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Holonomic Drivetrain ​

IMPORTANT

This page outlines how to use the mecanum drivetrain command to control your robot in TeleOp. Even though it has mecanum in the name, it works for x-drives as well.

INFO

Any holonomic drive can be controlled in one of two ways: robot centric or field centric.

Robot-centric assumes that each push of the joystick is in relation to the local position of the robot—this means that whenever the user pushes the drive stick forward, the robot will drive in the direction of its front-facing side.

Field-centric assumes that each push of the joystick is in relation to the global position of the robot—this means that whenever the user pushes the drive stick forward, the robot will move away from the driver no matter its orientation. This is done by rotating the direction of the joystick clockwise by an angle measurement equivalent to the global heading of the robot.

Usage ​

First, we need to create the motors. Let's create variables for them:

kotlin
private val frontLeftMotor = MotorEx("front_left").breakMode().reversed()
private val frontRightMotor = MotorEx("front_right").breakMode()
private val backLeftMotor = MotorEx("back_left").breakMode().reversed()
private val backRightMotor = MotorEx("back_right").breakMode()

Then, we'll create a variable for the imu. Only do this if you are using field-centric driving.

kotlin
private val imu = IMUEx("imu", Direction.UP, Direction.FORWARD).zeroed()

Lastly, in onStartButtonPressed(), we will create and schedule our command.

You can run it robot-centric:

kotlin
driverControlled = MecanumDriverControlled(
    frontLeftMotor,
    frontRightMotor,
    backLeftMotor,
    backRightMotor,
    Gamepads.gamepad1.leftStickY,
    Gamepads.gamepad1.leftStickX,
    Gamepads.gamepad1.rightStickX
)
driverControlled()

Or field-centric:

kotlin
driverControlled = MecanumDriverControlled(
    frontLeftMotor,
    frontRightMotor,
    backLeftMotor,
    backRightMotor,
    Gamepads.gamepad1.leftStickY,
    Gamepads.gamepad1.leftStickX,
    Gamepads.gamepad1.rightStickX,
    HolonomicMode.FieldCentric(imu)
)
driverControlled()

That's it! Now you are able to control your holonomic drivetrain using a gamepad.