automated beamline alignment at elettra xray diffraction...

$: Automated beamline alignment at Elettra Xray Diffraction ...ftp.esrf.eu/scisoft/BioXHIT/Workshop_030504/bioxhit_030504_Rober… · Roberto Borghes, Roberto Pugliese BioXHIT Workshop,$
Roberto Borghes, Roberto Pugliese BioXHIT Workshop, ESRF 2004

Automated Automated beamlinebeamline alignment at alignment at ElettraElettra XrayXray Diffraction Diffraction BeamlineBeamline

BioXHITBioXHIT Workshop on Automated XWorkshop on Automated X--ray Provisionray Provision

Roberto BorghesRoberto Pugliese

Experiments DivisionSoftware for MeasurementsSincrotrone Trieste S.C.p.A.


AGENDAAGENDAAGENDA

• The XRD beamline automatic alignment problem

• Applying the Teleo-Reactive Control theory

• Implementation and first results• Future development


SCENARIOSCENARIO

Slits

57-PolesWiggler

Graphite Filters

Si Crystals Monochromator

Three SectionToroidal Focusing

Mirror

Ion chamber detector

XX--Ray DiffractionRay DiffractionBeamlineBeamline atat ElettraElettra


The Ion Chamber detectorThe Ion Chamber detector

• Two ionisation chambers separated by a thin Beryllium foil

• DIFFERENCE of Signal1 and Signal2 estimates beam vertical position

• SUM of Signal1 and Signal2 estimates beam flux

• GOAL: maximize SUM & minimize abs( DIFF )


Why a Feedback?Why a Feedback?

High temperature Si-Mirror deformation

Slow drifts of Storage Ring Electron Orbit

0.5

0.6

0.7

0.8

0.9

1

01:22 01:48 02:14 02:40 03:05 03:31 03:57 04:23 04:48 05:14 05:40 06:06

Detected Beam Flux

Storage Ring Current

Slope = -0.1

Slope = -0.44


Automatic Beamline Alignment:Automatic Beamline Alignment:problem solving strategyproblem solving strategy

• Split the alignment problem into small sub-problems involving, for example, only one optical element and the associated sensor

• Implement for each sub-problem an alignment module using traditional or soft computing techniques

• Combine the modules using the strategic, behavioural knowledge of the optics expert

OEnSource Exp.Ch.OEn-1OE2OE1S

0S1

S2

Sn-1

Sn

Sn+1


Applying Intelligent System Concepts to the Applying Intelligent System Concepts to the Automatic Automatic BeamlineBeamline Alignment problemAlignment problem

• Intelligent Systems (IS) incorporate the creative, abstract and adaptive attributes of a human while minimising the undesirable aspects such as unpredictability, inconsistency, fatigue, subjectivity and temporal instability

• Hybrid Intelligent Systems integrate Knowledge Based Systems, Neural Network, Fuzzy Systems, Evolutionary Algorithms, Case-Based reasoning, Chaos Theory and traditional techniques to solve effectively complex real world problems.


TeleoTeleo--Reactive (TR) controlReactive (TR) control

• TR control occupies a region between feedbackcontrol and discrete action planning:– actions can be either discrete or continuous– actions are not guaranteed to achieve their goals – actions can be interrupted in response to changes in the

environment

• TR plans can be represented as a sequence of condition-action pairs called TR operators.– TR plan execution is adaptive and opportunistic:

conditions are evaluated from top to bottom and theaction associated o the first true condition is performed.

C0 A0

C1 A1

Cn An

Ci Ai


TR control planTR control plan

Everything OK? Do nothing

Conditions Actions

Beamdown ? Stop everything

Flux OptimizationNeeded?

Start/Stop FluxOptimizer

Flux Feedback Needed ?

Start/Stop background Flux Feedback

Beam CenteringNeeded ?

Start/Stop background Position Feedback

Prio

r ity


0

0.5

1

1.5

2

2.5

3

3.5

4.05 4.25 4.45 4.65 4.85 5.05 5.25 5.45

Mirror Motor Position

The actions: OffThe actions: Off--line Flux Optimizerline Flux Optimizer

Measured Beam Flux

COARSE LARGE

INIT

FINEMEDIUM

EXIT

+

_

bad

bad

bad

bad

_

__

+

++

- stepFWD( )- stepREV( )- initLARGE( )- restore( )

50 motor steps

1º - COARSE STEP search till negative slope

5 motor steps

2º - MEDIUM STEP search till negative slope3º - FINE STEP search till negative slope

1 motor step

Max


The actions: Position FeedbackThe actions: Position Feedback

Toroidal Mirror

ION chamber detector

Correction Algorithm

Stepper Actuator

Photon beamExperimental

Station

Signal DIFF

Toroidal mirror

ION chamber• Background Continuous feedback minimize abs(DIFF)

