2.1 Mechanical Design
The specific functions and mechanisms required for both robots are the two
important points in the mechanical design. For the MR1, it requires a lot of manoeuvring
and has to function as a collector with the throwing capability. Therefore, the MR1 has to
be designed to be strong and firm enough to withstand the throwing force while at the same
time can move at high speed to ensure that the Gerege is passed within one minute.
As for the MR2 robot, it also requires to manoeuvre along the path, as shown in
Figure 1, on leg mechanism. Therefore, the design for the MR2 focuses the development of
the four legs such that it can function and move simultaneously, that is able to move forward
and manoeuver through its required paths. The following sub-section will further explain
the design of both robots.
2.1.1 Messenger Robot 1 Mechanical Design
The team had conducted a meeting and decided to design a manual control robot for
this unit. First of all, a rectangular shape was selected as the base for this unit out of three
initial proposed shapes such as round and triangle. The selection was based on the wheels
positioning which consist of four Tran’s wheels. After a study was conducted, there was a
total of seven directions that the robot had to travel as illustrated in Table 1.
Table 1: Messenger Robot 1 Direction Study
No. Obstacles Direction of Movement
1 From starting area to Forest Area
2 Forest
and
3 Bridge
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4 Bridge to Gobi Urtuu
5 Gobi Urtuu to Throwing Zone
And
Therefore, to save time and increase the effectiveness of every motion, the team had
decided to use four units of Tran’s wheel for this robot. The frame selected was rectangular
with specification as given in the schematic in Figure 2.
450m
m
460mm 100mm
Figure 2: Plan View of the MR1 Base and type of transwheel
The second criteria required for the MR1 was the ability to pick up the Shagai on
the floor and load the Shagai to the Throwing Zone. Therefore, the team had come out with
three more concepts for the pick-up and the loader. Through various simulations, the team
finally decided the concept of using linear motor and a shovel due to its ability to precisely
locate and pick up the Shagai on the floor compared to the other two options which are more
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dependable on the operator control skill which could become a liability to the team. Figure
3 shows the Shagai pick-up and the loader.
Figure 3: Shagai pick-up and loader (shovel)
The third criteria were the Shagai thrower. The main thrower mechanism used
pneumatic piston of diameter dimension of 25 mm X 100 mm with six bars of pressure. In
order to shoot the Shagai in the area of about 2.2 m long, the robot needed an adjustment to
be raised to an angle of 45 degrees with an extension of 300 mm for the loader to achieve
approximately 2.2 m trajectory range. This was achieved by using two pneumatic pistons
(diameter dimension of 16 mm X 100 mm) that were fixed at the base. Two units of
extension rods also powered by pneumatic piston (size diameter 25 mm X 350 mm), were
used. For these pneumatic pistons, the design used two units of single solenoid valve 5-2
ways. For the shooter, the pneumatic controller used a Double solenoid valve 5-3 ways as
shown in Figure 4.
The final criteria for MR1 is the Gerege holder. For this, the team had decided to
use two servo motor design as the gripper and the passing arm.
2.1.2 Messenger Robot 2 Mechanical Design
Similar to the MR1, the MR2 had a rectangular base with four legs. After a study
was conducted, the overall legged robot was designed to have two simultaneous motions in
each movement for stability. The frame was designed to use the lightest material to make
sure 12 V power window (standard) could withstand the total load of the robot which was
approximately 10 kg.
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Figure 4: Angle raiser mechanism
During the development stage, the team faced challenges in determining the uniform
load on each motors. The simulations in CAD-CAE software shows that the movements
were smooth. However, during the testing after the assembly, the team faced a problem to
identify the load on each of the motor due to limited equipment on our site. Therefore, the
team had to perform a trial-and-error test in determining the load on the motor in order to
make sure the leg’s motion was appropriate. Trouble-shooting using appropriate
programming also took placed to solve the speed of motions and synchronizations problems.
Details of the MR2 mechanical design is shown in Figure 5.
2.2 Electronic Design
For electronics design, team had decided to use Arduino Mega 2560 system on both robots.
The details of specifications are in the following subsections.
2.2.1 Messenger Robot 1
SmartDrive Duo-60 2 units as driver.
Relay module 3 units as solenoid valve controller.
USB Host Shield 1 unit as Bluetooth communicator.
RC Servo Motor 2 unit as gripper and arm.
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Figure 5: The MR2 mechanical design
2.2.2 Messenger Robot 2
MDD 10A 2 units as driver.
Sensor capacitive four units as a counter.
2.3 Software Design
For the software design, KOGAS team provides an autonomous programme for the
MR1 as shown in the flow-chart in Figure 6.
(a)
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(b)
(c)
Figure 6(a)-(c): Flow-chart of the MR1 Programming.
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3.0 PRESENTATION OF DATA
This section presents the testing results which show the performance of both robotic
units prior to the competition. The testing for the MR1 include the speed test from the
starting point to Gobi Urtuu point and Shagai Throwing Range in meter. The MR2 mostly
involved the speed test in the Gobi Area. The summary of test result is given below.
