<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Tool with Digital Twin for Monitoring Forest Fire on Mountain Trail through UAV</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Chang-Hui Bae</string-name>
          <email>chbae@gnu.ac.kr</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ji-Won Jeong</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Seongjin Lee</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="editor">
          <string-name>Forest Fire, UAV, Flight Plan, Digital Twin,</string-name>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>1st International Workshop on Intelligent Software Engineering</institution>
          ,
          <addr-line>De-</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Dept. of AI Convergence Engineering Gyeongsang National University Jinju</institution>
          ,
          <country>Republic of KOREA</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Dept. of Aerospace and Software Engineering Gyeongsang National University Jinju</institution>
          ,
          <country>Republic of KOREA</country>
        </aff>
      </contrib-group>
      <fpage>6</fpage>
      <lpage>8</lpage>
      <abstract>
        <p>A tool for creating flight plan is needed to monitor forest fires on mountain trail through UAV. Existing tools for crating lfight plan for forest fires monitoring are created in a file format applicable to Ground Control Station. Additional time and manpower is consumed to apply the flight plan to the UAV. This paper presents AFPC(Automatic Flight Plan Creation), a tool that can automatically apply flight plan of UAV through digital twin. AFPC uses digital twins, so it can be easily expanded to enable UAV state monitoring and prediction using artificial intelligence. The evaluation of the AFPC compares the time and resources spent applying the flight plan created by the tool to UAVs with the related work.</p>
      </abstract>
      <kwd-group>
        <kwd>Mountain</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        A forest fire that fails to respond in the initial stage grows
into a large forest fire using surrounding leaves and
vegetation as fuel. Since large-scale forest fire cause great
damage to surrounding private houses and nature, early
detection and response is important. UAVs are suitable
for forest fire surveillance because they can
reconnaissance over large terrain. Fig. 1 shows the analysis by
the Korea Forest Service of the causes of forest fires that
occurred in Korea from 2012 to 2021 [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. The forest fire
that occurred in South Korea were caused by artificial
factors with a statistical probability of about 70%, and
about 34% of them were forest fires caused by trackers.
      </p>
      <p>Based on this, the existing paper presented a tool for
automatically generating a flight plan based on a mountain
trail for forest fire monitoring through UAV. However,
since existing tool creates a file in the format that can be
used as the input to the GCS (Ground Control Station),
time and resource are required to apply flight plans to
UAVs.</p>
      <p>
        This paper presents AFPC (Automatic Flight Plan
Creation), a tool that can automatically apply flight plan of
UAV through digital twin. AFPC combines digital twin
with existing flight plan creation tool, allowing UAVs to
perform automatically created flight plan. AFPC uses
digital twins, so it can be easily expanded to enable UAV
state monitoring and prediction using artificial
intelligence. The digital twin used in AFPC was constructed by
adding a DB module to the Ditto [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]-based digital twin
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Background</title>
      <sec id="sec-2-1">
        <title>2.1. Unmanned Aerial Vehicle</title>
        <p>
          An Unmanned Aerial Vehicle (UAV) is an aircraft that
does not have a pilot on board and has a wide range of
activities. UAVs consists of various hardware devices
necessary for flight and software for automatic flight and
state control. Due to their ability to provide eficient
infrastructure and a wide range of services, UAVs are
increasingly being recognized as a major component of
the next generation of smart cities [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ].
        </p>
        <p>UAVs can be used for reconnaissance missions for
forest fire monitoring. Since large-scale forest fires cause
property and personnel injury, it is important to detect
and respond to forest fires early through UAVs. UAVs can
perform reconnaissance missions for forest fire detection
through devices attached to UAVs while traversing the
set flight plan. The flight plan of the UAV can be set using
the flight plan creation tool. The created flight plan can
be applied through GCS. GCS is software for monitoring
and controlling UAVs and includes the function to apply
lfight plans to UAVs.</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Digital Twin</title>
        <p>
          Digital Twin was first introduced by Grieves [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ] in 2003
and is a technology that connects physical and virtual
spaces. Currently, digital twin is recognized as the core
technology of the 4ℎ industrial revolution, and
monitoring and simulation can be performed by virtualization
things in physical space in virtual space. Recently,
research on digital twin technology has been actively
pursued as various fields such as big data, ICT (Information
and Communications Technology), and cloud computing
have advanced [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. Digital twin is defined as a
nextgeneration simulation technology because it performs
monitoring and simulation based on real-time state data
of things in physical space.
