HLS going mobileDevelopment and test of a mobile HLS system
14th International Conference on Accelerator AlignmentESRF Grenoble 3 -7 October 2016
P. Bestmann CERN
Outlook
04/10/2016
• Scope & motivation
• mHLS strategy
• Sensor setup
• First tests
14th International Conference on Accelerator Alignment
Scope & motivation
• Why making a Hydrostatic Levelling System mobile?
• We loose the advantages in terms of precision!
• We keep all the advantages in terms of automation!
• Vertical measurements of the Collimator Survey Train were derived from wire sag models.• This is only possible in very limited dimensions and configurations.
• Control of environment and wire parameters.
• Preparations for a Train Version 2• More flexible solution for wire offset measurements (see talk A. Behrens)
• Alternative solution for vertical measurements.
04/10/2016 14th International Conference on Accelerator Alignment
mHLS strategy
• Available Sensors• Capacitive sensors
• Floater or needle based sensors
• Ultrasonic sensors
• Ultrasonic Sensors already emerged in water• Developed and produced by DESY
• Very good for a mobile application
• Smart self calibrating strategy using silica glass references
• Limited in range, extension is difficult
• We need sensors with 250mm range
04/10/2016 14th International Conference on Accelerator Alignment
mHLS strategy• Combination of different systems
• Giving 250mm range
• Keeping HLS sensor range reasonable small
• Minimizing systematic errors
• Lightweight linear translation stage
• Absolute optical scale
• Composite pot for DESY HLS sensors
• Fully filled 10mm diam. Tube
• Free air system
04/10/2016 14th International Conference on Accelerator Alignment
mHLS Sensor
04/10/2016
Support
ReferencePiece
Optical ScaleRead-head
Composite pot
Transducer
R1R2
WS
D1
D2
D3
𝐻𝐻 = 𝐷𝐷2 − 𝐷𝐷1𝑊𝑊𝑆𝑆 − 𝑅𝑅1𝑅𝑅2 − 𝑅𝑅1
14th International Conference on Accelerator Alignment
mHLS Sensor
04/10/2016
Standard socket
Optical scale
Translation stage
HLS pot
• Base, table, scale and reference piece is one assembly
• Changing transducer or pot does not affect system constants
Motor & Driver
Scale readhead
14th International Conference on Accelerator Alignment
• Rack for electronics• DESY MPE2 Unit
• PXI + touchscreen
• Power supplies + UPS unit
• Batteries
• 2 x 18m Tubes
• Pinch Valve
Infrastructure
04/10/2016 14th International Conference on Accelerator Alignment
• Automatic sequence• Adjust theoretical height difference using stage
• Open valve
• Monitor stabilisation process
• Measurement process
• Verification process
Operation
04/10/2016 14th International Conference on Accelerator Alignment
Software
• Realised in LabView• DAQ Oriented
• Hardware integration
• High level functionalities and controls
• Modular architecture• Object oriented
• Using Actor Framework
• Automatic processing• Aquisition
• Statistics & Controls
• Documentation
04/10/2016 14th International Conference on Accelerator Alignment
Laboratory Tests
• Lab tests are showing results as expected
• System is stable in Lab environment
04/10/2016 14th International Conference on Accelerator Alignment
Tests
• What about real conditions?• Temperature differences
• Ventilations issues
• Pressure differences
• Stabilisation issues
• Transport
• Handling
• Measurement time
• Autonomy
04/10/2016 14th International Conference on Accelerator Alignment
LHC Tests
04/10/2016 14th International Conference on Accelerator Alignment
LHC Tests
• Adress practical issues• Transport
• Handling
• Autonomy
• Stabilisation
• Time
• Stability• Zero Offset
• Statistics
04/10/2016 14th International Conference on Accelerator Alignment
Zero Offset
04/10/2016
Average 1.179mmRMS 0.045mmMin 1.103mmMax 1.293mmRange 0.190mm
14th International Conference on Accelerator Alignment
Repeatability
04/10/2016
Average 0.003 mmRMS 0.003 mmMin 0.000 mmMax 0.019 mmRange 0.019 mm
14th International Conference on Accelerator Alignment
Next steps
• Improvements of cable & tube protection
• Differential pressure measurements inside the pots• Shield
• Membrane
• Airtube
• Temperature effects due to the huge water column• The temperature in the LHC is rather stable
• Temperature differences between the two tubes are very small
• Automation tests with robotic arm
04/10/2016 14th International Conference on Accelerator Alignment
The full content of this presentation would not have been possible without the valued
contributions of all those involved
Thank You