Vehicle Surrounding Supervision

Canadian Journal on Computing in Mathematics, Natural Sciences, Engineering and Medicine Vol. 3 No. 7, December 2012

277

Vehicle Surrounding Supervision

Jer-Vui Lee, Yea-Dat Chuah, Eric C.H. Tan, Yee-Chuan Lau, En-Yen Phang, Chor-Zheng Tan, Chun-Sien Teh

Abstract — The objective of this project is to design a

mapping system which displays the surrounding of the vehicle

by using ultrasonic sensor and graphical user interface (GUI)

which provides maximum vehicle’s surveillance. Its

mechanical and electronic hardware implementations as well

as Java programming are discussed in this paper. 33 series

dsPIC from Microchip Inc. is used in this system to work as

peripheral interface between ultrasonic sensor, buzzer and

Java-compatible-display device. Ultrasonic sensor rotated by

drive of servo motor to achieve certain sensing coverage. PIC

processes the sensor output and transfers this data to Java

platform. A developed Java program is used to acquire and

process the data from PIC, map the vehicle surrounding and it

is displayed in graphics via the GUI. In addition, the casing of

sensor is attached on a surface of car by using magnet and

designed to allow the sensor to move within 180º (sensing

coverage).

Key Words — Vehicle supervision, mapping system, Java

programming and PIC.

I. INTRODUCTION

The number of cars on the road has been increasing tremendously since

few decades ago. The road accidents also in an upward trend due to the

increment of the cars. Basically, the road accident has reached a significant

number that really needs the concern of the country [1]. The traffic accidents

that involve pedestrians commonly occur all around the world every year.

Many pedestrians have been hurt or killed in the accidents. According to the

statistics of The Pedestrian and Bicycle Information Centre (PBIC), there are

4280 pedestrian deaths and 70000 pedestrian injuries in United States in year

2010 [2]. Pedestrians are vulnerable and easily get hurt by clumsy car drivers.

Sizes of pedestrians are relatively small compare to the vehicles and thus they

are always neglected from the drivers’ sight.

Therefore, there comes the development of driving aid systems with

mapping. The main function of the driving aid system is to detect the

obstacles that potentially bring harm to the vehicle and driver. Mapping

system can be displayed on a graphical user interface, hence to assist the

driver to obtain the surrounding information of the vehicle. There are mapping

system with different sensors such as piezoelectric sensor, infrared sensor,

microwave radar, ultrasonic sensor and laser scanner in the market [3-8]. But

majority of the sensing technology nowadays still focus on the detection of

vehicle.

Ultrasonic sensors are also known as transceivers when they both send and

receive. Basically the working principles of ultrasonic are similar to radar or

sonar. They evaluate attributes of a target by interpreting the echoes from

radio or sound waves respectively. However, ultrasonic sensors generate high

frequency sound waves and evaluate the echo which is received back by the

sensor. Sensors calculate the time interval between sending the signal and

receiving the echo to determine the distance to an object. For automobile, its

function is to emit and alarm by sound and display when approaching the

obstacles. In this project, we try to further develop an ultrasonic driving aid

system which able to detect pedestrians and obstacles that potentially harmful

threaten the vehicles and drivers.

II. METHODOLOGY

A. The Basic Principle

As shown in Figure 1, a sensor is used to send the signal and to receive the signal from the obstacle. Based on the reflected signal, the distance of the

obstacle is calculated. The mechanism of ultrasonic sensor is to achieve the

highest angle coverage for the sensor to detect the obstacle in the surroundings. By using multi-platform supported programming software, Java

programming language, the data is acquired from the PIC and map the vehicle

surrounding and it is displayed in a graphics so that it can be displayed on the screen for the driver to notice on the obstacles on the road. The dot displayed

on the screen represents the obstacles detected. By referring to the screen, the

driver will be able to react accordingly.

Fig.1. Block diagram of the basic principle

B. Tools Selection

(I) Java Programming

Java Programming Language was selected as the platform to develop an intuitive Graphical User Interface. Java is generally an object-oriented

programming software which involves creating and manipulating objects, and

making objects work together. Modular programs and reusable code is able to be generated through the usage of this platform. The powerful highlight of

Java is that it is platform independent or in the other words it is multi-

platform. In addition, we aim to make this Java program to be android compatible so that it is portable and provide greater mobility. Therefore, the

users can use it via their smart phones or android tablet.