3.1 Speed Test for MR1
Table 2: MR1 Speed Performance Test
NO. TEST BATTERY RESULT
(SECOND(S))
TEST 1 12.5 38
1
TEST 2 12.4 32
2
TEST 3 12.2 35
3
TEST 4 11.8 32
4
TEST 5 11.4 38
5
TEST 6 11.2 36
6
TEST 7 10.8 38
7
TEST 8 10.6 36
8
TEST 9 10.4 33
9
TEST 10 10.2 30
10
AVERAGE 35
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3.2 Shagai Throwing Range
Table 3: Shagai Throwing Range Performance Test
NO. TEST Pressure (bar) RESULT (Meter)
1 TEST 1 6 2.3
2 TEST 2 5.5 2.3
3 TEST 3 5.0 2.3
4 TEST 4 4.5 2.3
5 TEST 5 4.0 2.0
6 TEST 6 3.5 2.0
7 TEST 7 3.0 2.0
8 TEST 8 2.5 2.0
9 TEST 9 2.0 1.8
10 TEST 10 1.5 1.8
AVERAGE 2.08
3.3 Speed Test for MR2
Table 4: The MR2 Walking Speed Performance Test
NO. TEST BATTERY 1 BATTERY 2 RESULT
(SECOND(S))
1 TEST 1 12.4 12.5 45
2 TEST 2 12.2 12.4 45
3 TEST 3 12.0 12.2 45
4 TEST 4 11.5 11.8 45
5 TEST 5 11.0 11.4 45
6 TEST 6 10.8 11.2 45
7 TEST 7 10.4 10.8 45
8 TEST 8 10.2 10.6 45
9 TEST 9 9.7 10.4 47
10 TEST 10 9.4 10.2 47
AVERAGE 45
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4.0 CONCLUSIONS, LIMITATIONS AND RECOMMENDATIONS
In conclusion, it may be said that the design and the development of the two robots
meet all the objectives of this project. In additional, the testing results show that the
performance of the two robots met the required design specification. Subsequent testing of
motion speed and throwing were also designed in accordance with the specification of
ROBOCON 2019 Rules. Our project meet the criteria of joining the competition.
5.0 ACKNOWLEDGEMENTS
ميح رلا نمح رلا الله مسب
First, we would like to express our thanks and gratitude to the almighty and gracious
Allah ( ت.و. س ) for bestowing us with mercy, patience, knowledge, strength and blessing so
that we can finally complete our project.
We would like to extend our thanks and gratitude to all parties who were involved
directly or indirectly towards the completion of this project, especially to our Director of
ADTEC Kulim, and our colleagues for their help. Lastly, may this journey be a blessed one.
References
[1] https://ROBOCONmalaysia.com/about/.[online]. Available.
[2] http://abuROBOCON2019.mnb.mn/en/about/show/24. [Online]. Available.
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UMS from Universiti Malaysia Sabah
TEAM SUPERVISOR: Assoc. Prof. Ir. Dr. Muralindran Mariappan
TEAM ADVISORS: Dr. Khong Wei Leong
En. Irwan Baharudzaman
TEAM MEMBERS: Kek Jing Foh
Lim Kean Boon
Tan Zi Kai
Lee Kuan Lim
Soh Chia Seng
Lee Kin Wai
Stanley Ka Gong Sheng
Fong Seng Yau
Tiong Lin Rui
Chia Kai Yee
Christine Lo Yuh King
Rahmat Hidayat Bin Arifai
Mohd Nur Syafiq Bin Noor
Ong Tun Yau
ABSTRACT
ROBOCON Malaysia 2019 requires students to build two robots to complete tasks given.
Messenger Robot 1 (MR1), is a manual robot controlled by an operator using wireless PS2.
The MR1 is designed in such a way that it moves in holonomic motion which is commonly
implemented in traditional ROBOCON competition. The MR1 picks up a Shagai using
pneumatic-powered gripper and the gripper will then be flipped to the platform for shooting
purposes. The pneumatic cylinder is mounted at the top of the slider. The shooting
mechanism idea came from conceptualizing a catapult where an elastic band such as rubber
is used to shoot the Shagai once it is released. A power window motor is used to release or
tighten the rope that is attached to the rubber. A servo-controlled gripper is also used to pass
the Shagai to the Messenger Robot 2 (MR2). The MR2 is a fully automatic robot. It has to
have four legs or otherwise, four contact points to the ground. The robot is designed in such
a way that the joints are mounted to the power window motor as actuation. The legs will
then have continuous motion as the joints are rotating.
1.0 INTRODUCTION
ROBOCON is a robotic competition where a team of students is required to build
robots that can overcome challenges based on the competition theme. For this year, two
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robots are required to be built. One of them is a manual or semi-automatic robot while the
other is fully automated.
To simplify the situation, the MR1 has several tasks. It has to travel a distance to
pass the Gerege to the auto robot. Once it passed the Gerege to the auto robot, the MR1 can
pick up the Shagai while waiting for the MR2 to reach its destination, that is Mountain
Urtuu. After that, the MR1 can enter into the Throwing Zone to shoot the Shagai to the
Landing Zone. Once the MR2 receive the Gerege from the MR1, it has to travel in straight
line and also turns its direction following the path to reach Mountain Urtuu. Once it reaches
Mountain Urtuu, team members can physically turn its direction to reach the Uukhai Zone.
The final task for the MR2 is to lift up the Gerege after receiving it from the MR1.
2.0 DETAILED DESIGN
2.1 Mechanical Design
2.1.1 Mechanical Design for the MR1
The design of the MR1 can be separated into several stages. First, we have to
consider what types of movement we need to use, either omni-wheel, mecanum wheel or
two back wheels for forward motion. We have decided to use mecanum wheel because in
the Forest Zone the path is straight and also has left-right directions. It is easier for the
programmer to tune if the robot has slightly deviated from the desirable path. The Mecanum
wheel dimension is 100 mm and mounted with coupler to a DC motor. The base dimension
of the MR1 is 700 mm x 700 mm and built using aluminium. To grip the Shagai, we decided
to use the pneumatic cylinder mounted to a slider. Both ends of the slider are attached with
aluminium covered by a cushion in order to minimize the impact while gripping the Shagai.
This gripper is then mounted to a rod where the end of the rod is mounted to a power window
motor. The power window motor will then turn the gripper to the platform to place the
Shagai. The platform is inclined so that the shooting is in a projectile motion. The shooting
mechanism is controlled by another power window motor which is used to tighten or release
the ropes that are attached to the rubber. When the power window motor tightens the rubber,
two linear actuators will release its strokes to hold the rubber. The ropes will then be released
for the next shooting. The strokes will then be lowered down to release the rubber in order
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to shoot the Shagai. The servo-controlled gripper is mounted on one side of the base so that
it can pass the Gerege to the MR2 easily.
