Inheritance diagram for CCable:

Collaboration diagram for CCable:

Public Member Functions
	CCable (const std::string &simObjectName, ISimObjectCreator *const creator)
	Reads parameters, registers states, input/output ports and shared resources.

void	OdeFcn (const double T, const double const X, double const XDot) const
	free allocated memory

void	InitialConditionSetup (const double T, const double const currentIC, double const updatedIC, ISimObjectCreator *const creator)
	Sets initial conditions based on the value of input ports.

void	FinalSetup (const double T, const double const X, ISimObjectCreator const creator)

const double *	ForceA (const double T, const double *const X)
	retrieves pointer to environment object

const double *	ForceB (const double T, const double *const X)
	output port. See PortDefs.h. Returns force at point A

void	computeEndForces (const double T, const double *const X) const
	output port. See PortDefs.h. Returns force at point B

bool	HasJacobians () const override
	pointer to environment object

void	OdeJacobian (double T, const double X, double J, int nStates) override

int	GetJacobianSparsity (int nStates, int rowPtr, int colIdx) override

Protected Member Functions
void	computeSegmentForces (const double T, const double X, const double pA, const double pB, const double vA, const double vB, double FA, double *FB) const
	computes free nodes and both end forces

void	computeVirtualPoint (const double const target, const double const point, const double const targetVel, const double const pointVel, double virtualPoint, double virtualPointVel, double residual, double dResidual) const
	Computes position and velocity of the virtual point.

void	testPositiveParam (double value, ISimObjectCreator *creator, std::string valueName)

void	computeElementTension (const double prev, const double curr, double *force)
	test if a parameter is positive, and reports error if not.

void	computeSegmentStructuralJacobian (const double pA, const double pB, const double vA, const double vB, double dFA_dpA, double dFA_dpB, double dFA_dvA, double dFA_dvB) const
	compute structural tension for a single element

Protected Attributes
double	m_cableLength

double	m_cableWeight
	total cable length [m]

double	m_Emodulus
	cable weight [kg/m]

double	m_tensileCrossSectionArea
	Young's modulus of load bearing material [Pa].

double	m_displacementCrossSectionArea
	cross section area of load bearing material [m^2]

double	m_diameter
	displaced fluid volume per meter cable [m^2]

double	m_hydrodynamicDiameter
	cable diameter [m]

double	m_submergedWeight
	effective hydrodynamic diameter [m]

double	m_internalDamping
	weight of cable underwater [kg/m]

int	m_numElements
	structural axial damping. [N*s/m]

double	m_elementMass
	number of elements in the cable [#]

double	m_elementMassInverse
	mass of each element [kg]

double	m_segmentMass
	inverse mass of each element [kg^-1]

double	m_segmentSubmergedMass
	mass of each segment [kg]

double	m_segmentLength
	submerged weight of each element [kg]

double	m_segmentStiffness
	length of spring between elements [m]

int *	m_elementPositionIndex
	spring stiffness [N/m]

int *	m_elementVelocityIndex
	The relative index of the position state in the state array for each element [#].

ISignalPort *	m_PositionA
	The relative index of the velocity state in the state array for each element [#].

ISignalPort *	m_PositionB
	input port. Position of point A [m]

ISignalPort *	m_VelocityA
	input port. Position of point B [m]

ISignalPort *	m_VelocityB
	input port. Velocity of point A [m/s]

ISignalPort *	m_retractedLengthPortA
	input port. Velocity of point B [m/s]

ISignalPort *	m_retractedLengthPortB
	amount of retracted cable at endpoint A [m]

ISignalPort *	m_retractedSpeedPortA
	amount of retracted cable at endpoint B [m]

ISignalPort *	m_retractedSpeedPortB
	retraction rate at endpoint A [m/s]

double	m_endForceA [3]
	retraction rate at endpoint B [m/s]

double	m_endForceB [3]
	reactive force at endpoint A [N]

double	m_nodeForceA [3]
	reactive force at endpoint A [N]

double	m_nodeForceB [3]
	force on first free node at endpoint A [N]

double	m_retractedLengthA
	force on first free node at endpoint A [N]

double	m_retractedLengthB
	amount of retracted cable at endpoint A [m]

int	m_retractedNodesA
	amount of retracted cable at endpoint B [m]

int	m_retractedNodesB
	number of nodes currently on winch A

double	m_virtualPointA [3]
	number of nodes currently on winch B

double	m_virtualPointB [3]
	when cable is winched, the closest free node is attracted towards a ghost point "beyond" the actual endpoint [m]

double	m_virtualPointVelocityA [3]
	when cable is winched, the closest free node is attracted towards a ghost point "beyond" the actual endpoint [m]

double	m_virtualPointVelocityB [3]
	when cable is winched, the closest free node is attracted towards a ghost point "beyond" the actual endpoint [m/s]

double	m_residualA
	when cable is winched, the closest free node is attracted towards a ghost point "beyond" the actual endpoint [m/s]

double	m_residualB
	free length of closest free node [m]

ICommonComputation *	m_computeEndForces
	free length of closest free node [m]

const double *	m_posA
	computation node for endpoint reaction forces

const double *	m_posB
	Position of point A [m].

const double *	m_velA
	Position of point B [m].

const double *	m_velB
	Velocity of point A [m].

environment::EnvironmentProvider *	m_environment
	Velocity of point B [m].

