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Abstract—This paper describes a design and
development of an Autonomous Underwater
Vehicle (AUV). AUV are robotic submarines that
are a part of the emerging field of autonomous and
unmanned vehicles. This project shows the design
implementation of an AUV as a test bed platform
for a variety of research in underwater technologies
especially involving small-scale, surface water and
low-cost underwater robots. The general design
and its consideration are well discussed in this
paper. The AUV prototype has been developed by
SolidWork. It will have a fixed mechanical system
and body, having a modular electronic system that
allows development of various controllers. The
controller and motors has been tested in small
scale surface water and the result is encouraging.
Some of the factor affecting the AUV performance
is also elaborated for future research in this area.
Keywords- Autonomous Underwater Vehicle, Underwater
Robotic Vehicle, Unmanned Vehicle.
I. INTRODUCTION
obotic submarine i.e. an Autonomous Underwater
Vehicles (AUV) is very challenging research area and
valued for both their expand ability and replace ability
because they can be deployed in hazardous environments
without risking human divers. This emerging field is very
economical as AUVs has the potential for cheap scalability
makes it ideal for large scale and long term data collection
tasks. An Autonomous Underwater Vehicle (AUV) is a
robotic device that is driven through the water by a
This work was supported in part by the UNIC under UTeM’s Short-
Term Grant PJP/2006/FKE (7) – S205.
M. Shahrieel M. Aras is a lecturer in the Mechatronics Department,
Faculty of Electrical Engineering (Email:shahrieel@utem.edu.my).
H.A Kasdirin is a Head of Control Department in Faculty of Electrical
Engineering (email: hyreil@utem.edu.my).
M. Herman Jamaluddin is a lecturer in the Mechatronics Department,
Faculty of Electrical Engineering UTeM (email: herman@utem.edu.my).
M. Farriz Basar is a teaching engineer in Faculty of Electrical
Engineering and currently on study-leave (email: mfarriz@utem.edu.my).
propulsion system, controlled and piloted by an onboard
computer, and maneuverable in three dimensions [1]. This
level of control, under most environmental conditions,
permits the vehicle to follow precise preprogrammed
trajectories wherever and whenever required [1].
Nowadays, many universities all over the world are doing
research on Autonomous Underwater Vehicles (AUV). The
task of the designers was to develop a concept for an AUV
that is smaller and cheaper than existing ones. Sensors on
board the AUV sample the ocean as the AUV moves
through it, providing the ability to make both spatial and
time series measurements [2]. Sensor data collected by an
AUV is automatically geospatially and temporally
referenced and normally of superior quality [3]. Multiple
vehicle surveys increase productivity, can insure adequate
temporal and spatial sampling, and provide a means of
investigating the coherence of the ocean in time and space
[4]. The development of the AUV is presented as an
example of the implementation process for a mechatronic
product.
In this paper, firstly, it will explain the AUV basic design
and development by using computer-aided software called
SolidWork and some descriptions on the design concept
which has been implemented. Furthermore, the later section
discussed the step-by-step development of the AUV and it
will end with discussion of some factor that will affect the
AUV design and development especially the AUV
performance in the deep-sea or underwater.
II- AUV DESIGN
First, to design an AUV, the project process should be
identified as shown in Figure 1. It can be classified into
several stages. The first stage concentrates on the design
concept of the AUV. The later stages can be described in
two sections; the first section is the development of the
mechanical structure. Thus, computer-aided software such
as the SolidWorks software is used to draw and animate the
AUV that are proposed and expected. Another section is the
development of the internal and external electrical design of
the AUV. The final stage is concluded with its testing,
appraisal and minor adjustment of the project. The overall
design flows of the design and development of AUV is
shown in Figure 1.
Design and Development of an Autonomous
Underwater Vehicle (AUV-FKEUTeM)
M Shahrieel M Aras, H A Kasdirin, M Herman Jamaluddin, M Farriz Basar, Fakulti Kejuruteraan
Elektrik, UTeM
Proceedings of MUCEET2009
Malaysian Technical Universities Conference on Engineering and Technology
June 20-22, 2009, MS Garden, Kuantan, Pahang, Malaysia
MUCEET2009
R
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Figure 1: Design and construction of project
III GENERAL DESIGN OF AN AUV
There are several aspects in AUV electrical and
mechanical design need to be looked at closely so that the
design will be successful. In order to design any underwater
vehicle AUV, it is essential or compulsory to have strong
background knowledge, fundamental concepts and theory
about the processes and physical laws governing the
underwater vehicle in its environment. Therefore, the major
design aspects that need to be considered [3] are identifying
hull design, propulsion, submerging and electric power.