(II) Ultrasonic Sensor

Ultrasonic sensor offers two functions which are sending signal and

receiving signal. Its main advantage is to calculate the distance to an object or obstacle by calculating the time interval between sending the signal and

receiving the echo. Ultrasonic sensor model HC-SR04 is used for the system

as shown in Figure 2. Sensing area or the coverage of a sensor is the first concern when choosing sensor. Since ultrasonic wave is emitted in a cone

shape with certain effectual angle, it provides larger detecting area if

compared to IR distance sensor which sensing area is only on a point or a straight line. This sensor detects object of maximum 5 meter away. This range

is not enough for detect car from distance. The idea sensing distance would be

10 to 15 meter and needed to be increase when vehicle’s speed increases. Besides, the maximum sensing rate of this sensor is 20Hz and it is not fast

enough to capture distance since it need to rotates for 180° in certain time.


278

Fig. 2. Ultrasonic sensor model HC-SR04

(III) PIC Microcontroller

PIC from MicroChip® is comparatively cheaper choice to implement in our project. It is considered cheap if compared to other same level product

from different brand such as NXP, ATLET, TEXAS, CYAN and so on. The

reason 33 series products being chosen among wide range of MicroChip® product is this series of PIC provides more peripherals that meet this research

project requirement. 4 input captures channel available in this PIC allows the

increases of sensor used in this project. If 16 series product being used, only 2 sensors are allowed to implement in this project which is not enough if this

system applied to a large vehicle. In addition, this PIC has plastic dual in line

package (PDIP) which makes the soldering of it PCB easier compared to surface mount device (SMD).

(IV) The Mechanism of Ultrasonic Sensor, Servo Motor and its Casing In order to achieve accurate angle measurement, servo motor is introduced

since it is a closed loop system device which accurately maintains its shaft

angle according to the input given. Therefore, no external sensor is needed to measure the angle or heading of the rotation. The casing for the servo and

ultrasonic sensor is also crucial for this system. It acts as a protective layer of

the servo and ultrasonic sensor. Since the ultrasonic sensor is mounted on the servo motor, it is moving within 180° to detect the surrounding obstacles.

Figure 3a shows the upper part of the casing, which allows the ultrasonic sensor to move within 180°. Figure 3b represents the whole casing design.

Cylindrical shape of casing is the most suitable choice so that the sensor can

move less rigidly and provide better flexibility for mechanism.

Fig.3a. Upper part of the casing - Servo and ultrasonic sensor

Fig.3b. The whole casing

C. The Conceptual Design

In overall, the ultrasonic sensor is fixed on the servo motor to moving

within 180°. The developed Java program is responsible in acquiring the data from the PIC which is the distance and angle of the obstacle. After acquiring

the distance and angle of the obstacle, user interface will be generated and it

gives a graphical representation to the driver to determine the location of the obstacle in terms of its distance and angle. In terms of hardware mechanism,

the cylindrical casing is used to protect the servo motor and ultrasonic sensor.

The upper part of the casing is designed to be movable to allow the sensor to move within 180° whereas the lower part is mounted on the car surface

temporarily by using permanent magnet.

III. RESULTS AND DISCUSSION

A. Vehicle Surrounding Supervision Hardware

(I)Ultrasonic Sensor

HC-SR04 is an Ultrasonic ranging module which provides 2cm -500cm

non-contact measurement function and having resolution up to 3mm.

Ultrasonic waves are emitted in forming a cone which shape propagate through air. The best effectual angle is recommended in less than 15°. It is

operate in DC 5V and consume current less the 2mA. The modules includes

ultrasonic transmitters, receiver and control circuit and there are 4 pins soldered for external connection, which are Vcc, Trigger, Echo and ground.

Each of the pin has their function and the working principles are (as shown in Figure 4):

I. Using IO trigger for at least 10us high level signal. II. The Module automatically sends eight 40 kHz and detect whether

there is a pulse signal back.

III. If the signal back, through high level, time of high output IO duration is the time from sending ultrasonic to returning.

Fig. 4. Timing diagram

The cycle time for trigger used in this project is 50mS. In other word, this ultrasonic sensor will be trigged every 50mS and provides distance data at

20Hz. The measured distance can be simply calculated by using speed

equation where ultrasonic travel at speed of sound, 340m/s. The time took to receive echo need to divide by 2 in distance calculation since the waves travel

front and back to the sensor module. Test distance = (high level time / 2) ×

velocity of sound Test distance (cm) = pulse width (uS) / 58. Table 1 shows

some test results.


