	int32		Not populated.
northernHemi_	int32		Not populated.
propOmega_	float		Current angular velocity in rad/s of the propeller. Positive values rotate the propeller clockwise when looking from the back, and propel the vehicle forward.
propThrust_	float		Not populated.
propTorque_	float		Not populated.
rudderAngle_	float		Angle in radians that the rudder joint is currently at. Higher values have the vertical fins rotated more clockwise when looking from the top (i.e. to starboard).
elevatorAngle_	float		Angle in radians that the elevator joint is currently at. Higher values have the horizontal fins rotated more counter-clockwise when looking from starboard, which tilts the nose downward when moving forward.
massPosition_	float		Position in meters of the battery's joint. Positive values have the battery forward, tilting the nose downward.
buoyancyPosition_	float		Volume in cubic meters of the VBS. Volumes higher than the neutral volume push the vehicle upwards.
depth_	float		Vertical position of the vehicle with respect to sea level. Higher values are deeper, negative values are above water. Unit: meters.
rph_	gz.msgs.Vector3d		Duplicate of posRPH_
speed_	float		Magnitude of vehicle's linear velocity in the world frame in m/s. It's always positive.
latitudeDeg_	double		Latitude in degrees.
longitudeDeg_	double		Longitude in degrees.
netBuoy_	float		Net buoyancy forces in newtons applied to the vehicle. Currently not populated.
force_	gz.msgs.Vector3d		Not populated
pos_	gz.msgs.Vector3d		Vehicle's position in meters in "world frame" (see above).
posRPH_	gz.msgs.Vector3d		Vehicle's orientation in radians in "world frame" (see above).
posDot_	gz.msgs.Vector3d		Vehicle's instantaneous linear velocity in m/s in "world frame"
rateUVW_	gz.msgs.Vector3d		Vehicle's instantaneous linear velocity in m/s in "vehicle frame" (see above).
ratePQR_	gz.msgs.Vector3d		Vehicle's instantaneous angular velocity in rad/s in "vehicle frame" (see above).
northCurrent_	float		Northward sea water velocity collected from current sensor in m/s.
eastCurrent_	float		Eastward sea water velocity collected from current sensor in m/s.
vertCurrent_	float		Not populated.
magneticVariation_	float		Not populated.
soundSpeed_	float		Not populated.
temperature_	float		Data collected from temperature sensor in celsius.
salinity_	float		Data collected from salinity sensor in PSU.
density_	float		Density of the surrounding water in kg / m ^ 3
values_	repeated float		Size 4. 0: Data collected from Chlorophyll sensor in ug / L. 1: Pressure calculated from current depth and latitude in Pa.
batteryVoltage_	double		Voltage of the battery.
batteryCurrent_	double		Current supplied by the battery in A.
batteryCharge_	double		Current charge in the battery in Ah.
batteryPercentage_	double		Percentage of battery remaining.