Data processing telemetry system with adaptive control for application in space vehicle environmen

Massey, H. N.

English

NASA Technical Reports Server

Advsnced Telemdry System 
with Adaptive Capability 
prepglnd by: E. E. Massey 
Ibte: 25 Febnary 1966 
https://ntrs.nasa.gov/search.jsp?R=19660022090 2020-03-16T20:40:20+00:00Z
FOREWORD 
This report  describes work performed by Lockheed Xissiles & Space Company 
under Contract kIAs 8-5110 en t i t l ed  "Advanced TeleEetry System with Adaptive 
Cqmbility" f o r  George C . Marshall Space Fl ight  Center, Rational Aeronautics 
and Space Administration, H u n t s v i l l e ,  A l a b a ~ a .  This report  is f o r  the  period 
1 July 1964 through 25 February 1966, and covers vork performed on the second 
and t h i r d  experimental f l i g h t  pacbges. 
mental f l i g h t  package is covered- 
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1 
A l s o ,  t i e  r e t r o f i t  of t h e  first experi- 
Seven (7) previous summary reports, 
1 (~4sc/657617, A035672, 664229, 8-39-65-1, 8-29-65-3, 8-39-66-2, =Id 669224) 9 
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I t h i s  report. 
I cover other work completed p r io r  t o  or  concurrent with the work reported i n  
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Section 
1 Foreword 
1 htrodrrctfon and Su~nary 
2 Design Improvements 
2.1 General 
2.2 C i r c u i t  Design Changes 
2.3 Mechanical and Packaging Design Changes 
3 Functional Testing Problem and Corrective Actions 
3.1 General 
3-2 
3.3  
3.4 
Tes t  of the Second Experimental Fl ight  Package 
T e s t  of Third Experimental Flight  Package 
Eet rof i t  and Test of the First Experimental 
Fl ight  Package 
4 Conclusions ar,d Recommendations 
1 
1-1 
2-1 
2-1 
2-1 
2-3 
3-1 
3-1 
3-1 
3-5 
3-8 
4-1 
5 References 5-1 
ii 
Section 1 
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of the data f. m t .  
multlplexe8 &fa cont;ained a high atgptC of redrmdsncy. It was reasoned 
%ha%, if a system could be devised w h i c h  examines the data for redundant 
In partirylril., it was found that time division 
1-1 
properties srtd transudts only the infomation actually reqyired for 
reproducing the data rartstloae, 8 significant reduction in  bandwiah 
requirements could be achiered. 
canpressor, has been devised t o  accaupUsh this operrrtiun. 
A system, known as a telemetqr data 
me gmer==Z spgmaph to the vehAcle-borne system design was to add the 
redundancy reamal caplpbilitp t o  an exist ing poll telemetry system to 
rninim%ze new equipnezxt -. Redundancy remmal vas i m p l k e d  
with 1 6 s  based on the pred%ctioa that the next data sample value w i l l  
be equal, v%th in  specifled to- umbts, t o  the last sanple value 
transnt%tted. 
w c . )  
was -sed for increasiqg the tolerance limits as a fhetion of buffer 
==I==Y* 
(ThLs .bs also referred t o  as zero-order, floating-aperture 
To mlnimhe the probhility of buffer memory overflow, a method 
The work u n k  Contract HAS 8-5U.O bss been acemplished in six phases 
aed has %nehded tasks frw concqhal and feasibility studies through the 
proitustktn of thme experimental flSgM systems. Most of th is  work has 
bee!n eovered in pireriats reports. 
Dux=%= the first 
through pbssrt IY and 
study, desdgn and Cosstactian of a non-flyable prototype system, test and 
mhs, work on Contra& HAS 8 - 5 U O  was sonnpleted 
in Reference 1. This included a conceptual 
evaluation of the psrototype, and the formulation of specifications for the 
design and developtmt of a flyable system. 
1-2 
1 
Under pbsse V, reported i n  Reference 2, improvements t o  the wear vere 
investigated and a revised p e r f m e  specification was formulated. 
The feasibiUty of 8 reference memory with a capability of both DRO 
and HDRO St0rSg;e was ienreStigated and a workable solution was obtained. 
