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2012.03.21, CLIC Test Module Meeting
Status of the DB Quad adjustable support design – flexures and
regulation units tests
Mateusz Sosin
CLIC Module WG Meeting, 18-September-2013
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
DB Quad adjustable support – short review
5DOF regulation thanks to flexure based supports 3 adjustable in vertical 2 adjustable in horizontal + 1 support with
constant length
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Wedge based regulation 30mm of wedge move = 2mm
of ‚leg’ stroke Expected resolution ~2µm Expected precision
(considering thread backlash) ~5µm
DB Quad adjustable support – vertical regulation unit
Flexural vertical support with wedge-profiled head
Threaded wedge
Flexural vertical support sliding bearing
Wedge sliding bearing
Belleville spring stack Regulation screw
Regulation screwbearing unit
(2 flat needle bearings+ tightening screw)
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
DB Quad adjustable support – radial regulation unit
Differential threadregulation screw
Flexural horizontal support.One end threaded
(as a part of regulation screw)DB Quad platform clamping block
Differential thread based regulation 20 revolution of screw = 2mm of
horiz.support stroke Expected resolution ~2µm Expected precision (considering
thread backlash) ~10µm
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
DB Quad adjustable support – longitudinal joint
Flexure based joint Blocks longitudinal displacements
of the DBQ platform Allows vertical and horizontal
displacements + rotations (within assumed range)
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
DB Quad adjustable support – flexures and regulation units tests
Development STEP 1: Adjustable - vertical regulation unit tests Adjustable – radial regulation unit tests Longitudinal „blocking” flexure tests
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Development STEP 2: Final design and of 5DOF platform prototype Tests with ‚dummy’ DB Quad Development STEP 3: Update of design according to the STEP1,2 tests results Final DBQ series for CLEX
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
FLEXURES AND REGULATION UNITS TEST ADAPTER
Test bench desscription
Existing ZTS linear actuators test bench used Additional adapters desighed to provide flexures
and regulation units tests Flexures bending by transversal table Suited LabView acquisition data logging software
written
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Vertical regulation unit tests
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Vertical regulation unit tests - stiffness
Measurement conditions Load up to 55kg (20%
more than max flexure load)
4 series with step ~10kg
Elongation measured by 50nm resolution RENISHAW linear scale
Stiffness of test bench components considered as negligible
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Stiffness → ~5kg/µm
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Vertical regulation unit tests - resolution
Measurement conditions Manual adjustment using imbus
key Measurements in the middle and
25% wedge position Load ~47kg Observation of regulation
ergonomy wrt. resulting position change
Results 1µm regulation resolution
achieved without any problems. Fine position adjustment within 2..5 seconds
0.1µm regulation resolution feasible with longer regulation time
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Vertical regulation unit tests – linearity, backlash repeatability
FW
BW
Theoretical position
Measurement conditions 3 iterations FW-
BW Load ~47kg Wegde pos.
Measured directly by SYLVAC (1µm resolution) probe
Results Repeatability
~5..7µm Non-linearity
~10µm Backlash ~15µm
Note: Observed „dead-zone” of SYLVAC proble at the level of ~3µm, so real repeataility should be better than mentioned above
RE
PE
AT
AB
ILIT
Y
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Vertical regulation unit tests – impact of wegde bending for unit adjustment
Results +/- 1mm perpendicular deflection of flexure gives max. 8µm of longitudinal displacement. It is
coherent with theoretical calculation for flexure geometry
+/-1mm (deflection)
Δl
Measurement conditions 2 deflection iterations FW-
BW Load ~47kg deflection measured directly
by SYLVAC (1µm resolution) probe, regulated by hand
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Vertical regulation unit tests - summary
Results Parameters of vertical regulation unit much better than
expected (especially resolution and regulation ergonomy) Position stable in the time Assumed components tolerances and sliding bearings
tolerances (H6/h5, minimal or no sliding bering perpendicular backlash)are correct.
