Center of pressure residual function. More...

#include <contact-cop-position.hpp>

Inheritance diagram for ResidualModelContactCoPPositionTpl< _Scalar >:

Public Types
typedef ResidualModelAbstractTpl< Scalar >	Base
typedef CoPSupportTpl< Scalar >	CoPSupport
typedef ResidualDataContactCoPPositionTpl< Scalar >	Data
typedef DataCollectorAbstractTpl< Scalar >	DataCollectorAbstract
typedef MathBaseTpl< Scalar >	MathBase
typedef MathBase::Matrix46s	Matrix46
typedef MathBase::MatrixXs	MatrixXs
typedef ResidualDataAbstractTpl< Scalar >	ResidualDataAbstract
typedef StateMultibodyTpl< Scalar >	StateMultibody
typedef MathBase::VectorXs	VectorXs
Public Types inherited from ResidualModelAbstractTpl< _Scalar >
typedef ActivationDataAbstractTpl< Scalar >	ActivationDataAbstract
typedef CostDataAbstractTpl< Scalar >	CostDataAbstract
typedef DataCollectorAbstractTpl< Scalar >	DataCollectorAbstract
typedef MathBase::DiagonalMatrixXs	DiagonalMatrixXs
typedef MathBaseTpl< Scalar >	MathBase
typedef MathBase::MatrixXs	MatrixXs
typedef ResidualDataAbstractTpl< Scalar >	ResidualDataAbstract
typedef StateAbstractTpl< Scalar >	StateAbstract
typedef MathBase::VectorXs	VectorXs

Public Member Functions
	ResidualModelContactCoPPositionTpl (std::shared_ptr< StateMultibody > state, const pinocchio::FrameIndex id, const CoPSupport &cref)
	Initialize the contact CoP residual model.
	ResidualModelContactCoPPositionTpl (std::shared_ptr< StateMultibody > state, const pinocchio::FrameIndex id, const CoPSupport &cref, const std::size_t nu, const bool fwddyn=true)
	Initialize the contact CoP residual model.
virtual void	calc (const std::shared_ptr< ResidualDataAbstract > &data, const Eigen::Ref< const VectorXs > &x) override
	Compute the residual vector for nodes that depends only on the state.
virtual void	calc (const std::shared_ptr< ResidualDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u) override
	Compute the contact CoP residual.
virtual void	calcDiff (const std::shared_ptr< ResidualDataAbstract > &data, const Eigen::Ref< const VectorXs > &x) override
	Compute the Jacobian of the residual functions with respect to the state only.
virtual void	calcDiff (const std::shared_ptr< ResidualDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u) override
	Compute the Jacobians of the contact CoP residual.
template<typename NewScalar>
ResidualModelContactCoPPositionTpl< NewScalar >	cast () const
	Cast the contact-cop-position residual model to a different scalar type.
virtual std::shared_ptr< ResidualDataAbstract >	createData (DataCollectorAbstract *const data) override
	Create the contact CoP residual data.
	DEPRECATED ("Do not use set_id, instead create a new model", void set_id(pinocchio::FrameIndex id);) void set_reference(const CoPSupport &reference)
	Modify the reference frame id.
pinocchio::FrameIndex	get_id () const
	Return the reference frame id.
const CoPSupport &	get_reference () const
	Return the reference support region of CoP.
bool	is_fwddyn () const
	Indicates if we are using the forward-dynamics (true) or inverse-dynamics (false)
virtual void	print (std::ostream &os) const override
	Print relevant information of the cop-position residual.
void	updateJacobians (const std::shared_ptr< ResidualDataAbstract > &data)
	Update the Jacobians of the contact friction cone residual.
Public Member Functions inherited from ResidualModelAbstractTpl< _Scalar >
	ResidualModelAbstractTpl (std::shared_ptr< StateAbstract > state, const std::size_t nr, const bool q_dependent=true, const bool v_dependent=true, const bool u_dependent=true)
	Initialize the residual model.
	ResidualModelAbstractTpl (std::shared_ptr< StateAbstract > state, const std::size_t nr, const std::size_t nu, const bool q_dependent=true, const bool v_dependent=true, const bool u_dependent=true)
	Initialize the residual model.
virtual void	calcCostDiff (const std::shared_ptr< CostDataAbstract > &cdata, const std::shared_ptr< ResidualDataAbstract > &rdata, const std::shared_ptr< ActivationDataAbstract > &adata, const bool update_u=true)
	Compute the derivative of the cost function.
std::size_t	get_nr () const
	Return the dimension of the residual vector.
std::size_t	get_nu () const
	Return the dimension of the control input.
bool	get_q_dependent () const
	Return true if the residual function depends on q.
const std::shared_ptr< StateAbstract > &	get_state () const
	Return the state.
bool	get_u_dependent () const
	Return true if the residual function depends on u.
bool	get_v_dependent () const
	Return true if the residual function depends on v.