Figure 2 is the method that we are using to design an AUV.
Figure 2: Concepts of AUV
A. Hull Design
An AUV must provide a pressure hull to house its
components in a dry, watertight environment. The hull must
allow components to be easily accessible and maintainable,
as well as allowing for modularity in case of future changes
or additions [1]. As well as being light and strong, the hull
should also be corrosion resistant as it will be subjected to a
harsh saltwater environment. Spherical hulls offer the best
structural integrity; however, the shape inhibits the efficient
use of the space available as most components and systems
are rectangular in shape. So, cylindrical hulls provide the
best alternative, comprising high structural integrity and a
shape conducive to the housing of electronic components.
B. Submerging
In the case of an underwater vehicle, since the volume of
the vehicle remains constant, in order to dive deeper, it must
increase the downward force acting upon it to counteract
the buoyant force. It can accomplish this either by
increasing its mass using the use of ballast tanks or iron
load and or by using external thrusters.
Ballasting is the more common approach for submerging.
This method is mostly mechanical in nature and involves
employing pumps and compressed air to take in and remove
water as shown in Figure 2. The alternative is to use
thrusters that point downwards. This is a much simpler
system, but is quite inefficient in terms of power
consumption and not really suited at great depths. To
reduce the size of ballast tanks or the force required by
thrusters for the process of submerging, AUVs are usually
designed so as to have residual buoyancy. That is, the
weight of the vehicle is made to be more or less equal to the
buoyant force. The ability of an object to float depends on
whether or not the magnitude of the weight of the body is
greater than the buoyant force.
C. Propulsion
Some sort of propulsion is required on all AUVs and is
usually one of the main sources of power consumption.
Most AUVs use motors for propulsion due to the scarcity
and cost of alternative systems. The location of the motors
affects which degrees of freedom can be controlled. The
positioning of the motors can also affect noise interference
with onboard electronic components, as well as propeller-
to-hull and propeller-to-propeller interactions. Propeller-to-
hull and propeller-to-propeller interactions can have
unwanted effects in the dynamics of an AUV. When
travelling at a constant speed, the thrust produced by the
motors is equal to the friction or drag of the vehicle[1], that
is
Thrust = Drag = 0.5ρs2ACD (1)
where ρ is the water density, s is the speed, A is the
effective surface area and CD is the drag coefficient. Power
consumption for the propulsion system increases
dramatically as the speed of the vehicle increases. This is
because the thrust power is equal to the product of the thrust
and the speed, meaning thrust power is a function of speed
cubed [1],
Thrust Power= Thrust x s = 0.5ρs3ACD (2)
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Therefore, because of an AUV’s limited energy supply, it
must travel at a speed that does not draw too much power,
but at the same time does not take too long to complete its
mission. Obtaining the ideal speed becomes an optimization
problem.
D. Electric Power
Electric power is commonly provided via sealed
batteries. The ideal arrangement of batteries is to have them
connected in parallel with diodes between each one to allow
even discharge and to prevent current flow between
batteries. Fuses or other protective devices should also be
used to prevent excessive current flow in case of short
circuits occurring or components malfunctioning. The
restrictive nature of power on AUVs influences the types of
components and equipment that can be utilized.
Components and equipment should be chosen so as to draw
as little power as possible in order to allow the batteries to
provide more than enough time for the vehicle to complete
its mission.
IV- RESULTS
The AUV can be designed in 3D by using computer-
aided software and hence, the SolidWorks is 3D mechanical
CAD (MCAD) software used. The software enables the user
to play around to make any changes or modification of the
model an AUV. Actually this design is finalized after a
selected the suitable and best design. Figure 3 is the AUV
that design using SolidWorks software. In addition, by
using the tools given, the modification could easily handle
and Figure 4 shows that the design can be separated. Early
design we expect only 2 place can be open so that we can
modified or maintenance our AUV.
Figure 3: Simulation design using SolidWorks
Figure 4: 3D Design using SolidWorks
A. Skeletal Frame
The primary structure of the design is making the
mechanical parts especially the skeletal frame. The skeletal
frame as shown in Figure 5 and Figure 6 is made from
aluminium, chosen especially for its lightweight
characteristic as well as its resistance to corrosion which
helps protect the frame against the harsh saltwater and
chlorine environment in which it is subjected to. As well as
supporting the two hulls and four motors, the structure of
the frame allows for the simple mounting of external
devices and components. The design took into account the
potential need for additional components in the future and
for that reason ample space is available on the frame. The
symmetrical and structurally simple nature of the frame
design contributed to the relatively straightforward aligning
of the thrusters with the centres of drag for increased
dynamic stability. The nature of the frame also allowed the
thrusters to be easily mounted in positions where they
would minimise potential magnetic interference with
onboard electronic devices.
