Standard RK integrator. More...

#include <crocoddyl/core/integrator/rk.hpp>

Public Types
typedef ActionDataAbstractTpl< Scalar >	ActionDataAbstract

typedef IntegratedActionModelAbstractTpl< Scalar >	Base

typedef ControlParametrizationModelAbstractTpl< Scalar >	ControlParametrizationModelAbstract

typedef IntegratedActionDataRKTpl< Scalar >	Data

typedef DifferentialActionModelAbstractTpl< Scalar >	DifferentialActionModelAbstract

typedef MathBaseTpl< Scalar >	MathBase

typedef MathBase::MatrixXs	MatrixXs

typedef MathBase::VectorXs	VectorXs

Public Member Functions
	IntegratedActionModelRKTpl (boost::shared_ptr< DifferentialActionModelAbstract > model, boost::shared_ptr< ControlParametrizationModelAbstract > control, const RKType rktype, const Scalar time_step=Scalar(1e-3), const bool with_cost_residual=true)
	Initialize the RK integrator. More...

	IntegratedActionModelRKTpl (boost::shared_ptr< DifferentialActionModelAbstract > model, const RKType rktype, const Scalar time_step=Scalar(1e-3), const bool with_cost_residual=true)
	Initialize the RK integrator. More...

virtual void	calc (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x)
	Integrate the total cost value for nodes that depends only on the state using RK scheme. More...

virtual void	calc (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Integrate the differential action model using RK scheme. More...

virtual void	calcDiff (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x)
	Compute the partial derivatives of the cost. More...

virtual void	calcDiff (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the partial derivatives of the RK integrator. More...

virtual bool	checkData (const boost::shared_ptr< ActionDataAbstract > &data)
	Checks that a specific data belongs to this model.

virtual boost::shared_ptr< ActionDataAbstract >	createData ()
	Create the RK integrator data. More...

std::size_t	get_ni () const
	Return the number of nodes of the integrator.

virtual void	print (std::ostream &os) const
	Print relevant information of the RK integrator model. More...

virtual void	quasiStatic (const boost::shared_ptr< ActionDataAbstract > &data, Eigen::Ref< VectorXs > u, const Eigen::Ref< const VectorXs > &x, const std::size_t maxiter=100, const Scalar tol=Scalar(1e-9))
	Computes the quasic static commands. More...

Public Attributes
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar

Protected Attributes
boost::shared_ptr< ControlParametrizationModelAbstract >	control_
	Model of the control parametrization.

boost::shared_ptr< DifferentialActionModelAbstract >	differential_
	< Control parametrization

std::size_t	nu_
	< Differential action model

boost::shared_ptr< StateAbstract >	state_
	< Dimension of the control

Scalar	time_step2_
	< Model of the state

Scalar	time_step_
	< Square of the time step used for integration

bool	with_cost_residual_
	< Time step used for integration

Detailed Description

template<typename _Scalar>
class crocoddyl::IntegratedActionModelRKTpl< _Scalar >

Standard RK integrator.

It applies a standard RK integration schemes to a differential (i.e., continuous time) action model. The available integrators are: RK2, RK3, and RK4.

This standard RK scheme introduces also the possibility to parametrize the control trajectory inside an integration step, for instance using polynomials. This requires introducing some notation to clarify the difference between the control inputs of the differential model and the control inputs to the integrated model. We have decided to use \(\mathbf{w}\) to refer to the control inputs of the differential model and \(\mathbf{u}\) for the control inputs of the integrated action model.

See also: IntegratedActionModelAbstractTpl, calc(), calcDiff(), createData()

Definition at line 65 of file fwd.hpp.

Constructor & Destructor Documentation

◆ IntegratedActionModelRKTpl() [1/2]

IntegratedActionModelRKTpl	(	boost::shared_ptr< DifferentialActionModelAbstract >	model,
		boost::shared_ptr< ControlParametrizationModelAbstract >	control,
		const RKType	rktype,
		const Scalar	time_step = `Scalar(1e-3)`,
		const bool	with_cost_residual = `true`
	)

Initialize the RK integrator.