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

Protected Attributes
std::size_t	nu_
	Control dimension.
std::shared_ptr< StateAbstract >	state_
	State description.
Protected Attributes inherited from ResidualModelAbstractTpl< _Scalar >
std::size_t	nr_
	Residual vector dimension.
std::size_t	nu_
	Control dimension.
bool	q_dependent_
std::shared_ptr< StateAbstract >	state_
	State description.
bool	u_dependent_
VectorXs	unone_
	No control vector.
bool	v_dependent_

Detailed Description

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

Center of pressure residual function.

It builds a residual function that bounds the center of pressure (CoP) for one contact surface to lie inside a certain geometric area defined around the reference contact frame. The residual residual vector is described as $\mathbf{r}=\mathbf{A}\boldsymbol{\lambda}\geq\mathbf{0}$ , where

$\mathbf{A}= \begin{bmatrix} 0 & 0 & X/2 & 0 & -1 & 0 \\ 0 & 0 & X/2 & 0 & 1 & 0 \\ 0 & 0 & Y/2 & 1 & 0 & 0 \\ 0 & 0 & Y/2 & -1 & 0 & 0 \end{bmatrix}$

is the inequality matrix and $\boldsymbol{\lambda}$ is the reference spatial contact force in the frame coordinate. The CoP lies inside the convex hull of the foot, see eq.(18-19) of https://hal.archives-ouvertes.fr/hal-02108449/document is we have:

$\begin{align}\begin{split}\tau^x &\leq Yf^z \\-\tau^x &\leq Yf^z \\\tau^y &\leq Yf^z \\-\tau^y &\leq Yf^z \end{split}\end{align}$

with $\boldsymbol{\lambda}= \begin{bmatrix}f^x & f^y & f^z & \tau^x & \tau^y & \tau^z \end{bmatrix}^T$ .

The residual is computed, from the residual vector $\mathbf{r}$ , through an user defined activation model. Additionally, the contact frame id, the desired support region for the CoP and the inequality matrix are handled within CoPSupportTpl. The force vector $\boldsymbol{\lambda}$ and its derivatives are computed by DifferentialActionModelContactFwdDynamicsTpl or ActionModelImpulseFwdDynamicTpl. These values are stored in a shared data (i.e., DataCollectorContactTpl or DataCollectorImpulseTpl). Note that this residual function cannot be used with other action models.

See also: ResidualModelAbstractTpl, calc(), calcDiff(), createData(), DifferentialActionModelContactFwdDynamicsTpl, ActionModelImpulseFwdDynamicTpl, DataCollectorForceTpl

Definition at line 66 of file contact-cop-position.hpp.

Member Typedef Documentation

◆ MathBase

template<typename _Scalar>

typedef MathBaseTpl<Scalar> MathBase

Definition at line 73 of file contact-cop-position.hpp.

◆ Base

template<typename _Scalar>

typedef ResidualModelAbstractTpl<Scalar> Base

Definition at line 74 of file contact-cop-position.hpp.

◆ Data

template<typename _Scalar>

typedef ResidualDataContactCoPPositionTpl<Scalar> Data

Definition at line 75 of file contact-cop-position.hpp.