Figure 5: Skeletal Frame view side of an AUV
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Figure 6: Skeletal Frame front view of an AUV
B. Fibre-reinforced plastics (FRP)
Once the skeletal frame of an AUV is done, the next
process is fibre process. Figure 7 (a) is the process of
skeletal frame made up of aluminium enclosed with fibre-
reinforced plastics. Figure 7 (b) and (c) is the same process
that is the skeletal frame enclosed with fibre-reinforced
plastics to make the desired design following the design
using the software.
Figure 7(a)
Figure 7(b)
Figure 7(c)
Figure 7: Process of skeletal frame with fibre
C. AUV dimension
Figure 8 shows the hardware of AUV that the finalized
result for design and development of an AUV. The
actuators are functioned as well as project expected. Motor
for propeller work well controlled by manual controller. It
just for rotate clockwise for AUV moving forward. The
next planning the motor will be rotate anticlockwise for
AUV moving backward. The servo motor in AUV
functioned well because the driver for servomotor will be
designed for future planning of the project. As informed,
the movement of the developed AUV controlled of manual
controller. The future plan of the development will be
applied autonomous controller so that the developed AUV
becoming more intelligent and moving itself.
V-FACTORS AFFECTING AUV PERFORMANCES
Several forces act on an underwater vehicle that requires
consideration for better performances. These include added
mass, environment and pressure. Pressure is another
significant factor for underwater vehicles that needs to be
taken into consideration in the design process.
Figure 8: Layout of component in AUV
Figure 9: The final hardware of AUV
A. Added Mass
Another phenomenon that affects underwater vehicles is
added mass. When a body moves underwater, the
immediate surrounding fluid is accelerated along with the
body. This affects the dynamics of the vehicle in such a way
that the force required to accelerate the water can be
modelled as an added mass. Added mass is a fairly
significant effect and is related to the mass and inertial
values of the vehicle.
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B. Environmental Forces
Environmental disturbances can affect the motion and
stability of a vehicle. This is particularly true for an
underwater vehicle where waves, currents and even wind
can perturb the vehicle. When the vehicle is submerged, the
effect of wind and waves can be largely ignored. The most
significant disturbances then for underwater vehicles are
currents. In a controlled environment such as a pool, the
effect of these environmental forces is minimal.
C. Pressure
As with air, underwater pressure is caused by the weight
of the medium, in this case water, acting upon a surface.
Pressure is usually measured as an absolute or ambient
pressure; absolute denoting the total pressure and ambient
being of a relativistic nature. At sea level, pressure due to
air is 14.7 psi or 1 atm. For every 10m of depth, pressure
increases by about 1atm and hence, the absolute pressure at
10m underwater is 2 atm. The increase in pressure as depth
increases is significant and underwater vehicles must be
structurally capable of withstanding a relatively large
amount of pressure if they are to survive.
V - CONCLUSION
The mechanical and electrical structures of the project
have been well discussed and shown in previous chapter.
After that, the research result and problem finding also have
been described. Therefore, based on the research made, a
brief project conclusion of the development process and the
design of the actual AUV are given.
Autonomous Underwater Vehicles (AUVs) are robotic
submarines. They are a part of the emerging field of
autonomous and unmanned vehicles and are primarily used
as low cost reconnaissance tools. AUVs are valued for both
their expand ability and replace ability; they can be
deployed in hazardous environments without risking human
divers.
Economically, the potential for cheap scalability makes
AUVs ideal for large scale and long term data collection
tasks. This research aims to design and develop an AUV as
a test bed platform for a variety of research in underwater
technologies especially involving small-scale and low-cost
underwater robots. The prototype that will be developed
will have a fixed mechanical system, having a modular
electronic system that allows development of various
controllers, recording devices and sensors module.
It also can be used for testing and learning conventional
and advanced control algorithms and techniques to other
underwater systems. With a limited budget a small
autonomous underwater vehicle has been developed. The
mechanical structure is produced. Future development and
improvement with show that this compared to other AUV
projects, smaller and cheaper concept will succeed.
ACKNOWLEDGEMENTS
We wish to express our gratitude to honorable University
(Universiti Teknikal Malaysia Melaka) especially to
higher management for give the financial as well as moral
support. And also would like to thank UNIC because their
tolerance for complete this project successfully.
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