2.1.2 Mechanical Design for the MR2
The MR2 is a four-legged robot. The frame of the MR2 is rectangular as to imitate
the body shape of an animal. Initially, the MR2 is designed such that the servo motors are
used to actuate itself. However, we found out that the torque supplied is not sufficient
enough and there is little gap between the servo arm to the gear head, causing a very fragile
motion. We then decided to use the power window motor as it provides more torque. Long
screws are used to act as joints. The motion of the legged robot is then relied on the rotation
of these joints. The pedal is designed to have large contact surface area to avoid any slipping.
Rubber is used to provide better grip to the ground. This pedal is made flexible because we
want the legs to step on uneven ground, including to step on an inclined angle. Rubber is
used to tie the pedal to the legs so that the pedal could be twisted when it lands on the
ground.
2.2 Electronic Design
2.2.1 Electronic Design for the MR1
Table 1 explains the selection of components for the MR1.
Table 1: The MR1 Electronic design
No. Electronic devices Quantity Uses
1 DSPIC micro- 1 - Executes operations which are 7
controller motor drivers in 1 instruction
2 Motor driver 7 - 4 of the motor drivers are used to
control the direction and speed of the
brick robot
- 2 of the motor drivers are used to
control the direction and the speed of
the gripper
- 1 of the motor driver is used to tighten
and loosen the rubber
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3 IR sensor 1 - Detects the white strip on the motor of
the gripper in order to reduce the
impact of knocking
4 Relay module 1 - Control the circuit either it is normally
open (NO) or normally close (NC)
2.2.2 Electronic Design for the MR2
The sensor that we have chosen for the MR2 is IR sensor module. The function of
the IR sensor in this robot is to detect the rotation of the joint of the power window motor
in order for the programmer to easily adjusted the motion of the robot’s legs. Moreover, the
controller that is used in the MR2 is DSPIC30f4011 which uses Harvard architecture with
separate programme and data memory buses. This controller is ideal for motor controller
application due to its powerful and high performance micro-controller as well as high speed
core optimized to perform complex calculations quickly. The micro-controller also includes
a large 48 kB internal flash memory and a wide range of timers together with a number of
PWM modules for adjustable motor speed control of the robot.
Furthermore, the DSPIC30F4011 controller board also includes a large number of
general I/O pins that are very useful for the connection of sensors to adjust the motion of
the robot. This controller uses UART (Universal Asynchronous Receiver/Transmitter)
protocol in full duplex mode which means that the transmission and reception can occur
simultaneously. It enables an advanced communication between the two robots. Power
distribution board is used to supply the electricity for each motor driver circuit. Other than
that, there are four DC motor controllers to drive the power window motor to run the legged
robot. Figure 1 illustrates the electronic set up for the MR2.
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Figure 1: Electronic design for the MR2
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2.3 Software Design
2.3.1 Software Design for the MR1
Figure 2(a)-(f) show the flow-charts of the programming for the MR1.
(a)
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(b)
262
(c)
263
(d)
264
(e)
265
(f)
Figure 2(a)-(f): Software design for MR1
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2.3.3 Software Design for the MR2
Figures 3(a)-(c) show the flow-charts of the programming for the MR2.
(a)
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(b)
268
(c)
Figure 3(a)-(c): Software design for the MR2
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3.0 CONCLUSION
In a nutshell, two robots were designed and fabricated based on the tasks assigned.
Although the robots were not fully developed yet due to certain constraints such as lack of
workforce and financial support, we had tried our best to improve the performance of both
robots. ROBOCON Malaysia 2019 is unique and much more challenging as compared to
previous themes because it is the first to introduce quadruped robot into the world of
ROBOCON. We learnt a lot throughout this theme especially on wheeled robots. In the
future, we hope that we will be able to obtain sufficient financial support in order for us to
build better robots in terms of performance and technology.
4.0 ACKNOWLEDGEMENTS
We would like to thank Universiti Malaysia Sabah for supporting our team
throughout the preparation of the robots. Without the help from the university, it is difficult
to load our robots from Sabah to peninsular Malaysia during the competition. On the other
hand, we appreciate the help from the Student Affair Department, especially Madam Cik
Kamisa for the full support and commitment to allow UMS Robotics Club to represent UMS
for ROBOCON. We would also like to thank Dean of Faculty of Engineering, Prof. Ir. Dr.
Abdul Karim Mirasa for his support and encouraging us in terms of material acquisition and
also the permission to use laboratory equipment. Last but not the least, we would also like
to thank everyone who has directly or indirectly help us throughout the preparation of
ROBOCON Malaysia 2019.
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UTP PETROBOTS from Universiti Teknologi Petronas
TEAM SUPERVISOR: Ho Jia Wern
TEAM ADVISORS: Ang Kaizhe
Jason Tan Wei Qing
TEAM MEMBERS: Fathy Rashad
Joel Pang Wei Yu
Lim Shen Hua
ABSTRACT
This report deals with the development process of building two messenger robots for
ROBOCON 2019. The Asia-Pacific Robot Contest (ABU ROBOCON) is an Asian-
Oceanian College robot competition. It was founded in 2002 by Asia-Pacific Broadcasting
Union. In the competition, the robots compete to complete a task within a set period of time.
Great Urtuu is the main theme of this year ROBOCON. The target is to reach the Uukhai
Zone and raises the Gerege as fast as possible. Competing team members should be accurate,
fast and cooperative. A semi-auto robot (Messenger Robot 1) and a fully automatic robot
(Messenger Robot 2) will be used in the competition. Both of the messenger robots play an
important role in the competition. The design and mechanism of these two robots were based
on the Abu ROBOCON 2019 competition specifications and rules. The semi-auto robot will
able to compete with other team to complete the task in a shorter time.
