ABSTRACT A vehicle tracking system combines the installation of
an electronic device in a vehicle, or fleet of vehicles, with
purpose-designed computer software to enable the owner or a third
party to track the vehicle's location, collecting data in the
process. Modern vehicle tracking systems commonly use Global
Positioning System (GPS) technology for locating the vehicle, but
other types of automatic vehicle location technology can also be
used. Vehicle information can be viewed on electronic maps via the
Internet or specialized software. In the main they are easy to
steal, and the average motorist has very little knowledge of what
it is all about. To avoid this kind of steal we are going to
implement a system it provides more security to the vehicle.
Existing System: In the previous system security lock and alarm is
implemented in a car. If a burglar can break open the lock, then it
becomes easy for the burglar to steal the car. And in old security
system if the car is stolen then it is out of the owner control.
User doesnt have any awareness about the current location of the
vehicle. The Proposed System: The RF transmitter is attached with
the vehicle which has its own identification. This data will be
continuously transmitted to the RF receiver connected to the
microcontroller. This GPS will be location the position of vehicle
and transmit that data to the microcontroller. Suppose the RF
receiver not receiving signal from the transmitting unit, receiver
unit send the signal to the microcontroller, from that we can
identify the theft. If the vehicle is theft it automatically sends
location of the vehicle to its owner as a SMS through GSM modem.
This will be a much simpler and low costtechnique compared to
others. If a password like SMS is sent by the owner, it
automatically stops the vehicle
This proposed work is an attempt to design a tracking unit that
uses the global positioning system to determine the precise
location of a object, person or other asset to which it is attached
and using GSM modem this information can be transmit to remote
user. It can provide tele-monitoring system for inter-cities
transportation vehicles such as taxis and buses. This system
contains single-board embedded system that is equipped with GPS and
GSM modems along with ARM processor that is installed in the
vehicle. During object motion, its location can be reported by SMS
message. A software package is developed to read, process, analyze
and store the incoming SMS messages. The use of GSM and GPS
technologies allows the system to track object and provides the
most up-to-date information about ongoing trips. If a password like
SMS is sent by the owner, it automatically stops the vehicle or we
can use it for different other work, it can provide real time
control. This system finds its application in real time traffic
surveillance. It could be used as a valuable tool for real time
traveler. The current system can be able to provide monitoring
process from anywhere. The purpose of this system is to design and
integrate anew system which is integrated with GPS- GSM to provide
following feature: a) Location information, b) Real time tracking
using SMS, c) track bus driver activity d) Communication is
instantaneous therefore we can receive running report quickly.
It is completely integrated so that once it is implemented in
all vehicles, then it is easy to track vehicles any time.Keywords:
Global Positioning System (GPS), RF receiver and transmitter,
operations and maintenance center (OMC) and Gaussian minimum shift
keying (GMSK)
I. INTRODUCTION
In the last few decades, India has progressed at such an
enormous rate that many companies have strongly established
themselves here. These companies bring a huge amount of workforce
with them. Arranging transportation to such a huge mass is a
cumbersome task in -volving many intricacies. Generally, this
transport is arranged through the local transport vend -ors on a
yearly contract basis, recently happen mishaps such as burglary,
rape cases etc. The development of satellite communication
technology is easy to identify the vehicle locations. Vehicle
tracking systems have brought this technology to the day-to-day
life of the common person. Today GPS used in cars, ambulances,
fleets and police vehicles are common sights on the roads of
developed countries. All the existing technology support tracking
the vehicle place and status . The GPS/GSM Based System is one of
the most important systems, which integrate both GSM and GPS
technologies. It is necessary due to the many of applications of
both GSM and GPS systems and the wide usage of them by millions of
people throughout the world . This system designed for users in
land construction and transport business, provides real-time
information such as location, speed and expected arrival time of
the user is moving vehicles in a concise and easy-to-read format.
This system may also useful for communication process among the two
points. Currently GPS vehicle tracking ensures their safety as
travelling. This vehicle tracking system found in clients vehicles
as a theft prevention and rescue device. Vehicle owner or Police
follow the signal emitted by the tracking system to locate a robbed
vehicle in parallel the stolen vehicle engine speed going to
decreased and pushed to off. After switch of the engine, motor
cannot restart without permission of password. This system
installed for the four wheelers, Vehicle tracking usually used in
navy operators for navy management functions, routing, send off, on
board information and security. The applications include monitoring
driving performance of a parent with a teen driver. Vehicle
tracking systems accepted in consumer vehicles as a theft
prevention and retrieval device. If the theft identified, the
system sends the SMS to the vehicle owner. After that vehicle owner
sends the SMS to the controller, issue the necessary signals to
stop the motor.
1.1 Objective:
Exploring GPS based tracking systems
Developing Automatic Vehicle Location system using GPS for
positioning information and GSM/GPRS or information transmission
with following features: Acquisition of vehicles location
information (latitude longitude) after specified time interval.
Transmission of vehicles location and other information (including
ignition status, door open/close status) to the monitoring
station/Tracking server after specified interval of time.