279

Table 1: Table of test results

(II) Servo Motor

HD-1160A (as shown in Figure 5) is a micro size servo which having

torque of 2.7/6V kg/cm, which is sufficient for sensor mounting. These servos are supplied 5V in this project and moving no load except a ~50g ultrasonic

sensor while servo itself weighted 25g. Pulse Width Modulation (PWM) is

used to control the servo motor. The servo motor shaft rotation changes according to the high level time of the PWM, which called duty cycle. For the

position at neutral position or 90°, the high level time must be 1.5 ms. Hence,

the period of the PWM is set to 3mS so that the neutral position have 50% duty cycle. Decreases the duty cycle can changes the servo position toward 0°

while increase the duty cycle can changes toward 180°.

Fig. 5. HD-1160A Servo [11]

Since different servo have different characteristic, the servos in this research

project are pulsed from 0.5mS (15%) to 2.5mS (85%) and from 2.5mS to

0.5mS. This enables those servo motors to rotate 180° forward and backward repeatedly (as shown in Figure 6).

Fig. 6. Servo PWM control [12]

(III) Microcontroller The microcontroller used in this research project is PIC33128MC802 from

MicroChip Inc. as shown in Figure 7. It is a 33 series 16 bits microcontroller

operates in 3.3v. It is 28 pins plastic dual inline package (PDIP) and equipped with various peripheral such as PWM, UART, timer, SPI, I2C, input capture,

QEI and so on. A timer is used to periodically pulse the trigger pin of

ultrasonic sensor at 20Hz. While another timer used to periodically initiate UART send command for data communication purpose. Besides, 4 Input

captures ports are used to measure the high level time of the ultrasonic sensor

echo feedback. Two general IO ports used to control buzzer and servo calibration. PWM also produced by MCU for the servo control.

Fig. 7. PIC33FJ128MC802

(IV) UART Interface The UART interface device can be either wired or wireless (as shown in

Figure 8). UC00B Cytron USB-UART interface can be applied as wired device. It connects between UART molex pins on PCB and PC USB port.

While JY-MCU is a Bluetooth module that can be use as wireless channel.

Fig. 8. UC00B from Cytron and JY-MCU from JY

(V) Circuit and Board Design


280

EAGLE or Easily Applicable Graphical Layout Editor is free license software by Cadsoft which capable for schematic capture, PCB layout, auto-

router and CAM program. It has been use in this project on schematic drawing

and printed circuit board routing. The produced PCB sized 72mm x 73mm. It is a single layer board and required 2 jumper wires connection as shown in

Figure 9.

Fig. 9. PCB layout

B. Hardware Programming

(I) MPLAB MPLAB integrated development environment is a freeware distributed

from MicroChip®. Embedded applications which employing Microchip's

product (PIC® and dsPIC® microcontrollers) can use it as an integrated toolset for fast application development and super-charged debugging.

MPLAB V8.8 had been used in this project for dsPIC33 microcontroller C

language programming and hardware debugging. PIC-kit 2 is a programmer

design to program PIC microcontroller family. It uses PC’s USB to transfer

program compile by MPLAB to PIC flash by performing on board in circuit

serial programming (ICSP).

Fig. 10. PIC Kit 2

(II) Initialization

Initialization can be separated into 2, MCU and peripheral. MCU initialization includes CPU clock setting and pins multiplexing. In

MCU_Init() function, CPU clock has been setting to 39.32MHz by internal

FRC with PLL. Peripheral_Init() is a function used to assign peripheral to specific pins and disable peripheral which not in use.

(III) Timers There are 3 timers used in the program. Timer 1 has period of 50mS, used

to pulse to sensor’s trigger pin at 20Hz. Timer 3 has same period as timer 1,

50mS, used as the input capture referred timer. Input capture module will

capture timer 3 value when an event occurs. Timer 2 has shorter period, 12.8mS, used to initiate UART send functions at 78Hz.