Constructor & Destructor Documentation

◆ CCable()

CCable::CCable	(	const std::string &	simObjectName,
		ISimObjectCreator *const	creator
	)

This constructor performs all initial setup for a point mass simobject. Reading in parameters, setting up communication interface i.e. output ports, input ports, and states, plus additional 'one time only' resource setup.

Parameters

[in]	simObjectName	-> The name of the simobject. Used primarily by superclass constructor
[in]	creator	-> Retrieve parameters. Register states, ports and shared resources

Member Function Documentation

◆ computeSegmentForces()

void CCable::computeSegmentForces	(	const double	T,
		const double *	X,
		const double *	pA,
		const double *	pB,
		const double *	vA,
		const double *	vB,
		double *	FA,
		double *	FB
	)		const

protected

Computes all forces acting on an element

Computes structural and environmental forces acting on an element i.e. the cable length between two cable nodes, and distributes the total force on the two nodes.

Parameters

[in]	T	-> current simulation time
[in]	X	-> current simulation state
[in]	pA	-> position of element A
[in]	pB	-> position of element B
[in]	vA	-> velocity of element A
[in]	vB	-> velocity of element B
[out]	FA	-> force on element A
[out]	FB	-> force on element B

◆ computeSegmentStructuralJacobian()

void CCable::computeSegmentStructuralJacobian	(	const double *	pA,
		const double *	pB,
		const double *	vA,
		const double *	vB,
		double *	dFA_dpA,
		double *	dFA_dpB,
		double *	dFA_dvA,
		double *	dFA_dvB
	)		const

protected

Computes the Jacobian contributions from a single cable segment's structural forces (tension + damping). Fills 4 matrices of size [3 x 3]: dFA/dpA, dFA/dpB, dFA/dvA, dFA/dvB. dFB = -dFA by Newton's third law.

◆ computeVirtualPoint()

void CCable::computeVirtualPoint	(	const double *const	target,
		const double *const	point,
		const double *const	targetVel,
		const double *const	pointVel,
		double *	virtualPoint,
		double *	virtualPointVel,
		double	residual,
		double	dResidual
	)		const

protected

Winch functionality is implemented by pulling the closest free node towards a virtual point rather than the actual endpoint.

Parameters

[in]	target	-> actual endpoint position
[in]	point	-> position of free node
[in]	targetVel	-> actual endpoint velocity
[in]	pointVel	-> velocity of free node
[in]	residual	-> free element length
[in]	dResidual	-> rate of change in free element length
[out]	virtualPoint	-> position of virtual point
[out]	virtualPointVel	-> velocity of virtual point

◆ InitialConditionSetup()

void CCable::InitialConditionSetup	(	const double	T,
		const double *const	currentIC,
		double *const	updatedIC,
		ISimObjectCreator *const	creator
	)

Sets initial conditions based on the value of input ports. Element positions of free nodes are equally distributed between endpoint positions. Element Velocity are linearly interpolated between endpoint velocity

Parameters

[in]	T	-> The time at the beginning of the simulation. Usually but not necessarily zero
[in]	currentIC	-> Array of initial conditions. If the value is QNAN, the value is not set yet and can be set by the SimObject, otherwise the value is set, and can not be changed. Trying to change an already set value will trigger an error
[in]	creator	-> Report back to creator if output port are not ready
[out]	updatedIC	-> Array of ONAN. Any initial condition that are ready to be set, should be written to this array.

◆ OdeFcn()

void CCable::OdeFcn	(	const double	T,
		const double *const	X,
		double *const	XDot
	)		const

Computes object derivatives as a function of time, states and input ports

Returns state derivatives. Velocity as derivative of position, external-force/mass and gravity as derivative of velocity. Adjusts position of not-free nodes.

Parameters

[in]	T	-> current simulation time
[in]	X	-> current simulation state
[out]	XDot	-> state derivatives
[in]	bIsMajorTimeStep	-> Is this a major time step?

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

/update_root/webfhsim/reloadrepos/fhsim_base/src/cable/Cable.h

Public Member Functions

Protected Member Functions

Protected Attributes

Constructor & Destructor Documentation

◆ CCable()

Member Function Documentation

◆ computeSegmentForces()

◆ computeSegmentStructuralJacobian()

◆ computeVirtualPoint()

◆ InitialConditionSetup()

◆ OdeFcn()