        </p>
        <p>
          The digital twin framework provides functions such
as data communication and object management. it can
enhance the reusability, compatibility, and
maintainability of digital twins. Ditto [
          <xref ref-type="bibr" rid="ref2">2</xref>
          ], provided by the Eclipse
Foundation, is a representative digital twin framework
based on open source. Ditto is a framework that provides
the functions of a digital twin, and provides functions
such as registered things management, communication,
and security.
        </p>
        <p>However, Ditto has a limitation of registering up to
a maximum of 511 objects and the communicable data
size is limited to 100KB. In addition, since Ditto does not
manage past data, the Ditto used in this paper is used in
conjunction with an additional DB module.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Related Work</title>
      <p>
        Ditana et al. [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] have presented a system that can detect
forest fires early using UAVs and artificial intelligence.
The UAV scans the forest using optical and thermal
cameras, and the AI algorithm analyzes the data collected
by the drone to detect forest fires, which can then be
reported to ground firefighters for appropriate action. Ko
et al. [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] proposed a system that uses a UAV equipped
with a thermal camera to detect high-temperature areas,
process the data in real-time, and provide information
that can be used for forest fires prevention. The UAV can
transmit information about high-temperature areas to
a base station, which can help prevent forest fires from
occurring early on. These two works focus on detecting
forest fires rather than creating UAV flight plan to detect.
      </p>
      <p>
        Han et al. [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] and Joo et al. [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] presented a tool to
create a flight plan for UAVs that make a reconnaissance
around the Mountain trail to monitor forest fire. The
presented flight plan creation tool creates a flight plan
ifle in the format applicable to the GCS. Files generated
by existing tool have to be applied to UAVs through GCS,
which requires additional time and manpower. To reduce
the additional time and resource for applying flight plan
to UAVs, a tool is need to automatically apply flight plan
to UAVs.
      </p>
    </sec>
    <sec id="sec-4">
      <title>4. Solution</title>
      <p>
        This paper presents AFPC (Automatic Flight Plan
Creation), a tool that can automatically apply flight plans
for forest fire surveillance to UAVs. AFPC directly
transmits flight plan information to the digital twin instead
of creating a flight plan file that can be applied to GCS
by applying digital twin to existing flight plan creation
tools. The flight plan stored on the digital twin then
allows UAVs to automatically read. The digital twin used
in AFPC was constructed by adding a DB module to the
Ditto [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]-based digital twin framework to improve data
transmission performance. The UAV used an onboard
computer, a Raspberry Pi, to communicate with the
digital twin. AFPC uses digital twins, so it can easily be
extended to enable state monitoring and AI-based
prediction while UAVs perform flight planning. Fig. 2 shows the
overall structure of the system to which APFC is applied
and the operation process of AFPC is as follows:
1. First. The user sets up a flight plan based on the
      </p>
      <p>Mountain Trail through APFC.
2. Second. The assigned flight plan is transmitted
to the digital twin.
3. Third. The UAV reads the flight plan stored in the
digital twin through the Raspberry Pi and applies
it to the UAV system.</p>
      <p>AFPC not only applies the flight plan in the
environment to UAV, but also can collect UAV’s state data. This
allows users to periodically manage the UAV through the
digital twin included in AFPC. For example, users can
verify whether the UAV is flying the flight path correctly
and predict and handle errors that may occur in the UAV
in advance. The method of monitoring UAV through
AFPC is as follows:
1. First. The state of the UAV is transmitted to the</p>
      <p>Raspberry Pi.
