Interface class for system dynamic equations. More...

#include <system_dynamics_interface.h>

Inheritance diagram for corbo::SystemDynamicsInterface:

[legend]

Public Types
using	ControlVector = Eigen::VectorXd

using	Ptr = std::shared_ptr< SystemDynamicsInterface >

using	StateVector = Eigen::VectorXd

Public Member Functions
virtual void	dynamics (const Eigen::Ref< const StateVector > &x, const Eigen::Ref< const ControlVector > &u, Eigen::Ref< StateVector > f) const =0
	Evaluate the system dynamics equation. More...

virtual double	getDeadTime () const
	Return deadtime which might be taken into account by controllers/simulators if supported. More...

virtual int	getInputDimension () const =0
	Return the plant input dimension (u) More...

virtual Ptr	getInstance () const =0
	Return a newly created shared instance of the implemented class. More...

virtual void	getLinearA (const StateVector &x0, const ControlVector &u0, Eigen::MatrixXd &A) const
	Return linear system matrix A (linearized system dynamics) More...

virtual void	getLinearB (const StateVector &x0, const ControlVector &u0, Eigen::MatrixXd &B) const
	Return linear control input matrix B (linearized system dynamics) More...

virtual int	getStateDimension () const =0
	Return state dimension (x) More...

virtual bool	isContinuousTime () const =0
	Check if the system dynamics are defined in continuous-time. More...

virtual bool	isLinear () const =0
	Check if the system dynamics are linear. More...

virtual void	reset ()

void	setLinearizationMethod (std::shared_ptr< FiniteDifferencesInterface > lin_method)
	Set linearization method in case getLinearA() or getLinearB() are not overriden. More...

	SystemDynamicsInterface ()
	Default constructor. More...

virtual	~SystemDynamicsInterface ()=default
	Default destructor. More...

Private Attributes
double	_deadtime = 0.0

std::shared_ptr< FiniteDifferencesInterface >	_linearization_method

Detailed Description

Interface class for system dynamic equations.

This class specifies methods that are required to be implemented by specific subclasses in order to allow their general utilization in a variety of control tasks.

System dynamics can be either defined in continuous-time, e.g.

$\dot{x} = f(x, u)$

or in discrete-time, e.g.

$x_{k+1} = f(x_k, u_k)$

. Subclasses must overload isContinuousTime() appropriately.

Remarks: This interface is provided with factory support (SystemDynamicsFactory).

See also: SystemOutputInterface PlantInterface

Author: Christoph Rösmann (chris.nosp@m.toph.nosp@m..roes.nosp@m.mann.nosp@m.@tu-d.nosp@m.ortm.nosp@m.und.d.nosp@m.e)

Definition at line 66 of file system_dynamics_interface.h.

Member Typedef Documentation

◆ ControlVector

using corbo::SystemDynamicsInterface::ControlVector = Eigen::VectorXd

Definition at line 71 of file system_dynamics_interface.h.

◆ Ptr

using corbo::SystemDynamicsInterface::Ptr = std::shared_ptr<SystemDynamicsInterface>

Definition at line 69 of file system_dynamics_interface.h.

◆ StateVector

using corbo::SystemDynamicsInterface::StateVector = Eigen::VectorXd

Definition at line 70 of file system_dynamics_interface.h.

Constructor & Destructor Documentation

◆ SystemDynamicsInterface()

corbo::SystemDynamicsInterface::SystemDynamicsInterface ( )

Default constructor.

Definition at line 31 of file system_dynamics_interface.cpp.

◆ ~SystemDynamicsInterface()

virtual corbo::SystemDynamicsInterface::~SystemDynamicsInterface ( )

virtualdefault

Default destructor.

Member Function Documentation

◆ dynamics()

virtual void corbo::SystemDynamicsInterface::dynamics	(	const Eigen::Ref< const StateVector > &	x,
		const Eigen::Ref< const ControlVector > &	u,
		Eigen::Ref< StateVector >	f
	)		const

pure virtual

Evaluate the system dynamics equation.