Developing a web based software to display all transmitted
information to end user along with displaying location of vehicle
on a map.The objective of the project is to build an additional
feature to the present security system that will warn the owner of
the vehicle by sending SMS when there has been an intrusion into
the vehicle. To provide a solution to avoid car stolen in the lower
cost than advance security car system. (GPS)For the purpose of
details of the block diagram refer fig
This vehicle tracking provides,the modules as Anti theft system
Position tracking Security such as while locking the cars,
confirmation whether the doors are open or closed.Overall system is
partitioned into two major design units.In-Vehicle unitTracking
Server / Monitoring Station.
1.2 Vehicle Tracking System:
A vehicle tracking system combines the installation of an
electronic device in a vehicle, or fleet of vehicles, with purpose
designed computer software at least at one operational base to
enable the owner or a third party to track the vehicle's location,
collecting data in the process from the field and deliver it to the
base of operation. Modern vehicle tracking systems commonly use GPS
or GLONASS technology for locating the vehicle, but other types of
automatic vehicle location technology can also be used. Vehicle
information can be viewed on electronic maps via the Internet or
specialized software. Vehicle tracking systems are also popular in
consumer vehicles as a theft prevention and retrieval device.
Police can simply follow the signal emitted by the tracking system
and locate the stolen vehicle. When used as a security system, a
Vehicle Tracking System may serve as either an addition to or
replacement for a traditional Car alarm. Some vehicle tracking
systems make it possible to control vehicle remotely, including
block doors or engine in case of emergency. The existence of
vehicle tracking device then can be used to reduce the insurance
cost.
1.3 GSM Overview:
Global System for Mobile Communications or GSM (originally from
Groupe Spcial Mobile), is the world's most popular standard for
mobile telephone systems. The GSM Association estimates that 80% of
the global mobile market uses the standard.[1] GSM is used by over
1.5 billion people[2] across more than 212 countries and
territories.[3] This ubiquity means that subscribers can use their
phones throughout the world, enabled by international roaming
arrangements between mobile network operators. GSM differs from its
predecessor technologies in that both signaling and speech channels
are digital, and thus GSM is considered a second generation (2G)
mobile phone system. The GSM standard has been an advantage to both
consumers, who may benefit from the ability to roam and switch
carriers without replacing phones, and also to network operators,
who can choose equipment from many GSM equipment vendors.
1.4 GPS Overview: The Global Positioning System (GPS) is a
space-based global navigation satellite system (GNSS) that provides
reliable location and time information in all weather and at all
times and anywhere on or near the Earth when and where there is an
unobstructed line of sight to four or more GPS satellites. It is
maintained by the United States government and is freely accessible
by anyone with a GPS receiver. The GPS project was started in 1973
to overcome the limitations of previous navigation systems,
integrating ideas from several predecessors, including a number of
classified engineering design studies from the 1960s. GPS was
created and realized by the U.S. Department of Defense (USDOD) and
was originally run with 24 satellites. It became fully operational
in 1994.
II. EVOLUTION OF GPS
The technology evolved from, Mr. Marconis transmission of radio
waves. This was applied for society during the 1920's by the
establishment of radio stations, for which you only needed a
receiver. The same applies for GPS- you only need a rather special
radio receiver. Significant advances in radio were bolstered by
large sums of money during and after the Second World War, and were
even more advanced by the need for communications with early
satellites and rockets, and general space exploration. The
technology to receive radio signals in a small hand-held, from
20,000kms away, is indeed amazing. Throughout the 1960s the U.S.
Navy and Air Force worked on a number of systems that would provide
navigation capability for a variety of applications In 1973
finally, the U.S. Department of Defense decided that the military
had to have a super precise form of worldwide positioning. And
fortunately they had the kind of money ($12 billion!) it took to
build something really good. In short, development of the GPS
satellite navigation system was begun in the 1970s by the US
Department of Defense. The basis for the new system was atomic
clocks carried on satellites, a concept successfully tested in an
earlier Navy program called TIMATION. The Air Force operated the
new system, which it called the Navstar Global Positioning System.
It has since come to be known simply as GPS. The first GPS
satellite was launched in 1978 and a second-generation set of
satellites ("Block II") was launched beginning in 1989. Today's GPS
constellation consists of at least 24 Block II satellites. A full
constellation of 24 satellites was achieved in 1994. GPS was
originally intended for military applications, but in the 1980s,
the government made the system available for civilian use. After
the downing of Korean Flight 007 in 1983 -a tragedy that might have
been prevented if its crew had access to better navigational tools-
President Ronald Reagan issued a directive that guaranteed that GPS
signals would be available at no charge to the world. That
directive helped open up a commercial market. Deployment of GPS
continued at a steady pace through the 1990s, with growing numbers
of civilian and military users. GPS burst into public awareness
during the Persian Gulf War in 1991. GPS was used extensively
during that conflict, so much so that not enough military-equipped
GPS receivers were available.
