frc::Kinematics< WheelSpeeds, WheelPositions > Class Template Reference

Helper class that converts a chassis velocity (dx, dy, and dtheta components) into individual wheel speeds. More...

#include <frc/kinematics/Kinematics.h>

Public Member Functions
virtual	~Kinematics () noexcept=default
virtual ChassisSpeeds	ToChassisSpeeds (const WheelSpeeds &wheelSpeeds) const =0
	Performs forward kinematics to return the resulting chassis speed from the wheel speeds.
virtual WheelSpeeds	ToWheelSpeeds (const ChassisSpeeds &chassisSpeeds) const =0
	Performs inverse kinematics to return the wheel speeds from a desired chassis velocity.
virtual Twist2d	ToTwist2d (const WheelPositions &start, const WheelPositions &end) const =0
	Performs forward kinematics to return the resulting Twist2d from the given change in wheel positions.
virtual WheelPositions	Interpolate (const WheelPositions &start, const WheelPositions &end, double t) const =0
	Performs interpolation between two values.

Detailed Description

template<typename WheelSpeeds, typename WheelPositions>
requires std::copy_constructible<WheelPositions> && std::assignable_from<WheelPositions&, const WheelPositions&>
class frc::Kinematics< WheelSpeeds, WheelPositions >

Helper class that converts a chassis velocity (dx, dy, and dtheta components) into individual wheel speeds.

Robot code should not use this directly- Instead, use the particular type for your drivetrain (e.g., DifferentialDriveKinematics).

Inverse kinematics converts a desired chassis speed into wheel speeds whereas forward kinematics converts wheel speeds into chassis speed.

Constructor & Destructor Documentation

~Kinematics()

template<typename WheelSpeeds , typename WheelPositions >

virtual frc::Kinematics< WheelSpeeds, WheelPositions >::~Kinematics ( )

virtualdefaultnoexcept

Member Function Documentation

Interpolate()

template<typename WheelSpeeds , typename WheelPositions >

virtual WheelPositions frc::Kinematics< WheelSpeeds, WheelPositions >::Interpolate ( const WheelPositions & start, const WheelPositions & end, double t ) const

pure virtual

Performs interpolation between two values.

Parameters

start	The value to start at.
end	The value to end at.
t	How far between the two values to interpolate. This should be bounded to [0, 1].

Returns

The interpolated value.

Implemented in frc::DifferentialDriveKinematics, frc::MecanumDriveKinematics, and frc::SwerveDriveKinematics< NumModules >.

ToChassisSpeeds()

template<typename WheelSpeeds , typename WheelPositions >

virtual ChassisSpeeds frc::Kinematics< WheelSpeeds, WheelPositions >::ToChassisSpeeds ( const WheelSpeeds & wheelSpeeds ) const

pure virtual

Performs forward kinematics to return the resulting chassis speed from the wheel speeds.

This method is often used for odometry – determining the robot's position on the field using data from the real-world speed of each wheel on the robot.

Parameters

wheelSpeeds

The speeds of the wheels.

Returns

The chassis speed.

Implemented in frc::DifferentialDriveKinematics, frc::MecanumDriveKinematics, and frc::SwerveDriveKinematics< NumModules >.

ToTwist2d()

template<typename WheelSpeeds , typename WheelPositions >

virtual Twist2d frc::Kinematics< WheelSpeeds, WheelPositions >::ToTwist2d ( const WheelPositions & start, const WheelPositions & end ) const

pure virtual

Performs forward kinematics to return the resulting Twist2d from the given change in wheel positions.

This method is often used for odometry – determining the robot's position on the field using changes in the distance driven by each wheel on the robot.

Parameters

start	The starting distances driven by the wheels.
end	The ending distances driven by the wheels.

Returns

The resulting Twist2d in the robot's movement.

Implemented in frc::DifferentialDriveKinematics, frc::MecanumDriveKinematics, and frc::SwerveDriveKinematics< NumModules >.

ToWheelSpeeds()

template<typename WheelSpeeds , typename WheelPositions >

virtual WheelSpeeds frc::Kinematics< WheelSpeeds, WheelPositions >::ToWheelSpeeds ( const ChassisSpeeds & chassisSpeeds ) const

pure virtual

Performs inverse kinematics to return the wheel speeds from a desired chassis velocity.

This method is often used to convert joystick values into wheel speeds.

Parameters

chassisSpeeds

The desired chassis speed.

Returns

The wheel speeds.

Implemented in frc::DifferentialDriveKinematics, frc::MecanumDriveKinematics, and frc::SwerveDriveKinematics< NumModules >.

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

• frc/kinematics/Kinematics.h