LASGeometryUpdater.cc

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#include "Alignment/LaserAlignment/interface/LASGeometryUpdater.h"
#include "Alignment/CommonAlignment/interface/Utilities.h"

LASGeometryUpdater::LASGeometryUpdater(LASGlobalData<LASCoordinateSet>& aNominalCoordinates,
                                       LASConstants& aLasConstants) {
  nominalCoordinates = aNominalCoordinates;
  isReverseDirection = false;
  isMisalignmentFromRefGeometry = false;
  lasConstants = aLasConstants;
}

void LASGeometryUpdater::ApplyBeamKinkCorrections(LASGlobalData<LASCoordinateSet>& measuredCoordinates) const {
  for (unsigned int det = 0; det < 2; ++det) {
    for (unsigned int ring = 0; ring < 2; ++ring) {
      for (unsigned int beam = 0; beam < 8; ++beam) {
        // corrections have different sign for TEC+/-
        const double endcapSign = det == 0 ? 1. : -1.;

        // the correction is applied to the last 4 disks
        for (unsigned int disk = 5; disk < 9; ++disk) {
          measuredCoordinates.GetTECEntry(det, ring, beam, disk)
              .SetPhi(measuredCoordinates.GetTECEntry(det, ring, beam, disk).GetPhi() -
                      tan(lasConstants.GetEndcapBsKink(det, ring, beam)) / lasConstants.GetTecRadius(ring) *
                          (lasConstants.GetTecZPosition(det, disk) - endcapSign * lasConstants.GetTecBsZPosition(det)));
        }
      }
    }
  }

}

void LASGeometryUpdater::EndcapUpdate(LASEndcapAlignmentParameterSet& endcapParameters,
                                      LASGlobalData<LASCoordinateSet>& measuredCoordinates) {
  // radius of TEC ring4 laser in mm
  const double radius = 564.;

  // loop objects and its variables
  LASGlobalLoop moduleLoop;
  int det = 0, beam = 0, disk = 0;

  // update the TEC2TEC measurements
  do {
    // the measured phi value for this module
    const double currentPhi = measuredCoordinates.GetTEC2TECEntry(det, beam, disk).GetPhi();

    // the correction to phi from the endcap algorithm;
    // it is defined such that the correction is to be subtracted
    double phiCorrection = 0.;

    // plain phi component
    phiCorrection -= endcapParameters.GetDiskParameter(det, disk, 0).first;

    // phi component from x deviation
    phiCorrection += sin(nominalCoordinates.GetTEC2TECEntry(det, beam, disk).GetPhi()) / radius *
                     endcapParameters.GetDiskParameter(det, disk, 1).first;

    // phi component from y deviation
    phiCorrection -= cos(nominalCoordinates.GetTEC2TECEntry(det, beam, disk).GetPhi()) / radius *
                     endcapParameters.GetDiskParameter(det, disk, 2).first;

    measuredCoordinates.GetTEC2TECEntry(det, beam, disk).SetPhi(currentPhi - phiCorrection);

  } while (moduleLoop.TEC2TECLoop(det, beam, disk));
}

void LASGeometryUpdater::TrackerUpdate(LASEndcapAlignmentParameterSet& endcapParameters,
                                       LASBarrelAlignmentParameterSet& barrelParameters,
                                       AlignableTracker& theAlignableTracker) {
  // this constant defines the sense of *ALL* translations/rotations
  // of the alignables in the AlignableTracker object
  const int direction = (isReverseDirection || isMisalignmentFromRefGeometry) ? -1 : 1;

  // first, we access the half barrels of TIB and TOB
  const align::Alignables& theOuterHalfBarrels = theAlignableTracker.outerHalfBarrels();
  const align::Alignables& theInnerHalfBarrels = theAlignableTracker.innerHalfBarrels();

  // then the TECs and treat them also as half barrels
  const align::Alignables& theEndcaps = theAlignableTracker.endCaps();

