Pergamon Computers ind. Engng Vol. 33, Nos 1-2, pp. 217-220, 1997

C 1997 Elsevier Science Ltd Printed in Great Britain. All rights reserved

0360-8352197 $17.00 + 0.00 PII: S0360-8352(97)00078-8

Using Virtual Reality as a Tool to Enhance Classroom Instruction

Lesia L. Crumpton, Ph.D. and Edward L. Harden Department of Industrial Engineering

P.O. Box 9542 Mississippi State University

MS State, MS 39762

ABSTRACT

Because Virtual Reality (VR) offers the opportunity to visualize, explore, manipulate, and interact with objects within a computer generated environment, it is hypothesized to be an excellent educational tool for use in classroom instruction for engineering students involved in design development, evaluation, and validation. The goal of this research study was to explore the possibilities of using VR in Ergonomics courses within the Industrial Engineering curriculum; specifically this paper assesses the perceptions of students and the ability of students to use VR as a tool for performing ergonomic evaluations of work tasks and workstations. The objectives of this project were constructed to answer two important questions. Can VR be used to perform ergonomic analysis.'? How accurately can students perform ergonomic evaluations within a VR environment? © 1997 E l s e v i e r Science Ltd

KEYWORDS: virtual reality, computer simulations, synthetic environments, instruction

INTRODUCTION

The use of computer generated virtual environments, Virtual Reality (VR), is becoming increasingly popular fora variety of applications in today's society. Virtual Reality is advantageous because it allows the designer or user to become immersed within a computer generated environment where they can interact, explore, create, and manipulate objects. This technology allows for the construction of physical environments that are representative, detailed, and realistic. Virtual Reality has gained the most interest in the entertainment sector; however, its potential usefulness reaches far beyond the entertainment arena.

European countries are using VR in areas of architecture, telepresence, scientific visualization, simulation, and software design(Encarnacao et al., 1994). In recent years within the United States there has been an increase in interest concerning the application of virtual reality (VR) in fields such as engineering, medicine, and architecture(Encarnacao et al., 1994). In addition, the usefulness of this technology in design and training applications has been demonstrated by major research entities and industrial companies such as NASA and Motorola.

The aforementioned entities have sought to apply VR because of its usefulness in design development and validation as well as its cost effectiveness in prototyping prior to production. During the design process, VR is used as a tool to represent and visualize prototypes of potential designs. The availability of these designs in a rendered visual context provides opportunities for groups of individuals throughout the company to interact, evaluate and modify designs based on their area of expertise. The creation of this digital representation of a prototype provides a medium for r~I[ 33:|/2-!

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designing complex products that requires less time and cost than the development of a physical prototype. This permits members of a design team to more thoroughly evaluate a larger number of prototypes in a timely cost effective manner.

Because VR offers the opportunity to visualize, explore, manipulate, and interact with objects it lends itself as an excellent educational tool to assist in classroom instruction. Also, because of the interactive nature of VR environments this technology may be useful in allowing students to apply concepts discussed in lecture to simulated environments to enhance the learning/understanding of critical concepts and principles. Students can use this technology to generate, evaluate, modify, and validate design solutions. Also, students can use this technology to estimate parameters of user acceptance, usability and satisfaction of their product designs. This research project was performed to explore the possibilities of using VR as an instruction aid in Ergonomics courses within the Industrial Engineering curriculum; specifically this paper assesses student perceptions and the ability of students to use VR as a tool for performing ergonomic evaluations of work tasks and workstations.

METHODOLOGY

Participants

Twenty students currently (70% males and 30% females, ages ranging from 20 - 27) and previously (50% males and 50% females, ages ranging from 21 - 22) enrolled in the Ergonomics course at Mississippi State University were utilized in this research study. Data on the students' perceptions of using VR environments and the accuracy of their ergonomic evaluation results while using the VR environment was collected.

Procedure

Two research studies were formulated using a VR environment to create a virtual representation of a cereal packing operation. In the first study, after being given instructions on how to manipulate, explore, and interact with objects in this environment, the students were asked to complete surveys that collected data on their perceptions of the work environment and their ability to determine physical design relationships between the objects in the computer generated work environment. For example, the first questionnaire utilized in this portion of the experiment assessed the ability of the VR environment to convey design relationships such as optimum position of the hands while working, optimum amount of reach distance, correct posture, work pace, workstation height, hand coupling, and arrangement of items in the work area. The students were asked to rate their ability to determine these design relationships on a five-point scale where 1= unable to effectively determine and 5=able to effectively determine. The second questionnaire utilized in this first study was designed to determine the fidelity of the VR environment. Students were asked to respond to questions that rated the modes of interaction, visualization, and manipulation within the environment using a five-point scale.

