Mobile Augmented Reality Application for Building Evacuation Using

Intelligent Signs

James Stigall and Sharad Sharma

Department of Computer Science, Bowie State University

Bowie, MD, 20715, USA

(stigallj0813, ssharma)@bowiestate.edu

Abstract

It is critical that building patrons know how to evacuate,

in case of an emergency. Live evacuation drills are ideal

for training people to evacuate in an indoor or outdoor

setting. However, live evacuation drills are time-

consuming and costly. They could also lead to injury to

participants. Virtual evacuation training would help people

visualize evacuation procedures. Emerging research

supports augmented reality as an educational, training, and

instructional tool. Motivated by augmented reality’s

educational use and mobile technology’s ubiquitous

presence, an Android-based mobile augmented reality

application (MARA) was developed to show people how to

evacuate a building. The MARA uses the Unity3D game

engine and the Vuforia AR toolkit. This paper presents the

use of intelligent signs to illustrate its benefits to the users

during evacuation.

Keywords: augmented reality, mobile AR, MARA,

evacuation, sensory cues, simulation and modeling

1. Introduction

Augmented reality (AR) is the integration of computer-

generated elements with the real world. AR is typically

achieved through specialized hardware such as AR

eyeglasses, head-mounted displays (HMDs), and

projectors. Examples of AR include Google Street View

(featured within Google Maps) which gives users a 360°

street-level, panoramic view of the areas around the world

with symbols and texts overlaid on top of it. Another

example of AR is SixthSense: a “wearable gestural

interface” that enables users to interact with applications

via an interface projected onto a surface. That system is

composed of a projector, mirror, and camera all working

together to project virtual objects from a mobile device and

to allow the user to interact with those objects [1]. AR is

different from virtual reality because the latter completely

immerses the user within a simulated environment while

AR simply projects simulated objects onto the real-world

environment.

AR can be especially realized through mobile devices.

Mobile augmented reality applications (MARAs) combine

augmented reality with mobile devices – taking advantage

of the widespread popularity of them. Mobile AR (MAR)

may be a budding technology, but companies are finding

fruitful uses for it such as tourism and marketing [2].

Razfimahazo et al [3] discuss a MARA that uses a

technology known as pedestrian dead-reckoning (PDR) to

accurately estimate the user’s location. That application

aims to guide users through famous places by giving them

historic information through audio [3]. It is important that

MARAs feature capabilities for object detection, tracking,

registration, model rendering, and calibration [4].

Emerging research attests to AR’s usage in the realm of

education. According to Nincarean et al [5], AR gives the

student a 3D view of concepts learned in the classroom –

concepts that would be hard to visualize and conceive

without AR. Also, AR has been proven to invoke things

that students learned previously, stimulate students to

participate in the learning process, and improve

collaboration amongst students and instructors [5].

Likewise, MAR is being employed for education. MAR

blends the imagination and appeal offered by AR with the

portability offered by mobile devices. MAR allows the

student to effectively learn, at anytime and anyplace, the

same things that can be taught in the classroom [6].

Evacuation training is critical because occupants of indoor

or outdoor settings need to know how to safely and quickly

vacate those settings in case of an emergency. Beyond

being familiar with optimal evacuation routes, people need

to know what other things need be done during an

emergency situation such as securing the premises, getting

people to shelter (if needed), and administering CPR or

first aid [7].

Not properly preparing for evacuation can lead to

confusion, property damage, and injury [8]. Evacuation

training is especially needed for those occupying urban

areas which are characterized by growing populations,

congested roadways, impenetrable surfaces (which

exacerbates flooding), and compressed infrastructure [9].

Live evacuation drills containing makeshift emergency

scenarios seem to be an ideal method for evacuation

training. However, participants may find live drills to be

time-consuming. Additionally, participants may not be

fully captivated during a live drill and likely will not feel

the necessary level of panic and stress [10]. Virtual

evacuation drills, on the other hand, do not require

participants to be present on site. These types of evacuation

drills engross users, showing drill participants the best

routes to follow should an emergency break out and

978-1-943436-09-5 / copyright ISCA, SEDE 2017 October 2-4, 2017, San Diego, California, USA

helping building designers visualize improvements to

existing evacuation paths.

Audio and visual cues play an important role during

evacuation as they help guide evacuees through a building

to the exit. Good visual cues help evacuees gauge their

position relative to important points along the evacuation

path and to the exit, helping them make ideal decisions

during evacuation [11]. Audio and visual cues are

especially helpful to those with hearing and vision

impairments, invoking them to follow the cues for safe

evacuation. The Americans with Disabilities Act (ADA)

has set standards for audio and visual cues. Amongst other

requirements, audio cues must have noise levels no greater

than 110 dB measured at the alarm and visual cues must be

positioned so that they can be clearly visible to evacuees

[12].

