Represents a simulated arm mechanism. More...

#include <frc/simulation/SingleJointedArmSim.h>

Inheritance diagram for frc::sim::SingleJointedArmSim:

Public Member Functions
	SingleJointedArmSim (const LinearSystem< 2, 1, 2 > &system, const DCMotor &gearbox, double gearing, units::meter_t armLength, units::radian_t minAngle, units::radian_t maxAngle, bool simulateGravity, units::radian_t startingAngle, const std::array< double, 2 > &measurementStdDevs={0.0, 0.0})
	Creates a simulated arm mechanism.

	SingleJointedArmSim (const DCMotor &gearbox, double gearing, units::kilogram_square_meter_t moi, units::meter_t armLength, units::radian_t minAngle, units::radian_t maxAngle, bool simulateGravity, units::radian_t startingAngle, const std::array< double, 2 > &measurementStdDevs={0.0, 0.0})
	Creates a simulated arm mechanism.

void	SetState (units::radian_t angle, units::radians_per_second_t velocity)
	Sets the arm's state.

bool	WouldHitLowerLimit (units::radian_t armAngle) const
	Returns whether the arm would hit the lower limit.

bool	WouldHitUpperLimit (units::radian_t armAngle) const
	Returns whether the arm would hit the upper limit.

bool	HasHitLowerLimit () const
	Returns whether the arm has hit the lower limit.

bool	HasHitUpperLimit () const
	Returns whether the arm has hit the upper limit.

units::radian_t	GetAngle () const
	Returns the current arm angle.

units::radians_per_second_t	GetVelocity () const
	Returns the current arm velocity.

units::ampere_t	GetCurrentDraw () const
	Returns the arm current draw.

void	SetInputVoltage (units::volt_t voltage)
	Sets the input voltage for the arm.

void	SetState (const Vectord< States > &state)
	Sets the system state.

Public Member Functions inherited from frc::sim::LinearSystemSim< 2, 1, 2 >
	LinearSystemSim (const LinearSystem< States, Inputs, Outputs > &system, const std::array< double, Outputs > &measurementStdDevs={})
	Creates a simulated generic linear system.

virtual	~LinearSystemSim ()=default

void	Update (units::second_t dt)
	Updates the simulation.

const Vectord< Outputs > &	GetOutput () const
	Returns the current output of the plant.

double	GetOutput (int row) const
	Returns an element of the current output of the plant.

void	SetInput (const Vectord< Inputs > &u)
	Sets the system inputs (usually voltages).

void	SetInput (int row, double value)
	Sets the system inputs.

const Vectord< Inputs > &	GetInput () const
	Returns the current input of the plant.

double	GetInput (int row) const
	Returns an element of the current input of the plant.

void	SetState (const Vectord< States > &state)
	Sets the system state.

Static Public Member Functions
static constexpr units::kilogram_square_meter_t	EstimateMOI (units::meter_t length, units::kilogram_t mass)
	Calculates a rough estimate of the moment of inertia of an arm given its length and mass.

Protected Member Functions
Vectord< 2 >	UpdateX (const Vectord< 2 > &currentXhat, const Vectord< 1 > &u, units::second_t dt) override
	Updates the state estimate of the arm.

Protected Member Functions inherited from frc::sim::LinearSystemSim< 2, 1, 2 >
virtual Vectord< States >	UpdateX (const Vectord< States > &currentXhat, const Vectord< Inputs > &u, units::second_t dt)
	Updates the state estimate of the system.

void	ClampInput (double maxInput)
	Clamp the input vector such that no element exceeds the given voltage.

Additional Inherited Members
Protected Attributes inherited from frc::sim::LinearSystemSim< 2, 1, 2 >
LinearSystem< States, Inputs, Outputs >	m_plant
	The plant that represents the linear system.

Vectord< States >	m_x
	State vector.

Vectord< Inputs >	m_u
	Input vector.

Vectord< Outputs >	m_y
	Output vector.

std::array< double, Outputs >	m_measurementStdDevs
	The standard deviations of measurements, used for adding noise to the measurements.

Detailed Description

Represents a simulated arm mechanism.

Constructor & Destructor Documentation

◆ SingleJointedArmSim() [1/2]

frc::sim::SingleJointedArmSim::SingleJointedArmSim	(	const LinearSystem< 2, 1, 2 > &	system,
		const DCMotor &	gearbox,
		double	gearing,
		units::meter_t	armLength,
		units::radian_t	minAngle,
		units::radian_t	maxAngle,
		bool	simulateGravity,
		units::radian_t	startingAngle,
		const std::array< double, 2 > &	measurementStdDevs = {0.0, 0.0} )

Creates a simulated arm mechanism.

Parameters

system	The system representing this arm. This system can be created with LinearSystemId::SingleJointedArmSystem().
gearbox	The type and number of motors on the arm gearbox.
gearing	The gear ratio of the arm (numbers greater than 1 represent reductions).
armLength	The length of the arm.
minAngle	The minimum angle that the arm is capable of.
maxAngle	The maximum angle that the arm is capable of.
simulateGravity	Whether gravity should be simulated or not.
startingAngle	The initial position of the arm.
measurementStdDevs	The standard deviations of the measurements.