1.0 INTRODUCTION
1.1 Back ground
A robot is a machine usually programmable by a computer, and capable of carrying
out a complex series of actions automatically. The word robot was coined by the Czech
writer Kapek in his play ‘Rassum’s Universal Robots’. Since then, countless devices have
been created and have been associated with the word ‘Robot’. The works of Issac Asimov
have laid the foundation of sociology pertaining to the use of robots instead of humans. And
the word ‘Robotics’ was also coined by him. In today’s world, work on robots, that resemble
and look almost human and others which do not resemble humans in any way, progresses
by leaps and bounds.
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In this era where organisations like Asia Pacific Broadcasting Union (ABU) are
organizing robot contests like ROBOCON, we have made an attempt to make semi-
automatic or fully automatic robotic systems which could complete a specific course and
tasks given. Today when technology is developing faster than a blink of an eye and the
competition is tougher to win whether at national or at international levels, we have to put
in tireless efforts to implement the technology in simpler and effective way to compete
against some of the best teams in the field of robotics in the country.
1.2 Problem Statement
The idea of semi-auto robot came from the last ROBOCON 2009 entitled Travel
Together for the Victory Drums and the fully automatic robot came from ROBOCON 2011
with the theme of Loy Krathong, Lighting Happiness with Friendship. Manual robot has
some weakness. For example, the user has to focus on operating the robot and sometimes
he or she must control two or more parts at the same time and these increases the possibility
of making mistakes and thus delay the movement of the robot. To construct a good semi-
auto or fully automatic robot, the robot must have a clear set of goals. Therefore, some of
the characteristics that should be presented in the robot are:
a) Stability: The weight of the robot must be suitable with its function. The size of the robot
also affects the weight of the robot. If the robot is too tall, the robot becomes less stable.
b) Automatic: The robot is programmed so that it functions automatically or can move by
itself.
c) Efficiency: The robots has good combination of motor/servo, base and other functions
that can perform fast with good precision.
1.3 Objectives
The project’s objectives and its descriptions are as the following:
a) Design two robots for ROBOCON 2019.
- Build the structure and other parts of one semi-auto and one fully automatic robot
which can function perfectly and can do the tasks given.
b) Test the performance of the robots.
- Test the function and the efficiency of the robots. Redesign and improve the
robots.
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c) Identify design of both robots that can be improved to automatic.
- Identify and improve the parts of robots to make them to perform more smoothly
2.0 DETAILED DESIGN
2.1 Messenger Robot 1
2.1.1 Mechanical Design
The Messesnger-Robot 1 (MR1) consists of two main parts; 1) Base and 2) Gripping
and Shooting mechanism.
2.1.1.1 Base
The base consists of three main components:
Body of the base
Motors used for the drives
Wheels used for the drives
The body of the base is made of a rigid and transparent perspex. This perspex enables
us to see clearly the structure beneath it. The perspex is durable while at the same time
providing a great support to the other components above it. The frame of the base is made
of aluminium because of its light weight and its ability to bear high stress. We have used a
square base frame. The whole frame is joined by welding work as it reduces the weight of
the frame and also do not produce any stress concentration on the frame which generally
occurs on the frame that is joined using bolts and nuts.
The motor used for the drive is very compact and has very high torque. Due to its
high torque, it can easily bear a load of 50 kg which is the maximum weight limit set in the
ROBOCON 2019. It also allows smooth drive of the bot along all turns and corners. The
basic information of the motor used are:
Weight: 609g
RPM: 248
Name of Company: Cytron (Sha Yang Ye)
Torque: 10 kgfcm
We have used three omni-wheels on the base of the robot. An omni-wheel, as shown
in Figure 1, has the holonomic drive property which means it can move freely. As a result,
a holonomic drive can shift from side-to-side or move diagonally without changing the
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direction of its wheels. Omni-wheels are also used to minimize drag. This is because they
are light, simple, and has the best performance when travelling diagonally. The Omni-
wheels are usually bumpy and has low torque for pushing but the rotation speed can be
adjusted wirelessly depending on the torque produced by the motors.
Figure 1: The omni-wheel
2.1.1.2 Gripping and Shooting Mechanism
Shooting mechanism consists of two main parts; 1) grip-and-throw part; and 2) air-
tank system. Grip-and-throw part is made of aluminium. This is because aluminium is a
light-weight material and malleable. The gripping part is covered with a layer of silicon to
increase the friction between the Shagai and the part. The grip-and-throw part motion
depends on a hydraulic system i.e. via the piston principle. Pressure is applied to the piston
to generate a force to grip-and-throw the Shagai. The air-tank system is also used to assist
the gripping and shooting mechanism system. Air-tank system consists of pneumatic part
and pumped bottles. The pneumatic part contains numerous tubing to transfer pressure to
the hydraulic system. Bottles are pumped before the competition to supply enough pressure.
We have used soft-drink-water bottles because of the lining of the bottles are thick enough
to withstand the pressure. The cap of each bottle is sealed with epoxy to avoid leakage of
air. Six bottles are pumped until pressure has reached six bars or above each.
2.1.1.3 Problems Faced
There were two main problems in the development of our robots. They were:
Dimension error
Insufficient of power
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The shooting mechanism which was placed above the MR1 bot had added to the total height
of the robot which did not met the specification set by the rules. The pressure transferred
from the air-tank system also had insufficient power to throw the Shagai into the Landing
Zone.
2.1.2 Electronic Design
2.1.2.1 Robot’s Drive
The robot’s drive is designed to be used as a multi-purpose drive.
Line following mode
Manual drive mode
The line-following mode of the drive is used when we need the bot to travel in the
main area and in accordance with the lines made on the game field from the starting zone to
the loading zone with ease.
