Abstract class for action model. More...
#include <crocoddyl/core/action-base.hpp>
Public Types | |
typedef ActionDataAbstractTpl< Scalar > | ActionDataAbstract |
typedef MathBaseTpl< Scalar > | MathBase |
typedef StateAbstractTpl< Scalar > | StateAbstract |
typedef MathBase::VectorXs | VectorXs |
Public Member Functions | |
ActionModelAbstractTpl (boost::shared_ptr< StateAbstract > state, const std::size_t nu, const std::size_t nr=0) | |
Initialize the action model. More... | |
virtual void | calc (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x) |
Compute the total cost value for nodes that depends only on the state. More... | |
virtual void | calc (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)=0 |
Compute the next state and cost value. More... | |
virtual void | calcDiff (const boost::shared_ptr< ActionDataAbstract > &data, const Eigen::Ref< const VectorXs > &x) |
Compute the derivatives of the cost functions with respect to the state only. More... | |
virtual void | calcDiff (const boost::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. More... | |
virtual bool | checkData (const boost::shared_ptr< ActionDataAbstract > &data) |
Checks that a specific data belongs to this model. More... | |
virtual boost::shared_ptr< ActionDataAbstract > | createData () |
Create the action data. 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. | |
virtual void | print (std::ostream &os) const |
Print relevant information of the action model. More... | |
virtual void | quasiStatic (const boost::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. More... | |
VectorXs | quasiStatic_x (const boost::shared_ptr< ActionDataAbstract > &data, const VectorXs &x, const std::size_t maxiter=100, const Scalar tol=Scalar(1e-9)) |
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 | |
bool | has_control_limits_ |
Indicates whether any of the control limits is finite. More... | |
std::size_t | nr_ |
Dimension of the cost residual. More... | |
std::size_t | nu_ |
Control dimension. More... | |
boost::shared_ptr< StateAbstract > | state_ |
Model of the state. More... | |
VectorXs | u_lb_ |
Lower control limits. More... | |
VectorXs | u_ub_ |
Upper control limits. More... | |
VectorXs | unone_ |
Neutral state. More... | |
Friends | |
template<class Scalar > | |
std::ostream & | operator<< (std::ostream &os, const ActionModelAbstractTpl< Scalar > &model) |
Print information on the action model. | |
Abstract class for action model.
An action model combines dynamics and cost models. 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 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.
\[ \begin{aligned} &\delta\mathbf{x}^+ = \mathbf{f_{x}}\delta\mathbf{x}+\mathbf{f_{u}}\delta\mathbf{u}, &\textrm{(dynamics)}\\ &l(\delta\mathbf{x},\delta\mathbf{u}) = \begin{bmatrix}1 \\ \delta\mathbf{x} \\ \delta\mathbf{u}\end{bmatrix}^T \begin{bmatrix}0 & \mathbf{l_x}^T & \mathbf{l_u}^T \\ \mathbf{l_x} & \mathbf{l_{xx}} & \mathbf{l_{ux}}^T \\ \mathbf{l_u} & \mathbf{l_{ux}} & \mathbf{l_{uu}}\end{bmatrix} \begin{bmatrix}1 \\ \delta\mathbf{x} \\ \delta\mathbf{u}\end{bmatrix}, &\textrm{(cost)} \end{aligned} \]
where the state \(\mathbf{x}\in\mathcal{X}\) lies in the state manifold described with a nx
-tuple, its rate \(\delta\mathbf{x}\in T_{\mathbf{x}}\mathcal{X}\) is a tangent vector to this manifold with ndx
dimension, and \(\mathbf{u}\in\mathbb{R}^{nu}\) is the input commands. Note that the we could describe a linear or linearized action system, where the cost has a quadratic form.
The main computations are carrying out in calc
and calcDiff
. calc
computes the next state and cost and calcDiff
computes the derivatives of the dynamics and cost function. Concretely speaking, calcDiff
builds a linear-quadratic approximation of an action model, where the dynamics and cost functions have linear and quadratic forms, respectively. \(\mathbf{f_x}\in\mathbb{R}^{nv\times ndx}\), \(\mathbf{f_u}\in\mathbb{R}^{nv\times nu}\) are the Jacobians of the dynamics; \(\mathbf{l_x}\in\mathbb{R}^{ndx}\), \(\mathbf{l_u}\in\mathbb{R}^{nu}\), \(\mathbf{l_{xx}}\in\mathbb{R}^{ndx\times ndx}\), \(\mathbf{l_{xu}}\in\mathbb{R}^{ndx\times nu}\), \(\mathbf{l_{uu}}\in\mathbb{R}^{nu\times nu}\) are the Jacobians and Hessians of the cost function, respectively. Additionally, it is important remark that calcDiff()
computes the derivates using the latest stored values by calc()
. Thus, we need to run first calc()
.
