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The Explosive Ordnance Disposal Robot: CEO Mission EOD
Amon Tunwannarux and Supanunt Tunwannarux
Electronics & Telecommunication Engineering Department
School of Engineering, The University of The Thai Chamber of Commerce
126/1 Vibhavadee-Rangsit Rd., Dindaeng, Bangkok 10400
THAILAND
Abstract: - This paper presents the design and development of the explosive ordnance disposal robot named CEO
Mission EOD. It is the enhanced project from the rescue robot called CEO Mission IV. The mechanical arm with the
X-ray equipment set attached for improvised explosive device inspection (IED inspection) is installed on the track
wheel type universal robot platform of the CEO Mission IV robot. The X-ray set which is composed of X-ray source
and screen is installed and plugged into the versatile controlling and monitoring system so the X-ray image can be sent
to the teleoperator control suitcase wirelessly and easily. Software and hardware interface box is developed in order to
control and get image from the X-ray set without its hardware modification. The X-ray source is installed on the top
of robot body and the X-ray screen is attached on the tip of four bar linkage mechanical arm. The position of the X-ray
screen is controlled by two servo motors which have 2 degrees of freedom. The first degree is the forward angle of
four bar linkage and the second degree is the downward linear range of X-ray screen. The maximum height of
suspicious object that the robot can inspect is 85 cm. because the design target is for the inspection of the objects
which are hidden under the cushion of motorcycle. The user friendly GUI software on the teleoperator control suitcase
is developed further from the rescue version. The X-ray control function, the disrupter ignition control function and the
X-ray image manipulating function are implemented. The number of exposed X-ray pulses is used as the control
factor of the inspection image depth. In addition, the high pressure water jet gun (disrupter) is attached in order to
destroy the IED objects. The 100 Volts high voltage is pumped up step by step for the ignition preparation in order to
achieve high security. This project is researched and developed for giving to the Royal Thai Air Force. The results are
excellent and good enough for using it in the practical applications of the EOD mission in Thailand.
Key-Words: - explosive ordnance disposal, EOD robot, IEDD robot, rescue robot, X-ray source, X-ray image screen,
high pressure water jet gun, disrupter, ignition, mechanical arm
1 Introduction In the Explosive Ordnance Disposal (EOD) or
Improvised Explosive Device Disposal (IEDD) fields,
Robotized solutions with effective sensing capabilities
properly sized with suitable modularized, mechanized
structure and well adapted to local conditions can greatly
improve the safety of personnel as well as work
efficiency and flexibility [1]. With the large number of
IEDs and Unexploded Ordnance (UXO) being
encountered during recent military operations, there
exists a need for EOD mobile robots. These robots are
predominately used for surveillance, inspection and
neutralization of these explosive threats from a safe
distance. The nature of the mission means that these
robots are prone to being damaged or destroyed [2].
Thus, the functional low cost EOD robots are needed in
both EOD and IEDD missions. Some robots called the
MARCbot, LVUSS, Packbot, Talon EOD robot, Murv-
100, Andros, Johnny5 and more are remote observation
platforms which provides safe stand off when inspecting
suspicious IEDs.
From World Robocup Rescue Robot Competition,
started in 2001 until now, many rescue robots are
invented. One of the rescue robot competition team
names “CEO Mission team” has its series of rescue
robot development. The first robot from the team called
CEO Mission I helps the victim explorers to look from
(a) (b)
Fig.1 The Explosive Ordnance Disposal Robot: CEO
Mission EOD in the real mission (a) inspecting a big
box, (b) inspecting the cushion of a motorcycle.
10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008
ISBN: 978-960-6766-63-3 433 ISSN: 1790-5117
top views or to look over partitions for making decision
of exploring route. The camera on the top of 125-cm.
high mast is used for looking over the 80-cm. high
partitions and accurately marks the locations of victims
in the competition arena [3]. Then the second robot in
this series, CEO Mission II, can solve the previous
robot’s problem which is the limitation of having only
two degrees of freedom in searching [4]. It comes with a
5-joint and 5-degree of freedom mechanical arm with a
four bar linkage which can stretch to 125 cm. long.
Many sensors are installed at tip of arm, for situation
surveillance from the high level as well as getting the
vital signs of victims easier and faster. It is controlled by
a teleoperator via the user-friendly control and
monitoring GUI program [5]. Until now, this series
robot becomes to CEO Mission IV which is designed for
real practical usages as the universal robotic platform. It
also designed with the modular concept and the concept
for reproduction and ease to maintenance. Because of
the rescue robot, CEO Mission IV, not only is the track
wheel type vehicle which is ready to move on any rough
terrain but also has the rich ports controller which can
use in several functions. So it can be easily modified to
fit several practical applications. One of the
modifications is the installation of the mechanical arm
which the X-ray equipment set attached for IEDs
inspection. Its mechanical arm is designed to work with
the big box which has the maximum dimensions up to
85 cm. high and 40 cm. deep so it can inspect the object
hidden under the cushion of motorcycle as shown in
Fig.1. Moreover a high pressure water jet gun is set up
on the robotic platform as the disrupter for destroying
IEDs. That is the main purpose and concepts of CEO
Mission EOD.
