Time-derivative estimation by backward differencing. JointAccelerationBackwardDifference uses backward differencing to estimate the second time derivative of the joint state. More...

#include <joint_acceleration_backward_difference.h>

Inheritance diagram for exotica::JointAccelerationBackwardDifference:

[legend]

Public Member Functions
void	AssignScene (ScenePtr scene) override

void	SetPreviousJointState (Eigen::VectorXdRefConst joint_state)
	Logs previous joint state. SetPreviousJointState must be called after solve is called in a Python/C++ script is called to ensure the time-derivatives are appropriately approximated. Each previous joint state is pushed back by column and the given joint_state is placed in q_.col(0). Finally, we compute the new qbd_. More...

int	TaskSpaceDim () override

void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRef phi) override

void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRef phi, Eigen::MatrixXdRef jacobian) override

Public Member Functions inherited from exotica::TaskMap
std::vector< KinematicFrameRequest >	GetFrames () const

virtual std::vector< TaskVectorEntry >	GetLieGroupIndices ()

virtual void	InstantiateBase (const Initializer &init)

virtual void	PreUpdate ()

virtual int	TaskSpaceJacobianDim ()

virtual void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRefConst u, Eigen::VectorXdRef phi, Eigen::MatrixXdRef dphi_dx, Eigen::MatrixXdRef dphi_du)

virtual void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRefConst u, Eigen::VectorXdRef phi)

virtual void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRefConst u, Eigen::VectorXdRef phi, Eigen::MatrixXdRef dphi_dx, Eigen::MatrixXdRef dphi_du, HessianRef ddphi_ddx, HessianRef ddphi_ddu, HessianRef ddphi_dxdu)

virtual void	Update (Eigen::VectorXdRefConst q, Eigen::VectorXdRef phi, Eigen::MatrixXdRef jacobian, HessianRef hessian)

Public Member Functions inherited from exotica::Object
std::string	GetObjectName ()

void	InstantiateObject (const Initializer &init)

	Object ()

virtual std::string	Print (const std::string &prepend) const

virtual std::string	type () const

virtual	~Object ()

Public Member Functions inherited from exotica::InstantiableBase
	InstantiableBase ()=default

virtual	~InstantiableBase ()=default

Public Member Functions inherited from exotica::Instantiable< JointAccelerationBackwardDifferenceInitializer >
std::vector< Initializer >	GetAllTemplates () const override

Initializer	GetInitializerTemplate () override

const JointAccelerationBackwardDifferenceInitializer &	GetParameters () const

virtual void	Instantiate (const JointAccelerationBackwardDifferenceInitializer &init)

void	InstantiateInternal (const Initializer &init) override

Private Attributes
Eigen::Vector2d	backward_difference_params_
	Binomial cooeficient parameters. More...

Eigen::MatrixXd	I_
	Identity matrix. More...

int	N_
	Number of dofs for robot. More...

Eigen::MatrixXd	q_
	Log of previous two joint states. More...

Eigen::VectorXd	qbd_
	x+qbd_ is a simplifed estimate of the second time derivative. More...

Additional Inherited Members
Public Attributes inherited from exotica::TaskMap
int	id

bool	is_used

std::vector< KinematicSolution >	kinematics

int	length

int	length_jacobian

int	start

int	start_jacobian

Public Attributes inherited from exotica::Object
bool	debug_

std::string	ns_

std::string	object_name_

Protected Attributes inherited from exotica::TaskMap
std::vector< KinematicFrameRequest >	frames_

ScenePtr	scene_

Protected Attributes inherited from exotica::Instantiable< JointAccelerationBackwardDifferenceInitializer >
JointAccelerationBackwardDifferenceInitializer	parameters_

Detailed Description

Time-derivative estimation by backward differencing. JointAccelerationBackwardDifference uses backward differencing to estimate the second time derivative of the joint state.

For more information see: http://mathworld.wolfram.com/BackwardDifference.html

Here, x+qbd_ represents the simplified estimate of the second time derivative.

Definition at line 48 of file joint_acceleration_backward_difference.h.

Member Function Documentation

void exotica::JointAccelerationBackwardDifference::AssignScene ( ScenePtr scene )

overridevirtual

Reimplemented from exotica::TaskMap.

Definition at line 36 of file joint_acceleration_backward_difference.cpp.

void exotica::JointAccelerationBackwardDifference::SetPreviousJointState ( Eigen::VectorXdRefConst joint_state )

Logs previous joint state. SetPreviousJointState must be called after solve is called in a Python/C++ script is called to ensure the time-derivatives are appropriately approximated. Each previous joint state is pushed back by column and the given joint_state is placed in q_.col(0). Finally, we compute the new qbd_.

Definition at line 69 of file joint_acceleration_backward_difference.cpp.

int exotica::JointAccelerationBackwardDifference::TaskSpaceDim ( )

overridevirtual

Implements exotica::TaskMap.

Definition at line 101 of file joint_acceleration_backward_difference.cpp.