◆ SingleJointedArmSim() [2/2]

frc::sim::SingleJointedArmSim::SingleJointedArmSim	(	const DCMotor &	gearbox,
		double	gearing,
		units::kilogram_square_meter_t	moi,
		units::meter_t	armLength,
		units::radian_t	minAngle,
		units::radian_t	maxAngle,
		bool	simulateGravity,
		units::radian_t	startingAngle,
		const std::array< double, 2 > &	measurementStdDevs = {0.0, 0.0} )

Creates a simulated arm mechanism.

Parameters

gearbox	The type and number of motors on the arm gearbox.
gearing	The gear ratio of the arm (numbers greater than 1 represent reductions).
moi	The moment of inertia of the arm. This can be calculated from CAD software.
armLength	The length of the arm.
minAngle	The minimum angle that the arm is capable of.
maxAngle	The maximum angle that the arm is capable of.
simulateGravity	Whether gravity should be simulated or not.
startingAngle	The initial position of the arm.
measurementStdDevs	The standard deviation of the measurement noise.

Member Function Documentation

◆ EstimateMOI()

static constexpr units::kilogram_square_meter_t frc::sim::SingleJointedArmSim::EstimateMOI	(	units::meter_t	length,
		units::kilogram_t	mass )

inlinestaticconstexpr

Calculates a rough estimate of the moment of inertia of an arm given its length and mass.

Parameters

length	The length of the arm.
mass	The mass of the arm.

Returns: The calculated moment of inertia.

◆ GetAngle()

units::radian_t frc::sim::SingleJointedArmSim::GetAngle ( ) const

Returns the current arm angle.

Returns: The current arm angle.

◆ GetCurrentDraw()

units::ampere_t frc::sim::SingleJointedArmSim::GetCurrentDraw ( ) const

Returns the arm current draw.

Returns: The arm current draw.

◆ GetVelocity()

units::radians_per_second_t frc::sim::SingleJointedArmSim::GetVelocity ( ) const

Returns the current arm velocity.

Returns: The current arm velocity.

◆ HasHitLowerLimit()

bool frc::sim::SingleJointedArmSim::HasHitLowerLimit ( ) const

Returns whether the arm has hit the lower limit.

Returns: Whether the arm has hit the lower limit.

◆ HasHitUpperLimit()

bool frc::sim::SingleJointedArmSim::HasHitUpperLimit ( ) const

Returns whether the arm has hit the upper limit.

Returns: Whether the arm has hit the upper limit.

◆ SetInputVoltage()

void frc::sim::SingleJointedArmSim::SetInputVoltage ( units::volt_t voltage )

Sets the input voltage for the arm.

Parameters

voltage The input voltage.

◆ SetState() [1/2]

void frc::sim::LinearSystemSim< States, Inputs, Outputs >::SetState ( const Vectord< States > & state )

inline

Sets the system state.

Parameters

state The new state.

◆ SetState() [2/2]

void frc::sim::SingleJointedArmSim::SetState	(	units::radian_t	angle,
		units::radians_per_second_t	velocity )

Sets the arm's state.

The new angle will be limited between the minimum and maximum allowed limits.

Parameters

angle	The new angle.
velocity	The new angular velocity.

◆ UpdateX()

Vectord< 2 > frc::sim::SingleJointedArmSim::UpdateX	(	const Vectord< 2 > &	currentXhat,
		const Vectord< 1 > &	u,
		units::second_t	dt )

overrideprotected

Updates the state estimate of the arm.

Parameters

currentXhat	The current state estimate.
u	The system inputs (voltage).
dt	The time difference between controller updates.

◆ WouldHitLowerLimit()

bool frc::sim::SingleJointedArmSim::WouldHitLowerLimit ( units::radian_t armAngle ) const

Returns whether the arm would hit the lower limit.

Parameters

armAngle The arm height.

Returns: Whether the arm would hit the lower limit.

◆ WouldHitUpperLimit()

bool frc::sim::SingleJointedArmSim::WouldHitUpperLimit ( units::radian_t armAngle ) const

Returns whether the arm would hit the upper limit.

Parameters

armAngle The arm height.

Returns: Whether the arm would hit the upper limit.

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

frc/simulation/SingleJointedArmSim.h

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SingleJointedArmSim() [1/2]

◆ SingleJointedArmSim() [2/2]

Member Function Documentation

◆ EstimateMOI()

◆ GetAngle()

◆ GetCurrentDraw()

◆ GetVelocity()

◆ HasHitLowerLimit()

◆ HasHitUpperLimit()

◆ SetInputVoltage()

◆ SetState() [1/2]

◆ SetState() [2/2]

◆ UpdateX()

◆ WouldHitLowerLimit()

◆ WouldHitUpperLimit()