In this paper, we focus on the design and
implementation of hardware and software which is
related to X-ray set, four bar linkage mechanical arm
and high pressure water jet gun. The design and
implementation details of the CEO Mission IV universal
robot platform which has the versatile controlling and
monitoring system are not included. The rest of this
paper is structured as follows. Section two gives the
details of the hardware on the robot. In section three, the
robot mechanical arm are explained. Section four
illustrates the concept and hardware details for secured
firing of disrupter. Section five gives the details of
software on the teleoperator station. GUI of X-ray set
and GUI of ignition system are presented. Section six is
the testing results and discussions. Section seven is the
conclusion and the future work.
2 The EOD Robot Hardware Concept Our main design concept is using the simple method but
Fig.2 Block diagram of the EOD robot system (operator
side and robot side)
LCD 16*2
Serial
4 KeyPads
2 DC Motors with
Encoders of
Mechanical Arm
(for X-ray Screen)
Serial
Serial
Serial
Controlling Function
Monitoring Function
A/D 10 Bit 16 Ch.
- Battery Voltage 24 V
- Power Supply 5V
- Power Supply 6V
- Power Supply 12V
- High Voltage for
Firing Ignition 100V
Access
Point
802.11
A/G
Serial
to
TCP/IP
Module
Speed Control
of Left / Right
Locomotion
Motor and
Left / Right
Flipper Motor
Multi-channel
PWM
Signal
Controller
Switch
5 Ports
CPU1
CPU2
X-ray
Source
X-ray
Screen
Serial
X-ray Beam
Video Server1 Ch. / 4 Ch.
Video Server
3 Ch / 4Ch
Camera
x3
Serial
Interface
box
Control Relay
X-ray Set6 Relay Outputs
- Laser Pointer
- Light
- Spare Relay
- Step Voltage
Pumping up
- Gun Firing Ignition
- High Voltage
Discharge
High
Voltage
Circuit
Serial
PI Controller
for Position
Control
High Pressure
Water Jet Gun
(Disrupter)
CPU3
Encoder
L &R
WheelSerial
Yaw/
Pitch/
roll
sensors
Serial
Laser
Range
Finder
2.4GHz
5 GHz
Fig.3 Block diagram of hardware on robot (monitoring
function and controlling function)
highly effective and reliable. The block diagram of the
EOD robot system is shown in Fig.2. The robotic system
design can be divided into two sides of operations as the
operator side and robot side. All of the transmitted
controlling commands and the received monitoring
information are communicated between operator’s
computer and robot via WiFi 802.11 a or g. The operator
can switch frequency between 2.4 GHz and 5 GHz to
avoid the signal disturbance instantly. Because
monitoring function and controlling function are divided
clearly as shown in Fig.3, the hardware on robot is quite
simple and easy to understand.
10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008
ISBN: 978-960-6766-63-3 434 ISSN: 1790-5117
2.1 Monitoring Function From the top half of Fig.3, it shows the robot hardwares
which work as the monitoring function. The monitoring
informations are composed of the data from all sensors
on the robot, audio/video from 3 cameras. teleoperator
can see four video with image size of 324x248 and 30
frames/sec in real time. For fast and real time
processing, most of monitoring data will be sent to
compute at the computer on the teleoperator side such as
the scanning data from laser range finder, the odometer
encoder data and yawn/pitch/roll sensor data. There are
three CPUs on the robot main board. They communicate
with each other via serial port. The CPU1, 40pins,
MCS51, is assigned for collecting all sensor data such as
battery voltages, all power supply voltage, high voltage
for firing and compass/pitch/roll angle of robot body.
The CPU3, 20 pins, MCS51, is used only for counting
the encoder pulses of left/right robot wheels. In addition,
the CPU1 also handles 4 key pads and 16 x 2 characters
LCD display which is used for maintenance and testing
at robot side.