◆ StateMultibody

template<typename _Scalar>

typedef StateMultibodyTpl<Scalar> StateMultibody

Definition at line 76 of file contact-cop-position.hpp.

◆ ResidualDataAbstract

template<typename _Scalar>

typedef ResidualDataAbstractTpl<Scalar> ResidualDataAbstract

Definition at line 77 of file contact-cop-position.hpp.

◆ DataCollectorAbstract

template<typename _Scalar>

typedef DataCollectorAbstractTpl<Scalar> DataCollectorAbstract

Definition at line 78 of file contact-cop-position.hpp.

◆ CoPSupport

template<typename _Scalar>

typedef CoPSupportTpl<Scalar> CoPSupport

Definition at line 79 of file contact-cop-position.hpp.

◆ VectorXs

template<typename _Scalar>

typedef MathBase::VectorXs VectorXs

Definition at line 80 of file contact-cop-position.hpp.

◆ MatrixXs

template<typename _Scalar>

typedef MathBase::MatrixXs MatrixXs

Definition at line 81 of file contact-cop-position.hpp.

◆ Matrix46

template<typename _Scalar>

typedef MathBase::Matrix46s Matrix46

Definition at line 82 of file contact-cop-position.hpp.

Constructor & Destructor Documentation

◆ ResidualModelContactCoPPositionTpl() [1/2]

template<typename _Scalar>

ResidualModelContactCoPPositionTpl	(	std::shared_ptr< StateMultibody >	state,
		const pinocchio::FrameIndex	id,
		const CoPSupport &	cref,
		const std::size_t	nu,
		const bool	fwddyn = true )

Initialize the contact CoP residual model.

Note that for the inverse-dynamic cases, the control vector contains the generalized accelerations, torques, and all the contact forces.

Parameters

[in]	state	State of the multibody system
[in]	id	Reference frame id
[in]	cref	Reference support region of the CoP
[in]	nu	Dimension of control vector
[in]	fwddyn	Indicates that we have a forward dynamics problem (true) or inverse dynamics (false)

◆ ResidualModelContactCoPPositionTpl() [2/2]

template<typename _Scalar>

ResidualModelContactCoPPositionTpl	(	std::shared_ptr< StateMultibody >	state,
		const pinocchio::FrameIndex	id,
		const CoPSupport &	cref )

Initialize the contact CoP residual model.

The default nu value is obtained from StateAbstractTpl::get_nv(). Note that this constructor can be used for forward-dynamics cases only.

Parameters

[in]	state	State of the multibody system
[in]	id	Reference frame id
[in]	cref	Reference support region of the CoP

Member Function Documentation

◆ calc() [1/2]

template<typename _Scalar>

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

overridevirtual

Compute the contact CoP residual.

The CoP residual is computed based on the $\mathbf{A}$ matrix, the force vector is computed by DifferentialActionModelContactFwdDynamicsTpl or ActionModelImpulseFwdDynamicTpl which is stored in DataCollectorContactTpl or DataCollectorImpulseTpl.

Parameters

[in]	data	Contact CoP data
[in]	x	State point $\mathbf{x}\in\mathbb{R}^{ndx}$
[in]	u	Control input $\mathbf{u}\in\mathbb{R}^{nu}$

Reimplemented from ResidualModelAbstractTpl< _Scalar >.

◆ calc() [2/2]

template<typename _Scalar>

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

overridevirtual

Compute the residual vector for nodes that depends only on the state.

It updates the residual vector based on the state only (i.e., it ignores the contact forces). This function is used in the terminal nodes of an optimal control problem.

Parameters

[in]	data	Residual data
[in]	x	State point $\mathbf{x}\in\mathbb{R}^{ndx}$

Reimplemented from ResidualModelAbstractTpl< _Scalar >.

◆ calcDiff() [1/2]

template<typename _Scalar>

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

overridevirtual

Compute the Jacobians of the contact CoP residual.