The line-following mechanism on the MR1 bot is used to quickly get from the
starting zone to the loading zone of the game field (passing through the poles set). This is
done using the Cytron LSA08 sensor. It has two modes to be used:
Digital value mode
Analog value mode
Figure 2: LSA08 Sensor
We have used the digital value mode which can instantly follow the fixed value that
we have set at the starting zone. The digital value mode can make a quick response when
there is a turn at the pole and it enables the bot to move faster. Analog value mode was not
selected because this mode will keep the bot to always follow the line which will decrease
its speed as it keeps adjusting its position.
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2.1.2.2 Problems faced with the drive
We had faced numerous problems with the drive and most of them were due to
unevenness in the feed-back. Therefore, we had to refine the codes such that the unevenness
was eliminated. The problems we faced were:
Uneven drifting of the bot
Over velocity at the loading zone
2.1.2.3 How We Overcame Them
The uneven drifting of the bot was mainly due to the inertia caused by the bot when
making a turn. This was because the distribution of the components differs on every single
part on the base of the bot. Certain wheels will lack of force or overflow of force which
caused the drifting. After a few testing to observe the wheels and modifying the speed
(adjusting code) of the wheels causing the drift, the movement of the overall wheels are
balanced.
In order to shorten the time for the bot to reach the Landing Zone, faster speed is
needed to move the bot in a shorter time. This caused the bot to have difficulty to stop when
reaching the loading zone and may crash. Therefore, we re-programmed the speed of the
wheels such that when the bot have reached the final state, we will be able to slower its
speed and prevent it from crashing.
The manual drive mode is used so that the operator can change or manipulate the
bot’s position and orientation at a point where it is needed.
2.1.2.4 Controller Interface
We decided to use the ps2 controller to control the bot by changing different modes
based on different situations. Initially we planned to use the wireless controller as it is easier
to be connected and has high efficiency in data transmission. However, we considered that
the budget for buying a wireless controller was not worth it and the strength of the signal
depends on the location which indirectly causing much uncertainty. So, we had used ps2
controller which has a built-in Bluetooth module and more budget-friendly compared to a
ps4 controller. The Bluetooth module has stable data transmission and lower power-
consumption when compared to using wireless-based device.
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We have used a Bluetooth HC module on the Arduino as a master receiver on the
MR1 bot. After configuration, ps2 controller works as a slave Bluetooth device and keeps
sending data to the Arduino so the bot can be controlled within the calculated range using
ps2 controller. This gives us a better experience in controlling as long as Bluetooth module
can provide stable transmission of data without any delay.
2.2 Messenger Robot 2
Figure 3 shows the MR2 bot we built.
Figure 3: The Messenger Robot 2
2.2.1 Mechanical Design
The MR2 is a fully automated robot which moves on four legs. Each leg has three
joints driven by a servo. While walking, one of the leg will be in the air and other three will
stay on the ground for support. This motion is repeated with the other legs. The motion
resembles how a spider walk. The bottom part of the leg is designed to be bent so that it can
withstand the weight of the robot. Every part of the MR2 is printed out using PLA filament.
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PLA is polylactic acid, a biodegradable (under correct conditions) thermoplastic derived
from renewable resources such as corn starch or sugarcane. PLA filament is easy to use
and environmental friendly.
2.2.2 Electronic Design
The servo used for the joints is Annios 25 kg RC digital servo which has a large
torque that supports the movement of the fully automated robot. Other than that, four Citron
8-channels RC servo controller shields are used for each three of servos and an Uno Arduino
board is used to control the motion of the servos. The Arduino is powered by a 0.5 V battery
and the servos are powered using a 12 V LiPo battery.
2.2.3 Software Design
Figure 4: Flow-chart of the design
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START
A
SET CONSTANT FOR SERVO const float spot_turn_speed = 40;
CytronServoShield servo1; const float leg_move_speed = 100;
CytronServoShield servo2; const float body_move_speed = 80;
CytronServoShield servo3; const float stand_seat_speed = 40;
CytronServoShield servo4; const float gyrate_speed = 0.8;
const int ser vo_pin[4][3] = { {2, 3, 4}, {5, 6, const float bow_speed = 1;
7}, {8, 9, 10}, {11, 12, 13} }; volatile int rest_counter;
SET CONSTANT FOR SIZE OF ROBOT
const float KEEP = 255;
const float length_a = 85; const float pi = 3.1415926;
const float length_b = 245; volatile float site_cg[4][3];
const float length_c = 45;
const float robot_side_length = 70.84;
const float length_side = 210; const float robot_front_length = 77.92;
const float z_absolute = -250; const float robot_centre_to_pivot =
const int WALK = 0; sqrt(pow(robot_side_length / 2, 2) +
const int RELAX = 1; pow(robot_front_length / 2, 2));
const int SP RAWL = 2; const float move_angle = 15;
const bool FALSE = 0; const float temp_hyp = sqrt(pow(x_default -
x_offset, 2) + pow(y_start + y_step, 2)) +
const bool TRUE = 1; robot_centre_to_pivot;
volatile float site_now[4][3];
const float angle_1 = atan((y_start + y_step, 2) /
volatile float angle_expect[4][3]; (x_default - x_offset, 2));
volatile float site_expect[4][3]; const float move_x1 = temp_hyp * cos(angle_1
volatile bool capture = true; - move_angle);
float temp_speed[4][3]; const float move_y1 = temp_hyp * sin(angle_1 -
move_angle);
float move_speed;
float speed_multiple = 1; const float move_x2 = temp_hyp * cos(angle_1
+ move_angle);
int leg_position
const float move_y2 = temp_hyp * sin(angle_1
+ move_angle);
const float half_step = 10;
const float cg_shift = 14;
Figure 5: Flow-chart of the programme
3.0 PRESENTATION OF DATA
No simulation is done during the development process as the method we use is a
trial and error one.
279
4.0 CONCLUSION, RECOMMENDATIONS AND LIMITATIONS
As conclusions, both of the messenger robots are able to perform and complete the
tasks given. For the MR1, it is able to use the GPS to recognize and follow the white line
and for the MR2, it is able walk and get through the obstacles automatically after the Gerege
is received. All functionalities have been tested repeatedly to meet the contest requirements.