2. Second. The Raspberry Pi transmits the state of
the UAV to the digital twin.
3. Third. The digital twin analyzes and responds to
the current state of the UAV through user-defined
algorithms.
4. Four. The Raspberry Pi applies the UAV control
commands received from the digital twin to the
actual UAV.</p>
      <p>In additionally, the flight plan creation in previous
work involved randomly creating waypoints along a
specific path. In contrast, APFC applies an algorithm that
reduces the number of randomly created waypoints based
on distance. As a result, flight plans created by APFC
require fewer waypoints to reach their destination
compared to existing creation tool.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Evaluation</title>
      <p>The environment used for the implementation and
experiments of AFPC consisted of a PC with Windows 10
operating system, CPU Intel i7-11700, and 32GB RAM.
Raspberry Pi 4B module was used as the onboard system
of the UAV. In addition, Ditto 2.2V was used, which was
built in a Docker environment.</p>
      <p>The evaluation of AFPC compares the time and
resources spent applying the flight plan to UAVs with
related work. (a) in Fig. 3 compares the size of the flight
plan file created by AFPC with the size of the flight plan
ifle created by the related work. As a result of the
comparison, AFPC created a file of about 4.2KB size when
it created a flight plan containing about 110 waypoints,
while related work created a file of about 33.8KB size.
When using AFPC to create flight plans, flight plans can
be applied to UAVs with approximately 8 times smaller
data than related work.</p>
      <p>(b) in Fig. 3 compares the time it takes to create a flight
plan and apply the created flight plan to the UAV. As a
result of the comparison, both AFPC and related work
took approximately 0.2 seconds to create a flight plan.
However, applying the created flight plan to UAVs took
approximately 0.65 seconds for AFPC and approximately
5 seconds for related work. In summary, APFC could
reduce time and resource consumption about 6-8 times
compared to related work.</p>
      <p>
        Additionally, We evaluate the AFPC through
simulation that the UAV flies according to the flight plan
crated by the AFPC. The simulation is performed in the
Gazebo [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] environment, which is mainly used for
aircraft. Fig. 4 shows that the UAV is flying according to
the flight plan set in the Gazebo. (a) in Fig. 4 shows the
applied to the UAV through AFPC, and (b) shows the
UAV flying in the simulation environment along the set
lfight path. As a result of the evaluation, it was confirmed
through simulation that the UAV flew normally according
to the flight plan set through AFPC.
      </p>
    </sec>
    <sec id="sec-6">
      <title>6. Conclusion</title>
      <p>Reconnaissance missions for forest fire surveillance using
UAVs are important for early detection and response to
forest fires. For forest fire detection, tool is needed to
create flight plans for UAVs based on mountain trails.
However, existing tools require application to UAVs via
GCS, which requires additional time and manpower. This
paper presents an AFPC that combines digital twins to
automatically apply flight plan to UAVs. As a result of
evaluating AFPC, APFC can reduce the time and resource
consumption of about 6 to 8 times for applying flight plan
to UAVs compared to related work. The simulation results
evaluated that the UAV in the simulation flies correctly
according to the flight plan applied through APFC.</p>
    </sec>
    <sec id="sec-7">
      <title>7. Acknowledgement</title>
      <p>This study was carried out with the support of ‘R&amp;D
Program for Forest Science Technology (Project No.
2021344A00-2223-CD01) provided by Korea Forest
Service(Korea Forestry Promotion Institute). Following are
results of a study on the “Leaders in Industry-university
Cooperation 3.0” Project, supported by the Ministry of
Education and National Research Foundation of Korea
(No. 202209720001)</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          <article-title>[1] Korea forest service, “causes and efects of forest ifre</article-title>
          ,”,
          <year>2022</year>
          . URL: https://www.forest.go.kr/kfsweb/ kfi/kfs/cms/cmsView.do?mn=NKFS_
          <volume>02</volume>
          _
          <fpage>02</fpage>
          _
          <fpage>01</fpage>
          _
          <fpage>03</fpage>
          _
          <fpage>01</fpage>
          &amp;cmsId=FC_
          <fpage>001153</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2] ditto,
          <year>2022</year>
          . URL: https://www.eclipse.org/ditto.