Implement this method to specify the actual system dynamics equation $\dot{x} = f(x,u)$ (continuous-time) or $x_{k+1} = f(x_k, u_k)$ (discrete-time).

Parameters

[in]	x	State vector x [getStateDimension() x 1]
[in]	u	Control input vector u [getInputDimension() x 1]
[out]	f	Resulting function value $\dot{x}$ respectively $x_{k+1}$ (f must be preallocated with dimension [getStateDimension() x 1])

Implemented in corbo::ArtsteinsCircle, corbo::ToyExample, corbo::CartPole, corbo::DoubleIntegratorDiscreteTime, corbo::MasslessPendulum, corbo::SimplePendulum, corbo::LinearStateSpaceModel, corbo::FreeSpaceRocket, corbo::ParallelIntegratorSystem, corbo::DuffingOscillator, corbo::SerialIntegratorSystem, and corbo::VanDerPolOscillator.

◆ getDeadTime()

virtual double corbo::SystemDynamicsInterface::getDeadTime ( ) const

inlinevirtual

Return deadtime which might be taken into account by controllers/simulators if supported.

Definition at line 107 of file system_dynamics_interface.h.

◆ getInputDimension()

virtual int corbo::SystemDynamicsInterface::getInputDimension ( ) const

pure virtual

Return the plant input dimension (u)

Implemented in corbo::ArtsteinsCircle, corbo::ToyExample, corbo::CartPole, corbo::DoubleIntegratorDiscreteTime, corbo::MasslessPendulum, corbo::SimplePendulum, corbo::LinearStateSpaceModel, corbo::FreeSpaceRocket, corbo::ParallelIntegratorSystem, corbo::DuffingOscillator, corbo::SerialIntegratorSystem, and corbo::VanDerPolOscillator.

◆ getInstance()

virtual Ptr corbo::SystemDynamicsInterface::getInstance ( ) const

pure virtual

Return a newly created shared instance of the implemented class.

Implemented in corbo::ArtsteinsCircle, corbo::ToyExample, corbo::CartPole, corbo::DoubleIntegratorDiscreteTime, corbo::MasslessPendulum, corbo::SimplePendulum, corbo::LinearStateSpaceModel, corbo::FreeSpaceRocket, corbo::ParallelIntegratorSystem, corbo::DuffingOscillator, corbo::SerialIntegratorSystem, and corbo::VanDerPolOscillator.

◆ getLinearA()

void corbo::SystemDynamicsInterface::getLinearA	(	const StateVector &	x0,
		const ControlVector &	u0,
		Eigen::MatrixXd &	A
	)		const

virtual

Return linear system matrix A (linearized system dynamics)

Linearizes the system dynamics equation $\dot{x} = f(x,u)$ (cont. case) specified with dynamics() using finite differences (refer to setLinearizationMethod()). The linearizes system dynamics at x=x0 and u=u0 are defined as:

$\dot{x} = A x + B u$

And for the discrete-time case:

$x_{k+1} = A x_k + B u_k$

. This method returns matrix $ A $ . For matrix $ B $ refer to getLinearB().

Remarks: This method might be overriden in order to specify analytically derived matrices.

Parameters

[in]	x0	State at which the system dynamics should be linearized [getStateDimension() x 1]
[in]	u0	Control input at which the dynamics should be linearized [getInputDimension() x 1]
[out]	A	Linear system matrix A [getStateDimension() x getStateDimension()] (must be preallocated)

Definition at line 33 of file system_dynamics_interface.cpp.

◆ getLinearB()

void corbo::SystemDynamicsInterface::getLinearB	(	const StateVector &	x0,
		const ControlVector &	u0,
		Eigen::MatrixXd &	B
	)		const

virtual

Return linear control input matrix B (linearized system dynamics)

Refer to the description of method getLinearA().

Remarks: This method might be overriden in order to specify analytically derived matrices.

