Class containting the methods and attributes for a Fossen robot-like hydrodynamic model. The restoring forces are applied by the BuoyantObject class methods. Using the plugin for UUV models will use both this and the buoyant object class definitions, therefore the restoring forces were not inherited here. References: More...

#include <HydrodynamicModel.hh>

Inheritance diagram for gazebo::HMFossen:

[legend]

Public Member Functions
virtual void	ApplyHydrodynamicForces (double time, const ignition::math::Vector3d &_flowVelWorld)
	Computation of the hydrodynamic forces. More...

virtual bool	GetParam (std::string _tag, std::vector< double > &_output)
	Return paramater in vector form for the given tag. More...

virtual bool	GetParam (std::string _tag, double &_output)
	Return paramater in scalar form for the given tag. More...

virtual std::string	GetType ()
	Return (derived) type of hydrodynamic model. More...

virtual void	Print (std::string _paramName, std::string _message=std::string())
	Prints parameters. More...

virtual bool	SetParam (std::string _tag, double _input)
	Set scalar parameter. More...

Public Member Functions inherited from gazebo::BuoyantObject
void	ApplyBuoyancyForce ()
	Applies buoyancy force on link. More...

	BuoyantObject (physics::LinkPtr _link)
	Constructor. More...

void	GetBuoyancyForce (const ignition::math::Pose3d &_pose, ignition::math::Vector3d &buoyancyForce, ignition::math::Vector3d &buoyancyTorque)
	Returns the buoyancy force vector in the world frame. More...

ignition::math::Vector3d	GetCoB ()
	Returns the stored center of buoyancy. More...

bool	GetDebugFlag ()
	Returns the debug flag. More...

double	GetFluidDensity ()
	Returns the stored fluid density. More...

double	GetGravity ()
	Get stored acceleration of gravity. More...

ignition::math::Vector3d	GetStoredVector (std::string _tag)
	Get vector from the hydroWrench map. More...

double	GetVolume ()
	Returns the stored link submerged volume. More...

bool	IsNeutrallyBuoyant ()
	Returns true if the link was set to be neutrally buoyant. More...

bool	IsSubmerged ()
	Returns true if the robot is completely submerged. More...

void	SetBoundingBox (const ignition::math::Box &_bBox)
	Sets bounding box. More...

void	SetCoB (const ignition::math::Vector3d &_centerOfBuoyancy)
	Sets the position of the center of buoyancy on the body frame. More...

void	SetDebugFlag (bool _debugOn=true)
	Set debug flag to store intermediate forces and torques. More...

void	SetFluidDensity (double _fluidDensity)
	Sets the fluid density in kg/m^3. More...

void	SetGravity (double _g)
	Set acceleration of gravity. More...

void	SetNeutrallyBuoyant ()
	Sets this link as neutrally buoyant. More...

void	SetStoreVector (std::string _tag)
	Adds a field in the hydroWrench map. More...

void	SetVolume (double _volume=-1)
	Sets the link's submerged volume. More...

	~BuoyantObject ()
	Destructor. More...

Static Public Member Functions
static HydrodynamicModel *	create (sdf::ElementPtr _sdf, physics::LinkPtr _link)
	Create model of this type with parameter values from sdf. More...

Protected Member Functions
void	ComputeAddedCoriolisMatrix (const Eigen::Vector6d &_vel, const Eigen::Matrix6d &_Ma, Eigen::Matrix6d &_Ca) const
	Computes the added-mass Coriolis matrix Ca. More...

void	ComputeDampingMatrix (const Eigen::Vector6d &_vel, Eigen::Matrix6d &_D) const
	Updates the damping matrix for the current velocity. More...

Eigen::Matrix6d	GetAddedMass () const
	Returns the added-mass matrix with the scaling and offset. More...

	HMFossen (sdf::ElementPtr _sdf, physics::LinkPtr _link)

	REGISTER_HYDRODYNAMICMODEL (HMFossen)
	Register this model with the factory. More...

Protected Member Functions inherited from gazebo::HydrodynamicModel
bool	CheckParams (sdf::ElementPtr _sdf)
	Returns true if all parameters are available from the SDF element. More...

void	ComputeAcc (Eigen::Vector6d _velRel, double _time, double _alpha=0.3)
	Filter acceleration (fix due to the update structure of Gazebo) More...

ignition::math::Vector3d	FromNED (ignition::math::Vector3d _vec)
	Convert vector to comply with the NED reference frame. More...

	HydrodynamicModel (sdf::ElementPtr _sdf, physics::LinkPtr _link)
	Protected constructor: Use the factory for object creation. More...

ignition::math::Vector3d	ToNED (ignition::math::Vector3d _vec)
	Convert vector to comply with the NED reference frame. More...

Protected Member Functions inherited from gazebo::BuoyantObject
void	StoreVector (std::string _tag, ignition::math::Vector3d _vec)
	Store vector in the hydroWrench map if the field has been created. More...

Protected Attributes
Eigen::Matrix6d	Ca
	Added-mass associated Coriolis matrix. More...

