An Inspection Vehicle for the CMS Detector 1

An Inspection Vehicle for the CMS Detector 1 Bas van Otterloo tt BACKGROUND IMAGE, MODERN, CLASSIC, MINIMALISTIC, ETC. Frank Glege 1

Who am I? • Education: research physicist • At CERN since ~20 years • Since 2001 working on the CMS Detector Controls System • Current position: CMS DCS coordinator

LHC 3

Compact Muon Solenoid The CMS detector Length: ~20 m Diameter: ~15 m Weight: 12500 t Magnet: 4 T superconducting 20. 10. 2015 Frank Glege 4

Standard model of particle physics

Particle detection 6

CMS Detector Controls System • SCADA: Win. CC OA developed by ETM • ~6 million parameters • ~700. 000 lines of code • ~35000 finite state machine nodes • ~34 SCADA systems • 29 redundant PC pairs (Windows) • ~50 DB schemas (ORACLE) • O(TB) of data in schemas 7

WHY AN INSPECTION VEHICLE? RADIATION TIME AND MONEY TOPOLOGY During operation of the LHC there is no access. Shutting down LHC costs time and money. The cavern topology doesn’t allow for easy camera coverage. 8

Challenges • Radiation • The probability of radiation disturbing the electronics of the device are low enough to ignore this aspect. • Magnetic field • The fringe field is estimated to ~300 m. T. • Limited WIFI coverage • The vehicle must be able to run partly unattended • No access during long periods (weeks) • The vehicle must be able to recharge itself and be safe. • Limited space • The vehicle should be able to drive under the detector and should therefore be “small”.

ELECTRIC MOTORS usually neodym 10

e y l v d l i e s a e n c i p e s g n p r x a n i E e o h g c n u e e q l r l M o a T h c Piezo electric Fly wheel !

BRUSHLESS MOTOR Hall probes exchanged by photo sensors for magnetic field tolerance 12

MOTOR CONTROLLER 13

DEVELOPMENT MAGNETIC COMPENSATION 14

ELECTRIC MOTORS • Common electric motors use magnetic forces to turn. • The fringe field of the CMS magnet can exceed the field strength inside the motor. usually neodym Turning part with variable field -> variable force Turning part with fixed, strong field -> fixed force 15

Field of CMS magnet ELECTRIC MOTORS Requires field stronger than CMS magnet field to turn 16

Raspberry Stereo. Cam 17

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THANK YOU! QUESTIONS? 19