2.1 WHAT IS GPS? The Global Positioning System (GPS) is a
satellite-based navigation system made up of a network of 24
satellites placed into orbit by the U.S. Department of Defence that
continuously transmit coded information, which makes it possible to
precisely identify locations on earth by measuring the distance
from the satellites. The satellites transmit very low power
specially coded radio signals that can be processed in a GPS
receiver, enabling the receiver to compute position, velocity and
time thus allowing anyone one with a GPS receiver to determine
their location on earth. Four GPS satellite signals are used to
compute positions in three dimensions and the time offset in the
receiver clock. The system was designed so that receivers did not
require atomic clocks, and so could be made small and
inexpensively. The GPS system consists of three pieces. There are
the satellites that transmit the position information, there are
the ground stations that are used to control the satellites and
update the information, and finally there is the receiver that you
purchased. It is the receiver that collects data from the
satellites and computes its location anywhere in the world based on
information it gets from the satellites. There is a popular
misconception that a gps receiver somehow sends information to the
satellites but this is not true, it only receives data.
III. TRACKING OF THE SYSTEM3.1 GPS TRACKING GPS tracking unit is
a device that uses the Global Positioning System to determine the
precise location of a vehicle, person, or other asset to which it
is attached and to record the position of the asset at regular
intervals. The recorded location data can be stored within the
tracking unit, or it may be transmitted to a central location data
base, or internet-connected computer, using a cellular (GPRS, SMS),
radio, or satellite modem embedded in the unit. This allows the
asset's location to be displayed against a map backdrop either in
real time or when analyzing the track later, using customized
software.It is a fitted on the vehicle (car, bus, truck).The whole
controlling of the device is done by the mobile phone which provide
wireless connection between the VTS device and the user. The VTS
device has a sim slot in which a GSM SIM is fitted to receive and
transmit SMS. The user can sending a SMS through its mobile phone,
know the position of its vehicle and the system also provide the
facility to protect the vehicle. So for the understanding the whole
operation of VTS device, we can divide the whole working in the two
part1.Tracking the location of vehicle2. To provide protection of
vehicleThe VTS consist of GPS receiver which provide real time
location of vehicle. This real time datais store in MMC after a set
time interval by the MCU. GSM module directly connected to the MCU
which is use to send and receive the SMS. GSM module take the data
from the MMC and send this data to the user mobile phone. This data
consist of longitude, latitude, altitude, speed over ground, course
over ground, real time and date. By using Google maps we can find
the exact location of vehicle.The VTS also has another special
feature which provides not only the location of vehicle but also
protection of vehicle. To know the location of vehicle, it is
important to stop the vehicle as soon as possible. For the recovery
of vehicle, we are using to relays in the circuit in which one are
connected to the buzzer and other is connected to the power supply
of the engine of vehicle. User can simply by sending a SMS from
mobile, disable the engine of vehicle and we can recover the
vehicle very soon.
3.2 BLOCK DIAGRAM OF VEHICLE TRACKING SYSTEM
CIRCUIT DIAGRAM
3.3 Working Of Vehicle Tracking System In this Project it is
proposed to design an embedded system which is used for tracking
and positioning of any vehicle by using Global Positioning System
(GPS) and Global system for mobile communication (GSM).In this
project PIC series microcontroller is used for interfacing to
various hardware peripherals. The current design is an embedded
application, which will continuously monitor a moving Vehicle and
report the status of the Vehicle on demand. For doing so an PIC
series18F452 microcontroller is interfaced serially to a GSM Modem
and GPS Receiver. A GSM modem is used to send the position
(Latitude and Longitude) of the vehicle from a remote place. The
GPS modem will continuously give the data i.e. the latitude and
longitude indicating the position of the vehicle. The GPS modem
gives many parameters as the output. The same data is sent to the
mobile at the other end from where the position of the vehicle is
demanded. An EEPROM is used to store the mobile number. When the
request by user is sent to the number at the modem, the system
automatically sends a return reply to that mobile indicating the
position of the vehicle in terms of latitude and longitude.The
project is vehicle positioning and navigation system we can locate
the vehicle around the globe with micro controller, GPS receiver,
GSM modem, EEPROM. Microcontroller used is PIC18F452. The code is
written in the internal memory of Microcontroller i.e. ROM. With
help of instruction set it processes the instructions and it acts
as interface between GSM and GPS with help of serial communication
of microcontroller. GPS always transmits the data and GSM transmits
and receive the data. GPS pin TX is connected to microcontroller
via connector. GSM pins TX and RX are connected to microcontroller
serial ports.Microcontroller communicates with the help of serial
communication. First it takes the data from the GPS receiver and
then sends the information to the owner in the form of SMS with
help of GSM modem.GPS receiver works on 9600 baud rate is used to
receive the data from space Segment (from Satellites), the GPS
values of different Satellites are sent to microcontroller 18F452,
where these are processed and forwarded to GSM. From these values
microcontroller takes only latitude and longitude values excluding
time, altitude, name of the satellite, authentication etc. E.g.
