frc::Pose2d Class Reference

Represents a 2D pose containing translational and rotational elements. More...

#include <frc/geometry/Pose2d.h>

Public Member Functions
constexpr	Pose2d ()=default
	Constructs a pose at the origin facing toward the positive X axis.
constexpr	Pose2d (Translation2d translation, Rotation2d rotation)
	Constructs a pose with the specified translation and rotation.
constexpr	Pose2d (units::meter_t x, units::meter_t y, Rotation2d rotation)
	Constructs a pose with x and y translations instead of a separate Translation2d.
constexpr	Pose2d (const Eigen::Matrix3d &matrix)
	Constructs a pose with the specified affine transformation matrix.
constexpr Pose2d	operator+ (const Transform2d &other) const
	Transforms the pose by the given transformation and returns the new transformed pose.
constexpr Transform2d	operator- (const Pose2d &other) const
	Returns the Transform2d that maps the one pose to another.
constexpr bool	operator== (const Pose2d &) const =default
	Checks equality between this Pose2d and another object.
constexpr const Translation2d &	Translation () const
	Returns the underlying translation.
constexpr units::meter_t	X () const
	Returns the X component of the pose's translation.
constexpr units::meter_t	Y () const
	Returns the Y component of the pose's translation.
constexpr const Rotation2d &	Rotation () const
	Returns the underlying rotation.
constexpr Pose2d	operator* (double scalar) const
	Multiplies the current pose by a scalar.
constexpr Pose2d	operator/ (double scalar) const
	Divides the current pose by a scalar.
constexpr Pose2d	RotateBy (const Rotation2d &other) const
	Rotates the pose around the origin and returns the new pose.
constexpr Pose2d	TransformBy (const Transform2d &other) const
	Transforms the pose by the given transformation and returns the new pose.
constexpr Pose2d	RelativeTo (const Pose2d &other) const
	Returns the current pose relative to the given pose.
constexpr Pose2d	RotateAround (const Translation2d &point, const Rotation2d &rot) const
	Rotates the current pose around a point in 2D space.
constexpr Pose2d	Exp (const Twist2d &twist) const
	Obtain a new Pose2d from a (constant curvature) velocity.
constexpr Twist2d	Log (const Pose2d &end) const
	Returns a Twist2d that maps this pose to the end pose.
constexpr Eigen::Matrix3d	ToMatrix () const
	Returns an affine transformation matrix representation of this pose.
constexpr Pose2d	Nearest (std::span< const Pose2d > poses) const
	Returns the nearest Pose2d from a collection of poses.
constexpr Pose2d	Nearest (std::initializer_list< Pose2d > poses) const
	Returns the nearest Pose2d from a collection of poses.

Detailed Description

Represents a 2D pose containing translational and rotational elements.

Constructor & Destructor Documentation

Pose2d() [1/4]

frc::Pose2d::Pose2d ( )

constexprdefault

Constructs a pose at the origin facing toward the positive X axis.

Pose2d() [2/4]

frc::Pose2d::Pose2d ( Translation2d translation, Rotation2d rotation )

inlineconstexpr

Constructs a pose with the specified translation and rotation.

Parameters

translation	The translational component of the pose.
rotation	The rotational component of the pose.

Pose2d() [3/4]

frc::Pose2d::Pose2d ( units::meter_t x, units::meter_t y, Rotation2d rotation )

inlineconstexpr

Constructs a pose with x and y translations instead of a separate Translation2d.

Parameters

x	The x component of the translational component of the pose.
y	The y component of the translational component of the pose.
rotation	The rotational component of the pose.

Pose2d() [4/4]

frc::Pose2d::Pose2d ( const Eigen::Matrix3d & matrix )

inlineexplicitconstexpr

Constructs a pose with the specified affine transformation matrix.

Parameters

matrix

The affine transformation matrix.

Throws:

std::domain_error if the affine transformation matrix is invalid.

Member Function Documentation

Exp()

Pose2d frc::Pose2d::Exp ( const Twist2d & twist ) const

constexpr

Obtain a new Pose2d from a (constant curvature) velocity.

See https://file.tavsys.net/control/controls-engineering-in-frc.pdf section 10.2 "Pose exponential" for a derivation.

The twist is a change in pose in the robot's coordinate frame since the previous pose update. When the user runs exp() on the previous known field-relative pose with the argument being the twist, the user will receive the new field-relative pose.

"Exp" represents the pose exponential, which is solving a differential equation moving the pose forward in time.