(IV) PWM PWM signal generates by PIC output to servo motors to control the

heading of sensor which mounted on the servo motor’s shaft. Since the high

time required by servo motor to be at 90° is 1.5mS, the PWM frequency had set to 333Hz or period of 3ms so that when servo motor is 90°, the PWM duty

cycle is 50%. The duty cycle had set to 50% when initialization, all servo

motors are pulsed to turn to 90° position and stay. If the switch 2 is toggled, program now entered servo calibration mode. This allows user to perform

sensor-servo position calibration, which adjustment may took place on sensor

orientation and heading refer to the latest 90°. It aims to reduce offset and zero error of the angle calculation.

After the calibration, servo motors are pulsed to turn to 180° and back to 0°

and repeat. In other word, the sensor mounted on the servo will rotates or changes its heading 180° frontward and backward with certain angular

velocity. The maximum angular velocity the servo motor can have is

depending on the update rate of the sensor and the UART transfer rate.

Ultrasonic Sensor update rate = 20Hz

Time of 1 measurement = 1/ 20 = 0.05s

Servo motor angle resolution = 2°

Time of 180° measurement

Angular velocity of servo

(V) Input Capture

This peripheral used to measure the respond of the ultrasonic sensor

through echo pin. First, it needs to detect a raising edge and capture the time3 value. Then, detect a falling edge, capture timer3 value and the high time is

the deviation between these 2 captures. Then Input captures are programmed

to detect a falling edge only at initialization stage. After a falling edge detected, it changes to detect every edges, raising and falling. These detection

changing steps is useful in eliminating the possibility to detect low time

instead of high time. In other word, if the input capture is programmed to

detect every edge at initialization stage, it has 50% possible to 35 detect low

time because the echo sequence can’t be ensured. After a falling edge been

detected, the high time value will be updated accordingly.

(VI) Universal Asynchronous Receiver Transmitter

UART had applied in this project as the communication channel between PIC and PC. A consensus UART setting has applied on both end of the

channel. The UART module works with 9600 Hz baud rate, 8 bits data, 1 stop

bit, and no parity bit. The PC GUI update rate is depend on the UART transfer rate and can be calculated by the following formula:

Total bit sent = 1start bit + 8 data bits + 1 stop bit = 10 bits

Time of each send

Timer2 interrupt routine will initiate UART sending functions. 9 bytes are

queued to UART send function every timer2 interrupt. They are start byte, sensors heading angle and sensed distance. Sensors heading angle are taken

from PWM1 duty cycle value, while sensors sensed distance are taken from input capture result.

The minimum timer2 period can’t be less than 18.72m because transmit

request speed is faster than UART transmission speed and it will cause PIC program halt half way. However, this UART transmission speed needed to be

further reduces due to the speed of PC and Java Program serial data process

capability. In order to increase the efficiency of data communication, every bit in a byte sent must be useful. Instead of representing 30010 as 0000 0010

0101 11002 (30010), the program first divides the value to be sent by 2,

30010 as 1001 01102 (15010). Scaling down the value can effectively reduces the data byte to be sent and increase the communication efficiency by reduces

meaningless bit to be sent (few MSB of 2 bytes data). The maximum value 8

bits data can represent is 256, so sensor heading (0 to 360) needed to be divide


281

by 2 so that it maximum (180) don’t exist 256. While the maximum distance sensed output is 655 and it needed to be divide by 3 so that its maximum

(218) don’t exits the 8 bits data range limit

Fig. 11. Data set

Number of bytes to be send = 9 Time of each send = 2.08ms

Total time = 9 x 2.08m = 18.72ms

However, this scaling does brings disadvantage. The resolutions of the data

are further reduce by the factor of scaling. 1° and 1cm are the original sensor heading and sensed distance resolution; they become 2° and 3cm after the

scaling. Docklight had been used to monitor the data sent from PIC in this

project as shown in Figure 12. It is a testing, analysis and simulation tool for serial communication protocols, such as RS232, RS485 and so on. It allows

user to monitor the communication between two serial devices by displaying

data receives from serial ports and sending data to another device pair with the serial communication channel.

Fig. 12. Docklight interface and received data from PIC

(VII) PIC Program Flow The main() program as shown Figure 13 is very simple. It first initializes

the MCU clock and all other peripheral, and then waits for the servo motor

calibration to complete. After that, it run the servo motor by gradually increase and decrease the PWM duty cycle.

