CostModelContactForceTpl< _Scalar > Class Template Reference

Define a contact force cost function. More...

#include <crocoddyl/multibody/costs/contact-force.hpp>

Inheritance diagram for CostModelContactForceTpl< _Scalar >:

Collaboration diagram for CostModelContactForceTpl< _Scalar >:

Public Types
typedef ActivationModelAbstractTpl< Scalar >	ActivationModelAbstract
typedef CostModelResidualTpl< Scalar >	Base
typedef FrameForceTpl< Scalar >	FrameForce
typedef MathBaseTpl< Scalar >	MathBase
typedef MathBase::MatrixXs	MatrixXs
typedef ResidualModelContactForceTpl< Scalar >	ResidualModelContactForce
typedef StateMultibodyTpl< Scalar >	StateMultibody
typedef MathBase::VectorXs	VectorXs
Public Types inherited from CostModelResidualTpl< _Scalar >
typedef ActivationModelAbstractTpl< Scalar >	ActivationModelAbstract
typedef CostModelAbstractTpl< Scalar >	Base
typedef CostDataAbstractTpl< Scalar >	CostDataAbstract
typedef CostDataResidualTpl< Scalar >	Data
typedef DataCollectorAbstractTpl< Scalar >	DataCollectorAbstract
typedef MathBaseTpl< Scalar >	MathBase
typedef MathBase::MatrixXs	MatrixXs
typedef ResidualModelAbstractTpl< Scalar >	ResidualModelAbstract
typedef MathBase::VectorXs	VectorXs
Public Types inherited from CostModelAbstractTpl< _Scalar >
typedef ActivationModelAbstractTpl< Scalar >	ActivationModelAbstract
typedef ActivationModelQuadTpl< Scalar >	ActivationModelQuad
typedef CostDataAbstractTpl< Scalar >	CostDataAbstract
typedef DataCollectorAbstractTpl< Scalar >	DataCollectorAbstract
typedef MathBaseTpl< Scalar >	MathBase
typedef MathBase::MatrixXs	MatrixXs
typedef ResidualModelAbstractTpl< Scalar >	ResidualModelAbstract
typedef StateAbstractTpl< Scalar >	StateAbstract
typedef MathBase::VectorXs	VectorXs

Public Member Functions
	CostModelContactForceTpl (boost::shared_ptr< StateMultibody > state, boost::shared_ptr< ActivationModelAbstract > activation, const FrameForce &fref)
	Initialize the contact force cost model. More...
	CostModelContactForceTpl (boost::shared_ptr< StateMultibody > state, boost::shared_ptr< ActivationModelAbstract > activation, const FrameForce &fref, const std::size_t nu)
	Initialize the contact force cost model. More...
	CostModelContactForceTpl (boost::shared_ptr< StateMultibody > state, const FrameForce &fref)
	Initialize the contact force cost model. More...
	CostModelContactForceTpl (boost::shared_ptr< StateMultibody > state, const FrameForce &fref, const std::size_t nr)
	Initialize the contact force cost model. More...
	CostModelContactForceTpl (boost::shared_ptr< StateMultibody > state, const FrameForce &fref, const std::size_t nr, const std::size_t nu)
	Initialize the contact force cost model. More...
Public Member Functions inherited from CostModelResidualTpl< _Scalar >
	CostModelResidualTpl (boost::shared_ptr< typename Base::StateAbstract > state, boost::shared_ptr< ActivationModelAbstract > activation, boost::shared_ptr< ResidualModelAbstract > residual)
	Initialize the residual cost model. More...
	CostModelResidualTpl (boost::shared_ptr< typename Base::StateAbstract > state, boost::shared_ptr< ResidualModelAbstract > residual)
	Initialize the residual cost model. More...
virtual void	calc (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x)
	Compute the residual cost based on state only. More...
virtual void	calc (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the residual cost. More...
virtual void	calcDiff (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x)
	Compute the derivatives of the residual cost with respect to the state only. More...
virtual void	calcDiff (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the derivatives of the residual cost. More...
virtual boost::shared_ptr< CostDataAbstract >	createData (DataCollectorAbstract *const data)
	Create the residual cost data.
virtual void	print (std::ostream &os) const
	Print relevant information of the cost-residual model. More...
Public Member Functions inherited from CostModelAbstractTpl< _Scalar >
	CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, boost::shared_ptr< ActivationModelAbstract > activation)
	Initialize the cost model. More...
	CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, boost::shared_ptr< ActivationModelAbstract > activation, boost::shared_ptr< ResidualModelAbstract > residual)
	Initialize the cost model. More...
	CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, boost::shared_ptr< ActivationModelAbstract > activation, const std::size_t nu)
	Initialize the cost model. More...
	CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, boost::shared_ptr< ResidualModelAbstract > residual)
	Initialize the cost model. More...
	CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, const std::size_t nr)
	Initialize the cost model. More...
	CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, const std::size_t nr, const std::size_t nu)
	Initialize the cost model. More...
const boost::shared_ptr< ActivationModelAbstract > &	get_activation () const
	Return the activation model.
std::size_t	get_nu () const
	Return the dimension of the control input.
template<class ReferenceType >
ReferenceType	get_reference ()
	Return the cost reference.
const boost::shared_ptr< ResidualModelAbstract > &	get_residual () const
	Return the residual model.
const boost::shared_ptr< StateAbstract > &	get_state () const
	Return the state.
template<class ReferenceType >
void	set_reference (ReferenceType ref)
	Modify the cost reference.

