Three Wheel

Automatic Tuning

The Three Wheel AutoTuner can automatically determine the values needed for your ThreeWheelConfig, including encoder directions, encoder resolutions, pod offsets, and the turn multiplier.

During the procedure, you will enter which motor encoder ports your odometry pods are plugged into, then move the robot by hand when AutoTune asks you to.

The tuner determines:

• forwardTicksToInches
• strafeTicksToInches
• turnTicksToRadians
• leftEncoderDirection
• rightEncoderDirection
• strafeEncoderDirection
• leftPodY
• rightPodY
• strafePodX

Add the Tuner

Inside your Tuning class, add:

@Tuner
public static Procedure threeWheelTuner() {
    return new ThreeWheelTuner();
}

Make sure ThreeWheelTuner is imported:

import org.firstinspires.ftc.teamcode.pedro.procedures.ThreeWheelTuner;

Build and send the updated code to the Robot Controller.

Open AutoTune

While connected to the Robot Controller, open the following address in your browser: http://192.168.43.1:10158

Select Three Wheel Tuner.

Encoder Setup

Enter the HardwareMap name of the motor port that each odometry encoder is plugged into.

For example, if your left pod encoder is plugged into the encoder port for a motor named lf in your Robot Configuration, enter:

lf

in the Left Encoder Motor Name field.

Do the same for the right and strafe pods.

The default values are:

Left Encoder Motor Name:   lf
Right Encoder Motor Name:  rr
Strafe Encoder Motor Name: lr

Change these names to match your robot, then press Submit.

Encoder Resolution Setup

Next, enter the distance in inches that you want to move the robot during the encoder resolution tests.

The default is:

48

For example, if you leave the value at 48, you must move the robot exactly 48 inches during each resolution test.

Enter the distance you want to use, then press Submit.

Left Encoder Resolution and Direction

Press Continue, then start the tuning OpMode.

Push the robot straight forward by the exact distance entered during setup.

For example, if the distance is 48 inches, push the robot forward exactly 48 inches.

While the test is running, telemetry displays information including:

• Left, right, and strafe SDK encoder ticks
• Corrected encoder ticks
• Localizer X and Y
• Total heading
• The selected pod
• The measured movement

After the robot has moved the full distance, stop moving it and press Stop.

The tuner will determine the encoder resolution and direction for the left parallel pod.

Right Encoder Resolution and Direction

Press Continue, then start the tuning OpMode.

Push the robot straight forward by the same exact distance.

After the robot has moved the full distance, stop moving it and press Stop.

The tuner will determine the encoder resolution and direction for the right parallel pod.

The final forwardTicksToInches value is calculated using both parallel pod measurements.

Strafe Encoder Resolution and Direction

Press Continue, then start the tuning OpMode.

Push the robot straight to the left by the exact distance entered during setup.

After the robot has moved the full distance, stop moving it and press Stop.

The tuner determines:

c.strafeTicksToInches.set(...);
c.strafeEncoderDirection.set(...);

Left Pod Offset Identification

Press Continue, then start the tuning OpMode.

Rotate the robot exactly 180 degrees counterclockwise about the robot's center of rotation.

Keep the center of the robot in the same position as closely as possible.

After completing the rotation, stop moving and press Stop.

The tuner uses the measured parallel pod travel to calculate leftPodY.

Right Pod Offset Identification

Press Continue, then start the tuning OpMode.

Again, rotate the robot exactly 180 degrees counterclockwise about the robot's center.

After completing the rotation, stop moving and press Stop.

The tuner uses the measured parallel pod travel to calculate rightPodY.

Turn Multiplier Identification

Press Continue, then start the tuning OpMode.

Rotate the robot exactly 360 degrees counterclockwise.

Use a fixed reference point so the full rotation can be measured accurately.

After completing the rotation, stop moving and press Stop.

The tuner calculates:

c.turnTicksToRadians.set(...);

The tuner also uses the offset-stage measurements together with the turn measurement to finish calculating:

c.strafePodX.set(...);

Applying the Results

Once the tuner is complete, open the Java tab.

AutoTune will generate a complete ThreeWheelConfig using the values determined during the tuning procedure.

The generated configuration includes:

• Left encoder name
• Right encoder name
• Strafe encoder name
• Left pod Y offset
• Right pod Y offset
• Strafe pod X offset
• Forward ticks to inches
• Strafe ticks to inches
• Turn ticks to radians
• Left encoder direction
• Right encoder direction
• Strafe encoder direction

The generated encoder names will match the HardwareMap names entered during Encoder Setup.

Copy the generated configuration into the ThreeWheelConfig in your Constants.java file.

Manual Offset Tuning

Offsets can also be found manually using the diagram below. Offsets are in inches.

Set your odometry pod offsets to define where they are relative to your robot's center of rotation.

Testing the Localizer

Once you have completed the tuning steps, test your localizer using the localization test.

Move the robot forward. X should increase.

Move the robot left. Y should increase.

Rotate the robot counterclockwise. Heading should increase.

If the reported motion does not match the physical robot motion, rerun the tuner and verify:

• The encoder mapping
• The requested push distances
• The counterclockwise rotations
• The generated encoder directions

Congratulations on successfully tuning your Three Wheel localizer!

Troubleshooting

If you have any problems, see the troubleshooting page.