Fig. 13. Main() program flow chat

The interrupt routine run when a rising or falling edge event occurs at input capture assigned pins (as shown Figure 14). If it is the first interrupt, indicates

a falling edge detected and then change input capture module to capture every

edge. UP is 0 when next interrupt occurs, indicates a raising edge detected, time_a save the time3 value. When the next interrupt occurred, UP is 1 and

indicates a falling edge detected, time_b save the timer3 value. If the time_b

smaller than time_a, an overflow of timer3 had took place, a time3 period needed to be add to time_b before high period can be calculated.


282

Fig.14. Input capture interrupt routine

C. JAVA Graphical User Interface

In the development of a Java program the IDE chosen for this application is Eclipse as it has got a greater number of info available in the internet

regarding Java-Serial Interface. The first approach in developing software that

can process the data provided by hardware, dummy software is coded to test and develop the processing part of this. This dummy software has got an

interface as shown in Figure 15.

Fig. 15. Interface of dummy software

The dummy software has got no serial data acquisition capability at all and

only takes in data key in by the user but this is the first approach in designing the data processing and it works. The processing of this software is mainly

based on Pythagorean Theorem. The code below processes the Angle and

Range of the obstacle which resembles the angle and hypotenuse of a right angle triangle. Sine all the location of the sensor in the screen is predefined in

the software the right angle calculation is relative to the location of the sensor.

privateintsensor1x = 377+5;

privateintsensor2x = 377+5;

privateintsensor3x = 323+4; privateintsensor4x = 323+4;

privateintsensor1y = 306;

privateintsensor2y = 394; privateintsensor4y = 306;

privateintsensor3y = 394;

Fig. 16. Sample diagram with angle 120 degree

The above sample diagram shows that when the sensor is selected as 2 and

the Angle is 120 while the range is 50 so the calculated distance is 43 and 24.

The background calculation is as shown below:

Distance x = tan(angle)*range

Distance y = cos(angle)*range

Therefore there is actually no theoretical limitation of numbers of sensors to

be placed at the vehicle and there is only a different of resolution of the image mapped. But most of the time the sensors used is normally around 4 but in this

prototype only 2 is used. The sensor can be placed as shown Figure 17.

Configuration with 4 sensors:

Configuration with 3 sensors:

Configuration with 2 sensors: Configuration with 1 sensor:


283

Fig. 17. Different sensor configurations

Since java only process radian in its math function there for the data

collected from hardware which is in degree form has to be converted into radian format before processing. As shown below is the conversion code.

doubleangle_radian; angle_radian = Math.toRadians(degree);

After conversion, many of the math function available in the Java library can be used. For example the sinfunction of distance_x = (int)

(Math.sin(angle_radian)*-range); can be used without importing other 3rd

party library. All the data gathered are being rendered with condition of its color. As the code below:

Fig. 18. Math functions in the Java library

The condition is set that when obstacle is near up to 1-feet only, the

indicator will show red while if the obstacle is 2 feet away, it will show yellow while the rest show Green indicator. The serial interface data

acquisition is based on a third party library name RTTX. As a matter of fact,

as stated previously, Java itself does not have a compatible library while JAVA Comm is the library but it does not support 64-bit system. Finally

RXTX library is chosen for the application. First the port is search through the

system and make sure that the port is available, and then it will initialize the port to make sure it is not in use. Thirdly, the port will be initially for listening

and lastly an event driven code is added to make the software respond to the

data input at Real Time. The output of the software is as shown in Figure 19:

Fig. 19. Output of the software

The above indication show that the obstacle is like a size of a lorry and is

quite near to the car itself. S can be seen, this will let user have a clear

understanding about what it is that is around the user. Figure 20 shows a

summary of test results in different situations.

Mapped Result

Actual Situation


284

Fig. 20. Summary of test results in different situations

D. Hardware Mechanism

Simple servo programming is needed for the hardware mechanism to react when the driver decides to switch off the system when it is raining or other

situation. Switch of the ultrasonic sensor controls the on/off states of

ultrasonic sensor is depending on the driver if the sensor needs to be used. Figure 21a and 21b below shows the configurations of the ultrasonic sensor

when it is switched on and switched off. When the sensor is switched on, the

sensor will be face outward to detect if there is any barrier or obstacle. On the other hand, when it is switched off, it will appear to be inactive and it does not

send out the signal nor receiving the signal. Figure 22 shows a working

prototype of the system.

