Package xbot.common.math.kinematics

Class DeadwheelKinematics

java.lang.Object

xbot.common.math.kinematics.DeadwheelKinematics

All Implemented Interfaces:

Interpolator<DeadwheelWheelPositions>, Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

public class DeadwheelKinematics
extends Object
implements Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

Helper class that converts a deadwheel 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 Summary

Fields

Modifier and Type	Field	Description
final double	robotWidthMeters	Differential drive trackwidth.

Constructor Summary

Constructors

Constructor	Description
DeadwheelKinematics(double robotWidthMeters)	Constructs a deadwheel kinematics object.
DeadwheelKinematics(Distance robotWidth)	Constructs a deadwheel kinematics object.

Method Summary

Modifier and Type	Method	Description
DeadwheelWheelPositions	copy(DeadwheelWheelPositions positions)
void	copyInto(DeadwheelWheelPositions positions, DeadwheelWheelPositions output)
DeadwheelWheelPositions	interpolate(DeadwheelWheelPositions startValue, DeadwheelWheelPositions endValue, double t)
ChassisSpeeds	toChassisSpeeds(DeadwheelWheelSpeeds wheelSpeeds)	Returns a chassis speed from left and right component velocities using forward kinematics.
Twist2d	toTwist2d(double leftDistanceMeters, double rightDistanceMeters, double frontDistanceMeters, double rearDistanceMeters)	Performs forward kinematics to return the resulting Twist2d from the given left and right side distance deltas.
Twist2d	toTwist2d(DeadwheelWheelPositions start, DeadwheelWheelPositions end)
DeadwheelWheelSpeeds	toWheelSpeeds(ChassisSpeeds chassisSpeeds)	Returns left and right component velocities from a chassis speed using inverse kinematics.

Methods inherited from class java.lang.Object

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

Field Details

robotWidthMeters

public final double robotWidthMeters

Differential drive trackwidth.

Constructor Details

DeadwheelKinematics

public DeadwheelKinematics(double robotWidthMeters)

Constructs a deadwheel kinematics object.

Parameters:

robotWidthMeters - 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.

DeadwheelKinematics

public DeadwheelKinematics(Distance robotWidth)

Constructs a deadwheel kinematics object.

Parameters:

trackWidth - 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 Details

toChassisSpeeds

public ChassisSpeeds toChassisSpeeds(DeadwheelWheelSpeeds wheelSpeeds)

Returns a chassis speed from left and right component velocities using forward kinematics.

Specified by:

toChassisSpeeds in interface Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

Parameters:

wheelSpeeds - The left and right velocities.

Returns:

The chassis speed.

toWheelSpeeds

public DeadwheelWheelSpeeds toWheelSpeeds(ChassisSpeeds chassisSpeeds)

Returns left and right component velocities from a chassis speed using inverse kinematics.

Specified by:

toWheelSpeeds in interface Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

Parameters:

chassisSpeeds - The linear and angular (dx and dtheta) components that represent the chassis' speed.

Returns:

The left, right, front, rear velocities.

toTwist2d

public Twist2d toTwist2d(DeadwheelWheelPositions start,
 DeadwheelWheelPositions end)

Specified by:

toTwist2d in interface Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

toTwist2d

public Twist2d toTwist2d(double leftDistanceMeters,
 double rightDistanceMeters,
 double frontDistanceMeters,
 double rearDistanceMeters)

Performs forward kinematics to return the resulting Twist2d from the given left and right side distance deltas. This method is often used for odometry -- determining the robot's position on the field using changes in the distance driven by each wheel on the robot.

Parameters:

leftDistanceMeters - The distance measured by the left side encoder.

rightDistanceMeters - The distance measured by the right side encoder.

frontDistanceMeters - The distance measured by the front side encoder.

rearDistanceMeters - The distance measured by the rear side encoder.

Returns:

The resulting Twist2d.

copy

public DeadwheelWheelPositions copy(DeadwheelWheelPositions positions)

Specified by:

copy in interface Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

copyInto

public void copyInto(DeadwheelWheelPositions positions,
 DeadwheelWheelPositions output)

Specified by:

copyInto in interface Kinematics<DeadwheelWheelSpeeds,DeadwheelWheelPositions>

interpolate

public DeadwheelWheelPositions interpolate(DeadwheelWheelPositions startValue,
 DeadwheelWheelPositions endValue,
 double t)

Specified by:

interpolate in interface Interpolator<DeadwheelWheelPositions>