threshold, then proceed with another climb up motion. The same process occurs during the
climb-down motion. The turning point that we use is 330 for climb-up and 280 for climb-
down.
4.0 CONCLUSION
There are a lot of improvement that can be made. For example, we can use external
sensors technology that allows the MR1 to have feed-back on its current location, and based
on that information we can allow the MR1 to carry out all the necessary tasks autonomously.
For the MR2, with improved mechanical design and the usage of lighter material, it will be
able to walk faster and more efficiently. The limitation of the MR1 is the weight distribution
because the throwing mechanism in front of the robot has caused the center of gravity of the
robot to shift towards the front. Another limitation is the vibration coming from the
movement due to the lack of suspension system. The limitation of the MR2 is due to the
expensive price of the motor.
References
[1] What is Projectile? n.d., Retrieved from the Physics Classroom:
https://www.physicsclassroom.com/class/vectors/Lesson-2/What-is-a-Projectile
[2] Equilibrium and Statics. n.d., Retrieved from the Physics Classroom:
https://www.physicsclassroom.com/class/vectors/Lesson-3/Equilibrium-and-Statics
[3] Elijah, J., 2016, How to Program a Quadruped Robot with Arduino. Retrieved from
Make:: https://makezine.com/2016/11/22/robot-quadruped-arduino-program/
[4] Mordvintsev, A., & K., A. 2013, OpenCV-Python Tutorials. Retrieved from OpenCV:
https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_tutorials.html
147
Robust UPNM from Universiti Pertahanan Nasional
Malaysia
TEAM SUPERVISOR: Dr. Syed Mohd Fairuz Syed Mohd Dardin
TEAM ADVISORS: Zuhairi Bin Abdul Rashid
Dr. Noor Hafizah Binti Amer
TEAM MEMBERS: Akram Bin Abdul Azid
En. Muhammad Hakirin Bin Roslan
En. Muhammad Luqman Hakim Bin Abd Rahman
En. Mohd Sabirin Bin Rahmat
Dr. Ahmad Shukri Bin Abu Hasim
Dr. Asnor Mazuan Bin Ishak
ABSTRACT
This report presents the design and development of robots submitted for the competition of
ROBOCON Malaysia 2019. The team consists of undergraduate students from National
Defence University of Malaysia. The work here consists of two robots, namely the
Messenger Robot 1 (MR1) with manual configuration and Messenger Robot 2 (MR2) with
automatic configuration. The main purpose of this report is to ensure that the work can be
presented in a clear manner.
1.0 INTRODUCTION
The importance of having a reliable messaging system is being demonstrated and
practised in this year’s ROBOCON competition. The mission is to deliver information faster
by using a relay messenger system, the Urtuu system. It was first invented by the nomadic
Mongolians. The UPNM Robust team comprises a group of students studying at National
Defence University of Malaysia in the field of Engineering and Computer Science. The goal
of our team is to develop an efficient system consisting of manual and automatic robots to
compete at the annual competition that is held in UNITEN. This is the group’s second
attempt in ROBOCON Malaysia, thus the target has been to rectify any past flaws and
imperfection in getting the essential framework of mechanical, electronic and programming
firmly incorporated before progressing towards further complexities.
2.0 DETAILED DESIGN
2.1 Mechanical Design
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The mechanical division of the team focuses on the design, prototyping and manufacturing
of the thrower, robotic arm and supporting truss for both robots.
2.1.1 The Robots
Slider
Thrower
Gripper
Sprocket
Chain
(a) (b)
Figure 8: Final design of the MR1 and the MR2 (a) the MR1 (b) the MR2
Figure 8(a) and (b) shows the final design of the MR1 and the MR2 robots
respectively. The square base for both robots are made up of plywood which house the
supporting frame, electronic components, batteries and the motors. The mounting points of
electronic components are located in such a way that the centre of gravity of the robot is
coincident with the robot’s geometrical centre and close to the ground, to avoid toppling at
any edge during motion. The overall dimension for the MR1 is 65 cm x 50 cm x 70 cm size
while it is 60 cm x 34 cm x 75 cm for the MR2. This is within the allowable dimension of
150 cm x 150 cm x 150 cm for the MR1 and 80 cm x 100 cm x 80 cm for the MR2 as in the
rule-book.
2.1.2 Movement Mechanism for the MR1
The movement mechanism of the manual robot uses a 15 cm mecanum wheel as
shown in Figure 9 which can move the robot in any direction. It consists of a hub with rollers
oriented at 45° about the axis of rotation. Mecanum wheel is perfect for tight spaces, since
it enables conventional forward and backward movements as well as side-to-side and even
rotations. The manual robot also uses a 24 V DC motor with a dimension of 80 mm x 80
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mm x 151 mm including the shaft to provide rotational motion to the wheel shaft, which
will move the robot.
Figure 9: Mecanum wheel
2.1.3 Walking Mechanism for the MR2
The MR2 is a fully automatic robot which moves on four legs. Both left and right
legs of the robot are connected to a motor. Configuration and assembly of each leg can be
seen in Figure 8 (b). Both legs on each side (left/right) are controlled by the same motor and
connected through a sprocket and chain mechanism. The left and right legs are connected
by a shaft that is fixed on the robot’s body with a pillow bearing to support and maintain the
position of the legs. From preliminary study, the step sequence that is chosen for the MR2
is 4-2-3-1 which is shown in Figure 10. This is because a support triangle is formed during
the movement of the robot, and therefore, less energy is required [1]. This walking
mechanism is used because it gives wider step and more stable walking movement. This
mechanism has seven linkages and seven joints on each leg, where each part is made of
several aluminium plates which are easily to fabricate, light and cheap.
Figure 10: Sequence of 4-2-3-1 walking mechanism
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2.1.4 Throwing Mechanism for the MR1
The throwing mechanism for the MR1 consists of a gripper, a slider, and a thrower,
each attached to a pneumatic system for actuation as shown in Figure 8 (a). The Shagai
throwing sequence starts with holding, lifting, and putting the Shagai into the slider which
is carried out by the programmed gripper mechanism. The gripper consists of cables, spring
and a pneumatic system. The function of the cable is to connect the gripper with the
pneumatic components, while the spring is used to limit the opening and closing of the
gripper. The slider consists of a pillow bearing and a pneumatic system within the
mechanism to turn the robotic arm and put the Shagai on the slider. The pneumatic system
for gripper has dimensions of 50 mm stroke and 20 mm bore size and is a mechanism that
is used to push the Shagai. After the slider receives the Shagai, it will extend its length
forward before the thrower starts throwing the Shagai into Landing Zone. It uses two
pneumatic systems to push the slider forward and push the Shagai into landing area, each
with dimensions of 200 mm and 20 mm bore size. All pneumatic systems used are operated
with pneumatic cylinder with maximum pressure of five bars and connected to solenoid
valve with 1-7 bars operating pressure range, as well as a set of soda bottles for the pressure
tank.
2.1.5 Lifting Mechanism for the MR2
Figure 11: The full assembly of lifting mechanism
The function of the MR2 is to receive the Gerege from the MR1 and lift it up to 1000
mm after reaching the Uukhai Zone. So, to accomplish the task, a pneumatic cylinder is
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fixed vertically on the base of the body with the dimension of 20 mm bore size and 200 mm
stroke. A pressure tank made of one soda bottle is connected to a solenoid valve with 1-7
bars operating pressure range and linked to the pneumatic cylinder. The pressure is set at
one bar and this has been proven to give the best performance from the trial-and-error tests.
Then, two grippers are arranged vertically parallel to make sure that the gripper grips the
Gerege properly. Also, a bowl-shaped metal is fixed under the gripper mechanism in order
to provide further support. This system will be fixed at the back of the MR2 to reduce the
movement of the MR2 while lifting the Gerege. For the detection system, two ultrasonic
sensors are used. One of the sensors is fixed on the pneumatic cylinder and another is fixed
on the grippers. The full assembly of lifting mechanism is shown in Figure 11.
2.2 Electronic Design
The electronic system for both robots acts as the conductor in translating the
mechanism to the desired movement based on the required task and operations. In both
robots, Arduino Mega micro-controller is used as the motherboard and main processor of
the system. The electronics and batteries are housed in a box with cables penetrating out to
the sensors, pneumatic and motors. The motors are mounted on optimized positions within
the frame for ease of robot’s movement.
2.2.1 Arduino Microcontroller
Figure 12: Arduino Mega
Arduino Mega is a micro-controller that uses ATmega2560 microchip. It has 54
digital input/output pins in which 14 pins can be used as digital (PWM) outputs, 16 pins for
analog inputs and four pins for UARTs (hardware serial ports) with a 16 MHz crystal
oscillator, USB connection capability, an ICSP header, and a reset button. The capability of
the Arduino Mega is considered sufficient for such operation in both manual and auto robots.
Furthermore, this will ease the implementation phase.
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2.2.2 Power Source
Both robots uses the same type of power source which is Lithium Polymer (LiPo)
battery. LiPo battery is a rechargeable battery with XT90 connector plug. There are two
different batteries used, which are 22.2 V 5000 mAH 6S 40 C LiPo Rechargeable Battery
and G-Max Power 2500 MAH 45 C 14.8 V 4S1P LiPo Battery, as shown in Figure 13 (a)
and (b), respectively. For the 6S LiPo battery, the minimum power capacity it can hold is
6000 mAh and can generate output voltage of 22.2 V. The dimension of the battery is 170
(L) mm x 50 (W) mm x 57 (H) mm. The big capacity is required for such application which
requires 24 V to operate.
(a) (b)
Figure 13: (a) 22.2 V 5000 mAH 6S 40 C LiPo Rechargeable Battery
(b) G-Max Power 2500 MAH 45 C 14.8 V 4S1P LiPo Battery
For the G-Max LiPo battery, it can hold a capacity of 2500 mAh and can generate
output voltage of 14.8 V with the dimension of the battery 110 (L) mm x 34 (W) mm x 33
(H) mm. This battery is mainly used to give power supply to Arduino Mega and other
components.
2.2.3 DC Motor for Robot’s Mechanism
The DC motor attached on both robots is 24 V DC motor with 300 RPM rated speed
as shown in Figure 14 (a). The DC motor is used to rotate the mecanum wheels on the
manual robot and to move the automatic robot’s legs. To minimize the number of driver
used, two DC motors are connected to a two-channel motor driver, which results in two
drivers are used for the mecanum wheels and the other pair is used for moving the legs. The
aim of using this type of DC motor is to achieve the high rated speed and torque which
produce more efficient and smoother robot motions.
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(a) (b)
Figure 14: (a) 24V DC Motor (b) PlayStation 2 controller
2.2.4 Controller for the MR1 (PlayStation 2 Controller)
A PlayStation 2 (PS2) controller, as shown in Figure 14 (b), is used as the primary
user-input-interface for the MR1. The main advantage of using the PS2 controller is that
the 15 buttons and two analog joysticks which can be programmed for different tasks.
2.2.5 Sensors and Actuators
(a) (b) (c)
Figure 15: Sensors and actuators used on the robots (a) Ultrasonic sensor,
(b) Solenoid valve, and (c) Linear actuator
Figure 15 (a) shows the ultrasonic sensor used in this project which uses 5 V (DC)
supply voltage and 15 mA current. It has 40 Hz modulation frequency and an output of 0-5
V (output high when obstacle detected in range). The range of distance it can cover is from
2 cm to 400 cm which has an accuracy of ± 0.3 cm. The sensor is attached to the robot to
detect the Gerege at a specific distance and give signal to the Gerege gripper to function.
Figure 15 (b) shows the solenoid valve used to regulate pressure input on each
pneumatic system for the robots. It has operating pressure range of 0.1 to 0.7 MPa and 12
V operating voltage requirement for operation. The Arduino will supply power through the
use of four-way relay module as a switch due to a restriction of 5 V supply voltage for the
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Arduino. The basic function of relay is to allow a low power control voltage operate a high
power switch, as the solenoid required 12 V to operate.
A linear actuator is used in the throwing mechanism of the Shagai in the MR1 as
shown in Figure 15 (c). This device requires 12 V to operate with 1000 N load capacity. The
full stroke of the linear actuator is 500 mm. The main advantage of using this device is that
it has high torque supply which is suitable for the weight of the gripper.
2.3 Software Design
The processes of the MR1 are shown in the flow-chart (see Figure 23). As far as the
MR2 is concerned, the input signals are obtained only from the PS2 controller. During the
initialization process right after the MR1 start-up, all the variables related to connect the
PS2 controller with the MR1 are being initialized.
Figure 16: Flow-chart process of the MR1
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Figure 17: The specific function assigned to the PS2 controller’s button
Referring to Figure 17, different buttons are assigned to its specific function to
achieve the objective of the MR1. The function of button A on the PS2 controller is for the
movement of mecanum tyres. Button B is to close the gripper in order to grip the Shagai.
Button C is to open the gripper. Button D is to flip the arm of the gripper. Button E is to
extend the slider. Button H is to return the slider to its initial state. Button F is to extract the
pneumatic cylinder and push the Shagai to the throwing area. Lastly, button G is to retract
pneumatic cylinder to its initial state.
Meanwhile, the processes of the MR2 are illustrated in Figure 18. As far as the MR2
is concerned, the input signal comes from the ultrasonic sensors and switches. There are two
ultrasonic sensors and two switches used. One ultrasonic sensor is fixed between the
grippers and another one is placed on the body of the MR2. Conditions of ultrasonic sensors
are based on the states of each switch. Initially, when the MR2 starts, both switches are set
in ‘LOW’ state which will activate the gripper’s ultrasonic sensor. If the sensor detects an
object (Gerege), grippers will start closing after two seconds delay and the MR2 will start
to move forward. If there is no object, the grippers will stay open. Upon successfully
gripping the Gerege, the MR2 will continue to walk through obstacles. After successfully
manoeuvring the obstacles, switch 1 will be set as ‘HIGH’ and switch 2 will remain as
‘LOW’ in order to stop and wait for the MR1 to throw the Shagai into the Landing Zone.
During this time, both ultrasonic sensors are deactivated. If the MR2 is not successful in
passing through the obstacles, both switches will be set as ‘LOW’ and the sequence will
restart from the beginning. After the MR1 has thrown the Shagai, both switches will be set
as ‘HIGH’ to activate the ultrasonic sensor on the robot’s body which will receive a signal
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to move forward for five seconds and lift up the Gerege. If there is no signal detected, the
MR2 will stay static until further signal is received.
Figure 18: Flow-chart process of the MR2
3.0 CONCLUSIONS, LIMITATIONS AND RECOMMENDATIONS
Two robots have been successfully built and developed to fulfil this year’s
participation in ROBOCON 2019. However, these robots have few limitations. Firstly, the
moving algorithm could be improved for a better autonomous motion. In the Shagai lifting
mechanism, a suitable motor can be used to improve the time taken to lift the Shagai. Other
than that, the two robots have performed within expectation.
4.0 ACKNOWLEDGMENTS
The team would like to thank the National Defence University of Malaysia for
continuous support towards the success of this project.
The team also credits the direct involvement of the affiliated team members and
supervisors as listed below:
Amirul Ariffin Bin Ahmad Jaya Muhammad Syimir Bin Mohd Azaman
Tee Kai Wen Norfarahana Adibah Binti Raffie
Hamirul Hafizal Bin Mohamad Muhammad Muaz Bin Shamsuddin
Kamaruddin Muhammad Nur Shafiq B. Shamsul
Nur Shafa' Binti Darmawan Iskandar
Nur Ain Shahira Binti Mohd Alias Azneen Awalliah Binti Mohd Amir
Nurnadia Nadira Binti Din Syam
Hemavathy A/P Palaniappan Normaizeerah Binti Mohd Noor
Sarah Husna Binti Muhamad Nazri Nadhirah Binti Hamdan
Siti Suriani Binti Jemssaini Nur Syairah Izzati Binti Ahmad Suhaidi
Nur Hafizah Bt Mohd Norhan Dr. Ahmad Shukri Bin Abu Hasim
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En. Akram Bin Abdul Azid
Dr. Asnor Mazuan Bin Ishak
En. Muhammad Hakirin Bin Roslan
Dr. Noor Hafizah Binti Amer
En. Muhammad Luqman Hakim Bin Abd
Rahman
En. Mohd Sabirin Bin Rahmat
Reference
[1] Huang, Y., Luo, Q., & Jia, Y., 2018, Study on walk step gait of quadruped robot based on
the support polygon. Journal of Physics: Conference Series, 1074, 012011.
doi:10.1088/1742-6596/1074/1/012011.
158
TARUCbotics V2 from Tunku Abdul Rahman University
College
TEAM SUPERVISOR: Dr Lum Kin Yun
Mr Tan Yong Li
TEAM ADVISORS: Dr Lum Kin Yun
Mr Tan Yong Li
TEAM MEMBERS: Fong Hao Nan (Team Leader)
Louis Lew Zun Kang
Yee Mun Jun
Kok Siong Yuen
Ooi Yao Sheng
Choong Qian Kai
ABSTRACT
In this report, both mechanical and electrical aspects of the MR1 and the MR2 are discussed
and investigated. The introduction discusses the back-ground of the game rule and the
reason for our the MR1 and the MR2 designs. In detailed design section, the mechanical
and electronics as well as software designs are given due explanation and Figures for
readers’ understandings and clarifications. Both flow-chart for process and programme
codes are listed in this section. Then, in the next section, results and data of stimulation and
testing are presented and tabulated for analysis purposes. The conclusion outlines the
strength and weakness of the project and propose suggestion for future actions.
1.0 INTRODUCTION
This is a report based on the ABU ROBOCON 2019 Ulaanbataar contest, where
each team is required to prepare two messenger robots which are the Messenger Robot 1
(MR1) and the Messenger Robot 2 (MR2). The MR1 is a wheeled mobile robot must cross
the Forest and bridge and then pass the Gerege to the MR2, whose design must be four-
legged robot and it must “crawl” or move automatically. Hence it is a sprawling robot in our
case. After receiving the Gerege from the MR1, the MR2 needs to cross Gobi Area, Sand
Dune, Tussock and stop before Mountain Urtuu. After that, the MR1 is required to move the
Shagai to the Throwing Zone and throw it to the Landing Zone, where obtaining different
orientations of the Shagai produce accorded results.
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Figure 1: Sprawling robot [1]
Once the 50 mark is obtained the MR2 will be allowed to climb up the hill and complete the
game. Sprawling robot is chosen as it has high stability by locating its centre of gravity at
low position, has a wider supporting leg polygon and it can easily pass through a place which
has limiting height.
Most of the four leg robot has two different types which include the sprawling robot
and mammal robot.
Table 1: Mammal types vs Spawling robot [2]
Mammal type Sprawling robot
Mammal-type quadruped robot can walk Sprawling robot has high stability, because
faster than a sprawling-type quadruped the robot can locate its centre of gravity at
robot by utilizing two actuators which are low position and have a wider supporting leg
hip and knee in each leg polygon.
2.0 DETAILED DESIGN
Figure 2s shows the motions that the MR1 and the MR2 need to perform during the
competition. To achieve this requires mechanical, electronic and software designs. In our
design for the MR1, there are four major parts which include movement of the MR1, the
passing Gerege, the lifting up the Shagai and the launching of the Shagai.
For the MR2, we have changed the design from spider robot to Klann linkage. We
change the whole the MR2 design because the motor used for spider robot breaks down.
Due to time constraint, plan B, the Klann linkage design, will replace the original plan.
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Figure 2: Sequence for the MR1 and the MR2 movement
2.1 Mechanical Design of MR1
The movement of the motor is very simple. The MR1 was controlled by user
manually.
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Figure 3: Designation for movement of the MR1
Figure 4: Passing the Gerege from the MR1 to the MR2
162
Figure 5: The Shagai lifting mechanism
Figure 6: The Shagai launching mechanism
163
2.2 Mechanical Design of the MR2
The original design for the MR2 is sprawling robot. Unfortunately, the motor of the
MR2 was damaged. Hence it was changed to due to limited budget. The original design was
replaced to klann lingkage.
Figure 7: The MR2 design for crawling in Gobi Area (Sand Dune, Tussock, Mountain
Urtuu and Mountain area)
2.3 Electronic Design
Figure 8: Arduino Due
Figure 9: DC-DC Adjustable Step-Down Voltage Regulator Module with 1.5-35 V DC
Output and 2 A
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Figure 10: USB Host Shield
Figure 11: 8 Way Channel 10 A 5 V Relay Module opto isolator
Figure 12: Smart Drive Duo-30
Figure 13: 12 V 405 RPM 6.5 kgfcm Planetary DC Geared Motor with Encoder
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Figure 14: Power Window Motor with coupling
Figure 15: 22.2 V 4200 mAh 6S 45 C Lipo Battery
Figure 16: Limit switch
Figure 17: Push button switch
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Figure 18: Smart Drive Duo-10
Figure 19: Schematic diagram for PCB in MR1
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Figure 20: Electronic Schematic design for MR2
2.4 Software Design
For controlling the MR1, we used 11 buttons with two analog triggers. The 11
buttons have included five of the digital buttons which are , , , and OPTIONS button,
two pressure-sensitive buttons which are L1 and R1 and four digital directional buttons.
Figure 21 has shown every single function of PS4 button that is used to control the MR1.
For the software design, there are some steps that the operator will do during the
competition. All the single steps are shown in Figure 22.
Figure 21 : PS4 DualShock 4
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Figure 22: Flow-chart for MR1 and MR2 movement
Figure 23: Plan for moving MR1 until passing the Gerege to MR2
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2.5 Calculating the Height for Launching the Shagai
Figure 24: Shagai launching
Refering to the rule which was given in ROBOCON competition 2019, the Shagai
must be able to travel 2 m on the horizontal displacement
1
2
h =u t + a t (1)
y
y
2
2
Given that h = 0.28 cm, ay = 9.81 m/s (since moving downward) and uy = 0 m/s, thus,
1
2
0.28 = (9.81)t
2
Since the horizontal and vertical times are constant and y horizontal projectile motion can
2
be assumed as 0 m/s
1 x
2
x =u t + a t and t = u x (2)
x
x
2
Substitute (2) into (1)
1 x 2 1 2
2
h = a ( ) 0.28 = (9.81)( ) ux = 8.37 m/s
y
2 u x 2 u x
After that, apply Newton’s Second law of motion, F = ma
Since the piston force which has been determined is 188 N and measured the Shagai
weight is 772 g and ux which has been determined above is 8.37 m/s. Therefore, substitute
all the related parameters into the equation of Newton’s second law of motion.
F 188
2
a = a = a = 243.52 m/s
m 0.772
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2
Based on what has been calculated above, the acceleration of 243.52 m/s must be
produced by pneumatic so that the Shagai is able to launch to 2 m horizontal displacement.
The initial speed of the pneumatic is 8.37 m/s. After considering the energy loss, air drag,
friction, the pneumatic is not hard to produce 8.37 m/s. Our launching mechanism idea is
not just placing the pneumatic cylinder horizontally but also using the theory of kicking the
ball. The idea of kicking ball is actually kick-started from ROBOCON 2018 shuttlecock
throwing mechanism.
Also, to prove that the calculation really works, TARUC ROBOCON team has also
made some data analysis for the launching Shagai mechanism.
3.0 DATA ANALYSIS
In this data analysis, the launching of the Shagai has been tried for 15 times. To
make the measurement more accurate, the Shagai was lifted up 28 cm from the ground and
the pneumatic system was provided by six bars gas tanks.
Table 2: Data analysis of the launching mechanism for the MR1
20 points 30 50 Passed without hit
Pass with hit
Trials (sheep, goat, points points the wall (sheep the wall (Tilt) Failed
tilt) (Camel) (Horse) and goat)
1 1 0 0 1 0 0
2 0 0 1 1 0 0
3 1 0 0 1 0 0
4 1 0 0 1 0 0
5 1 0 0 0 1 0
6 1 0 0 1 0 0
7 1 0 0 1 0 0
8 1 0 0 1 0 0
9 1 0 0 0 1 0
10 1 0 0 1 0 0
11 0 1 0 1 0 0
12 0 0 1 1 0 0
13 1 0 0 1 0 0
14 1 0 0 1 0 0
15 1 0 0 1 0 0
Total: 12 1 2 13 2 0
Table 3: Passing rate for launching mechanism
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Total Pass Rate: 100%
Total Fail Rate: 0%
Total Pass with sheep and goat: 66.67%
Total Pass with tilt 13.33%
Total Pass with camel: 6.67%
Total Pass with horse: 13.33%
Pie Chart For Launching
Shagai
Total Fail Rate:
13.33%
6.67% Total Pass with sheep
and goat:
13.33% 66.67% Total Pass with tilt
Total Pass with camel:
Figure 25: Pie Chart for launching Shagai
4.0 CONCLUSION, LIMITATION AND RECOMMENDATIONS
4.1 Conclusion
In summary, the results of the launching mechanism of the MR1 is perfectly fitted
to the theoretical idea with 100 percent success rate. The locomotion of both the MR1 and
the MR2 does works as designed and controlled. Therefore they successfully move and
crawl following the command from the commander through the PS4 controller.
4.2 Limitation
Due to its specific and restricted mechanical linkage, the MR2 cannot perform
turning mechanism. Instead, it can only crawl forward and backward by depending on its
uni-directional linkage.
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4.3 Recommendation
Due to time constraint, design mechanism for the MR2 is poorly developed.
Therefore, deeper, more intensive research and study should be carried out before designing
the MR2 mechanism.
5.0 ACKNOWLEDGEMENTS
As students of Tunku Abdul Rahman University College who are given the honour
to participate in ROBOCON Malaysia 2019, we would like to express our deepest
appreciation and gratitude to Dr. Lum Kin Yun and Mr. Johnny Tan Yong Li for their
relentless facilitation and good advice throughout numerous consultations. We also thank
our as well as lab technicians, especially Mr. Syafik, Mr. Syawal and others. We would also
like to extend our gratitude to all those who have directly and indirectly guided us in
completing the MR1, the MR2 and in completing this technical report. We also fervently
thank the Tunku Abdul Rahman University College for consent to use the labs, facilities
and the budget.
References
[1] C Semini, N.G. Tsagarakis, E. Guglielmino, M. Focchi, F. Cannella, D.G. Caldwell,
2011, Design of hyq, a hydraulically and electrically actuated quadruped robot,
Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and
Control Engineering 225(6):831–849. doi:10.1177/0959651811402275. URL:
http://pii.sagepub.com/content/225 /6/831.
[2] G. Endo, S. Hirose, 2012, Study on roller-walker—improvement of locomotive
efficiency of quadruped robots by passive wheels. Adv Robotics, 26:969–988.
doi:10.1163/156855312X633066
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PMJ Makers from Politeknik Mersing
TEAM SUPERVISOR: Mohd Nazrul Effendy Mohd Idrus
TEAM MEMBERS: Abdul Salam Saad
Mohd Khairul Anuwar Mohd Khairi
Zainuddin Mat Taib
ABSTRACT
Today, the application of robotic technology is rapidly expanding and getting more
important. Such technology is used to develop machine that can substitute humans and
replicate human action. ABU Asia-Pacific Robot Contest (ROBOCON) is a robot
competition organized every year. Each year the competition has different topics, but
generally speaking two or more robots must be used to complete the tasks. One of the robots
would be manually controlled while the others are automatic. In ROBOCON Malaysia 2019,
there are several tasks that have to be done by the manual robot. The first team to achieve
Uukhai is the winner. Therefore, there is a need to develop the Messenger Robot 1 (MR1)
and the Messenger Robot 2 (MR2) that can do the tasks and earn the points. The MR1 uses
Arduino platform to control the movement (move forward, backward, turn left, and turn
right) and mechanism (gripping, extending, and lifting). Furthermore, the MR1 have
adopted the pneumatic technology method as the mechanism for gripping, extending, and
lifting. While the MR2 also uses Arduino platform to control the movement (four legged)
and mechanism (gripping). The results of developing the manual robot for ROBOCON
Malaysia 2019 show that the MR1 is able to complete every task given. However, an
improvement has to be done to ensure that the robot is going faster than its current
performance.
1.0 INTRODUCTION
There have been previous studies that investigate problem-based and project-based
learning and its impact. Alternative learning methods and environments like project-based
learning are playing an increasingly important role in shaping the students for their future
professional life [1]. Every year, since 2003, undergraduate students from this Polytechnic
participate in the annually held ROBOCON competition organized by the national Asian
Broadcasting Union (ABU). Each year, a different problem statement is posed by the
hosting country and teams prepare robots on their own to solve it. The mission in the
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ROBOCON Malaysia 2019 match is to deliver information fast by using a relay messenger
system, the Urtuu system [2]. The system was first invented by the nomadic Mongolians. It
was an important invention that opened a new door to exchange and to share knowledge.
Based on this concept, ROBOCON Malaysia 2019 will promote the idea of Sharing of
Knowledge or in Malay, Perkongsian Ilmu. The slogan for ROBOCON Malaysia 2019,
“Satu Langkah, Seribu Lonjakan” is analogously derived from the horse stride in the Urtuu
system which travels far and beyond in relaying the messages.
There are several tasks in the competition to be completed. The MR1 carries the
Gerege from Khangai Urtuu, which is its starting point. It goes along the Forest, Bridge,
and crosses Line 1 before reaching Gobi Urtuu. Gobi Urtuu is the starting point of the MR2.
After the MR2 reaches the Gobi Urtuu, the MR1 passes the Gerege to the MR2. Once the
MR2 successfully receives the Gerege, it can go along the Gobi Area. The MR2 passes
through the Sand Dune and Tussock to reach Mountain Urtuu. After the MR2 reaches the
Mountain Urtuu, the MR1 may enter the Throwing Zone to throw the Shagai to earn 50
points or more. Once the MR1 earns at least 50 points, the MR2 is allowed to climb the
Mountain to reach Uukhai Zone. Once the MR2 reaches the Uukhai Zone, it raises the
Gerege and the match is complete. This is called Uukhai. The first team to achieve “Uukhai”
is the winner. Therefore, there is a need to develope a Messenger Robot 1 (MR1) and
Messenger Robot 2 (MR2) that can do the tasks and earn the points.
The MR1 was developed using omni wheel method movement while pneumatic
approaches are used for the lifting, expanding, gripping and throwing mechanism.
Playstation joystick control was used as the input to the controller of the MR1. For the MR2
legged mechanism, rotating legs using DC motor was used to manoeuvre to the selected
area. Infrared sensor is used as the input for the MR2 to start the movement of the robot.
As a conclusion, the MR1 and the MR2 were developed to accomplish the task of
ROBOCON. However, there is an improvement that have to be done for the MR2, epecially
on the legged mechanism to make it easy and smooth to rotate and move.
2.0 DETAILED DESIGN
2.1 Mechanical Design
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There are several mechanism designs developed for the MR1 and the MR2 to be
able to do the task given such as drive selection, lifting, expanding, gripping, throwing and
walking.
2.1.1 Messenger Robot 1
For the MR1 drive selection, four-wheel drive omni wheel method is selected to
manoeuvre the robot to the selected area (see Figure 1). The effect is that the wheel can be
driven with full force, but will also slide laterally with great ease.
Figure 1: Four-wheel drive omni wheel.
For lifting, expanding, gripping and throwing method, the pneumatic mechanism
approaches are used. The 5/2-way pneumatic valve is used to control the two-way cylinder
(see Figure 2).
Figure 2: 5/2 way pneumatic valve
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2.1.2 Messenger Robot 2
The rotating mechanism used for the MR2 walking method is shown in Figure 3.
The four legs are driven by DC motor for continuous rotation. The challenge in this
mechanism is to achieve rotating symmetry between each leg so that the robot stays balance
during walking.
Figure 3: Rotating mechanism legged (Single leg)
2.2 Electronic Design
In electronic design, the MR1 is manually controlled by the driver. While the MR2
is autonomously operated to accomplish the task.
2.2.1 Messenger Robot 1
Figure 4 shows the architecture of electronic design for the MR1. The main
controller for the MR1 is Arduino UNO controller. We have cascaded the UNO master to
the UNO slave in order to expand that number of input and output (I/O) of the UNO board.
Therefore, we have 40 I/O which can be used for 14 input and 21 output. The input for the
MR1 is from the wired PS2 joystick. The controller will process the input signal from PS2
and give the output signal to activate the omniwheel, servo motor and pneumatic cylinder.
Servo Motor
In the MR1, MG955 servo motor with the capability of rotating from 0 degrees to
180 degree is used. We control directly the servo motor from Arduino and not using servo
driver. This servo motor is used for gripping the Gerege and releasing it to the MR2.
Omni Wheel
Four Omni wheels are used based on the capability of the motor for sliding left and
right. DC geared motor 4G45Z 12 V is driven by DC motor driver MDC30 with rating 30
A. To control this motor driver, pulse width modulation (PWM) and direction of the motor
177
were given by the Arduino UNO controller to move the robot to go sliding left, sliding right,
turn left, turn right, forward dan backward.
PS2 Controller
PS2 controller is used as the input to the Arduino UNO. Already-built shield for PS2
is used because the control is much easy to use and more importantly user friendly.
Pneumatic Cylinder
Seven cylinders are controlled by Arduino UNO to control the mechanism of
gripping, extending, lifting and throwing. The operating voltage for each 5/2 valve solenoid
is 24 V. Therefore, there is a need to develop an interface circuit between Arduino UNO
and solenoid valve. Figure 4 shows the interfacing schematic circuit of ULN2803.
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J_24V
J_5V SIL-100-03
J_12V SIL-100-02
SIL-100-03
1 2 3
1 2
1 2 3
5V_P GND 24V_P
GND
5V_P 24V_P 5V_P 24V_P 5V_P 24V_P
GND
U1 J_S2 J_S3
J1 10 R1 J_S1 R2 1 R3 1
1 1 COM 18 1k 1 1k 2 1k 2
2 2 1B 1C 17 S_1 2
2B
2C
S_2
3 3 3B 3C 16 S_3 SIL-100-02 SIL-100-02
4 4 4B 4C 15 S_4 SIL-100-02
5 5 5B 5C 14 S_5 LED1 LED2 LED3
6 6 13 1000U 1000U 1000U
7 7 6B 6C 12 S_6 S_1 S_2 S_3
S_7
7B
7C
8 8 11
8B 8C S_8
SIL-100-08 ULN2803
5V_P 24V_P 5V_P 24V_P 5V_P 24V_P
J_S4 J_S5 J_S6
R4 1 R5 1 R6 1
1k 2 1k 2 1k 2
SIL-100-02 SIL-100-02 SIL-100-02
LED4 LED5 LED6
1000U 1000U 1000U
S_4 S_5 S_6
5V_P 24V_P 5V_P 24V_P
J_S7 J_S8
R7 1 R8 1
1k 2 1k 2
SIL-100-02 SIL-100-02
LED7 LED8
1000U 1000U
S_7 S_8
Figure 4: Interfacing schematic circuit of MR1
179
Wired PS2
controller
Servo motor
7 cylinder
4 Omiwheel
UNO
Power
supply
Figure 5: The MR1 electronic design
2.2.2 Messenger Robot 2
Figure 4 shows the architecture of electronic design for the MR1. The main
controller for the MR2 is the same as the MR2 using Arduino UNO controller. The input
for the MR1 operate based on the input signal from infrared sensor that is attached to the
Gerege gripper. The controller board will process the input signal and give the output signal
to activate the DC motor to drive the four legs.
Servo motor
Power
supply
Infrared
sensor
4 Dc Motor
UNO
Figure 6: The MR2 electronic design
2.3 Software Design
2.3.1 Flow-chart of Programming
Figures 7 and 8 show the programming flow-chart for the MR1 and the MR2
respectively. The MR1 controlled manually and has 10 inputs to operate the MR1. While,
the MR2 only have one input signal to operate autonomously.
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Start
MR1 move
Up
forward
MR1 move
Down
reverse
MR1 sliding
Left
left
MR1 sliding
Right
right
MR1
Triangle
gripping
Square MR1 lifting
MR1
Circle
extending
MR1
X
throwing
LEFTUP MR1 jacking
Gerege
LEFTDW
passing
End
Figure 7: The MR1 programming flow-chart
Start
Grip garege,
Sen1
move forward
End
Figure 8: The MR1 programming flow-chart
3.0 DESIGN OF MR1 AND MR2
Figures 9 and 10 show the MR1 and the MR2 design, respectively. The robot tends
to operate and complete the task given by ROBOCON Malaysia 2019.
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Figure 9: The MR2 design
Figure 10: The MR1 design
4.0 CONCLUSION
This report presents the technical process in developing the MR1 and the MR2. The
MR1 and the MR2 control use Arduino platform as main controller. Pneumatic approaches
are used as main actuator for lifting, extending, gripping and throwing of the MR1. While
the rotating legged robot is used to move the MR2. Therefore, the objective to develop the
MR1 and the MR2 has been archieved.
5.0 ACKNOWLEDGEMENTS
The author would like to thank the Department of Polytechnic and Community
College Education (JPPKK) and Mersing Polytechnic for financial support and providing
facilities for this project.
182
References
[1] Manvendra Singh Raghav, Shailesh Jain, and Subir Kumar Saha, 2008, Robotic competition
based education in eng. (roc-bee). Proceedings of NCMSTA 8.
[2] ABU Asia-Pacific Robot Contest (ROBOCON), 2019, Mongolia rulebook.
http://abuROBOCON2019.mnb.mn/en.
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MMU Cybertron from Multimedia University Cyberjaya
TEAM SUPERVISOR: Dr. Lo Yew Chiong
TEAM MEMBERS: Yang Lian Zheng
Ernest Yap Yong Yi
Eric Chin Kok Jun
Woon Wei Liang
Tan Chun Wei
Chan Chin Sen
Wong Pek Ling
Nicole Pay
ABSTRACT
The theme for ROBOCON 2019 is Great Urtuu- Sharing the Knowledge, In participating in
this competition, we are to design and construct two robots named as the Messengar Robot
1 (MR1) and the Messengar Robot 2 (MR2). The MR1 robot will have three working
omniwheels as its locomotion system, a short gripper supported by a short pole to hold the
Gerege and a pick-up mechanism to pick up the Shagai. An aluminium tray is placed below
the pick-up mechanism with a throwing mechanism in between. The MR2 robot consists of
four mechanical legs attached to four motors. There is also a small container fixed onto the
body of the MR2 to hold the Gerege. Both robots must follow a stringent set of rules
regarding the dimension, weight and other aspects.
1.0 INTRODUCTION
ABU ROBOCON, an abbreviation for Asia-Pacific Robot Competition, is an
international robotics competition specifically known as Asian-Oceanian College Robotic
Competition, founded in 2002 by Asia-Pacific Broadcasting Union (ABU). In the
competition, the robots will compete to complete a given task within a limited period of
time. The contest aims to create friendship among young people with similar interest who
st
will lead their countries in the 21 century. This will encourage involvement of aspiring
engineers and robot enthusiasts in the advancement of engineering and technologies.
The topic of Robot Contest (ROBOCON) Malaysia 2019 is Satu Langkah, Seribu
Lonjakan [1], where it describes ROBOCON Malaysia 2019 as the first step in improving
the Malaysian Education and in making sure it is in the good direction. The contest is held
in Dewan Sri Sarjana, Universiti Tenaga National with the main theme and slogan of Great
184
Urtuu - Sharing the Knowledge. There will be two participating robots which are labelled
the MR1 (Manual robot) and the MR2 (Autonomous). Both of these robots will compete
with other participating teams in real time. The task of the manual robot is to pass the Gerege
[2] to autonomous robot after it has passed a few obstacles. The autonomous robot will then
proceed to cross over the bridge, while the manual robot will begin throwing the Shagai [3].
2.0 DETAILED DESIGN
2.1 Mechanical Design
The structure of both the MR1 and the MR2 robots are made by using long aluminum
plates and aluminum pipes as their supporting frame.
2.1.1 The MR1 Robot
(a)
(c)
(b)
Figure 1: (a) Base frame, (b) Holonomic drive, and (c) Throwing mechanism
The base frame as shown in Figure 1 (a) is made hexagonal with three omniwheels
attached to its sides, making the bot holonomic.
185
The holonomic drive, shown in Figure 1 (b), has a motion with three degrees of
freedom to enable the robot to shift from side to side and to move diagonally without
changing the direction of the wheels. This allows smooth motion of the robot, while the
hexagonal nature of the structure provides stable and rigid stand for the mounting of the
pick-up and the throwing mechanism system. There is also a short grip that holds the Gerege
to be passed on to the MR2 robot. A short pneumatic cylinder is hidden in the hollow
aluminium pipe which will hold and release the Gerege.
The throwing mechanism, as shown in Figure 1(c), consists of a long aluminium tray
holding the Shagai in place, with a pneumatic cylinder placed below, in line with the Shagai.
The pick-up mechanism is mounted on top of the throwing mechanism with a DC motor as
the pivot, so that it will first hold the Shagai and place it on the tray and then back up to its
initial position. The throwing mechanism will follow up by throwing the Shagai in the
desired direction.
2.1.2 The MR2 Robot
Figure 2: The cuboid supporting frame
186
The cuboid supporting frame is made as such that it is shown and simulated using
Autodesk Fusion 360. With the working simulation of the motion of the robot, we designed
the dimension of the structure according to the specification as shown in Figure 2.
The four legs of the MR2 are powered by a motor each at the bottom of the frame,
with their extension fitted into a hollow shaft at the top that allows stronger support. A lever
is attached to the motor with an encase ball bearing installed on the other end.
Each motor will rotate its lever, driving the respective legs forward in order to induce
motion. The front right foot and the back left foot will have their motor running at 180
degree angle difference with the others so that the robot will be able to move forward
properly.
(a) (b)
Figure 3: (a) MR2 robot leg, (b) MR2 robot mechanism
2.2 Electronic Design
We have utilized different sensors for the MR2, which are the Infrared Sensor (IR
sensor) and an accelerometer, which enable the robot to adjust itself to a suitable position.
We also custom made our own mircocontroller boards with ATMEGA 328P, specifically
for both the MR1 and the MR2 robot to save cost, reduce wiring problems, and to use I2C
protocol [4]. These boards allow us to add PCB plug-in connector so we can connect to
lithium polymer battery.
187
2.2.1 The MR1 Main Board
(a) (b)
Figure 4(a) and (b): The main board for the MR1
The main board acts as the brain of the MR1. This replaces the need to use an
Arduino as the board is made to function similarly. The IO pins are designed and placed
conveniently to avoid messy wiring during the assembly of the robot. The custom made
board is evidently lighter than the original Arduino, since some unnecessary components
are not included which helps us reduce the overall weight of the robot. The board is
programmed so that it allows the robot to be controlled remotely.
Since these boards are powered by 12 V external power supply, a voltage regulator
circuit is added to get 5 V supply voltage to the mirco-controller.
The boards and schematics shown in Figure 5 are designed and fabricated with the
use of “Eagle” software.
188
Figure 5: Schematic design using “Eagle” software
189
2.2.2 The MR2 Motor Controller Board
Figure 6: The MR2 motor controller board
Four the MR2 motor controller boards are shown in Figure 6, each mounted on top
of a MD10C R3 motor driver. They are fixed onto a rectangular board at marked corners as
demonstrated in Figure 7. The Motor Controller Boards are used to programme the speed of
their respective motor, and to collect data from the encoder to ensure the position of the legs
of the MR2. This is crucial as it is the most important factor in ensuring that the robot is
able to move forward as we intended. Similar to the MR1 main board, the IO pins are
arranged to reduce wiring problems. The MR2 Motor Boards are “slaves” to the MR2
Motion Board.
Figure 7: The MR2 motor boards
2.2.2 The MR2 Motion Board
The MR2 Motion Board is designed to synchronize the movement of the four motor
systems. This Motion Board is connected to the four MR2 Motor Controller Boards, where
190
it will establish communication with each Motor Controller Boards through the utilization
of I2C serial bus protocol.
Figure 8: The MR2 motion board
I2C is a serial protocol for two-wire interface to connect low-speed devices like
micro-controllers, which is SCL (serial clock) line and SDA (serial data) line. This Motion
Board acts as the master device to the slave devices (Motor Controller Boards).
2.3 Software Design
Figure 9: The MR1 program flow-chart
Figure 10: The MR2 program flow-chart
191
2.4 Dimensions of the MR1 and the MR2
There are three pneumatic cyclinders used in the mechanical design of the MR1.
Compressed air pressure used is 6 kPa. The dimension is 98.5 cm x 75.2 cm x 68 cm (Height
x Length x Width). The weight of the MR1 is 10 kg
(a) (b)
Figure 11: (a) The MR1 and (b) The MR2
The drawing of the MR2 is done using Autodesk Fusion 360. Based on the design,
we can see that the structure and the locomotion of the robot allows smooth movement. The
dimension of the MR2 is 74.2 cm x 64 cm x 54 cm (Height x Length x Width). The weight
of the MR2 is 8 kg.
4.0 CONCLUSION, LIMITATIONS AND RECOMMENDATIONS
4.1 Limitation
The MR1 mechanism to pick up the Shagai is slightly big, although the overall
weight passed the contest rule, and the physical size is quite large which causes minor
problems in mounting the system. The compressed air in the plastic bottles for the pneumatic
escapes quicker than initially thought.
Due to limited resources, the feets of the MR2 do not have a very reliable suspension
system. Thus, this sometimes causes the robot to stagger, leading to an unsteady movement.
192
4.2 Recommendation
The Shagai pick-up mechanism in the MR1 can be made smaller in size; this can
help reduce the overall weight without affecting the performance as long as pneumatic
works fine. The tray need to lubricate regularly to reduce friction between the Shagai and
the surface.
It is important to have a good suspension system at the feet for the MR2 robot to
exhibit smooth and steady movement. Oil could be added to the joints to improve mobility.
4.3 Conclusion
ROBOCON Malaysia 2019 puts us to the test as we are challenged to think of ways
and ideas to materialize the design of the robots from scratch that are able to fulfil and
complete the given task.
The MR1 is able to exhibit smooth movement in every direction, with its pick up
mechanism being able to pick up the Shagai flawlessly. The throwing mechanism is able to
push the Shagai into the Throwing Zone without much effort and the Gerege gripper works
fine as well. The MR2 has also shown promising results as the robot managed to cross over
obstacles during the test run.
As we build the robot, we met with various problems to which we have worked out
different approaches in solving them. These experiences enhanced our technical knowledge
and skills as well as taught us team-work and professionalism.
5.0 ACKNOWLEDGEMENT
Team MMU Cybertron for ROBOCON Malaysia 2019 sincerely acknowledge all
the supports provided by advisor Mr. Lo Yew Chiong and his dedication in assisting and
mentoring us, without which the participation in ROBOCON Malaysia 2019 would not have
been possible. We would like to thank the Faculty of Engineering of MMU in providing us
the necessary electrical devices and equipments such as Laboratory Direct Current power
supply, the venue in which we were able to test run our robots. We hope that the Faculty
will continue giving us their support and accommodate our activities in future.
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Finally, the team would also like to thank all of the seniors who helped and guided
us in the early stage of building the robots, which greatly escalated the process in making
these robots to run successfully for the contest.
References
[1] About - ROBOCONMalaysia2019, 2018. Retrieved from
https://ROBOCONmalaysia.com/about
[2] Paiza – Wikipedia, 2018. Retrieved from https://en.wikipedia.org/wiki/Paiza
[3] Shagai – Wikipedia, 2018. Retrieved from https://en.wikipedia.org/wiki/Shagai
[4] I2C Info-I2C Bus, Inteface and Protocol, 2018. Retrieved from https://i2c.info
194
UTM from Universiti Teknologi Malaysia
TEAM SUPERVISOR: Mohd Ridzuan Bin Ahmad
TEAM MEMBERS: Tan Wai Liang
Lim Wei Sheng
Leong Lei Yeng
Ahmad Faiqal Haziq Bin Marzuki
Looi Kian Seng
ABSTRACT
This report summarises the mechanical design, electronic design and software design of the
two robots, i.e. the Messenger Robot 1 (MR1) and the Messenger Robot 2 (MR2) of
Universiti Teknologi Malaysia (UTM) ROBOCON Team for participating in ROBOCON
Malaysia 2019. In this report, we discuss how we design the robot in order to carry out each
task in the games, like passing and receiving of the Gerege from the MR1 to the MR2,
actuating the legs of the MR2, raising the Gerege at the Uukhai Zone, throwing of Shagai.
We also describe the connections between the sensors and the electronic board and the
function of certain sensors on the robots. The flows of the programme for the MR1 and the
MR2 are also displayed in this report. Some recommendations which can be applied in the
future for improving the robot designs are also summarised in the report.
1.0 INTRODUCTION
UTM ROBOCON Team was established since 2002. Our main focus has been on
developing robots and participation in ROBOCON activities. Participating in ROBOCON
Malaysia 2019 (adopted from Abu ROBOCON 2019) requires each team to develop two
robots, a wheeled robot and a quadrupled robot [1-4]. The quadrupled robot is a great
challenge for our team. In preparation for the national competition, research and
development have been carried out. This report describes the two robots (the MR1 and the
MR2) in terms the mechanism, electronic and programming. The objectives of developing
the robots are to participate in ROBOCON Malaysia 2019 and complete all tasks of the
games. The motivation for us to continue in developing the robots is to learn new knowledge
and skills especially on the quadrupled robot. Besides that, our motivation is to bring the
victory of ROBOCON Malaysia 2019 to UTM and represent Malaysia for Abu ROBOCON
2019 at Ulaanbaatar, Mongolia.
195
2.0 DETAILED DESIGN
2.2 Mechanical Design
For the MR1, a four-point omni navigation base is chosen because of the stability
and omni-directional movement is easier for passing through the Forest. Brushed motors
are used for the four-point omni robot. Pneumatic cylinder is used to grip the Shagai. Power
window motors are used to rotate the grippers of the Shagai onto the throwing platform.
Extension is used for throwing the Shagai to reduce the distance between the throwing
position and the Landing Zone, so that the accuracy can be increased. The extension and the
throwing of the Shagai is actuated by pneumatic cylinders. The Gerege is held above the
robot using a servo. When the servo rotates, it will release the Gerege from the high position
to the power position. The robot weights 32.4 kg with the dimension of 0.65 m x 1.4 m x
1.46 m.
For the MR2, eight power window motors are used to actuate the legs. The force of
the motors is transferred to the legs using gears. The gears on the robots are printed by using
3D printer. Rotary encoders are used to measure the movement of the legs. The arm for the
Gerege is held by using a hook, raised by using a spring and a servo. When the servo rotates,
it will release the hook and the spring will contract to lift the Gerege up. The robot has two
degrees of freedom. The robot weights 15.7 kg with the dimension of 0.95 m x 0.62 m x
0.64 m.
2.2 Electronic Design
Figure 1 shows the distribution of sensors and the architecture of the processing units
within the MR1 and the MR2 robots, respectively.
For the MR1, we used STM32F407VG [5] as main processor in our main-board and
robot navigation system. H-bridge power distribution module is connected to the main-
board in order to control the valve through the valve driver, servo, LED indicators and
motors for rotating part through motor drivers. For navigation, the motors are controlled by
robot navigation system through motor drivers. Motor driver is equipped with an emergency
button to enable power cut-off to the navigation when the emergency button is pressed.
Besides, the mode selector is used for mode switching in our main-board. Several
sensors such as analog sensors, laser sensors, limit switches, encoders, inertial measurement
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