We find an number of limitations during the making of the robots. For the MR1, the
Shooting mechanism placed above the MR1 bot caused the robot dimension to exceed
height limitation. The pressure transferred by the throwing mechanism had insufficient
power to throw the Shagai into the Landing Zone. Uneven drifting of the robot and over
velocity also occurred during the trial. For the MR2, the centre of gravity is too high, making
it unstable. There is also connection problem between the battery and the printed circuit.
The battery power also drained up really fast which led to the robot to act weirdly when the
battery has low voltage.
As for recommendations, there are some solutions for every limitation. For the MR1,
a different power source should be used so that the power is high enough to throw the
Shagai. As for the MR2, the programme should be coded so that the body of the robot is
lower to make it more stable. A spare battery should also be prepared to replace the used
battery to avoid problem.
5.0 ACKNOWLEDGEMENTS
The team is grateful to the industry, Vitrox and Murata for sponsoring us. Other than
that, we would like to thank our parents for supporting us during these busy days and also
to our lectures for allowing us to focus on the preparations for this competition. Thank you
also to UTP for supporting us.
Reference
[1] https://www.robotshop.com/media/files/pdf2/crawling_quadruped_kit_v2.0_for_ardui
no-user_manual_.pdf
280
G-Bot from German - Malaysian Institute
TEAM SUPERVISOR: Sham Firdaus Bin Md Ali
TEAM ADVISORS: Khairulbadri Bin Ahmad
Afiq Farees Bin Jamil
Ahmad Hafiz Bin Mohd Hashim
TEAM MEMBERS: Joven Say Poh Liang
Jeffonnie Alvine Ak Nabau
Muhammad Ikhwan Aidil B Mohd Ruslan
Muhammad Hasbi B Maslan Farid
Ryan Dickson Anak David
Putera Danie Faiz B Mohd Hazri
Azhan B Azhar
ABSTRACT
ABU ROBOCON started in 1991 and was restricted to teams from Japan only. Nowadays,
ROBOCON is open to all Asia-Pacific counties. Each year, the competition has different
topics and it will be held in different counties across Asia. Generally, two or more robots
must be used to complete the tasks. One of the robots will be manually controlled while the
other one is autonomous. The robots usually weight more than 10 kg and span in one square
meter area. German-Malaysian Institute (GMI) has participated in the event for the year
2018. The robots are built with aluminium material and upon testing and analysis have
concluded the design required to complete the task within the given time.
1.0 INTRODUCTION
ROBOCON Malaysia 2019 is also organised yearly in the country to select the best
two teams to represent Malaysia in the Asia-Pacific competition. For this year’s game, the
theme is based on Mongolia’s traditional way of transporting goods across countries, called
ULAANBAATAR. The teams must now create two robots. The autonomous robot must have
four legs like a horse and move without any wheels. The manual robot on the other hand,
has no restrictions in terms of movement. Each match will be between a Red team and a
Blue team. The match will only last for a maximum of three minutes.
281
2.0 PROJECT DESCRIPTION
2.1 Manual Robot
GMI built the robot which runs on 4 DC motors, accompanied by omni wheels to
allow flexible movement. Omni wheels allow the user to manoeuvre the robot easily and
quickly around sharp turn and obstacles in the game field. Servo motor and stepper motor
are not used in the movement of this robot because accuracy is not needed. DC motors on
the other hand is cheaper, fast, easier to code and can easily be wired to the controller. The
team uses a PlayStation 2 wired controller to manually control the robot since the
competition requires a manual robot to assist the other robot. This controller is plugged into
a Cytron PS2 Shield which is directly stacked on top of the Arduino Mega. The team chooses
a wired controller rather than the wireless controller to prevent unwanted signal interference
and the response is much faster than the wireless controller.
400mm
500mm
400mm
Figure 1: Isometric view of the Manual Robot
282
2.2 Autonomous Robot
Figure 2 shows the isometric view of the autonomous robot. The team build the robot
based on the concept of the spider. The robot is controlled by 12 servo motors which allow
accurate angular control. Each leg is equipped with three servo motors. One of the servo
motors is mounted on the body of the robot for controlling the forward and reverse motion.
The other two motors control the motions on the y-axis (up and down motions). Servo motor
can constantly provide feed-back to the controller by a built in sensor, unlike the stepper
motor which does not. Due to this particular reason, servo motor has the best angular control
and adjusts itself if the angle is slightly off.
400mm
300mm
500mm
Figure 2: Isometric view of the Autonomous Robot
283
3.0 PROJECT COMPONENT DESCRIPTION
3.1 Manual Robot
The manual robot consists of four DC motors, controlled by the PS2 controller that
is connected to the Cytron PS2 Shield and directly stacked on top on the Arduino Mega. A
DC motor will control the movement of the mechanical hand. A servo motor is placed at the
edge of the mechanical hand to grip the Gerege.
Table 1: List of major component used in manual robot
ITEM QTY DESCRIPTION
3
1. DC Motor 5 Linear Motor with 15N/cm torque. Max
speed 250rpm
2. Servo Motor 1 Torque 15kg/cm
3. Arduino Mega 1 ATMega 2560 controller
4. PS2 Controller 1 Standard Sony PS2 Joystick
5. Cytron PS2 Shield 1 Interface between controller and joystick
6. Lipo ion Battery 2 11.1V 2500mah
3.2 Autonomous Robot
The autonomous robot consists of 12 servo motors and is locked in place by a series
of “U” joint brackets. The slide switch, resister, LED, stackable shield and Arduino Mega
are placed together which act at the brains of the robot. A magnetometer sends the angular
position of the robot to the Arduino.
