tmt.opt.pre.07.046.drf01 14 september 2007 1 requirements and conceptual design of m3 system ben...

14 September 2007 1TMT.OPT.PRE.07.046.DRF01

Requirements and Conceptual Design of M3 System

Ben PlattMyung ChoMark Sirota

14 September


Outline

Ben Platt – Overview and System Requirements

Myung Cho – Modeling Conceptual Mirror Support Design

Mark Sirota – M3S Control Systems Overview


Tertiary Mirror System (M3S) Overview and System Requirements

Ben Platt

14 September 2007


Outline

M3 System Decomposition

External Interfaces

M3S Overview

External Interfaces

M3 System Requirements


M3 System Decomposition

M3 System (M3S)M3 Cell Assembly (M3CA)

– M3 Mirror (M3M) {blank and polishing}– M3 Supports (M3SS) {actuators, load cells, cabling}– M3 Cell (M3C) {cell structure, trunnions}– M3 Control System - Cell (M3CSC) {electronics, software, sensors}

M3 Positioner Assembly (M3PA)– M3 Rotator (M3R) {Rotator Structure, Rotator Drive(s), Rotator Bearing,

Countermass}– M3 Tilt Mechanism (M3T) {Tilt Structure, Tilt Actuator, Tilt Bearings}– M3 Cable Wrap (M3CW)– M3 Control System - Positioner (M3CSP) {electronics, software,

sensors}

M3 Interface Panel (M3I) {electrical/fluid interface with Telescope Structure}


Structure (TMT.TEL.STR)

Optical Cleaning Systems

(TMT.TEL.OPT.CLN)

Optical Coating System (TMT.TEL.OPT.COAT)

Telescope Safety System

(TMT.TEL.CONT.TSS )

Power, Lighting, and Grounding

(TMT.TEL.CONT.POWR)

Optics Handling Equipment

(TMT.TEL.OPT.HNDL)

M3(TMT.TEL.OPT.M3)

Engineering Sensors(TMT.TEL.CONT.ESEN)

Test Instruments(TMT.TEL.OPT.TINS)

Telescope Control System

(TMT.TEL.CONT.TCS)

ICD-STR-M3

ICD-M3-CLN

ICD-M3-COAT

ICD-M3-TINS

ICD-M3-HNDLICD-M3-TCS

ICD-M3-TSS

ICD-M3-ESEN

ICD-M3-POWR

M1 (TMT.OPT.M1)

ICD-M1-M3

Summit Facilities (TMT.FAC.INF.SUM)

ICD-SUM-M3

Enclosure CraneDimension and Clearances

M3S External Interfaces

Draft copies of the ICDs will be made available for this study.


M3S Top Level Requirements

Provide 2 DOF articulation for alignment & to steer beam onto instrument

Provide rapid slew of M2 Mirror to switch beam between instruments

Provide smooth tracking to maintain beam on instrument, during observing

Maintain M3 Mirror figure in the face of changes in gravitational and temperature fields

M2CA

M2PA


M3 Cell Assembly (M3CA)

The M3CA consist of the Cell, Mirror and Mirror Support System.

M3CA


M3 Mirror Blank Requirements

Mirror Material:– low expansion glass

or grass ceramic flat mirror

M3 configuration:– Flat solid elliptical

mirror, CA = 3.470 m X 2.454 m

Blank Shape: – Plano – Plano


M3M - Polish

All figure requirements are with the mirror in the M3CA.

The figure requirement is completely described with a normalized Structure Function based on a Kolmogorov atmosphere, with tip/tilt removed.


35

0

230

2

500

r

mnmA

Where:

D(x) is the structure function and is in units of (nm)2

A = Leading coefficient = 211015

B = High frequency errors (surface roughness) = 2 nm

x = Separation between point pairs, similar to spatial frequency.

d = Diameter of beam footprint = 1.33 m

r0 = Fried’s parameter = 3.66 m

2323

5

42.375.136.10 Bd

x

d

x

d

xAxD

Where:

M3S Structure Function

Over any beam footprint d = 1.33m

M3 SQRT(D(x))

0

50

100

150

200

250

300

0.000 0.200 0.400 0.600 0.800 1.000

x/d

Sq

ua

re r

oo

t o

f D

(x),

(n

m)


Figure Parameters Derived from Structure Function

Parameters derived from Structure Function– RMS WFE = 168 nm– Surface Slope Error:

P-V = 1.69 µrad

RMS = 0.47 µrad


M3 Cell (M3C)

The tertiary mirror cell supports the M3M and M3SS. It also provides a reaction base for the active mirror supports.

