A class for driving Mecanum drive platforms. More...

#include <wpi/drive/MecanumDrive.hpp>

Inheritance diagram for wpi::MecanumDrive:

Classes
struct	WheelVelocities
	Wheel velocities for a mecanum drive. More...

Public Member Functions
WPI_IGNORE_DEPRECATED	MecanumDrive (MotorController &frontLeftMotor, MotorController &rearLeftMotor, MotorController &frontRightMotor, MotorController &rearRightMotor)
	Construct a MecanumDrive.
WPI_UNIGNORE_DEPRECATED	MecanumDrive (std::function< void(double)> frontLeftMotor, std::function< void(double)> rearLeftMotor, std::function< void(double)> frontRightMotor, std::function< void(double)> rearRightMotor)
	Construct a MecanumDrive.
	~MecanumDrive () override=default
	MecanumDrive (MecanumDrive &&)=default
MecanumDrive &	operator= (MecanumDrive &&)=default
void	DriveCartesian (double xVelocity, double yVelocity, double zRotation, wpi::math::Rotation2d gyroAngle=0_rad)
	Drive method for Mecanum platform.
void	DrivePolar (double magnitude, wpi::math::Rotation2d angle, double zRotation)
	Drive method for Mecanum platform.
void	StopMotor () override
	Called to stop the motor when the timeout expires.
std::string	GetDescription () const override
	Returns a description to print when an error occurs.
void	InitSendable (wpi::util::SendableBuilder &builder) override
	Initializes this Sendable object.
Public Member Functions inherited from wpi::RobotDriveBase
	RobotDriveBase ()
	~RobotDriveBase () override=default
	RobotDriveBase (RobotDriveBase &&)=default
RobotDriveBase &	operator= (RobotDriveBase &&)=default
void	SetDeadband (double deadband)
	Sets the deadband applied to the drive inputs (e.g., joystick values).
void	SetMaxOutput (double maxOutput)
	Configure the scaling factor for using RobotDrive with motor controllers in a mode other than PercentVbus or to limit the maximum output.
void	FeedWatchdog ()
	Feed the motor safety object.
Public Member Functions inherited from wpi::MotorSafety
	MotorSafety ()
virtual	~MotorSafety ()
	MotorSafety (MotorSafety &&rhs)
MotorSafety &	operator= (MotorSafety &&rhs)
void	Feed ()
	Feed the motor safety object.
void	SetExpiration (wpi::units::second_t expirationTime)
	Set the expiration time for the corresponding motor safety object.
wpi::units::second_t	GetExpiration () const
	Retrieve the timeout value for the corresponding motor safety object.
bool	IsAlive () const
	Determine if the motor is still operating or has timed out.
void	SetSafetyEnabled (bool enabled)
	Enable/disable motor safety for this device.
bool	IsSafetyEnabled () const
	Return the state of the motor safety enabled flag.
void	Check ()
	Check if this motor has exceeded its timeout.
Public Member Functions inherited from wpi::util::Sendable
virtual constexpr	~Sendable ()=default
Public Member Functions inherited from wpi::util::SendableHelper< MecanumDrive >
constexpr	SendableHelper (const SendableHelper &rhs)=default
constexpr SendableHelper &	operator= (const SendableHelper &rhs)=default

Static Public Member Functions
static WheelVelocities	DriveCartesianIK (double xVelocity, double yVelocity, double zRotation, wpi::math::Rotation2d gyroAngle=0_rad)
	Cartesian inverse kinematics for Mecanum platform.
Static Public Member Functions inherited from wpi::MotorSafety
static void	CheckMotors ()
	Check the motors to see if any have timed out.

Additional Inherited Members
Public Types inherited from wpi::RobotDriveBase
enum	MotorType { kFrontLeft = 0 , kFrontRight = 1 , kRearLeft = 2 , kRearRight = 3 , kLeft = 0 , kRight = 1 , kBack = 2 }
	The location of a motor on the robot for the purpose of driving. More...
Protected Member Functions inherited from wpi::util::SendableHelper< MecanumDrive >
constexpr	~SendableHelper ()
Static Protected Member Functions inherited from wpi::RobotDriveBase
static void	Desaturate (std::span< double > wheelVelocities)
	Renormalize all wheel velocities if the magnitude of any wheel is greater than 1.0.
Protected Attributes inherited from wpi::RobotDriveBase
double	m_deadband = kDefaultDeadband
	Input deadband.
double	m_maxOutput = kDefaultMaxOutput
	Maximum output.
Static Protected Attributes inherited from wpi::RobotDriveBase
static constexpr double	kDefaultDeadband = 0.02
	Default input deadband.
static constexpr double	kDefaultMaxOutput = 1.0
	Default maximum output.

Detailed Description

A class for driving Mecanum drive platforms.

Mecanum drives are rectangular with one wheel on each corner. Each wheel has rollers toed in 45 degrees toward the front or back. When looking at the wheels from the top, the roller axles should form an X across the robot.

Drive base diagram:

\_______/
\ |   | /
  |   |
/_|___|_\
/       \

Each Drive() function provides different inverse kinematic relations for a Mecanum drive robot.

This library uses the NWU axes convention (North-West-Up as external reference in the world frame). The positive X axis points ahead, the positive Y axis points to the left, and the positive Z axis points up. Rotations follow the right-hand rule, so counterclockwise rotation around the Z axis is positive.

