RoadRunner Extension

This extension provides integration with the RoadRunner Library and QuickStart.

Installation

Add the following line to your build.gradle file to install the RoadRunner extension:

implementation 'dev.nextftc.extensions:roadrunner:1.0.0'

WARNING

Version 1.0.0 supports RoadRunner 1.0.1 and RoadRunner FTC 0.1.25, and is not compatible with earlier versions.

This guide also assumes you are using QuickStart for RoadRunner and its MecanumDrive class.

QuickStart Additions

To use the RoadRunner extension, make the following additions to the QuickStart code.

First, make your MecanumDrive class extend NextFTCMecanumDrive:

public class MecanumDrive extends NextFTCMecanumDrive {
    // ...
}

You will probably get an error about unimplemented members. You can copy the following implementations into your class:

    HolonomicController controller = new HolonomicController(
            PARAMS.axialGain, PARAMS.lateralGain, PARAMS.headingGain,
            PARAMS.axialVelGain, PARAMS.lateralVelGain, PARAMS.headingVelGain
    );

    @NotNull
    @Override
    public HolonomicController getController() {
        return controller;
    }

    @NotNull
    @Override
    public Pose2d getPose() {
        return localizer.getPose();
    }

    @Override
    public void setDrivePowersFF(@NotNull PoseVelocity2dDual<Time> powers) {
        MecanumKinematics.WheelVelocities<Time> wheelVels =
            kinematics.inverse(poseVelocity2dDual);
        double voltage = voltageSensor.getVoltage();
       
        final MotorFeedforward feedforward = new MotorFeedforward(
            PARAMS.kS,
            PARAMS.kV / PARAMS.inPerTick,
            PARAMS.kA / PARAMS.inPerTick
        );
        double leftFrontPower = feedforward.compute(wheelVels.leftFront) / voltage;
        double leftBackPower = feedforward.compute(wheelVels.leftBack) / voltage;
        double rightBackPower = feedforward.compute(wheelVels.rightBack) / voltage;
        double rightFrontPower = feedforward.compute(wheelVels.rightFront) / voltage;
        mecanumCommandWriter.write(new MecanumCommandMessage(
            voltage, leftFrontPower, leftBackPower, rightBackPower, rightFrontPower
        ));

        leftFront.setPower(feedforward.compute(wheelVels.leftFront) / voltage);
        leftBack.setPower(feedforward.compute(wheelVels.leftBack) / voltage);
        rightBack.setPower(feedforward.compute(wheelVels.rightBack) / voltage);
        rightFront.setPower(feedforward.compute(wheelVels.rightFront) / voltage);
    }

    @Override
    @NotNull
    public TrajectoryCommandBuilder commandBuilder(@NotNull Pose2d beginPose) {
        return new TrajectoryCommandBuilder(
                turn -> new Turn(this, turn),
                traj -> new FollowTrajectory(this, traj),
                new TrajectoryBuilderParams(
                        1e-6,
                        new ProfileParams(
                                0.25, 0.1, 1e-2
                        )
                ),
                beginPose, 0.0,
                defaultTurnConstraints,
                defaultVelConstraint, defaultAccelConstraint
        );
    }

Android Studio will probably suggest the necessary imports.

There is an example MecanumDrive class in the NextFTC branch of my RoadRunner QuickStart fork. Note that this is just an example and may not be updated to the latest version of RoadRunner or NextFTC.