  // re-arrange to match the structure in LASBarrelAlignmentParameterSet and simplify the loop
  // 2 (TIB+), 3 (TIB-), 4 (TOB+), 5 (TOB-)
  align::Alignables theHalfBarrels(6);
  theHalfBarrels.at(0) = theEndcaps.at(0);           // TEC+
  theHalfBarrels.at(1) = theEndcaps.at(1);           // TEC-
  theHalfBarrels.at(2) = theInnerHalfBarrels.at(1);  // TIB+
  theHalfBarrels.at(3) = theInnerHalfBarrels.at(0);  // TIB-
  theHalfBarrels.at(4) = theOuterHalfBarrels.at(1);  // TOB+
  theHalfBarrels.at(5) = theOuterHalfBarrels.at(0);  // TOB-

  // the z positions of the lower/upper-z halfbarrel_end_faces / outer_TEC_disks (in mm)
  // indices are: halfbarrel (0-5), endface(0=lowerZ,1=upperZ)
  std::vector<std::vector<double> > halfbarrelEndfaceZPositions(6, std::vector<double>(2, 0.));
  halfbarrelEndfaceZPositions.at(0).at(0) = 1322.5;
  halfbarrelEndfaceZPositions.at(0).at(1) = 2667.5;
  halfbarrelEndfaceZPositions.at(1).at(0) = -2667.5;
  halfbarrelEndfaceZPositions.at(1).at(1) = -1322.5;
  halfbarrelEndfaceZPositions.at(2).at(0) = 300.;
  halfbarrelEndfaceZPositions.at(2).at(1) = 700.;
  halfbarrelEndfaceZPositions.at(3).at(0) = -700.;
  halfbarrelEndfaceZPositions.at(3).at(1) = -300.;
  halfbarrelEndfaceZPositions.at(4).at(0) = 300.;
  halfbarrelEndfaceZPositions.at(4).at(1) = 1090.;
  halfbarrelEndfaceZPositions.at(5).at(0) = -1090.;
  halfbarrelEndfaceZPositions.at(5).at(1) = -300.;

  // z difference of half barrel end faces (= hb-length) in mm
  // do all this geometry stuff more intelligent later..
  std::vector<double> theBarrelLength(6, 0.);
  theBarrelLength.at(0) = 1345.;  // TEC
  theBarrelLength.at(1) = 1345.;
  theBarrelLength.at(2) = 400.;  // TIB
  theBarrelLength.at(3) = 400.;
  theBarrelLength.at(4) = 790.;  // TOB
  theBarrelLength.at(5) = 790.;

  // the halfbarrel centers as defined in the AlignableTracker object,
  // needed for offset corrections; code to be improved later
  std::vector<double> theHalfbarrelCenters(6, 0.);
  for (int halfbarrel = 0; halfbarrel < 6; ++halfbarrel) {
    theHalfbarrelCenters.at(halfbarrel) = theHalfBarrels.at(halfbarrel)->globalPosition().z() * 10.;  // in mm
  }

  // mm to cm conversion factor (use by division)
  const double fromMmToCm = 10.;

  // half barrel loop (no TECs -> det>1)
  for (int halfBarrel = 2; halfBarrel < 6; ++halfBarrel) {
    // A word on the factors of -1 in the below move/rotate statements:
    //
    // Since it is not possible to misalign simulated low-level objects like SiStripDigis in CMSSW,
    // LAS monte carlo digis are always ideally aligned, and misalignment is introduced
    // by displacing the reference geometry (AlignableTracker) instead which is used for stripNumber->phi conversion.
    // Hence, in case MC are used in that way, factors of -1 must be introduced
    // for rotations around x,y and translations in x,y. The variable "xyDirection" takes care of this.
    //
    // However, for rotations around z (phi) there is a complication:
    // in the analytical AlignmentTubeAlgorithm, the alignment parameter phi (z-rotation)
    // is defined such that a positive value results in a positive contribution to the residual. In the real detector,
    // the opposite is true. The resulting additional factor of -1 thus compensates for the abovementioned reference geometry effect.
    //
    // this behavior can be reversed using the "direction" factor.