Parameters

[in]	model	Differential action model
[in]	control	Control parametrization
[in]	rktype	Type of RK integrator
[in]	time_step	Step time (default 1e-3)
[in]	with_cost_residual	Compute cost residual (default true)

◆ IntegratedActionModelRKTpl() [2/2]

IntegratedActionModelRKTpl	(	boost::shared_ptr< DifferentialActionModelAbstract >	model,
		const RKType	rktype,
		const Scalar	time_step = `Scalar(1e-3)`,
		const bool	with_cost_residual = `true`
	)

Initialize the RK integrator.

This initialization uses ControlParametrizationPolyZeroTpl for the control parametrization.

Parameters

[in]	model	Differential action model
[in]	rktype	Type of RK integrator
[in]	time_step	Step time (default 1e-3)
[in]	with_cost_residual	Compute cost residual (default true)

Member Function Documentation

◆ calc() [1/2]

virtual void calc	(	const boost::shared_ptr< ActionDataAbstract > &	data,
		const Eigen::Ref< const VectorXs > &	x,
		const Eigen::Ref< const VectorXs > &	u
	)

virtual

Integrate the differential action model using RK scheme.

Parameters

[in]	data	RK integrator data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

◆ calc() [2/2]

virtual void calc	(	const boost::shared_ptr< ActionDataAbstract > &	data,
		const Eigen::Ref< const VectorXs > &	x
	)

virtual

Integrate the total cost value for nodes that depends only on the state using RK scheme.

It computes the total cost and defines the next state as the current one. This function is used in the terminal nodes of an optimal control problem.

Parameters

[in]	data	RK integrator data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

◆ calcDiff() [1/2]

virtual void calcDiff	(	const boost::shared_ptr< ActionDataAbstract > &	data,
		const Eigen::Ref< const VectorXs > &	x,
		const Eigen::Ref< const VectorXs > &	u
	)

virtual

Compute the partial derivatives of the RK integrator.

Parameters

[in]	data	RK integrator data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

◆ calcDiff() [2/2]

virtual void calcDiff	(	const boost::shared_ptr< ActionDataAbstract > &	data,
		const Eigen::Ref< const VectorXs > &	x
	)

virtual

Compute the partial derivatives of the cost.

It updates the derivatives of the cost function with respect to the state only. This function is used in the terminal nodes of an optimal control problem.

Parameters

[in]	data	RK integrator data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

◆ createData()

virtual boost::shared_ptr<ActionDataAbstract> createData ( )

virtual

Create the RK integrator data.

Returns: the RK integrator data

◆ quasiStatic()

virtual void quasiStatic	(	const boost::shared_ptr< ActionDataAbstract > &	data,
		Eigen::Ref< VectorXs >	u,
		const Eigen::Ref< const VectorXs > &	x,
		const std::size_t	maxiter = `100`,
		const Scalar	tol = `Scalar(1e-9)`
	)

virtual

Computes the quasic static commands.

The quasic static commands are the ones produced for a the reference posture as an equilibrium point, i.e. for \(\mathbf{f^q_x}\delta\mathbf{q}+\mathbf{f_u}\delta\mathbf{u}=\mathbf{0}\)

Parameters

[in]	data	RK integrator data
[out]	u	Quasic static commands
[in]	x	State point (velocity has to be zero)
[in]	maxiter	Maximum allowed number of iterations
[in]	tol	Tolerance

◆ print()

virtual void print ( std::ostream & os ) const

virtual

Print relevant information of the RK integrator model.

Parameters

[out] os Output stream object

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

include/crocoddyl/core/fwd.hpp
include/crocoddyl/core/integrator/rk.hpp

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Detailed Description

template<typename _Scalar> class crocoddyl::IntegratedActionModelRKTpl< _Scalar >

Constructor & Destructor Documentation

◆ IntegratedActionModelRKTpl() [1/2]

◆ IntegratedActionModelRKTpl() [2/2]

Member Function Documentation

◆ calc() [1/2]

◆ calc() [2/2]

◆ calcDiff() [1/2]

◆ calcDiff() [2/2]

◆ createData()

◆ quasiStatic()

◆ print()

template<typename _Scalar>
class crocoddyl::IntegratedActionModelRKTpl< _Scalar >