A plant defined using state-space notation. More...

#include <frc/system/LinearSystem.h>

Public Types
using	StateVector = Vectord<States>

using	InputVector = Vectord<Inputs>

using	OutputVector = Vectord<Outputs>

Public Member Functions
constexpr	LinearSystem (const Matrixd< States, States > &A, const Matrixd< States, Inputs > &B, const Matrixd< Outputs, States > &C, const Matrixd< Outputs, Inputs > &D)
	Constructs a discrete plant with the given continuous system coefficients.

constexpr	LinearSystem (const LinearSystem &)=default

constexpr LinearSystem &	operator= (const LinearSystem &)=default

constexpr	LinearSystem (LinearSystem &&)=default

constexpr LinearSystem &	operator= (LinearSystem &&)=default

constexpr const Matrixd< States, States > &	A () const
	Returns the system matrix A.

constexpr double	A (int i, int j) const
	Returns an element of the system matrix A.

constexpr const Matrixd< States, Inputs > &	B () const
	Returns the input matrix B.

constexpr double	B (int i, int j) const
	Returns an element of the input matrix B.

constexpr const Matrixd< Outputs, States > &	C () const
	Returns the output matrix C.

constexpr double	C (int i, int j) const
	Returns an element of the output matrix C.

constexpr const Matrixd< Outputs, Inputs > &	D () const
	Returns the feedthrough matrix D.

constexpr double	D (int i, int j) const
	Returns an element of the feedthrough matrix D.

StateVector	CalculateX (const StateVector &x, const InputVector &clampedU, units::second_t dt) const
	Computes the new x given the old x and the control input.

OutputVector	CalculateY (const StateVector &x, const InputVector &clampedU) const
	Computes the new y given the control input.

template<std::same_as< int >... OutputIndices>
LinearSystem< States, Inputs, sizeof...(OutputIndices)>	Slice (OutputIndices... outputIndices)
	Returns the LinearSystem with the outputs listed in outputIndices.

Detailed Description

template<int States, int Inputs, int Outputs>
class frc::LinearSystem< States, Inputs, Outputs >

A plant defined using state-space notation.

A plant is a mathematical model of a system's dynamics.

For more on the underlying math, read https://file.tavsys.net/control/controls-engineering-in-frc.pdf.

Template Parameters

States	Number of states.
Inputs	Number of inputs.
Outputs	Number of outputs.

Member Typedef Documentation

◆ InputVector

template<int States, int Inputs, int Outputs>

using frc::LinearSystem< States, Inputs, Outputs >::InputVector = Vectord<Inputs>

◆ OutputVector

template<int States, int Inputs, int Outputs>

using frc::LinearSystem< States, Inputs, Outputs >::OutputVector = Vectord<Outputs>

◆ StateVector

template<int States, int Inputs, int Outputs>

using frc::LinearSystem< States, Inputs, Outputs >::StateVector = Vectord<States>

Constructor & Destructor Documentation

◆ LinearSystem() [1/3]

template<int States, int Inputs, int Outputs>

frc::LinearSystem< States, Inputs, Outputs >::LinearSystem	(	const Matrixd< States, States > &	A,
		const Matrixd< States, Inputs > &	B,
		const Matrixd< Outputs, States > &	C,
		const Matrixd< Outputs, Inputs > &	D )

inlineconstexpr

Constructs a discrete plant with the given continuous system coefficients.

Parameters

A	System matrix.
B	Input matrix.
C	Output matrix.
D	Feedthrough matrix.

Throws:: std::domain_error if any matrix element isn't finite.

◆ LinearSystem() [2/3]

template<int States, int Inputs, int Outputs>

frc::LinearSystem< States, Inputs, Outputs >::LinearSystem ( const LinearSystem< States, Inputs, Outputs > & )

constexprdefault

◆ LinearSystem() [3/3]

template<int States, int Inputs, int Outputs>

frc::LinearSystem< States, Inputs, Outputs >::LinearSystem ( LinearSystem< States, Inputs, Outputs > && )

constexprdefault

Member Function Documentation

◆ A() [1/2]

template<int States, int Inputs, int Outputs>

const Matrixd< States, States > & frc::LinearSystem< States, Inputs, Outputs >::A ( ) const

inlineconstexpr

Returns the system matrix A.

