D2-118470-2 ANALYSES OF THE DYNAMIC DOCKING TEST …

NASA CR-

D2-118470-2

ANALYSES OF THE DYNAMIC DOCKINGTEST SYSTEM FOR ADVANCED MISSIONDOCKING SYSTEM TEST PROGRAMS

(NASA-CR-140286) ANALYSES OF THE DYNAMIC N74-337751DOCKING TEST SYSTEM FOR ADVANCED MISSIONDOCKING SYSTEM TEST PROGRAMS (BoeingAerospace Co., Houston, Tex.) 96 p HC Unclas$8.00 CSCL 14B G3/11 49641

THEfW COMPANY

HOUSTON, TEXAS

August .30, 1974

DOCUMENT NO. D2-118470-2

ANALYSES OF THE DYNAMIC DOCKING TEST SYSTEMFOR ADVANCED MISSION DOCKING SYSTEM TEST PROGRAMS

Contract NAS 9-13136

August 30, 1974

Prepared by

R. M. GatesJ. E. Williams

Approved by

R. K. NunoTechnical Program Manager

BOEING AEROSPACE COMPANY

Houston, Texas

D2-118470-2

REVISIONS

RSV. DESCRIPTION DATE APPROVEDSYM _ _ _ _ _ _ _ _ _ _ _

ii

Foren HOU-3-l i 6 (tLAB) Aproved 11/67 AJT

D2-118470-2

ABSTRACT

This document presents the results of analytical studies performed in

support of the design, implementation, checkout and use of NASA's Dynamic

Docking Test System (DDTS) during the period July 1, 1973 to June 30, 1974.

Included are analyses of simulator components, a list of detailed opera-

tional test procedures written, a summary of simulator performance, and an

analysis and comparison of docking dynamics and loads obtained by test and

analysis.

This report was prepared for the National Aeronautics and Space Administration

by Boeing Aerospace Company in fulfillment of the requirements of Exhibit B

of Contract NAS 9-13136.

KEY WORDS

Docking Simulator

Dynamic Docking Test System (DDTS)

Hydraulic Actuators

Servosystems

Structural Analysis

System Analysis

iii

D2-118470-2

TABLE OF CONTENTS

PARAGRAPH PAGE

REVISIONS ii

ABSTRACT AND KEY WORDS 1ii

TABLE OF CONTENTS iv

LIST OF ILLUSTRATIONS v

LIST OF TABLES vii

REFERENCES viii

1.0 INTRODUCTION 1

2.0 BACKGROUND INFORMATION 2

2.1 DDTS DESCRIPTION 2

2.2 APOLLO SOYUZ TEST PROJECT DOCKING SYSTEM 2

3.0 SYSTEM ANALYSES 6

3.1 STRUCTURAL ANALYSES 6

3.2 SINGLE ACTUATOR ANALYSES 8

3.3 ACTIVE TABLE ANALYSES 26

3.4 TOTAL SYSTEM STABILITY ANALYSIS 42

4.0 DETAILED OPERATIONAL TEST PROCEDURES 51

4.1 PROCEDURES DOCUMENT CONTENTS 51

4.2 TEST REQUIREMENTS AND OPERATIONAL TEST PROCEDURES 52

5.0 ANALYSIS OF DOCKING DYNAMICS AND LOADS 55

5.1 DEVELOPMENT TESTS 55

5.2 10 HZ INVESTIGATION 72

5.3 US/US QUALIFICATION TEST 80

6.0 CONCLUSIONS AND RECOMMENDATIONS 87

iv

D2-118470-2

ILLUSTRATIONS

FIGURE PAGEr

2-1 DDTS Simulator Facility 3

2-2 System Block Diagram of DDTS 4

2-3 ASTP Docking Mechanism 5

3-1 Single-Axis Servo Block Diagram 9

3-2 Displacement-to-Pressure Frequency Response 10

3-3 Circuit Diagram, Twin Gyrator Notch Filter 11

3-4 Twin Gyrator Notch Filter Frequency 12Response

3-5 Single Actuator Frequency Response, 13Displacement Open Loop

3-6 Single Actuator Frequency Response, 14Pressure Open Loop

3-7 Single Actuator Frequency Response, 16Closed Loop

3-8 Single Actuator Frequency Response, 17Including Rate Command

3-9 Single Actuator Closed Loop Frequency Response, 19Foreward Loop Gain Variation

3-10 Single Actuator Frequency Response, Position 20Open Loop, Hydraulic Bleed Orifice Variation

3-11 Single Actuator Frequency Response, Pressure 21Open Loop, Hydraulic Bleed Orifice Variation

3-12 Rate Command First Order Lag Filter Characteristics 22

3-13 Single Actuator Frequency Response, Including 23Rate Command Filter A

3-14 Single Actuator Frequency Response, Including 24Rate Command Filter B

3-15 Rate Command Notch Filter Characteristics 25

.3-16 Single Actuator Frequency Response, Including 27Rate Command Filter C

3-17 Table Displacement Frequency Response 29

3-18 Table Accelerations, Frequency Response Test 30

3-19 Actuator Accelerations, Frequency Response Test 31

3-20 Angle Limit Abort Switch 33

3-21 Table Coordinate System and Definition 35of Actuator Lengths

v

D2-118470-2

ILLUSTRATIONS (Continued)

FIGURE PAGE

3-22 TABGEOM Listing 38

3-23 Limit Switch Setting to Prevent Table Fall 41Through, Actuator 1, 3 and 5

3-24 Limit Switch Setting to Prevent Table 41Fall Through, Actuator 2, 4 and 6

3-25 Total System Block Diagram 43

3-26 Total System Stability, Near Full Extension 47

3-27 Total System Stability, Full Extension (Tension) 48

3-28 Total System Stability, Full Retract 49

5-1 Typical Test/Analysis Correlation, US-USSR Development 62Test, USA Active Case 3, Hot; X Force on CSM C.G.

5-2 Typical Test/Analysis Correlation, US-USSR Development 63Test, USA Active Case 3, Hot; Y Force on CSM C.G.

5-3 Typical Test/Analysis Correlation, US-USSR Development 64Test, USA Active Case 3, Hot; Z Force on CSM C.G.

5-4 Typical Test/Analysis Correlation, US-USSR Development 65Test, USA Active Case 2, Hot; X Force on CSM C.G.

5-5 Typical Test/Analysis Correlation, US-USSR Development 67Test, USA Active Case 2; Y Force on CSM C.G.

5-6 Typical Test/Analysis Correlation, US-USSR Development 69Test, USA Active Case; Z Force on CSM C.G.

5-7 Effect of Rate Command Gain on Load 75

5-8 Effect of Rate Gain on Peak Load, Case 16 77



5-11 Typical Test Results Without Rate Command Filter 81

5-12 Typical Test Results with Notch Fitler in Rate 82Command Line

5-13 US-US Qualification Case 9 (-Y Miss, High Energy) 83Without RAte Command Filter (a) and With NotchFilter (b)

vi

D2-118470-2

TABLES

PAGE

3-1 SINGLE ACTUATOR PARAMETERS 18

3-2 FLOOR SWIVEL JOINT LOCATIONS 40

3-3 ACTIVE TABLE SWIVEL JOINT LOCATIONS 40

5-1 US/US DEVELOPMENT TEST CONDITIONS 57

5-2 US/USSR DEVELOPMENT TEST CONDITIONS 59

5-3 LOCATION OF DOCUMENTED TEST DATA US/USSR 60DEVELOPMENT TEST - USSR ACTIVE

5-5 US/USSR DEVELOPMENT TEST DATA/MATH MODEL COMPARISON 71

5-6 US/US QUALIFICATION TEST CONDITIONS 84

5-7 US/US QUALIFICATION TEST DATA MATH MODEL COMPARISON 85

vii

D2-118470-2

REFERENCES

1. Boeing Document D2-118470-1, "Analysis of the Dynamic Docking TestSystem for Advanced Mission Docking System Test Programs," August1973.

2. Boeing Document D2-118544-1, "Mathematical Model for the Simulationof Dynamic Docking Test System Active Table Motion," August 1974.

3. Boeing Document D2-118544-2, "Dynamic Docking Test System ActiveTable Motion Computer Program, NASA Advanced Docking System (NADS),"August 1974.

4. Boeing Document, D2-118546-1-, "Dynamic Docking Test System ActiveTable Frequency Response Test Results," August 1974.

5. Boeing Document D2-118465-1, "Assembling, Integrating and Editingthe Checkout Test Requirements and Detailed Test Procedures for theDynamic Docking Test System," June 1973.

6. Boeing Document D2-118482-1, "Assembling and Editing OperationalTest Procedures Utilizing Administrative Terminal System for theDynamic Docking Test System," January 1974.

7. Boeing Document D2-118482-2, "Assembling and Editing OperationalTest Procedures Utilizing Administrative Terminal System for theDynamic Docking Test System," January 1974.

8. IED 50009-1, "Apollo Soyuz Joint Development Test Plan, DockingSystems

9. Structural Test Branch, Johnson Space Center, Houston, Texas, ES6

10. USA WG3-018, "DDTS Joint Development Test Data, USA Docking SystemActive," January 29, 1974.

11. USSR WG3-022, "DDTS Joint Development Test Data USSR Docking SystemActive," January 22, 1974.

12. Boeing Memorandum 5-2920-HOU-087, "Joint US/USSR Development TestData/Math Model Correlation," dated August 30, 1974.

viii

D2-118470-2

1.0 INTRODUCTION

This report presents the results of analytical studies performed between'

July 1, 1973 and June 30, 1974 to fulfill the requirements of Contract

NAS 9-13136. The purpose of this R&D contract was to perform system

analyses, to provide general technical support for implementation of

NASA's DDTS, and to assemble detailed operational test procedures.

Included in this report are:

a. Structural analyses of simulator components

b. Servo actuator performance studies

c. Active table motion analysis

d. System stability analysis

e. Analysis of docking dynamics and loads

This work is a continuation of the work performed between July 3, 1972 and

June 29, 1973 under Contract NAS 9-13136 and documented in Reference 1.

-1-

D2-118470-2

2.0 BACKGROUND INFORMATION

2.1 DDTS DESCRIPTION

The DDTS is a large motion, real-time docking simulator built by NASA JSC

for full-scale testing of advanced docking systems. Figure 2-1 illustrates

the hardware configuration of the DDTS simulator. Docking motions are

simulated by virtue of six linear hydraulic actuators driving the active

table. Each actuator is capable of an 84-in. stroke. Note that because

of the hardware geometry, table displacements can be much larger than the

displacement capability of an individual actuator. Interaction forces

between the docking mechanisms are measured by load cells and transmitted

to a hybrid computer which contains rigid body equations of motion that

predict the responses of the two docking vehicles. The real-time spacecraft

motions are then transformed to equivalent actuator motions which are then

transmitted as commands to the hydraulic servosystems. Figure 2-2 illus-

trates the sequence of events and interactions between the primary system

components.

2.2 APOLLO SOYUZ TEST PROJECT DOCKING SYSTEM

The Apollo Soyuz Test Project (ASTP) docking mechanism is illustrated in

Figure 2-3. The mechanism would be in the retracted position .on the passive

docking vehicle and the extended position on the active docking vehicle.

The three guides on each spacecraft serve to align the spacecraft to the

.proper orientation. Upon docking ring contact, the capture latches are

triggered, holding the passive vehicle to the active docking ring. The

active docking ring is then retracted until the structural latches and body

latches are activated. The body latches retain the docking ring in the

retracted position while the structural latches hold the two spacecraft

together.

-2-

7 APOLLO/SOYZ DOCKING %4.CNANISU

i411

jr

-- a

__- , I ___ .- hJ

S+X

* K

UPE SvE JIN

SECTI N -LOAD C

BA-SUPER TRCT RE TALE

cr ro

00

______-- ~qj$ZcI U

/ UPPEQ SWIVEL JOINT

0

RETRAC;ED ATJ C*7 I ow-uu

LOWER SWIVEL DINT T

'4./------ I 0 ._ _T

7vICw A-A \2\356,!E SAY 10133

Figure 2-1. DDTS Simulator Facility

FigureC 21 DDSSmat r aility

INITIALCONDITIONGENERATOR

SPACECRAFT

SMOTIONS ACTUATOR MOTIONS

SPACECRAFT TRANSFORMATION COMMANDEQUATIONS TO SERVOSYSTEM COMPUTATIONOF MOTION MOTIONS

SERVOCOMPUTER COMMANDS

SIMULATOR FACILITY

SERVOSYSTEMS -

SERVOHARDWAREMOTIONS

FORCE FEEDBACK I DOCKINGARTICLE

Figure 2-2. System Block Diagram of DDTS

BASE ASSEMBLYSPRING THRUSTER -.

BODY-MOUNTEDLATCH

CAPTURE LATCH CABLE RETRACT SYSTEM WIRE BUNDLEARTICULATING SUPPORT

STRUCTURALLATCH ASSEMBLY

INTERFACESEAL i

ATTENUATORASSEMBLY

RETRACTED

00

GUIDE 2k

GUIDE RING

EXTENDED

Figure 2-3. ASTP Docking Mechanism

D2-118470-2

3.0 SYSTEM ANALYSES

3.1 STRUCTURAL ANALYSES

This section contains a brief discussion of miscellaneous stress and

stiffness analyses conducted to substantiate the structural adequacy of

DDTS components not completed when the Reference 1 document was published.

