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ActionModelAbstractTpl< _Scalar > Class Template Referenceabstract

Abstract class for action model. More...

#include <action-base.hpp>

Inheritance diagram for ActionModelAbstractTpl< _Scalar >:
ActionModelBase ActionModelImpulseFwdDynamicsTpl< _Scalar > ActionModelLQRTpl< _Scalar > ActionModelNumDiffTpl< _Scalar > ActionModelUnicycleTpl< _Scalar > IntegratedActionModelAbstractTpl< _Scalar > IntegratedActionModelEulerTpl< _Scalar > IntegratedActionModelRKTpl< _Scalar >

Public Types

typedef ActionDataAbstractTpl< Scalar > ActionDataAbstract
 
typedef MathBaseTpl< Scalar > MathBase
 
typedef ScalarSelector< Scalar >::type ScalarType
 
typedef StateAbstractTpl< Scalar > StateAbstract
 
typedef MathBase::VectorXs VectorXs
 

Public Member Functions

 ActionModelAbstractTpl (const ActionModelAbstractTpl< Scalar > &other)
 Copy constructor.
 
 ActionModelAbstractTpl (std::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, const std::size_t ng_T=0, const std::size_t nh_T=0)
 Initialize the action model.
 
virtual void calc (const std::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x)
 Compute the total cost value for nodes that depends only on the state.
 
virtual void calc (const std::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)=0
 Compute the next state and cost value.
 
virtual void calcDiff (const std::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x)
 Compute the derivatives of the cost functions with respect to the state only.
 
virtual void calcDiff (const std::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)=0
 Compute the derivatives of the dynamics and cost functions.
 
virtual bool checkData (const std::shared_ptr< ActionDataAbstract > &data)
 Checks that a specific data belongs to this model.
 
virtual std::shared_ptr< ActionDataAbstractcreateData ()
 Create the action data.
 
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.
 
bool get_has_control_limits () const
 Indicates if there are defined control limits.
 
virtual std::size_t get_ng () const
 Return the number of inequality constraints.
 
virtual std::size_t get_ng_T () const
 Return the number of inequality terminal constraints.
 
virtual std::size_t get_nh () const
 Return the number of equality constraints.
 
virtual std::size_t get_nh_T () const
 Return the number of equality terminal constraints.
 
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 std::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.
 
virtual void print (std::ostream &os) const
 Print relevant information of the action model.
 
virtual void quasiStatic (const std::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.
 
VectorXs quasiStatic_x (const std::shared_ptr< ActionDataAbstract > &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
 

Protected Member Functions

void update_has_control_limits ()
 Update the status of the control limits (i.e. if there are defined limits)
 

Protected Attributes

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 ng_T_
 Number of inequality terminal constraints.
 
std::size_t nh_
 Number of equality constraints.
 
std::size_t nh_T_
 Number of equality terminal constraints.
 
std::size_t nr_
 Dimension of the cost residual.
 
std::size_t nu_
 Control dimension.
 
std::shared_ptr< StateAbstractstate_
 Model of the state.
 
VectorXs u_lb_
 Lower control limits.
 
VectorXs u_ub_
 Upper control limits.
 
VectorXs unone_
 Neutral state.
 

Friends

template<class Scalar >
class ConstraintModelManagerTpl
 
template<class Scalar >
std::ostream & operator<< (std::ostream &os, const ActionModelAbstractTpl< Scalar > &model)
 Print information on the action model.
 

Detailed Description

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

Abstract class for action model.

An action model combines dynamics, cost functions and constraints. Each node, in our optimal control problem, is described through an action model. Every time that we want describe a problem, we need to provide ways of computing the dynamics, cost functions, constraints and their derivatives. All these is described inside the action model.

Concretely speaking, the action model describes a time-discrete action model with a first-order ODE along a cost function, i.e.