Sources Oi sapikrblr manaxy cares were located and circuit develope& of 
mving anr i  sm8f cireui.t;s ims a€C-lt&eii* S@em p 2 f l G - e  ~bplicatims 
resulting frora the use of a 'Olarge" m e r  memory was investigated. system 
and. sirmalt designs were accoerplished t o  incorporate a "large" (1,024 word) 
bzff'ex cenory into the system. M o m a n c e  specifications were revised t o  
reflect these memory cbanges am3 other &singes t o  performance requirements. 
\ 
Under Phase V I 0  hposted ip Beference 3, the system and circuit design of 
the DBta Cclmphgsar were rexlscd to neet the re-8 established 
during the Wsse V VDPh. #ochadcal and packaging desig~ of an experimental 
flight pachge vas ccrplakd. !be first qrimextaf fligtrt peckage w a s  
lxlilt and tested for W i a n  vftbin spice vehicle enviroments. 
I 
Test results obtained w l t h  the rtrSt experSmedal flight package were used 
in m&ing design correctians. T k n ,  s second and third -81 flight 
package were Wt and tested for operation over the tempe!rature range. 
Also, the  f'2rst 
mferrncc nmnoxy of 480 words (for econuqy, 240 active and 240 d~neay words 
were origLnally included in the reference memory of the first package). 
f l i g h t  package was retrofitted t o  have a 
Concurrent a t h  the Phase VI work discussed above, additional tasks under 
Phase V were completed. A description of two types of digital filters, 
=/m394 
suit8bl.e f m  -on filtering, w i t h  examples and discussion, 
was even in R e f e r e n e e  4. Results of preliminary implemeoltation studies 
described 3.n Reference 7. 
1-4 
Section 2 
-s 
2-1 
WgL&t& Cipcedts. 
folhwer oatputs. 
DC loads t o  graund w e r e  added to  all emi.t.&er- 
Also, DC loerds t o  ground were added in seveml 
l=t%(l8Bi3 t o  b r e r  the Icp.el of the clock ixlput to  mp-flap C I r m t S 0  
I;ta a f e w  bstaaces the logic signals to gate inputs w e r e  revised to 
dx5vers. In the reference memory, the XDRO sense amplifier ef-t w a s  
of %he drivers. 
2-2 
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Mecha;ldcal rcrnd ~~ design changes w e r e  made t o  accrmnndnte 
ei&t changes, to correct deficicades disclosed dasdng work 
Qp the first SyStea, and t o  3lqlwe ease of fgbric&ion OF assembly. 
2-3 
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The reference plcppor~ design was modified to provide increased stiff'ness 
at the t a p  and battaa cb the -3.y. A t  the top, stfffe~ers 
w e r e  ad&d to the Mt driver clxmdt board and the reset driver 
dretdt baard. A Figid polpr&mae faarn vas also added to the reset 
dx&- mt Imam%. A t  thc battun of the s\lbassesab2g, stiffeners 
were added t o  the EL- circuit board. 
2-4 
3.2 Test  of the sceaad-pli&ba 
T h e ~ s a d ~ Q b ~ # c I H . d ~ ~ p a c k a j g a w a s  
shlilss t o w  ~ V i f b t l &  farst pecbslp (seelkfkmmx 3). 
Circuit design chnges, tlMdr were lik as a result of 
the First pelsage, were iamd t o  be eff'ivt. Repb-s  for the two 
ty-pes of diodes vhich were probrans in the first package proved t o  be 
satisfactory. 
v%th 
The silicon tunnel diodes, used as threshold elements 
3-1 
in the memory sense amplifiers in the second package, performed 
as desired and with& the high =lure rates previously experienced 
vfth gallim arsenide tunnel dlodes. The hi& failure rate of 
--ion microdiodes was found t o  be corrected. (These 
doubb-jm&&m dioQs 81c in d e s  with logic W s  to the system 
to iPcrsswc otr 
It yla8 fasnd tfraf; use of the rtplacemuxt double-3upctiap diode resulted 
a wffllbaa tolerable "0" logic level vhich -vas equal or urceeded the 
goel far a n  -1 tcaKpexatures of +7o'c and b?lar. 
"0" logLC l eve l  which CBP be tolerated.) 