Parameters

[in]	x0	State at which the system dynamics should be linearized [getStateDimension() x 1]
[in]	u0	Control input at which the dynamics should be linearized [getInputDimension() x 1]
[out]	B	Linear input matrix B [getStateDimension() x getInputDimension()] (must be preallocated)

Definition at line 47 of file system_dynamics_interface.cpp.

◆ getStateDimension()

virtual int corbo::SystemDynamicsInterface::getStateDimension ( ) const

pure virtual

Return state dimension (x)

Implemented in corbo::ArtsteinsCircle, corbo::ToyExample, corbo::CartPole, corbo::DoubleIntegratorDiscreteTime, corbo::MasslessPendulum, corbo::SimplePendulum, corbo::LinearStateSpaceModel, corbo::FreeSpaceRocket, corbo::ParallelIntegratorSystem, corbo::DuffingOscillator, corbo::SerialIntegratorSystem, and corbo::VanDerPolOscillator.

◆ isContinuousTime()

virtual bool corbo::SystemDynamicsInterface::isContinuousTime ( ) const

pure virtual

Check if the system dynamics are defined in continuous-time.

Continous-time equations are defined as $\dot{x} = f(x,u)$ and discrete-time equations as $x_{k+1} = f(x_k,u_k)$ .

Returns: true if the system is specified in continuous time, false otherwise.

Implemented in corbo::ArtsteinsCircle, corbo::ToyExample, corbo::CartPole, corbo::DoubleIntegratorDiscreteTime, corbo::MasslessPendulum, corbo::SimplePendulum, corbo::LinearStateSpaceModel, corbo::FreeSpaceRocket, corbo::ParallelIntegratorSystem, corbo::DuffingOscillator, corbo::SerialIntegratorSystem, and corbo::VanDerPolOscillator.

◆ isLinear()

virtual bool corbo::SystemDynamicsInterface::isLinear ( ) const

pure virtual

Check if the system dynamics are linear.

Linear system can be written in the form $\dot{x} = Ax + Bu$ (continuous-time) or $x_{k+1} = A x_k + B u_k$ (discrete-time). Consequently, getLinearA() and getLinearB() are independet of x0 and u0.

Returns: true if the system behavior is linear, false otherwise.

Implemented in corbo::ArtsteinsCircle, corbo::ToyExample, corbo::CartPole, corbo::DoubleIntegratorDiscreteTime, corbo::MasslessPendulum, corbo::SimplePendulum, corbo::LinearStateSpaceModel, corbo::FreeSpaceRocket, corbo::ParallelIntegratorSystem, corbo::DuffingOscillator, corbo::SerialIntegratorSystem, and corbo::VanDerPolOscillator.

◆ reset()

virtual void corbo::SystemDynamicsInterface::reset ( )

inlinevirtual

Definition at line 165 of file system_dynamics_interface.h.

◆ setLinearizationMethod()

void corbo::SystemDynamicsInterface::setLinearizationMethod ( std::shared_ptr< FiniteDifferencesInterface > lin_method )

Set linearization method in case getLinearA() or getLinearB() are not overriden.

Parameters

[in] lin_method shared instance of a FiniteDifferencesInterface implementation

Definition at line 61 of file system_dynamics_interface.cpp.

Member Data Documentation

◆ _deadtime

double corbo::SystemDynamicsInterface::_deadtime = 0.0

private

Definition at line 176 of file system_dynamics_interface.h.

◆ _linearization_method

std::shared_ptr<FiniteDifferencesInterface> corbo::SystemDynamicsInterface::_linearization_method

private

Definition at line 175 of file system_dynamics_interface.h.

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

Public Types

Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ ControlVector

◆ Ptr

◆ StateVector

Constructor & Destructor Documentation

◆ SystemDynamicsInterface()

◆ ~SystemDynamicsInterface()

Member Function Documentation

◆ dynamics()

◆ getDeadTime()

◆ getInputDimension()

◆ getInstance()

◆ getLinearA()

◆ getLinearB()

◆ getStateDimension()

◆ isContinuousTime()

◆ isLinear()

◆ reset()

◆ setLinearizationMethod()

Member Data Documentation

◆ _deadtime

◆ _linearization_method