The second research study was conducted to determine how accurately the students performed an ergonomic evaluation of the work area within the VR environment. This study had three parts - initially the students were asked to respond to open ended questions about the workstation's conformance to ergonomic guidelines; secondly, the students were asked specific questions about the ergonomic design considerations of the workstation; and lastly, the students were asked to respond to questions on the fidelity of the VR environment.

VR Environment

In the virtual environment utilized for this research study, boxes were proceeding down a conveyor and the operator was required to pack cereal boxes from the conveyor into a larger box. Here, objects

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were grasped and oriented by clicking the computer's left mouse button as objects approached the operators hand (see fig. 1). Operator movement was accomplished by using the keyboard keys assigned to specified translation and rotation directions. For example, the initial position of the viewer (representing the operator) could be set at various positions. Thus, operators of various heights could be represented at this workstation. Also, the reach distance of the hand could be set to various positions, representing the forward functional reach capabilities of different operators. This application was created using a low-end VR package running on a 133mhz personal computer. VREAM VR development system software was used to develop this application.

Fig. I. Picking-and-Packing task using Virtual Reality

RESULTS

Results obtained from this experiment revealed that students' perceptions supported the belief that the visual representation of the work environment was adequate for performing ergonomic evaluations. In general, 90% or more of the participants felt that it was possible to effectively determine important design relationships such as optimum position of the hands while working, optimum amount of reach distance, correct posture, work pace, workstation height, hand coupling, and arrangement of items in the work area. Also, results obtained from this study indicate that 57% of the students were able to accurately determine changes needed in the workstation to ensure that the work task and environment conformed to ergonomic guidelines and design considerations.

Answers to general questions on the fidelity of the VR environment indicated that some aspects of the environment were realistic; however, changes were needed to improve the realism of the environment. For example, seventy percent of the participants felt that the concepts of workstation design were easy to gleam from this virtual environment. Also, seventy percent or more of the participants felt that the interaction between the user and environment were realistic while 100% of the participants responded that the environment was visually realistic. In addition, 90 % of the participants felt that the relationship between the objects, figures, and the environment was easy to understand. However, fewer than 20% of the respondents felt that maneuvering within the environment was simple. In fact, half of the respondents commented that the method of maneuvering, accomplished using the keyboard and mouse, negatively impacted their performance.

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DISCUSSION

Analysis of the results obtained from this small study support the use of VR as a tool for students to practice evaluating work tasks and work environments for ergonomic considerations. Inferences from this study support the hypothesis that students can perceptually determine physical design relationships within a computer generated environment that are pertinent to making ergonomic assessments in the "real-world." Also, findings of this study indicate that accurate assessments of real-world design relationships can be gleamed from computer generated environments. Thus, these results demonstrate the usefulness of employing VR in ergonomic class instruction and class evaluation exercises aimed at designing workstations and work environments for the human operator. Responses to subjective questions of fidelity indicate that VR environments generated using low-end software packages show promise for economical use, thus, increasing the availability and likelihood of VR exposure in educational settings. Also, the results of this study support the need for further exploration of the advantages, disadvantages, and obstacles of using VR as a tool to enhance classroom education in other design applications within the field of Ergonomics because of the promise of this technology. Also, strides must be made to develop ideas and strategies for improving the modes of interaction and manipulation to improve the fidelity of VR environments.

REFERENCES

N. Adams, Lessons from the Virtual World, Training June (1995), 45-48.

C. Dede, M. Salzman, and R. Loftin, ScienceSpace: Virtual Realities for Learning Complex and Abstract Scientific Concepts, Proceedings of VRAIS '96. ISBN: 0-8186-7295-1, IEEE Computer Society Press, Los Alamitos, (1996).

J. Encarnacao, M. Gobel, and L. Rosenblum, European Acitivities in Virtual Reality. IEEE Computer Graphics & Applications 14 (1994) pp. 66-74.