The intent of this section is not to present a formal analysis of each

structural component analyzed, but to summarize the results of the analyses

and verify that the structural integrity of the components was investi-

gated and that they do comply with the design criteria established for

the DDTS.

3.1.1 Docking System Mass Properties Simulator

The mass properties simulator as originally designed, Dwg. SAY 44101320*

dated March 2, 1973, was found to be structurally inadequate from both a

strength and stiffness standpoint. However, by adding the clamp assembly

defined in Dwg. SAY 44101346 for stiffness and by adding stiffness in the

cylinder-to-mass support rod attachment point area, the as-built mass

properties simulator is structurally acceptable. The natural frequency

of the system is estimated to be around 60 Hz and will, therefore, not

couple with simulator structural dynamics. After the above-mentioned

modifications were incorporated, the bending strength in the area of the

attachment points was also adequate.

3.1.2 Actuator Check Valve and Manifold Block

A stress analysis was performed on the manifold block, Dwg. SDF 36111292j

and check valve (modification - Teledyne Republic Modification P/N 412-

1D2-6) shown in Dwg. DDTS 620.

*Denote NASA-JSC drawings

-6-

D2-118470-2

3.1.2 (Continued)

Analysis of the manifold blocks showed that they will be structurally

adequate as long as the pressurized passages are no closer than .2 inch

to adjacent holes.

The modified check valve was also found structurally adequate with the

following factors of safety:

Factor of Safety

Working Proof BurstPressure=3000 psi* Pressure=4500 psi* Pressure=7500 psi*

Ultimate 4.97 3.31 1.99

Yield 3.57 2.38 1.43

*Teledyne specification

3.1.3 Adapter for USSR Docking Mechanism on DDTS

The subject adapter, Dwg. SAY 44101319, was analyzed and found to be

structurally adequate.

3.1.4 DDTS Environmental Enclosure

A detailed analysis of the environmental enclosure, Dwg. SAY 44101431,

indicated that all components of the structure, including the standpipe,

are structurally adequate with respect to both strength and stiffness.

-7-

D2-118470-2

3.2 SINGLE ACTUATOR ANALYSES

The single-axis servo loop mathematical model discussed in Reference 1 was

revised to include differential pressure feedback*. The block diagram of

this linear math model is shown in Figure 3-1. This model was used to

perform open and closed loop analyses of the servo loop and to establish

actuator parameters for the six-degree-of-freedom table motion model which

will be discussed later.

3.2.1 Transfer Functions

The displacement-to-pressure transfer function was derived from linearized

actuator equations and modified by experimental data. Figure 3-2 shows a

comparison of test and analysis data for the displacement-to-pressure trans-

fer function.

The forward loop notch filter is a twin gyrator filter designed to attenuate

the command signals at the natural frequency of the servo valves (120-150 Hz).

The circuit diagram of the twin gyrator notch filter is shown in Figure 3-3.

Frequency response characteristics of this filter are shown in Figure 3-4.

3.2.2 Open Loop Analysis

Open loop frequency response-data were obtained for both the pressure and

displacement feedback loops. Analytical data were obtained using the

single-axis servo loop model, and test data were obtained to establish and

verify analytical parameters. Test results were obtained by applying a

sinusoidal signal to the valve driver in the forward loop and recording

the output of the linear position potentiometer and the differential

pressure transducer. Comparisons of test and analytical open loop data

are shown in Figures 3-5 and 3-6, respectively.

-8-

K s RATE COMMAND SNOTCH FI TER SERVO VALVE

ACTUATOR DYNAMICS

(c ) DOUBLE 2 +1 1 1 Xpf + R +2s+1 K3s+K2 Ms2+B s

FILTER ,v/ Wv "

As

PRESSURE COMPENSATION DISPL.-TO-PRESS.

+ co

+( s/ 1 Ks(C s+1) (C s+1)

K0

2(S/ ) 2+D s+1

RATE COMMAND NOTCH FILTER n s_ Vol.s s2+Dds+1 3 4

DOUBLE NOTCH FILTER = (s2 + 51680.)(s 2 + 725690.)(s2 + 533.3 s + 51680.)(s 2 + 533.4 s + 725690.)

Figure 3-1. Single-Axis Servo Block Diagram

02-118470-2

REPRODUCIBILITY OF THE

ORIGINAL PAGE IS POOR

30

20

10

-20

-30

.1 1. 10. 100.

/ FREQUENCY, HZ

Figure 3-2. Displacement-to-Pressure Frequency Response

-10-

D2-118470-2

30 K 30 K?

30 K Q 30 KU

.03 L .02f f

7.5 K 7.5 K1

7.5 KQ lpf 7.5 KQ lpf

Figure 3-3. Circuit Diagram, Twin Gyrator Notch Filter

-11-

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FREQUENCY, HZ

Figure 3-4. Twin Gyrator Notch Filter Frequency Response

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Figure 3-5. Single Actuator Frequency Response, Displacement Open Loop

Hill f P, -4 1 TIO

1111 1 i.II I ' I I I

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Figure 3-6.- Single Actuator Frequency Response, Pressu're Open Loop

D2-118470-2

3.2.3 Closed Loop Analysis

Using the actuator parameters obtained from the open loop analysis, the

closed.loop frequency response shown in Figure 3-7 was obtained. Also

shown in the figure is a comparison of analytical data with test. These

responses were obtained by using a sinusoidal position command only.

Analytical results using both position and rate commands are shown in

Figure 3-8. Actuator parameters established by this analysis are presented

in Table 3-1.

Test data were also obtained for variations in forward loop gain and

hydraulic bleed orifice size. Figures 3-9 through 3-11 show the results

of these parameter variations.

3.2.4 Effect of Rate Command Filters

As a result of the development tests (see Section 5.0), various filters

were incorporated in the rate command line of each actuator to eliminate

unwanted 10 Hz oscillations. The effect of these filters on single actuator

performance was obtained analytically.

Filter A and filter B are first order lag filters with corner frequencies

of 1 Hz and 5 Hz, respectively. Frequency response characteristics of

these filters are shown in Figure 3-12. Also shown in the figure are

filter A characteristics with increased gain. The effects of these filters

on single actuator frequency response are shown in Figures 3-13 and 3-14.

Using filter A on the rate command has the effect of increasing the gain

slightly at low frequencies (less than 5 or 6 Hz)'and attenuating higher

frequency signals. Filter B amplifies the response slightly at frequencies

below 10 Hz.

Filter C is a notch filter with a notch frequency of 9.5 Hz whose

characteristics are shown in Figure 3-15. Single actuator frequency

response characteristics using filter C with nominal and double rate gain

-15-

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FREQUENCY, HZ

Figure 3-7. Single Actuator FrequencyResponse, Closed Loop

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~FREQUENCY, HZ

Figure 3-8.. Single Actuator Frequency Response, Includi'ng Rate Command

D2-118470-2

TABLE 3-1

SINGLE ACTUATOR PARAMETERS

"VALVEPARAMETER

POSITION PRESSURE CLOSEDOPEN LOOP OPEN LOOP LOOP

M = effective mass 1.25

AREA = average piston area 7.8

VOL = hydraulic volume 541.

Be = equivalent bulk 105modulus

Bp = actuator viscous 40.damping coefficient SAME AS SAME AS

K2 = K + Cp = valve .0125 POSITION OPEN POSITION OPEN

pressure flow coef- LOOP LOOPficient + leakagecoefficient

v = servo valve equiva- .7lent viscous dampingratio

Wv = servo valve resonant 879.2frequency

C1 .01326

C2 displacement-to- .0159

C3 pressure transfer .3183

C .022C4 function coefficients .022K p .0676

Kg = forward loop gain 32.7 32.7 48.46(amplifier & servovalve)

Kf = position feedback gain .25 0. 1.

Kpf = pressure feedback gain 0 1. .015

Wpfl pressure N.A. N.A. 18.85

compensation N.A. N.A. 628.32Wpf2 filter constants

Krc = rate command gain 0 0 .0128

-18-

W AbI~ ) )

ti ii, ii e i ,clIt I H lIll

Hl 1 1 IM I ilH II I Ii i

0 2 0 1 XA i II I Jill I I 1111 Ill illi

!I ll 1

i, , i iitl i I ii (

200 I I I i !i

11 Ji0 llJill 1 11 11;

LU

Sil MHi

S -80 0 1 11)7LD 0i I Iii I

A lii ,i,, ! ! 11 i !111

"ti i Jil itt ii iii : it

1. 19 100

F R NHC HZ

i ll I i I Jil I llw Iii iii! iv, -80 0 kr r uI

XV MI X I1 1 11 1 li

M IM ili ,

Forward Loop Gain Variation

lit it il! ilil ! ! i ! i

•-120 - I -0 !!1

'~~ i) " 'lili i(( ii

iii I ill i .

ii! i ( i i-160I ii € i

1. 10. 100.

FREQUENCY, HZ

Figure 3-9. Single Actuator Closed Loop Frequency Response,Forard Loop Gai n Vari ation .

-< +'+ !m "l . . . ' [ '+ '10 F.L --- 14' Ii 1, [1 11J4JJ' Li t..III

II I' i,.H i l H 1 111 Il 1 1 11 1 1 1 i l l Ii. I I I ~ Ii iiii 1I ii i; I llli II'

iI.i IJ~i II I I I .i if . I I I ii I I'Il 1 i I I I'L

HI I 'Ili i l i11ii . Ill HI I I 1 1 1 I ' I I

II , ,II I i' Iii . I1 I i/-

I -lii I 1 1 I iii i I I I I I

Si I I i H M !11 1 1filli . IrI iI II il i fIil i 1 '-I ' "I I ii: i i II i

ii I I I I I II-90 -t

If I ,-~ -1i 1 I 1 L fII illU~

I Io If I I I I I 1 illill i-1, ,if i ,il+

I - I iII -- lr'i I iilll ili'0"i l I I . . I I i l 1_120 - -20 If I I 11111 1 I I III iII III 1i1111IIII 111 i Wi '11 1 : 111II \~~ 2I II

Iii 1 1i i fi iii If hi IISI JiI ' iil I i

- 91 0 - - 3 0 1,1 ' ' -,111 11111 1 1 1 ilil 1 14 , I I il i li 11l 1 1 1 h.. i ii Ill

::::: H, ilt :+

J ill Hi ll ll ll III I I I I I I I If Ill I II I I0l i 1i if I 1 I 1 11 1 11 1 1 f l I I II 1 .1 11 , I I :I. IM I ii .L1 . .. . .I1 1 I, iI tl

t ;:v VII , I L 1 U_0 4 I f

iI I-1 0 - 0 .. i i I i I I ...

i ll I I I I - I f l I l l * I 1 1 1 i l 1 1 j

ti-i- I - -+-- 1 i'-u--

' II+:,. -++J++ _p ,: i'H ' I. .. .. .... .I

I I I II I I ,,1, ,i l i I I I I f I II

i ll t - I 1 J I I I II i i

I~ I 11

J ill L ill 11: 1;

I I I .I i O ii

-++ I i ... +" + I11:111 ': ;i !li +1+ !1 I I i iI i I I ! l!+ I i l II li ll

li t+,m -. I ,,, i i I Ii ..... ,, ±i~

m'~~ ~~~~~ ,,., Ii il it i ii I ,, I+

1. 10 100.~~TJ FREQUENCY, HZ

,,i~~~~lm~i $ i,~ I; ill iI

Figure 3-10. Single Actuator Frequency Response, Position Open Loop,SHydraulic Bleed Orifice Variation

03 i. I0. l00.

© FREUENCY, HZ

~Figure 3-10. Single Actuator Frequency Response, Position Open Loop,Hydraulic Bleed Orifice Variation

w C a L O u 4 0 O- ~ h L. .c Ut O) Y 0 O IO

II Iif Ii I i

H ill Ili illI I I I Ill 1 1 Il 11 1 I I I I I I l l I I I I I1 11 11114 I I I I II i li i I I

II , !II .11M ) III I I 11 1II )i r I' II I I; i 1 1 1 1 1 11 i 111 ,li 111

11 I I I I II ilI t , II I',

i p I I ,, l I~

1I 1 1i ,., I 1 1i III 1rI M i I il il i ;I ! ' li]

I I I II I I il l l1111i 111

-20 .I I I I I I m l III

I2 H il i1 1 1 1 i k IA i - 1 1 H l H i II1 1 1 I ! 11' l1 1 111 1 1 11 ll T,

I 1 1 I t i : iiIt It Ill 1 1-1I

I I I I II II III I ii Iii

20.1 I 1i11I20 il IlI !' I I i i

.... II Iil I i I

H il Ill 1 1 1 1 ) 1 1i I !. I III H11,lI i I Iii Illiiii ii I

-4 ,M I II IN, !i 11-4 j 0I IH

11: 1 111 ii il H,- -, I , H iii ii i

"J 10: ' i ~i

-I0l60 I 1 i I I II I I i I I I- 6 0 1_ F'-L 1!1 ;1 1 1 1 i L

III H l i, I I 1 1 li 1 1 .i .,-60 I Fl I Ii i I II N1 ri i

0 1 1 l I 1 1 ll Iit11 H 1i ;111 Wii

I -ll I II ii I II I

0 'iH i I 1I I 1 H ilI I

I! ii iiiii I II I

L-0

I I I ,I I i I I I I* I I I V I I K I.'I i 1 1 1

-80 2Ii ,,, , i I I. lii

i II Ii IIt-10 I I I 11 1 I I I I I I II HI 11; 11-A - I I I I 1111 1 1 i l I I 'II ;

L I Ill Ill 1 1 1 1 1 1 11 11 1111 1111 ll I i I il l :11h ill m ii l l

.1 0 0 H I I I I I I I I I I I 1 11 ;Ili 1ITTE I I

-2 I I I0f -20 ....