Actions foreseen Add grease grooves in V_FLEXURE_BEARING Integrate wedge absolute position indicators/sensors –
needed for ergonomic regulation. Potentiometric sensors forseen
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Radial regulation unit tests
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Radial regulation unit tests - stiffness
Measurement conditions Load up to 55kg (20%
more than max flexure load assumed)
4 series with step ~10kg
Elongation measured by 50nm resolution RENISHAW linear scale
Stiffness of test bench components considered as negligible
Stiffness → ~2.5kg/µm
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Radial regulation unit tests - resolution
Measurement conditions Manual adjustment using imbus
key Measurements in the middle
and 25% wedge position Load ~39kg Observation of regulation
ergonomy wrt. resulting position change
Results 3µm regulation resolution easily
achieved. Fine position adjustment within 2..5 seconds
1µm regulation resolution feasible with longer regulation time
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Measurement conditions 3 iterations FW-BW Load ~39kg Rotation measured by
encoder adapted to the regulation key:
Results Repeatability
~15..20µm Non-Linearity ~10µm Backlash ~45µm
Note: ENCODER-REGULATION SCREW connection had a big backlash and wasn’t stiff – what could be the source of analysis error. Real performance shall be better than measured. Will be checked during DBQ support platform tests, using integrated sensors
FW
BW
Theoretical positionR
EP
EA
TA
BIL
ITY
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Radial regulation unit tests – linearity, backlash repeatability
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Aadial regulation unit tests – impact of wegde bending for unit adjustment
Results +/- 1mm perpendicular deflection of flexure gives max. 5µm of longitudinal displacement. It is
coherent with theoretical calculation for flexure geometry
+/-1mm (deflection)
Δl
Measurement conditions 2 deflection iterations FW-
BW Load ~39kg deflection measured directly
by SYLVAC (1µm resolution) probe, regulated by hand
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Radial regulation unit tests - summary
Results Resolution satisfactory. Repeatability and linearity to be
confirmed with additional sensors Regulated position stable in the time
Actions foreseen Need to increase the threads tolerances. More tight thread
fitting. Smaller Ra needed to avoid thread seizure. Grinding of threads on steel components. Threads sets fitting during manufacturing
Prestress of the flexures to suppress thread backlash Integrate differential screw absolute position
indicators/sensors – needed for ergonomic regulation. Potentiometric sensors forseen
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Longitudinal flexure tests
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Longitudinal flexure tests – stiffness, buckling
Measurement conditions Load up to 85kg (stress
in flexure ‚thin’ section ~270MPa)
4 series with step ~10kg
Elongation measured by 50nm resolution RENISHAW linear scale
Stiffness of test bench components considered as negligible
Stiffness → ~1.4kg/µm No buckling appear
during flexure pressing (even when exciting flexure center with perpendicular force ~10N)
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Results Position given by flexure stable in the time Observed position drift, when deforming flexure from
extreme to extereme transversal position (-1mm...+1mm) at load of 50kg. Possible linked with plastic deformation in bending area. Simulated max. stress ~1100MPa (close to elasticity limit of spring steel defined as flexure material 1.0909 Re=1400MPa)
Actions foreseen Optimize shape to decrease stress in bending areas (higher
stress safety margin) Check possibility of better material use Confirm if delivered flexures material correspond to specified
Longitudinal regulation unit tests - summary
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
Actions foreseen – STEP2/STEP3
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests
Integrate wedges position sensors within vertical regulation units
Increase the threads tolerances. More tight thread fitting. Smaller thread surface Ra
Integrate differential screw absolute position sensors/indicators
Optimize flexure shape to minimize stress in bended areas
Mateusz Sosin Concept of ‘hexapod type’ DB Quad adjustable support
CLEX integration – remarks
Single actuator rotation (90 or 180˚) needed According to the collision
between one flexure support and actuator connector box – the rotation of actuator is needed
Considered as non conflicting with other installations (to confirm)
Mateusz Sosin Status of the DB Quad adjustable support design – flexres nad regulation units tests