Eigen::Matrix6d	D
	Damping matrix. More...

Eigen::Matrix6d	DLin
	Linear damping matrix. More...

Eigen::Matrix6d	DLinForwardSpeed
	Linear damping matrix proportional only to the forward speed (useful for modeling AUVs). From [1], according to Newman (1977), there is a damping force component that linearly increases with the presence of forward speed, particularly so for slender bodies. More...

Eigen::Matrix6d	DNonLin
	Nonlinear damping coefficients. More...

std::vector< double >	linearDampCoef
	Linear damping coefficients. More...

Eigen::Matrix6d	Ma
	Added-mass matrix. More...

double	offsetAddedMass
	Offset for the added-mass matrix. More...

double	offsetLinearDamping
	Offset for the linear damping matrix. More...

double	offsetLinForwardSpeedDamping
	Offset for the linear damping matrix. More...

double	offsetNonLinDamping
	Offset for the linear damping matrix. More...

std::vector< double >	quadDampCoef
	Quadratic damping coefficients. More...

double	scalingAddedMass
	Scaling of the added-mass matrix. More...

double	scalingDamping
	Scaling of the damping matrix. More...

Protected Attributes inherited from gazebo::HydrodynamicModel
Eigen::Vector6d	filteredAcc
	Filtered linear & angular acceleration vector in link frame. This is used to prevent the model to become unstable given that Gazebo only calls the update function at the beginning or at the end of a iteration of the physics engine. More...

double	lastTime
	Last timestamp (in seconds) at which ApplyHydrodynamicForces was called. More...

Eigen::Vector6d	lastVelRel
	Last body-fixed relative velocity (nu_R in Fossen's equations) More...

std::vector< std::string >	params
	List of parameters needed from the SDF element. More...

double	Re
	Reynolds number (not used by all models) More...

double	temperature
	Temperature (not used by all models) More...

Protected Attributes inherited from gazebo::BuoyantObject
ignition::math::Box	boundingBox
	TEMP for calculation of the buoyancy force close to the surface. More...

ignition::math::Vector3d	centerOfBuoyancy
	Center of buoyancy in the body frame. More...

bool	debugFlag
	Debug flag, storing all intermediate forces and torques. More...

double	fluidDensity
	Fluid density. More...

double	g
	Acceleration of gravity. More...

std::map< std::string, ignition::math::Vector3d >	hydroWrench
	Storage for hydrodynamic and hydrostatic forces and torques for debugging purposes. More...

bool	isSubmerged
	Is submerged flag. More...

bool	isSurfaceVessel
	Flag set to true if the information about the metacentric width and height is available. More...

bool	isSurfaceVesselFloating
	Flag set to true if the vessel has reached its submerged height. More...

physics::LinkPtr	link
	Pointer to the correspondent robot link. More...

double	metacentricLength
	Metacentric length of the robot, used only for surface vessels and floating objects. More...

double	metacentricWidth

bool	neutrallyBuoyant
	If true, the restoring force will be equal to the gravitational. More...

double	offsetVolume
	Offset for the volume. More...

double	scalingVolume
	Scaling factor for the volume. More...

double	submergedHeight
	Height of the robot that is submerged (only for surface vessels) More...

double	volume
	Volume of fluid displaced by the submerged object. More...

double	waterLevelPlaneArea
	If the cross section area around water level of the surface vessel is not given, it will be computed from the object's bounding box. More...

Static Protected Attributes
static const std::string	IDENTIFIER = "fossen"
	Unique identifier for this geometry. More...

Detailed Description

Class containting the methods and attributes for a Fossen robot-like hydrodynamic model. The restoring forces are applied by the BuoyantObject class methods. Using the plugin for UUV models will use both this and the buoyant object class definitions, therefore the restoring forces were not inherited here. References:

Fossen, Thor, "Handbook of Marine Craft and Hydrodynamics and Motion Control", 2011

Definition at line 153 of file HydrodynamicModel.hh.

Constructor & Destructor Documentation

gazebo::HMFossen::HMFossen	(	sdf::ElementPtr	_sdf,
		physics::LinkPtr	_link
	)

protected

Definition at line 223 of file HydrodynamicModel.cc.

Member Function Documentation

void gazebo::HMFossen::ApplyHydrodynamicForces	(	double	time,
		const ignition::math::Vector3d &	_flowVelWorld
	)

virtual

Computation of the hydrodynamic forces.

Implements gazebo::HydrodynamicModel.

Definition at line 360 of file HydrodynamicModel.cc.

void gazebo::HMFossen::ComputeAddedCoriolisMatrix	(	const Eigen::Vector6d &	_vel,
		const Eigen::Matrix6d &	_Ma,
		Eigen::Matrix6d &	_Ca
	)		const

protected

Computes the added-mass Coriolis matrix Ca.

Definition at line 449 of file HydrodynamicModel.cc.

void gazebo::HMFossen::ComputeDampingMatrix	(	const Eigen::Vector6d &	_vel,
		Eigen::Matrix6d &	_D
	)		const

protected

Updates the damping matrix for the current velocity.