I. 10. 100.FREQUENCY, HZ

Figure 3-11. Single Actuator Frequency Response, Pressure Open Loop,Hydraulic Bleed Orifice Variation

1H 11 !!11! . 111 If E T 10I I I I i lIil1,1 1 1 11 Il I I "IHII I 1 1 . Ii ii l Pi l I I H l 1 1 1 1 1 1 ' 1 1 . l ! I I I ii

- II -.li!

i-- ii I I ! l l i iMll M! B -Li

20 111 I 1N I lii I I II II Ii I~'I;I111, ',I Hill', !, I I I III I'I'1IH'b I I I I iiii,

I [II IIIIII I 1 1

-1 0-t .ll~ illli 1! I ! I I l ! I

I I

ill! 1h 1 100.F Jigure 3ll 12 Rate Cma Firs Orde Lagl Fiter1. Characterit i.

Mi i i i i i i Ill .l I Il Jil "i I! " 14

Hil 1 i ltI~ il; I i

!! l!lil l ,I ~ t I I I IILI 1 1" l l 11 ,I : v

1 1 H ill1I I

I H il L II I I i I I l

- 3 0 1.. . ... Ill Jill-r i ,

.i k I0. I00

FREQUENCY, HZ

Figure 3-12. Rate Command First Order Lag Filter Characteristics.

CI soi, f , -0 C)

0 20 H "l YI K i -- -I l ill t 4il' W li --- -T n~4 i st T r li '- 1 "1.

, 'H llI IIt 1..I i

1i... i.i. ...2 0 ......... . T ,I i V; I : : :

...... .i i

iTi

* I ....: __ 7 3 I -'.. ._-_ .

I I ii1i t111 ji

I : f i I : i "

S if. 3 x RATE GAIN "ii .... Ili ii ,: i{ j;;42 x RATE GAIN; il i .-l--LL

- -=,: .. i! NOM. RATE GA N,,I I--I

.. .. I N ii-- - -

-80 1 0 ! 4 : ,r . I ')I I .- N

FREUECY , HF 31 S At o Fqn R nclun R t C n F le r c

"::::~:" ii ..... ]1.H

'1 1- NOM K ,7 I * ,c . .

,.,,, ,,,t~ it .! i i j i i ,,, ,r ... .. ..

,I; . .,1 ti I ....$1

120 1 0 " ,:I I I II, '' '* ...

.. XI4 L

SI T j:ll: 11. . .,; ...

(v -160 . -20 :";:;:"[i ' - 0 -.

. i ', : , , , ,,, if:l-r r l -i : ..,.,;. . ::

...... . , ' . 1 ... .. ...l!!i ii: .i

1 H i: i; I

ifi

T f I I !:

I! '" I :k -- -' -+ "'l " i :.I ... ..

-1 Iti ;ij; ,U ,t -- -+ - '! "...... 'i', :i,- r-t - ; ". :.F3 ........ I / i i', Ij : ' .,i i ."

0 :! .... l .'.1

FREQUENCY, HZ

Figure 3-13. Single Actuator Frequency Response, Including Rate Command Filter A

"~ "-' + r u -, u r "" i" r ° • p +Ji . " . iInlit fl 7 {Hilliff fit [Ef IT 1 I7: r :iA ; I I ii II - -4S i /1 r

1i i ifl 'ji i i+i , , t ' i H ..A

It+ ' i iII ll

! : -, . . .

t ir 11 11ii ) i , II:I i il: ii ; 1 1 -1-if* I .. ... ..i ~~ ~ !i I II~lt ]I i ..... i: : ...

(.0: 1.1 fl11 t .

0 20 , j "

. W ! I

i II i! , : T - 1 Icl ... ........ • -id~ - .. 4.i1}I*fi Llt NO 1.

!l "+ ; ' -" -0 .

-10 I0 : i II C - i -

L if ' 2xRT AN I~IiIj : ~ i:;:i~lili NM. ATENOM. Kii

fill 11: Itl 0l -FILTE......R;.

Figr -. S l A o F c R e I n at e C n Fr B10 V T 1;

dil!

il I I I I ....

. ... mI ! " h, i. , ,i ," " ... ' .+"

..I iII ' " Il i + .... ..

K 0

.. . II Il Jm iiT ~~I "I I/; ji: ,," "

"+ '< fif11 . /ti ;it "'I [l , NOM -,4i :

IV:

'!it t; i!' :]:; :li -

10. 100..

I r~' 1,ii1! ifj !Ii , i r, I._.+_ . '....~~: li"i + ..,, 11, .': . .:..

, , Iti " i l ! ' ' ' "'+ i,:, ++ + l+ j ! lt, , .t :

Ii i I :i i I I I l ! II -" 0i t i: I i 1 t: ; I-160- -20 !! " . , ..• I I j +'- ' , ... :

,,.iI i i,:i -- I "" +l I " ; ii I',1 I r,11' 'i 'i -- i;+

.. .It~~~~~I ,, ,,;+ !l ....i: i i PI +. '

1. i i 10. 100..

FREQUENCY, HZ

Figure 3-14. Single Actuator Frequency Response, Including Rate Command Filter B,

02-118470-2

REPRODUCIBLITY OF THE


... .r F . r r

-- -- ,- - H-

_...

-- -H -H --. !i-7 t

i' "'

' 'L

. I"

- -- --

.-- - 7,-7 ..

.'T 100

I':: :

10004- --4-

-20

L0

.- L. ii;I I 1 4i I II I D -7 ,-,7

I -T-

1 71 L:I"

-20 4-

50

-40

-t--- F( (s/59"69)2 + 1 -0-- s)= (s/59.69)2+.0264s+1 100

I ','I P

<T C

-60 .10 .

100 .

FREQUENCY, HZ

Figure 3-15. Rate Command Notch Filter Characteristics

425'

n I I I I !;~i I ;!: I: ! F~ s (s/ 59 .69) 2 + 1 ilrl -10 0 -

-:0

7 I

-LI +ii-5

-60 ,T'!I

10. 100.l

Fi ur 3 1 . at om an ot h il e C ar c er st c

i i; f-25-

D2-118470-2

3.2.4 (Continued)

are shown in Figure 3-16. With double rate gain, actuator response is

amplified slightly at frequencies below 8 Hz and is attenuated at fre-

quencies between 8 and 18 Hz. It will be shown in Section 3.3 that the

active table has a resonance at approximately 11 Hz; therefore, filter C

should be effective in attenuating this resonance..

3.3 ACTIVE TABLE ANALYSES

Analyses of the active table were performed to determine its frequency

response characteristics and to study the ability of angle sensing limit

switches to prevent table "fall through."

3.3.1 Six-Degree-of-Freedom Motion Analysis

The six-degree-of-freedom mathematical model and computer program discussed

in Reference 1 were modified to include differential pressure feedback in

the'actuator representation. This mathematical model determines the response

of the active table to motion commands. The model includes a rigid repre-

sentation of the table structure and a flexible representation of each of

the six actuators. The actuator model also includes servo valve dynamics,

hydraulic flow and pressure equations, and the electronic control system.

The math model and computer program, NASA Advanced Docking System (NADS),

are described in detail in References 2 and 3, respectively. The actuator

-parameters determined from the single-axis actuator analysis were used in

NADS to obtain active table frequency response data and to assess three-

dimensional coupling effects.

Two attempts were made to obtain table frequency-response testdata to

compare with the analytical predictions. The first frequency response test

was performed using five cycles of table position and velocity command at

each frequency. The command was limited to five cycles at .125 inch to

minimize the dynamic environment on the linear potentiometers. Discrete

-26-

l 1 ! ! 1I . . i 1 "0 i .- . !ill ; : I ...! 1 I .. . . .il --- ; ' ,. . :" i '

tl .. I :I f II II [' ' i, t; Iiri . . ............ ',i i i i t . .. ;l LI i

.... ~~il il II "i f t i ,, ii. .It I .. .lli ; I I ... ...... I :i I 1! -' I t;:i i i fI t -I I ' " ,. : I:

-4020 ... -, ,, la ' " ' .... ''i "

:h : il j :if .. .. .ill, l ~~~~i cll iI. lN..i :: .. ,' ,, " i i i I i -11iii i i : 'I i f l . I : . :.. .

':II'.II!I:: II II ' :C j : ~i :i,, .. . II H I N , i!,I .

J.. ...U 1C4 mI i , ii i I Iii .... ... .III II .. ......I : .. i .

,~~~~~~~~~ u ii,.,,:1 -... ... uNOM Kti ,.,, , rc

Ii., ! ' , T I1 t. -- - -I

i l I ll I"i DO B E R T A N- -: i::,

IT i:

,, ... ,/l : ... 1

-T - I It I i 1 ,

-120 -0 !: I , i 11 .

,,i j iii ii,,,,,, :: -. . iji: I

"- 01 1 10. ' l

ci ur rll: l120 I i iH I I:

0 •1i00.

~FREQUENCY, HZ.Figure 3-16. Single Actuator Frequency Response, Including Rate Command Filter C

D2-118470-2

3.3.1 (Continued)

frequencies were used due to the need for both position and velocity

command signals. The tests in all axes were curtailed due to excessive

table response at frequencies in the vicinity of 10 Hz. The severity of

the starting transient at each frequency was considered to be the cause of

the excessive dynamic response. There was also considerable drift in the

sinusoidal command signal.

A second table frequency response test was attempted with a reduced input

command signal. This test used a. 0.05 inch sinusoidal position command

signal in each of the X, Y and Z directions. The velocity command

gain, Krc, was set to zero. This permitted the use of the automatic

frequency sweeping signal generator. The frequency sweep was begun at

1.0 Hz and incremented by 1.0 Hz after 15 cycles at each frequency.

Using the actuator parameters listed in Table 3-1, frequency response

characteristics of the table for position commands in the X, Y and Z

directions were obtained using NADS computer program. The table frequency

response exhibits two resonances--one at the hydraulic resonance (% 30 Hz)

and another which corresponds to the bending frequency of the actuators

(' 11 Hz). In the lateral directions, the hydraulic resonance occurs at

22 Hz due to increased effective mass in the lateral direction. Table

and actuator acceleration response predictions were also obtained. Based

on these predictions, a table acceleration limit of ±3.0 g was established

to preclude possible damage to the table or actuators. Accelerometers on

the table and actuator 6 were monitored during the test, and an automatic

abort capability was utilized.

Each of the tests was aborted automatically due to excessive accelerations

at 9 Hz in the lateral direction and 11 Hz in the vertical direction. Com-

parisons of predicted and experimentally derived table displacements are

shown in Figure 3-17. Predicted table accelerations are compared with

measured table accelerations in Figure 3-18. Lateral accelerations measured

at the upper end of the actuator 6 cylinder are compared with pretest pre-

dictions in Figure 3-19.

-28-

D2-118470-2 REPRODUCIBILITY OF THEORIGINAL PAGE IS POOR

10

o - I

--i

10

F-10d

-20

1. 5. 10. 50.

FREQUENCY, HZ

S-29-

t J--20

10 ...........

i 2 1 t t 1 11- - I- -- b-

- -- -- I - -- --- "

.-29-

D2-118470-2

REPRODUCIBILITY OF THEORIGINAL PAGE. IS POOR.

10.

AI ~~ ~ - 7-T tH ,11

~liilili i: i!ilr:~

I~il~ ' ;;l :

', 11: I-H

I 0-II Ii IMM1H H i H i .+l IIN I !iii

J. J i-:-I H H :

dF

tFE N HHZ -Irtiti"'r

Figure 41. Tl A

till--

C:)

L i i

ITE

L-i j!

_ tiltL -l- -i 4-.- . :P l Ti1-tH~;

- 7III.LUI-U _L~IL~-I~L~liL.l11 1 M M ER&IF

# S Hll A ILl-cUN N4I#t'?i nl l TX -r fT ~f ~ ft~ltff~~l- ;

!1 7 : ;ai ~1~--:----':1 tt/.Litt= ;'if 'z~:~l-~t~:;" :CTrl::IN:11 i ~ =2;:4 7

4 6 7 8 9 10. 175 2 2.5 3 5 6 7 8 9100.

FREQUENCY, HZ

Figure 3-18. Table Accelerations, Frequency Response Test

-30-

D2-118470-2

10.i - l

! il '1 I 11:4 -41 1 1I .1 i.' i '

.014 : -- ill: i O J

I ii i iii ill Ji i I

:Jt:

i Ii:i: 1.i ,i .;, !:j1 , I.I- j ' I 1 _kb 4Th T4l. i1 4FihF471 -1 1 11 ii! I

i 21 fj 17 -1-# ilj Vi A .1

LUVi ll H i _9_ 71 !

,I i ii - Ii,0igr 3-19l L1t io F u R Tet

n-i31

4H 4 1-

I i jit

-- 4

s~tfl~ L AlI't i24 5i !~:'H i~ Y : #; : im qi i-i~i

I- i

5+ 4 + i .15 2 2.

F U HZ

-4 E f i ziili !

