Package edu.wpi.first.wpilibj.drive

Class KilloughDrive

java.lang.Object
edu.wpi.first.wpilibj.MotorSafety
edu.wpi.first.wpilibj.drive.RobotDriveBase
edu.wpi.first.wpilibj.drive.KilloughDrive
All Implemented Interfaces:
Sendable, AutoCloseable
public class KilloughDrive
extends RobotDriveBase
implements Sendable, AutoCloseable
A class for driving Killough drive platforms.

Killough drives are triangular with one omni wheel on each corner.

Drive base diagram: 

  /_____\
 / \   / \
    \ /
    ---

Each drive() function provides different inverse kinematic relations for a Killough drive. The default wheel vectors are parallel to their respective opposite sides, but can be overridden. See the constructor for more information.

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.

  • Field Details

  • Constructor Details

    • KilloughDrive

      public KilloughDrive​(SpeedController leftMotor, SpeedController rightMotor, SpeedController backMotor)
      Construct a Killough drive with the given motors and default motor angles.

      The default motor angles make the wheels on each corner parallel to their respective opposite sides.

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

      Parameters:
      leftMotor - The motor on the left corner.
      rightMotor - The motor on the right corner.
      backMotor - The motor on the back corner.

    • KilloughDrive

      public KilloughDrive​(SpeedController leftMotor, SpeedController rightMotor, SpeedController backMotor, double leftMotorAngle, double rightMotorAngle, double backMotorAngle)
      Construct a Killough drive with the given motors.

      Angles are measured in degrees clockwise from the positive X axis.

      Parameters:
      leftMotor - The motor on the left corner.
      rightMotor - The motor on the right corner.
      backMotor - The motor on the back corner.
      leftMotorAngle - The angle of the left wheel's forward direction of travel.
      rightMotorAngle - The angle of the right wheel's forward direction of travel.
      backMotorAngle - The angle of the back wheel's forward direction of travel.

  • Method Details

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable

    • driveCartesian

      public void driveCartesian​(double ySpeed, double xSpeed, double zRotation)
      Drive method for Killough platform.

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

      Parameters:
      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.

    • driveCartesian

      public void driveCartesian​(double ySpeed, double xSpeed, double zRotation, double gyroAngle)
      Drive method for Killough platform.

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

      Parameters:
      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.

    • drivePolar

      public void drivePolar​(double magnitude, double angle, double zRotation)
      Drive method for Killough platform.

      Angles are measured counter-clockwise from straight ahead. The speed at which the robot drives (translation) is independent from its angle or rotation rate.

      Parameters:
      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.

    • driveCartesianIK

      public KilloughDrive.WheelSpeeds driveCartesianIK​(double ySpeed, double xSpeed, double zRotation, double gyroAngle)
      Cartesian inverse kinematics for Killough platform.

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

      Parameters:
      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.
      Returns:
      Wheel speeds.

    • stopMotor

      public void stopMotor()
      Specified by:
      stopMotor in class RobotDriveBase

    • getDescription

      public String getDescription()
      Specified by:
      getDescription in class RobotDriveBase

    • initSendable

      public void initSendable​(SendableBuilder builder)
      Description copied from interface: Sendable
      Initializes this Sendable object.
      Specified by:
      initSendable in interface Sendable
      Parameters:
      builder - sendable builder