LAT: 1728:2470 LOG: 7843.3089 GSM modem with a baud rate 57600 .GSM
is a Global system for mobile communication in this project it acts
as a SMS Receiver and SMS sender. EEPROM is an Electrically
Erasable read only memory which stores is used to store the mobile
number. The power is supplied to components like GSM, GPS and Micro
control circuitry using a 12V/3.2A battery .GSM requires 12v,GPS
and microcontroller requires 5v .with the help of regulators we
regulate the power between three components. As shown in circuit
diagram the microcontroller is the key part of VTS, Crystal
oscillator is used in the circuit to initiate the microcontroller
with the frequency of 10Mhz.A microcontroller use for providing
proper interfacing between the GPS & GSM module. A common
voltage of 4 voltage is given to all component of the circuit. Here
AC to DC converter circuit is used which comprises of an IC-LN2576.
It changes 12V DC supply to 4 V. Circuit diagram uses many
LEDs(Light Emitting Diode) for indication purpose. When we switch
on of our circuit network LED blink fastly for searching network.
When it get network its blinking time period increases. After
network is found , Now gsm module LED start blinking to search
,after that gps module LED start blinking, after that mmc LED start
blinking i.e. data started to being logged in the mmc card ,after
that sms LED start blinking and the circuit send message to the
registeres mobile number which send latitude and longitude to the
registered mobile number. Now as shown in the circuit some relays
are used, there are two relays used in the circuit that works on
+12v. It can support up to 50watt i.e. we can attached a device to
it which can work safely within 50watt. On relay two LED are placed
which is used to show the status of the relay ,i.e. when relay LED
is glowing then relay is in working position , If LED is not
glowing then relay is not working i.e. device attached to the
device will not work. Now according to the circuit diagram
microcontroller pin number 4 is used to initiate GSM module to pin
number 12 There are certain command which are used by the
subscriber for receiving the location of position and for changing
the setting. The EEPROM is used to store the commands sends by a
subscriber. Commons sends by mobile are received by GPS. These data
are reached to the EEPROM by the help of microcontroller. At the
time of changing the commands the old data are erased and new one
save. As shown in fig. microcontroller pin no.5 ic connected to the
GSM module serially, to the power key of the GSM module. And
microcontroller is connected to GPS module by pin no.7. Register is
used in this circuit for voltage drop and capcitor is used for
blocking of AC current..When GSM is initiate it firstly check the
status of the module, now after that GSM transmitter ,receiver
serially interfaced with microcontroller transmitter ,receiver. In
GSM DCE is used as a client and DTE is used as a terminal, DCE-DTE
are connected to the following signal.There are two ports used,1.
Serial port 12. Serial port 2GSM and GPS module is used here can be
switched off due to the insufficient supply of voltages so for that
in GPS V-BAT pin is used,and in GSM BACK_UP key is used. The four
pins of microcontroller RB5,RB4,RB7,RA0,RA1, represent four LED
which glows during the working of the circuit. The first LED
represents MMC LED if it is glowing data is stored in MMC card.
second LED represent GPS data .If it is blinking fastly then GPS
module searching for its service, third LED represent SMS SEND LED.
Its blinking shows SMS is sent by GSM module to the registered
mobile number and GPRS SEND LED blinking represents that GSM module
is searching for its service provider. With GSM module SIM is
interface with pin number 6,7,8,9.With pin number 9 VSIM which
means power is supplied to the SIM card.GSM module pins
SIM_RESET,SIM_CLOCK,SIM_DATA is interfaced with same SIM pins and
one pin of the SIM is ground. Resistors are used between GSM module
and SIM to block the excess current.With microcontroller MMC card
is also interfaced. Pin number 44,43 represents data in and dataout
pin which serially interfaced MMC data out and data in pins. MMC
data out pin with also connected with EEPROM which is used to store
commands. The difference between MMC card and EEPROM is that in MMC
card latitude ,longitude which is sent by GSM module is stored
while in EEPROM commands are saved.
RESULT
3.4 GSM AND GPS BASED VECHICLE LOCATION AND TRACKING SYSTEM
DescriptionPresent project is designed using 8051
microcontroller in this Project it is proposed to design an
embedded system which is used for tracking and positioning of any
vehicle by using Global Positioning System (GPS) and Global system
for mobile communication (GSM). In this project AT89S52
microcontroller is used for interfacing to various hardware
peripherals. The current design is an embedded application, which
will continuously monitor a moving Vehicle and report the status of
the Vehicle on demand. For doing so an AT89S52 microcontroller is
interfaced serially to a GSM Modem and GPS Receiver. A GSM modem is
used to send the position (Latitude and Longitude) of the vehicle
from a remote place. The GPS modem will continuously give the data
i.e. the latitude and longitude indicating the position of the
vehicle. The GPS modem gives many parameters as the output, but
only the NMEA data coming out is read and displayed on to the LCD.