U Ti

Figue 3

-31-IV

141TH 1TH

'i -I- 4 "rl f-L

T+-:;+ + iin !

tt~/- H I.

ti li ~!~tLcr ;1J

:.;;;,.... i ,, -31 -:

D2-118470-2

3.3.1 (Continued)

It is apparent that the active table exhibits considerably higher dynami6

characteristics than were predicted; however, the cause of this discrepancy

has not been identified. Reducing the damping associated with actuator

flexibility did not increase analytical table response significantly.

Analysis of the analytical frequency response predictions shows that

insignificant coupling between table responses in the commanded direction

and responses in other directions exists. During the frequency response

test, however, some coupling was observed. In general, the off-axis motion

was less than 30 percent of the commanded table motion at frequencies below

10 Hz. The highest coupling occurred during the X-axis test at frequencies

of 10 and 11 Hz (the test was aborted at 11 Hz). Detailed frequency response

test results are documented in Reference 4.

3.3.2 Angle Abort Limit Analysis

Four angle sensors were installed at the upper swivel of each actuator.

Each sensor consisted of a fixed "microswitch" with a roller-leaf actuating

lever bearing on a rotating pilot disc having adjustable cams. The cams

were designed to actuate the switches for both clockwise and counterclockwise

rotation. These four switches, designated A, B, C, and D, were situated so

that switches A and B measured rotations in a vertical plane while switches

C and D indicated rotations-predominantly in a horizontal plane (see

'Figure 3-20). A swivel angle limit abort plan was developed to utilize

these switches to prevent damage to the simulator and docking hardware due

to table "fall through" and to limit the horizontal envelope of the table

motion within the environmental enclosure. "Fall through" is a term used

to refer to a condition that is possible because of the relationship between

table and actuator geometry. If the table becomes rotated to the point

that it is in a plane with adjacent pairs of actuators joining at a table

corner, no vertical support is provided by these actuators; thus, permitting

this corner of the table to travel vertically as the two actuators rotate

about their base.

-32-

rALE

" PLOTCA W

SBCRADLE/

VIE X-X CRADLE/TALE TNGLES

TYPICAL OF ATUTOrS1 3 AD5

ACTUATORICRADLE AN rr LESC rU.Rro , ' 5i:e. ,rC- 'A' R!- G S'A

TYPICAL OF #CT4ATMRS 1, 3 AND C 7 WPd :T F7Ao TOLE).(ACTUAITS 2, 4 AANDj 6 MIRROR IAMCE-

.C. ,wTC"C~CCST 7~ CtNT.r -,Ad - SWITCubDEurARD)

Figure 320. Angle Limit Abort Switch

Figure 3-20. Angle Limit Abort Switch

D2-118470-2

3.3.2 (Continued)

The angle setting for which .these cams must be set in order to satisfy the

objectives can be determined once the relationship between table transla-

tion and rotation and sensor rotations is known.

Let Ap define the "horizontal" angle change measured with switches C and

D when the table moves; let AB be the "vertical" angle change associated

with switches A and B. Define p and Bj as the angle measured in the

plane of the switches of actuator- j as follows

j = tan-1 x + z,

-Yj

-1 j3S= tan 1 JJ z.

Where xj, yj and zj are actuator lengths as defined isometrically in

Figure 3-21 for j = 2.

To determine the value of pj and Bj for all actuators and all locations

of the table, define the following parameters:

[RA] = A 3 x 6 matrix of table coordinates at the upper end of theactuator

[RF] = A 3 x 6 matrix of inertial coordinates of the actuator floorattach points

x

YI = Inertial position of table c.g.

z

} = Euler angles

-34-

.Y

5 6

TABLE

4 --- ACTUATOR NO. 1

3 2

TABLE SWIVEL JOINT / X

/

Y. X2+ Z2ejI

X j , , ACTUATOR NO. 2

' FLOOR SWIVEL JOINT

Figure 3-21. Table Coordinate System and Definitionof Actuator Lengths

-35-

D2-118470-2

3.3.2 (Continued)

The 3 x 6 matrix of floor attachment locations expressed in table coordinates

[RFT], is given by

x

[RFT] = IA] T IRF] Y L1 i 1 1 1 1]

and the 3 x 6 matrix of components of actuator length in table coordinates

is given by

[ALT] = IRFT] - IRA]

The values of the xj, yj and zj are then defined by the use of geometry as

x. = ALT(1,j)

Yl = ALT(3,1)*.86603+ALT(2,1)*.5

Y2 = -ALT(2,2)

Y3 = -ALT(2,3)

y4 =-ALT(3,4)*.86603+ALT(2,4)*.5

Y5 = -ALT(3,5)*.86603+ALT(2,5)*.5

y6 = ALT(3,6)*.86603+ALT(2,6)*.5

z1 = -ALT(2,1)*.86603+ALT(3,1)*.5

z2 = ALT(3,2)

z3 = -ALT(3,3)

z4 = -ALT(2,4)*.86603-ALT(3,4)*.5

z5 = ALT(2,5)*.86603+ALT(3,5)*.5

z6 = ALT(2,6)*.86603-ALT(3,6)*.5

-36-

D2-118470-2

3.3.2 (Continued)

A listing of the computer program, TABGEOM, developed to perform the

calculations is reproduced in Figure 3-22. The values of the constants,

[RA] and [RF] used in the analysis are shown in Table 3-2 and Table

3-3, respectively.

Analyses were performed for several table heights with various combinations

of translations and rotations to establish limit switch settings that would

satisfy the original objectives. The resulting recommended limit switch

settings to prevent table "fall through" are shown in Figures 3-23 and 3-24.

Implementation of the limit switches for the constraint of lateral motion

was found to be impractical since large lateral motion which results from

small angle changes could not be controlled accurately enough with the

setting fidelity of the angular readings available on the switches; and

because unlimited translation could occur with the proper combination of

table rotation. For example, unlimited -Y translation can be obtained if

a + rotation about the Z axis is added continually so that no change in

the indicated angle on the limit switch occurs with Y translation. There-

fore, the system did not provide a "foolproof" abort system for lateral

table motion.

The lateral constraint desired was obtained by implementing computer aborts

that sensed motion outside of a specified conical frustrum within the

environmental enclosure; thus, satisfying the original objective of no

interference with the environmental enclosure. The conical, frustrum

required to satisfy the abort objectives is defined by the following

coordinates:

At table height, X = 70.4 in. the abort radius is 38.5 in.

At table height, X = 159.461 in. the abort radius is 28.6 in.

-37-

D2-118470-.2

REPRODUCIBILITY OF THEORIGINAL PAGE IS POOR

C:F' TABGEOM FORFTRA

DIMENSION RA ::::, 6: , F.RF ,:',. 6> :A (,: ::) , PFT (3 6) .1ALT (3, 6.: s FtL (6, Y ,(6> :) ,:>: : BETA.<6) ., RHO (6. .'2 THETA (6 :' sRS (3 . 6) :: YZ ( 3 ::

DATA R A .. 5.1. 02,49.5 . -55.419,3 O. 0.-55.419 -3.,1 0. 5.10: -49.5 0. :30.29 -46.5 0. :30.29, 46.5 ....

D 1T A RF- 210.407, -64.311 123. 178 210:. 429, -76. 38::, 116. 124,1 21F0.422 -74.573, -116. 819,210.417 -62.412 -123.683::,

2 210.410,138.463,-5.9752 ' 10.369,138.389,8.00510 REHAD 59 1 END=100 I ERR=100 (XY (Ii :: I :: I = 3 :: ,THTA F:S I F'HI

THTA=THTA.57. 2578FH I =HI . 55 . 7P I =P I57.295 7CT=COS(THTrCS=COS : 0: :: F' : I :CPF' = : P: HI::T=S IN(THTA:

SS = :: I H ,:: F' " I :

A P=:: IN = HI::

A , 1:, =-:- T C::

A ::: , =-P) C

A ::, : =-ST : :: F'

C CALCULATE ACTUATOR FLOOR ATTACHMENT LOCATIONS INC TABILE CDORDINATES

DO 20 I=1 3DO 20 I =l,RFT':IJ)=0.DO 20 K=1:3

2 0 RFT : I =FT(I - T '( I, .1: +A '1<:, I : :(RF (K::K .1:) -::: Y Z (: :C COMPONENTS OF A:CTIIATOR LENGTH:S IN TABLE C:OORDINATESDO 30 I=1:3DO :0: ._J=06

30 ALT (I , =RFT I::I, ._: -PA (I 1J:C CALC:ULATE ACTUIATOR LENGTH:

DO 50 I=16AL (I:: = I.DO[ 40 _1=1,:

4 0 AL(: , =AL (I :: +ALT (::j.I ) *ALT ( I::51:10 L I : =:S RT AL (I ::'/

Figure 3-22. TABGEOM Listing

-38-

D2-118470-2



I : =-AL T : 2 :

Y(4:=-RLT(3 4 .86603+LT 2!154::I

i 1 r.

Y: 4:' =- A L T ,:: : : 4) *. 8,q66 0 :- + RLT (2, 0 4 , a. 5Y(5: =-RLT( ,5 *.8663+ALT. ,5::: *.5

Y(6:=ALT(2 6::* .6603+ALT'(2,6::*.5

TA :: =-ALT ::,1 T : .66 3+ALT ,1 .5

Z H(5:: =AL T (2,5::T ALT . 1 663+ LTZ (6): =ALT (2, 6).66 03-ALT (3,6::. 5DO 60 I=0;6BETA :::=AT N(ALT(1 . Z::* I::':RHO I::=ATAN(SORT,::ALT(1,::I'*2+Z:::1.**2::./( . :,:BE:TA ( ::' =BETA ::::' *57.2957:8

60 RHO : 1=R HO I:: 57.2957'5DO SO I=13DO 10 .1=16r i:: I J:, = 0.

DO 70 K=1I,370 RS: ,: .I : = RS:: (IK J:, +A (:1: K) :: RA K9::: , J::

:: ,: I :: = RS ( I . : - RF (I j:: + -YZ ,:DO 90' I=1: 6THETA(I ::=ATANH (R' S(1 l .I::SQRT :(RS(2,:: I **2+RS (3 1::,**2:::,

90 THETAI :: =THETA:: I 57.2957:90 1 F .ORMAT ::6E12.6 ::,902 FORMAT':.1 : A (T15, 3E 15.6 .:,

..IRITE (6, 903: AL903 :- FORMAT ::. 10 l::.::. ACTIATOR LENG THS: , (T26, :3E 15. ::

!WR ITE (6, 904) ( i RHO(I: 1 ,BETA :: ( ,THETA r (I: =1, 6'::

9 04 FORMiAT ,:1 0I::. -HO, E:ETA, THETA FOR AC:TUATOR/: : (1 l:.I: I5, :3:E 15. 6::905 FORMAT . 1 ::: " FR.: (Ti 5 3E1, 5. 6 ::.

GO0 TO 1I0100: :STOF'

Figure 3-22. TABGEOM Listing (continued)

-39-

D2-118470-2

TABLE 3-2

FLOOR SWIVEL JOINT LOCATIONS*

ACTUATORNo. x f' (in.) .. yf (in.) zf (in.)

1 210.407 - 64.311 123.178

2 210.429 - 76.380 116.124

3 210.422 - 74.573 -116.819

4 210.417 - 62.412 -123.683

5 210.410 138.463 - 5.975

6 210.369 138.389 8.005

*(Center of lower swivel axes referenced to theDOTS load cell pair axes intersections, measured)

TABLE 3-3

ACTIVE TABLE SWIVEL JOINT LOCATIONS*

ACTUATOR x (in.) y (in.) Z (in.)No. a a a

1 0.0 25.102 49.500

2 0.0 -55.419 3.000

3 0.0 -55.419 - 3.000

4 0.0 25.102 -49..500

5 0.0 30.298 -46.500

6 0.0 30.298 46.500

*(Body 2 coordinates of top swivel joints, fromdrawing)

-40-

D2-118470-2REPRODUCIBILITY OF THEORIGINAL PA E IS POOR

16.50

SWITCH A

12.50 SWITCH 8

" TABLE

Note: Valid only when tableCG is located at

cW X=137.288, Y=O, Z=0.

Figure 3-23. Limit Switch Setting to preventTable Fall Through, Actuator 1,3 and 5

~0TABLE 165 SWITCH A

SWITCH B 12.50

CW Note: Valid only when tableCG is located atX=137.288, Y=O, Z=O.

Figure 3-24. Limit Switch Setting to PreventTable Fall Through, Actuator 2,4 and 6

-41-

D2-118470-2

3.4 TOTAL SYSTEM STABILITY ANALYSIS

Math models were developed for each of the components in the total DDTS r

(Figure 3-25) from test or analysis to assess total loop stability. Each

component will be discussed separately in the following paragraphs. Due

to the complexity of the simulation, only X-axis stability was investigated.

3.4.1 Load Cells

Relative motion between the two simulated spacecraft results in interaction

forces which are measured by the six load cells in the stationary portion

of the simulatcr. The dynamic load measuring capability of the load cell

system was assumed to be characterized by a first order transfer function:

FLC 1LC FDH S/LC + 1

Where FLC is the force output of the load cells and FDH is the docking

hardware force measured by the load cells. Assuming a phase lag of 6

degrees at 20 Hz, the load cell transfer function becomes:

LC S/1257. + 1

3.4.2 Transmission Lines

The transmission lines carry the load cell voltages from the simulator in

Building 13 to the hybrid computer in Building 16 and also the actuator

commands from the computer to the simulator. Tests performed on the

-42-

D2-118470-2

BUILDING 13 BUILDING 16

LOAD CELLS TRANSMISSIONLOAD CELLSLINES

TLC

TTL

DOCKING I HYBRID

HARDWARE COMPUTER

TDH I THC

ACTIVE TABLE TRANSMISSION

& ACTUATORS LINES

TT TTL

Figure 3-25. Total System Block Diagram

-43-

D2-118470-2

3.4.2 (Continued)

transmission lines showed very low noise levels and negligible phase shift

in the dynamic range of the DDTS. Therefore, a unity transfer function

was assumed for the transmission lines.

