public class MecanumDrive extends RobotDriveBase
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. Each drive() function provides different inverse kinematic relations for a Mecanum drive robot.
Drive base diagram:
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Each drive() function provides different inverse kinematic relations for a Mecanum drive robot. Motor outputs for the right side are negated, so motor direction inversion by the user is usually unnecessary.
This library uses the NED axes convention (North-East-Down as external reference in the world frame): http://www.nuclearprojects.com/ins/images/axis_big.png.
The positive X axis points ahead, the positive Y axis points right, and the positive Z axis points down. Rotations follow the right-hand rule, so clockwise 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 RobotDriveBase.setDeadband(double).
RobotDrive porting guide:
In MecanumDrive, the right side speed controllers are automatically inverted, while in
RobotDrive, no speed controllers are automatically inverted.
driveCartesian(double, double, double, double) is equivalent to
RobotDrive.mecanumDrive_Cartesian(double, double, double, double)
if a deadband of 0 is used, and the ySpeed and gyroAngle values are inverted compared to
RobotDrive (eg driveCartesian(xSpeed, -ySpeed, zRotation, -gyroAngle).
drivePolar(double, double, double) is equivalent to
RobotDrive.mecanumDrive_Polar(double, double, double) if a
deadband of 0 is used.
RobotDriveBase.MotorTypekDefaultDeadband, kDefaultMaxOutput, m_deadband, m_maxOutput, m_safetyHelperDEFAULT_SAFETY_EXPIRATION| Constructor and Description |
|---|
MecanumDrive(SpeedController frontLeftMotor,
SpeedController rearLeftMotor,
SpeedController frontRightMotor,
SpeedController rearRightMotor)
Construct a MecanumDrive.
|
| Modifier and Type | Method and Description |
|---|---|
void |
driveCartesian(double ySpeed,
double xSpeed,
double zRotation)
Drive method for Mecanum platform.
|
void |
driveCartesian(double ySpeed,
double xSpeed,
double zRotation,
double gyroAngle)
Drive method for Mecanum platform.
|
void |
drivePolar(double magnitude,
double angle,
double zRotation)
Drive method for Mecanum platform.
|
java.lang.String |
getDescription() |
void |
initSendable(SendableBuilder builder)
Initializes this
Sendable object. |
void |
stopMotor() |
applyDeadband, getExpiration, isAlive, isSafetyEnabled, limit, normalize, setDeadband, setExpiration, setMaxOutput, setSafetyEnabledaddChild, free, getName, getSubsystem, setName, setName, setName, setSubsystempublic MecanumDrive(SpeedController frontLeftMotor, SpeedController rearLeftMotor, SpeedController frontRightMotor, SpeedController rearRightMotor)
If a motor needs to be inverted, do so before passing it in.
public void driveCartesian(double ySpeed, double xSpeed, double zRotation)
Angles are measured clockwise from the positive X axis. The robot's speed is independent from its angle or rotation rate.
ySpeed - The robot's speed along the Y axis [-1.0..1.0]. Right is positive.xSpeed - The robot's speed along the X axis [-1.0..1.0]. Forward is positive.zRotation - The robot's rotation rate around the Z axis [-1.0..1.0]. Clockwise is
positive.public void driveCartesian(double ySpeed, double xSpeed, double zRotation, double gyroAngle)
Angles are measured clockwise from the positive X axis. The robot's speed is independent from its angle or rotation rate.
ySpeed - The robot's speed along the Y axis [-1.0..1.0]. Right is positive.xSpeed - The robot's speed along the X axis [-1.0..1.0]. Forward is positive.zRotation - The robot's rotation rate around the Z axis [-1.0..1.0]. Clockwise is
positive.gyroAngle - The current angle reading from the gyro in degrees around the Z axis. Use
this to implement field-oriented controls.public void drivePolar(double magnitude, double angle, double zRotation)
Angles are measured counter-clockwise from straight ahead. The speed at which the robot drives (translation) is independent from its angle or rotation rate.
magnitude - The robot's speed at a given angle [-1.0..1.0]. Forward is positive.angle - The angle around the Z axis at which the robot drives in degrees [-180..180].zRotation - The robot's rotation rate around the Z axis [-1.0..1.0]. Clockwise is
positive.public void stopMotor()
stopMotor in interface MotorSafetystopMotor in class RobotDriveBasepublic java.lang.String getDescription()
getDescription in interface MotorSafetygetDescription in class RobotDriveBasepublic void initSendable(SendableBuilder builder)
SendableSendable object.builder - sendable builder