Class DifferentialDriveKinematics


  • public class DifferentialDriveKinematics
    extends Object
    Helper class that converts a chassis velocity (dx and dtheta components) to left and right wheel velocities for a differential drive.

    Inverse kinematics converts a desired chassis speed into left and right velocity components whereas forward kinematics converts left and right component velocities into a linear and angular chassis speed.

    • Field Detail

      • trackWidthMeters

        public final double trackWidthMeters
    • Constructor Detail

      • DifferentialDriveKinematics

        public DifferentialDriveKinematics​(double trackWidthMeters)
        Constructs a differential drive kinematics object.
        Parameters:
        trackWidthMeters - The track width of the drivetrain. Theoretically, this is the distance between the left wheels and right wheels. However, the empirical value may be larger than the physical measured value due to scrubbing effects.
    • Method Detail

      • toChassisSpeeds

        public ChassisSpeeds toChassisSpeeds​(DifferentialDriveWheelSpeeds wheelSpeeds)
        Returns a chassis speed from left and right component velocities using forward kinematics.
        Parameters:
        wheelSpeeds - The left and right velocities.
        Returns:
        The chassis speed.
      • toWheelSpeeds

        public DifferentialDriveWheelSpeeds toWheelSpeeds​(ChassisSpeeds chassisSpeeds)
        Returns left and right component velocities from a chassis speed using inverse kinematics.
        Parameters:
        chassisSpeeds - The linear and angular (dx and dtheta) components that represent the chassis' speed.
        Returns:
        The left and right velocities.