Robot Dynamics Library: RobotDynamics::ConstraintSet Struct Reference

Structure that contains both constraint information and workspace memory. More...

#include <Contacts.hpp>

Public Member Functions
	ConstraintSet ()

unsigned int	addConstraint (unsigned int body_id, const Math::Vector3d &body_point, const Math::Vector3d &world_normal, const char *constraint_name=NULL, double normal_acceleration=0.)
	Adds a constraint to the constraint set. More...

ConstraintSet	Copy ()
	Copies the constraints and resets its ConstraintSet::bound flag. More...

void	setSolver (Math::LinearSolver solver)
	Specifies which method should be used for solving undelying linear systems. More...

bool	bind (const Model &model)
	Initializes and allocates memory for the constraint set. More...

size_t	size () const
	Returns the number of constraints. More...

void	clear ()
	Clears all variables in the constraint set. More...

Public Attributes
Math::LinearSolver	linear_solver
	Method that should be used to solve internal linear systems. More...

bool	bound
	Whether the constraint set was bound to a model (mandatory!). More...

std::vector< std::string >	name

std::vector< unsigned int >	body

std::vector< Math::Vector3d >	point

std::vector< Math::Vector3d >	normal

Math::VectorNd	acceleration

Math::VectorNd	force

Math::VectorNd	impulse

Math::VectorNd	v_plus

Math::MatrixNd	H
	Workspace for the joint space inertia matrix. More...

Math::VectorNd	C
	Workspace for the coriolis forces. More...

Math::VectorNd	gamma
	Workspace of the lower part of b. More...

Math::MatrixNd	G

Math::MatrixNd	A
	Workspace for the Lagrangian left-hand-side matrix. More...

Math::VectorNd	b
	Workspace for the Lagrangian right-hand-side. More...

Math::VectorNd	x
	Workspace for the Lagrangian solution. More...

Eigen::HouseholderQR< Math::MatrixNd >	GT_qr
	Workspace for the QR decomposition of the null-space method. More...

Math::MatrixNd	GT_qr_Q

Math::MatrixNd	Y

Math::MatrixNd	Z

Math::VectorNd	qddot_y

Math::VectorNd	qddot_z

Math::MatrixNd	K
	Workspace for the Inverse Articulated-Body Inertia. More...

Math::VectorNd	a
	Workspace for the accelerations of due to the test forces. More...

Math::VectorNd	QDDot_t
	Workspace for the test accelerations. More...

Math::VectorNd	QDDot_0
	Workspace for the default accelerations. More...

Math::SpatialForceV	f_t
	Workspace for the test forces. More...

Math::SpatialForceV	f_ext_constraints
	Workspace for the actual spatial forces. More...

std::vector< Math::Vector3d >	point_accel_0
	Workspace for the default point accelerations. More...

Math::SpatialForceV	d_pA
	Workspace for the bias force due to the test force. More...

std::vector< Math::SpatialVector >	d_a
	Workspace for the acceleration due to the test force. More...

Math::VectorNd	d_u

std::vector< Math::SpatialMatrix >	d_IA
	Workspace for the inertia when applying constraint forces. More...

std::vector< Math::SpatialVector >	d_U
	Workspace when applying constraint forces. More...

Math::VectorNd	d_d
	Workspace when applying constraint forces. More...

std::vector< Math::Vector3d >	d_multdof3_u

Detailed Description

Structure that contains both constraint information and workspace memory.

This structure is used to reduce the amount of memory allocations that are needed when computing constraint forces.

The ConstraintSet has to be bound to a model using ConstraintSet::bind() before it can be used in forwardDynamicsContacts .

Constructor & Destructor Documentation

◆ ConstraintSet()

RobotDynamics::ConstraintSet::ConstraintSet ( )

inline

Member Function Documentation

◆ addConstraint()

unsigned int RobotDynamics::ConstraintSet::addConstraint	(	unsigned int	body_id,
		const Math::Vector3d &	body_point,
		const Math::Vector3d &	world_normal,
		const char *	constraint_name = `NULL`,
		double	normal_acceleration = `0.`
	)

Adds a constraint to the constraint set.

Parameters

body_id	the body which is affected directly by the constraint
body_point	the point that is constrained relative to the contact body
world_normal	the normal along the constraint acts (in base coordinates)
constraint_name	a human readable name (optional, default: NULL)
normal_acceleration	the acceleration of the contact along the normal (optional, default: 0.)

◆ bind()

bool RobotDynamics::ConstraintSet::bind ( const Model & model )

Initializes and allocates memory for the constraint set.

This function allocates memory for temporary values and matrices that are required for contact force computation. Both model and constraint set must not be changed after a binding as the required memory is dependent on the model size (i.e. the number of bodies and degrees of freedom) and the number of constraints in the Constraint set.

The values of ConstraintSet::acceleration may still be modified after the set is bound to the model.

◆ clear()

void RobotDynamics::ConstraintSet::clear ( )

Clears all variables in the constraint set.

◆ Copy()

ConstraintSet RobotDynamics::ConstraintSet::Copy ( )

inline

Copies the constraints and resets its ConstraintSet::bound flag.

◆ setSolver()

void RobotDynamics::ConstraintSet::setSolver ( Math::LinearSolver solver )

inline

Specifies which method should be used for solving undelying linear systems.

◆ size()

size_t RobotDynamics::ConstraintSet::size ( ) const

inline

Returns the number of constraints.

Member Data Documentation

◆ A

Math::MatrixNd RobotDynamics::ConstraintSet::A

Workspace for the Lagrangian left-hand-side matrix.