3.4.3 Hybrid Computer

The load cell voltages received by the hybrid computer are converted to

total interaction forces between the spacecraft. The relative motion of

the spacecraft is calculated in the computer by integrating the equations

of motion under the influence of these forces. The relative motions are

then transformed into DDTS hydraulic actuator position and rate commands.

A frequency response test of the hybrid computer was performed by inputting

a sinusoidal voltage representing a force in the X-direction. The actuator

commands generated by the computer were displayed on an oscilloscope and

photographed. It was found that the wave form of the relative motions cal-

culated began to be distorted at frequencies above 8 Hz. This distortion

is caused by limitations of the TRICE, a real-time digital computer used to

integrate the translational equations of motion. The TRICE is configured

to provide very precise calculation of relative translational positions

which are required to insure that proper docking initial conditions are

obtained. This, however, results in reduced dynamic capability.

These test data show that the computer phase shift on commanded actuator

length is approximately -8.6 degrees at 8 Hz. Assuming that this lag can

be simulated as a first order lag filter, the hybrid computer transfer

function is:

C _ KHCHC FLC iS2 (S/wHC + 1)

-44-

D2-118470-2

3.4.3 (Continued)

where kC is the commanded actuator length,. FLC is the force output of

the load cells, and KHC is a constant which reflects the mass associated

with the simplified X-axis translation equation and the transformation

between relative body motion and actuator length. With a phase lag of

8.6 degrees at 8 Hz, this transfer function becomes:

.0285THC S2 (S/335. + 1)

3.4.4 Hydraulic Actuators

The transfer function for the hydraulic actuator, THA, was determined

from the single axis servo model previously described in Paragraph 3.2

Table frequency response, TT, was assumed to be similar to the single

actuator frequency response

T T P TT = TT HA A p C Anp

where AXT /AP is the change in table position due to a change in actuator

length. With the actuators at mid-stroke (the approximate position at

docking contact):

AXT' - 1.38

-45-

D2-118470-2

3.4.5 Docking Hardware

The docking hardware is the most difficult component of the DDTS to model

since docking hardware attenuators exhibit nonlinear force transmission

characteristics. Equivalent linear stiffness and damping were calculated

for various positions of the attenuators including a "full retract" case

where the two docking mechanisms are hard docked. The linearized transfer

function for the docking hardware is made up of a spring force term and

a damping force term:

FDHTDH XT KDH + KDDH S

Vaiues of stiffness, KDH, and damping, KDDH, calculated for various

conditions are tabulated below.

Condition KDH KDDH

Near full extension (compression) 6.65 .455

Full extension (tension) 1.103x10 5 167.6

Full retract (hard docked) 3.75x106 977.1

3.4.6 Stability Analysis

An open loop stability study was performed using the transfer functions

developed. The Bode plots obtained for the three docking hardware conditions

are shown in Figures 3-26 through 3-28. All cases analyzed are stable

-46-

D2-118470-2


ORIGINAL PAGE IS pOOR

K ., Fi 7 1!.! 1 ! Fi73T714 I1 -105

77: ( I :-I i :I : ., . c? S E : I :! i

2 I ... .. !

I -4

" ,, 'i , ,I~ i i : , . I ::: ; : ,:, : -- ,- ,_ ; . , .. T , . 1. I~ j

..... . - - --- ' - 4 . ... . - h-.... 44.. . . . ..... -

,41 : . :... ' .

+1 . .... ...t.. II,-H T f 1 L H -13

!]:l- .. ' ,-" ii:: .;.. .. i .. H -IA - ..1..

h" WI~ II 'L44I 2

2 - 130! . I ' i. ,I

-4-

:""( ; + - 7 .: i' ":i: i I i l .. I- , . .. .:'---

40 ~ r! 'ii-ii~-80

0.1.-q i-

•~~ ~~~~ 1 ..... ..... 2L::,L..; I' : : -r ,- i i i i :i. T --

-80 20 '' IC

Hi.

-10 L1 ii J '. N L-1 7

S. _ < 1.-

-40 :!-1-47-

,, . . ... , . : -I .. .. .-/.. . ]- - . : i .. . . . . . ... .--, - .

•i 1 i I.I0i0

FREQUENCY HZ .. i-

/i ;'-11;1; 1.. :_t.FI ! /

Figre 3 - Toal System Stbiit Nea Full Exenio

i: I H iiir -47 -'

D2-118470-2

60 -30

-40 ..I .. il-80

I T , i ' Ii

.. 130

20-0

-4 L f8

i lT

-6 . - i'4'1!l !''I 'lP1, H N & ' ji;i i' 4 130

i lll ii : Iid IIII I i Iitii

-8080

i! T5 ll

0 1 i'30

1. 10. 100. 1000.

FREQUENCY, HZ

Figure 3-27. Total System Stability, Full Extension (Tension)

-48-

Figure 3-27. ~~~~~~~~TtalSse tbltFl xeso Tnin

it -1--48 -

D2-118470-2

REPRODUCIBILITY OF THEORIGINAT, PAGE T POOR

L0 C" 14I (D60 t 30

Hi

40 -Il -80

20 -130

III j

-43FREQUENCY, HZ

Figure 3-28. Total System Stability, Full Retract

S-49-

130

UiN

-20-80

-49-

D2-118470-2

3.4.6 (Continued)

including a condition at full retract with no phase shift in the load cells

and hybrid computer. The stability.margins obtained from this study are

shown below.

Condition Gain Margin Phase Margin(DB) (DEG.)

Near full extension (compression) -67 2

Full extension (tension) -63 21

Full retract (hard docked) -26 95

Full retract (with ideal load -48 143cells and hybrid computer)

In the full retract cases, the stiffness and damping of the load cell

system was substituted for the docking hardware system stiffness.

-50-

D2-118470-2

4.0 DETAILED OPERATIONAL TEST PROCEDURES

The detailed test procedures (DTP's) for each manned operation station

used in the DDTS tests were assembled, integrated, and edited for each

major test program. The NASA Administrative Terminal System was used in

generating these procedural documents via a remote computer terminal

located in Building 13. Preliminary, review, and final copies of the DTP's

were furnished for review and approval by JSC.

4.1 PROCEDURES DOCUMENT CONTENTS

The DTP's were divided into the following six sections:

a. General Information

b. Test Procedures

c.' Test Data Sheets

d. Post-Test Verification and Acceptance

e. Test Rules

f. Emergency Procedures

The General Information section contains the introduction, test objectives,

references, abbreviations and acronyms, test configuration, communication

and test team organization, and test instrumentation necessary to perform

a complex docking test.

.The Test Procedures section contains the pretest, countdown, abort backout,

recycle, and shutdown procedural sequences necessary to operate each manned

station. These procedural sequences include the sequence number, the

commands, and the responses necessary to operate the test equipment and to

control the environment. The Test Conductor (TC) sequences contain the

main line of events for the docking tests. The Simulator Operator (SO),

Instrumentation Technician in Building 16 (IT-1), Instrumentation Techni-

cian in Building 13 (IT-2), USA Docking Simulator Operator (DS01), and the

USSR Docking Simulator Operator (DSO02) test sequences are keyed for action

into the TC sequences at the appropriate location and time.

-51-

D2-118470-2

4.1 (Continued)

The Test Data Sheets section.contains the necessary tables for recording

the data required for each docking test. The Post-Test Verification and

Acceptance section provides space for signatures of the persons responsible

for the test and its results. The Test Rules section provides the pre-

planned actions that should be performed if an off-normal condition or

malfunction occurs. In addition, the mandatory instrumentation is defined.

The Emergency Procedures section contains the recommended procedures to be

used in the event that fire or medical assistance is needed.

4.2 TEST REQUIREMENTS AND OPERATIONAL TEST PROCEDURES

Collections of test requirements (TRQ's) and DTP's were published in

References 5 through 7. The tests for which TRQ's and/or DTP's were

written are listed below along with the individual document numbers.

Reference 5 (D2-118465-1)

Hybrid Computer Subsystem Test, TRQ-1-13/16-73

Hydraulic Supply Subsystem Test, TRQ-2-13-73

Electrical/Electronic Subsystem Test, TRQ-3-13-73

Load Cell Subsystem Test, TRQ-4-13-73

Transmission Line Subsystem Test, TRQ-5-13/16-73

Data Acquisition Subsystem Test, TRQ-6-13/16-73

Servo Actuator Unit Test, TRQ-7-13-73

Data Reduction Verification Test, TRQ-8-13/16-73

Motion Simulator Test, TRQ-9-13-73

Gravity Compensation Subsystem Test, TRQ-10-13-73

Thermal Environment Subsystem Test, TRQ-11-13-73

Hybrid Computer Subsystem Test, DTP-1-13/16-73

Hydraulic Supply Subsystem Test, DTP-2-13-73

-52-

D2-118470-2

4.2 (Continued)

Electrical/Electronic Subsystem Test, DTP-3-13-73

Part I, Instrumentation

Part II, Force Measuring System

Part III, Comcor Line Driver Checkout

Part IV, Simulator Control Panel..

Part.V, Servo Amplifier and Abort Card Test

Part VI, Analog Computer Checkout (AD-80)

Part VII, Local Computer Control Checkout

Part VIII, Interface Verification

Part IX, Differential Measuring System

Part X, Electronic System Checkout.

Load Cell Subsystem Test, DTP-4-13-73

Load Cell Subsystem Test, DTP-4-13-73 (Rev. A)

Transmission Line Subsystem Test, DTP-5-13/16-73

Data Acquisition Subsystem Test, DTP-6-13/16-73

Servo Actuator UnitTest, DTP-7-13-73

Data Reduction Verification Test, DTP-8-13/16-73

Motion Simulator Test, DTP-9-13-73

Gravity Compensation Subsystem Test, DTP-10-13-73

Thermal Environment Subsystem Test, DTP-11-13-73


Hydraulic Supply Subsystem Test, DTP-2-13-73, Rev. A

Electrical/Electronic Subsystem Test, DTP-3-13-73

Part VI, Analog Computer Checkout (AD-80)

Part IX, Pressure Abort System Verification

-53-

D2-118470-2

4.2 (Continued)

Servo Actuator Unit Test, DTP-7-13-73, Rev. A

Motion Simulator Test, DTP-9-13-73

Gravity Compensation Subsystem Test, DTP-10-13-73

Thermal Environmental Subsystem Test, DTP-11-13-73

Probe and Drogue Test, DTP-12-13-73

DDTS Integration and Open Loop Test, DTP-14-13-73

USA Development Test, TOP-2-13-73


USA/USSR Joint Dynamic Development Test, TOP, USA WG3-009

USA/USSR Joint Dynamic Development Test,-TOP, USA WG3-009A, Rev. A

USA/USSR Joint Dynamic Development Test, TOP, USA WG3-009B, Rev. B

Verification of Docking System Kinematic Envelopes on the DynamicDocking Test System, TOP USA WG3-012

USA/USSR Joint Dynamic Qualification Test, TOP, USA WG3-020, Review Copy

-54-

02-118470-2

5.0 ANALYSIS OF DOCKING DYNAMICS AND LOADS

This section discusses the results of the US/US development tests, the US/

USSR development tests, and the 10 Hz investigation conducted to evaluate

proposed "fixes" to the 10 Hz anomaly that arose during the development

tests. The subsequent US/US qualification testing performed using these

fixes is also discussed.

5.1 DEVELOPMENT TESTS

The development test program was conducted to "prove that the USA and USSR

docking system can withstand the maximum loads and perform all required

functions under design conditions" (Reference 8). The DDTS served as the

instrument to provide this proof. The function of the DDTS was to:

a.' Provide the desired relative docking initial conditions to the docking

hardware.

b. Simulate the subsequent relative dynamic motion of the two spacecraft.

c. Supply as output

(1) Design hardware loads

(2) Capture characteristics

Items b and c were also obtained analytically. Results from the two sources -

test and analysis - were then compared and an assessment made.

The following assessment of the US/US and the US/USSR development tests can

be made:

a. Desired initial contact conditions were achieved with a high degree of

accuracy.

b. Good correlation between analytically predicted capture and experimental

results was obtained.

-55-

D2-118470-2

5.1 (Continued)

c. Good agreement was obtained between analytical and experimental load

and motion signatures (especially during the time span from contact

through capture and maximum loads).

d. In general, peak loads were within 10 percent of analytically predicted

results.

5.1.1 US/US Development Tests

This series of tests was conducted prior to the joint US/USSR development

test. The test article consisted of the active US docking hardware on one

side of the DDTS and the passive US docking system on the other. The simu-

lation was modeled so that the mass properties of the US passive system

represented the Soyuz mass properties. This series of tests, then, simulated

the joint US/USSR tests to be conducted later with the USSR passive system.

For this reason, a detailed presentation of US/US development test data

and analysis results is not included as part of this report. Only a summary

is presented.

