Investigation and Evaulation of a Virtual Reality Vocational Training
System for General Lathe
Jung-Min Shin
1
, Kyoungbog Jin
2
and Sang-Youn Kim
3
1
Institute of Creative and Convergent Education, Chunhbuk National University, Cheongju City, South Korea
2
Department of Mechatronics Engineering, Korea University of Education and Technology, Cheonan City, South Korea
3
Department of Computer Science & Engineering, Korea University of Education and Technology,
Cheonan City, South Korea
Keywords: Virtual Reality, Vocational Training, Lathe Machine, Vocational Training Teacher.
Abstract: The purpose of this study is to explore the effects of virtual reality (VR) vocational training content for lathe
skills and to evaluate usability. A lathe is one of the most basic and important machines for conducting
various mechanical operations including cutting, drilling, sanding, knurling, etc. Therefore, it is necessary to
consider practice and repetition as a method for acquiring the skill to operate a lathe machine. How to
further increase operation skill must also be addressed. Opportunities to repeatedly practice using a lathe are
very limited in actual educational environments due to the expense of equipment and the risk of machine
operation. In order to overcome these limitations, we have developed a VR lathe training system and
evaluated its usability and effectiveness by working with vocational training teachers. As a result, similarity
with an actual practice environment was confirmed, and the outlook for using this VR solution in classes is
high. Furthermore, the teachers involved provided feedback to further improve the VR training system
developed.
1 INTRODUCTION
The introduction of technology to education has
increased both efficiency and effectiveness of
traditional learning methods. For instance, use of
ICT technology in education enables learning
resources to be shared as well as facilitating
cooperative learning. Furthermore, use of ICT in
education not only provides tools for improving
projects and enabling learning based on real
problems, but also introduces new curricula that can
provide more feedback to both teachers and
students, changing the education and training
environment (Bhattacharjee, Deb, 2016). Recently,
experience-oriented educational content that actively
engages learners has been expanding. To construct
experience-oriented educational content, advanced
technology such as virtual and augmented reality has
been used in educational media.
Virtual reality (VR) technology has been
evolving since its use for US military combat
training simulations in the 1970s, and recently, its
usage has further expanded to include games,
entertainment, education and other industries (Lee,
et al., 2018). In recent years, VR technology has
become more personalized and interactive due to the
evolution of computer hardware and rendering
technology. VR technology focuses on providing an
immersive experience by offering a virtual space
even more realistic than the real world or by
constructing an imaginary new world (Martín-
Gutiérrez, et al., 2017). Immersion is a key feature
of VR technology and is associated with interactivity
and visual presence (Rosemblum, Cross, 1997).
Through VR, a user interacts with many virtual
objects and experiences the same real feelings as
being in the physical world (Bae, Noh, 2014).
VR technology can be applied to education and
used as a tool to have students solve problems
occurring in the real world through simulations, or it
can be used to stimulate a learner’s interest and
promote voluntary learning motivation and
participation in learning (Freina, Ott, 2015). In the
future, if the media characteristics of VR are
considered sufficiently and content is differentiated
from the existing image media continuously, there is
a high possibility that the utilization of VR in
educational institutions and work experience fields
440
Shin, J., Jin, K. and Kim, S.
Investigation and Evaulation of a Virtual Reality Vocational Training System for General Lathe.
DOI: 10.5220/0007737304400445
In Proceedings of the 11th International Conference on Computer Supported Education (CSEDU 2019), pages 440-445
ISBN: 978-989-758-367-4
Copyright
c
2019 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
will further expand. This is because VR offers
access to areas such as the human body or outer
space that cannot be directly experienced; this also
applies for topics accompanied by great cost or risk,
such as scientific experiments, military training, and
medical practice, all of which can be experienced
under controlled circumstances through VR
simulation (So, 2016). Therefore, the future of VR is
very promising.
In general, the novelty of new technology in
education increases learning effects by attracting
learners’ interest and attention (Jang, Kye, 2007).
