Thesis (MScEng) Stellenbosch University, 2014 / ENGLISH ABSTRACT: Teleoperation as a field has seen much change since its inception in the early 1940s with Dr.
Raymond Goertz producing the first teleoperation system for manipulating radioactive
materials. With advances in core and supporting technologies, the systems have grown
in complexity and capability, allowing users to perform tasks anywhere in the world irrespective
of physical distance. The feasibility of such systems has increased as the drive for
use of telepresence robots, exploration robots as in space exploration, search and rescue
robots and military systems such as UAVs and UGVs gain popularity.
This prompted the development of a proof of concept modular, user centred telerobotic
system. The current project is the second iteration in the development process.
Teleoperation and more specifically telerobotic systems pose a challenge for many system
developers. This may be a result of complexity or the wide assortment of knowledge areas
that developers must master in order to deliver the final system. Developers have to balance
system usability, user requirements, technical design and performance requirements.
Several developmental process models are considered in context of Engineering Management
(EM). A larger Systems Engineering developmental process is used, with focus on
the primary and supportive EM components. The author used a hybrid developmental
model that is user focussed in its approach, the User-Centred Systems Design (UCSD)
methodology was adopted as the primary model for application within the two distinct
developmental categories. The first category hardware and system integration utilised the
UCSD model as is. The second - Software development - relied on the use of agile models,
rapid application development (RAD) and extreme programming (XP) were discussed
with XP being chosen as it could easily incorporate UCSD principles in its development
process.
Hardware systems development consisted of mechanical design of end-effectors, configuration
management and design, as well as haptic and visual feedback systems design for
the overall physical system. Also included is the physical interface design of the input
(master) cell. Further software development was broken into, three sections, the first and
most important was the graphical user interface, haptic control system with kinematic
model and video feedback control.
The force following and matching characteristics of the system were tested and were found
to show an improvement over the previous implementation. The force magnitude error
at steady state was reduced by 10%. While there was a dramatic improvement in system
response, the rise time was reduced by a factor 10. The system did however show a decrease
in angular accuracy, which was attributed to control system limitations.
Further human-factor analysis experiments were conducted to test the system in two typical
use-case scenarios. The first was a planar experiment and the second a 3D placement
task. The factors of interest identified were field-of-view, feedback vision mode, and input
modality. Heuristic performance indicators such as time-to-completion and number of collisions
for a given task were measured. System performance was only showed significant
improvement when used with haptic control. This shows that the research into haptic
control systems will prove to be valuable in producing usable systems. The vision factor
analysis failed to yield significant results, although they were useful in the qualitative
systems analysis.
The feedback from post-experimentation questionnaires showed that users prefer the Point
of View as a field of view and 2D viewing over 3D viewing, while the haptic input modality
was preferred.
The results from the technical verification process can be used in conjunction with insights
gained from user preference and human-factor analysis to provide guidance for future
telerobotic systems development at Stellenbosch University. / AFRIKAANSE OPSOMMING: Telewerksverigting as ’n gebied het al vele veranderinge ondergaan vandat die eerste stelsels
deur Dr. Raymond Goertz geimplementeer was in die vroeë 1940s vir die hantering
van radioaktiewe materiale. Met vordering in kern en ondersteunende tegnologieë, het
die telewerksverigtingstelsels toegeneem in kompleksiteit asook gevorder in vermoeënsvaardigheid,
wat gebruikers in staat stel om take te verrig vanuit enige plek op aarde,
ongeag die fisiese afstand wat die gebruiker en die werksarea skei. Die lewensvatbaarheid
van hierdie stelsels het ook toegeneem weens die belangstelling in teleteenwoordigheidrobotte,
ruimtevaardige-robotte, reddings-robotte en militêre-robotte soos onbemandelug-
voertuie (OLV) en onbemande-grond-voertuie(OGV).
As gevolg van die belangstelling in telerobotiese stelsels is die ontwikkeling van ’n modulêre,
gebruikers-gesentreerde telewerksverigting stelsel onderneem. Die huidige projek is
’n tweede iterasie hiervan.
Telewerksverigting, en meer spesifiek, telerobotika stelsels ontwikelling, vereis dat stelselontwikkelaars
’n verskeidenheid kennisareas bemeester. Die ontwikkelaar moet ’n belans
vind tussen gebruiker vereistes, bruikbaarheid asook tegniese ontwerp en prestasie vereistes.
Menigde ontwikkelingsproses modelle is oorweeg en behandel in die konteks van
Ingenieursbestuur (IB). ’n Stelselsontwikkeling proses is gevolg met ’n fokus op primêre
en ondersteunende IB komponente. ’n Gemengde ontwikkeling is toegepass tot die projek
wat die gebruiker as ’n hoof komponent van die stelsel in ag neem. Die oorhoofse ontwikkelingsmodel
is die User-centred Systems Design (UCSD) proses, wat vir beide hardeware
en sagteware ontwikkeling gebruik is.
Vir die hardeware ontwikkeling is die UCSD toegepas soos dit uiteengesit is in die literatuur.
Die sagteware ontwikkeling is voltooi met behulp van ratse metodes, “Rapid
Application Development” RAD en “Extreme Programming” (XP) was oorweeg en XP was gekies as ontwikkelingsmodel. XP was die natuurlike keuse weens die gemak waarmee
UCSD metodes en prinsiepe kon geinkorporeer word in die ontwikkelings proses.
Hardeware onwikkeling het bestaan uit meganiese ontwerp, manipulasiegereedskap ontwerp,
konfigurasie bestuur en ontwikkeling asook haptiese en visueleterugvoer stelselsontwerp
van die fisiese stelsel insluitend die fisiese koppelvlakontwerp van die meester sel.
Verder is sagtewareontwerp opgedeel in ’n haptiesebeheerstel met ’n kinematiese model
ontwikkeling, videoterugvoerbeheer en gebruikersintervlak ontwerp.
Die vermoëe van die stelsel om krag insette na te boots was verbeter met ’n gestadigde
verbetering van 10%. Die reaksietyd van die stelsel is verbeter met ’n faktor van 10. Die
stelsel het ’n verswakking getoon in die algehele hoekakkuraatheid, die oorsprong van die
verswakking kan aan die beheerstelsel teogeken word.
Verdere menslikefaktoranalise eksperimente is voltooi om die stelsel in twee tipiese gebruikgeval
scenario’s te toets. Die eerste, ’n platvlak-eksperiment en die tweede ’n 3D plasingingstaak
eksperiment. Die faktore van belang is ïdentifiseer as, visie-veld, terugvoervisie
modus en insette modaliteit. Heuristiese prestasie-aanwysers soos tyd-tot-voltooiing en
die aantal botsings vir ’n gegewe taak is gemeet. Stelselprestasie het slegs aansienlike
verbetering getoon wanneer die stelsel met die haptiesebeheer modus bedryf word. Die
visiefaktor ontleding het geen noemenswaardige resultate opgelewer nie.
Terugvoervorms was na elke eksperiment voltooi. Vraelyste het getoon dat gebruikers
die oogpunt van ’n lae hoek en 2D video oor 3D video verkies, terwyl die haptic beheer
modaliteit verkies word.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/86516 |
| Date | 04 1900 |
| Creators | Smit, Andre |
| Contributors | Van der Merwe, A. F., Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xv, 257 p. : ill. |
| Rights | Stellenbosch University |
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