Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH [email protected] June 9, 2009 FAC,...

17
Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH [email protected] .edu June 9, 2009 FAC, June 2009
  • date post

    21-Dec-2015
  • Category

    Documents

  • view

    232
  • download

    6

Transcript of Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH [email protected] June 9, 2009 FAC,...

Page 1: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

Undulator Motion Controls

Jim WelchJune 9, 2009

J. [email protected]

du

June 9, 2009FAC, June 2009

Page 2: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 2

Outline

• Basics

• Performance

• calibration

•motion

• Stability

Page 3: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 3

Degrees of Freedom

• Girder: x,y, (2X) and roll, control Q, BPM, BFW and undulator transverse positions.

• Undulator: girder motion plus 85 mm of horizontal translation

• 33x6 total degrees of freedom for mechanical motion

-5 to 80 mm

+/- 1 mm

UndulatorUndulator BPMBPMQQBFWBFW

Page 4: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 4

Linear Potentiometers

• Six linear potentiometers provide indepenent on-line measurement of girder motion with about 5 micron resolution.

• Also used for calibration of cam angles and motion verification.

Page 5: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 5

Kinematics

•Girder is treated as a rigid body.

•Unique, invertable geometrical relations between the cams and the objects.

• Roller bearings on cams determine Q or BPM, and BFW transverse positions independently.

Page 6: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 6

Matlab Motion Control Programs

•CVS’d matlab routines for undulator motion control applications

• epics controls are also used

girderAngle2Axis girderCamSet girderAxis2Angle girderCamWaitgirderAxisFind girderAxisFromCamAngles girderGeo girderAxisMeasure girderLinearPot girderAxisMove girderLinearPotZero girderAxisSet girderLPOT2Axis girderBFWMove girderMotorStatusReadgirderBFWposition girderPositionPlotGui girder_bump girderPositionPlotGui girderCalReset girderQuadMovegirderCamAngleCalibrate girderQUADposition girderRangeCheckgirderCamMotorRead girderRotaryPot girderCamPot girderScoreField_Integral_GUi Field_Integral_GUI undulatorPositionPlotGuiundulatorPositionPlotGui moveUndulatorQuadrupole_guimoveUndulatorQuadrupole_gui scan_backlash segmentTranslatesegmentTranslateWait segmentTranslationStatus steer_undulator_guitaper_control und_quad_align UndKact UndKactMonitor UndulatorTaperControl

Page 7: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 7

Motion Checking

• Accuracy check based on linear potentiometers which are good to about +/- 5 microns.

• During initial system checkout, we found gross distortion in the motion due to software irregularities. (fixed)

Page 8: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 8

Calibration

• Linear potentiometer reading versus cam angle. Should be sinusoidal.

• Phase is determined by matlab software. Period is determined by ANL software.

Page 9: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 9

Calibration of Many

• Calibrate up to 33 cams at once, but still takes at least a half and hour per cam - often much more.

•One Linear pot is wired backwards in this picture.

Page 10: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

0

Calibration Irregularity

• This showed up a problem with the earthquake restraint bolts that were engaging the girder during the motion. (We fixed this problem)

Page 11: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

1

BBA Motion Control

• BBA corrections motions are typically ~10 microns or less.

•Corrections are applied to all 33 girder simulateously through matlab software.

Page 12: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

2

Undulator Pointing

• Can aim the x-rays by moving the entire undulaor line.

• Range is limited to about 1 mm (radius) at FEE.

Page 13: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

3

Tolerance Zones

• Plan from 2004

Zone 1Zone 1 (non-invasive correction) (non-invasive correction)•• 120-Hz 120-Hz trajtraj-feedback (LTU -feedback (LTU BPMBPM’’ss))•• 0.1-Hz 0.1-Hz trajtraj-feedback (und. -feedback (und. BPMBPM’’ss))

Zone 2Zone 2 ( (ΔΔtt >> 1 , hr 1 , hr⟨⟨PP//PP00⟩⟩ > 90%, - )non invasive > 90%, - )non invasive•• ( 5) MICADO best steering within undulator ( 5) MICADO best steering within undulator 3Zone 3Zone ( (ΔΔtt >> 24 , hr 24 , hr⟨⟨PP//PP00⟩⟩ > 75%, )invasive > 75%, )invasive

•• Weighted steering of undulator Weighted steering of undulatortrajtraj. (1 .)min. (1 .)min•• ... - (10 .)or quadrupole gradient scans fast BBA min... - (10 .)or quadrupole gradient scans fast BBA min•• - ( .)Possible x ray pointing few min - ( .)Possible x ray pointing few min 4Zone 4Zone ( (ΔΔtt >> 1 , wk 1 , wk⟨⟨PP//PP00⟩⟩ < 50%, )machine time < 50%, )machine time

•• (<1 )One iteration of BBA hr (<1 )One iteration of BBA hr 5 (Zone 5 (Zone ΔΔtt >> 6 , - )mo shut down 6 , - )mo shut down

•• (1 )Reset movers set to zero and manual realignment wk (1 )Reset movers set to zero and manual realignment wk•• 3 (~3 )Full iterations of BBA hrs 3 (~3 )Full iterations of BBA hrs

*Worst Case - noreliance on

position monitoringsystem

Page 14: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

4

Drift Rate

• < 1micron/day motion relative to neighboring BPMs

• Prediction (2004) +/- 0.5 microns/day from ground motion. (Weather also contributes a few-day time scales.)

Page 15: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

5

Girder Motion from ADS

•ADS (stretched wire) measurements of programmed girder motion

•>10 minutes per point

Page 16: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

6

Hysteresis in Girder Motion

• Extremely sensitive beam-based measurements show up to 1 micron of hysteresis.

•We may implement a correction cycle, but further understanding is needed.

Page 17: Undulator Motion Controls Jim Welch June 9, 2009 J. WELCH welch@slac.stanford.edu June 9, 2009 FAC, June 2009.

J. [email protected]

Undulator Motion ControlsFAC, June 2009 1

7

Summary

•Motion controls have been performing with accuracy and precision needed for BBA.

•New applications using motion controls are still being created.

• Preliminary indications of mechanical stability are favorable.