Seeing the potential MARAs can bring to teaching

concepts to users, an Android-based MARA was built to

help users evacuate the Computer Science Building located

at Bowie State University. The application was built using

the Unity3D game engine and the Vuforia AR Toolkit

(explained in Section 3.2). Vuforia AR toolkit was also

used so that the floor plans can be juxtaposed atop their

corresponding paper-based markers. The application uses

three markers – each corresponding to a particular floor in

the building. When the user hovers a device’s camera over

one of these markers, the appropriate floor plan is

generated and is superimposed over the marker. This work

is based on a previously-built application seen in [13]

where users significantly favored the application for

evacuation training over 2D evacuation plans.

This paper discusses the MARA’s design and

development and investigates the use of intelligent signs

featured in it. Section 2 presents research work relevant to

this effort. Section 3 outlines the proposed MARA’s

implementation. The MARA’s intelligent signs are

discussed in Section 4. A test run of the MARA and its

results are presented in Section 5. The issues discovered

and research questions raised during this work are given in

Section 6. Finally, the areas for future work are given in

Section 7.

2. Related Work

Several works involve using the Android SDK (Software

Development Kit) to build MARAs. Meda et al [14] built a

MARA that translated English text into Telugu language

(one of several languages spoken in India) text. In this

Android-based application, the user takes a picture of

English text and saves it as a .jpg file. Next, the image is

given to an OCR (optical character recognition) engine that

recognizes the text. Then, the Google translation engine is

used to translate the text. Finally, the resulting Telugu text

is juxtaposed upon the English text. Parea-Tanaka et al

built a mobile application in [15] where ancient ritual

objects exhibited at the Museo de América in Madrid,

Spain are recognized through AR so that information about

them is displayed on the user’s device. Parhizkar et al [16]

designed and developed an Android-based MARA to teach

students general science. Finally, a MARA described and

evaluated in [17] sought to teach users about cultural

heritage.

MARAs have also been built for purposes other than

education and training. Such an application was built in

[18] whereas an avatar juxtaposed upon the real

environment serves a personal assistant to the user,

scheduling appointments and taking notes. Another AR-

based application built in [19] enhanced the reading

experience of a book entitled “My Vision” for adult

readers providing them with English translations (for

English-speaking or bilingual readers) shown as 2D

images, Arabic texts shown as 3D images, and virtual

buttons that readers could use to contact authors. Lastly, a

MARA was built in [20] to detect interesting video

segments by using content pre-defined by the authors,

content generated through the camera’s location and

direction, and recommendations generated from content

captured at popular locations.

MARAs used for evacuation training are discussed in a

few works. Ahn and Han [21] discuss RescueMe, an

evacuation training MARA that measures the user’s stride,

obtains the user’s location, and recommends the shortest

path to the exit. Additionally, the image labeling web

service, IQEngines, is used in [21], which allows the user

to take a picture of the room number to determine the

user’s location. The image is sent from the user’s device to

the IQEngines server, which will determine, from its

database, the room number and associated information and

sends those items back to the user. Mitsuhara et al built an

evacuation training MARA in [22] emulating real-life

situations such as rain, smoke, and fog so that the user can

get a “sense of tension” while using this application.

Lastly, Iguchi et al [23] implemented a MARA featuring

virtual children to train adult users on how to direct

children during a real-life evacuation.

3. Mobile AR Implementation

The proposed application uses three separate markers –

each corresponding to a floor in the building. When the

user place the device’s camera over one of these markers,

the appropriate floor plan is generated in 3D and is

superimposed over the marker. Each floor plan features

avatars walking along a pre-defined path at various speeds.

All of these features are discussed more in Section 3.3.

Development of the MARA involved three phases. In the

first phase, each floor of the Computer Science Building on

campus was modeled using two applications for 3D

modeling: SketchUp and 3ds Max. In the second phase, the

models were imported into the Unity3D environment. In

the last phase, the models were placed on top of their

corresponding markers and the animations and user

interaction capabilities were implemented. The MARA

was tested on an Asus tablet running the Android operating

system.

3.1 Phase I

In this phase, each floor of the Computer Science

Building was modeled in SketchUp using 3D shapes. Next,

they were imported into 3ds Max to add more 3D models

and textures. The environment was saved into a format

compatible with Unity3D, the platform used to develop the

MARA.

3.1.1 Model Creation in SketchUp

SketchUp is a software where users can create 3D

models by using lines and 3D shapes. These objects can be

scaled up and down as needed. Multiple objects can be

combined to form one object. Additionally, objects can be

colored in and textures can be wrapped around them.

