The definition of a variety of assembly, servicing, and maintenance missions has led to the generation of a number of space telerobot concepts. The remote operation of a space telerobot is seen as a means to increase astronaut productivity. Dexterous manipulator arms are controlled from the Space Shuttle Orbiter cabin or a Space Station module. Concepts for the telerobotic work system have been developed by the Lyndon B. Johnson Space Center through contracts with the Grumman Aerospace Corporation and Marin Marietta Corporation. These studies defined a concept for a telerobot with extravehicular activity (EVA) astronaut equivalent capability that would be controlled from the Space Shuttle. An evolutionary development of the system is proposed as a means of incorporating technology advances. Early flight testing is seen as needed to address the uncertainties of robotic manipulation in space. Space robotics can be expected to spin off technology to terrestrial robots, particularly in hazardous and unstructured applications

Jenkins, L.

English

NASA Technical Reports Server

52 - 3  7. 
Space Telembotic Applications and Concepts 
L JcnLins 
NASA Jo&nscm Spact Center 
Houston, TX 77058 
1, Abtrrct 
Tha dahnition afa- drrrmb)r. drminttnura missions has 
ledto the generation d a  nPmba0clp.a trluoboteooapor The remote operation d 
a space tekmbotis w asameuu to- aetmmautpmductivity. Dutuwr 
Mnipulatoruum are con td la i  tiom the Spars Shuttle Orbiter cabin or a Spue 
* d ~ h l ? e ~ d t v c l o p e d b y t h e  statiolrmod9lc. cdntcqmktbcteluobotw 
Lyndon B. Johnam Spue Center through coatnets with the Grt~mman Aemqma? 
Corporation and Mutin Marietta Corporation. Tbac stdies Mined a concept for a 
teluobot with extravehidar activity (EVA) astrtmaut equivdent capability that 
woald be avltrolled from the Space Shuttle. An dutionary development of the 
system is p r o p o d  as a means of in-ting tdmobgy advanes Early fight 
~ i r # n u n c c d c d t o ~ t h e u n a r L i i n t i a o i ~ c ~ ~ ~ t i o n i n r p . a .  
in hamdous and mstm&wd appliatians 
2. Introduction 
krcrcud operations in space with the Spwc strtioa and the Strategic Ikfknae Initiative de6ne a need f o r m  
opemting syatems to as is t  the space a w s  in .ocomplishing a variety of new tunctiaoa The d e  ofthe space crew is 
dunging. with more misicma -the hedbdserwicing d maintenance asa cosktfective mode of opemthg 
satellites. The size of the Spce Stabon mandatcrits.remrblyin space. Other large space systemswill require asaddyon 
orbit Recent Space shuttle missions have demmstmted the ef€eCtivenesa of the extravehicular activity (EVA) crew in 
many of the tasks needed fix future space mmtrucb 'on. assembly, and maintenance. As the nrignitude of mission 
requirements grows, the productivity afthe astmnaut must be inacascd. The use ofEVA is crew time intensive; it rcqoim 
a buddy system as well as an obaerver in the abin. Time spent preparing to leave the cabin, prebreathing oxygen, and 
rmintainingequipmentaddtononproduetivetimc. Remoteopemtings~areamunsofamplifyirrgspacecreworrtplt 
[ 11. One concept for remote operations that has been d&ed in ryne detail is the hlerobotic work system (TWS). 
The basic concept of rbc teIero&tic work system consisb d two dexterous nunipuhtor arms controlled from a mmmte 
station (Figme 1). "he direct control of the arms may be supplemented by interaction rith a computer to perform certain 
tasks or portions oftasks. 'Ibc tasks to be performed range €iwn changing modules and components in the re- of 
na-llitu to the conrtructiaa of I u g c  space sys&rns like the Spue Station- "he opemtor is prwided with sensory f a  
afthe environrmnt d canditiona a t  the work site. Thkappnrch is reflected in the turn "tcicrobotics,'rhich a 
d i a t i o n  ofteleopenting and ro&tics. An objective d t h e  dcvclopmcnt approreh is to increase the prodwthty 
ofthe optntnr through more robotic d e s  having. higherdegree of autMomy 121. 
temstrial situations. The development of a robot rith the capability to operate in space can meet many of the requirtmurts 
of terrestrial applications Current NASA activities in telerobotia consist of studies and ttchnology development at d 
centers. The Jet  Fhpulsion L.boratoy has a groudbased damnstrator. and Goddud Space Flight Center is the lead 
center for the !light tcluobotie mker  for Spree Station. 
3. System Requirements 
"he fbctional requirements for the trluoborwill be derived fmm the seMcingdsatellie satellite repair, rssmpbly. 
and amstruetion; payload handling, and arntingency repair OlspecunfL These M o n s  may be further broken dorn into 
