Define a center of pressure cost function. More...
#include <crocoddyl/multibody/costs/contact-cop-position.hpp>
Public Types | |
typedef ActivationBoundsTpl< Scalar > | ActivationBounds |
typedef ActivationModelAbstractTpl< Scalar > | ActivationModelAbstract |
typedef ActivationModelQuadraticBarrierTpl< Scalar > | ActivationModelQuadraticBarrier |
typedef CostModelAbstractTpl< Scalar > | Base |
typedef CostDataAbstractTpl< Scalar > | CostDataAbstract |
typedef CostDataContactCoPPositionTpl< Scalar > | Data |
typedef DataCollectorAbstractTpl< Scalar > | DataCollectorAbstract |
typedef FrameCoPSupportTpl< Scalar > | FrameCoPSupport |
typedef MathBaseTpl< Scalar > | MathBase |
typedef Eigen::Matrix< Scalar, 4, 6 > | Matrix46 |
typedef MathBase::MatrixXs | MatrixXs |
typedef StateMultibodyTpl< Scalar > | StateMultibody |
typedef MathBase::Vector2s | Vector2s |
typedef MathBase::Vector3s | Vector3s |
typedef MathBase::VectorXs | VectorXs |
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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 StateAbstractTpl< Scalar > | StateAbstract |
typedef MathBase::VectorXs | VectorXs |
Public Member Functions | |
CostModelContactCoPPositionTpl (boost::shared_ptr< StateMultibody > state, boost::shared_ptr< ActivationModelAbstract > activation, const FrameCoPSupport &cop_support, const std::size_t &nu) | |
Initialize the contact CoP cost model. More... | |
CostModelContactCoPPositionTpl (boost::shared_ptr< StateMultibody > state, boost::shared_ptr< ActivationModelAbstract > activation, const FrameCoPSupport &cop_support) | |
Initialize the contact CoP cost model. More... | |
CostModelContactCoPPositionTpl (boost::shared_ptr< StateMultibody > state, const FrameCoPSupport &cop_support, const std::size_t &nu) | |
Initialize the contact CoP cost model. More... | |
CostModelContactCoPPositionTpl (boost::shared_ptr< StateMultibody > state, const FrameCoPSupport &cop_support) | |
Initialize the contact CoP cost model. More... | |
virtual void | calc (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u) |
Compute the contact CoP cost. 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 contact CoP cost. More... | |
virtual boost::shared_ptr< CostDataAbstract > | createData (DataCollectorAbstract *const data) |
Create the contact CoP cost data. More... | |
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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< ActivationModelAbstract > activation) | |
CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, const std::size_t &nr, const std::size_t &nu) | |
CostModelAbstractTpl (boost::shared_ptr< StateAbstract > state, const std::size_t &nr) | |
virtual void | calc (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)=0 |
Compute the cost value and its residual vector. More... | |
void | calc (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x) |
virtual void | calcDiff (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)=0 |
Compute the Jacobian and Hessian of cost and its residual vector. More... | |
void | calcDiff (const boost::shared_ptr< CostDataAbstract > &data, const Eigen::Ref< const VectorXs > &x) |
const boost::shared_ptr< ActivationModelAbstract > & | get_activation () const |
Return the activation model. | |
const std::size_t & | get_nu () const |
Return the dimension of the control input. | |
template<class ReferenceType > | |
ReferenceType | get_reference () const |
Return the cost reference. | |
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 |
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EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar | Scalar |
Protected Member Functions | |
virtual void | get_referenceImpl (const std::type_info &ti, void *pv) const |
Modify the frame CoP support. | |
virtual void | set_referenceImpl (const std::type_info &ti, const void *pv) |
Return the frame CoP support. | |
Additional Inherited Members | |
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boost::shared_ptr< ActivationModelAbstract > | activation_ |
Activation model. | |
std::size_t | nu_ |
Control dimension. | |
boost::shared_ptr< StateAbstract > | state_ |
State description. | |
VectorXs | unone_ |
No control vector. | |
Define a center of pressure cost function.
It builds a cost 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 cost 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 cost 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 FrameCoPSupportTpl
. The force vector \(\boldsymbol{\lambda}\) and its derivatives 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.
Definition at line 57 of file contact-cop-position.hpp.
CostModelContactCoPPositionTpl | ( | boost::shared_ptr< StateMultibody > | state, |
boost::shared_ptr< ActivationModelAbstract > | activation, | ||
const FrameCoPSupport & | cop_support, | ||
const std::size_t & | nu | ||
) |
Initialize the contact CoP cost model.
[in] | state | State of the multibody system |
[in] | activation | Activation model |
[in] | cop_support | Id of contact frame and support region of the CoP |
[in] | nu | Dimension of control vector |
CostModelContactCoPPositionTpl | ( | boost::shared_ptr< StateMultibody > | state, |
boost::shared_ptr< ActivationModelAbstract > | activation, | ||
const FrameCoPSupport & | cop_support | ||
) |
Initialize the contact CoP cost model.
The default nu
value is obtained from StateAbstractTpl::get_nv()
.
[in] | state | State of the multibody system |
[in] | activation | Activation model |
[in] | cop_support | Id of contact frame and support region of the CoP |
CostModelContactCoPPositionTpl | ( | boost::shared_ptr< StateMultibody > | state, |
const FrameCoPSupport & | cop_support, | ||
const std::size_t & | nu | ||
) |
Initialize the contact CoP cost model.
We use as default activation model a quadratic barrier ActivationModelQuadraticBarrierTpl
, with 0 and inf as lower and upper bounds, respectively.
[in] | state | State of the multibody system |
[in] | cop_support | Id of contact frame and support region of the cop |
[in] | nu | Dimension of control vector |
CostModelContactCoPPositionTpl | ( | boost::shared_ptr< StateMultibody > | state, |
const FrameCoPSupport & | cop_support | ||
) |
Initialize the contact CoP cost model.
We use as default activation model a quadratic barrier ActivationModelQuadraticBarrierTpl
, with 0 and inf as lower and upper bounds, respectively. Additionally, the default nu
value is obtained from StateAbstractTpl::get_nv()
[in] | state | State of the multibody system |
[in] | cop_support | Id of contact frame and support region of the cop |
|
virtual |
Compute the contact CoP cost.
The CoP residual is computed based on the \(\mathbf{A}\) matrix, the force vector is computed by DifferentialActionModelContactFwdDynamicsTpl
which is stored in `DataCollectorContactTpl.
[in] | data | Contact CoP data |
[in] | x | State point \(\mathbf{x}\in\mathbb{R}^{ndx}\) |
[in] | u | Control input \(\mathbf{u}\in\mathbb{R}^{nu}\) |
|
virtual |
Compute the derivatives of the contact CoP cost.
The CoP derivatives are based on the force derivatives computed by DifferentialActionModelContactFwdDynamicsTpl
which are stored in DataCollectorContactTpl
.
[in] | data | Contact CoP data |
[in] | x | State point \(\mathbf{x}\in\mathbb{R}^{ndx}\) |
[in] | u | Control input \(\mathbf{u}\in\mathbb{R}^{nu}\) |
|
virtual |
Create the contact CoP cost data.
Each cost model has its own data that needs to be allocated. This function returns the allocated data for a predefined cost.
[in] | data | Shared data (it should be of type DataCollectorContactTpl ) |
Reimplemented from CostModelAbstractTpl< _Scalar >.