Package swervelib

Class SwerveDrive

java.lang.Object
swervelib.SwerveDrive
public class SwerveDrive extends Object
Swerve Drive class representing and controlling the swerve drive.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    edu.wpi.first.wpilibj.smartdashboard.Field2d
    field
    Field object.
    private SwerveIMU
    imu
    Swerve IMU device for sensing the heading of the robot.
    boolean
    invertOdometry
    Invert odometry readings of drive motor positions, used as a patch for debugging currently.
    final SwerveKinematics2
    kinematics
    Swerve Kinematics object utilizing second order kinematics.
    private double
    lastHeadingRadians
    The last heading set in radians.
    private int
    moduleSynchronizationCounter
    Counter to synchronize the modules relative encoder with absolute encoder when not moving.
    private SwerveIMUSimulation
    simIMU
    Simulation of the swerve drive.
    edu.wpi.first.math.Matrix<edu.wpi.first.math.numbers.N3,edu.wpi.first.math.numbers.N1>
    stateStdDevs
    Trustworthiness of the internal model of how motors should be moving Measured in expected standard deviation (meters of position and degrees of rotation)
    SwerveController
    swerveController
    Swerve controller for controlling heading of the robot.
    final SwerveDriveConfiguration
    swerveDriveConfiguration
    Swerve drive configuration.
    final edu.wpi.first.math.estimator.SwerveDrivePoseEstimator
    swerveDrivePoseEstimator
    Swerve odometry.
    private final SwerveModule[]
    swerveModules
    Swerve modules.
    edu.wpi.first.math.Matrix<edu.wpi.first.math.numbers.N3,edu.wpi.first.math.numbers.N1>
    visionMeasurementStdDevs
    Trustworthiness of the vision system Measured in expected standard deviation (meters of position and degrees of rotation)

  • Constructor Summary

    Constructors
    Constructor
    Description
    SwerveDrive(SwerveDriveConfiguration config, SwerveControllerConfiguration controllerConfig)
    Creates a new swerve drivebase subsystem.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addVisionMeasurement(edu.wpi.first.math.geometry.Pose2d robotPose, double timestamp, boolean soft, double trustWorthiness)
    Add a vision measurement to the SwerveDrivePoseEstimator and update the SwerveIMU gyro reading with the given timestamp of the vision measurement.
    void
    drive(edu.wpi.first.math.geometry.Translation2d translation, double rotation, boolean fieldRelative, boolean isOpenLoop)
    The primary method for controlling the drivebase.
    void
    drive(edu.wpi.first.math.geometry.Translation2d translation, double rotation, boolean fieldRelative, boolean isOpenLoop, boolean headingCorrection)
    The primary method for controlling the drivebase.
    edu.wpi.first.math.kinematics.ChassisSpeeds
    getFieldVelocity()
    Gets the current field-relative velocity (x, y and omega) of the robot
    edu.wpi.first.math.geometry.Rotation3d
    getGyroRotation3d()
    Gets the current gyro Rotation3d of the robot, as reported by the imu.
    edu.wpi.first.math.kinematics.SwerveModulePosition[]
    getModulePositions()
    Gets the current module positions (azimuth and wheel position (meters)).
    edu.wpi.first.math.geometry.Rotation2d
    getPitch()
    Gets the current pitch angle of the robot, as reported by the imu.
    edu.wpi.first.math.geometry.Pose2d
    getPose()
    Gets the current pose (position and rotation) of the robot, as reported by odometry.
    edu.wpi.first.math.kinematics.ChassisSpeeds
    getRobotVelocity()
    Gets the current robot-relative velocity (x, y and omega) of the robot
    edu.wpi.first.math.geometry.Rotation2d
    getRoll()
    Gets the current roll angle of the robot, as reported by the imu.
    SwerveModuleState2[]
    getStates()
    Gets the current module states (azimuth and velocity)
    edu.wpi.first.math.geometry.Pose2d[]
    getSwerveModulePoses(edu.wpi.first.math.geometry.Pose2d robotPose)
    Get the swerve module poses and on the field relative to the robot.
    edu.wpi.first.math.geometry.Rotation2d
    getYaw()
    Gets the current yaw angle of the robot, as reported by the imu.
    void
    lockPose()
    Point all modules toward the robot center, thus making the robot very difficult to move.
    void
    postTrajectory(edu.wpi.first.math.trajectory.Trajectory trajectory)
    Post the trajectory to the field
    void
    replaceSwerveModuleFeedforward(edu.wpi.first.math.controller.SimpleMotorFeedforward feedforward)
    Setup the swerve module feedforward.
    void
    resetOdometry(edu.wpi.first.math.geometry.Pose2d pose)
    Resets odometry to the given pose.
    void
    setChassisSpeeds(edu.wpi.first.math.kinematics.ChassisSpeeds chassisSpeeds)
    Set chassis speeds with closed-loop velocity control.
    void
    setModuleStates(SwerveModuleState2[] desiredStates, boolean isOpenLoop)
    Set the module states (azimuth and velocity) directly.
    void
    setMotorIdleMode(boolean brake)
    Sets the drive motors to brake/coast mode.
    void
    synchronizeModuleEncoders()
    Synchronize angle motor integrated encoders with data from absolute encoders.
    void
    updateOdometry()
    Update odometry should be run every loop.
    void
    zeroGyro()
    Resets the gyro angle to zero and resets odometry to the same position, but facing toward 0.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • kinematics

      public final SwerveKinematics2 kinematics
      Swerve Kinematics object utilizing second order kinematics.