Tests were conducted with the initial docking contact conditions shown in

Table 5-1. Only ambient temperature tests were performed and cases 7, 8,

11 and 12 were omitted. The test data obtained are documented on microfilm

and can be obtained from Reference 9.

5.1.2 US/USSR Development Tests

Joint US/USSR development tests were performed with both the USA and the

USSR docking hardware in.the active mode. The discussion of test results

that follows, however, will be primarily devoted to tests conducted with

the USA system active since no OSSR active system analytical results are

available for comparison purposes.

-56-

D2-118470-2


TABLE 5-1 US/US DEVELOPMENT TEST CONDITIONS

'CLOSING 3LATERAL 4MISS nANGULAR RATE (ANGULARVELOCITY VELOCITY DISTANCE Roll Pitch Yaw ATTITUDE TEMP REMARKS

CASE X Y Ym Zm (deg/ (deg/ (dog/ Roll Pitch Yaw(mps(fpsl nips) s)(mps) (fps) (m) (ft) Jm (ft) sec) sgj _ de___d__)__f. 5 ........ e "b Straight-in

1 .05 .164 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 amb Straiht-inlow energy

2 .0915 .3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 nominal

Straight-in3 .3 .985 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 hrigh e in

4 .05 .164 -.05 -. 164 0.0 0.0 -. 3 -. 985 0.0 0.0 0.0 -1.0 0.0 0.0 -3.0 0.0 mlowiss-Y miss

5 .0915 .3 -. 05 -. 164 0.0 0.0 -. 3 -. 985 0.0 0.0 0.0 -1.0 0.0 0.0 -3.0 0.0 nominal-Y miss

6 .3 .985 -. 1 -.328 0.0 0.0 -.3 -.985 0.0 0.0 .0.0 -1.0 0.0 0.0 -7.0 0.0 -h ener

7 .05 .164 .05 .164 0.0 0.0 .3 .985 0.0 0.0 0.0 +1.0 0.0 0.0 3.0 0.0 low enrgy

8 .3 .985 .1 .328 0.0 0.0 .3 .985 0.0 .0.0 0.0 1.0 0.0 0.0 7.0 0.0 miery

-Y; -Z miss9 .05 .164 -. 05 -. 164 0.0 0.0 -. 212 -. 696 -. 212 -. 696 0.0 -1.0 0.0 0.0 -3.0 0.0 lo energymiss

-Y; -Z miss10 .3 .985 -. 1 -. 32E 0.0 0.0 -. 212 -. 696 -. 212 n.696 -1.0 -1.0 0.0 0.0 -7.0 0.0 high energy

+Z miss11 .05 .164 0.0 0.0 .05 .164 0.0 0.0 .3 .985 -. 5 0.0 -1.C 0.0 0.0 -3.0 low eneroy

12 .3 .985 0.0 0.0 .1 .328 0.0 0.0 .3 .985 -1.0 0.0 -1. 0.0 0.0 -7.0 + emisshihenerh

13 .05 .164 -.025 -. 080 -.05 -.164 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -.3 .6 Pitch-y w miss1 11 low energy

14 .05 .164 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -.5 0.0 0.0 -7.0 0.0 0.0 Roll missRol miss

15 .0915 .3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -1.0 0.0 0.0 -7.0 0.0 0.0 nominal

16 .3 .985 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -1.0 0.0 0.0 -7.0 0.0 0.0 Rh energy

17 .05 .164 -. 05 -. 164 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 7.0 0.0 Jack knifelow enerey

18 .0915 .3 -. 05 -. 164 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 7.0 0.0 Jack knife8 .3__ I . nominal

.19 .3 .985 -.1 -. 32 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 7.0 0.0 amb Jack knifehlh energy

! The spacecraft with the active and passivedocking systems are designated as body 1 andbody 2, respectively.

2 Spacecraft control system operations aredefined in IED50016.

3 Closin and Lateral Velocities (X, Y, Z)Tra atical velocity components (expressed -in the body 2 system) of the body 1 c.g.with respect to the body 2 c.g. ACTIVE USA

SCING IYSTEMSMiss Distance (Ym, Znm)

Coordinates(exprssecd in the body 2 system) (-7 ).+Z A5

of the point 'defined by the intersection of AS 1 +Y (AS: AXISthe X axis and the plane passing through TIOUCH GUIDEthe forwardmost part of the body 1 docking . CEIT ERLINE)system guides. BODY 1

S Anoular Rates (Roll, Pitch, Yaw)Relative rotational velocity components ofbody 1 relative to body 2 (expressed in the +Xbody 1 system) using the right-hand rule for 1direction of rotations about the X1 , Z1, andY1 axes, respectively. (ZC52)+ PITCH YAW Y2(+YC5

£ Ancular Atti.tude (Roll, Pitch, Yaw)Roll attitude is the included angle (meas- BODY 2 -.ured in the Y-Z plane of the body 2 system) ,PASSIVE USSRfrom the X-Y plane of body 2 to the X-Y DOCKING SYSTEMplane of body 1, using the right-hand rulefor direction of rotation about the X2 axis. NIOTE: COORDINATEPitch and yaw attitudes are the components SYSTE:,INI,' PAREITESESof the included angle (expressed in the body CORRELATES SIULATOR2 system) from the body 2 X-axis to the body T. AXIS SYSTE: WITHS S/C

1 X-axis, using the right-hand rule for ROLL AXIS SYSTEMpitch attitude about the Z2 axis and yawattitude about the Y2 axis. +X2

-57-

D2-118470-2

5.1.2 (Continued)

Test cases used in the joint.development test are shown in Table 5-2.

These conditions were chosen to demonstrate docking capability at various

temperatures (ambient, high, and low). Some cases represent high energy

cases chosen to produce design docking hardware loads, and other cases are

low energy cases which could lead to capture difficulties. The test data

obtained with the USA system as the active spacecraft are documented in

Reference 10; the USSR active test data are in Reference 11. Since these

test reports consist of 14 volumes and 35 volumes of data, respectively,

the tables of contents are included in this report as Tables 5-3 and 5-4

so that specific data might be found more easily.

As mentioned in Paragraph 5.1, the test results obtained with the USA

docking hardware in the active mode agreed closely with the pretest

analytical results obtained with the JSC "Ring Finger Docking Dynamics

Program." Test versus analysis correlation results for each test case

are documented in Reference 12. Some typical plots from Reference 12 are

shown in Figures 5-1 through 5-6. A summary of the comparison of peak

loads obtained in the high energy cases is tabulated in Table 5-5.

Figures 5-1 through 5-6 demonstrate the good agreement that was obtained

for two high energy cases shown in Table 5-2. Also indicated in these

figures is a 9-10 Hz dynamic phenomenon that is not considered to be repre-

sentative of the docking hardware. These oscillations can be classified as:

a. 10 Hz oscillations

b. 10 Hz instability following capture

These phenomena were observed in test results w.ith either the USA or the

USSR docking system in the active mode.

The general 10 Hz oscillation was present in most test runs. However, it

was usually of such low amplitude that it presented no major concern. In

some cases, the 10 Hz content was large enough to cause questions to be

-58-

D2-118470-2


TABLE 5-2 US/USSR DEVELOPMENT TEST CONDITIONS

3CLOSING 3LATERAL "MI1SS

5ANGULAR RATE GANGULAR ATTITUDE

VELOCITY VELCITY DISTANCE Roll Pitch Yaw Roll Pitch Yaw TEMPERATURE REMARKSCASE X Y Z Ym Zm (deg/ (deg/ (deg/... mp____ps (m) (m) sec] sc) sec_ d) d.) d

Straight-in1 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 high, low high energy

-Y miss,2 0.3 -0.1 0.0 -003 0.0 0.0 -1.0 0.0 0.0 -7.0 0.0 high, low hi ergy

3 0.3 0.0 0.1 0.0 0.3 -1.0 0.0 -1.0 0.0 *0.0 -7.0 high, low mhiess

4 0.3 -0.1 0.0 -.212 -.212 -1.0 -1.0 0.0 0.0 -7.0 0.0 high, low hih iss

5 0.05 -0.05 0.0 -0.3 0.0 0.0 -1.0 0.0 0.0 -3.0 0.0 low miss,

6 0.05 -0.05 0.0 -.212 -.212 -1.0 -1.0 0.0 0.0 -3.0 0.0 low -Y; - miss,

+Z miss,7 0.05 0.0 0.05 0.0 0.3 0.0 0.0 -1.0 0.0 0.0 -3.0 low iow energy

Roll miss,8 0.05 0.0 0.0 0.0 0.0 -1.0 0.0 0.0 -7.0 0.0 0.0 low low enery

Max Soyuz9 0.3 -0.1 0.0 -0.3 0.0 0.0 -1.0 0.0 0.0 7.0 0.0 high, low ide load

10 0.3 0.0 0.0 0.0 0.0 1.0 0.0 0.0 7.0 0.0 0.0 high, low hi energy

11 0.05 -0.05 0.0 -0.3 0.0 0.0 -1.0 0.0 0.0 7.0 0.0 low -Y, Max. Ang. Miss,low energy

12 0.05 -0.05 0.0 -0.3 0.0 -1.0 -1.0 0.0 -7.0 7.0 0.0 low Y, Max14 Ang. Miss,_ _ __roll, low energy

1 The spacecraft with the active and passivedocking systems are designated as body 1 andbody 2, respectively.


Closinr and Lateral Velocities (X, Y, Z) )Translaticnal velocity co-mponents (expressedin the body 2 system) of the body 1 c.g.with respect to the body 2 c.g. ACTIE USA

Miss Distance (Ym, Zm) -'... .scr"-G SCoordinates Texpressed in the body 2 system) ( ) +Zof the point defined by the intersection of AS 1 +Y1YA5: AXISthe X axis and the plane passing through TIROUG H GUIDEthe or-,ardmiost part of the body 1 docking CTERLII'E)system guides. .BODY 1

5 Ancular Rates (Roll, Pitch, Yaw) 6" M .Relative rotational velocity components ofbody 1 relative to body 2 (expressed in the +Xbody 1 system) using the right-hand rule fordirection of rotations about the Xi, Z1, and (+YY1 axes, respectively. (-ZC z PITC \ YA Y2 T

'

C An,:ular Attitude (Roll, Pitch, Yaw) 4- - --Roll attitude is the included angle (meas- .BODY2 -ured in the Y-Z plane of the body 2 system) PASSIVE USSRfrom the X-Y plane of body 2 to the X-Y, ./ \ DOCIN; G SYS1EMplane of body 1, using the right-hand rulefor direction of rotation about the X2 axis.INOTE:COORDI:ATEPitch and yaw attitudes are the comlpnIents Ss'E;1 I1 JPAI:.!:ITESof the included angle (expressed in the body .s CORRELATES SILULATOR2 system) from the body 2 X-axis to the body AXIS SYSTE:.' WIT I S/C1 X-axis, using the right-hand rule for IROLL AXIS SYSTEI.pitch attitude about the Z2 axis 'and yawattitude about the Y2 axis. +X2

-59-

02-118470-2

TABLE 5-3

LOCATION OF DOCUMENTED TEST DATA

US/USSR DEVELOPMENT TEST - US ACTIVE

TEST

VOLUME TEST CASE TEMPERATURE IDENTIFICATION

Category I

1 5 ambient 101931400051

2 6 " 101931400061

3 1 cold 103031600011

3 2 " 110231600021

4 3 " 110231600031

4 4 " .1102316000424 5 " 102931600051

5 6 " 1029316000616 7 " 110231600071

6 8 " 110231600081

7 9 " 110231600091

7 10 " 1102316001028 11 " 102931600111

8 12 " 1030316001219 1 hot 1026315000119 2 ' " 120731500021

9 3 " 10263150003110 4 120731500041

11 9 " 10263150009111 10 " 102631500101

Category II

12 3 ambient 120631400031

12 9 " 120631400091

13 10. " 120631400101

13 11 (SCS + retract) 120631410011

14 3 (DAP) 120731410031

14 9 (DAP) 120731410091

14 10 (DAP) 120731410101

14 1 (DAP + retract) 120731410011

2 hot 1207315000414 120731500021

> Volume number of Document USA WG3-018.

> Included in the Category I listing above.

-60-

D2-118470-2

TABLE 5-4

LOCATION OF DOCUMENTED TEST DATAUS/USSR DEVELOPMENT TEST - USSR ACTIVE

VOLUME TEST VOLUME > TEST

Category I Category II.(continued)

1 111731700051 17 112731700071111731700061 112731700081

2 111731800011 18 112731700122111731800021 112731701214

3 111731800031 19 112731700091111731800041 20 112731700911

4 111731800052 112731700611111731800061 21 112731700711111731800101 22 112731700461

5 112031900011 23 112731700621112131900012 24 112731700631112031900013 25 112831700911.112131900021 112831701221

6 112131900031 26 112831701641112131900041 112831700642112131900051 112831711221

7 112131900062 27 112831710031112131900071 112831700101

8 112031900082 28 112931700721112131900091 29 112931701111112131900101 30 112931710031112131900111 112931710092

9 112131900121 31 112931710101112931710102

Category II 32 12033190004110 112331910041 120331900411

112331910411 120331900422112331910421 33 120331900431

11 112331910432 120331900011112331910442 120331910011

12 112631700041 120331910012112631700412 34 120331900101

13 112631700421 120331910101112631700431 120331910014

14 112631700451 12033191001515 112631700111 35 12053170001116 112631701111 120531710011

112731701111 12053171010117 112731700121 120531700101

> Volume number of Document USSR WG3-022.