Supports weight of mirror and mirror supports in any orientation of the telescope.

Functions as handling device for the tertiary mirror.

Stiffness shall be sufficient to support a M3S first resonant frequency of > 12 Hz.


M3 Support System (M3SS)Performance Prediction of NAOA Conceptual

Design

Myung Cho


Conceptual Design Parameters

Mirror – Flat solid elliptical mirror– Mirror thickness: 100 mm– Mirror mass: 2000 kg or less

Mirror support system– Elliptical patterns (hexa-polar)– Tri-axial support concept

60 Axial support (passive/active),

60 Lateral support (passive in X &Y)

Mirror substrate chosen to be solid flat 100 mm thick, to produce smooth print-through bumps that can be corrected by adaptive optics

60 hexa-polar support pattern

X

Y


M3 Support Concepts (Tri-axial )

M3 Support concept design (presented at M3 CoDR) with– Tri-axial support units that apply force vectors that intersect at the

mid-plane of the mirror– These were linked by hydraulic whiffle trees into six sectors that

provide support and definition in six DOF’s

load cell


Nominal support location (radial position):R1: 17%

R2: 40%

R3: 63%

R4: 86%

Support print-through in Z:– P-V surface: 58 nm– RMS surface: 11 nm

(entire surface)– Axial support in 2 groups:

218~220 N on R1 (inner most)

276~306 N on R2-R4

(note) support forces in each group are not the same

Axial support performance(mirror face up; gravity in local Z)

Support print-through Support forces


M3 Lateral Support

Surface error: gravity in -Y direction

9 nm P-V

1 nm RMS

Gravity

Gravity

Surface error: gravity in X direction

8 nm P-V

1 nm RMS


M3 Dynamic Performance

Natural frequencies and mode shapes (free-free)*

*First 10 mirror bending mode shapes are similar to low order Zernike polynomials

Mirror mass = 1750 Kg in the model

mode frequency mode shapeID (hz)

1 60.3 0 astigmatism 2 70.9 45 astigmatism 3 132.9 focus4 147.1 0 trefoil5 155.9 30 trefoil6 242.5 0 coma7 262.5 0 quadfoil8 267.9 45 quadfoil9 328.5 90 coma

10 388.1 2nd coma


Active support performance

M3 active supports can correct low order aberrationsFirst 10 mirror bending modes (natural modes) were modeled noise-free for a perfect system to determine

– Residual RMS surface error from Reference surface RMS of 1000 nm– Maximum actuator force to correct Reference surface– Gain (Reference RMS ÷ residual RMS)

RMS based on the entire optical surface

Reference Active Optics Correctionmode P-V rms P-V rms Fmax Gain

ID (nm) (nm) (nm) (nm) (N) 1 3998 1000 2.4 0.3 9.33 38972 4583 1000 2.5 0.3 12.05 34573 4138 1000 7.3 1.1 40.48 8804 5582 1000 18.0 1.8 56.04 5575 4988 1000 14.2 1.6 60.90 6086 4165 1000 37.4 6.2 113.01 1627 5212 1000 56.4 6.3 173.47 1598 5648 1000 52.0 5.7 190.30 1749 4963 1000 55.8 7.5 226.02 133

10 4211 1000 139.8 23.4 438.25 43


M3 Control System – Cell (M3CSC)

Mark Sirota


M3 Control System-Cell

Summary Description & Requirements– The M3 Control System–Cell (M3CSC) provides local control for the M3 Cell

Assembly (M3CA). – The M3CSC is independent and separate from the M3 Control System-Positioner

(M3CSP).– The primary external M3CSC control interface is with the Telescope Control System

(TCS) via a single Ethernet connection. – The M3CSC will meet all performance requirements over the following conditions.

Zenith angles between 0 and 65 degrees

Zenith angle rates up to 30 arcseconds/seconds

Temperatures between 2 and 15 degrees C

– The M3CSC will be capable of maintaining the M3 mirror figure without requiring zenith angle or temperature data from the TCS at rates any faster than once every 100 seconds.


M3 Control System-Cell

Summary Description & Requirements– The M3 Mirror shape will settle to its final shape within 15 seconds of any

change of Zenith Angle between 0 and 65 degrees.– “Cell Control” look up table (LUT)

Contains the set-points for each force actuator as a function of zenith angle and temperature.

The values contained in the Cell Control LUT are provided by the TCS.