    • swerveDriveConfiguration

      public final SwerveDriveConfiguration swerveDriveConfiguration
      Swerve drive configuration.

    • swerveDrivePoseEstimator

      public final edu.wpi.first.math.estimator.SwerveDrivePoseEstimator swerveDrivePoseEstimator
      Swerve odometry.

    • swerveModules

      private final SwerveModule[] swerveModules
      Swerve modules.

    • field

      public edu.wpi.first.wpilibj.smartdashboard.Field2d field
      Field object.

    • swerveController

      public SwerveController swerveController
      Swerve controller for controlling heading of the robot.

    • stateStdDevs

      public edu.wpi.first.math.Matrix<edu.wpi.first.math.numbers.N3,edu.wpi.first.math.numbers.N1> stateStdDevs
      Trustworthiness of the internal model of how motors should be moving Measured in expected standard deviation (meters of position and degrees of rotation)

    • visionMeasurementStdDevs

      public edu.wpi.first.math.Matrix<edu.wpi.first.math.numbers.N3,edu.wpi.first.math.numbers.N1> visionMeasurementStdDevs
      Trustworthiness of the vision system Measured in expected standard deviation (meters of position and degrees of rotation)

    • invertOdometry

      public boolean invertOdometry
      Invert odometry readings of drive motor positions, used as a patch for debugging currently.

    • imu

      private SwerveIMU imu
      Swerve IMU device for sensing the heading of the robot.

    • simIMU

      private SwerveIMUSimulation simIMU
      Simulation of the swerve drive.

    • moduleSynchronizationCounter

      private int moduleSynchronizationCounter
      Counter to synchronize the modules relative encoder with absolute encoder when not moving.

    • lastHeadingRadians

      private double lastHeadingRadians
      The last heading set in radians.

  • Constructor Details

  • Method Details

    • drive

      public void drive(edu.wpi.first.math.geometry.Translation2d translation, double rotation, boolean fieldRelative, boolean isOpenLoop)
      The primary method for controlling the drivebase. Takes a Translation2d and a rotation rate, and calculates and commands module states accordingly. Can use either open-loop or closed-loop velocity control for the wheel velocities. Also has field- and robot-relative modes, which affect how the translation vector is used. This method defaults to no heading correction.
      Parameters:
      translation - Translation2d that is the commanded linear velocity of the robot, in meters per second. In robot-relative mode, positive x is torwards the bow (front) and positive y is torwards port (left). In field-relative mode, positive x is away from the alliance wall (field North) and positive y is torwards the left wall when looking through the driver station glass (field West).
      rotation - Robot angular rate, in radians per second. CCW positive. Unaffected by field/robot relativity.
      fieldRelative - Drive mode. True for field-relative, false for robot-relative.
      isOpenLoop - Whether to use closed-loop velocity control. Set to true to disable closed-loop.

    • drive

      public void drive(edu.wpi.first.math.geometry.Translation2d translation, double rotation, boolean fieldRelative, boolean isOpenLoop, boolean headingCorrection)
      The primary method for controlling the drivebase. Takes a Translation2d and a rotation rate, and calculates and commands module states accordingly. Can use either open-loop or closed-loop velocity control for the wheel velocities. Also has field- and robot-relative modes, which affect how the translation vector is used.
      Parameters:
      translation - Translation2d that is the commanded linear velocity of the robot, in meters per second. In robot-relative mode, positive x is torwards the bow (front) and positive y is torwards port (left). In field-relative mode, positive x is away from the alliance wall (field North) and positive y is torwards the left wall when looking through the driver station glass (field West).
      rotation - Robot angular rate, in radians per second. CCW positive. Unaffected by field/robot relativity.
      fieldRelative - Drive mode. True for field-relative, false for robot-relative.
      isOpenLoop - Whether to use closed-loop velocity control. Set to true to disable closed-loop.
      headingCorrection - Whether to correct heading when driving translationally. Set to true to enable.

    • setModuleStates

      public void setModuleStates(SwerveModuleState2[] desiredStates, boolean isOpenLoop)
      Set the module states (azimuth and velocity) directly. Used primarily for auto pathing.
      Parameters:
      desiredStates - A list of SwerveModuleStates to send to the modules.
      isOpenLoop - Whether to use closed-loop velocity control. Set to true to disable closed-loop.

    • setChassisSpeeds

      public void setChassisSpeeds(edu.wpi.first.math.kinematics.ChassisSpeeds chassisSpeeds)
      Set chassis speeds with closed-loop velocity control.
      Parameters:
      chassisSpeeds - Chassis speeds to set.

