[wpimath] Replace Speeds with Velocities (#8479)

I left "free speed" alone since that's the technical term for it. In
general, velocity is a vector quantity, and speed is a magnitude (i.e.,
a strictly positive value).

This PR also replaces the speed verbiage in MotorController with duty
cycle.

Fixes #8423.

robotpyExamples/HatchbotTraditional/commands/complexauto.py

@@ -24,12 +24,12 @@ class ComplexAuto(commands2.SequentialCommandGroup):
         super().__init__(
             # Drive forward the specified distance
             DriveDistance(
-                constants.kAutoDriveDistanceInches, constants.kAutoDriveSpeed, drive
+                constants.kAutoDriveDistanceInches, constants.kAutoDriveVelocity, drive
             ),
             # Release the hatch
             ReleaseHatch(hatch),
             # Drive backward the specified distance
             DriveDistance(
-                constants.kAutoBackupDistanceInches, -constants.kAutoDriveSpeed, drive
+                constants.kAutoBackupDistanceInches, -constants.kAutoDriveVelocity, drive
             ),
         )

robotpyExamples/HatchbotTraditional/commands/drivedistance.py

@@ -10,18 +10,18 @@ from subsystems.drivesubsystem import DriveSubsystem
 
 
 class DriveDistance(commands2.Command):
-    def __init__(self, inches: float, speed: float, drive: DriveSubsystem) -> None:
+    def __init__(self, inches: float, velocity: float, drive: DriveSubsystem) -> None:
         self.distance = inches
-        self.speed = speed
+        self.velocity = velocity
         self.drive = drive
         self.addRequirements(drive)
 
     def initialize(self) -> None:
         self.drive.resetEncoders()
-        self.drive.arcadeDrive(self.speed, 0)
+        self.drive.arcadeDrive(self.velocity, 0)
 
     def execute(self) -> None:
-        self.drive.arcadeDrive(self.speed, 0)
+        self.drive.arcadeDrive(self.velocity, 0)
 
     def end(self, interrupted: bool) -> None:
         self.drive.arcadeDrive(0, 0)

robotpyExamples/HatchbotTraditional/commands/halvedrivevelocity.py

@@ -9,7 +9,7 @@ import commands2
 from subsystems.drivesubsystem import DriveSubsystem
 
 
-class HalveDriveSpeed(commands2.Command):
+class HalveDriveVelocity(commands2.Command):
     def __init__(self, drive: DriveSubsystem) -> None:
         self.drive = drive
 

robotpyExamples/HatchbotTraditional/constants.py

@@ -37,7 +37,7 @@ kHatchSolenoidPorts = (0, 1)
 # Autonomous
 kAutoDriveDistanceInches = 60
 kAutoBackupDistanceInches = 20
-kAutoDriveSpeed = 0.5
+kAutoDriveVelocity = 0.5
 
 # Operator Interface
 kDriverControllerPort = 0

robotpyExamples/HatchbotTraditional/robotcontainer.py

@@ -15,7 +15,7 @@ from commands.complexauto import ComplexAuto
 from commands.drivedistance import DriveDistance
 from commands.defaultdrive import DefaultDrive
 from commands.grabhatch import GrabHatch
-from commands.halvedrivespeed import HalveDriveSpeed
+from commands.halvedrivevelocity import HalveDriveVelocity
 from commands.releasehatch import ReleaseHatch
 
 from subsystems.drivesubsystem import DriveSubsystem
@@ -43,7 +43,7 @@ class RobotContainer:
 
         # A simple auto routine that drives forward a specified distance, and then stops.
         self.simpleAuto = DriveDistance(
-            constants.kAutoDriveDistanceInches, constants.kAutoDriveSpeed, self.drive
+            constants.kAutoDriveDistanceInches, constants.kAutoDriveVelocity, self.drive
         )
 
         # A complex auto routine that drives forward, drops a hatch, and then drives backward.
@@ -86,7 +86,7 @@ class RobotContainer:
         )
 
         commands2.button.JoystickButton(self.driverController, 3).whileTrue(
-            HalveDriveSpeed(self.drive)
+            HalveDriveVelocity(self.drive)
         )
 
     def getAutonomousCommand(self) -> commands2.Command:

robotpyExamples/HatchbotTraditional/subsystems/drivesubsystem.py

@@ -17,7 +17,7 @@ class DriveSubsystem(commands2.Subsystem):
         self.right1 = wpilib.PWMVictorSPX(constants.kRightMotor1Port)
         self.right2 = wpilib.PWMVictorSPX(constants.kRightMotor2Port)
 
-        # We need to invert one side of the drivetrain so that positive speeds
+        # We need to invert one side of the drivetrain so that positive velocities
         # result in both sides moving forward. Depending on how your robot's
         # drivetrain is constructed, you might have to invert the left side instead.
         self.right1.setInverted(True)