• Correction Algorithm is not enabled if DIFF < threshold

• Backlash recovery procedure for Stepper Actuator

• Not a fast feedback (period = 2 sec)


Si-Crystal mirror

ION chamber

The actions: Flux FeedbackThe actions: Flux FeedbackSi-Crystals

MonochromatorION chamber

detector

Linear Regression Algorithm

PiezoActuator

Photon beamExperimental

Station

Signal SUM

• Background Continuous feedback

• Linear Regression Algorithm calculates sign and gain of the correction signal

• Buffer size for LR: 5 samples

•Piezo Actuator avoids backlash problems

• Not a fast feedback (period = 1 sec)

Monochromatorsecond crystal

alignment system

Piezo actuator

microstepper


Applying the Model Reference Applying the Model Reference architecture to architecture to beamlinebeamline

Beamline

Automatic Beamline Alignment

Sensors Actuators

Beamline Control System

Incr

easi

ng In

telli

genc

e

Incr

easi

ng P

reci

sion

Teleo Reactive Controller

Elettra XCS

ION chamber detector Toroidal mirror

and Si-Crystal


XCS XCS : : ElettraElettra beamlinebeamline control systemcontrol system

XCScore

VACOmodule

VRZmodule

tcpsmbs_srhttpd

GALILmodule

GEF2008module

DBconfigureinstead of

programmingLog

archive event

corbatangoepics


XCS python librariesXCS python libraries• pyXCS: Very easy access to XCS• pyFSM: Finite State Machine library• pyTRC: Teleo Reactive Control library

# very small sample of use of XCS class

from pyXCS import *

x = XCS()x.open('bcs102.elettra.trieste.it')a = x.get('frontend_machine_machine_1_accucurr')print 'Accumulated current =', a[0], a[1]x.close()


XRD Control PanelXRD Control Panel

AutomaticBeamlineAlignment

Control

BeamlineValves Control

Tool Launcher

Manual FluxOptimizer

MonochromatorControl


First ResultsFirst Results

0.5

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01:22 01:48 02:14 02:40 03:05 03:31 03:57 04:23 04:48 05:14 05:40 06:06

Detected Beam Flux


0.85

0.87

0.89

0.91

0.93

0.95

0.97

0.99

1.01

1.03

14:59

:3615

:00:37

15:01

:3915

:02:40

15:03

:4215

:04:44

15:05

:4515

:06:46

15:07

:4815

:08:48

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:5015

:10:51

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:5215

:12:55

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:5615

:14:57

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:5815

:17:00

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:0215

:19:03

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:0515

:21:07

15:22

:0815

:23:10

15:24

:1315

:25:15

15:26

:1615

:27:18

15:28

:19

Detected Beam Flux


WITHOUT Automatic Alignment

WITHAutomatic Alignment


First ResultsFirst Results

0.85

0.87

0.89

0.91

0.93

0.95

0.97

0.99

1.01

1.03

1.05

10:0

7:08

10:0

8:40

10:1

0:12

10:1

1:44

10:1

3:17

10:1

4:49

10:1

6:22

10:1

7:53

10:1

9:26

10:2

0:59

10:2

2:31

10:2

4:04

10:2

5:36

10:2

7:08

10:2

8:40

10:3

0:12

10:3

1:44

10:3

3:17

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4:51

10:3

6:23

10:3

7:55

10:3

9:26

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0:58

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2:30

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4:02

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5:35

10:4

7:07

10:4

8:39

10:5

0:12

10:5

1:45

10:5

3:18

10:5

4:49

10:5

6:21

Detected Beam Flux


0.98

0.99

1

1.01

1.02

1.03

1.04

17:54

:2917

:57:03

17:59

:3618

:02:11

18:04

:4518

:07:19

18:09

:5218

:12:26

18:14

:5918

:17:33

18:20

:0618

:22:39

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:1318

:27:47

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:2118

:32:55

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:3018

:38:03

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:3718

:43:10

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:4418

:48:17

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:5018

:53:24

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:5718

:58:31

19:01

:0519

:03:38

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:1219

:08:45

Detected Beam Flux

Storage RingCurrent

Automatic Alignment“ramping”

Non Linearity due to mirror deformation


Future DevelopmentsFuture Developments

• Refactoring of the software libraries in order to be BIOXHIT ready

• Integration with BLU-ICE• Towards the one button beamline and

EVC integration• Integration of MarrResearch Cryogenic

Sample Changer ?!?


AcknowledgementsAcknowledgements

• Edoardo Busetto, Fulvio Bille’, Kristina Djinovic, Sandy Grulja from ELETTRA

• Doriano Lamba, Alberto Cassetta from CNR

automated beamline alignment at elettra xray diffraction...

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