a variety of generic tasks. Exampla ofthe tuks u e  rcrnooino and htalling fastenur. connection of umbilicals and Uuid 
lines, module replacuncnt. and adjustment dthurml bhnkeb. An operatianal colrsidemtion in the requirements isEVA 
equivalency. Space systems are being designed to interface with the proven capability of the astronaut in the 
extravehicularmotilityunit Atcluobotwith~~cqoinlcntap.bi l i tyanintutrclriththtrpsasyrtcm~.1.Dh.s  
an o p e r a t i d  backup in the EVA astronaut 
The perfonname of- tasks will he greatIy d i  by the environment The lack of gravity forces is  the most 
significant effect on manipulative bctiapa b g  is beneficid in a w i n g  lug^ m a s s e  to be handid 0 t h ~  -g 
I 
I -----\ I 
Spuerobotiaankupedcdtospinoffta!mohwtotemstrd - robot..Puti-y 1 
/ 
0 
A robot operating in the environment of npae has auabgies to a robot operating in hazardous or 
551 29 
https://ntrs.nasa.gov/search.jsp?R=19890017085 2020-03-20T01:27:09+00:00Z
effccb ue less bencliad Parts being handed are not positioned and oriented by gravity forces, d the hn play in the 
jo intsafmcehurismskan UPCVtYIP - ty. The hurma factors that ue impacted by the space-flight envimnment relate 
to the interaction with displays and controk Poature is di fkent  in zemg. Eestmnb will be needed hr f'orce-dlathg 
controllus. and visual puccptionamay be distorttd. 
4. System Architechus 
The major elementsofthe TWSconcept am the tcluobot. theamtml statioq d t h e  systezn -. Thircmfigp- 
ration cornsponds to the vehitccture for an automated spstcm as defined by Holcomb and 0th- [21 and shown in Figure 2. 
The robot interfaces with the remote site a t  which the mission fundionr or the state changes are to be accomplishd The 
control station is the operator's interface with the system through controls and disphp. The system procmor impkmcnts 
the operator's cammads and dimts feedbrdr of the results. The potential ofthe architecture is illustrated in Figwe3 as 
an example of the relatiomhip of functiollll components of the spkxn. Thor relationships may bc defined as operator 
interface. task planning and reasoning. control execution. and ae&g lod puccptia~. Effectively, there is an operator 
control loop. an executive control loop. and a local control loop at the remote d k  T h e  control loop provide fecdbwt and 
interaction to enable accomplishing tasks in an e f f d v e  and productive manner. 
5. Conceptual Designs of TWS 
The Lyndon B. Jahnson Space Center ha5 studied the Tws thmugb cootrub,with Crumnun Aemp.cc Corpcudon 
and Mutin Marietta Corporation. Figure 1 illustratrr the system umngwmit and mSpr compaacn~ fix the initial 
application on the Space Shuttle Orbiter. The system elements Io@dy &vi& incp the robot work station rbac the 
physical tasks are to be .ccomplished, the controlstation with the opentdsdirplysaad controls, md the system-r 
that providesthe computer power and logic to make thesgrtemftmdk. yobility to& the work site k aehievedrnth 
the Shuttle remote manipulator system (SRMS). Stabilizer unts bald the TWS in position a t  the r r k  site. kter 
applications of the TWS may achieve greater mobility by using 8 firc-flying module similar to the manned W d n g  
Uaii 
The mbot work station kns d p d a t o r s  and cad &ktom 00 prthm phJdal t.sL.. Senor rrritu manitor and 
measure conditions at the work site. Although wort-site conditiona in space are more structured tlua in m y  turcstn'al 
state ofthe task armponcnts is crit ial  because dthe  iarrrradbility in rpra; thus, tbc need far a pmxptive d adaptive 
syattm. The conecpt ofEVA equivalency is a strong driver in d.rcbpacnt ofthe dguration [3l. Th capability d t h e  
EVA nstroaautsto PufwmdUtMustaaksin the svricingd repairof~tellitesh.. been well dmum.brtd in ruent  
Space Shuttle missions Satellite designs are now being impleaunted In reymsc to the dcmonstratd EVA capability. If 
theTWSean purOrm tasks equivalent to those ofthe suited rutroaaut. there mll be sucllites to work ob 
'ccon6gwationsinthecoa~emccpts 
[4 aad 51. Crummra hasearrid the human analogyone stcp ~ ~ ~ t b c u r o n y m  "SMTEarthe Surrogate 
Astnmaut M.ehine shown in Figure 4. The principal amera location respomb to tbe operator's eye-bhand relationship. 
Orhvameruon the arms provide additional viersofthe task. proldmity, T o m  fccrlb.el. and tactile wndngsnpplemcnt 
tbt- visual aids. A third arm functions to s tabi lk  t h e m  8t the work site. Aduterws arm Simikr'rotheOLhvums is 
situatiana the amfiguratioo a n n o t  be as well cootroUed asinmortmbotic urn in idastry. TheabilitytodacnrPlrv - t h e  