VR technology is expected to contribute as an
educational medium beyond merely offering a novel
effect, improving effectiveness and efficiency for
behavior-oriented learning, practical education, and
self-directed experience. In this respect, VR
technology is most suitable for vocational training
that emphasizes practical field experience, practical
training, and scenarios that are too difficult or
dangerous to construct in reality. In these contexts,
VR allows users to experience safe, low-cost
technical training without expensive machines or
devices. Accordingly, the Ministry of Employment
and Labor in Korea has been developing and
distributing VR vocational training content for
technical vocational training fields. Thirty-five kinds
of realistic virtual training content have been
developed by KOREATECH. KOREATECH
provides free VR content (machinery, electricity &
electronics, environmental, energy, safety and
construction, etc.) to both public and private
vocational training institutions and high schools for
vocational education and training. By providing this
content at no charge to public sectors, it is possible
to avoid budget duplications for purchasing training
equipment when carrying out different types of
vocational training in the same field. It also helps
develop the content available at educational
institutions. Furthermore, it increases the utilization
of VR training content.
KOREATECH has a total of 35 virtual training
modules (as of May 2018). Among these, the course
for learning to use a lathe offers skills for one of the
most basic machines in the field of manufacturing.
So, this can be considered a basic training course,
universally required for vocational training in the
technical engineering field (Park, 2013). The
purpose of this study is to discuss the necessity of a
VR vocational training system for vocational
training and education teachers in Korea. In Section
2, we describe the overall structure of the VR system
developed, and in Section 3, we present usability
evaluation results. In Section 4, we discuss the neces-
Table 1: VR/AR Vocational training content list
(KOREATECH).
Field
VR Vocational Training Content
Machinery
(11)
Turbo chiller, Hybrid vehicle, Screw-
type chiller system, Clean-diesel engine
vehicle, General purpose milling
machine, Absorption Refrigeration
Systems, Machining center ORIGIN
setup (Establishment of a reference
coordinate system), Maintenance
training for absorption chiller-heater,
Maintenance training for thermal power
plant boiler main equipment, General-
Purpose Lathe, Motor vehicle chassis
maintenance training: Steering device,
Braking device
Electricity
&
electronics
(15)
Hydraulic proportional control training
device, Control and operation &
maintenance in clean room, Wind
power generator, SMT in line system
Installation and operation &
maintenance of photovoltaic power
generator, Hydraulic elements design,
Practice of piping wiring work
Chemistry
(1)
Chemical Handling Laboratory Safety
Experience
Construction
(2)
Overhead crane safety content,
Container crane safety content
Architecture
(5)
Passive house design, Construction of
reinforced concrete buildings,
Landscape architecture, Forklift
operator test, Total station and GNSS
Materials
engineering
(1)
Shielded metal arc welding training
sity of developing and disseminating VR content in
vocational training.
2 SYSTEM COMPOSITION OF
THE VR LATHE MACHINE
The suggested VR vocational system is composed of
a base station, a head mounted display (HMD), a VR
controller, and a PC. Figure 1 shows a block
diagram of the proposed system. The base station
continues to emit an infrared laser (IR laser) after the
power is turned on. When a user holds the VR
controller and moves it, the resulting motion is
measured by a sensor consisting of an inertia
measurement unit (IMU) and an IR photo detector.
The IMU measures the rotational motion of the VR
controller, and the IR photo detector receives the IR
laser to compute the linear motion of the VR
controller. The measured translation/rotation motion
is conveyed to the PC to represent interactions with
Investigation and Evaulation of a Virtual Reality Vocational Training System for General Lathe
441
a virtual environment via a wireless communication
module. The motion analyzer receives human
motion commands and interprets them. According to
the interpreted human motion, target virtual objects
are manipulated and operated. The amount of
interaction corresponds to vibration commands
conveyed to the VR controller to drive the vibration
motor. Furthermore, the virtual environment is
displayed by the HMD according to the amount of
interaction. Therefore, a user not only visually
watches stereoscopic images through the HMD but
also feels haptic sensations via the VR controller.
