Differential action model for free forward dynamics in multibody systems. More...

#include <free-fwddyn.hpp>

Inheritance diagram for DifferentialActionModelFreeFwdDynamicsTpl< _Scalar >:

Public Types
typedef ActuationModelAbstractTpl< Scalar >	ActuationModelAbstract

typedef DifferentialActionModelAbstractTpl< Scalar >	Base

typedef ConstraintModelManagerTpl< Scalar >	ConstraintModelManager

typedef CostModelSumTpl< Scalar >	CostModelSum

typedef DifferentialActionDataFreeFwdDynamicsTpl< Scalar >	Data

typedef DifferentialActionDataAbstractTpl< Scalar >	DifferentialActionDataAbstract

typedef MathBaseTpl< Scalar >	MathBase

typedef MathBase::MatrixXs	MatrixXs

typedef StateMultibodyTpl< Scalar >	StateMultibody

typedef MathBase::VectorXs	VectorXs

Public Types inherited from DifferentialActionModelAbstractTpl< _Scalar >
typedef DifferentialActionDataAbstractTpl< Scalar >	DifferentialActionDataAbstract

typedef MathBaseTpl< Scalar >	MathBase

typedef MathBase::MatrixXs	MatrixXs

typedef StateAbstractTpl< Scalar >	StateAbstract

typedef MathBase::VectorXs	VectorXs

Public Member Functions
	DifferentialActionModelFreeFwdDynamicsTpl (boost::shared_ptr< StateMultibody > state, boost::shared_ptr< ActuationModelAbstract > actuation, boost::shared_ptr< CostModelSum > costs, boost::shared_ptr< ConstraintModelManager > constraints=nullptr)

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

virtual void	calc (const boost::shared_ptr< DifferentialActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the system acceleration, and cost value. More...

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

virtual void	calcDiff (const boost::shared_ptr< DifferentialActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the derivatives of the contact dynamics, and cost function. More...

virtual bool	checkData (const boost::shared_ptr< DifferentialActionDataAbstract > &data)
	Check that the given data belongs to the free forward-dynamics data.

virtual boost::shared_ptr< DifferentialActionDataAbstract >	createData ()
	Create the free forward-dynamics data. More...

const boost::shared_ptr< ActuationModelAbstract > &	get_actuation () const
	Return the actuation model.

const VectorXs &	get_armature () const
	Return the armature vector.

const boost::shared_ptr< ConstraintModelManager > &	get_constraints () const
	Return the constraint model manager.

const boost::shared_ptr< CostModelSum > &	get_costs () const
	Return the cost model.

virtual const VectorXs &	get_g_lb () const
	Return the lower bound of the inequality constraints.

virtual const VectorXs &	get_g_ub () const
	Return the upper bound of the inequality constraints.

virtual std::size_t	get_ng () const
	Return the number of inequality constraints.

virtual std::size_t	get_nh () const
	Return the number of equality constraints.

pinocchio::ModelTpl< Scalar > &	get_pinocchio () const
	Return the Pinocchio model.

virtual void	print (std::ostream &os) const
	Print relevant information of the free forward-dynamics model. More...

virtual void	quasiStatic (const boost::shared_ptr< DifferentialActionDataAbstract > &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...

void	set_armature (const VectorXs &armature)
	Modify the armature vector.

Public Member Functions inherited from DifferentialActionModelAbstractTpl< _Scalar >
	DifferentialActionModelAbstractTpl (boost::shared_ptr< StateAbstract > state, const std::size_t nu, const std::size_t nr=0, const std::size_t ng=0, const std::size_t nh=0)
	Initialize the differential action model. More...

bool	get_has_control_limits () const
	Indicates if there are defined control limits.

std::size_t	get_nr () const
	Return the dimension of the cost-residual vector.

std::size_t	get_nu () const
	Return the dimension of the control input.

const boost::shared_ptr< StateAbstract > &	get_state () const
	Return the state.

const VectorXs &	get_u_lb () const
	Return the control lower bound.

const VectorXs &	get_u_ub () const
	Return the control upper bound.

VectorXs	quasiStatic_x (const boost::shared_ptr< DifferentialActionDataAbstract > &data, const VectorXs &x, const std::size_t maxiter=100, const Scalar tol=Scalar(1e-9))

void	set_g_lb (const VectorXs &g_lb)
	Modify the lower bound of the inequality constraints.

void	set_g_ub (const VectorXs &g_ub)
	Modify the upper bound of the inequality constraints.

void	set_u_lb (const VectorXs &u_lb)
	Modify the control lower bounds.

void	set_u_ub (const VectorXs &u_ub)
	Modify the control upper bounds.