Table 2: List of major component used in autonomous robot
ITEM QTY DESCRIPTION
1. Servo Motor 12 Each leg consist of 3 servo motor.
2. U Joint bracket 18 Mounting for servo motor
3. Arduino Mega 1 ATMega 2560 controller
4. Stackable Servo Shield 2 Maintain the power
5. Lipo ion Battery 2 11.1V 2500mah
6. Slide Switch 3 Input signal to Arduino Mega
7. LED 1 Indicator light
8. Emergency stop button 1 Safety device
9. Resister (1K ohm) 1 Lower the voltage for indication lamp
10. HMC5883l (3-axis Magnetometer) 1 Sensor change of robot position
284
4.0 PROJECT CIRCUIT DIAGRAM
The project implements two complete circuit for the manual robot and autonomous
robot. The manual robot circuit diagram is shown in Figure 3. The circuit consist of all the
components used as mentioned in the project component description. Finally, Figure 4
shows the circuitry for autonomous robot.
Figure 3: The Manual Robot circuit
285
Figure 4: The Autonomous Robot circuit
286
5.0 PROJECT CONCEPT ANALYSIS
5.1 Analysis of Selection of DC Motors and Servo Motors
Table 3 shows four types of motors. Each motor has its own description, torque,
weight, pros and cons.
Type of Item
Motor Description Torque (kgf.cm) Weight Advantage Disadvantage
Power Power window 30 600 g -Large torque -Unable to control exact
Window motor for proton -Low cost around RM45 position
Motor -Locking mechanism with -Must use
worm gear encoder
-Easily attach to robot -Large in size
body -Heavy 600g
Planetary DC 24 V 148RPM 20 980 g -Large torque -High cost around
Geared 18kgfcm 45mm -locking mechanism with RM220
Motor Planetary DC magnetic brake -Heavy 980g
Geared Motor -Not easily to attach to
robot body
-Large in size
Metal Gear JX Servo PDI- 25.3 62 g -Large torque
Digital Servo 6225MG-300 -locking mechanism with
Degree PDI- pinion gear
6225MG 25kg -Low cost around Rm65
Metal Gear Digital -Easily attach to robot
Servo For RC body
Airplane -light 62g
-Able to control exact
position
-small in size
Micro Linear L12-R Micro 150 56 g -locking mechanism using -High cost around
Servo Linear Servo ball screw RM350
100mm 210:1 6 V -Large torque -Short stroke around 3
-Easily attach to robot cm to 10 cm only
body
-light 56g
-small in size
Table 3: List of DC Motors and Servo Motors
287
5.2 Movement Analysis of Autonomous Robot
The movement of the autonomous robot is based on the concept of a spider. The
moving process requires the robot to move both the right leg first before proceeding to the
right. The process is continuous for all terrains.
Figure 5: Movement of Autonomous Robot
5.3 Analysis of Robot Traveling Time
Travel time is calculated based on the speed of the servo motor. The recorded time
is the time taken for the motor to move 45 degrees. The time is then multiplied by four to
represent four legs.
X
45°
Figure 6: Robot traveling angle
288
1 Leg travelling time =0.25sec
1 step requires 4 leg movements = 1 sec
1 step = x cm
Sin 45°=
10
x = 8.5cm
1 step movement will result in range duration of 8.5cm
Total travelling distance of the field 800cm =requires y step
800
= y
8.5
y = 94 steps
94 step x 1 second = 94 second = 1 minute 56 second (The total time required to complete
the autonomous walking).
Figure 7: Game Field Top View
289
6.0 PROJECT FLOW AND SEQUENCE
The concept of the whole game is to have the manual robot holding the Gerege and
move through the obstacles (Forest, Bridge and crossing line). The manual robot reaches at
the starting point of autonomous robot and passes the Gerege. The autonomous robot
receives the Gerege and moves through the obstacles (Sand Dune and Tussock). Then, the
autonomous robot stops at the base of the incline plan and wait for manual robot to score 50
points before moving up the incline plan. Once the autonomous robot reaches the top of the
incline plan, it raises the Gerege and the game ends.
Figure 8: Concept of Contest
( M1 = Manual Robot / M2 = Autonomous Robot )
290
7.0 CONCLUSION
The team had invested all the knowledge, skills and time into this project. Each
member played their part in terms of providing mechanical, electrical, programming,
crafting skills and creative thinking into the creation of the two robots. The team have tested
the robots countless of times using prototype to make sure that all the flaws had been
corrected.
The robot requires aluminium material to be fabricated and constructed.
Furthermore, most electronics components used are recycled components to reduce the
amount of cost. The most expensive parts are the servo motor as high torque servo motor
is required. Other than that, each team member get to share the experience, skills and
knowledge with other team members.
The team learns more in this real project than in class because, building a robot
requires different perceptions, knowledge and skills which are brought together to complete
the project. The team can now look at things in a broader view because we know where to
apply this knowledge and show our understanding on the particular matter.
References
[1] Aswinth Raj, 2018, Digital Compass Using Arduino and HMC5883L Magnetometer,
CircuitDigest, November.
[2] Ober, 2013, Remote control with shield-ps2 + g15 as wheel, Tutorials by Cytron, October.
[3] BKIT CLB, 2013, Robot Spider BKIT4U 2013 (4leg test version), Youtube, June.
[4] ModMyPi LTD, 2013, What’s the difference between DC ,servo and stepper motor ?, ModMyPi
LTD, August.
291
IUKL from Infrastructure University Kuala Lumpur
TEAM SUPERVISOR: Budiman Azzali Basir
TEAM MEMBERS: Abdalla Imaldeldin Abdelrahim
Yeye Coulibaly Mahamadou
Lee Zheng Joo
Ayman Taher Alqurashi
S. Kanageswaran
ABSTRACT
This report addresses the work that has been undertaken in the design and development of
nine degrees of freedom (DOF) Dual Arms Omni-Directional Mobile Robot Manipulators
and autonomous quadruped robot as a part of the requirement in ROBOCON Malaysia 2019.