Initial values for the Cell Control LUT will be developed during optical lab testing and supplied by the M3CA vendor.

Zenith angle and temperature are provided to the M3CSC by the TCS at a constant rate of ~ 0.1 Hz.

The M3CA won’t require complete calibration of the Cell Control LUT more frequently than once per year. Bias only corrections (zero point corrections) to the LUT will be allowed on a monthly time scale.


M3 Control System - Cell

Summary Description & Requirements– Calibration and Diagnostics

The M3CSC will provide a telemetry stream that consists of M3CSC parameters such as currents, sensor values, etc.

The M3CSC will include a diagnostic and calibration mode which supports

– control of individual actuators and the reading of individual sensors.– support the on-sky measurement of individual actuator influence functions

The M3CSC will have the capability of receiving and executing M3 Support command offsets from the TCS at rates up to once per second. (This will be used to gather data required to build a new Cell Control LUT)

– InterfacesControl and data transmission between the TCS and M3CSC will be via a single Ethernet connection.

All control, power, utility, utility interlocks, engineering sensor, and local control interfaces are via the M3 Interface Panel.

– E-Stop, Safety, and Fault Handling and Alarms


M3 Control System - Cell

M3

SUPPORTS

M3Cell

ControlProcessor

&Amplifiers

Cell Control Delta Forces

Zenith AngleTemperature

MIRROR

M3 CELL

Actuator Commands

Sensor MeasurementsTelemetry

Alarms and Faults

Control Commands

M3 Control System_Cell

M3 Interface Panel

E-Stop

Power

Coolant

M3 CableWrap

Power(if required)

Coolant(if required)

Local ControlEthernet Port

M3 Control System - Cell Functional Block Diagram

Σ

M3

MIRROR

CellControl

LUT(Forces)

(non volatile)

Engineering Sensors

Dat

a

Data

Cell Control LUTBuild and

Management

Cell Contol LUT Data

TelescopeControlSystem

TCS M3CS_Cell Adaptor

DataManagement

System

UtilityInterlocks

M3 Cell Assembly

ShapeMeasurements

Alignment &PhasingSystem

Shape to ForceTransformation

stars

Data

.


Continue with Overview and System Requirements

Ben Platt


M3 Positioner Assembly (M3PA)

The Positioner will articulate the M3CA in two (2) axes.

Points the science beam coming from M2M to science instruments, located at various positions on the Nasmyth Platform.

Tracks to keep the science beam positioned properly on a given science instrument, while observing through changing telescope angles.

Slews to new target and/or instrument.

The stiffness of the positioner shall be such that when carrying the mass of the M3CA, the first resonant frequency of the M3S is > 12Hz TBC. This shall apply to all possible orientations of the telescope.


M3PA Top Level Requirements

The tilt mechanism will provide articulation of M3M about the M3T axis, which is in the plane of the Tertiary Mirror optical surface, collinear with the minor axis of the outer elliptical profile of the M3M.

The M3 volume constraint is a 2.2 m diameter cylinder extending from the vertex of M1 a height of 1.5 m and a 3.5 m diameter cylinder extending to the top of the M3S.

3.5 m

2.2 m 1.5 m


M3PA Top Level Requirements

The M3 Positioner interfaces: – Telescope Structure on the lower end

– M3 Cell Assembly (M3CA) on the upper end. .

A rotator bearing is located on the bottom of the Positioner to provide smooth and accurate rotation of the Tertiary Mirror. This bearing is part of the Positioner.


M3PA Range of Motion

10 20 30 40 50 60 70

100 20 30 40 50 60 70Zenith Angle (degrees)

Zenith Angle (degrees)

M3 Tilt Trajectories

M3 Rotation Trajectories

0

0

-10

10

20

30R

ota

tion

An

gle

(d

eg

ree

s)

45

40

50

55

60

Tilt

An

gle

(d

eg

ree

s)

Tilt range: 50° +/- 8 °

Rotation range: +/- 180 °

– Must address instruments on both Nasmyth structures

– Additional range required for servicing

Tilt

Rotation


M3 Positioner – Rotator (M3R)

The M3S azimuth bearing supports the mass of the M3S in all possible orientations of the telescope. It also defines the position of the tertiary mirror (M3) with respect to rotation about the telescope optical axis. The outer diameter of the bearing shall be 2.2 m. The inner diameter shall allow personnel access for maintenance of the M3S.The bearing shall be capable of supporting the mass of the M3M, M3C, M3 Support System (M3SS). Rotator


M3 Positioner – Tilt Mechanism (M3T)

The tilt mechanism is a 1-D tilt mechanism and shall rotate about an axis in the plane of the mirror, coincident with the short axis of the ellipse and perpendicular to the optical axis of the telescope.

