ChassisVelocities

Represents the velocity of a robot chassis in its local (body) frame.

ChassisVelocities vs PoseVelocity2d

ChassisVelocities represents velocities in the robot's local frame (body frame):

• The x-axis points forward from the robot

• The y-axis points left from the robot

• Linear velocities are relative to the robot's orientation

• This is the natural frame for robot control commands

PoseVelocity2d represents velocities in the global (field) frame:

• The x and y axes are fixed to the field

• Linear velocities are relative to the field coordinate system

• This is the natural frame for trajectory planning and pose tracking

Conversion Between Frames

To convert from chassis (local) to global velocities:

val globalVel = currentPose.heading * chassisVel.linearVel

To convert from global to chassis (local) velocities:

val chassisVel = currentPose.heading.inverse() * globalVel

Example Usage

// Robot moving forward at 10 in/s, turning at 0.5 rad/s
val chassisVel = ChassisVelocities(
    linearVel = Vector2d(10.0.inchesPerSecond, 0.0.inchesPerSecond),
    angVel = 0.5.radiansPerSecond
)

// Convert to field frame
val fieldVel = PoseVelocity2d(
    linearVel = pose.heading * chassisVel.linearVel,
    angVel = chassisVel.angVel  // Angular velocity is frame-invariant
)