  • the state \(\mathbf{z}\in\mathcal{Z}\) lies in a manifold described with a nx-tuple,
  • the state rate \(\mathbf{\dot{x}}\in T_{\mathbf{q}}\mathcal{Q}\) is the tangent vector to the state manifold with ndx dimension,
  • the control input \(\mathbf{u}\in\mathbb{R}^{nu}\) is an Euclidean vector
  • \(\mathbf{r}(\cdot)\) and \(a(\cdot)\) are the residual and activation functions (see ResidualModelAbstractTpl and ActivationModelAbstractTpl, respetively),
  • \(\mathbf{g}(\cdot)\in\mathbb{R}^{ng}\) and \(\mathbf{h}(\cdot)\in\mathbb{R}^{nh}\) are the inequality and equality vector functions, respectively.

The computation of these equations are carried out out inside calc() function. In short, this function computes the system acceleration, cost and constraints values (also called constraints violations). This procedure is equivalent to running a forward pass of the action model.

However, during numerical optimization, we also need to run backward passes of the action model. These calculations are performed by calcDiff(). In short, this method builds a linear-quadratic approximation of the action model, i.e.:

\[ \begin{aligned} &\delta\mathbf{x}_{k+1} = \mathbf{f_x}\delta\mathbf{x}_k+\mathbf{f_u}\delta\mathbf{u}_k, &\textrm{(dynamics)}\\ &\ell(\delta\mathbf{x}_k,\delta\mathbf{u}_k) = \begin{bmatrix}1 \\ \delta\mathbf{x}_k \\ \delta\mathbf{u}_k\end{bmatrix}^T \begin{bmatrix}0 & \mathbf{\ell_x}^T & \mathbf{\ell_u}^T \\ \mathbf{\ell_x} & \mathbf{\ell_{xx}} & \mathbf{\ell_{ux}}^T \\ \mathbf{\ell_u} & \mathbf{\ell_{ux}} & \mathbf{\ell_{uu}}\end{bmatrix} \begin{bmatrix}1 \\ \delta\mathbf{x}_k \\ \delta\mathbf{u}_k\end{bmatrix}, &\textrm{(cost)}\\ &\mathbf{g}(\delta\mathbf{x}_k,\delta\mathbf{u}_k)<\mathbf{0}, &\textrm{(inequality constraint)}\\ &\mathbf{h}(\delta\mathbf{x}_k,\delta\mathbf{u}_k)=\mathbf{0}, &\textrm{(equality constraint)} \end{aligned} \]

where

  • \(\mathbf{f_x}\in\mathbb{R}^{ndx\times ndx}\) and \(\mathbf{f_u}\in\mathbb{R}^{ndx\times nu}\) are the Jacobians of the dynamics,
  • \(\mathbf{\ell_x}\in\mathbb{R}^{ndx}\) and \(\mathbf{\ell_u}\in\mathbb{R}^{nu}\) are the Jacobians of the cost function,
  • \(\mathbf{\ell_{xx}}\in\mathbb{R}^{ndx\times ndx}\), \(\mathbf{\ell_{xu}}\in\mathbb{R}^{ndx\times nu}\) and \(\mathbf{\ell_{uu}}\in\mathbb{R}^{nu\times nu}\) are the Hessians of the cost function,
  • \(\mathbf{g_x}\in\mathbb{R}^{ng\times ndx}\) and \(\mathbf{g_u}\in\mathbb{R}^{ng\times nu}\) are the Jacobians of the inequality constraints, and
  • \(\mathbf{h_x}\in\mathbb{R}^{nh\times ndx}\) and \(\mathbf{h_u}\in\mathbb{R}^{nh\times nu}\) are the Jacobians of the equality constraints.

Additionally, it is important to note that calcDiff() computes the derivatives using the latest stored values by calc(). Thus, we need to first run calc().

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

Definition at line 97 of file action-base.hpp.

Member Typedef Documentation

◆ ScalarType

template<typename _Scalar >
typedef ScalarSelector<Scalar>::type ScalarType

Definition at line 102 of file action-base.hpp.