Observed 
valses  of bp't 
m: 
leveb vhich pmdnced correct system uperation 
-20 
+e 
+70 
71.4 
1.15 
1.0 
c2.4 
c 2.5 
2.4 
3 -2 
During tests using the 288iE system clock rate, several mrgind 
t iming problems were disclosed. These m e  generally caused by the 
duration of me-shots and vere comected Qy a reduction ip dmation- 
Two other pmb- card involrtd the rpagaetlc ~w nroikles o f  
the reference memory. 
during tenperature eycligg, cracked glass-cased diodes. Corrective 
action included removal of epaxy from arrruad =odes, Fcplacspr;llit; of 
Stresses produced by the epoxy ccmfo& coating, 
3 -3 
crack& diodes, aud rccagt- w i t h  a silicone material. A problQl 
of corrosion, between copper conductors and a magnesium alloy plate, 
developed during temperature cycling- 
which condensed on the package during low temperature t e s t s ,  vithout 
c~plet, bad acted as an electrolyte b e t w e e u  the metals. A l l  reference 
memory aragntties mndules w e r e  removed, inspected for damage, repaired, 
lpecottted and reinstalled. 
an epxy coating bad been applied to  the metal Surfaces and the package 
is designed t o  contain an i n t e a  atmosphere of d r y  nitrogen gas.)  
It yas concluded that moisture, 
(As a protection against this sort of problem, 
144 Kc System clock voltage 
in Volts 
In addition t o  verification of correct performance of data hndling 
iknctions, observations of input and output pmmeters were recorded. 
These were: 
~ 14 -35 ~ 
, 11-56 
17-25 
17-17 
17-37 17-25 
17 -4 
17 -55 
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3-4 
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Aprplitude Rise Time in 
Tmpratue in volts P-P microseconds 
-2O.c 9.5 1.5 
+25.C 10 1.8 
I + I t a t 
1 t-io*c 1 2.0 I m 
* Across losd of 200 Orpa resistor and 0.003 microfarad 
capacitor ia parallel . 
The p e r  i q x &  to the package and the canpressed PW signal output, 
as 0;brrarril and fsbulated above, were within the limits specified. 
A d d i t i o n a l  -1 waditioars were disclosed when Operatirag 
at the 288 Kc clock -e. earrectio~ were made 
durtrtion of oxus-shats. 
in PsragFSph 3.2 of thfs section.) 
reducing the 
('lmesc w e r e  not the same one-shots discussed 
3-5 
On chedcbg for correct operatitxi of' the red.undant samp3.e routine, 
it yob discovered not t o  be ftmctfoaing entirely correctly. A wire 
Ilst erm? a d  caused a wire to be misloc&ed. Also,  it was concluded 
that the reihndant sample routine probably bad not functioned entirely 
Coarctw in the first and second package - it oinly appeared to work. 
A&=Uj, rrdtmdsnt q l e s  were accepted during the .sster fmme 
period l a  which a new cycle of the rrdxmdant sample roartiPC was 
started apd tb2s is uhgt; had kcn izrterpreted as indicatipg that the 
redunda& was warm correctly. !Che *rip@; e x m r  
prevented stoxage of the r&wadt& sample tag in  the reference meamry. 
A P t a  c o m a  of the vfripe CTIDF, proper operation was demonstrated. 
A p c i ~  pmblrrm Of faulty -S OCc\ulrdvith the th i rdp~r? l ragc*  
Dux%ng t-ure tests, if was f-d that the current pulse amplitude 
fFQa tbe refemace sesnory "write" drivers did nut properly as a 
of temperatame. ( ~ b +  eurrent drivers are des-d t o  have a 
xmgative taqerature coefiicicnt to coanpensee for a change in fcrsite 
memory core charactcrfstics.) The cause of th5s problem was traced to 
type VToJ8 e-t -ipg si=- resist- 0bta-d fFarn 
Vector state -ea (Vectnr oi ~urden  vision 
of W t e d  A i r c n f t  carpcnrrticm). A test of this resistor type 
%a the res%- ramge oi 12 t o  30 alms iadfcated a positive temperature 
coefficient of Coarsiikmb~ less thaa the published value of eO.'@ per 
degree C. Also, the tt!aIpemture coeiiiciurt was faund t o  vary widely 
from resfstor to resistor. Based OQB prbrisbed information which implies 
3 -6 
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that the type PT-1/8 resistors axe electrically eqyivalent to Texas 
Instruments type =-l/8 resistors, IYISC procurement had chosen to 
buy the type ~ ~ - l / s  resistor far the third package. 