SketchUp is ideal for creating building plans [24]. Thus,

the layouts for all three floors of the Computer Science

Building were created using SketchUp. Each floor was

modeled according to its real-life layout to ensure its

realism. Objects such as desks, chairs, carpeting, signs,

doors, and whiteboards were added into each floor plan.

Textures were also added wherever appropriate so that the

floor plans look realistic.

Figure 1 – The first floor of the Computer Science Building

drawn in SketchUp

Once each floor was modeled, the models were imported

into 3ds Max where they were modified so that they could

be used in Unity3D. Figure 1 shows the first floor of the

Computer Science Building in sketch up.

3.1.2 Model Modification in 3ds Max

Like SketchUp, 3ds Max is an environment where 3D

models can be created. As well as creating 3D models,

users can animate models and create animated scenes [25].

For some models, objects such as chairs, desks, tables, and

computers were deleted after they were imported into 3ds

Max so that the file sizes for each model would be small

enough to be used in Unity3D. For other models, objects

were deleted in SketchUp before they were imported into

3ds Max. Once the models were modified in 3ds Max, they

were saved .3ds files so that they can be compatible with

Unity3D. Figure 2 shows the Computer Science Building

floorplan in 3ds Max where it was tweaked.

Figure 2 – The first floor being imported into 3dsMax

3.2 Phase II

After creating and modifying the models in Phase I, the

models were imported into Unity. The models were scaled

and positioned so that they could display well in the

MARA.

3.2.1 Unity3D

Unity3D is a game engine where users can create 2D and

3D games for many different platforms. These games can

be virtual reality or augmented reality games. The games

can be created for desktop or mobile systems. Users can

integrate into their projects models, scenes, code, and user

interface objects through Unity’s Asset Store. Users can

also implement C# and JavaScript code to add robust

functionality to their games.

Unity allowed necessary objects, such as avatars, to be

imported into the proposed application. It also allowed the

application to be developed for Android systems, with the

help of the Android SDK. Unity is a dynamic environment,

letting users create animations, scale models up or down,

create 3D and 2D shapes, and wrap textures around those

shapes [26].

3.2.2 Vuforia Toolkit

The Vuforia AR Toolkit allows users to develop

MARAs for Android and iOS devices [27]. The toolkit

incorporates an AR camera that provides real-time marker

detection so that 3D models can be generated on top of a

paper-based marker. Vuforia was used as a Unity plugin.

Three markers were created, each corresponding to a floor

in the Computer Science Building. The markers were then

incorporated into Unity so that the proposed MARA can

recognize the markers when the device’s camera is aimed

towards any one of them.

3.3 Phase III

The models were incorporated within a Unity scene as

shown in Figure 3. The markers associated with the

proposed MARA were placed below the AR camera and

models were situated atop of their corresponding markers

so that they can be displayed in 3D when the camera is

pointed towards the markers.

Avatars with built-in behaviors were included on each

floor of the building as shown in Figure 4. Paths were

created within Unity for each avatar to follow towards the

exit. All avatars were given different walking speeds so

that they would do not collide with each other during

evacuation. Moving avatars featured in our project allows

the user to determine what path to take to evacuate the

building. Additionally, animated fire and smoke were

incorporated to emulate a fire emergency within the

building.

Figure 3 – Models superimposed on of their respective markers in

Unity3D

For each build, the application was saved as an .apk file.

The file was then transferred onto an Asus tablet running

the Android operating system (version 4.2.1). After

installing the .apk files on the tablet, limited testing was

done to inspect the functionality and user interface.

Figure 4 – Avatars placed within the environment

3.3.1 Intelligent Signs

During a real-life building evacuation, evacuees may

hear a blaring alarm indicating a life-threatening situation

or see flashing emergency lights guiding them out of the

building. In our proposed MARA, visual cues were

emulated to show where the exits are in the building and

how to get to them. Therefore, four intelligent signs were

conceived, explained further in Section 4: blinking exit

signs, floor arrows, photo references, and moving doors.

The buttons on the GUI (graphical user interface) were

implemented in C#. They allow the user to toggle the

intelligent signs on and off. By default, all intelligent signs

are visible. However, if the user decides that the exit signs

are not necessary, then they can be toggled off using the

corresponding button for them. The buttons were

implemented on the GUI for all the intelligent signs.

3.3.2 Smoke and Fire Simulation

The MARA features virtual smoke and fire to emulate

the real-life smoke and fire that the user may experience in

a fire emergency occur within the building. The simulated

smoke and fire were added to all three floors of the

building. Coupled with avatars exiting the building, the

smoke and fire gives the user a sense that an emergency is

occurring in the building. The simulated fire and smoke

can be seen in Figure 5.

Figure 5 – Fire and smoke in the building

4. Modeling and Implementation of

Intelligent Signs

The MARA features four different intelligent signs to

help the users determine where the exits are throughout the

building and their evacuation path to those exits. The

intelligent signs are all shown in Figure 6. The user may

use the buttons located at the bottom of the GUI display to

toggle the signs on an off as he or she sees fit.