◆ MathBase

template<typename _Scalar >
typedef MathBaseTpl<Scalar> MathBase

Definition at line 103 of file action-base.hpp.

◆ ActionDataAbstract

template<typename _Scalar >
typedef ActionDataAbstractTpl<Scalar> ActionDataAbstract

Definition at line 104 of file action-base.hpp.

◆ StateAbstract

template<typename _Scalar >
typedef StateAbstractTpl<Scalar> StateAbstract

Definition at line 105 of file action-base.hpp.

◆ VectorXs

template<typename _Scalar >
typedef MathBase::VectorXs VectorXs

Definition at line 106 of file action-base.hpp.

Constructor & Destructor Documentation

◆ ActionModelAbstractTpl() [1/3]

template<typename _Scalar >
ActionModelAbstractTpl ( std::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,
const std::size_t  ng_T = 0,
const std::size_t  nh_T = 0 
)

Initialize the action model.

Parameters
[in]stateState description
[in]nuDimension of control vector
[in]nrDimension of cost-residual vector
[in]ngNumber of inequality constraints (default 0)
[in]nhNumber of equality constraints (default 0)
[in]ng_TNumber of inequality terminal constraints (default 0)
[in]nh_TNumber of equality terminal constraints (default 0)

◆ ActionModelAbstractTpl() [2/3]

template<typename _Scalar >
ActionModelAbstractTpl ( const ActionModelAbstractTpl< Scalar > &  other)

Copy constructor.

Parameters
otherAction model to be copied

◆ ActionModelAbstractTpl() [3/3]

template<typename _Scalar >
ActionModelAbstractTpl ( )
inlineprotected

Definition at line 342 of file action-base.hpp.

Member Function Documentation

◆ calc() [1/2]

template<typename _Scalar >
virtual void calc ( const std::shared_ptr< ActionDataAbstract > &  data,
const Eigen::Ref< const VectorXs > &  x,
const Eigen::Ref< const VectorXs > &  u 
)
pure virtual

Compute the next state and cost value.

Parameters
[in]dataAction data
[in]xState point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]uControl input \(\mathbf{u}\in\mathbb{R}^{nu}\)

Implemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ calc() [2/2]

template<typename _Scalar >
virtual void calc ( const std::shared_ptr< ActionDataAbstract > &  data,
const Eigen::Ref< const VectorXs > &  x 
)
virtual

Compute the total cost value for nodes that depends only on the state.

It updates the total cost and the next state is not computed as it is not expected to change. This function is used in the terminal nodes of an optimal control problem.

Parameters
[in]dataAction data
[in]xState point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ calcDiff() [1/2]

template<typename _Scalar >
virtual void calcDiff ( const std::shared_ptr< ActionDataAbstract > &  data,
const Eigen::Ref< const VectorXs > &  x,
const Eigen::Ref< const VectorXs > &  u 
)
pure virtual

Compute the derivatives of the dynamics and cost functions.

It computes the partial derivatives of the dynamical system and the cost function. It assumes that calc() has been run first. This function builds a linear-quadratic approximation of the action model (i.e. dynamical system and cost function).

Parameters
[in]dataAction data
[in]xState point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]uControl input \(\mathbf{u}\in\mathbb{R}^{nu}\)

Implemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ calcDiff() [2/2]

template<typename _Scalar >
virtual void calcDiff ( const std::shared_ptr< ActionDataAbstract > &  data,
const Eigen::Ref< const VectorXs > &  x 
)
virtual

Compute the derivatives of the cost functions with respect to the state only.

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]dataAction data
[in]xState point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ createData()

◆ checkData()

template<typename _Scalar >
virtual bool checkData ( const std::shared_ptr< ActionDataAbstract > &  data)
virtual

◆ quasiStatic()

template<typename _Scalar >
virtual void quasiStatic ( const std::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]dataAction data
[out]uQuasic static commands
[in]xState point (velocity has to be zero)
[in]maxiterMaximum allowed number of iterations
[in]tolTolerance

Reimplemented in IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ quasiStatic_x()

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

Parameters
[in]dataAction data
[in]xState point (velocity has to be zero)
[in]maxiterMaximum allowed number of iterations
[in]tolTolerance
Returns
Quasic static commands

◆ get_ng()

template<typename _Scalar >
virtual std::size_t get_ng ( ) const
virtual

Return the number of inequality constraints.

Reimplemented in IntegratedActionModelAbstractTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ get_nh()

template<typename _Scalar >
virtual std::size_t get_nh ( ) const
virtual

Return the number of equality constraints.

Reimplemented in IntegratedActionModelAbstractTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ get_ng_T()

template<typename _Scalar >
virtual std::size_t get_ng_T ( ) const
virtual

Return the number of inequality terminal constraints.

Reimplemented in IntegratedActionModelAbstractTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ get_nh_T()

template<typename _Scalar >
virtual std::size_t get_nh_T ( ) const
virtual

Return the number of equality terminal constraints.

Reimplemented in IntegratedActionModelAbstractTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ get_g_lb()

template<typename _Scalar >
virtual const VectorXs & get_g_lb ( ) const
virtual

Return the lower bound of the inequality constraints.

Reimplemented in IntegratedActionModelAbstractTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ get_g_ub()

template<typename _Scalar >
virtual const VectorXs & get_g_ub ( ) const
virtual

Return the upper bound of the inequality constraints.

Reimplemented in IntegratedActionModelAbstractTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.

◆ print()

template<typename _Scalar >
virtual void print ( std::ostream &  os) const
virtual

Friends And Related Symbol Documentation

◆ ConstraintModelManagerTpl

template<typename _Scalar >
template<class Scalar >
friend class ConstraintModelManagerTpl
friend

Definition at line 352 of file action-base.hpp.

Member Data Documentation

◆ Scalar

template<typename _Scalar >
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar Scalar

Definition at line 101 of file action-base.hpp.

◆ nu_

template<typename _Scalar >
std::size_t nu_
protected

Control dimension.

Definition at line 328 of file action-base.hpp.

◆ nr_

template<typename _Scalar >
std::size_t nr_
protected

Dimension of the cost residual.

Definition at line 329 of file action-base.hpp.

◆ ng_

template<typename _Scalar >
std::size_t ng_
protected

Number of inequality constraints.

Definition at line 330 of file action-base.hpp.

◆ nh_

template<typename _Scalar >
std::size_t nh_
protected

Number of equality constraints.

Definition at line 331 of file action-base.hpp.

◆ ng_T_

template<typename _Scalar >
std::size_t ng_T_
protected

Number of inequality terminal constraints.

Definition at line 332 of file action-base.hpp.

◆ nh_T_

template<typename _Scalar >
std::size_t nh_T_
protected

Number of equality terminal constraints.

Definition at line 333 of file action-base.hpp.

◆ state_

template<typename _Scalar >
std::shared_ptr<StateAbstract> state_
protected

Model of the state.

Definition at line 334 of file action-base.hpp.

◆ unone_

template<typename _Scalar >
VectorXs unone_
protected

Neutral state.

Definition at line 335 of file action-base.hpp.

◆ g_lb_

template<typename _Scalar >
VectorXs g_lb_
protected

Lower bound of the inequality constraints.

Definition at line 336 of file action-base.hpp.

◆ g_ub_

template<typename _Scalar >
VectorXs g_ub_
protected

Lower bound of the inequality constraints.

Definition at line 337 of file action-base.hpp.

◆ u_lb_

template<typename _Scalar >
VectorXs u_lb_
protected

Lower control limits.

Definition at line 338 of file action-base.hpp.

◆ u_ub_

template<typename _Scalar >
VectorXs u_ub_
protected

Upper control limits.

Definition at line 339 of file action-base.hpp.

◆ has_control_limits_

template<typename _Scalar >
bool has_control_limits_
protected

Indicates whether any of the control limits is finite

Definition at line 340 of file action-base.hpp.


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