The same data is sent to the mobile at the other end from where the
position of the vehicle is demanded. An EEPROM is used to store the
mobile number. The hardware interfaces to microcontroller are LCD
display, GSM modem and GPS Receiver. The design uses RS-232
protocol for serial communication between the modems and the
microcontroller. A serial driver IC is used for converting TTL
voltage levels to RS-232 voltage levels .In the main they are easy
to steal, and the average motorist has very little knowledge of
what it is all about. To avoid this kind of steal we are going to
implement this project which provides more security to the vehicle.
When the request by user is sent to the number at the modem, the
system automatically sends a return reply to that mobile indicating
the position of the vehicle in terms of latitude and longitude from
this information we can track our vehicles.
3.5 APPLICATIONS AND ADVANTAGES
APPLICATIONS Stolen vehicle recovery . Field sevice management.
It is used for food delivery and car rental companies.
ADVANTAGES: It provides more security than other system. From
the remote place we can access the system. By this we can position
the vehicle in exact place.
IV. TECHNOLOGY
4.1 GPS Technology The Global Positioning System (GPS) is a
satellite-based navigation system consists of a network of 24
satellites located into orbit. The system provides essential
information to military, civil and commercial users around the
world and which is freely accessible to anyone with a GPS receiver.
GPS works in any weather circumstances at anywhere in the world.
Normally no subscription fees or system charges to utilize GPS. A
GPS receiver must be locked on to the signal of at least three
satellites to estimate 2D position (latitude and longitude) and
track movement. With four or more satellites in sight, the receiver
can determine the user's 3D position (latitude, longitude and
altitude). Once the vehicle position has been determined, the GPS
unit can determine other information like, speed, distance to
destination, time and other. GPS receiver is used for this research
work to detect the vehicle location and provide information to
responsible person through GSM technology.
GSM MODULE
4.2 GSM MODEM
The GSM modem is a specialized type of modem which accepts a SIM
card operates on a subscribers mobile number over a network, just
like a cellular phone. It is a cell phone without display. Modem
sim300 is a triband GSM/GPRS engine that works on EGSM900MHz,
DCS1800MHz and PCS1900MHz frequencies.GSM Modem is RS232-logic
level compatible, i.e., it takes-3v to -15v as logic high and +3v
to +15 as logic low.MAX232 is used to convert TTL into RS232 logic
level converter used between the microcontroller and the GSM board.
The signal at pin 11 of the microcontroller is sent to the GSM
modem through pin 11 of max232.this signal is received at pin2 (RX)
of the GSM modem. The GSM modem transmits the signal from pin3 (TX)
to the microcontroller through MAX232, which is received at pin 10
of IC1 [9].
Features of GSM Single supply voltage 3.2v-4.5v Typical power
consumption in SLEEP Mode: 2.5mA. SIM300 tri-band MT,MO,CB, text
and PDU mode, SMS storage: SIM card Supported SIM Card :1.8V,3V
GSM MODEM CIRCUIT DIAGRAM
4.3 THE GSM NETWORK:
GSM provides recommendations, not requirements. The GSM
specifications define the functions and interface requirements in
detail but do not address the hardware. The reason for this is to
limit the designers as little as possible but still to make it
possible for the operators to buy equipment from different
suppliers. The GSM network is divided into three major systems: the
switching system (SS), the base station system (BSS), and the
operation and support system (OSS).
Fig 3.GSM Network Elements
The operations and maintenance center (OMC) is connected to all
equipment in the switching system and to the BSC. The
implementation of OMC is called the operation and support system
(OSS). The OSS is the functional entity from which the network
operator monitors and controls the system. The purpose of OSS is to
offer the customer cost-effective support for centralized,
regional, and local operational and maintenance activities that are
required for a GSM network. An important function of OSS is to
provide a network overview and support the maintenance activities
of different operation and maintenance organizations
SPECIFICATIONS AND CHARACTERISTICS FOR GSM
The specifications and characteristics for GSM Frequency bandThe
frequency range specified for GSM is 1,850 to 1,990 MHz (mobile
station to base station). Duplex distanceThe duplex distance is 80
MHz. Duplex distance is the distance between the uplink and
downlink frequencies. A channel has two frequencies, 80 MHz apart.
Channel separationThe separation between adjacent carrier
frequencies. In GSM, this is 200 kHz. ModulationModulation is the
process of sending a signal by changing the characteristics of a
carrier frequency. This is done in GSM via Gaussian minimum shift
keying (GMSK). Transmission rateGSM is a digital system with an
over-the-air bit rate of 270 kbps.