Most virtual objects for the vocational content
are modeled with 3D max, and tiny objects are
captured with a 3D scanner. We applied widely-
accepted UV texture mapping to virtual objects to
increase the level of immersion. Figure 2(a) shows a
wireframe model of the virtual lathe developed, and
Figure 2(b) shows it displayed as a solid. Figure 2(c)
shows the model with a texture applied. In this study,
we positioned and rendered the textured model in a
virtual environment using Unity3D to construct
immersive VR content.
VR Controller
Vibration
motor
Motion
sensor
Wireless
Communication
module
PC
Virtual
environment
Motion
Analyzer
Wireless
Communication
module
HMD
Base
station
User
IR lasers
Motion
Input
Vibration
Feedback
Vibration
command
Motion
command
Graphic
information
Visual
Feedback
VR vocational contents
Figure 1: Block diagram of the proposed system.
In order to efficiently manage the virtual objects
in the VR content, objects were divided into avatars,
dynamic objects, and static objects. The VR
controller and stationary objects such as
backgrounds were defined as avatars and static
objects, respectively. A target device/machine that a
user wants to learn is defined as a dynamic object. A
user touches dynamic objects with a VR controller
to activate or operate them. Manipulation of a
dynamic object takes place only after a collision
between the user's avatar and the object occurs. A
simple proxy was used to efficiently detect collisions
between avatars and a target object. In constructing a
virtual environment, data management is separated
from visualization. This separation allows a user to
easily modify virtual target objects without
unintended effects. If VR vocational content is
started by a user, a virtual environment including a
target device and working hand tools is
automatically loaded with a main menu.
Figure 2: Target object, (a) wireframe model, (b) solid
model, and (c) textured model (model after texture is
applied).
The virtual lathe content developed includes two
modes: a learning and practice mode. In learning
mode, a user studies the basic concept of the lathe
including its operation principle and its parts.
Furthermore, the user learns how to operate
handwheels (cross-feed and carriage handwheels),
levers (cross-feed and half-nut levers), and dials. In
addition, the user comes to understand how to
control operation speed, etc., with the virtual lathe
content. For practice mode, we have prepared some
manufacturing processes. Figure 3 shows a
manufacturing process example. A user selects a
material and plans a process; then, he/she
manipulates wheels, levers, and spindles to control
the speed of the headstock or material to be moved.
CSEDU 2019 - 11th International Conference on Computer Supported Education
442
Figure 3: Example of a manufacturing process.
3 RESULTS
3.1 Methods
To develop usability testing criteria for our VR lathe
content for training teachers, the following was
carried out: the development of leading indicators,
correction by experts according to the scenario, and
the development of core indicators. To achieve this,
a draft questionnaire was developed through a
literature review (Ryu, J. H., Yu, S. B., 2017; Yu,
2017; So, 2016) and then revised by a team of
researchers.
Figure 4: Example of a manufacturing process.
A usability evaluation was then conducted. A
total of 8 participants joined this VR lathe content
evaluation, and all were male vocational high school
training teachers. Due to the limited scope of
training teachers who participated in summer job
training, few candidate pools were available for
testing. Most participants’ ages were 50-60 (50%) or
30-40 (25%). More than half of the participants had
a bachelor's degree and they have twenty-seven
years of lecture experience(37.5%). None of the
participants had experienced VR educational content
before. However, 37.5% of them had experience
with fragmentary or corresponding vocational
training content.
3.2 Satisfaction
Through this study, we investigated overall user
satisfaction with the VR content developed,
analyzed the usability of VR media, and evaluated
the efficiency of VR content. The evaluation
response items included wholly dissatisfied (1
point), dissatisfied (2 points), neither satisfied nor
dissatisfied (3 points), satisfied (4 points), and
wholly satisfied (5 points) according to the Likert 5-
point scale.
3.2.1 Overall Satisfaction
Table 2: Overall learning satisfaction.
Content
M
SD
Overall satisfactory in class
3.9
0.99
Likely to be useful for field
application
4.1
0.83
I would recommend it to others
3.9
0.83
I am willing to learn other kinds
of virtual reality content
4.1
0.99
I expect more classes using
virtual reality
4.3
0.71
I am willing to use virtual reality
content in the future
4.3
0.88
Total
4.1
0.95
Figure 5: Overall learning satisfaction.