The M3 tilt mechanism shall have a smooth slew and tracking mode with controlled accelerations to meet the requirements stated in the M3 Control System – Positioner (M3CSP)*.

*See presentation on M3CSP

Tilt Mechanism


M3 Cable Wrap (M3CW)

Utility lines (power, cooling, pneumatic, hydraulic (TBC)) as well as signal lines traverse the Interface between the M3PA and the telescope structure.

These lines must be routed through a cable wrap, provided on the M3S, near the Interface, to allow for rotation at this Interface without damage to the lines.

The cable wrap may go on either side of the azimuth bearing but must not block servicing access.


M3 Access

Ladder inside M3 tower

– M1 floor extends to inside of M3 tower

– M3 and M1 not shown for clarity in figure

– hoist attachment point for lifting equipment


M3 Interface Panel

TMT will provide an interface panel for connecting all cables, wires and hoses.

The interface panel may be located on either side of the rotator bearing or in the tower.


M3 Control System – Positioner (M3CSP)

Mark Sirota


M3 Control System-Positioner

Summary Description & Requirements– The M3 Control System–Positioner (M3CSP) provides local control for the M3

Positioner (M3P). – The M3CSP is independent and separate from the M3 Control System-Cell

(M3CSC).– The primary external M3CSP control interface is with the Telescope Control

System (TCS) via a single Ethernet connection.– The M3CSC will meet all performance requirements over the following

conditions.Zenith angles between 0 and 65 degrees

Zenith angle rates up to 30 arcseconds/seconds

Temperatures between 2 and 15 degrees C

– The M3CSP will receive and execute rotation and tilt position commands from the TCS.


M3 Control System - Positioner

Summary Description & Requirements– Calibration and Diagnostics

The M3CSP will provide a telemetry stream that consists of parameters such as currents, sensor values, etc.

The M3CSP will include a diagnostic and calibration mode which supports control of individual actuators and the reading of individual sensors.

– InterfacesControl and data transmission between the TCS and M3CSP will be via a single Ethernet connection.

All control, power, utility, utility interlocks, engineering sensor, and local control interfaces are via the M3 Interface Panel.

– E-Stop, Safety, Fault Handling, Alarms



Core performance characteristics– These numbers are representative and will be updated over the next several weeks.

Requirement Value Comment

Travel Range

Tilt +/- 8 degrees

Rotation +/- 180 degreesRepeatability

Tilt 1500 m-arcseconds

Rotation 3000 m-arcseconds

Piston 175 µ-meters RMSDifferential Accuracy

Tilt 200 m-arcseconds RMS

Rotation 200 m-arcseconds RMS

Piston 30 µ-meters peak

Max change in piston with simultaneos tilt and rotation

moves (< 15 arcseonds).Jitter

Tilt 100 m-arcseconds RMS

Rotation 100 m-arcseconds RMS

Piston 5 µ-meters RMS With trend removedTracking Speeds Tilt +/- 5 arcseconds/second Rotation +/-10 arcseconds/secondSlew Time < 2 minutesSettling Time < 10 seconds

Turnarounds can occur(tracking trough zero speed)

over 15 arcseconds

over the full travel range

Command minus M3 actual with trend removed



.

M3Rotator/Tilt

ControlProcessor

&AmplifiersM3 Rotator Positions

Rotation & Tilt

Zenith angleTemperature

Telemetry

Alarms and Faults

Control Commands

M3 Control System-Positioner

M3 Interface Panel

E-Stop

PowerCoolant

M3 Cable Wrap

Power(if required)

Coolant(if required)

Local ControlEthernet Port

M3 Control System – Positioner Functional Block DiagramD

ata

AlignmentMeasurements

Data

M3 Positioner Control

stars TCS

TCS M3CS_P Adaptor

APS

DMS

UtilityInterlocks

M3 Positioner Assembly9/5/2007

.

.

M3

TILT

MECHANISM

Limit and Home Switches

Rotator Commands

M3

ROTATORRotator & Tilt Commands

Rotator and Tilt Encoders

Engineering Sensors

Pointing Kernel

Positiondata

Transformation to delta

mechanical angle

Dat

a

Limit Switches

tmt.opt.pre.07.046.drf01 14 september 2007 1 requirements and conceptual design of m3 system ben...

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