    // rotation around x axis = (dy1-dy2)/L
    const align::Scalar rxLocal = (barrelParameters.GetParameter(halfBarrel, 0, 2).first -
                                   barrelParameters.GetParameter(halfBarrel, 1, 2).first) /
                                  theBarrelLength.at(halfBarrel);
    theHalfBarrels.at(halfBarrel)->rotateAroundLocalX(direction * rxLocal);

    // rotation around y axis = (dx2-dx1)/L
    const align::Scalar ryLocal = (barrelParameters.GetParameter(halfBarrel, 1, 1).first -
                                   barrelParameters.GetParameter(halfBarrel, 0, 1).first) /
                                  theBarrelLength.at(halfBarrel);
    theHalfBarrels.at(halfBarrel)->rotateAroundLocalY(direction * ryLocal);

    // average rotation around z axis = (dphi1+dphi2)/2
    const align::Scalar rzLocal = (barrelParameters.GetParameter(halfBarrel, 0, 0).first +
                                   barrelParameters.GetParameter(halfBarrel, 1, 0).first) /
                                  2.;
    theHalfBarrels.at(halfBarrel)
        ->rotateAroundLocalZ(-1. * direction * rzLocal);  // this is phi, additional -1 here, see comment above

    // now that the rotational displacements are removed, the remaining translational offsets can be corrected for.
    // for this, the effect of the rotations is subtracted from the measured endface offsets

    // @@@ the +/-/-/+ signs for the correction parameters are not yet fully understood -
    // @@@ do they flip when switching from reference-geometry-misalignment to true misalignment???
    std::vector<double> correctedEndfaceOffsetsX(2, 0.);  // lowerZ/upperZ endface
    correctedEndfaceOffsetsX.at(0) =
        barrelParameters.GetParameter(halfBarrel, 0, 1).first +
        (theHalfbarrelCenters.at(halfBarrel) - halfbarrelEndfaceZPositions.at(halfBarrel).at(0)) * ryLocal;
    correctedEndfaceOffsetsX.at(1) =
        barrelParameters.GetParameter(halfBarrel, 1, 1).first -
        (halfbarrelEndfaceZPositions.at(halfBarrel).at(1) - theHalfbarrelCenters.at(halfBarrel)) * ryLocal;

    std::vector<double> correctedEndfaceOffsetsY(2, 0.);  // lowerZ/upperZ endface
    correctedEndfaceOffsetsY.at(0) =
        barrelParameters.GetParameter(halfBarrel, 0, 2).first -
        (theHalfbarrelCenters.at(halfBarrel) - halfbarrelEndfaceZPositions.at(halfBarrel).at(0)) * rxLocal;
    correctedEndfaceOffsetsY.at(1) =
        barrelParameters.GetParameter(halfBarrel, 1, 2).first +
        (halfbarrelEndfaceZPositions.at(halfBarrel).at(1) - theHalfbarrelCenters.at(halfBarrel)) * rxLocal;

    // average x displacement = (cd1+cd2)/2
    const align::GlobalVector dxLocal(
        (correctedEndfaceOffsetsX.at(0) + correctedEndfaceOffsetsX.at(1)) / 2. / fromMmToCm, 0., 0.);
    theHalfBarrels.at(halfBarrel)->move(direction * (dxLocal));

    // average y displacement = (cd1+cd2)/s
    const align::GlobalVector dyLocal(
        0., (correctedEndfaceOffsetsY.at(0) + correctedEndfaceOffsetsY.at(1)) / 2. / fromMmToCm, 0.);
    theHalfBarrels.at(halfBarrel)->move(direction * (dyLocal));
  }

  // now fit the endcaps into that alignment tube frame. the strategy is the following:
  //
  // 1. apply the parameters from the endcap algorithm to the individual disks
  // 2. the tec as a whole is rotated and moved such that the innermost disk (1) (= halfbarrel inner endface)
  //    reaches the position determined by the barrel algorithm.
  // 3. then, the TEC is twisted and sheared until the outermost disk (9) reaches nominal position
  //    (since it has been fixed there in the alignment tube frame). this resolves any common
  //    shear and torsion within the TEC coordinate frame.