The team integrated a dual-arms robot with an omni-directional mobile robot to design a
nine DOF dual-arms omni-directional mobile robot. This allowed a flexible manoeuvring
for the mobile robot while the nine DOF dual-arm robot manipulators provide flexibility for
task handling. This semi-auto robot is capable to manoeuver around the set-up pole, delivers
the Gerege to the autonomous robot and also capable of lifting and throwing the Shagai into
the designated area. The autonomous quadruped robot is designed to mimic a movement of
a digitigrades such as a tiger, in a manner of moving the two legs on one side of the body
before moving the legs on the other side.
1.0 INTRODUCTION
This report documented the work that has been carried out by the team as a part of
the requirement in ROBOCON Malaysia 2019. This writing is organized as follows: Section
2 presents an overview of nine DOF Dual Arms Omni-Directional Mobile Robot
Manipulators design methodology and concept. Section 3 presents an overview of the
Autonomous Quadruped Robot design methodology and concept, and finally Section 4
presents conclusion and recommendation.
2.0 DESIGN OF A NINE DOF DUAL-ARMS OMNI-DIRECTIONAL
MOBILE ROBOT MANIPULATORS
Rapid developments in intelligent manufacturing have motivated the development
of mobile robot technology in recent years [1]. Intelligent factories have been increasingly
292
demanding autonomous mobile robots to fulfil various movement tasks [2,3]. Due to
complicated working environment, mobile robots need to be flexible, adaptive, and safe
[4,5]. There are many kinds of omni-directional mobile robots that have been developed and
produced [6]. Two common types of wheels that can realize the omni-directional movement
are the steerable wheel and the omni-directional wheel. Both of them have been used for
mature products, including Adept Seekur and KUKA omniRob robots.
Dual-arms robot manipulators are more capable of implementing complex tasks as
compared to a single arm manipulator robot. The advantages and benefits of dual arm robots
over a single arm manipulator system are multitasking, cost saving and space saving. This
technical report addresses the design of a nine DOF dual arms mobile robot manipulators.
There are many kinds of omni-directional mobile robots that have been developed and
produced [2]. Thus the team integrated the dual-arms robot with an omni-directional mobile
robot to design a nine DOF dual-arms omni-directional mobile robot.
The development for this project can be divided into two major stages; the
mechanical design for omni-driectional mobile robot and the dual-arm robot manipulator
design.
2.1 Omni-Directional Mobile Robot
This project utilized the mecanum wheel design pioneered in 1973 by Mecanum
AB’s Bengt Ilon. Mecanum wheel is based on the principle of a central wheel with a number
of rollers placed at an angle around the periphery of the wheel. The angled peripheral roller
translates a portion of the force in the rotational direction of the wheel to force normal to
the wheel directional. Depending on each individual wheel direction and speed, the resulting
combination of all these forces produces a total force vector in any desired direction. This
allows the platform to move freely in the direction of the resulting force vector without
changing the direction of the wheel. Figure 1 shows a traditional mecanum wheel designed
by Ilon with the peripheral roller set up at 45 degrees slope held in place from the outside.
293
Figure 1: Mecanum wheel based on Ilon’s concept.
Four of mecanum wheels are able to provide omni-directional movement for a
vehicle without needing a conventional steering system. Slipping is a common problem in
the mecanum wheel as it has only one roller with a single point of ground contact at any one
time. Due to the dynamics of the mecanum wheel, it can create force vectors in both the x
and y-directions while only being driven in the y-direction. Positioning four mecanum
wheels, one at each corner of the chassis (two mirrored pairs), allows net forces to be formed
in the x, y and rotational directions. Refering to Figure 2, we can see that the difficulty with
this strategy is that there are four variables to control the three DOF. In this case, the system
is said to be over determined and it may cause conflicts in the actuation. As a result of the
constraints associated with the mecanum wheel, some forms of controller is required to
produce a satisfactory motion.
Figure 2: Force vectors created by Mecanum wheel.
The omni-directional mobile robot was designed using a set of 100 mm mecanum
wheels which consist of nine rollers. Each roller’s diameter is 20 mm at the center and 16
mm at each end. All rollers are made by engineering plastic call delrin. All the mecanum
wheels are independently powered using four units of precision gear DC motor and the
wheel motor assemblies were mounted directly to the robot chassis. The used platform is a
square shaped that is attached with a wheel set up at +45º roller and a wheel set up at -45º
roller on each side. The omni-directional capabilities of the platform depend on each wheel’s
surface contact and some of the mecanum wheel mobile robots are equipped with
294
suspension system. For simplicity, our mecanum wheel and motor assembly are mounted
directly on the platform chassis that is made from 20x20 aluminium extrusion frame and 5
mm acrylic plate. The size of mobile robot is approximately 500 cm in width and 500 cm in
length. Figure 3 shows the design structure of the mobile robot.
The specifications developed for the necessary driver board are:
a) The circuit should be compatible with a single logic-level PWM input signal for speed
control of each wheel and a single logic-level input line for the direction of motor rotation
for each wheel.
b) The circuit should be able to operate with a high PWM carrier frequency from the micro-
controller (20 MHz) to provide inaudible operation.
c) The circuit would require four independent H-Bridge drivers for bi-directional motion.
The DC motors used in this platform was built-in 40:1 gear reduction and speed at
405 RPM at 12 VDC. The optical encoders provided velocity information on each wheel to
the micro-controller. A four-channel-high-power H-bridge driver board was interfaced to an
Arduino Mega controller. The overview system hardware architecture is shown in Figure
4.
Figure 3: Design structure of mecanum wheel mobile robot.
The following list in Table 1, shows the basic motion of mecanum wheel mobile
robot with their corresponding wheel direction. By varying the individual speed of the motor
wheel, we can achieve driving direction along any vector in X-Y axis. The actuation
required for these movements can be seen in Figure 5.
295
Figure 4: System hardware architecture.
Table 1: Motor control for basic motion.
296
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