Fig. 21a. On State

Fig. 21b. Off State

Fig. 22. A working prototype

IV. CONCLUSION

This project aims to reduce possible car accidents to map the

surrounding of the vehicles by using ultrasonic sensor. Literature review results show that the blind spot has always been a problem to

driver and one of the causes of car accident. Blind spot is sometimes

an issue that the driver could not really see the surrounding obstacles. Besides, drivers tend to be unable to see the surrounding in every


285

corner of the car. So, by mapping of surrounding obstacles, the driver can have a clear understanding of the surrounding. Therefore, the objective has

been fully met throughout the project. The aim of project of ultrasonic sensor

to map the surrounding of the vehicles has been achieved. When the surrounding obstacles have been sensed, the develop Java program will map

the surrounding obstacles and display on the screen.

Nevertheless, there are some limitations in this project which needs to be improved. In the project, the sensor is planned to have 180 degree of sensing

coverage. However, once the casing has been put on it, the sensing coverage

of the sensor has reduced which less than 180 degree. In addition, the sensing distance has been limited to only 5 meters away. Once the distance is far away

from 5 meters, the result will not accurate. In addition, due to the processing

speed of the Java programming is considered slow, so the update rate of output will be affected and might be lagging. The maximum of the sensors

that can be used are up to 4 pieces because the maximum input capture

channels of PIC are up to 4. Although Java Programming is compatible to most of the devices, there are some devices like some of the mobile phones or

non-smart-phone cannot be supported.

REFERENCES

[1] Mustafa, M. N. “Overview of current road safety situation in Malaysia”,

Road Safety Situation In Malaysia, 2006. [2] Pedestrian crash facts. (n.d.) NHTSA’s National Center for Statistics

and Analysis, 2012. [3] Qian & Han, “The Applications and Methods of Pedestrian Automated

Detection”, International Conference on Measuring Technology and

Mechatronics Automation (ICMTMA), 2010. [4] Carullo, A., & Marco, P. “An ultrasonic sensor for distance

measurement in automotive applications”, Sensors Journal, IEEE, vol. 1,

no. 2, 2001. [5] Kai-Tai, S., Chih-Hao, C., & Cheng-Hsien Chiu, H. “Design and

experimental study of an ultrasonic sensor system for lateral collision

avoidance at low speeds”, Intelligent Vehicles Symposium, IEEE, pp. 647-652, 2004.

[6] Fred, Y., Bozena, K., & Pawel, G. “A new driving assistant for

automobiles”. Canadian Conference on Electrical and Computer Engineering, 2007, pp. 1199-1202, 2007.

[7] Uvais, Q. “Fuzzy blind-spot scanner for automobiles”, IEEE

Symposium on Industrial Electronics & Applications, 2, pp. 758-763, 2009.

[8] Kukko, A., Jaakkola, A., Lehtomäki, M., & Kaartinen, H. “Mobile

mapping system and computing methods for modelling of road environment’, Urban Remote Sensing Event, 2009 Joint, pp. 1-6, 2009.

BIOGRAPHIES

Dr. Lee Jer-Vui is an Assistant Professor in the Department of Mechatronics and BioMedical

Engineering, Faculty of Engineering & Science, Tunku

Abdul Rahman University, Malaysia. His research interests are in the field of automation and robotics.

Chuah Yea-Dat is a lecturer in the Department of Mechatronics and BioMedical Engineering, Faculty of

Engineering & Science, Tunku Abdul Rahman

University, Malaysia. His research interests are in the field of mechatronics and biomedical engineering

system design.

Eric Tan Cheng Hoong is a final year student in the

Department of Mechatronics and BioMedical Engineering, Faculty of Engineering & Science, Tunku

Abdul Rahman University, Malaysia. His research

interest is in the field of mechatronics system design.

Lau Yee-Chuan is a final year student in the

Department of Mechatronics and BioMedical

Engineering, Faculty of Engineering & Science, Tunku Abdul Rahman University, Malaysia. His research


Puang En-Yen is a final year student in the




Tan Chor-Zheng is a final year student in the

Department of Mechatronics and BioMedical

Engineering, Faculty of Engineering & Science, Tunku Abdul Rahman University, Malaysia. His research


Teh Chun-Sien is a final year student in the




http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=5458391

http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=5458391

Vehicle Surrounding Supervision

Documents

Transcript of Vehicle Surrounding Supervision