1. GE alternative and outcome
Beniamino Di Girolamo
2nd LESS Collaboration Steering Committee – 3 November 2018

2. Design basic facts
GE Inspection Robotics is a specialized company in robotics
It is a joint venture with ETH Zurich and it was a spin-off company of ETH
The design is based on the inchworm concept where during the treatment the main body of the robot stays still and a motor performs the very precise steps for the helix of treatment over 2 cm at the time
When the complete 2 cm are done, the central part of the body is clamping and the main body released. The same motor moves the main body to the next position (macro-step), clamps and the treatment starts again
B. Di Girolamo - GE alternative - 03/11/2017

3. Design basic facts
B. Di Girolamo - GE alternative - 03/11/2017

4. Design basic facts carriage electronics box (E-Box) AC 24V
V AC
optical fibre
Ethernet
robot position
laser enable
laser ON
carriage
electronics box
(E-Box) AC
24V
robot control
umbilical, m
24V DC
V AC
valves
N2 flow
N2 (3...8 bar)
pneumatics box
(P-Box)
pressure (6 bar)
3x PP tubes
B. Di Girolamo - GE alternative - 03/11/2017

5. What we get from the company
A fully tested and commissioned carriage ready for the integration with the optics
The carriage is based on only two motors and clamps
The translation without gears to have zero-backlash
The rotation with a pre-loaded gear to eliminate backlash
A pneumatic-clamping system
The low level control system
The pneumatic box
We will participate to commissioning to expedite the hand-over
B. Di Girolamo - GE alternative - 03/11/2017

6. Remaining risks and mitigations
Consequence
Implemented mitigation
Risk Level
Poss. Mitigation
Traction not sufficient
Robot slips  inaccurate pattern
limit and monitor motor force; large clamping force
moderate
check w/ prototype
additional slip sensor
Disturbance from stepping too large
small disturbed zone on laser pattern every 20mm
active compensation in SW
Centering of fibre inaccurate
laser focus not on ideal circle, but inclined
adjustment screws for fibre head; fix orientation of fibre head
low
Centering of robot in BS inaccurate
changing focal distance, inclination of pattern
system failure during operation
writing process connot be completed
have spare system – implicit with different sizes
disturbance of / friction from umbilical too large
slip or uncontrolled decentering of robot
decouple umbilical from scanning slider/head
acitive, controlled umbilicial retraction, umbilical on low-friction sliders
play in robot to large
inaccurate pattern, double perforations
B. Di Girolamo - GE alternative - 03/11/2017

7. Milestones and deliverables
Date
Start
Principal approach fixed
LESS Concept
Released
Concept description w/ more detailed design, inkl. mechanics, control, user interface
Interfaces w/ CERN defined
Risk assessment  Concept release
LESS Design Released
Detailed Design (Mech., Electr.)
SW Architecture
Optics integration fixed
 Feature Freeze  Release Design
Prototype production Documents
Long lead items ordered
 Release for manufacturing
Prototype built
Prototype running and lab tested
 System ready to hand over
System Verified
System commissioned, basic tests run at CERN
Performance verified
Review
B. Di Girolamo - GE alternative - 03/11/2017

8. Planning
Schedule is tight however the company started the final drawings production after the review to be able to finally deliver to us the carriage ready to use by ~ January 26th
The participation to the commissioning will shorten the integration with the higher level control and synch with laser done by Dundee
Caveat: the dimension of the fibre head needs to be reduced to allow enough excursions for the clamps. The fibre has to soon go back to the producer
B. Di Girolamo - GE alternative - 03/11/2017

9. The review report is attached to the agenda
Outcome of the review
The outcome is positive and the reviewers indicated the points to consider
The carriage proposed by GE Inspection Robotics is an industrialized item and will enable us to meet the deadline for the preparation of a beam screen by end February 2018 as well as to arrive to the HL-LHC International Review for the e-cloud suppression with a treated racetrack LHC beam screen
The review report is attached to the agenda
B. Di Girolamo - GE alternative - 03/11/2017

10. Proposal
We adopt this solution to meet the 7 mm precision in translation and to be able to produce in February an automatically treated beam screen
We can optionally procure a second carriage for redundancy to reduce the risks and to be able to independently work on it in parallel in case any problem would arise during the treatment in Dundee. The cost is very reasonable
B. Di Girolamo - GE alternative - 03/11/2017