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>N.</given-names>
            <surname>Koenig</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Howard</surname>
          </string-name>
          ,
          <article-title>Design and use paradigms for gazebo, an open-source multi-robot simulator</article-title>
          ,
          <source>in: 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566)</source>
          , volume
          <volume>3</volume>
          ,
          <year>2004</year>
          , pp.
          <fpage>2149</fpage>
          -
          <lpage>2154</lpage>
          vol.
          <volume>3</volume>
          .
          <source>doi:1 0 . 1 1 0 9 / I R O S . 2 0</source>
          <volume>0 4 . 1 3 8 9 7 2 7 .</volume>
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>A. R.</given-names>
            <surname>Singh</surname>
          </string-name>
          ,
          <article-title>How drones are crucial for smart cities</article-title>
          ?,
          <year>2018</year>
          . [online] Available: https://www.geospatialworld.net/blogs/how
          <article-title>-drones-are-crucial-for-smartcities/.</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>M.</given-names>
            <surname>Grieves</surname>
          </string-name>
          ,
          <article-title>Digital twin: manufacturing excellence through virtual factory replication</article-title>
          ,
          <source>White paper 1</source>
          (
          <year>2014</year>
          )
          <fpage>1</fpage>
          -
          <lpage>7</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <given-names>Y.</given-names>
            <surname>Lu</surname>
          </string-name>
          , C. Liu, I. Kevin,
          <string-name>
            <given-names>K.</given-names>
            <surname>Wang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Huang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>X.</given-names>
            <surname>Xu</surname>
          </string-name>
          ,
          <article-title>Digital twin-driven smart manufacturing: Connotation, reference model, applications</article-title>
          and research issues,
          <source>Robotics and Computer-Integrated Manufacturing</source>
          <volume>61</volume>
          (
          <year>2020</year>
          )
          <fpage>101837</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>D.</given-names>
            <surname>Kinaneva</surname>
          </string-name>
          , G. Hristov,
          <string-name>
            <given-names>J.</given-names>
            <surname>Raychev</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Zahariev</surname>
          </string-name>
          ,
          <article-title>Early forest fire detection using drones and artificial intelligence</article-title>
          ,
          <source>in: 2019 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO)</source>
          ,
          <year>2019</year>
          , pp.
          <fpage>1060</fpage>
          -
          <lpage>1065</lpage>
          .
          <source>doi:1 0 . 2 3</source>
          <volume>9 1</volume>
          <fpage>9</fpage>
          <string-name>
            <surname>/ M I P R O</surname>
          </string-name>
          .
          <volume>2 0 1 9 . 8 7 5 6 6 9 6 .</volume>
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <surname>K.</surname>
          </string-name>
          <article-title>gwon mo, K. woo yeon, K. jae soo, P. hyun min, K. kyu chang, Implementation of laceration drone to detect the cause of fire early</article-title>
          ,
          <year>2022</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [9]
          <string-name>
            <given-names>M. G.</given-names>
            <surname>Han</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J. W.</given-names>
            <surname>Jeong</surname>
          </string-name>
          ,
          <string-name>
            <given-names>E. T.</given-names>
            <surname>Choi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. J.</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <article-title>Applicability analysis of uav path generation tool for monitoring forest fire on mountain trail</article-title>
          ,
          <year>2022</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10]
          <string-name>
            <given-names>G. H.</given-names>
            <surname>Joo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M. G.</given-names>
            <surname>Gang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N. Y.</given-names>
            <surname>Goo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J. S.</given-names>
            <surname>Park</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H. W.</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. J.</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <article-title>Automatic mission file generation scheme for wildfire detection drones system</article-title>
          ,
          <year>2021</year>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>