4.4 Debugging and Testing Process A microcontroller-based system
is a complex activity that involves hardware and software
interfacing with the external world. Doing well design of a
microcontroller-based system requires skills to use the variety of
debugging and testing tools available. The debugging and testing of
microcontroller-based systems divided into two groups:
software-only tools and software-hardware tools. Software-only
tools come as monitors and simulators, which are independent of the
hardware under development. Software-hardware tools are usually
hardware dependent, more expensive and range from in-circuit
emulators and in-circuit simulators to in-circuit debuggers. In
general, the higher the level of integration with the target
hardware, the greater the benefit of a tool, resulting in a shorter
development time, but the greater the cost as well. The factors to
consider when choosing a debugging tool are cost, ease of use and
the features offered during the debugging process. A software
simulator is a computer program running on an independent hardware
and it simulates the CPU, the instruction set and the I/O of the
target microcontroller. Simulators offer the lowest-cost
development tools for microcontroller-based systems and most
companies offer their simulator programs free of charge. The user
program operated in a simulated environment where the user can
insert breakpoints within the code to stop the code and then
analyze the internal registers and memory, display and change the
values of program variables and so on. Incorrect logic or errors in
computations can analyze by stepping through the code in
simulation. Simulators run at speeds 100 to 1000 times slower than
the actual micro controller hardware and, thus, long time delays
should avoid when simulating a program. Micro controller-based
systems usually have interfaces to various external devices such as
motors, I/O ports, timers, A/D converters, displays, push buttons,
sensors and signal generators, which are usually difficult to
simulate. Some advanced simulators, such as the Proteus from
Labcenter Electronics allow the simulation of various peripheral
devices such as motors, LCDs, 7-segment displays and keyboards, and
users can create new peripheral devices. Inputs to the simulator
can come from files that may store complex digital I/O signals and
waveforms. Outputs can be as form of digital data or waveforms,
usually stored in a file, or displayed on a screen. Some simulators
accept only the assembly language of the target microcontroller.
Most of the microcontroller software has written a high-level
language such as C, Pascal or Basic, and it has become necessary to
simulate a program has written in a high-level language. The
software program has written in c or assembly language and compiled
using Keil software. After compiler operation, the hex code
generated and stored in the computer. The hex code of the program
should be loaded into the AT89C52 by using Top win Universal
programmer.
V. DESIGN OF IN-VEHICLE UNIT
In-Vehicle unit is designed using OEM module Telit GM862-GPS
GSM/GPRS modem and microcontroller PIC18F248 manufactured by
Microchip. Figure 1 shows the block diagram of In-Vehicle unit
Fig. 1 Vehicle Unit Block diagram.GPS antenna receives signals
from GPS satellites and it must face towards sky for correct
computation of the current location by GPS receiver. Location data
is transferred to microcontroller through serial interface. After
processing of the data provided by GPS receiver, microcontroller
transmits this information to remote location using GSM/GPRS modem.
Microcontroller controls the operation of GSM/GPRS modem through
serial interface using ATcommands. External GSM antenna is required
by the GSM/GPRS modem for reliable transmission and receiving of
data. When modem receives any command sent by tracking server, it
passes this information to microcontroller which analyses received
information and performs action accordingly (i.e. turns on/off
ignition of vehicle, transmits current location, restarts GPS
receiver, restarts whole system etc). Some of microcontroller I/O
ports are connected to vehicle ignition on/off circuitry and door
status output of vehicle. Information packet sent to server also
contains status information of these I/O ports.
5.1 GM862-GPS Interface Board DesignFirst step in circuit design
of In-Vehicle unit is to design interfacing circuit for Telit
GM862-GPS so that it can be interfaced with microcontroller. Telit
GM862-GPS is provided of the following interfaces: GSM Antenna
Connector Board to Board Interface Connector SIM Card Reader GPS
Antenna ConnectorGSM, GPS antennas and SIM card are not important
from design point of view as they can be just installed into
connectors. Only important is board to board interface connector
which provides interface for external devices to the modem.
5.2Vehicle UnitThis is major part of the system and it will be
installed into the vehicle. It is responsible for capturing the
following information for the vehicle Current location of vehicle
Speed of vehicle Door open/close status Ignition on/off
statusIn-vehicle unit is also responsible for transmitting this
information to Tracking Server located anywhere in the world. To
achieve all these functionalities In-Vehicle unit uses following
modules.GPS Receiver
In-Vehicle unit uses GPS receiver to capture the current
location and vehicle speed. Location and speed data provided by GPS
is not in human understandable format. This raw data needs to be
processed to convert it into useful information that can be
displayed by a beacon on the map. CPU is required to process this
raw data. SiRF Star III single-chip GPS receiver is used which
comes integrated with GM862- GPS which is GSM/GPRS modem used for
data transmission. GPS receiver can also provide information of
altitude, time of GPS fix, status of GPS fix, and number of
satellite used to compute current location information along with
location and speed. GPS fix means last reported location. For
tracking purpose only location and speed data is required for
transmission. Other data provided by GPS receiver is used to
determine the validity of location information.
5.3 Central Processing UnitThe raw data provided by the GPS
receiver is captured by the CPU and processed to extract the
required location and speed information CPU is also responsible for
monitoring the door/open close status of vehicle and controlling
the ignition on/off status of the vehicle. CPU holds all the
required information that is to be transmitted to remote server. It
also controls data transmission module to exchange information with
remote server. It actually acts as a bridge between GPS receiver,
vehicle and remote server. It receives commands sent by server
through data transmission/receiving module and performs
corresponding action required by server. As the processing required
in the In-vehicle unit is not computationally intensive therefore
any low end microcontroller can be used as a CPU. The
microcontroller selected to serve as CPU for In-vehicle unit is
Microchips PIC18F248. This is 8-bit microcontroller and runs at
speed of 20 MHz which is enough speed for the system.
