Chinese SONG progress and

its design introduction

Guomin WangGuomin Wanggmwang@niaot.ac.cn gmwang@niaot.ac.cn

2011-9-162011-9-16 Nanjing Institute of Astronomical Optics & Nanjing Institute of Astronomical Optics &

TechnologyTechnology

SONG 4SONG 4thth Workshop Workshop College of CharlestonCollege of Charleston

Outline:

Progress introduction

Telescope design introduction

PROGRESS INTRODUCTION

August 13,

2010:

Finished the

PDR

December 25,

2010:

Finished the CDR

Now, we are…

Structure

constructing

Now, we are…

mirror fabrication

Mirrors material test report from

Russia LZOS

Preparing

Large bearing manufacturing

Azimuth bearing φ680 ×φ880 × 80

Delivery time: 4 months

Large bearing

manufacturing

Altitude bearing φ240 ×φ320 × 38

Delivery time: 4 months

Preparing contract for long-term elements, such as . . .

Torque motors

Encoders

Telescope schedule

Item Schedule Status

Preliminary Design

Review

Aug., 2010 Closed

Critical Design Review Dec., 2010 Closed

Factory Acceptance Nov., 2012 On going

Ready for Shipment Dec.,2012 . . .

On site Acceptance Apr., 2013 . . .

TELESCOPE DESIGN INTRODUCTION

General requirements

Cassegrain system;

M1: paraboloid, 1m clear aperture, Zeodur material,

active support and close-loop controled through S-H;

M2: hyperboloid, fused silica material, active positioned

by 5-DOF unit;

M3: flat mirror, Zeodur material, 180°turn to direct the

light to different Nasmyth platform;

System ratio: F/36.7;

General requirements Image quality: 80% energy encircled in 0.3″ @ lucky

imaging focus ； Nasmyth focus: VIS camera (450 - 650nm), RED camera

(650 - 1000nm), Focus monitoring camera (< 450nm),

auxiliary focus;

FOV @ Nasmyth: R32.52″ ； Coudé focus: spectrograph (480 - 680nm);

FOV @ Coudé: 10″ ；

ADC: doublet prism;

Optical derotator: three - mirror

General requirements Range of azimuth: 0 º ～ ±220º;

Range of altitude: 10 º ～ 89º

Max. acceleration: 2 º/sec2 ;

Max. pointing speed: 20 º/sec;

Blind spot: 2 º (diameter);

Tracking accuracy: RMS 0.3″ , 90s, no guiding ； Pointing accuracy: RMS 5″, 70 º ≥ ZD ≥ 1 º;

Repeat pointing accuracy: ≤ RMS 1″, 70 º ≥ ZD ≥ 1 º;

First frequency: large than 8 Hz;

General view

F/36.7 layout

F/36.7 parameters

Item ParametersM1 ф1000Primary ratio F2.3System ratio F36.667Primary focus length 2300System focus length 36666.8 （ λ=546.1nm ）FOV R32.52″M1-M2 distance 2100 mmM2–M3 distance 1600 mmM3–focus distance 1588.3 mmWorking wavelength VIS （ λ=450 ～ 650nm ）

RED （ λ=650 ～ 1000nm ）

F/36.7 imaging quality after ADC

Spot diagram of VIS @ ZD = 5 °

F/36.7 imaging quality after ADC

Spot diagram of VIS @ ZD = 45 °

F/36.7 imaging quality after ADC

Spot diagram of VIS @ ZD = 75 °

F/36.7 imaging quality after ADC

Spot diagram of RED @ ZD = 5 °

F/36.7 imaging quality after ADC

Spot diagram of RED @ ZD = 45 °

F/36.7 imaging quality after ADC

Spot diagram of RED @ ZD = 75 °

Nasmyth optical design

From telescope

To Coudé

Nasmyth structure

Cou

dé o

pti

cal d

esi

gn

From telescope

Coudé structure

Optical elements list

Item Size （ mm） Material CoatingAccuracy

Qty.

M1 φ1030x75 Zeodur AL λ/50 1

M2 φ96x25 Fused silica AL λ/60 1

M3 φ76X15 Zeodur AL λ/60 1

M4 φ30x5 Zeodur AL λ/60 3

M5 φ54x8 AL Zeodur λ/60 5

Wedge prism

φ40x6,∠5° H-LAK10/H-ZF1

450-1000nmantireflection λ/60 2

K mirror 1 60x44x10 Zeodur AL λ/60 2

K mirror 2 36x30x8 Zeodur AL λ/60 1

Dichroic mirror 1

φ30x3 Fused silica450-620nm (R)680-1000nm (T)

λ/30 1

Dichroic mirror 2

φ30x3 Fused silica450-620nmHalf-reflection λ/30 1

Item Size （mm）

Coating Material Accuracy Qty.