Inputs smaller then 0.02 will be set to 0, and larger values will be scaled so that the full range is still used. This deadband value can be changed with SetDeadband().

MotorSafety is enabled by default. The DriveCartesian or DrivePolar methods should be called periodically to avoid Motor Safety timeouts.

Constructor & Destructor Documentation

◆ MecanumDrive() [1/3]

WPI_IGNORE_DEPRECATED wpi::MecanumDrive::MecanumDrive	(	MotorController &	frontLeftMotor,
		MotorController &	rearLeftMotor,
		MotorController &	frontRightMotor,
		MotorController &	rearRightMotor )

Construct a MecanumDrive.

If a motor needs to be inverted, do so before passing it in.

Parameters

frontLeftMotor	Front-left motor.
rearLeftMotor	Rear-left motor.
frontRightMotor	Front-right motor.
rearRightMotor	Rear-right motor.

◆ MecanumDrive() [2/3]

WPI_UNIGNORE_DEPRECATED wpi::MecanumDrive::MecanumDrive	(	std::function< void(double)>	frontLeftMotor,
		std::function< void(double)>	rearLeftMotor,
		std::function< void(double)>	frontRightMotor,
		std::function< void(double)>	rearRightMotor )

Construct a MecanumDrive.

If a motor needs to be inverted, do so before passing it in.

Parameters

frontLeftMotor	Front-left motor setter.
rearLeftMotor	Rear-left motor setter.
frontRightMotor	Front-right motor setter.
rearRightMotor	Rear-right motor setter.

◆ ~MecanumDrive()

wpi::MecanumDrive::~MecanumDrive ( )

overridedefault

◆ MecanumDrive() [3/3]

wpi::MecanumDrive::MecanumDrive ( MecanumDrive && )

default

Member Function Documentation

◆ DriveCartesian()

void wpi::MecanumDrive::DriveCartesian	(	double	xVelocity,
		double	yVelocity,
		double	zRotation,
		wpi::math::Rotation2d	gyroAngle = 0_rad )

Drive method for Mecanum platform.

Angles are measured counterclockwise from the positive X axis. The robot's velocity is independent from its angle or rotation rate.

Parameters

xVelocity	The robot's velocity along the X axis [-1.0..1.0]. Forward is positive.
yVelocity	The robot's velocity along the Y axis [-1.0..1.0]. Left is positive.
zRotation	The robot's rotation rate around the Z axis [-1.0..1.0]. Counterclockwise is positive.
gyroAngle	The gyro heading around the Z axis. Use this to implement field-oriented controls.

◆ DriveCartesianIK()

WheelVelocities wpi::MecanumDrive::DriveCartesianIK	(	double	xVelocity,
		double	yVelocity,
		double	zRotation,
		wpi::math::Rotation2d	gyroAngle = 0_rad )

static

Cartesian inverse kinematics for Mecanum platform.

Angles are measured counterclockwise from the positive X axis. The robot's velocity is independent from its angle or rotation rate.

Parameters

xVelocity	The robot's velocity along the X axis [-1.0..1.0]. Forward is positive.
yVelocity	The robot's velocity along the Y axis [-1.0..1.0]. Left is positive.
zRotation	The robot's rotation rate around the Z axis [-1.0..1.0]. Counterclockwise is positive.
gyroAngle	The gyro heading around the Z axis. Use this to implement field-oriented controls.

Returns: Wheel velocities [-1.0..1.0].

◆ DrivePolar()

void wpi::MecanumDrive::DrivePolar	(	double	magnitude,
		wpi::math::Rotation2d	angle,
		double	zRotation )

Drive method for Mecanum platform.

Angles are measured counterclockwise from the positive X axis. The robot's velocity is independent from its angle or rotation rate.

Parameters

magnitude	The robot's velocity at a given angle [-1.0..1.0]. Forward is positive.
angle	The angle around the Z axis at which the robot drives.
zRotation	The robot's rotation rate around the Z axis [-1.0..1.0]. Counterclockwise is positive.

◆ GetDescription()

std::string wpi::MecanumDrive::GetDescription ( ) const

overridevirtual

Returns a description to print when an error occurs.

Returns: Description to print when an error occurs.

Implements wpi::RobotDriveBase.

◆ InitSendable()

void wpi::MecanumDrive::InitSendable ( wpi::util::SendableBuilder & builder )

overridevirtual

Initializes this Sendable object.

Parameters

builder sendable builder

Implements wpi::util::Sendable.

◆ operator=()

MecanumDrive & wpi::MecanumDrive::operator= ( MecanumDrive && )

default

◆ StopMotor()

void wpi::MecanumDrive::StopMotor ( )

overridevirtual

Called to stop the motor when the timeout expires.

Implements wpi::RobotDriveBase.

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

wpi/drive/MecanumDrive.hpp

Classes

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MecanumDrive() [1/3]

◆ MecanumDrive() [2/3]

◆ ~MecanumDrive()

◆ MecanumDrive() [3/3]

Member Function Documentation

◆ DriveCartesian()

◆ DriveCartesianIK()

◆ DrivePolar()

◆ GetDescription()

◆ InitSendable()

◆ operator=()

◆ StopMotor()