exotica::JointAccelerationBackwardDifference Class Reference

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:

Collaboration diagram for exotica::JointAccelerationBackwardDifference:

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...
void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRef phi) override
void	Update (Eigen::VectorXdRefConst x, Eigen::VectorXdRef phi, Eigen::MatrixXdRef jacobian) override
int	TaskSpaceDim () override
Public Member Functions inherited from exotica::TaskMap
virtual void	InstantiateBase (const Initializer &init)
virtual void	Update (Eigen::VectorXdRefConst q, Eigen::VectorXdRef phi, Eigen::MatrixXdRef jacobian, HessianRef hessian)
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)
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 int	TaskSpaceJacobianDim ()
virtual void	PreUpdate ()
virtual std::vector< TaskVectorEntry >	GetLieGroupIndices ()
std::vector< KinematicFrameRequest >	GetFrames () const
Public Member Functions inherited from exotica::Object
	Object ()
virtual	~Object ()
virtual std::string	type () const
	Type Information wrapper: must be virtual so that it is polymorphic... More...
std::string	GetObjectName ()
void	InstantiateObject (const Initializer &init)
virtual std::string	Print (const std::string &prepend) const
Public Member Functions inherited from exotica::InstantiableBase
	InstantiableBase ()=default
virtual	~InstantiableBase ()=default
virtual std::vector< Initializer >	GetAllTemplates () const =0
Public Member Functions inherited from exotica::Instantiable< JointAccelerationBackwardDifferenceInitializer >
void	InstantiateInternal (const Initializer &init) override
Initializer	GetInitializerTemplate () override
std::vector< Initializer >	GetAllTemplates () const override
virtual void	Instantiate (const JointAccelerationBackwardDifferenceInitializer &init)
const JointAccelerationBackwardDifferenceInitializer &	GetParameters () const

Private Attributes
int	N_
	Number of dofs for robot. More...
Eigen::Vector2d	backward_difference_params_
	Binomial cooeficient parameters. 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...
Eigen::MatrixXd	I_
	Identity matrix. More...

Additional Inherited Members
Public Attributes inherited from exotica::TaskMap
std::vector< KinematicSolution >	kinematics = std::vector<KinematicSolution>(1)
int	id = -1
int	start = -1
int	length = -1
int	start_jacobian = -1
int	length_jacobian = -1
bool	is_used = false
Public Attributes inherited from exotica::Object
std::string	ns_
std::string	object_name_
bool	debug_
Protected Attributes inherited from exotica::TaskMap
std::vector< KinematicFrameRequest >	frames_
ScenePtr	scene_ = nullptr
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.

Member Function Documentation

AssignScene()

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

overridevirtual

Reimplemented from exotica::TaskMap.

SetPreviousJointState()

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_.

TaskSpaceDim()

int exotica::JointAccelerationBackwardDifference::TaskSpaceDim ( )

overridevirtual

Implements exotica::TaskMap.

Update() [1/2]

void exotica::JointAccelerationBackwardDifference::Update ( Eigen::VectorXdRefConst  x, Eigen::VectorXdRef  phi  )

overridevirtual

Implements exotica::TaskMap.

Update() [2/2]

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

overridevirtual

Reimplemented from exotica::TaskMap.

Member Data Documentation

backward_difference_params_

Eigen::Vector2d exotica::JointAccelerationBackwardDifference::backward_difference_params_

private

Binomial cooeficient parameters.

I_

Eigen::MatrixXd exotica::JointAccelerationBackwardDifference::I_

private

Identity matrix.

N_

int exotica::JointAccelerationBackwardDifference::N_

private

Number of dofs for robot.

q_

Eigen::MatrixXd exotica::JointAccelerationBackwardDifference::q_

private

Log of previous two joint states.

qbd_

Eigen::VectorXd exotica::JointAccelerationBackwardDifference::qbd_

private

x+qbd_ is a simplifed estimate of the second time derivative.

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

• /tmp/exotica/exotations/exotica_core_task_maps/include/exotica_core_task_maps/joint_acceleration_backward_difference.h