5.4 Data TransceiverWhen all required information is extracted
and processed,it needs to be transmitted to a remote Tracking
Server which will be able to display this information to the end
user. For real time tracking of vehicle, reliable data transmission
to remote server is very important. Wireless network is required to
transmit vehicle information to remote server. Existing GSM network
is selected to transmit vehicle information to remote server
because of broad coverage of GSM network. It is also cost effective
rather than to deploy own network for transmission of vehicle
information. For data transmission over GSM network GSM modem is
required. GSM modem can send and receive data SMS text messages and
GPRS data over GSM network. GM862-GPS GSM/GPRS modem is selected to
transmit data over GSM network because of its features and
capabilities. GM862-GPS provides AT commands interface i.e. all
functions can be accessed by use of AT commands. AT commands can be
sent to it using serial interface. It has built in UART that
accepts the AT commands and modem performs the function as required
by AT command received
VI. VEHICLE UNIT SOFTWARE DESIGN
Microcontroller is acting as Central Processing Unit for In-
Vehicle unit. All operations of the In-Vehicle unit are to be
controlled by the microcontroller. Microcontroller needs
instructions to operate the whole system. These instructions are
provided to microcontroller by writing the software into
microcontrollers flash memory. It reads the software instruction by
instruction and performs the action as required by instruction.
Complete software is broken down into smallmodules as shown by the
Figure 2.
Fig. 2 Breakdown of In-Vehicle software
All these modules are implemented as subroutines in the
software. Each subroutine performs series of its designated tasks.
Flow chart of each subroutine is described below.
6.1 Subroutine- Send AT Command
This subroutine is the basic routine which handles all the
communication with GM82-GPS. This routine accepts the string
containing AT command input in its parameters and sends this string
character by character to module. GM862-GPS accepts carriage return
(\r) as a command terminating character. As this character is
received it sends back the response to microcontroller.
Figure 3 shows the flowchart
As shown in the flow chart routine checks each character of
string, if the character is not null, it will check the transmit
buffer contents. If transmit buffer is empty it will write new
character into the buffer. Transmit buffer is a hardware register
of UART. As soon as a 8-bit data is written into the transmit
buffer, UART hardware transmits that character at the specified
baud rate. Each character of command string will be sent in this
way. When null character is found, it specifies end of string and
routine terminates by sending carriage return to the module.
Response received from the module will be handled in another
subroutine.6.2 Subroutine- StartupStartup routine is executed only
when device is powered on. It initializes all hardware of the
In-Vehicle unit and configures GM862-GPS. It performs various tests
to ensure the GM862-GPS is working properly and is ready to use.
Figure 4 shows the flowchart.
Fig. 4 Flow chart of startup subroutine
As shown in the flowchart subroutine starts with initializing
peripherals of the microcontroller. All peripherals in use need to
be initialized in this step. After initializations All commands
sent to module are sent using this subroutine. If the device
responds with OK, it means microcontroller can communicate with
module. If device doesnt respond after expiration of timeout
routine is restarted. If problem persists definitely something in
hardware is damaged. After receiving OK response from module
various parameters of module need to be initialized. SIM presence
is checked by sending command AT+CPIN? If device responds with
+CPIN: READY message, SIM is ready to use. Any other response
message will be considered be sent over network. If any other
response is received module keeps on checking for network status
until it connects to network. Once it makes sure that module is
connected to network, subroutine is terminated.
6.3 Subroutine- Read GPS Data
GPS controller is by default powered on when module is switched
on. Figure 5 shows the flow chart for Read GPS Data subroutine. As
shown in the flow chart subroutine first of all checks whether GPS
controller is powered on? To check this AT$GPSP? is sent to the
module. If it responds with $GPSP: 0 it is not powered up. If it is
not already powered up; it can be switched on by sending AT$GPSP=1.
Once GPS controller is powered up location information can be read
from it by sending AT$GPSACP. The module responds with a long NMEA
sentence. The information of interest is latitude, longitude,
speed, number of satellites used in calculating latitude and
longitude. This information is extracted from the received response
and saved in formatted string. This string can be later on passed
to Send SMS subroutine to send it to remotely located Tracking
Server.
Fig. 5 Flow chart of subroutine Read GPS Data
6.4 Subroutine- Send SMS
This subroutine accepts message string as input parameter which
needs to be transmitted. Subroutine adds a terminating character
Ctrl-Z at the end of message string as shown in the Figure 6 Then
it checks whether module is in Text SMS mode. It can be checked by
sending command AT+CMGF? If module responds with +CMGF: 0 it is in
PDU mode. Mode can be changed to text by sending command AT+CMGF=1.
To send an SMS module requires destination phone number that is
sent to module using command AT+CMGS= da where da represents the
destination phone number. This phone number will be read from
microcontroller internal memory which is stored during programming.