Public Attributes
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar
Public Attributes inherited from CostModelResidualTpl< _Scalar >
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar
Public Attributes inherited from CostModelAbstractTpl< _Scalar >
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar

Protected Member Functions
virtual void	get_referenceImpl (const std::type_info &ti, void *pv)
	Modify the reference spatial contact force \(\boldsymbol{\lambda}^*\).
virtual void	set_referenceImpl (const std::type_info &ti, const void *pv)
	Return the reference spatial contact force \(\boldsymbol{\lambda}^*\).

Protected Attributes
boost::shared_ptr< ActivationModelAbstract >	activation_
	Activation model.
FrameForce	fref_
	Reference spatial contact force \(\boldsymbol{\lambda}^*\).
std::size_t	nu_
	Control dimension.
boost::shared_ptr< ResidualModelAbstract >	residual_
	Residual model.
boost::shared_ptr< StateAbstract >	state_
	State description.
VectorXs	unone_
	No control vector.
Protected Attributes inherited from CostModelResidualTpl< _Scalar >
boost::shared_ptr< ActivationModelAbstract >	activation_
	Activation model.
std::size_t	nu_
	Control dimension.
boost::shared_ptr< ResidualModelAbstract >	residual_
	Residual model.
boost::shared_ptr< StateAbstract >	state_
	State description.
VectorXs	unone_
	No control vector.
Protected Attributes inherited from CostModelAbstractTpl< _Scalar >
boost::shared_ptr< ActivationModelAbstract >	activation_
	Activation model.
std::size_t	nu_
	Control dimension.
boost::shared_ptr< ResidualModelAbstract >	residual_
	Residual model.
boost::shared_ptr< StateAbstract >	state_
	State description.
VectorXs	unone_
	No control vector.

Detailed Description

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

Define a contact force cost function.

This cost function defines a residual vector \(\mathbf{r}=\boldsymbol{\lambda}-\boldsymbol{\lambda}^*\), where \(\boldsymbol{\lambda}, \boldsymbol{\lambda}^*\) are the current and reference spatial forces, respectively. The current spatial forces \(\boldsymbol{\lambda}\in\mathbb{R}^{nc}\)is computed by DifferentialActionModelContactFwdDynamicsTpl, with nc as the dimension of the contact.