◆ A() [2/2]

template<int States, int Inputs, int Outputs>

double frc::LinearSystem< States, Inputs, Outputs >::A	(	int	i,
		int	j ) const

inlineconstexpr

Returns an element of the system matrix A.

Parameters

i	Row of A.
j	Column of A.

◆ B() [1/2]

template<int States, int Inputs, int Outputs>

const Matrixd< States, Inputs > & frc::LinearSystem< States, Inputs, Outputs >::B ( ) const

inlineconstexpr

Returns the input matrix B.

◆ B() [2/2]

template<int States, int Inputs, int Outputs>

double frc::LinearSystem< States, Inputs, Outputs >::B	(	int	i,
		int	j ) const

inlineconstexpr

Returns an element of the input matrix B.

Parameters

i	Row of B.
j	Column of B.

◆ C() [1/2]

template<int States, int Inputs, int Outputs>

const Matrixd< Outputs, States > & frc::LinearSystem< States, Inputs, Outputs >::C ( ) const

inlineconstexpr

Returns the output matrix C.

◆ C() [2/2]

template<int States, int Inputs, int Outputs>

double frc::LinearSystem< States, Inputs, Outputs >::C	(	int	i,
		int	j ) const

inlineconstexpr

Returns an element of the output matrix C.

Parameters

i	Row of C.
j	Column of C.

◆ CalculateX()

template<int States, int Inputs, int Outputs>

StateVector frc::LinearSystem< States, Inputs, Outputs >::CalculateX	(	const StateVector &	x,
		const InputVector &	clampedU,
		units::second_t	dt ) const

inline

Computes the new x given the old x and the control input.

This is used by state observers directly to run updates based on state estimate.

Parameters

x	The current state.
clampedU	The control input.
dt	Timestep for model update.

◆ CalculateY()

template<int States, int Inputs, int Outputs>

OutputVector frc::LinearSystem< States, Inputs, Outputs >::CalculateY	(	const StateVector &	x,
		const InputVector &	clampedU ) const

inline

Computes the new y given the control input.

This is used by state observers directly to run updates based on state estimate.

Parameters

x	The current state.
clampedU	The control input.

◆ D() [1/2]

template<int States, int Inputs, int Outputs>

const Matrixd< Outputs, Inputs > & frc::LinearSystem< States, Inputs, Outputs >::D ( ) const

inlineconstexpr

Returns the feedthrough matrix D.

◆ D() [2/2]

template<int States, int Inputs, int Outputs>

double frc::LinearSystem< States, Inputs, Outputs >::D	(	int	i,
		int	j ) const

inlineconstexpr

Returns an element of the feedthrough matrix D.

Parameters

i	Row of D.
j	Column of D.

◆ operator=() [1/2]

template<int States, int Inputs, int Outputs>

LinearSystem & frc::LinearSystem< States, Inputs, Outputs >::operator= ( const LinearSystem< States, Inputs, Outputs > & )

constexprdefault

◆ operator=() [2/2]

template<int States, int Inputs, int Outputs>

LinearSystem & frc::LinearSystem< States, Inputs, Outputs >::operator= ( LinearSystem< States, Inputs, Outputs > && )

constexprdefault

◆ Slice()

template<int States, int Inputs, int Outputs>

template<std::same_as< int >... OutputIndices>

LinearSystem< States, Inputs, sizeof...(OutputIndices)> frc::LinearSystem< States, Inputs, Outputs >::Slice ( OutputIndices... outputIndices )

inline

Returns the LinearSystem with the outputs listed in outputIndices.

This is used by state observers such as the Kalman Filter.

Parameters

outputIndices the list of output indices to include in the sliced system.

Returns: the sliced LinearSystem with outputs set to row vectors of LinearSystem.

Throws:: std::domain_error if any outputIndices are outside the range of system outputs.

Throws:: std::domain_error if number of outputIndices exceeds the system outputs.

Throws:: std::domain_error if duplication exists in outputIndices.

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

frc/system/LinearSystem.h

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ InputVector

◆ OutputVector

◆ StateVector

Constructor & Destructor Documentation

◆ LinearSystem() [1/3]

◆ LinearSystem() [2/3]

◆ LinearSystem() [3/3]

Member Function Documentation

◆ A() [1/2]

◆ A() [2/2]

◆ B() [1/2]

◆ B() [2/2]

◆ C() [1/2]

◆ C() [2/2]

◆ CalculateX()

◆ CalculateY()

◆ D() [1/2]

◆ D() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Slice()