Parameters

twist

The change in pose in the robot's coordinate frame since the previous pose update. For example, if a non-holonomic robot moves forward 0.01 meters and changes angle by 0.5 degrees since the previous pose update, the twist would be Twist2d{0.01_m, 0_m, 0.5_deg}.

Returns

The new pose of the robot.

Log()

Twist2d frc::Pose2d::Log ( const Pose2d & end ) const

constexpr

Returns a Twist2d that maps this pose to the end pose.

If c is the output of a.Log(b), then a.Exp(c) would yield b.

Parameters

end	The end pose for the transformation.

Returns

The twist that maps this to end.

Nearest() [1/2]

Pose2d frc::Pose2d::Nearest ( std::initializer_list< Pose2d > poses ) const

inlineconstexpr

Returns the nearest Pose2d from a collection of poses.

Parameters

poses

The collection of poses.

Returns

The nearest Pose2d from the collection.

Nearest() [2/2]

Pose2d frc::Pose2d::Nearest ( std::span< const Pose2d > poses ) const

inlineconstexpr

Returns the nearest Pose2d from a collection of poses.

Parameters

poses

The collection of poses.

Returns

The nearest Pose2d from the collection.

operator*()

Pose2d frc::Pose2d::operator* ( double scalar ) const

inlineconstexpr

Multiplies the current pose by a scalar.

Parameters

scalar

The scalar.

Returns

The new scaled Pose2d.

operator+()

Pose2d frc::Pose2d::operator+ ( const Transform2d & other ) const

inlineconstexpr

Transforms the pose by the given transformation and returns the new transformed pose.

[x_new]    [cos, -sin, 0][transform.x]
[y_new] += [sin,  cos, 0][transform.y]
[t_new]    [  0,    0, 1][transform.t]

Parameters

other

The transform to transform the pose by.

Returns

The transformed pose.

operator-()

Transform2d frc::Pose2d::operator- ( const Pose2d & other ) const

constexpr

Returns the Transform2d that maps the one pose to another.

Parameters

other

The initial pose of the transformation.

Returns

The transform that maps the other pose to the current pose.

operator/()

Pose2d frc::Pose2d::operator/ ( double scalar ) const

inlineconstexpr

Divides the current pose by a scalar.

Parameters

scalar

The scalar.

Returns

The new scaled Pose2d.

operator==()

bool frc::Pose2d::operator== ( const Pose2d & ) const

constexprdefault

Checks equality between this Pose2d and another object.

RelativeTo()

Pose2d frc::Pose2d::RelativeTo ( const Pose2d & other ) const

constexpr

Returns the current pose relative to the given pose.

This function can often be used for trajectory tracking or pose stabilization algorithms to get the error between the reference and the current pose.

Parameters

other

The pose that is the origin of the new coordinate frame that the current pose will be converted into.

Returns

The current pose relative to the new origin pose.

RotateAround()

Pose2d frc::Pose2d::RotateAround ( const Translation2d & point, const Rotation2d & rot ) const

inlineconstexpr

Rotates the current pose around a point in 2D space.

Parameters

point	The point in 2D space to rotate around.
rot	The rotation to rotate the pose by.

Returns

The new rotated pose.

RotateBy()

Pose2d frc::Pose2d::RotateBy ( const Rotation2d & other ) const

inlineconstexpr

Rotates the pose around the origin and returns the new pose.

Parameters

other

The rotation to transform the pose by.

Returns

The rotated pose.

Rotation()

const Rotation2d & frc::Pose2d::Rotation ( ) const

inlineconstexpr

Returns the underlying rotation.

Returns

Reference to the rotational component of the pose.

ToMatrix()

Eigen::Matrix3d frc::Pose2d::ToMatrix ( ) const

inlineconstexpr

Returns an affine transformation matrix representation of this pose.

TransformBy()

Pose2d frc::Pose2d::TransformBy ( const Transform2d & other ) const

constexpr

Transforms the pose by the given transformation and returns the new pose.

See + operator for the matrix multiplication performed.

Parameters

other

The transform to transform the pose by.

Returns

The transformed pose.

Translation()

const Translation2d & frc::Pose2d::Translation ( ) const

inlineconstexpr

Returns the underlying translation.

Returns

Reference to the translational component of the pose.

X()

units::meter_t frc::Pose2d::X ( ) const

inlineconstexpr

Returns the X component of the pose's translation.

Returns

The x component of the pose's translation.

Y()

units::meter_t frc::Pose2d::Y ( ) const

inlineconstexpr

Returns the Y component of the pose's translation.

Returns

The y component of the pose's translation.

---

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

• frc/geometry/Pose2d.h