2.2 Controlling Function From the bottom half of Fig.3, it shows the robot
hardwares which work as the controlling function.The
controlling commands are composed of all commands
that control the locomotion control, the robot’s device
on-off, the multi-joint mechanical arm movement, X-ray
set manipulation, the ignition preparation and the firing
control. The CPU2, 40 pins, MCS51, is set up for all
different types of control. The left/right flipper control
and speed control for locomotion need four PWM
signals so the multi-channel PWM controller is used for
interfacing. Because the multi-joint mechanical arm has
to hold the X-ray screen in long range, the driving
motors should be powerful enough. So we decided to
implement the PI controller for controlling two powerful
dc motors of mechanical arm. To avoid the X-ray set
modification, we studied the communication protocol of
X-ray equipment set and used CPU2 to simulate
commands for controlling X-ray sets via the serial
interface box. So we can control the number of exposing
X-ray pulses and get the X-ray image from its screen.
The image will be sent to video server and transmitted to
the operator via access point.
3 The Robot Mechanical Arm The mechanical arm is composed of three joints and one
sliding guide. Because the four bar linkage technique is
used, the angles of three joints are controlled by only
one base joint angle. This design reduces the number of
controlling point. Fig.4 shows the mechanical arm from
home position to the inspecting position. This arm has
(a) (b) (c)
(d) (e) (f)
Fig.4 Multi-joint mechanical arm with 2 degrees of
freedom in variety positions
Fig.5 The robot with dimensions and the maximum size
of object it can inspect (unit is mm.)
only two degrees of freedom. The first one is used for
spreading arm out as shown in Fig.4 (a-c). The second
one is used for sliding the X-ray screen down as shown
in Fig.4 (d-f). A powerful dc gear motor is installed
directly for the base joint angle driving. Another dc gear
motor, which is installed at base, works with sling and
some pulleys for achieving the mechanical advantage
and best motor position. This arm is designed to inspect
the big box which has maximum size of 85 cm. high and
40 cm. deep. Fig.5 shows the dimensions of the robot
and the maximum size of object the robot can inspect.
10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008
ISBN: 978-960-6766-63-3 435 ISSN: 1790-5117
With the long segment of arm, it can inspect the objects
which are hidden under the cushion of motorcycle.
4 The Hardware for Secured Firing of
Disrupter In this project, the 20 mm. calibre disrupter is used.
Because the disrupter is the high pressure water jet gun
which has a lot of power of destroying, the secured
firing is required. Our secured design concept is the
more difficult ignition, the more secured firing. The
secured ignition system comprises of components as
shown in the block diagram of Fig.6. Each step boosting
command from CPU2 will enable high voltage boost up
circuit to increase 20 Volts per step and store energy in
capacitor tank. It needs to pump up five to six times in
order to reach 100 Volts to be ready to ignite. Firing
command from CPU2 is required again by pressing with
both hands at operator side. However CPU2 will
automatically command discharge energy from tank
after 15 seconds of voltage pumping.
Fig.6 Block diagram of secured ignition system of
disrupter
5 Software on Teleoperator Station For USAR tasks, an effective user interface (UI) must be
centered on providing the human operator sufficient
information to make correct decisions about future
actions of the robot at the required level of decision-
making [6]. The user must be able to easily monitor the
robot orientation, location and power, operate various
equipments such as cameras, lights and gripper on-board
and precisely control robots movements as well as
receive images from cameras [7]. Thus, the software on
the teleoperator station is one of challenging research
fields. Due to this CEO Mission EOD robot is developed
further from our previous version of CEO Mission IV
which was designed for USAR tasks, this effective UI
concept is also considered. In this paper, we will
illustrate only the software involving the control and
monitoring of X-ray set and disrupter firing system.
1525
(2) X-ray
Pulse
Number
(3) drag-drop controland monitor displayfor mechanical arm
(1) X-ray Image
Fig.7 Graphic user interface (GUI) of the EOD robot
which shows the X-ray image (1), the number of
controlling exposed X-ray pulses (2) and drag-drop
control and monitoring display for four bar linkage
mechanical arm (3)
99.8
15
Fig.8 Graphic user interface (GUI) of the EOD robot
which shows the pumped up voltage display in the gun
firing system (1) and video from front camera which has
the laser point on the firing target (2)
5.1 Control / Monitoring Software for X-ray set The method of determining tip position in 2D
coordinating system to control the movement of this
mechanical arm is implemented in this software. The
angles of each link are calculated from the tip position
by using inverse kinematics analysis [5][8][9]. The
Graphic User Interface (GUI) of the EOD robot which
shows the X-ray image, the number of exposed X-ray
pulses and drag-drop control and monitoring display for
the four bar linkage mechanical arm are shown in Fig.7.
The user-friendly control and monitor GUI is developed
for easier usage. By clicking the determined target point
or dragging the tip of the mechanical arm on screen to
the desired target, the robot will move its arm to the pose
as seen on the GUI screen. The angles of each joint are
calculated and sent to all joint servos simultaneously in
order to move the mechanical arm to the desired position
10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008
ISBN: 978-960-6766-63-3 436 ISSN: 1790-5117
[5]. The operator can also use the joystick to control the
movement of mechanical arm and the locomotion of the
robot. The X-ray image which has resolution up to
648x496 can be edited and saved to desired location.