-61-

D2-118470-2


C12.0O C .T US-UJSSA OEVELOPMENT (US ACTIVE) HOT 102531500131

* -AyISCOrp or F E' BoY I FI1 (TF Sj TA) (A ITHEA')

±1~

S. . ...

GIJ~ ________~t~ji- 1~:ii

-r--,--r .. . . . i ii i ' I -

.4" ±h1Th

• -79 I

F __ -- - -- _

1'' { ± -. . t zi 4 ANALYSIS .... _ __..................._

c+

-Ij . -l-T-- - l Z . .:: ...

-733

... I -[ I - .. .. . . .. I .. . . . :. • '.

_ ,___ __,_ ' ' _____._

" 13.5 14 lt-,s Is 15.$ 16 16.f

Ft A Fn TIF ,5EC

Figure 5-1. Typical Test/Analysis Correlation, US-USSR DevelopmentTest, USA Active Case 3, Hot; X Force on CSM C.G.

-62-

D2-118470-2


1?.05 : C TACI US-JSSR OEVELOPMENT (US ACTlVE) HOT 102531503031

Y-AXIIC ' CV FCF C Ctf J rCY I FYI (TEST PATA) * (AT4H fl)

350 .... t ,

300

-I"

200++ -----

150

-ANALYSIS1 -i l. --. 13 13.i 14 1 .5 15 15 .

5 1 • 14

Figure 5-2. Typical Test/Analysis Correlation, US-USSRDevelopment Test, USA Active Case 3, Hot;Y Force on CSM C.G.

-63-

D2-118470-2

12.06 CcNTAT US-USSR DEVELOPMENT (US ACTIVE HOT 10263150 131

35 Z-arTS C C ~ r;'F {y 5,Tv I FI fTFST CsATAl (VTH POOL )

31

SANALYSIS

IF 1 -

250

ATTIES _

-100

15I3 * I,

12.5 1 3 13.i ( I

Figure 5-3. Typical Test/Analysis Correlation, US-USSR DevelopmentTest, USA Active Case 3, Hot; Z Force on CSM C.G.

-64-

D2-118470-2

r

.":

:F lvTrT Us,-,ISSA EVFl (!PMFNT (US ACTIVF) HOT 120131500021I?.:, : %01 rA'i

lr

( M/M IA'F A31iJ

500 V-Plt onMF OF Ft ODY I F(I tirt ! r(niP lA (rTH tMFI )

-1500

1i.5 12.5 13 13.5 141.5 5 ..ELAPSLD 'TI*,SEC


-65-

D2-118470-2

EPRODCI1LY OF THORIGINAL PAGE IS POOR

US-USSR UFVF.OPMENT (US ACTIVE) HOT 120731500021

S X-M15 COnf f FdOQ OFbI I Fl ( TFST nPATAl WTH o rFL I

TEST-50 1..1

f tS

_ L APSED I I EC

J I- , , I ,i:

10 Hz INSTABILITY

-500

-756

--1000

CLSED T- I T B EC 9 - 2


-66-

D2-118470-2



12.06 = CONTACT US-USSR DEVEIOPMENT (US ACTIVE) HOT 120731500021

12.05 = NO CAPIURE1?.06 = M/M TAPE A01519

TY-AXIS CP D FrFO E CV BODY I FYI (TFST DATA) * (MATH MKIOE )1204

00

7 I Iz 12. 13 135 1 I 4 15.5 .6.5

EL SED 19,S

Figure 5-5. Typical Test/Analysis Correlation, US-USSR DevelopmentTest, USA Active Case 2; Y Force on CSM C.G.

-67--67-

D2-118470-2

US-SSR DEVELOPmEwr (US ACTVE) HoT 1201315000ooo

Y-~Is C MVP OF FORCE 0 B 84C( I FYI (IEZ DNA) (mAT r: rt I

1000

800

TETEST

, j

F 0010 H IN A

I 1. .5 19 19. 20 20.5

ELrAPSED TIME, SEC

Figure 5-5. Typical Test/Analysis Correlation, US-USSR DevelopmentTest, USA Active Case 2; Y Force on CSM C.G. (continued)

-68-

,CPE TIIS[

Iiur !-5 Tyia itAayi orlton SUS eeomTet ,S~tv ae2 oc nCMCG cniud

I ' i l

D2-118470-2

S ,1 US-iS R DEVELOPMEit LUS ArlIlv) HOT 120131500021

5 Z-A S Csr OF F ~~OJ (F'' 1 1

Voo

200

- .o~5 j41 I2.5 3 17.S5 j. l1 I Is 16.5

ELAPSES T11%,SC.

Figure 5-6. Typical Test/Analysis Correlation, US-USSR DevelopmentTest, USA Active Case 2; Z Force on CSM C.G.

-69-

D2-118470-2



-.USSA f.EVt.Pri NI (US ACTIVF) HOI 120131500021

7-AfIS CMt OF MEBcL b' BOW I00 M n 1F lE7 * ((S1T ')2lfi500

K

too iGH

W (. .1.5

is I8.' 19 i9.5 20 .5 21 2 5

ELAPSED TIfE,SEC

Figure 5-6. Typical Test/Analysis Correlation, US-USSR DevelopmentTest, USA Active Case 2; Z Force on CSM C.G. (continued)

-70-

TABLE 5-5

US/USSR DEVELOPMENT TEST DATA/MATH MODEL COMPARISON

TYPE RUN TEMP. AXIAL LOAD1 LATERAL LOAD2 CAPTURE LATCH LOAD CAPTURE TIME

CASE CONDITION NUMBER (CC) TEST . MODEL TEST MODEL TEST 3 MODEL 4 TEST MODEL

i STRAIGHT-IN, 102631500011 +70. +455. +400. t49. +3. +10. +1. 0.02 0.0HIGH ENERGY 103031600011 -50. +530. +590. 59. +12. +31. +13. 0.02 0.0

2 -Y MISS, 120731500021 +70. +1500. +1450. +500. +480. +270. +870. NO CAP. 5 2.74

HIGH ENERGY 110231600021 -50. +800. +930. +320. +360. +65. +336. NO CAP. NO CAP.

4 -Y -Z MISS, 120731500041 +70. +1140. +820. +500. +380. +168. -356. NO CAP. NO CAP.

HIGH ENERGY 110231600042 -50. +730. +970. -330. -360. +250. +107. NO CAP. NO CAP.

9 -Y MISS, JACK- 102631500091 +70. +1030. +835. +465. +200. +193. +390. . 1.67 1.59 o

KNIFE, HIGH 110231600091 -50. +860. +750. +200. +175. +210. +406. 1.73 1.57 .

ENERGY

10 ROLL, HIGH 102631500101 +70. +624. +628. 110. +30. +80. +1. 0.57 0.59

ENERGY 110231600102 -50. +437. +532. 1236. +0.0 +216. +1. 0.62 0.60

NOTES:

1. AXIAL LOAD = Fx2.

2. LATERAL LOAD = Fyz or Fz2 DEPENDING ON WHICH IS MAXIMUM.

3. LATCH LOAD = LATCH NO. 1, 2, or 3 DEPENDING ON WHICH IS MAXIMUM SUM OF TWO HOOKS.

4. MATH MODEL LATCH LOADS ARE CONSERVATIVE.

5. RUN NUMBER 120731500021 INDICATED CAPTURE AT 4.77 SAC BUT LATCH NO. 1 DID NOT LOAD UP.

0

D2-118470-2

5.1.2 (Continued).

raised concerning the validity of the peak docking loads; especially during

testing with the USSR system in the active mode since lateral motion can

change the axial stiffness properties of their docking hardware. Unstable

oscillations, in the Y axis, at 10 Hz appeared in some of the docking cases

following capture. This instability did occur, however, after peak loads

were obtained; and it is believed that the value of the peak load was not

affected.

Both the general low level 10 Hz oscillation and the 10 Hz instability

following capture were attributed to the dynamic response of the DDTS

since the hydraulic actuators possess a bending frequency in the range of

10-14 Hz. However, it is believed that the 10 Hz oscillations, although

undesirable, did not prevent an adequate evaluation of joint docking loads

and capture performance.

The next section discusses a study performed in order to evaluate methods

of eliminating this 10 Hz oscillation.

5.2 10 HZ INVESTIGATION

An experimental parameter study was performed in an effort to eliminate

the 10 Hz oscillations and the 10 Hz instability, and thus evaluate the

effects of the oscillations on measured peak loads and capture performance.

The rate command term in the simulation was chosen as the most likely

quantity to suspect as being potentially responsible because (a) a portion

of the rate command signal is summed with a position signal to make up

each actuator motion command; (b) if the hydraulic actuator bending dynamics

were causing the problem, the rate command could be "feeding" the oscilla-

tions; and (c) it was evident that large rate command oscillations occurred

when the 10 Hz dynamics were noticeable. The following variations to the

rate command signal were investigated:

-72-

D2-118470-.2

5.2 (Continued)

a. Rate command gain variation

b. First order lag filter on rate command signal

(1) With a 1 Hz corner frequency.(filter A)

(2) With a 5 Hz corner frequency (filter B)

c. Notch filter on rate command signal (filter C)

Rate command gain variations were performed using the joint development

hardware with the USSR as the active system. Case 1 (straight-in, high

energy) and Case 10 (roll, high energy) initial conditions were used.

Case 1 was chosen because peak axial experimental loads were higher than

expected. Case 10 was chosen because of a 10 Hz instability in the Y axis

after peak load had occurred.

The results of these studies using Case 1 initial conditions show:

a. As the rate command gain is decreased from nominal, the load increases.

The 10 Hz oscillation is eliminated; however, a 2 Hz limit cycle load

oscillation occurs immediately after peak load.

b. When the rate command gain is doubled, identical load traces are

obtained during peak loading. The 10 Hz oscillation in axial load is

not altered during peak loading; however, the oscillation damps out

sooner.

The results of the parameter studies using Case 10 initial contact conditions

show that:

a. Eliminating the rate command increased the load and removed the 10 Hz

oscillations; however, a 2 Hz instability occurred approximately 20

seconds after contact.

-73-

D2-118470-2

5.2 (Continued)

b. Reducing the rate command gain to one-half the nominal value also

increased the load slightly but eliminated the instability that had

existed previously.

c. Doubling the rate command caused severe divergence following a slightly

smaller peak load.

The results of varying the rate command gain can be generalized as shown

in Figure 5-7., The conclusion concerning the rate command gain is that

a. Rate command is required for structural dynamics because without it,

loads are too high.

b. The rate command gain required to yield proper loads encourages simulator

instability.

First order lag filters described in Paragraph 3.2.4 were then installed

in the rate command.line in an attempt to attenuate the 10 Hz oscillations.

Rate command gain was then varied with the first order lag filter having

a 1 Hz corner.frequency (filter A) and again with a 5 Hz corner frequency

(filter B). US/US development hardware was used for this study. The

following test cases were studied:

a. Straight-in - high energy

b. Roll miss - high energy

c. -Y miss - low energy

d. -Y miss - nominal energy

Using filter A, the first twb cases performed well with double rate

command gain; there were no 10 Hz oscillations and no significant change

in the value of peak load from previously tested cases without the filter.

A value of triple the nominal rate command gain was. required in order to

obtain these results for the third case above. The fourth case exhibited

severe 5 Hz oscillations in the lateral Y direction with amplification in

-74-

D2-118470-2

LOAD

TRUE LOAD

00

RATE COMMAND GAIN FACTOR

Figure 5-7. Effect of Rate CommandGain on Load

-75-

D2-118470-2

5.2 (Continued)

the magnitude of the lateral load. The use of filter B was not as acceptable

as filter A.

The conclusion at the end of this study was that the use of a filter was

a step in the right direction since it appeared to be the solution to the

problem for some cases. However, US/US development case -Y miss, nominal

energy was unstable for any value of the rate command gain when either of

the aforementioned filters was in the line. Since the frequency of the

do.cking dynamics was higher (5 Hz) in this case than in other cases, the

lag filter was not providing the gain required. A filter which would

provide sufficient gain throughout the docking structure natural frequencies

yet provide attenuation at the 10 Hz frequency associated with the actuators

was required.

A notch filter (filter C) was designed and installed on the rate command

line of each actuator. An experimental parameter study was conducted on

the rate c.ommand gain using the notch filter and the US/US development

hardware. .The following cases were investigated:

a. Straight-in - high energy

b. Roll miss - high energy

c. -Y miss - nominal energy

All three cases were successfully tested using the notch filter. The first

two cases represent the cases that had been a problem during development

testing. The third case was the case that could not be successfully com-

pleted with the lag filters.

The effect of the value of rate command gain on the axial load for these

three cases is shown in Figures 5-8, 5-9, and 5-10. In all these cases,

the 10 Hz oscillation was eliminated and no simulator instability existed.