Both cost and residual derivatives are computed analytically, where th force vector \(\boldsymbol{\lambda}\) and its derivatives \(\left(\frac{\partial\boldsymbol{\lambda}}{\partial\mathbf{x}}, \frac{\partial\boldsymbol{\lambda}}{\partial\mathbf{u}}\right)\) are computed by DifferentialActionModelContactFwdDynamicsTpl. These values are stored in a shared data (i.e. DataCollectorContactTpl). Note that this cost function cannot be used with other action models. For the computation of the cost Hessian, we use the Gauss-Newton approximation, e.g. \(\mathbf{l_{xu}} = \mathbf{l_{x}}^T \mathbf{l_{u}} \).

See also

DifferentialActionModelContactFwdDynamicsTpl, DataCollectorContactTpl, ActivationModelAbstractTpl

Definition at line 43 of file contact-force.hpp.

Constructor & Destructor Documentation

CostModelContactForceTpl() [1/5]

CostModelContactForceTpl	(	boost::shared_ptr< StateMultibody >	state,
		boost::shared_ptr< ActivationModelAbstract >	activation,
		const FrameForce &	fref,
		const std::size_t	nu
	)

Initialize the contact force cost model.

Note that the nr, defined in the activation model, has to be lower / equals than 6.

Parameters

[in]	state	Multibody state
[in]	activation	Activation model
[in]	fref	Reference spatial contact force \(\boldsymbol{\lambda}^*\)
[in]	nu	Dimension of control vector

CostModelContactForceTpl() [2/5]

CostModelContactForceTpl	(	boost::shared_ptr< StateMultibody >	state,
		boost::shared_ptr< ActivationModelAbstract >	activation,
		const FrameForce &	fref
	)

Initialize the contact force cost model.

The default nu is obtained from StateAbstractTpl::get_nv(). Note that the nr, defined in the activation model, has to be lower / equals than 6.

Parameters

[in]	state	Multibody state
[in]	activation	Activation model
[in]	fref	Reference spatial contact force \(\boldsymbol{\lambda}^*\)

CostModelContactForceTpl() [3/5]

CostModelContactForceTpl	(	boost::shared_ptr< StateMultibody >	state,
		const FrameForce &	fref,
		const std::size_t	nr,
		const std::size_t	nu
	)

Initialize the contact force cost model.

We use ActivationModelQuadTpl as a default activation model (i.e. \(a=\frac{1}{2}\|\mathbf{r}\|^2\)). Note that the nr, defined in the activation model, has to be lower / equals than 6.

Parameters

[in]	state	Multibody state
[in]	fref	Reference spatial contact force \(\boldsymbol{\lambda}^*\)
[in]	nr	Dimension of residual vector
[in]	nu	Dimension of control vector

CostModelContactForceTpl() [4/5]

CostModelContactForceTpl	(	boost::shared_ptr< StateMultibody >	state,
		const FrameForce &	fref,
		const std::size_t	nr
	)

Initialize the contact force cost model.

We use ActivationModelQuadTpl as a default activation model (i.e. \(a=\frac{1}{2}\|\mathbf{r}\|^2\)), and nu is obtained from StateAbstractTpl::get_nv(). Note that the nr, defined in the activation model, has to be lower / equals than 6.

Parameters

[in]	state	Multibody state
[in]	fref	Reference spatial contact force \(\boldsymbol{\lambda}^*\)
[in]	nr	Dimension of residual vector

CostModelContactForceTpl() [5/5]

CostModelContactForceTpl	(	boost::shared_ptr< StateMultibody >	state,
		const FrameForce &	fref
	)

Initialize the contact force cost model.

We use ActivationModelQuadTpl as a default activation model (i.e. \(a=\frac{1}{2}\|\mathbf{r}\|^2\)), and nr and nu are equals to 6 and StateAbstractTpl::get_nv(), respectively.

Parameters

[in]	state	Multibody state
[in]	fref	Reference spatial contact force \(\boldsymbol{\lambda}^*\)

---

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

• include/crocoddyl/multibody/costs/contact-force.hpp