com.acmerobotics.roadrunner.drive

Class TankKinematics

com.acmerobotics.roadrunner.drive.TankKinematics

public class TankKinematics

Tank drive kinematic equations based upon the unicycle model. All wheel positions and velocities are given in (left, right) tuples. Robot poses are specified in a coordinate system with positive x pointing forward, positive y pointing left, and positive heading measured counter-clockwise from the x-axis.

This page gives a motivated derivation.

See Also:

This page

Field Summary

Fields

Modifier and Type	Field and Description
static TankKinematics	INSTANCE Tank drive kinematic equations based upon the unicycle model. All wheel positions and velocities are given in (left, right) tuples. Robot poses are specified in a coordinate system with positive x pointing forward, positive y pointing left, and positive heading measured counter-clockwise from the x-axis.

Method Summary

Modifier and Type	Method and Description
static java.util.List<java.lang.Double>	robotToWheelAccelerations(Pose2d robotPoseAcceleration, double trackWidth) Computes the wheel accelerations corresponding to robotPoseAcceleration given trackWidth.
static java.util.List<java.lang.Double>	robotToWheelVelocities(Pose2d robotPoseVelocity, double trackWidth) Computes the wheel velocities corresponding to robotPoseVelocity given trackWidth.
static Pose2d	wheelToRobotVelocities(java.util.List<java.lang.Double> wheelVelocities, double trackWidth) Computes the robot velocity corresponding to wheelVelocities and the given drive parameters.

Field Detail

INSTANCE

public static TankKinematics INSTANCE

Tank drive kinematic equations based upon the unicycle model. All wheel positions and velocities are given in (left, right) tuples. Robot poses are specified in a coordinate system with positive x pointing forward, positive y pointing left, and positive heading measured counter-clockwise from the x-axis.

This page gives a motivated derivation.

See Also:

This page

Method Detail

robotToWheelVelocities

public static java.util.List<java.lang.Double> robotToWheelVelocities(Pose2d robotPoseVelocity,
                                                                      double trackWidth)

Computes the wheel velocities corresponding to robotPoseVelocity given trackWidth.

Parameters:

robotPoseVelocity - velocity of the robot in its reference frame

trackWidth - lateral distance between pairs of wheels on different sides of the robot

robotToWheelAccelerations

public static java.util.List<java.lang.Double> robotToWheelAccelerations(Pose2d robotPoseAcceleration,
                                                                         double trackWidth)

Computes the wheel accelerations corresponding to robotPoseAcceleration given trackWidth.

Parameters:

robotPoseAcceleration - velocity of the robot in its reference frame

trackWidth - lateral distance between pairs of wheels on different sides of the robot

wheelToRobotVelocities

public static Pose2d wheelToRobotVelocities(java.util.List<java.lang.Double> wheelVelocities,
                                            double trackWidth)

Computes the robot velocity corresponding to wheelVelocities and the given drive parameters.

Parameters:

wheelVelocities - wheel velocities (or wheel position deltas)

trackWidth - lateral distance between pairs of wheels on different sides of the robot