    • getPose

      public edu.wpi.first.math.geometry.Pose2d getPose()
      Gets the current pose (position and rotation) of the robot, as reported by odometry.
      Returns:
      The robot's pose

    • getFieldVelocity

      public edu.wpi.first.math.kinematics.ChassisSpeeds getFieldVelocity()
      Gets the current field-relative velocity (x, y and omega) of the robot
      Returns:
      A ChassisSpeeds object of the current field-relative velocity

    • getRobotVelocity

      public edu.wpi.first.math.kinematics.ChassisSpeeds getRobotVelocity()
      Gets the current robot-relative velocity (x, y and omega) of the robot
      Returns:
      A ChassisSpeeds object of the current robot-relative velocity

    • resetOdometry

      public void resetOdometry(edu.wpi.first.math.geometry.Pose2d pose)
      Resets odometry to the given pose. Gyro angle and module positions do not need to be reset when calling this method. However, if either gyro angle or module position is reset, this must be called in order for odometry to keep working.
      Parameters:
      pose - The pose to set the odometry to

    • postTrajectory

      public void postTrajectory(edu.wpi.first.math.trajectory.Trajectory trajectory)
      Post the trajectory to the field
      Parameters:
      trajectory - the trajectory to post.

    • getStates

      public SwerveModuleState2[] getStates()
      Gets the current module states (azimuth and velocity)
      Returns:
      A list of SwerveModuleStates containing the current module states

    • getModulePositions

      public edu.wpi.first.math.kinematics.SwerveModulePosition[] getModulePositions()
      Gets the current module positions (azimuth and wheel position (meters)). Inverts the distance from each module if invertOdometry is true.
      Returns:
      A list of SwerveModulePositions containg the current module positions

    • zeroGyro

      public void zeroGyro()
      Resets the gyro angle to zero and resets odometry to the same position, but facing toward 0.

    • getYaw

      public edu.wpi.first.math.geometry.Rotation2d getYaw()
      Gets the current yaw angle of the robot, as reported by the imu. CCW positive, not wrapped.
      Returns:
      The yaw as a Rotation2d angle

    • getPitch

      public edu.wpi.first.math.geometry.Rotation2d getPitch()
      Gets the current pitch angle of the robot, as reported by the imu.
      Returns:
      The heading as a Rotation2d angle

    • getRoll

      public edu.wpi.first.math.geometry.Rotation2d getRoll()
      Gets the current roll angle of the robot, as reported by the imu.
      Returns:
      The heading as a Rotation2d angle

    • getGyroRotation3d

      public edu.wpi.first.math.geometry.Rotation3d getGyroRotation3d()
      Gets the current gyro Rotation3d of the robot, as reported by the imu.
      Returns:
      The heading as a Rotation3d angle

    • setMotorIdleMode

      public void setMotorIdleMode(boolean brake)
      Sets the drive motors to brake/coast mode.
      Parameters:
      brake - True to set motors to brake mode, false for coast.

    • lockPose

      public void lockPose()
      Point all modules toward the robot center, thus making the robot very difficult to move. Forcing the robot to keep the current pose.

    • getSwerveModulePoses

      public edu.wpi.first.math.geometry.Pose2d[] getSwerveModulePoses(edu.wpi.first.math.geometry.Pose2d robotPose)
      Get the swerve module poses and on the field relative to the robot.
      Parameters:
      robotPose - Robot pose.
      Returns:
      Swerve module poses.

    • replaceSwerveModuleFeedforward

      public void replaceSwerveModuleFeedforward(edu.wpi.first.math.controller.SimpleMotorFeedforward feedforward)
      Setup the swerve module feedforward.
      Parameters:
      feedforward - Feedforward for the drive motor on swerve modules.

    • updateOdometry

      public void updateOdometry()
      Update odometry should be run every loop. Synchronizes module absolute encoders with relative encoders periodically. In simulation mode will also post the pose of each module. Updates SmartDashboard with module encoder readings and states.

    • synchronizeModuleEncoders

      public void synchronizeModuleEncoders()
      Synchronize angle motor integrated encoders with data from absolute encoders.

    • addVisionMeasurement

      public void addVisionMeasurement(edu.wpi.first.math.geometry.Pose2d robotPose, double timestamp, boolean soft, double trustWorthiness)
      Add a vision measurement to the SwerveDrivePoseEstimator and update the SwerveIMU gyro reading with the given timestamp of the vision measurement.
      Parameters:
      robotPose - Robot Pose2d as measured by vision.
      timestamp - Timestamp the measurement was taken as time since startup, should be taken from Timer.getFPGATimestamp() or similar sources.
      soft - Add vision estimate using the SwerveDrivePoseEstimator.addVisionMeasurement(Pose2d, double) function, or hard reset odometry with the given position with SwerveDriveOdometry.resetPosition(Rotation2d, SwerveModulePosition[], Pose2d).
      trustWorthiness - Trust level of vision reading when using a soft measurement, used to multiply the standard deviation. Set to 1 for full trust.