  // shortcut to the z positions of the disks' mechanical structures (TEC+/-, 9*disk)
  std::vector<std::vector<double> > wheelZPositions(2, std::vector<double>(9, 0.));
  for (int wheel = 0; wheel < 9; ++wheel) {
    wheelZPositions.at(0).at(wheel) = theEndcaps.at(0)->components().at(wheel)->globalPosition().z();
    wheelZPositions.at(1).at(wheel) = theEndcaps.at(1)->components().at(wheel)->globalPosition().z();
  }

  // we can do this for both TECs in one go;
  // only real difference is the index change in the second argument to barrelParameters::GetParameter:
  // here the disk index changes from 0(+) to 1(-), since the end faces are sorted according to z (-->side=det)

  for (int det = 0; det < 2; ++det) {
    const int& side = det;

    // step 1: apply the endcap algorithm parameters

    // factors of -1. within the move/rotate statements: see comment above.
    // difference here: in the the endcap algorithm, the alignment parameter phi (z-rotation) is defined
    // in the opposite sense compared with the AT algorithm, thus the factor of -1 applies also to phi rotations.

    for (int wheel = 0; wheel < 9; ++wheel) {
      theEndcaps.at(det)->components().at(wheel)->rotateAroundLocalZ(
          direction * endcapParameters.GetDiskParameter(det, wheel, 0).first);
      const align::GlobalVector dXY(endcapParameters.GetDiskParameter(det, wheel, 1).first / fromMmToCm,
                                    endcapParameters.GetDiskParameter(det, wheel, 2).first / fromMmToCm,
                                    0.);
      theEndcaps.at(det)->components().at(wheel)->move(direction * dXY);
    }

    // step 2: attach the innermost disk (disk 1) by rotating/moving the complete endcap

    // rotation around z of disk 1
    const align::Scalar dphi1 = barrelParameters.GetParameter(det, side, 0).first;
    theEndcaps.at(det)->rotateAroundLocalZ(-1. * direction *
                                           dphi1);  // dphi1 is from the AT algorithm, so additional sign (s.above)

    // displacement in x,y of disk 1
    const align::GlobalVector dxy1(barrelParameters.GetParameter(det, side, 1).first / fromMmToCm,
                                   barrelParameters.GetParameter(det, side, 2).first / fromMmToCm,
                                   0.);
    theEndcaps.at(det)->move(direction * dxy1);

    // determine the resulting phi, x, y of disk 9 after step 2
    // the wrong sign for TEC- is soaked up by the reducedZ in step 3
    const align::Scalar resultingPhi9 =
        barrelParameters.GetParameter(det, 1, 0).first - barrelParameters.GetParameter(det, 0, 0).first;
    const align::GlobalVector resultingXY9(
        (barrelParameters.GetParameter(det, 1, 1).first - barrelParameters.GetParameter(det, 0, 1).first) / fromMmToCm,
        (barrelParameters.GetParameter(det, 1, 2).first - barrelParameters.GetParameter(det, 0, 2).first) / fromMmToCm,
        0.);

    // step 3: twist and shear back

    // the individual rotation/movement of the wheels is a function of their z-position
    for (int wheel = 0; wheel < 9; ++wheel) {
      const double reducedZ =
          (wheelZPositions.at(det).at(wheel) - wheelZPositions.at(det).at(0)) / theBarrelLength.at(det) * fromMmToCm;
      theEndcaps.at(det)->components().at(wheel)->rotateAroundLocalZ(-1. * direction * reducedZ *
                                                                     resultingPhi9);          // twist
      theEndcaps.at(det)->components().at(wheel)->move(direction * reducedZ * resultingXY9);  // shear
    }
  }
}

void LASGeometryUpdater::SetReverseDirection(bool isSet) { isReverseDirection = isSet; }

void LASGeometryUpdater::SetMisalignmentFromRefGeometry(bool isSet) { isMisalignmentFromRefGeometry = isSet; }