Public Attributes
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar

Public Attributes inherited from DifferentialActionModelAbstractTpl< _Scalar >
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar

Protected Attributes
VectorXs	g_lb_
	Lower bound of the inequality constraints.

VectorXs	g_ub_
	< Lower bound of the inequality constraints

std::size_t	nu_
	< Upper bound of the inequality constraints

boost::shared_ptr< StateAbstract >	state_
	< Control dimension

Protected Attributes inherited from DifferentialActionModelAbstractTpl< _Scalar >
VectorXs	g_lb_
	Lower bound of the inequality constraints.

VectorXs	g_ub_
	Lower bound of the inequality constraints.

bool	has_control_limits_

std::size_t	ng_
	Number of inequality constraints.

std::size_t	nh_
	Number of equality constraints.

std::size_t	nr_
	Dimension of the cost residual.

std::size_t	nu_
	Control dimension.

boost::shared_ptr< StateAbstract >	state_
	Model of the state.

VectorXs	u_lb_
	Lower control limits.

VectorXs	u_ub_
	Upper control limits.

VectorXs	unone_
	Neutral state.

Additional Inherited Members
Protected Member Functions inherited from DifferentialActionModelAbstractTpl< _Scalar >
void	update_has_control_limits ()
	Update the status of the control limits (i.e. if there are defined limits)

Detailed Description

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

Differential action model for free forward dynamics in multibody systems.

This class implements free forward dynamics, i.e.,

\[ \mathbf{M}\dot{\mathbf{v}} + \mathbf{h}(\mathbf{q},\mathbf{v}) = \boldsymbol{\tau}, \]

where \(\mathbf{q}\in Q\), \(\mathbf{v}\in\mathbb{R}^{nv}\) are the configuration point and generalized velocity (its tangent vector), respectively; \(\boldsymbol{\tau}\) is the torque inputs and \(\mathbf{h}(\mathbf{q},\mathbf{v})\) are the Coriolis effect and gravity field.

The derivatives of the system acceleration is computed efficiently based on the analytical derivatives of Articulate Body Algorithm (ABA) as described in [carpentier-rss18].

The stack of cost functions is implemented in CostModelSumTpl. The computation of the free forward dynamics and its derivatives are carrying out inside calc() and calcDiff() functions, respectively. It is also important to remark that calcDiff() computes the derivatives using the latest stored values by calc(). Thus, we need to run calc() first.

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

Definition at line 59 of file free-fwddyn.hpp.

Member Function Documentation

◆ calc() [1/2]

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

virtual

Compute the system acceleration, and cost value.

It computes the system acceleration using the free forward-dynamics.

Parameters

[in]	data	Free forward-dynamics data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

Implements DifferentialActionModelAbstractTpl< _Scalar >.

◆ calc() [2/2]

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

virtual

Reimplemented from DifferentialActionModelAbstractTpl< _Scalar >.

◆ calcDiff() [1/2]

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

virtual

Compute the derivatives of the contact dynamics, and cost function.

Parameters

[in]	data	Free forward-dynamics data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

Implements DifferentialActionModelAbstractTpl< _Scalar >.

◆ calcDiff() [2/2]

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

virtual

Reimplemented from DifferentialActionModelAbstractTpl< _Scalar >.

◆ createData()

virtual boost::shared_ptr<DifferentialActionDataAbstract> createData ( )

virtual

Create the free forward-dynamics data.

Returns: free forward-dynamics data

Reimplemented from DifferentialActionModelAbstractTpl< _Scalar >.

◆ quasiStatic()

virtual void quasiStatic	(	const boost::shared_ptr< DifferentialActionDataAbstract > &	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 \(\mathbf{f}(\mathbf{q},\mathbf{v}=\mathbf{0},\mathbf{u})=\mathbf{0}\)

Parameters

[in]	data	Differential action 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

Reimplemented from DifferentialActionModelAbstractTpl< _Scalar >.

◆ print()

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

virtual

Print relevant information of the free forward-dynamics model.

Parameters

[out] os Output stream object

Reimplemented from DifferentialActionModelAbstractTpl< _Scalar >.

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

/root/robotpkg/optimization/py-crocoddyl/work/crocoddyl-2.1.0/include/crocoddyl/multibody/actions/free-fwddyn.hpp

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Additional Inherited Members

Detailed Description

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

Member Function Documentation

◆ calc() [1/2]

◆ calc() [2/2]

◆ calcDiff() [1/2]

◆ calcDiff() [2/2]

◆ createData()

◆ quasiStatic()

◆ print()

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