Field lens 1 φ20x4 Antireflective H-K9L N=1, ΔN=0.1

1

Field lens 2 φ20x5 Antireflective H-K9L N=1, ΔN=0.1

1

Achromatic lense1

φ20x7.5 Antireflective H-K9L/H-ZF2 N=1, ΔN=0.2

1

Achromatic lense2

φ20x7.2 Antireflective H-K9L/H-ZF2 N=1, ΔN=0.2

1

Achromatic lense3

φ38x7.5 Antireflective H-K9L/H-ZF2 N=1, ΔN=0.2

1

Achromatic lense4

φ22x7 Antireflective H-K9L/H-ZF2 N=1, ΔN=0.2

1

Achromatic lense5

φ24x9 Antireflective H-K9L/H-ZF2 N=1, ΔN=0.2

1

Achromatic lense6

φ22x7.2 Antireflective H-K9L/H-ZF2 N=1, ΔN=0.2

2

Protect mirror φ54x8 Antireflective Fused silica λ/10 3Dichroic prism 32x32x

32Antireflective Fused silica λ/10±10″ 1

Dichroic mirror 4 φ32x3 Half-reflective Fused silica λ/10 1Tilt mirror φ32x5 Al 480-680nm Zeodur λ/20 1Filter φ22x3 480-680nm Fused silica λ/10 3

Basem

en

t S

tru

ctu

re

Constrained the 8 fixed anchor bolts;

Applied 3.5 t on the bearing place to simulate the above weight;

Apply 1g on the structure; Apply 700N on the place of

1373mm from the bearing to simulate the wind force at 15 m/s;

Max. stress: 49.92 Mpa

Max. deformation: 0.022 mm

Levelness adjustment

Rated load(N)

Max. load(N)

Unit torque(Nm/104N)

Adjustable height of adjusting bolt

(mm)

Adjustable height(mm)

Unit weight(kg)

20000 60000 2.5 0.25 5 7

Table 2-1 Parameeters of iron pad

Azimuth bearing

TypeCrossed roller bearing

d 680 mm

D 880 mm

H 80 mm

Axial runout < 0.02 mm

Radial runout < 0.02 mm

Axial sitffness 5000 N/m

Radial stiffness

10000 N/m

Tilt stiffness 450000 Nm/mrad

Azimuth encoder

Azimuth motor

Friction torque: 67.5N.m ； Inertial torque: 50N.m ； Wind torque: 139N.m ；

Swiss Etel Company:

TMB0450-100;

Rated torque: 561Nm;

Rated current: 11.3A;

Max. deformation: 0.042mm

Constrain nodes connecting to bearing;

Add 1180N on top surface of center section to simulate the above weight;

Add 5390N on the down surface to simulate the down weight;

Add 1g to the structure; Apply 400N at the place of

149.5mm above center section to simulate the wind force;

Max. stress: 12.64 Mpa

M1 support ￠ 1010mm, thickness 45mm, center hole 65mm, flat bottom;

Axial supporting:

Fixed supporting: 3;

Pneumatic active supporting: 33 (6+9+18);

Lateral supporting: 10 counterweight level;

R1 = 151.72mm, F1 = 28.664N ;

R2 = 296.5mm, F2=31.183N;

R3 = 449.12mm, F3=36.775N;

Mir

ror

cell c

alc

ula

tion

Max. stress: 2.9 MPaMax. deformation: 0.58 um

For

ce a

ctuat

orD

iaphra

gm

Air

C

ylin

der

(Bel

lofr

am)

Electro- pneumatic regulator

SMC Regulator

Force sensor

M2 positioning unit

Δx (ΔY) ±7 μm

ΔZ ±3μm

Δθx(Δθx) ±20″

43

M1-M2 offset calculation

θ° uy （ um ） uz （ um ） Rotx(″)

0 0.00 11.71 0.00

10 1.52 11.57 0.14

20 2.79 11.15 0.27

30 3.80 10.44 0.39

40 4.56 9.44 0.50

50 5.10 8.13 0.58

60 5.46 6.51 0.65

70 5.68 4.59 0.70

80 5.79 2.41 0.73

90 5.83 0.00 0.74

Uz-altitute angle Uy-altitute angle Rotx-altitute angle

Fre

quency

ca

lcula

tion

Mode Frequency (Hz) Mode shape

1 24.8 Fork lateral

2 26.8 Fork fore-and-aft

3 46.4 Truss lateral

4 52.2 Truss fore-and-aft

5 54.5 Top ring torsion

6 73.7 Center section

Con

trol arc

hit

ectu

re

TCS configuration

Master Computer (Advantech Industrial PC)

Slave Computer(UMAC)

M2 control configuration

Communication

3-D Of SONG telescope

THANK YOU !!!THANK YOU !!!