Package edu.wpi.first.math.controller

Class HolonomicDriveController

java.lang.Object

edu.wpi.first.math.controller.HolonomicDriveController

public class HolonomicDriveController
extends Object

This holonomic drive controller can be used to follow trajectories using a holonomic drivetrain (i.e. swerve or mecanum). Holonomic trajectory following is a much simpler problem to solve compared to skid-steer style drivetrains because it is possible to individually control forward, sideways, and angular velocity.

The holonomic drive controller takes in one PID controller for each direction, forward and sideways, and one profiled PID controller for the angular direction. Because the heading dynamics are decoupled from translations, users can specify a custom heading that the drivetrain should point toward. This heading reference is profiled for smoothness.

Constructor Summary

Constructors

Constructor	Description
HolonomicDriveController(PIDController xController, PIDController yController, ProfiledPIDController thetaController)	Constructs a holonomic drive controller.

Method Summary

Modifier and Type	Method	Description
boolean	atReference()	Returns true if the pose error is within tolerance of the reference.
ChassisSpeeds	calculate(Pose2d currentPose, Pose2d trajectoryPose, double desiredLinearVelocityMetersPerSecond, Rotation2d desiredHeading)	Returns the next output of the holonomic drive controller.
ChassisSpeeds	calculate(Pose2d currentPose, Trajectory.State desiredState, Rotation2d desiredHeading)	Returns the next output of the holonomic drive controller.
void	setEnabled(boolean enabled)	Enables and disables the controller for troubleshooting problems.
void	setTolerance(Pose2d tolerance)	Sets the pose error which is considered tolerance for use with atReference().

Methods inherited from class java.lang.Object

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

Constructor Details

HolonomicDriveController

public HolonomicDriveController(PIDController xController, PIDController yController, ProfiledPIDController thetaController)

Constructs a holonomic drive controller.

Parameters:

xController - A PID Controller to respond to error in the field-relative x direction.

yController - A PID Controller to respond to error in the field-relative y direction.

thetaController - A profiled PID controller to respond to error in angle.

Method Details

atReference

public boolean atReference()

Returns true if the pose error is within tolerance of the reference.

Returns:

True if the pose error is within tolerance of the reference.

setTolerance

public void setTolerance(Pose2d tolerance)

Sets the pose error which is considered tolerance for use with atReference().

Parameters:

tolerance - The pose error which is tolerable.

calculate

public ChassisSpeeds calculate(Pose2d currentPose, Pose2d trajectoryPose, double desiredLinearVelocityMetersPerSecond, Rotation2d desiredHeading)

Returns the next output of the holonomic drive controller.

Parameters:

currentPose - The current pose, as measured by odometry or pose estimator.

trajectoryPose - The desired trajectory pose, as sampled for the current timestep.

desiredLinearVelocityMetersPerSecond - The desired linear velocity.

desiredHeading - The desired heading.

Returns:

The next output of the holonomic drive controller.

calculate

public ChassisSpeeds calculate(Pose2d currentPose, Trajectory.State desiredState, Rotation2d desiredHeading)

Returns the next output of the holonomic drive controller.

Parameters:

currentPose - The current pose, as measured by odometry or pose estimator.

desiredState - The desired trajectory pose, as sampled for the current timestep.

desiredHeading - The desired heading.

Returns:

The next output of the holonomic drive controller.

setEnabled

public void setEnabled(boolean enabled)

Enables and disables the controller for troubleshooting problems. When calculate() is called on a disabled controller, only feedforward values are returned.

Parameters:

enabled - If the controller is enabled or not.