The EVA eguivaluxy requirement haa resulted in strongly an 
30 
e 
B 
OPERATOR 
I 
aKxmow 
STATUS 
OPERATOR 
INTERFACE 
TASK 
DESCAIPTIGN 
TASK PLANNING 
AND REASONING 
low__I 
STATE 
OBSERVABLES 
SENSING AND 
PERCEPTION 
IISTERNAL 
OBSERVABLES 
CONTROL 
EXECUTION 
I 
COMMANDS 
1 
t 
STATE 
CHANGES 
c 
t 
OPERATOR 
INTERFACE E)(fCUTIa p 
O I U I T O l l  
 lp 
I- 
I I  l l  
$ k r p  SENSING AND 
- G  
OPERATOR CONTROL EXECUTIVE CONTROL LOCAL CONTROL 
F i v  3. A~tolpatd - control uchit#torr 
31 
. 
-- 
BATTERY 
LIGHTS AND 
WRIST CAME- 
DEXTEROUS 
MAN1 PUUTORS 
LGRAPPLER FIXTURE 
FigwtC CiraDmrndstatimcooccpt 
The cpemtnr interface at the control station is critical for effective intMctioa with the robot Interiw volume k at a 
premium in spate, particularly on the Space Shuttlr For example. the design ofthe SRMS was  drive^ to a reaohed-rae 
control system hecause the m p t  volume to optrate a replica master controller for such a long um was dif!icult to 
seammdate in thc Orbiter cabin. Six-DOF mte amtrollem are propod by Crummur (Figure 6) and Martin :F'igure 7). 
Technique for amtrolling a 7-DOP arm is 8 tahdogy development -e. Mutin has suggested a hJbrid control sysuzm 
that ufc~ rate or &tian depending on the task. -a controllerr to &ti= the d e r  dexterous ann8 are 8 porcntid 
tradcoafor TIKS application. 
DOF CONTROLLER 
PERIPHERAL 
ENTRY PANEL 
ADJUSTABLE 
RETENTION SYSTEM 
I U 
STEADY 
WAIST 
~~ 
Figure 6. Crumman TWS control station concept 
6. Progmm Development 
"he dcrclcpment plan for the TWS is  prediated on the need to inemam the productivity of the uer; thercforc. the 
plan is evolutionary in natprc. In this logic. the TWS design must be capable ofincerpomtingtechnology uivuuxs ma they 
kmmr available. This approach will depend on modular subsystems and prcdse definition of interfiuea to enable the 
adoption ofnewer innovations. Another feature of the logic is the evolutionary route of teleopemtion to teleprcscna to 
supervisory control to suprviad adaptive robotics 121. The implicatioas of this approach are evident in the selection of 
feedback sensors that will be compatible with expert systems and artificial intelligence needed for adaptin robotics The 
telembot technology program of the NASA Office of Aer~naut i~r  and Space Technology is consistent with this development 
approach. In addition to the ground demonstration telembot a t  the NASA Jet Propulsion Laboratory, a protoflight testbed 
has been proposed to support research and technology experiments, to validate ground simulations, and to demonstrate the 
utility of a dexterous manipulation capability for remote operstions in space. The flight telerobotic servicer progmm for 
Space Station is currently being defined. The antiapated result is a telerobotic system that will have application on the 
Space Station. but will have been developed and demonstrated on the Space Shuttle. 
:TION 
Figure 7. 3dartin TWS control station concept 
33 
7. Summuy 
ThedeocLopmcntof8oclvobotieuw'krjntanora simihrconccpt repracntr avda8bk rem- k p d o I d n g 8  
varicgof~iothePnrLructPredandh.tudouscnvimnmcntotspaa. DcPclopnrntanddammstmtioainRighttesta 
the Space Shuttle can lead to applications 011 the Space Station for the mobile nmotc manipulator system, the rtellite 
semias. and the orbital maneuvering vehicle. A system meeting these requiremeats can he of great use in developing the 
tnhnology needed for auny tenutm 'el appliatioas of te1crabata Telero&ts rill find uses in personal service functions far 
disabled and aged people and io huudour situations sauh as u e  found in amstruetian and .(piculture. 
8. References 
(11 
[21 
L Jenkins and R Olan, "Remote @mating Systems for Space-Bad ASME Coderenee Camputem in 
Engineuing.IarVegyNevad8,Augwt12-15.1984. 
L. Holcoarb. R. h n ,  and M. Moatemerlo. "Overview of the NASA Automation and Robotics Racrrrh hogram,. 
AIAA/NAsA Symposium on Automation. Robotics and Advanced Computing for the National Space Program. 
Washington. D.C.. September 4-6.1985. 
L Je- 'Telerobo~c Work Systems Concepts," AIAA/NA!U Symposium on Automation, Robotics and Advanced 
Compubng for the Nabonal Space Program, Washington, D.C.. September 46,1985. 
Telepresence Work System Definition Study." Crumrrmn Aerospace Corporation, Contract NAS 917229. October 3. 
1985. 
Telepresence Work System Definition Study," Martin Marietta Aerospace. Contract NAS 9-17230, Oaobcr 3.1985. 
[3] 
[4] 
[5] 


Space telerobotic systems: Applications and concepts

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