Bridging Reality and Virtuality in Vocational Training

Kai Schmudlach, Eva Hornecker, Hauke Ernst, F. Wilhelm Bruns

Forschungszentrum Arbeit-Umwelt-Technik (artec)University of Bremen, P. O. Box 330440,

28334 Bremen, Germany++49 421 218 7307

sks/eva/ernst/bruns@artec.uni-bremen.de

ABSTRACTThis article describes work and results of BREVIE, a proj-ect aimed at designing and evaluating a new kind of envi-ronment for vocational training in pneumatics. It is basedon the concept of graspable interfaces, which allow syn-chronous modelling in real and virtual worlds.

KeywordsAugmented Reality, Graspable User Interfaces, TangibleInterfaces, CSCW, Vocational Training, Pneumatics

INTRODUCTIONBREVIE (Bridging Reality and Virtuality with a GraspableUser Interface) is a European sponsored project. It aims atdesigning, developing and evaluating a new kind of learn-ing environment for vocational training in pneumatics.Pneumatics is a field with high relevance to industrial pro-duction. Approx. 80% of the producing factoriesemploy pneumatics, that is compressed air, tocontrol and drive machines. One main benefit ofpneumatics is the possibility of implementinglogical operations and circuits, just as well asdistributing force easily. So this topic remainscentral to vocational training in the industrialcontext. The main characteristic of the BREVIElearning environment is to provide automatic transitionsand links between two worlds which are currentlyseparated for students: the physical circuit, which can begrasped with hands, and the world of abstract symbolswhich can be viewed on paper or on a computer screen.

Goal of the BREVIE learning environment is tocontributes to the following pedagogical objectives: 1)acquisition of basic knowledge in the field of pneumatics,2) ability to build experimental physical/functional pneu-matic circuits, 3) ability to build pneumatic circuits with adigital simulator and to make use of a simulator for experi-menting with pneumatic parts and circuits, 4) ability to rec-ognise symbols of pneumatic components, to read pneu-matic circuits and to design pneumatic circuits with speci-

fied functionality, 5) ability to distinguish between differentmodels of pneumatic circuits, to draw relations betweenthese different models and to review pneumatic circuitsfrom different points of view, 6) train the ability to solve agiven task collaboratively in a group of students.

BREVIEIn vocational training for pneumatics several kinds oflearning material can be found. For our project consortium,the most compelling is the popular pneumatic constructionkit of our partner Festo Didactic which can be used forbuilding functional circuits. These circuits work with com-pressed air and allow a very close representation of real

production environments. BREVIE extends these construc-tion kits by developing technical links to computer-basedlearning media. These automated links between real modelsand corresponding computer representations providesmooth transitions between multiple views on the samemodel to support the development of rich mental models.

We have integrated the following views, each with the pos-sibility to interact with the model and to manipulate it: 1)the physical model, 2) the virtual model in 3D, 3) a sym-bolic/logical view in a simulation software for pneumatics

Figure 1 The BREVIE Learning Environment

In addition, the BREVIE Learning Environment providesaccess to multimedia learning material (hypertext, images,videos and diagrams) which introduces the functional prop-erties of the pneumatic parts. The user can request this in-formation right out of the physical modelling context withthe help of a pointing device. Students just point onto thephysical component with it to look up the component in theonline database.

The link between computer based virtuality and reality isachieved by a “Universal Graspable User Interface” (shortUGUI). The UGUI as an abstraction layer for different in-put device configurations is designed very modular, allow-ing to easily replace one kind of input-hardware by another,such as data-gloves (used in some of our other projects). InBREVIE we use two low cost video cameras which aremounted above the worktable and image recognition ofcolour bar-code labelled ele-ments to synchronise thephysical model with a virtualmodel (see Figure 2). This isthe basis for further processingon the computer.

Since every application fieldrequires a special combinationof components we have intro-duced a highly modular systemarchitecture which permits usto connect easily existing ornew components. The designfollows a client-server approach with a Real Object Man-ager (ROMAN) as the central server unit. Other softwareunits - such as the UGUI, simulation tools, 3D viewers andhypertext browsers - are connected to ROMAN via tcp/ipbased protocols.

BREVIE includes intensive evaluation by work psycholo-gists from the Swiss Federal Institute of Technology Zurich,comparing learning processes and results with and withoutmedia support in four vocational schools all over Europe.The evaluation of the BREVIE system is divided into twophases: the first took place with an early prototype of theBREVIE system, the second is currently in progress withour new version. Evaluation followed a three-step (pre-test,process phase and post-test) procedure with three differentlearning environments (real FESTO components only,pneumatic simulator only and our integrated BREVIElearning environment) compared. These learning environ-ments differ in the amount of tactile experience with pneu-matics components, in the degree of abstraction and thecombination of information formats. A 16 hours lesson planwas delivered to 89 students.

Evaluation outcomesWe measured the effects on learning output (knowledge inpneumatics and practical problem-solving). Despite of sev-eral technical problems and limited functionality of ourprototype the BREVIE students gained a higher amount ofpneumatics knowledge as all the other groups. Neverthe-

less, the main factors for the learning output were previousknowledge in pneumatics and spatial abilities. The rele-vance of practical experience for fast problem-solvingcould be proofed. Based on the positive tendencies shownso far, we expect the results of the current evaluation tomore clearly point out the advantages of our system.

In addition, it came out that advanced learners of pneumat-ics use the system in a different way than beginners: Begin-ners prefer to build up circuits with the hardware construc-tion kit and use the online help system to lookup the func-tional properties of the pneumatic parts. Afterwards, theyuse the image recognition system to create the virtualmodel, validate it in the 3D view and recapitulate the circuitbehaviour with the simulator. Advanced students usuallystart with the symbolic representation in the simulator, cre-ating the circuit and simulating it. When they solved thetask in the simulator, they use the automatically generated3D view of the circuit as a pattern to build up the physicalmodel.

Observations of school lessons, concentrating upon the roleof graspable objects, enforced our belief in the BREVIEdesign. Working with real pneumatic elements was verymotivating for students and led to curiosity regarding theinternal functioning of components. When the teacher usedcomputer tools not coupled with the real circuit, we ob-served that the computer tended to distract students. Thuscomputer tools must be tightly coupled with the task. Thelarge pneumatic tables also seemed to invite collaboration,as nearby groups often watched their neighbours and helpedout of their own accord.

CONCLUSIONGraspable interfaces as means for computer aided model-ling allow using the same physical environment and fostercooperation and shared understanding. BREVIE will beintroduced to the market as “CLEAR: The ConstructiveLearning Environment”. It can be easily adapted to otherapplication fields other than pneumatics.

REFERENCES1 Bruns, F.W. Complex Construction Kits for Coupled

Real and Virtual Engineering Workspaces. Streitz,N.A., Siegel, J., Hartkopf, V., Konomi, S. (eds) Proc.of Cooperative Buildings (CoBuild’99). Springer 1999.55-68

2 Hornecker, E., Robben, B. Vocational Training withCombined Real/Virtual Environments. Proc. of HCIInternational 1999.

3 Ernst, H., Schäfer, K., Bruns, W. Creating VirtualWorlds with a Graspable User Interface. In Nijholt, A.;Donk, O.; Dijk, B. (Eds.) 15th Twente Workshop onLanguage Technology (TWTL 15): Interactions inVirtual Worlds. University of Twente, NL, 1999

Figure 1: A PneumaticElement with ColourBar-Codes