-76-

D2-118470-2


CASE 16 (US/US), ROLL MISS, HIGH ENERGY

1000 L 4,i lI-V -4 t +1-

7T'1Ti rrfrh 1 ;iI 4t d.j I4 k i11 1

- cTh~p ri4 ii1 } 14 1TI 1 -iii # -Ir1f800 ~ ~~~~~~ --F&Y tirh4 i-! i 1 ~i~ti~

+ -4- il400 r Fd' T T_Al Ji Li- - T

1 'it 2I 1 - f lJ

4ffl

H- -1 1 1#-,I"A # ..417,i

200 O FILTER B, USA DEVELOPMEN HARDWARE 1,--

NO± FITR US QULIIATO HADWR -i i -, MtiT--r ILTE CUA+ULFCTONHRWR K

-Lr~ TtiyTIr T~i4~f 4f*j -~ --L - I t Fitl+

-77

44 1 -1 -S-

± H tt 1-1-1

S400 0-4

1-1- _ 4l 1__t , f f T I

(D NO FILTER, USA DEVELOPMENT HARDWARE IMS

SFILTER A, USA DEVELOPMENT HARDWARE200 FITRB UADVLPMN ADWR .iT: NO FILTER, USA QUALIFICATION HARDWAR i IT B S vEDMN AWR

: iFILTER C, USA QUALIFICATION HARDWARE :11:1'-1 -1 if IfIT--H

.......... ... . I1-T

0 . 2.0 3.0

RATE GAIN FACTOR

Figure 5-8. Effet of Rate Gain on Peak Load, Case 16

-77-

D2-118470-2

CASE 3 (us/us), STRAIGHT-IN, HIGH ENERGY

1000f 'H T I~ TLUP i 1i I ~f i Li2 I1ii i i 7o'T ' - iF

Iii i- iY i { 1 ,i ; Ii-

-I-"i!-

1 T i- -1

F 4. T-~~~~~~~~~~~~ -14 *1- 11 'LHI~ _11~~ l1L{IIAi{+ tili44 rH

IT T --~ - 1 H t-1 RB -- m11o 800

- q

X I- -

S4001 1A>< --------- T T -t T,!

L iz !

4 NO FILTER, USA DEVELOPMENT HARDWARE0 FILTER A, USA DEVELOPMENT HARDWARE200 O ~ FILTER B, USA DEVELOPMENT HARDWARE

" NO FILTER, USA QUALIFICATION HARDWARE JA FILTER C, USA QUALIFICATION HARDWARE - I i I

,LNi

±-1# 11i - H1 -T. :- I:i_. : . t'T .... . ...... ;--

S1.0 2.0 3.0

RATE GAIN FACTOR

Figure 5-9. Effect of Rate Gain on Peak Load, Case 3

-78-

D2-118470-2

CASE 5, (US/US), -Y MISS, NOMINAL ENERGY

iI~~~~~~I[I~~~ ~ ffIlI Efi~ ~1i; ti- i ti iji~~ ~~pij~ 11411 h'i -:,r 441 '1 1+

Ir d I ll F kf 1 ; - tit , -h-fl--- 4 ij Lf-- l P41 iT I

Fi11ij -41 1 ihf'i' 1:11000"' 1 k I i' 1! JIl -

i 4 1 Jf 41 01 jti tll f. HI I.1 1 H - , A 4-4 -t r

!I-A, It IT -

I: I4 T1 i t hi T I 1' 14# It_I 1 1 2i±1+i . -Ii---j- Il-A Tii i TIT

41± NE

20011 4 O ILTR S ULFCTO HARDWAR ii-jj I4Fri 1Kll 1 1;1: it~[~

-L -i t- 1 0

0~ 1.02.03.

800 I Tr1 ir

Figure -10 Effect of Rat i on P Li- -79- vi

T 1,41

4..

J4, -H -Hi jUA EVLOM~T HADWRE~

10 1 - . , A -1 jal IATON AR WAR i

fK I 1 -14i 1T i -I- T-

J_ - 1-1 J:, - - , L -1i

T- id 1B03.

Th- R -1 TRt~fRaeGanonPakLad as

4#1-

D2-118470-2

5.2 (Continued)

Figures 5-11 and 5-12 .show typical load traces without and with the filter,

respectively. This particular case happens to be the roll miss, high energy

case. Twice the nominal rate command gain is used with the notch filter in

Figure 5-12. Note the absence of the 10 Hz oscillations when the filter is

used.

Based upon the results of this study, it was recommended that the qualification

test program be conducted with a 9.5 Hz notch filter (filter C) in the

rate command line. The value of the rate command gain was recommended as

twice the nominal value previously used in the development test program.

5.3 US/US QUALIFICATION TEST

The US/US qualification tests were conducted using the notch filter with

twice the nominal rate command gain. [Following the US/US qualification

tests, a check case was run without the filter to verify the validity of

the notch filter. These results are shown in Figures 5-13 (a) and (b).

Identical load results were obtained with and without the filter; however,

instability resulted immediately after peak load when no filter was used.]

Table 5-6 shows the cases tested. The raw test data and correlation plots

of all test cases were published in the NASA test agency report for the

US/US qualification test program. A summary of peak loads is shown in

Table 5-7.

In general, the correlation between test data and pretest-analytical results

was not as good as for the development tests. In most cases, the analytical

load results were higher than test results. After a thorough assessment

of the data available, the major difference between test and analysis appears

to be due to a slight difference in the phasing of attenuator maximum loads.

The analytical data show the peak loads phasing together while the test

results have the attenuators, slightly out of phase; hence, producing lower

loads. The feeling at the present time is that the discrepancy between test

-80-

D2-118470-2

REPRODUCIBILITY OF THEORIGINAL PAGE To(,r ,

US-US DEVELOPMENT TECS 110 HI 032741100161

S -AXIS COMP roC c ON '00Y I FXl 101 I.-P000.1 or

100

0 -L

t - 00 1 t T

r 0

'00 - Ii --. .10 TI -

2,S

Fioo gt s u i, t

1481

Tf . ii

Z-AX15 COP Or FO OE ON 0cODY I rZi o3 I o. , 1-?00, (

,00 -,-, .... ...... 4 -M-Ili-t l .

- 1 00 ; 1 ; r i

I11 115 I? I?.4 Ii 135 II 1 .51 1 5 16

ELAPSEo t I&.SCC

Figure 5-11. Typical Test Results Without Rate Command Filter

-81-

D2-118470-2


US-US DCVELOPMENT TEST 410 HZI 032741100162

X-AXIS COMP OF FORCE ON BODY I FXI O101 .-eo000. KOr

0 ...-

t 5

00

A1

I.i- ....

0015 -5 13 13.5 1 14. a:: 15. 1 i

ELAPSED IME. , C

Figure 5-12. Typical Test Results with Notch Filter in Rate Command Line

-82--82-

I -_3 4 , - -.- e . r- e 5 -2000-- 050841200092 -- -- 050841200091

se 1000

-00

C-

I I I I I II II I I I

-1000--2000

800

' ~ ~I=-- I .I I - I--- - ,:i ,,I-_---- t---------t---- -I-._--------I--_-- ---I----.i =: ,- -.----- .. .....

I--

400

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-400 7=

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-ire53 _. -

I I I I I I I I I I

S-CONTACT .

CAPTURE(TYP)

U+-+-+ i _ __

(a) TIME, SEC (b)

Figure 5-13. US-US Qual Case 9 (-Y Miss, High Energy) Without RateCommand Filter (a) and With Notch Filter (b)

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ORIGIT.AL PAGE IS POOR

TABLE 5-6 US/US QUALIFICATION TEST CONDITIONS

?CLOSIN 3LATERAL 4MISS 5ANGULAR RATE 6ANGULAR ATTITUDE

CASE VELOCITY VELOCITY DISTANCE Roll Pitch Yaw Roll Pitch Yaw TEMPERATURE REMARKSX Y Z Ym .Zm (deg/ (deg/ (deg/

(mps) rps) (mps) (m) (m) sacsec sec) sec) (deg) (deq) (deg)

1 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ambient,hot Straight in

-Y miss2 0.3 -0.1 0.0 -0.3 0.0 0.0 -1.0 0.0 0.0 -7.0 0.0 ambient,hot hirh eyer~

3 0.3 -0.1 0.0 -.212 -.212 -1.0 -1. 0.0 0.0 -7.0 0.0 ambient,hot hi h niss

Y niss jack4 0.3 -0.1 0.0 -0.3 0.0 0.0 -1:0 0.0 0.0 7.0 0.0 ambient,hot knife, high

energy___

5 0.05 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 cold Straight-inI -_ low energy

6 0.05 -0.05 0.0 -0.3 0.0 0.0 -1.0 0.0 0.0 -3.0 0.0 cold -Y misslow eneray-Y; -Z miss

7 0.05 -0.05 0.0 -. 212 -. 212 .- 1.0 -1.0 0.0 .0.0 -3.0 0.0 cold low enerss

8 .11 .02 0.0 .03 0.0 .02 .04 .07 -.9 .9 -1.5 ambient Mean condition

Y miss9 0.3 -0.067 0.0 -0.3 0.0 0.0 -0.67 0.0 0.0 -5.0 0.0 ambient,hot high energy

+Y; +Z miss10 0.3 +0.067 +0.067 +.212 +.212 0.0 +0.67 -0.67 0.0 +3.54 -3.54 ambient,hot hih energy

. The spacecraft with the active and passivedocking systems are designated as body 1 andbody 2, respectively.


Closin, and Lateral Velocities (X, Y, Z)Trasl ational veoci ty components (expressedin the body 2 system) of the body 1 c.g.with respect to the body 2 c.q. .ACTIVE USA

cDoOCr.I:G SYSTEM4 Miss Distance (Ym, Zm) YSTE

Coordinates (Texpressed in the body 2 system) (-7 ) +Z Iof the point defined by the intersection of A5 1 +Y-YA5. AXISthe X axis and the plane passing through TIIROUGIi GUIDEthe forwardmost part of the body 1 docking CENTERLINE)system guides. BODY 1

" Anoular Rates (Roll, Pitch, Yaw) . -eiative rotational velocity components ofbody 1 relative to body 2 (expressed in the +Xbody I system) using the right-hand rule fordirection of rotations about the X1, Z1, andY1 axes, respectively. (ZCSZ2 PITCH YAW 2 (+YCS

6 Annular Attitude (Roll, Pitch, Yaw) -"' ...

Roll attitude is the included angle (meas- BODY 2 - .ured in the Y-Z plane of the body 2 system) PASSIVE USSRfrom the X-Y plane of body to the X-Y ./ ' DOCKING SYSTE:plane of body 1, using the right-hand rulefor direction of rotation about the X2 axis. NOTE: COORDI:ATEPitch and yaw attitudes are the components I SYSTELM, I PARENTESESof the included angle (expressed in the body CORRELATES SIl:ULATOR2 system) from the body 2 X-axis to the body 'l AXIS SYSTE. V'AITMI S/C1 X-axis, using the right-hand rule for I OLL AXIS SYSTEII.pitch attitude about the Z2 axis and yaw +X Pattitude about the Y2 axis. +

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TABLE 5-7

US/US QUALIFICATION TEST DATA MATH MODEL COMPARISON

AXIAL LOAD LATERAL LOAD ATTENUATOR LOAD LATCH LOAD CAPTURE TIMETYPE TEMP

CASE CONDITION (oC)- TEST MODEL TEST MODEL TEST MODEL TEST MODEL TEST MODEL

STRAIGHT-IN +21 360. 400. + 50. 3.0 100. 91.5 30. 1 .03 0.0HIGH ENERGY +70 355. 400. ± 47. 3.0 90. 91.5 40. 1 .021 0.0

-Y MISS +21 1500.(A) 1400. 750.(A) +480 880..(A) 870. 12. 766 NO CAP. NO CAP.2 -750

HIGH ENERGY +70 1600.(A) 1400. 750.(A) -750 920.(A) 870. 16.5 766 NO CAP. NO CAP.

+380-Y -Z MISS +21 980. 820. ±500. 685. 680. 345. 596 NO. CAP. NO CAP.

0 3 -689

+380HIGH ENERGY +70 1200..(A) 820. 1400.(A) -689 1562.(A) 680. 1440.(A) 596 NO CAP. NO CAP.

+775-Y MISS MODIFIED +21 1200. 1770. ±780. -330 615. 890. 510. 241 1.6 1.57

-330

+775HIGH ENERGY +70 1200. 1770. -900. 650. 890. 40. 241 NO CAP. 1.57-330

+310+Y +Z MISS +21 1000. 1710. ±320. +310 630. 1100. 384. 168 3.96 3.97

-16010+310

HIGH ENERGY +70 1050. 1710. ±280. -160 760. 1100. 143. 168 NO CAP. 3.97-160

NOTES: 1. LOADS ARE IN KILOGRAMS. TIME IS IN SECONDS.

2. LOADS FOLLOWED BY (A) ARE RESULTS OF ABORTS.

D2-118470-2

5.3 (Continued)

and analysis is mainly due to inadequacies in math model attenuator data.

Attenuator parameters that could possibly be refined are attenuator preload,

attenuator friction characteristics, and stroke versus area data.

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D2-118470-2

6.0 CONCLUSIONS AND RECOMMENDATIONS

The DDTS provides an accurate simulation of the.dynamics and loads whichr

occur during docking. In particular, the following conclusions can be

made concerning DDTS performance:

a. Initial contact conditions are accurately obtained.

b. Docking hardware capture performance is.in good agreement with

analytical results.

c. Peak loads are in good agreement with analytical predictions.

d. Load and motion time-histories are in good agreement with analytical

predictions.

Although simulator performance is adequate for the simulation of docking

dynamics, it is recommended that further study be conducted to understand

the cause of higher than predicted dynamics during the table frequency

response tests. This knowledge is desirable so that the feasibility of

utilizing the DDTS to perform other dynamic motion simulations and dynamic

tests can be assessed.

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D2-118470-2 ANALYSES OF THE DYNAMIC DOCKING TEST …