◆ a

Math::VectorNd RobotDynamics::ConstraintSet::a

Workspace for the accelerations of due to the test forces.

◆ acceleration

Math::VectorNd RobotDynamics::ConstraintSet::acceleration

Enforced accelerations of the contact points along the contact normal.

◆ b

Math::VectorNd RobotDynamics::ConstraintSet::b

Workspace for the Lagrangian right-hand-side.

◆ body

std::vector<unsigned int> RobotDynamics::ConstraintSet::body

◆ bound

bool RobotDynamics::ConstraintSet::bound

Whether the constraint set was bound to a model (mandatory!).

◆ C

Math::VectorNd RobotDynamics::ConstraintSet::C

Workspace for the coriolis forces.

◆ d_a

std::vector<Math::SpatialVector> RobotDynamics::ConstraintSet::d_a

Workspace for the acceleration due to the test force.

◆ d_d

Math::VectorNd RobotDynamics::ConstraintSet::d_d

Workspace when applying constraint forces.

◆ d_IA

std::vector<Math::SpatialMatrix> RobotDynamics::ConstraintSet::d_IA

Workspace for the inertia when applying constraint forces.

◆ d_multdof3_u

std::vector<Math::Vector3d> RobotDynamics::ConstraintSet::d_multdof3_u

◆ d_pA

Math::SpatialForceV RobotDynamics::ConstraintSet::d_pA

Workspace for the bias force due to the test force.

◆ d_u

Math::VectorNd RobotDynamics::ConstraintSet::d_u

◆ d_U

std::vector<Math::SpatialVector> RobotDynamics::ConstraintSet::d_U

Workspace when applying constraint forces.

◆ f_ext_constraints

Math::SpatialForceV RobotDynamics::ConstraintSet::f_ext_constraints

Workspace for the actual spatial forces.

◆ f_t

Math::SpatialForceV RobotDynamics::ConstraintSet::f_t

Workspace for the test forces.

◆ force

Math::VectorNd RobotDynamics::ConstraintSet::force

Actual constraint forces along the contact normals.

◆ G

Math::MatrixNd RobotDynamics::ConstraintSet::G

◆ gamma

Math::VectorNd RobotDynamics::ConstraintSet::gamma

Workspace of the lower part of b.

◆ GT_qr

Eigen::HouseholderQR<Math::MatrixNd> RobotDynamics::ConstraintSet::GT_qr

Workspace for the QR decomposition of the null-space method.

◆ GT_qr_Q

Math::MatrixNd RobotDynamics::ConstraintSet::GT_qr_Q

◆ H

Math::MatrixNd RobotDynamics::ConstraintSet::H

Workspace for the joint space inertia matrix.

◆ impulse

Math::VectorNd RobotDynamics::ConstraintSet::impulse

Actual constraint impulses along the contact normals.

◆ K

Math::MatrixNd RobotDynamics::ConstraintSet::K

Workspace for the Inverse Articulated-Body Inertia.

◆ linear_solver

Math::LinearSolver RobotDynamics::ConstraintSet::linear_solver

Method that should be used to solve internal linear systems.

◆ name

std::vector<std::string> RobotDynamics::ConstraintSet::name

◆ normal

std::vector<Math::Vector3d> RobotDynamics::ConstraintSet::normal

◆ point

std::vector<Math::Vector3d> RobotDynamics::ConstraintSet::point

◆ point_accel_0

std::vector<Math::Vector3d> RobotDynamics::ConstraintSet::point_accel_0

Workspace for the default point accelerations.

◆ QDDot_0

Math::VectorNd RobotDynamics::ConstraintSet::QDDot_0

Workspace for the default accelerations.

◆ QDDot_t

Math::VectorNd RobotDynamics::ConstraintSet::QDDot_t

Workspace for the test accelerations.

◆ qddot_y

Math::VectorNd RobotDynamics::ConstraintSet::qddot_y

◆ qddot_z

Math::VectorNd RobotDynamics::ConstraintSet::qddot_z

◆ v_plus

Math::VectorNd RobotDynamics::ConstraintSet::v_plus

The velocities we want to have along the contact normals after calling ComputeContactImpulsesLagrangian

◆ x

Math::VectorNd RobotDynamics::ConstraintSet::x

Workspace for the Lagrangian solution.

◆ Y

Math::MatrixNd RobotDynamics::ConstraintSet::Y

◆ Z

Math::MatrixNd RobotDynamics::ConstraintSet::Z

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

rdl_dynamics/include/rdl_dynamics/Contacts.hpp
rdl_dynamics/src/Contacts.cpp

Public Member Functions

Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ConstraintSet()

Member Function Documentation

◆ addConstraint()

◆ bind()

◆ clear()

◆ Copy()

◆ setSolver()

◆ size()

Member Data Documentation

◆ A

◆ a

◆ acceleration

◆ b

◆ body

◆ bound

◆ C

◆ d_a

◆ d_d

◆ d_IA

◆ d_multdof3_u

◆ d_pA

◆ d_u

◆ d_U

◆ f_ext_constraints

◆ f_t

◆ force

◆ G

◆ gamma

◆ GT_qr

◆ GT_qr_Q

◆ H

◆ impulse

◆ K

◆ linear_solver

◆ name

◆ normal

◆ point

◆ point_accel_0

◆ QDDot_0

◆ QDDot_t

◆ qddot_y

◆ qddot_z

◆ v_plus

◆ x

◆ Y

◆ Z