l!M-1/8 resbs&ors w e r e  used for temperature compepsafion in the first 
and secrmd packages.) corrective action was t o  repha trpe W-1/8 
resistors w%th type m 4 8  resistors in the "write" driver circuits. 
mere are type pT-1/8 resistors fnst;alled elsewhere in tbe third flight 
pacbi@~ - i &  were not replaced. RepLacenent; of these &her type 
pT-1/8 reshtops was nut ca~saldered warranted because she tenperature 
coefnlced is less critical. 
(Only type 
A f t e r  rcrlffa;tfan of Oorrret crperation at each tenpen&ure, the 
follarfiqg okwerraticms of 3npt and &p& panncters were recorded: 
-20 
+a 
+70 
i 
2.5 
2.5 
2.5 
a -7 
I t 
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Hate:  W power measumments, the data -le 
-mit=fh input caPltsined 5 0’s and 5 1’s. 
I f  1.5 1 1.6 
fhe process of procuring the additional rzunory parts, it w a s  
disearclzd tbst the two-hole m e m ~ l y  con68 for ItDRO storage, w e r e  no 
bsger sntila;ble vith the same specificat%un limits as those 
grrriousM ofikrined. Two-hole cores with sliphtly higher drive 
-8 w e r e  substituted in the added 240 vofds of ~ x y .  
To cmpnsate for this, the '-ten current drivers, associated with 
these sdded senoxy cores, vere adjusted to provide a 
higher output amplitude. 
tests. lo particular d l f Y i d t y  arises use of these fvo-fiolc 
cores with higher drlve requinsmts, other tban a reduction in drive 
nwgia for the orse-hole mo cores- 
This vas accomplished duriag traardlerrel 
R d n g  ratrafit work, the t3,isassclpbled rogic and reference - 
were inspected for dzmsge t o  2xteamCk parts reaittiag 
fram prerfasr; cmi~onmeata~ tests (shake, -, and temperature). 
The only 
memory (causeti 
diodes and temperat- c j r c u ) .  
farad vas cracked glass-case diodes In the reference 
use of an epoxy = t e a l  to c ~ o x m r i ~  catt the 
corrective actian was t m  as
dcspcrikd in 3.2 the se~oad packagt. FCW p e ~  pa~ts 
uhlrd to the i'inst pactagc a sflicoac mtiterial was used fur caaiomal 
eaxt-. A cheek for c0rr0sim, as had been found in the second 
pscbqp, revealed no evidence of corrosion - apparedlj pItevented by 
a better pmtective coating of epoxy and less exposum Co moisture. 
After retrofit sewrk,  the first package vas Amctianally tested and 
no major difficulties were ecperienced. The following input and 
3 -9 
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"0" of 1.4 volts 
#rt-- "1" rb 2.5 r o l t s  
3 -10 
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Section 4 
There are adiwirrsl tantn nc<nrodcdliuei& arc &Iqpsctcdto bad to th 
successrPl ap@lcz&i#t af tclaPetrg qystess wSth sdarptive 
capability aboard space vehicles. These additional tasks are as follows: 
4-1 
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1. Dcltcl.laiRtiam, by experimental t e s t s ,  of the detail 
pe!rfarammce criteria for a f l ight  system. R e s u l t s  
Shar'ldbe usable as a guide in pmgm&ng the 
d&aU pema=mx of the experiarental mgbt 
=Et=4m= 
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The fallwfag reicrrcnas u e  reports produced €y Lockheed Missiles 
and Spce 
Systaa uith A m * -  CqmbiUty". (Monthly progress reports are 
QP Cattract IUS 8-5110 entitled "Advanced Telemetry 
not listed.) 
Studies of Advanced CQlPhs sion Algofithms, by W. R. Bechtold and 
U. E. Smith, R e p o r t  Bo. 8-39-6-1, 3C June 1965. 


Advanced telemetry system with adaptive capability Final technical summary report, 1 Jul. 1964 - 25 Feb. 1966

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