The overall satisfaction score showed an average
of 4.1, so users were relatively satisfied. In addition
to lathe processing, responses for applying VR to
Investigation and Evaulation of a Virtual Reality Vocational Training System for General Lathe
443
other content in the curriculum and using VR
content in the future were highest, indicating that the
teachers had a high degree of interest in VR and
willingness to use it.
3.2.2 User Convenience and Efficiency as a
Teaching Media
We investigated the user convenience of the VR
content developed (Table 3 and Figure 6) and its
effectiveness as a teaching medium (Table 4 and
Figure 7). At first, user satisfaction for convenience
was not as high as expected. This may have been
caused by the structure of the virtual content, but
inexperience with device manipulation in general
seems to have been a major factor when considering
the main object of investigation for users in their 50-
60s. Nevertheless, the strong response indicating
users want to utilize VR technology in future classes
implies high interest in development possibilities and
utilization of VR technology regardless of the present
degree of convenience.
Table 3: User convenience.
Content
M
Is user operation easy and convenient?
3.38
Is the expression and start-up effect of
equipment appropriate?
3.25
Have appropriate sound and equipment
effects been used?
3.5
Was the graphic representation clear?
3.25
Is the meaning of the information
provided correctly understood?
3.62
Was it easy to control detailed
operations during use?
3.5
Total
3.42
Figure 6: User convenience.
Table 4: Efficiency as a teaching media.
Content
M
SD
I want to use content that utilizes
virtual reality in my class.
4.25
3.88
I think virtual reality is
appropriate as an educational
medium for class.
3.88
0.83
Total
4.06
0.85
Figure 7: Efficiency as a teaching media.
3.3 Other Comments
In the last stage of usability evaluation, teachers
suggested improvements for the VR lathe processing
training content. As mentioned above, the level of
VR content implementation available to teachers is
rather weak now, but nevertheless, they believe that
VR content can be developed further in the future.
The teachers involved pointed out specific problems
with content usage, but if these aspects were
improved, they would use our VR lathe processing
content.
“This content seems to be very suitable for
beginner safety education, operation method
explanations and so on.”
“It seems necessary to improve precision
operation. If this is improved, it is likely to be used
in actual classes.”
“I want operation to be smoother. I would like
the buttons to be fine-tuned.”
“I hope you can modify the model to the desired
dimensions.”
“You should set the work piece size, select
several bytes, and fix it on the tool stand.”
“When I set the number of revolutions, I wish I
could watch the number increase and see the
coolant coming out.”
“Segmentation is needed to practice step by
step.”
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4 DISCUSSION
In general, the educational goal of technical training
is to acquire specific skills or techniques through
repetitive learning. Techniques often refer to
proficiency in dealing with specific equipment; the
smooth use of equipment and machines is an
important educational goal. In this paper, VR
vocational training content that offers a way to
practice smoothly in a low-cost, safe educational
environment was presented, proposing educational
content with great potential. On the other hand, since
VR content may affect learners’ ethics, it is
necessary to minimize the gap between VR and
traditional learners. In addition, we need to discuss
how to adapt the role of educators according to
effective technology use.
We will need to further refine usability and
construct more diverse and clear indicators for
usability evaluation in the future. In addition, we
will increase the number of survey samples and will
systematically investigate the effectiveness,
efficiency, and satisfaction of VR vocational training
content.
ACKNOWLEDGEMENTS
This work was supported by the Technology
Innovation Program (10077367, Development of a
film-type transparent/stretchable 3-D touch
sensor/haptic actuator combined module and
advanced UI/UX) funded by the Ministry of Trade,
Industry, & Energy (MOTIE, Korea). This work was
supported by Priority Research Centers Program
through the National Research Foundation of Korea
(NRF) funded by the Ministry of Education, Science
and Technology (NRF-2018R1A6A1A03025526).
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