calc()
, calcDiff()
, createData()
Definition at line 59 of file action-base.hpp.
typedef MathBaseTpl<Scalar> MathBase |
Definition at line 64 of file action-base.hpp.
typedef ActionDataAbstractTpl<Scalar> ActionDataAbstract |
Definition at line 65 of file action-base.hpp.
typedef StateAbstractTpl<Scalar> StateAbstract |
Definition at line 66 of file action-base.hpp.
typedef MathBase::VectorXs VectorXs |
Definition at line 67 of file action-base.hpp.
ActionModelAbstractTpl | ( | boost::shared_ptr< StateAbstract > | state, |
const std::size_t | nu, | ||
const std::size_t | nr = 0 |
||
) |
Initialize the action model.
[in] | state | State description |
[in] | nu | Dimension of control vector |
[in] | nr | Dimension of cost-residual vector |
|
pure virtual |
Compute the next state and cost value.
[in] | data | Action data |
[in] | x | State point \(\mathbf{x}\in\mathbb{R}^{ndx}\) |
[in] | u | Control input \(\mathbf{u}\in\mathbb{R}^{nu}\) |
Implemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, IntegratedActionModelRK4Tpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.
|
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.
[in] | data | Action data |
[in] | x | State point \(\mathbf{x}\in\mathbb{R}^{ndx}\) |
Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and IntegratedActionModelRK4Tpl< _Scalar >.
|
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).
[in] | data | Action data |
[in] | x | State point \(\mathbf{x}\in\mathbb{R}^{ndx}\) |
[in] | u | Control input \(\mathbf{u}\in\mathbb{R}^{nu}\) |
Implemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, IntegratedActionModelRK4Tpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.
|
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.
[in] | data | Action data |
[in] | x | State point \(\mathbf{x}\in\mathbb{R}^{ndx}\) |
Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and IntegratedActionModelRK4Tpl< _Scalar >.
|
virtual |
Create the action data.
Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, ActionModelCodeGenTpl< _Scalar >, IntegratedActionModelAbstractTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, IntegratedActionModelRK4Tpl< _Scalar >, ActionModelNumDiffTpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.
|
virtual |
Checks that a specific data belongs to this model.
Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, IntegratedActionModelRK4Tpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.
|
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 \(\mathbf{f^q_x}\delta\mathbf{q}+\mathbf{f_u}\delta\mathbf{u}=\mathbf{0}\)
[in] | data | 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 in IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, and IntegratedActionModelRK4Tpl< _Scalar >.
VectorXs quasiStatic_x | ( | const boost::shared_ptr< ActionDataAbstract > & | data, |
const VectorXs & | x, | ||
const std::size_t | maxiter = 100 , |
||
const Scalar | tol = Scalar(1e-9) |
||
) |
[in] | data | Action data |
[in] | x | State point (velocity has to be zero) |
[in] | maxiter | Maximum allowed number of iterations |
[in] | tol | Tolerance |
|
virtual |
Print relevant information of the action model.
[out] | os | Output stream object |
Reimplemented in ActionModelLQRTpl< _Scalar >, ActionModelUnicycleTpl< _Scalar >, IntegratedActionModelEulerTpl< _Scalar >, IntegratedActionModelRKTpl< _Scalar >, IntegratedActionModelRK4Tpl< _Scalar >, and ActionModelImpulseFwdDynamicsTpl< _Scalar >.
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar Scalar |
Definition at line 63 of file action-base.hpp.
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protected |
Control dimension.
Definition at line 221 of file action-base.hpp.
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protected |
Dimension of the cost residual.
Definition at line 222 of file action-base.hpp.
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protected |
Model of the state.
Definition at line 223 of file action-base.hpp.
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protected |
Neutral state.
Definition at line 224 of file action-base.hpp.
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protected |
Lower control limits.
Definition at line 225 of file action-base.hpp.
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protected |
Upper control limits.
Definition at line 226 of file action-base.hpp.
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protected |
Indicates whether any of the control limits is finite.
Definition at line 227 of file action-base.hpp.