Definition at line 463 of file HydrodynamicModel.cc.

HydrodynamicModel * gazebo::HMFossen::create	(	sdf::ElementPtr	_sdf,
		physics::LinkPtr	_link
	)

static

Create model of this type with parameter values from sdf.

Definition at line 216 of file HydrodynamicModel.cc.

Eigen::Matrix6d gazebo::HMFossen::GetAddedMass ( ) const

protected

Returns the added-mass matrix with the scaling and offset.

Definition at line 490 of file HydrodynamicModel.cc.

bool gazebo::HMFossen::GetParam	(	std::string	_tag,
		std::vector< double > &	_output
	)

virtual

Return paramater in vector form for the given tag.

Implements gazebo::HydrodynamicModel.

Definition at line 497 of file HydrodynamicModel.cc.

bool gazebo::HMFossen::GetParam	(	std::string	_tag,
		double &	_output
	)

virtual

Return paramater in scalar form for the given tag.

Implements gazebo::HydrodynamicModel.

Definition at line 540 of file HydrodynamicModel.cc.

virtual std::string gazebo::HMFossen::GetType ( )

inlinevirtual

Return (derived) type of hydrodynamic model.

Implements gazebo::HydrodynamicModel.

Reimplemented in gazebo::HMBox, gazebo::HMSpheroid, gazebo::HMCylinder, and gazebo::HMSphere.

Definition at line 160 of file HydrodynamicModel.hh.

void gazebo::HMFossen::Print	(	std::string	_paramName,
		std::string	_message = `std::string()`
	)

virtual

Prints parameters.

Implements gazebo::HydrodynamicModel.

Reimplemented in gazebo::HMBox, gazebo::HMSpheroid, gazebo::HMCylinder, and gazebo::HMSphere.

Definition at line 625 of file HydrodynamicModel.cc.

gazebo::HMFossen::REGISTER_HYDRODYNAMICMODEL ( HMFossen )

protected

Register this model with the factory.

bool gazebo::HMFossen::SetParam	(	std::string	_tag,
		double	_input
	)

virtual

Set scalar parameter.

Implements gazebo::HydrodynamicModel.

Definition at line 581 of file HydrodynamicModel.cc.

Member Data Documentation

Eigen::Matrix6d gazebo::HMFossen::Ca

protected

Added-mass associated Coriolis matrix.

Definition at line 210 of file HydrodynamicModel.hh.

Eigen::Matrix6d gazebo::HMFossen::D

protected

Damping matrix.

Definition at line 213 of file HydrodynamicModel.hh.

Eigen::Matrix6d gazebo::HMFossen::DLin

protected

Linear damping matrix.

Definition at line 228 of file HydrodynamicModel.hh.

Eigen::Matrix6d gazebo::HMFossen::DLinForwardSpeed

protected

Linear damping matrix proportional only to the forward speed (useful for modeling AUVs). From [1], according to Newman (1977), there is a damping force component that linearly increases with the presence of forward speed, particularly so for slender bodies.

References: [1] Refsnes - 2007 - Nonlinear model-based control of slender body AUVs

Definition at line 237 of file HydrodynamicModel.hh.

Eigen::Matrix6d gazebo::HMFossen::DNonLin

protected

Nonlinear damping coefficients.

Definition at line 240 of file HydrodynamicModel.hh.

const std::string gazebo::HMFossen::IDENTIFIER = "fossen"

staticprotected

Unique identifier for this geometry.

Definition at line 180 of file HydrodynamicModel.hh.

std::vector<double> gazebo::HMFossen::linearDampCoef

protected

Linear damping coefficients.

Definition at line 243 of file HydrodynamicModel.hh.

Eigen::Matrix6d gazebo::HMFossen::Ma

protected

Added-mass matrix.

Definition at line 201 of file HydrodynamicModel.hh.

double gazebo::HMFossen::offsetAddedMass

protected

Offset for the added-mass matrix.

Definition at line 207 of file HydrodynamicModel.hh.

double gazebo::HMFossen::offsetLinearDamping

protected

Offset for the linear damping matrix.

Definition at line 219 of file HydrodynamicModel.hh.

double gazebo::HMFossen::offsetLinForwardSpeedDamping

protected

Offset for the linear damping matrix.

Definition at line 222 of file HydrodynamicModel.hh.

double gazebo::HMFossen::offsetNonLinDamping

protected

Offset for the linear damping matrix.

Definition at line 225 of file HydrodynamicModel.hh.

std::vector<double> gazebo::HMFossen::quadDampCoef

protected

Quadratic damping coefficients.

Definition at line 246 of file HydrodynamicModel.hh.

double gazebo::HMFossen::scalingAddedMass

protected

Scaling of the added-mass matrix.

Definition at line 204 of file HydrodynamicModel.hh.

double gazebo::HMFossen::scalingDamping

protected

Scaling of the damping matrix.

Definition at line 216 of file HydrodynamicModel.hh.

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation