INTERNATIONAL EFFICIENCY CHALLENGE
ELECTRIC VEHICLE RACES
TECHNICAL DESIGN REPORT
Delivery Date: 1 - 4 August 2021
UNIVERSITY: ERCIYES UNIVERSITY
VEHICLE AND TEAM NAME: VOLTAH2 – ENERJISTH2
CONSULTANT: ASST. PROF. SALTUK BUĞRA SELÇUKLU
TEAM CAPTAIN: EMRE ÖZDOĞAN
CATEGORY: ELECTROMOBILE HYDROMOBILE
CONTENTS
UNIVERSITY: ERCIYES UNIVERSITY ............................................................................................. 1
VEHICLE AND TEAM NAME: VOLTAH2 – ENERJISTH2 ............................................................ 1
CONSULTANT: ASST. PROF. SALTUK BUĞRA SELÇUKLU ..................................................... 1
TEAM CAPTAIN: EMRE ÖZDOĞAN ................................................................................................ 1
1. VEHICLE SPECIFICATIONS TABLE .................................................................................... 3
2. DYNAMIC DRIVING TEST...................................................................................................... 4
3. DOMESTIC PARTS ................................................................................................................. 4
4. MOTOR ...................................................................................................................................... 5
5. MOTOR DRIVER ...................................................................................................................... 6
6. BATARYA MANAGEMENT SYSTEM (BMS) ....................................................................... 7
7. BUILT-IN CHARGING UNIT ................................................................................................. 14
8. ENERGY MANAGEMENT SYSTEM ................................................................................... 24
9. BATTERY PACKING .............................................................................................................. 35
10. VEHICLE CONTROL UNIT (VCU) ....................................................................................... 41
11. DOOR MECHANISM ............................................................................................................. 54
12. MECHANICAL DETAILS ....................................................................................................... 55
13. FUEL CELL .............................................................................................................................. 76
14. FUEL CELL CONTROL SYSTEM ........................................................................................ 78
15. VEHICLE ELECTRICAL AND HYDROGEN DIAGRAM ................................................... 80
15.1 Vehicle Electrical Diagram ......................................................................................................... 80
15.2 Vehicle Hydrogen Diagram ........................................................................................................ 82
16. Cost calculation ....................................................................................................................... 86
3
1. VEHICLE SPECIFICATIONS TABLE
Feature Unit Value
Length mm 2687,9
Width mm 1241,1
Height mm 1172
Chassis Material Al 6063-T6
Shell Material Carbon Fiber
Brake System Hydraulic Disc, Front, Rear,
Handbrake Disc
Motor Type Ready-Made Gear Motor
Motor Driver Own Designs, Ready Product Domestic Product
Motor Power Kw 5
Engine Efficiency % %89
Electric Machine
Weight Kg 10
Battery Type Li-İon
Battery Pack Rated
Voltage V 50,4
Battery Pack
Capacity Ah 60
Battery Pack
Maximum Voltage V 58,8
Battery Pack Energy Wh 3024
Fuel Cell Power KW 1,2
Number Of Hydrogen
Cylinders # 1
Hydrogen Cylinder
Pressure Bar 2-10
Supercapacitor Ye Or No No
4
2. DYNAMIC DRIVING TEST
Dynamic driving test video has been shared in the link below.
https://sendgb.com/NsmGqVeuvQS
3. DOMESTIC PARTS
1. Motor Mandatory for Electromobile
and Hydromobile
☐
2. Motor Driver Mandatory for Electromobile
and Hydromobile
☐
3. Battery Management System
(BMS)
Mandatory for Electromobile
and Hydromobile
☒
4. Built-In Charging Dock Mandatory for electromobile ☒
5. Energy Management System Mandatory for hydromobile ☒
6. Battery Packaging Optional ☒
7. Electronic Differential Application Optional ☐
8. Vehicle Control System (VCS) Optional ☒
9. Fuelcell Optional ☐
10. Fuel Cell Control System Optional ☐
11. Insulation Monitoring Device Optional ☐
12. Steering System Optional ☐
13. Door Mechanism Optional ☒
5
4. MOTOR
Ready-made commercial geared motor with model number LEM-170-127 manufactured
by Lynch Motors will be used. The motor has a nominal operating voltage of 48V, a speed
of 3264 rpm and a torque of 16.2 Nm. Since the engine speed is above the required speed
for the vehicle, 1/4 gear transmission is used.
Thus, the engine speed was calculated as 816 rpm and the torque value as approximately
64.8 Nm. Technical data of LEM-170 motor is shown in figure 1, and efficiency, speed,
torque, and output power versus input current in figure.2. (Also see product data sheet.
https://www.lynchmotors.co.uk/pdfs/lmc-lem-170.pdf)
Figure 1: LEM-170’s Technical Data
Figure 2: LEM170’s Typical Technical Data Curve
6
5. MOTOR DRIVER
AXE 7234 model motor driver produced by Alltrax Inc. has been preferred. This motor
driver has been preferred because it meets the requirements of the motor to be used. It is
preferred because it is compatible with the motor operating voltage of 48V and meets the
starting current of the motor about 300A. Motor Driver Data is shown in table1. (Also see
product data sheet. https://alltraxinc.com/wp-content/uploads/2017/03/Doc100-004-
B_OP-AXE-Mini-Man.pdf)
AXE 7234 Permanent Magnet Motor Controllers
Battery Voltage 24-72 V
Current Limit 300 A
2 Minute Rating 300 A
5 Minute Rating 200 A
60 Minute Rating 125 A
Voltage Drop @ 100 Amp <0.16 V
Table 1: Motor Driver Data
7
6. BATARYA MANAGEMENT SYSTEM (BMS)
a) Circuit design
The curcuit down below which is curcuit design of BMS. Our BMS’s type is
passive balancing. This method is discharging from resistors. We see the LEDs instead
of discharging resistors which is providing balancing.
Figure 3.
Circuit has 4 section. First one is measurement section. We use resistors for
dividing voltage in the entry of BMS. Voltage divider provides us our battery pack’s voltage
measure in TTL(5V). After that we see analog Muxes which is 4067. These Muxes help
16 cells’ measurement in 1 ADC pin. Then we use voltage follower for get better signal for
amplification. The divided voltage from cell is amplifying by op-amp. PIC16F877A’s AN0
pin is connecting to op-amp which is amplified voltage for more resolution for ADC input.
8
This is the first section. We deal the battery measurement from picture down below which
is Figure 4.
Figure 4.
Now we will show section 2. Section 2 contains temperature sensor and
microcontroller. We are using LM35 for measure the temperature which is very cheap and
easy to use and helps microcontroller for more speed. Microcontroller is PIC16F877A. It
runs in 20MHz clock frequency which is maximum clock frequency for this model.
Microcontroller helps measure voltage levels and decides which cell needs discharge or
in critical situation. It drives the opto-couplers after that opto-couplers trigger mosfets what
drives resistor for discharging. Microcontroller helps to see what happens in system with
LEDs. LED green one indicates system is working. Orange LED indicates cells are
balancing and the last LED shows us there is critical situation in circuit. Working of BMS
is shown in Figure 5.
9
Figure 5.
Section 3 is about communication of BMS to vehicle control system unit. We can
understand what’s going on BMS. Vehicle control system shows to us information about
vehicle situation like BMS by screen in front of driver. We can see communication pins in
down below Figure 7.
Figure 6.
We came to final section. Section 4 balances cells. In this section, microcontroller
measures voltage level of cells and decides which cell has more charge. After that,
controller gives signal to opto-couplers to higher voltage level from others. Opto-couplers
switch MOSFETs which switches discharging resistors until higher voltage levels are
getting same voltage level from others. In this design we show LEDs instead of resistors
(we are driving LEDs by MOSFETs, opto-couplers aren’t driving LEDs). You should think
these LEDs discharging resistors. Section 4’s design is indicating in Figure 7.
10
Figure 7.
b) Balancing method
Cell-balancing circuits may be generalized into two categories: passive and active.
In passive cell-balancing circuits, energy is drawn from a cell having a higher SoC and is
dissipated as heat though a resistive circuit. While charging, current may be also
selectively routed around a cell having a higher SoC, via the resistive circuit, to avoid
further charging of the cell. Passive cell-balancing circuits may also be referred to as
dissipative cell-balancing circuits and such terms are used interchangeably herein.
Dissipative cell-balancing circuits are hardware efficient, generally requiring only a resistor
and a transistor for each cell, but typically waste energy in the form of heat. Our balancing
method is passive balancing.
An active cell-balancing circuit transfers energy from a cell having a higher SoC to
a cell having a lower SoC. Typically, the transfer of energy between cells is performed
indirectly through an energy storage element such as a capacitor or an inductor. Active
cell-balancing circuits may also be referred to as non-dissipative cell-balancing circuits
and such terms are used interchangeably herein. Active cell-balancing circuits are energy
efficient but are generally more expensive due to the cost of inductors and/or capacitors
and the need for extra wiring to transfer energy between the cells.
11
c) Control algorithm
We choose flowcharts to understand our BMS how it works.
Figure 8.
12
d) Simulation studies
In figure 7 we can see how we discharge cells. There are switches for opto-couplers
to drive MOSFETs. If we close any switch what will drive to related cell’s resistor consume
energy for discharging. The switches will be MCU’s pins. We just try to show mechanics.
We use Multisim software for simulation.
Figure 9.
e) Printed circuit studies
There’s our BMS’s PCB design. We designed with Altium Designer.
Figure 10.
13
f) Production studies
We didn’t print our BMS design. Give an order to Manufacturer. We assembled
BMS with related devices.
Figure 11.
Figure 12.
14
7. BUILT-IN CHARGING UNIT
Circuit Topology
The circuit topology of our vehicle's battery charger has been selected as half bridge. First,
we convert the 220V AC voltage from the network to 310V DC voltage with bridge diode.
What is required for the battery is the charging unit, which outputs at 600W at 60V voltage.
To operate the PWM control integrate, we convert the AC voltage we receive through the
transformer to 15V AC voltage. Here we again convert 15V AC voltage to 21V DC voltage
using bridge diode. Then we convert the voltage to 12V voltage with the voltage regulator
7812. We're sending the 12V voltage out of here into the integrate. Then comes the
location where the PWM signal needed for the trigger of the circuit is produced by SG3525
and the signal produced by the IR2110 MOSFET drive is applied to the MOSFET gate.
The frequency of the generated PWM signal depends on the resistance and capacitor
values of the SG3525 connected to the T and CT ends, where the output voltage can be
changed by changing the frequency. We're working at a frequency of 50 khz. When
MOSFET works like a switch, a current is cut and discharged 50,000 times per second
through the transformer, creating a variable magnetic field on that transformer 50,000
times per second. In this variable magnetic field, the current is induced in secondary
windings so that the desired voltage is obtained according to the number of bandages.
Finally, the voltage directed by fast diode and capacitors passes through the LC filter to
show the output voltage. The selected topology is half bridge topology and there is also
feedback of the circuit. The Pin 10 of the SG3525 is used to provide overcurrent
protection. Lithium batteries will be fed the battery management system in accordance
with the charging methods. The circuit was simulated, PCB design was made and copper
plaque was printed.
The circuit consists of four parts in general;
Fig.13: 220V AC voltage is converted to 310V DC voltage with the help of bridge diode
15
Fig.14: The part where the PWM signal is produced, the signal mosfets produced with
the IR2110 integration continue.
Fig.15: When the mosfets work like keys, a current is generated through the transformer
that is cut and drained 50.000 times per second, which induces the current in the
secondary windings within the magnetic field.
16
Fig.16: The voltage obtained at the exit is re-directed, the bridge is filtered with the help
of voltage capacitors pointed with the help diode
Primer Winding Turn Calculation
Parameters to be used for winding number;
Np= Number of turns for primer winding
F=Operation frequency (50000 Hz)
Ae=Core area (çekirdek alanı) (3.68 mm^2)
Bmax=1800 Gaussian mean value was obtained.
Magnetic flux constant for ferrite core = 4
Nominal voltage= 220*1.41=310V
Half Bridge Topology for voltage calculation = 310/2=155V
Common equation;
N_p=(155*〖10〗^8)/(4*50000*1800*3,68)≅11
The number of turns in the primary part was set to 1 * 11.
17
Secondary Winding Turn Calculation
Parameters to be used for winding number;
Ns= Number of turns for primer winding
F=Operation frequency (50000 Hz)
Ae=Core area (çekirdek alanı) (3.68 mm^2)
Bmax=1800 Gaussian mean value was obtained.
Magnetic flux constant for ferrite core = 4
Vout=60V
Common equation;
60=4*1800*3.68*50000*〖10〗^(-8)*N_s
From here N_s≅ 5 is calculated. Because the circuit has a symmetrical feed and the
wires of the secondary windings are wrapped in 2 * 5 turns so that the cable can resist
current.
Fig.17 Altium circuit drawing
18
Fig.18 Altium pcb drawing
Fig.19 PWM controller simulation
19
Fig.20 Mosfet simulation
Fig.21 Simulation of running the transformer
20
Fig.22 Printed circuit board
Fig.23 Integrated square wave output
21
Fig.24 Production studies
Fig.25 Production studies 2
22
Fig.26 310V DC output
In addition, component work files are shared via the link below.
https://www.sendgb.com/upload/?utm_source=JGgQAXy612r
Before Design Current Design
Circuit Design : - Half-Bridge
Power Level : - 540W
Output Voltage Range : - 60-70 DC V
Output Current
Oscillation :
- 8A
Input Power Factor : - 220ACV
Power Cycle Efficiency : - 0.879
PWM Control Integration : - SG3525
Protection Circuits /
Elements :
- -
Printed Circuit Size : - 212mm x 204mm
23
Fig.27
24
8. ENERGY MANAGEMENT SYSTEM
Control Algorithm
The energy management system to be used in the vehicle will be converted into two
power sources and DC-DC, which will deliver the voltage levels for these sources. The
location of the power supplies and DC converters in the vehicle is in figure-28.
The nominal operation of the Fuel cell, which is one of the sources, is 26V. Rated motor
operation is 48V. Fuel Cell Voltage Level the Voltage booster DC converter at the power
level required for the motor to run will increase the Power Cell Voltage to 48V.
Battery pack, another power source, is nominal 50.4V. But reasonable usage is 58.8V,
with a minimum of 28V.
Figure 28.
Since the nominal voltage of the power supplies in the topology is different, a converter
was needed to equalize each other. Since the use of converters for both is not good in
terms of efficiency, we designed a Boost type converter to equalize the fuel cell voltage
in our system with the battery pack. Figure-29. Again, we preferred the Boost converter
in terms of losses and efficiency.
25
Figure 29: First topology diagram
Figure 30: Initial topology Mosfet(gate) simulation
26
In the R&D studies in the first topology section, competence was tried to be established
in the subjects of boost converter and PWM design, which are the main requirements in
the system.
However, since only a boost converter would not be enough and it would be required for
the communication between sources, which is the main purpose of the energy
management system, there were options to design a system that would both generate a
pwm signal and control voltage by a smarter system (microcontroller) or an integrated
system. We preferred to design a voltage-controlled system. we did.
Circuit Design
Figure 31: Circuit diagram
If we talk about the IC, the control section consists of 1IN+(1), 1IN-(2), 2IN+(16), 2IN-
(15), DTC(4), FEEDBACK(3) and Output Control(13).
As seen in the block diagram, it contains 2 internal operational amplifiers (error amp 1-
2). These operational amplifiers can be used as error amplifiers or as comparators if
desired. The key difference between an amplifier and a comparator is that the amplifier
has a gain. In general practice, one of these op-amps is used as a comparator to limit
the transistor current, while the other is used to regulate the output voltage by forming
an amplifier with the FEEDBACK pin. As seen in the diagram, the FEEDBACK pin is
connected to the outputs of the op-amps. Thanks to this connection, a gain op-amp
circuit is created using a feedback resistor and it is possible to control the voltage in
smaller ranges.
27
Figure 32: Example Comparator design and amplifier design
According to the variable battery voltage in our designed circuit, a design that keeps the
EMS output voltage equal to the battery has been realized. In variable battery voltage, it
can be kept at the same level thanks to the frequency value changing with the voltage
Figure 33.
FUEL CELL VİN BATTERY VİN EYSOUT
33 51 51
20 51 51
25 43 43
27 37 37
Table 2: Equality check with randomly entered data
28
Simulation
Figure 33: EMS output 1485W
Figure 34: Mosfet gate trigger
29
Figure 35: Test part set up for frequency variation by changing the battery voltage, which
is the reference voltage
Altium Designs
Figure 36: The oscillator circuit set up for the integrated
30
Figure 37.
Figure 38: Transistors and triggered Mosfet to power the TL494 trigger
31
Figure 39: Voltage dividers and power sections
Figure 40: Altium pcb design
32
Development And Test Results
The randomly entered data given in Table 1 and the actual results and test stages of the
equality control studies are given in Figure 41 and Figure 42.
Since the sources are in the testing phase, they are included in the test as power source
(battery) and battery (fuel cell).
Figure 41: Fuel Cell Voltage
33
Figure 42: The voltage taken from the power source used instead of the battery and the
measured EYS output voltage.
34
Figure 43: Cooler used against Mosfet and Diode heating.
Figure 44: Printed circuit stage.
In addition, component work files are shared via the link below.
https://www.sendgb.com/upload/?utm_source=JGgQAXy612r
35
Previous Desing Current Desing
Circuit Topology : - Entegre kontrollü boost
Power level : - Max:1400W
Input Voltage Range
:
- Fuel cell Minimum in:24
Fuel cell Max:40
Battery min:28
Battery max:58.8
Output Voltage Range :
- EYS min:28
EYS Max:58.8
Power Cycle Efficiency : - %70
PWM Control Integration : - TL494
Semiconductor Power
Switches :
- IXFH320N10T2
Protection Circuits /Elements : - 100 amp fuse
Printed Circuit Size : - 10CM-15CM
-
9. BATTERY PACKING
Batarya paketini oluştururken kullanacağımız motorun akım, gerilim değerlerine ve yeni
yarışacağımız pistle ilgili yaptığımız hesaplamalara bağlı olarak sonuca vardık.
Seçtiğimiz hücrenin nominal voltajına, devamlı deşarj akımına ve yaptığımız ısıl
analizlere bağlı olarak 14 seri 10 paralel bir batarya paketi oluşturduk arabada 2 adet
paralel bağlı batarya paketi kullanacağız.
Kullanacağımız batarya hücresine ait datasheet:
https://www.batteryspace.com/prod-specs/9989.specs.pdf
36
a) Cell Properties:
Battery Material Li-On
Manufacturer LG
Nominal Voltage 3.6v
Minimum-Maximum Voltage 4,2v/2v
Rated Capacity (25 Degrees) 3000 mAh
Cell Weight 47 g
Continuous Discharge Current 10A
Maximum Discharge Current 20A
Cell Dimensions Ø18 X 65
Operating Temperature -20 ~ 60℃
Table 3: Cell Data
b) Specification Of Package:
Cell Capacity 1512 Wh
Number Of Cells 140 Adet
Total Weight 6580 Gr
Max Voltage 58,8v
Nominal Voltage 50,4v
Minimum Voltage 28v
Continuous Discharge Current 100A
Maximum Discharge Current 200A
Table 4: Package Data
37
c) Specifications Of Package Material:
Material Name PVC
Shrinkage Temperature 80℃
Melting Temperature 105℃
Rated Voltage 300v
Table 5: Package Material Data
d) Thermal Analysis Of Battery Modules Or Package:
Figure 45: Thermal Analysis Results With COMSOL Multiphysics
38
e) Placement And İsolation Of Modules And Packages:
Figure 46: Battery Cell
Figure 46: Battery Module Solidworks Drawing
39
Figure 47: Battery Module Punting Operations
Figure 48: Packaging Operations
40
Figure 49: Battery Module Final State
f) Battery Cooling System Design:
Figure 50: Battery Cooling System Design
41
10. VEHICLE CONTROL UNIT (VCU)
VCU Function:
The vehicle control system includes elements such as microcontroller, voltage regulator,
sensors, display, and relays. For the vehicle control system to control the vehicle, these
elements are harmoniously integrated among themselves.
An VCU is manufactured to control the front and rear of the vehicle. Two Arduinos were
used for the front and rear sides of the vehicle control system. SPI communication was
used for the communication of these Arduinos. Buttons, relays, headlights, and horns are
located at the front and a screen is used to transmit sensor data to the driver at the front.
Sensors are used in the rear to obtain values such as speed, temperature and current.
Voltage regulator is used to ensure the voltage that the system needs to operate. UDEA
Rf module was used to send information that needed to be monitored, such as sensor
data, to the computer at base station. Battery stabilization status, battery and cell
measurements will be carried out by BMS and communicated with VCU and displayed on
the screen. VCU is manufactured locally.
Main functions:
a) In-car communication system
SPI communication protocol is used for communication between Arduinos used for front
and rear side. SPI protocol was also used to communicate with other components of Car
such as Bms , Ems etc.
b) Monitoring the vehicle status and communicating it to the user
The information received and processed from the sensors is shown on the Nextion screen
and the information is displayed to the user.
c) Transfer of vehicle data to the monitoring center
Transfer of data from sensors to vehicle monitoring center by using telemetry.
42
Component Selection
Microcontroller:
Figure 51: ATMEGA328P Processor
The ATMEGA328P processor has been selected for the vehicle control unit.
ATMEGA328P is a processor designed with Atmel's RISC architecture. It has high
performance and low power consumption. It works range from -40 degrees to +85
degrees. It works with feed from 1.8 V to 5.5V. Supports communication protocols such
as SPI and I2C. Due to these features, the ATMEGA328P processor for VCU has been
used.
Display:
Figure 52: Nextion Display
43
Nextion display is used as a screen in the vehicle control unit. Communication with the
processor via serial port was provided. Due to its ease of use and compatibility with the
processor we use, it has been selected as a display for the vehicle control unit.
Temperature Sensor:
Figure 53:D S18B20 Temperature Sensor
The Ds18b20 temperature sensor is selected to measure the temperature in the vehicle
control system. The Ds18b20 temperature sensor is a digital sensor. The biggest factor
in selecting this sensor is that the sensor is sensitive, waterproof and has a digital sensor.
The discovery of the Arduino library provides ease of use. Used with 4.7k ohm resistance
connection for communication between Arduino and sensor.
Hall-Effect Sensor:
Figure 54: Hall-effect 3144E sensor
44
The hall-effect 3144E sensor was used to determine the vehicle's speed information. It is
the sensor that produces digital signals with a magnet located on the inside of the wheel.
In each round, the magnet activates the sensor, and a cycle is read on the processor. The
information read is replaced in the speed equation and the speed information is obtained.
Experimental Studies
1) Communication Protocol:
The SPI communication protocol for the vehicle is preferred for reasons such as being
faster, more efficient, and more functional than I2C like communication protocols. Rear
and front system communication simulation is shown in figure 55 and figure 56 shows
the communication experiment.
Figure 55: Schematic connections for SPI communication
Figure 56: SPI communication Proteus simulation The data package that was formed
was sent from master Arduino to slave Arduino
45
Figure 57: installation and operation of the simulated circuit
2) Sensor Experiments:
Sensor studies are primarily simulated on the proteus. Then, circuits were installed on the
breadboard and the experiment was carried out. Figure 58 is a single sensor
measurement and communication experiment, figure 59 and figure 60 sensor
experiments and outputs are seen.
46
Figure 58: Sending temperature data with SPI
(a)
(b)
Figure 59: Performing the temperature sensor experiment(a) and (b) output.
47
Figure 60 shows the experiment in which circuit temperature sensor and potentiometer
data were obtained. The potentiometer represents the data to be taken from the current
sensor.
(a)
(b)
Figure 60:. Conducting temperature sensor and potentiometer experiments(a) and (b)
output.
Temperature sensor and potentiometer data are obtained and shown on the LCD
screenas shown in figure 61.
48
Figure 61: Nextion display and circuit
3) Warnings and Signs
Warnings such as High Temperature and Low battery voltage are displayed in the lower
left corner of the screen. In case of High Temperature Warning (When the Safe
Temperature Limit Specified in the Rules is Exceeded), the Horn and Flasher got
activated. In addition, vehicle shutdown occurs when a Higher Critical Value is Exceeded.
Bms operating status is displayed in the lower right corner of the screen. BMS operating
status is indicated in 3 different colors. If the balancing situation is successfully terminated,
the green light will be displayed on the screen in case of continuing balancing, yellow light
and balancing, or an error in the BMS card. AKS tool screen shape. Shown in '62.
49
Figure: 62 AKS Vehicle display Image
Telemetry:
With the RF module in the rear system, temperature, current, voltage, speed information
was transmitted to the computer interface on the receiving side. UDEA UFM-A12 WPA
has been selected as rf module. The circuit required for UDEA operation is located built
into the AKS card. It consists of two parts: Receiver and Transmitter. Transmitter in Figure
63. In 64, the receiving System is shown.
Fİgure. 63 RF Module Transmitter Part Circuit
RF modules require two separate feeds, + 5V and + 3.3V. Two voltage regulators are
used to meet two different RF voltage GDI interface modules. + 5V output Max232, the
RF module feed, adjustable voltage regulator integrates to the LM317. LM317 voltage
regulator 3.3V resistance output voltage R1 and R2 resistors are set to apply to the 3.3V
voltage input to the RF module. The telemetry module in the vehicle is communicated with
the Arduino in serial and transmits the data to the receiver module.
50
(a)
(b)
Figure 64. RF Receiver (a)schematic and (b) PCB design
51
Figure 65. Pin Assignment to Atmega328
Figure 66 Control unit and communication ports
52
Figure 65 VCU main card 3D Model
Figure 66 Front Card (Dashboard) 3D model
In addition, component work files are shared via the link below.
https://www.sendgb.com/upload/?utm_source=JGgQAXy612r
53
Previous Design Current Design
VCU Functions : -
Speed Measurement,
Transfer of Vehicle Data
to the Monitoring Center,
Temperature
Measurement, Current
Measurement, In-Vehicle
Communication System,
Monitoring of Vehicle
Status and Transmitting
to the User
Controller Integrated
Circuit : - ATMEGA328P
Number of VCU I/O : - 23
Electronic Circuit
Design : -
Microprocessor and
semiconductors are used
Printed Circuit Board
Design : - SMD-TH mix
Printed Circuit Board
Production : - Handmade
Software Algorithm : - Atmel Atmege 328P
based.
Experimental Study : -
Experimental Study Has
Been Performed On
BreadBoard
Size (PCB/Box) : - 110x130 mm
54
11. DOOR MECHANISM
Figure.67Door lock mechanism design
55
12. MECHANICAL DETAILS
T
Figure.68 Vehicle mechanical dimensions
Aerodynamic of car:
(a)
Hydromobile
56
(b)
(c)
Figure.69 (a) Pressure contour side view, (b) Streamlines at 30 m/s, (c) drag coefficient
graph
The flow can be described by Navier-Stokes equation:
(1)
57
Rollbar & Rollcage design:
The rollbar & rollcage design was realized using SolidWorks. The model is realized by
means of tubular frame, having external dimension 30mm and wall thicknesses 3mm.
Figure 70: Rollbar & Rollcage design
Figure 71: Rollbar & Rollcage welding process
58
Strength analysis:
Strength analysis was performed using ANSYS Workbench. The roll bar height
dimensions are given in Figures.
Figure 72. Rear rollbar measures
Figure 73. Front rollbar measurements
When the point load is applied between the lowest point and the upper point of the roll
cage; 1kN was the calculated force in the horizontal direction . The analysis of the
59
amount of displacement as a result of the rollbar force to the front and rear H / 200 has
been shown. Both calculations are made for the front and rear rollcage (H: The
difference in height between the bottom point of the top spot).
Figure 74. Orientation and fixation points at which the force is applied
Figure 75. Mesh structure
60
Figure 76. 1000 N horizontal load status
Figure 77. Total 1000 N deformation amount when loading in Z direction
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Figure 78. Z total deformation amount according to the force applied through
As shown in Fig. 42, a maximum deformation of 3.02 mm occurs under a load of 1 KN
when applied in the Z direction. In this case a horizontal loading of the rollbar and
rollcage design tools (Displacement a>b) it is seen that it is within the limits defined
as safe. Applied to the top spot in the rollcage, strength analysis showed 40kN applied
load under the point when tested in buckling of the rollbar sprain.
Figure 79. 40000 N. -Y direction load status
62
Figure 80: the amount of deformation occurring in the direction -Y
Figure 81: corresponds to the load direction of the -Y - Von misses stress values
As shown in Figure, if a load of 40 kN is applied in the Y direction, a maximum of 0.6
mm deformation occurred on the roll cage. 3 mm deformation maximum total
deformation can be seen.
Outer Shell Production:
The shell was produced in the team laboratory together.
Stage 1: The outer shell of our vehicle is drawn in SolidWorks as shown in Figure x.
The shell production stage is as follows:
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Figure 82: Outer shell of vehicle
Stage 2: Using 3D CAD Data of our drawings, a block of expanded polystyrene is cut up
into into 3 parts (with a density of 30%) using a hot wire.
Figure 83. Cut with a hot wire EPS
Stage 3: Using CNC code we formed the shell structure from the EPS material.
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Figure 84. Starting material models (EPS)
Stage 4: Epoxy molding phase of EPS was used. The water-based putty was then
applied on the CNC machine 4 times.
Figure 85. Water based putty coating on model material.
Stage 5: After that fiberglass reinforcements were added and we obtained a hard shell.
65
Figure 86. Obtaining hard shell material from EPS
Stage 6: Vehicle modeling is completed after abrasive lining on top of the glass fiber.
Figure 87. Car model
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Stage 7: The model was created by putting steel paste onto a smooth surface. Then the
female mold is made of polyester fiber glass fabric by applying a model bond
Figure 88. Fiber Glass Mold
Stage 8: The carbon fiber, peel ply fabric, vacuum net are placed on top of each other
in the fiber glass mold which is made smooth.
67
Figure 89. Vacuum Infusion Preparation
Stage 9: Sealing is provided and covered with vacuum bag. Then vacuum pump and
epoxy connectors for infusion are placed on the mold.
Figure 90. Vacuum infusion
Stage 10: We applied the epoxy and the excess was withdrawn using vacuum pump.
Then the required heat treatment was applied and the body removed from the mold.
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Figure 91. Body produced by vacuum infusion method
Stage 11: Cavities needed for wheel parts, windows and wind shield were cut
and the necessary parts added by our team. The outer shell reached its final
state.
Figure 92. Final state of the body
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Chassis Analysis
When we make the required fixations in this pressure analysis made for the chassis and
put it on the load of 2500 N, our values are between 1 N / m ^ 2 and 2 N / m ^ 2 as seen
on the pressure graph. This indicates that our chassis is durable in the loading situation.
Figure 93: Chassis design
Figure 94. Chassis von mises stress
In this displacement analysis made for the chassis, necessary stabilizations are made and
when put on 2500 N load, as shown in the displacement chart, our value is max. 1.11 mm
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displacement. We decided that our chassis was appropriate because it was worth ignoring
the relocation.
Figure 95. Chassis total displacement
We can see that there is not much deformation in this case because it is between 0 and
2 as it is seen in deformation (distortion) chart when 2500 N load is placed on the load
region.
71
Figure 96. Chasis volumetric strain
Support and axle tree analysis:
The pressure analysis for the left-hand motor housing shows that when we put on the 750
N load, the value is 0 N / m ^ 2 and 1.5 N / m ^ 2, as shown in the pressure graph, which
indicates that our motor housing is durable.
Figure 96. Left support von mises stress
72
In the displacement analysis for the motor carrier on the left side, necessary fixings are
made and ... When placed on 750 N load, as shown on the displacement chart, our value
is max. 0.07 mm displacement. We decided that our motor housing is appropriate because
it is a value that can be neglected.
Figure 97. Left support total displacement
We can see that there is not a lot of deformation in this case because we have made the
necessary stabilizations in the deformation analysis of the motor housing on the left side
and the value is between 0.5 and 1.5 as seen in deformation (distortion) chart when 750
N is placed on the load.
73
Figure 98. Left support volumetric strain
When we make the necessary fixings in the pressure analysis made for the wheel carrier
on the right side and put it on 750 N load, our value is 0 N / m 2 and 1 N / m ^ 2 as seen
on the pressure graph. This indicates that our wheel loader is durable in the load case.
Figure 99. Right support von mises stress
74
In the displacement analysis for the right side tackle carrier, necessary fixings are made
and when the load is placed on 750 N load, as shown in the displacement chart, our value
is max. 0.02 mm displacement. We decided that our car housing was appropriate because
it was a value that could be neglected.
Figure 100. Right support total displacement
We see that there is not a lot of deformation in this case because we have made the
necessary stabilizations in the deformation analysis of the wheel carrier on the right side
... and when we put 750 N on the load, our value is between 0.5 and 1.5 as seen in
deformation (distortion) chart.
75
Figure 101. Right support volumetric strain
76
13. FUEL CELL
The fuel cell will be used as a commercial ready product. The product is the Nexa 1200
Fuel cell module, produced in partnership with Ballard and Heliocentris in the early
2000s. The Nexa 1200 Fuel cell module produces an irregular DC output of up to 1200
Watts at a nominal output voltage of 26VDC. By using an external fuel supply,
operation is continuous. Using hydrogen fuel, the Nexa™ module is extremely quiet
and allows indoor operations with zero emissions. Figure.102 shows Nexa 1200 Fuel
Cell module and Figure.103 shows Polarization and power curve. Figure.104 shows
Cell Input-OutpuIİnformation. (Also see product data sheet.
https://drive.google.com/file/d/12w3GEPU_aKDS9DclPKVHxWKYwLyNaGdA/view?u
sp=sharing)
Fig.102 Nexa 1200 Fuel Cell module
77
Fig.103 Nexa 1200 Polarization and Power Curve
(a)
78
(b)
Fig.104 Fuel Cell (a) Output and (b) Input Information
14. FUEL CELL CONTROL SYSTEM
There is a built-in control system on the Nexa 1200 Fuel cell module. This control
system ensures safety and system stability. The Nexa 1200 Fuel cell module contains
all the auxiliary equipment necessary for the operation of the fuel cell as well as the
fuel cell. Auxiliary subsystems include hydrogen distribution, oxidizing air supply and
cooling air supply. Built-in sensors monitor system performance, and the control board
and microprocessor fully automate operation. The Nexa™ system also includes
operational safety systems for indoor operation. By making computer communication
with the fuel cell control card, instant data can be recorded, and performance can be
monitored through graphics. Figure.105 shows the system diagram of the Nexa 1200
fuel cell module and figure106 shows the fuel cell control system.
79
Figure.105 Nexa 1200 System Diagram
Figure 106 Nexa 1200 Fuel Cell Control System
80
15. VEHICLE ELECTRICAL AND HYDROGEN DIAGRAM
15.1 Vehicle Electrical Diagram
(a)
81
(b)
Figure 107 Vehicle (a) Electrical Diagram (b) placement
82
15.2 Vehicle Hydrogen Diagram
Vehicle hydrogen installation diagram is shown in fig.Figure 108.
Figure.108 Vehicle Hydrogen Diagram
The certificates submitted by the supplier company of the products such as Regulator,
Solenoid Valve, Check Valve, Relief Valve, Flame Trap to be used in the hydrogen
installation are shown in the figure.109 and figure.110.
S le i
alve
I :0-40 ar
ut:0-10 ar
Pressure
Regulat r
la e
Tra
1 ar
Relie
alve
C e
alve
y r ge
l eter
uel ell
I ter al
Relie
alve
uel ell
I ter al
S le i
alve
uel ell
I ter al
Pressure
Regulat r
uel ell
Ballar
Ne a
1200
uel ell
I let
Metal y ri e
Ca asity:1 00N
Pressure:2-10 ar
Sa ety
alve
83
Figure.109 Certificate for Products to be Used in Hydrogen Installation
84
Figure.110 Certificate for Products to be Used in Hydrogen Installation
85
The metal hydride tank, which is purchased from the Bulgarian tank company Labtech
Hydrogen that has 1500N Liter Hydrogen capacity and 25 SLPM output flow, which can
operate in the pressure range of 2-10 bar.
Şekil.111 HBond1500L Metal Hydride
86
16. Cost calculation
Product Name Quantity Price(TL)
Fuel Cell 1 Pcs 90.000 TL (Sponsorship)
MetalHydride HBond 1500L 1Pcs 17.583,29 TL
Motor 1 Pcs 28.000 TL (Sponsorship)
Vechile Control Unit 1 Pcs 3.980 TL (Sponsorship)
Energy Managementy System 1Pcs 4.760 TL (Sponsorship)
Built-in Charge Device 1Pcs 2.760 TL (Sponsorship)
Motor Driver 1Pcs 9.000 TL (Sponsorship)
Seat 2 Pcs 6.200 TL (Sponsorship)
Fiberglass 45m2 2.485 TL (Sponsorship)
Brake System 2 Pcs 6.425 TL (Sponsorship)
Steel Whell Rim 5 Pcs 3.980 TL (Sponsorship)
Battery Management System 1 Pcs 3.427 TL (Sponsorship)
Hydrogen İnstallation 7.426 TL (Sponsorship)
Mechanical Repair 6.250 TL (Sponsorship)
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