Operator can control number of expose X-ray pulse by
adjusting the slide bar or key number in the filled box.
5.2 Control/Monitoring Software for Ignition
System The graphic user interface of the EOD robot which
shows the pumped up voltage display in the gun firing
system and video from the front camera which has the
laser point on the firing target is shown in Fig.8. Video
from three cameras can be displayed at the same time or
selected for single display. However the control system
does not support the disrupter pan and tilt because there
is quite high reaction force when it is firing.
The software on operator side is installed on the
notebook computer which is set up in the teleoperator
control suitcase as in Fig.9. In this mobile case, the UPS
system with two 7 AH batteries can operate for 7 hours
and work in the field situation. Block diagram of the
teleoperator control suitcase is illustrated in Fig.2.
Fig.9 The operator’s mobile control suitcase with battery
included
6 Testing Results and Discussion The CEO Mission EOD robot were built as design and
tested with different manner as shown in Fig.1 In this
figure it shows how the robot can inspect things inside
the big box and cushion of motorcycle. In Fig.10, all
apparatus on robot platform are specified. The results of
inspection of the suspicious box in Fig.10 show in
Fig.11 (b) and (c) and the real IED objects inside the box
are shown in Fig.11 (a). The difference between the X-
ray image (b) and (c) is controlled by the number of X-
ray pulses which we set to expose. The more number of
pulses we expose, the deeper X-ray image we get. We
designed and developed the controller of X-ray set in
Fig.10 All apparatus on robot’s platform
(a)
(b) (c)
Fig.11(a) The IED objects in the suspicious box (cell
phone, electric wire, electronic board inside
and explosive device C4)
(b) The X-ray image when the number of expose
pulse is 10
(c) The X-ray image when the number of expose
pulse is 20
order to operate with X-ray sets from Thai Royal Air
Force without their hardware modification. So it is easy
and no expert requirement to set it up and remove it out
from our robot. Because the total weight of the EOD
robot is about 60 kg and its mechanical arm is quite long
even being home pose as shown in Fig.12, we designed
the mechanical arm to be able to disassemble from robot
platform before transporting to operation place. The
lock system between the X-ray set, the mechanical arm,
and robot platform is designed to be the toolless type.
10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008
ISBN: 978-960-6766-63-3 437 ISSN: 1790-5117
Fig.12 The robot with home pose of mechanical arm and
the maximum size of object it can inspect (unit is mm.)
Only two hands of one operator can assemble and
disassemble mechanical arm, X-ray source and screen in
30 seconds.
In the field operation, the teleoperator control
suitcase can operate for 4 hours if use one battery and
for 7 hours if use two batteries. So the bottle neck of
operation time is on the robot. The operation time of this
robot depends on its mission. If the robot has to run at
all time on roads, rough terrain and stairs, it will be able
to operate for 1 hour. But if the robot runs to the
suspicious object and spends most of the time for
inspecting IEDs, it experiences for 2 – 3 hours. For its
EOD mission, this looks like long enough.
The communication range of the robot is about 100
meters line of sight. That is fair range, which will be
improved in the next version. The full speed of running
on road is 53 cm/s or 1.9 km/hr. This speed is good
enough for its mission because it usually work in rough
terrain and not necessary to travel in far distance.
Because most of terrorist operations in our country
use cell phone as bomb remote controller, the
frequencies of their operations usually are 900MHz,
1800MHz and 1900MHz. Therefore the design of two
frequency system in this robot is very useful and
practical in our country mission. The first operation of
officer is disturbing terrorist frequency with jammer. It
sends and sweeps the jamming frequency from 3 GHz
down to 400 MHz. In the operation of CEO Mission
EOD, operator could switch the communication
frequency to 5 GHz for avoiding the jammer.
7 Conclusion and Future Work The CEO Mission EOD robot was designed and
implemented. The robotic system has been described
especially the things relate to X-ray set and disrupter.
The result of this work is close to be a final prototype
design, which is currently undergoing extensive testing
to characterize its capabilities. Some of these tests
include robot characteristics such as robot speed and
mobility, robot weight and size, communication range
and battery longevity as well as operating among
jammers. Its performances were observed to be
excellent. For further work, mechanical arm in different
sizes and different situations should be implemented, for
example the arm for inspecting small box in the public
phone cabinet.
Finally, we would like to thanks the University of the
Thai Chamber of Commerce, UTCC who supports the
research grant and the Thai Royal Air Force who gives
the problem of this mission and all knowledge about
EOD/IEDD.
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10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008
ISBN: 978-960-6766-63-3 438 ISSN: 1790-5117