public void compute(
      FrameVector output,
      FrameOrientation desiredOrientation,
      FrameVector desiredAngularVelocity,
      FrameVector currentAngularVelocity,
      FrameVector feedForward) {
    computeProportionalTerm(desiredOrientation);
    if (currentAngularVelocity != null)
      computeDerivativeTerm(desiredAngularVelocity, currentAngularVelocity);
    computeIntegralTerm();

    output.setToZero(proportionalTerm.getReferenceFrame());
    output.add(proportionalTerm);
    output.add(derivativeTerm);
    output.add(integralTerm);

    // Limit the max acceleration of the feedback, but not of the feedforward...
    // JEP changed 150430 based on Atlas hitting limit stops.
    double feedbackAngularActionMagnitude = output.length();
    double maximumAction = gains.getMaximumFeedback();
    if (feedbackAngularActionMagnitude > maximumAction) {
      output.scale(maximumAction / feedbackAngularActionMagnitude);
    }

    feedbackAngularAction.set(output);
    rateLimitedFeedbackAngularAction.update();
    rateLimitedFeedbackAngularAction.getFrameTuple(output);

    feedForward.changeFrame(bodyFrame);
    output.add(feedForward);
  }
  @ContinuousIntegrationTest(estimatedDuration = 0.0)
  @Test(timeout = 30000)
  public void testSingleRigidBodyRotation() {
    Random random = new Random(1766L);

    RigidBody elevator = new RigidBody("elevator", world);
    Vector3d jointAxis = RandomTools.generateRandomVector(random);
    jointAxis.normalize();
    RigidBodyTransform transformToParent = new RigidBodyTransform();
    transformToParent.setIdentity();
    RevoluteJoint joint =
        ScrewTools.addRevoluteJoint("joint", elevator, transformToParent, jointAxis);
    RigidBody body =
        ScrewTools.addRigidBody(
            "body",
            joint,
            RandomTools.generateRandomDiagonalMatrix3d(random),
            random.nextDouble(),
            new Vector3d());

    joint.setQ(random.nextDouble());
    joint.setQd(random.nextDouble());

    Momentum momentum = computeMomentum(elevator, world);

    momentum.changeFrame(world);
    FrameVector linearMomentum =
        new FrameVector(momentum.getExpressedInFrame(), momentum.getLinearPartCopy());
    FrameVector angularMomentum =
        new FrameVector(momentum.getExpressedInFrame(), momentum.getAngularPartCopy());

    FrameVector linearMomentumCheck = new FrameVector(world);
    Matrix3d inertia = body.getInertia().getMassMomentOfInertiaPartCopy();
    Vector3d angularMomentumCheckVector = new Vector3d(jointAxis);
    angularMomentumCheckVector.scale(joint.getQd());
    inertia.transform(angularMomentumCheckVector);
    FrameVector angularMomentumCheck =
        new FrameVector(body.getInertia().getExpressedInFrame(), angularMomentumCheckVector);
    angularMomentumCheck.changeFrame(world);

    double epsilon = 1e-9;
    JUnitTools.assertTuple3dEquals(
        linearMomentumCheck.getVector(), linearMomentum.getVector(), epsilon);
    JUnitTools.assertTuple3dEquals(
        angularMomentumCheck.getVector(), angularMomentum.getVector(), epsilon);
    assertTrue(angularMomentum.length() > epsilon);
  }
  private void computeDerivativeTerm(
      FrameVector desiredAngularVelocity, FrameVector currentAngularVelocity) {
    desiredAngularVelocity.changeFrame(bodyFrame);
    currentAngularVelocity.changeFrame(bodyFrame);

    derivativeTerm.sub(desiredAngularVelocity, currentAngularVelocity);

    // Limit the maximum velocity error considered for control action
    double maximumVelocityError = gains.getMaximumDerivativeError();
    double velocityErrorMagnitude = derivativeTerm.length();
    if (velocityErrorMagnitude > maximumVelocityError) {
      derivativeTerm.scale(maximumVelocityError / velocityErrorMagnitude);
    }

    velocityError.set(derivativeTerm);
    derivativeGainMatrix.transform(derivativeTerm.getVector());
  }