The CoP residual is computed based on the $\mathbf{A}$ matrix, the force vector is computed by DifferentialActionModelContactFwdDynamicsTpl or ActionModelImpulseFwdDynamicTpl which is stored in DataCollectorContactTpl or DataCollectorImpulseTpl.

Parameters

[in]	data	Contact CoP data
[in]	x	State point $\mathbf{x}\in\mathbb{R}^{ndx}$
[in]	u	Control input $\mathbf{u}\in\mathbb{R}^{nu}$

Reimplemented from ResidualModelAbstractTpl< _Scalar >.

◆ calcDiff() [2/2]

template<typename _Scalar>

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

overridevirtual

Compute the Jacobian of the residual functions with respect to the state only.

It updates the Jacobian of the residual function based on the state only (i.e., it ignores the contact forces). This function is used in the terminal nodes of an optimal control problem.

Parameters

[in]	data	Residual data
[in]	x	State point $\mathbf{x}\in\mathbb{R}^{ndx}$

Reimplemented from ResidualModelAbstractTpl< _Scalar >.

◆ createData()

template<typename _Scalar>

virtual std::shared_ptr< ResidualDataAbstract > createData ( DataCollectorAbstract *const data )

overridevirtual

Create the contact CoP residual data.

Each residual model has its own data that needs to be allocated. This function returns the allocated data for a predefined residual.

Parameters

[in] data Shared data (it should be of type DataCollectorContactTpl)

Returns: the residual data.

Reimplemented from ResidualModelAbstractTpl< _Scalar >.

◆ updateJacobians()

template<typename _Scalar>

void updateJacobians ( const std::shared_ptr< ResidualDataAbstract > & data )

Update the Jacobians of the contact friction cone residual.

Parameters

[in] data Contact friction cone residual data

◆ cast()

template<typename _Scalar>

template<typename NewScalar>

ResidualModelContactCoPPositionTpl< NewScalar > cast ( ) const

Cast the contact-cop-position residual model to a different scalar type.

It is useful for operations requiring different precision or scalar types.

Template Parameters

NewScalar The new scalar type to cast to.

Returns: ResidualModelContactCoPPositionTpl<NewScalar> A residual model with the new scalar type.

◆ DEPRECATED()

template<typename _Scalar>

DEPRECATED	(	"Do not use	set_id,
		instead create a new model"	,
		void set_id(pinocchio::FrameIndex id);	) const &

Modify the reference frame id.

Modify the reference support region of CoP

◆ print()

template<typename _Scalar>

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

overridevirtual

Print relevant information of the cop-position residual.

Parameters

[out] os Output stream object

Reimplemented from ResidualModelAbstractTpl< _Scalar >.

Member Data Documentation

◆ Scalar

template<typename _Scalar>

EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar Scalar

Definition at line 72 of file contact-cop-position.hpp.

◆ nu_

template<typename _Scalar>

std::size_t nu_

protected

Control dimension.

Definition at line 232 of file residual-base.hpp.

◆ state_

template<typename _Scalar>

std::shared_ptr<StateAbstract> state_

protected

State description.

Definition at line 230 of file residual-base.hpp.

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

/build/source/include/crocoddyl/multibody/fwd.hpp
/build/source/include/crocoddyl/multibody/residuals/contact-cop-position.hpp

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ MathBase

◆ Base

◆ Data

◆ StateMultibody

◆ ResidualDataAbstract

◆ DataCollectorAbstract

◆ CoPSupport

◆ VectorXs

◆ MatrixXs

◆ Matrix46

Constructor & Destructor Documentation

◆ ResidualModelContactCoPPositionTpl() [1/2]

◆ ResidualModelContactCoPPositionTpl() [2/2]

Member Function Documentation

◆ calc() [1/2]

◆ calc() [2/2]

◆ calcDiff() [1/2]

◆ calcDiff() [2/2]

◆ createData()

◆ updateJacobians()

◆ cast()

◆ DEPRECATED()

◆ print()

Member Data Documentation

◆ Scalar

◆ nu_

◆ state_