4.1 Blinking Exit Signs

These are signs in the environment with the wording

“Exit Here!!!” shown in red letters. These signs are placed

at each exit door in the building. They were given an

animation that makes them move up and down on a loop to

give the user the impression that they are “blinking”. The

animation of blinking exit signs aim to capture the user’s

attention. Animations for each exit sign were created in

Unity’s animation tool as .anim files. The animations allow

the signs to move up and down over 15-second loops.

4.2 Blue Arrows

On each floor, there are blue arrows placed on the floor.

The purpose for the arrows are to indicate the paths

towards each exit. These signs were inspired by the floor

arrows seen in Ikea stores that direct customers throughout

their stores [28].

The texture file for the blue arrows was implemented as

a .png file using Microsoft Word. A plane was created for

the texture file to wrap around. The arrows were placed

strategically to illustrate paths to the exits without

producing visual clutter.

4.3 Photo References

Real-life photos were taken at key points along each

floor. They are incorporated into the environment to help

the user recognize his or her location in the building. The

photos at the key locations in the building can be toggled

on and off.

The photo references were created as 2D planes in

Unity. Photos of specific points were taken. The pictures

were saved as .jpg images which were wrapped around the

planes.

4.4 Moving Doors

The moving doors are the green bars indicating the

major doorways on each floor that the user will go through

to get towards the exit. These could also indicate were the

exits are. Similar to the exit signs, they were given

animations that makes them move from side to side in a

15-second loop. The animations aim to get the user’s

attention.

Figure 6 – the intelligent signs (clockwise from top left):

blinking exit signs, blue arrows, photo references, and moving

doors

5. Simulation and Results

Limited testing of the proposed MARA was done to

evaluate its features such as the toggle buttons. The buttons

were implemented so that the intelligent signs can be

toggled on and off. Initially, all of the intelligent signs are

visible. The first floor with all four intelligent signs visible

can be seen in Figure 7.

Figure 7 – the first floor with all intelligent signs visible with

the buttons in the foreground and the marker in the background

When the toggle button corresponding to the exit signs is

pressed for the first time, the exit signs disappear. This

results in all the other intelligent signs remaining visible, as

expected. When the same toggle button is pressed for the

second time, the exit signs re-appear. The first floor

without the exit signs is shown in Figure 8.

The same functionality was tested out for the photo

references. Like all the other intelligent signs, the photo

references are visible by default. If the toggle button for

the references is initally pressed, then they disappear.

Similar to what occurred with the exit signs, pressing the

toggle button corresponding to the photo references leaves

all other intelligent signs visible. If the same button is

touched again, the photo references re-appear. The

toggling of the photo references on and off can be seen in

Figure 9.

Figure 8 – the first floor without the exit signs

Figure 9 – the first floor without the photo references

6. Discussion

Some issues became apparent once this app was built.

One, it was noted that the app is slow when it ran on the

device used to test it out; this is likely due to the

“heaviness” of 3D objects being featured in this app. Two,

the avatars featured in the app contain fixed, pre-defined

characteristics (e.g. behaviors, height, arm length) that do

not reflect those of real humans. Three, the fire featured in

the app is not affected by the various material found in the

building such as the door, the floor tile, and the desks.

Four, the app was built using the Android SDK meaning

that it only works on Android devices, not devices running

other operating systems such as Windows or iOS. Lastly,

the app requires that users hold their devices towards the

markers – this could slow down the evacuation process for

those evacuating the building while using the app.

This app raises five research questions that will be

answered through a user study:

How fast can users evacuate the building using this

app?

Is the app intuitive enough for people to use?

Does the app help those who are not familiar enough

with the building?

Are the intelligent signs included in the app effective

at helping users evacuate?

Overall, do users feel that this is a useful app?

7. Conclusion

In this paper, a MARA was developed to help users

evacuate the Computer Science Building at Bowie State

University. The application was implemented for Android-

based systems using Unity3D and Vuforia. By featuring

intelligent signs acting as visual aids, it promises to be

effective at helping users determine and visualize the best

path to the nearest exit. For future work, capabilities to

detect the user’s location in real-time will be implemented

so that the user can find his or her location relative to the

nearest exit. The issues stated in Section 6 will be

investigated further and remedied. Lastly, a user study of

the MARA will be conducted to determine how effective

the intelligent signs are to users. The MARA discussed in

this paper aims not only to help users evacuate a building

but also serves as an archetype tool for future applications

assisting users to safely evacuate other types of settings.

8. Acknowledgements

The authors would like to thank the National Science

Foundation for supporting this project. This work is

supported by Grant Award number HRD-1238784.

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