After sending destination number module waits for prompt >. When
prompt appears message string is sent using Send AT Command
subroutine. If message sent successfully, module responds with
+CMGS: where mr is message reference number. If any error occurs
subroutine tries to resend the message until it is successfully
sent.
Fig. 6 Flow chart of subroutine Send SMS
6.5 Subroutine- SMS configuration
SMS configuration subroutine is call after startup routine. It
is basically called once after powering up the In-Vehicle unit like
startup routine. SMS Configuration It can be part of startup
routine but it is separated because it does configuration of the
module related to SMS only. Figure 7 shows the flow chart.This
subroutine checks the SMS service centre number by sending the
command AT+CSCA? Service centre number is required because SMS is
routed to destination via SMS service centre.The module responds
with +CSCA: number. If no number is present it can be saved in
module by sending the command AT+CSCA= number, type type could be
145 if number is in international number format (i.e. it begins
with +) or it could be 129 if number is in national format. When
new message is received by module an unsolicited indication is
generated. This indication may be sent to microcontroller, buffered
if microcontroller is busy or discarded. In this case new message
must be immediately sent to microcontroller or buffered if
microcontroller is busy. This configuration can be done by sending
command AT+CNMI=1, 1, 0, 0, 0 when GSM modem receives a new message
it will send +CMTI: SM, message index no where message index no is
location of message in memory and it can be then read by sending
command AT+CMGR=message index no. After configuring new message
behavior module is set to Text mode for SMS. It can be done by
sending command AT+CMGF=1. All configuration related to SMS is
finished and subroutine terminates. .Fig 7 Flow chart of SMS
configuration
6.6 Subroutine- Configure GPRS
. Fig. 8 Flow chart of subroutine configure GPRS
When GPRS service is available, it is cost effective and more
efficient to transmit vehicle information through GPRS. In order to
connect to GPRS, it needs to be configured. Figure 8 shows the
steps required to configure the GMS module for GPRS data
transmission. First step in configuration of GPRS is to define GPRS
context. It is set of information to identify the internet entry
point interface provided by the ISP. With these parameters the GPRS
network identifies the ISP to be used to gain access to the
internet and defines the value of IP address of the GPRS device
once connected. Fig. 8 Flow chart of subroutine configure GPRS The
command sent for defining GPRS context is AT+CGDCONT=1, IP,
payandgo.o2.co.uk, 0.0.0.0, 0, 0. First parameters is context id,
it is possible to define up to 5 contexts. Next parameter is
protocol used for communication, third parameter is APN assigned by
network server provider. In next step subroutine sets the
parameters for Quality of service. Commands used are AT+CGQMIN=
1,0,0,0,0,0 and AT+CGREQ=1,0,0,3,0,0. These parameters are
recommended by manufacturer of the GSM module. Along with APN
network service provider also provides user name and password to
connect to ISP. Next step is to set user name and password for
current GPRS context. Commands used are AT#USERID=payandgo and
AT#PASSW=password. Next step configures the TCP/IP stack. It
basically sets the minimum packet size, data sending timeout and
socket inactivity timeout. Command used for configuring TCP/IP
stack is AT#SCFG=1,1,140,30,300,100. First parameter of command is
connection identifier; next parameter is context identifier for
which stack is being configured. 300 is the minimum number of bytes
that will be sent in one packet. Next parameters are inactivity
timeout, connection timeout, and data sending timeout. Next step of
the subroutine is configures the firewall settings. It allows
certain computers to connect to module. In this case server IP
address will be provided to firewall so that Tracking server can
connect to In-Vehicle unit. Command used for firewall settings is
AT#FRWL=1,server ip, subnet mask. Server IP address will be the IP
address of Tracking server and subnet mask can be provided to allow
access to range of computers. Last step is activate current GPRS
context. Command is AT#SGACT=1, 1. First parameter is context id to
be activated and next parameter is status i.e. 1 for activation and
0 for deactivation.
6.7 Subroutine-Send Information Using GPRS
When In-Vehicle unit is configured to send information using
GPRS, all activities of In-Vehicle unit are controlled by this
subroutine. Fig. 9 Flow chart of subroutine Send Information using
GPRS Figure 9 shows the flowchart for this subroutine. In order to
send data over IP network application needs an interface to
physical layer. This interface is named as socket. This subroutine
starts with opening socket for currently configured TCP/IP stack.
Command used to open socket for configured embedded TCP/IP stack is
AT#SD=1, 1, 6534. First parameter is connection identifier of
TCP/IP stack, 2nd is protocol i.e. 0 for TCP and 1 for UDP. Next
two parameters are port number and IP address/host name of Tracking
server respectively. If command returns the response CONNECT;
connection is accepted. Data can be sent now. After getting
connection, socket is suspended using escape sequence +++ to bring
module in command mode. Socket remains connected while it is
suspended. When GPRS connection is alive, module cant accept AT
commands and GPS data cant be read from module. Once module is in
command mode this subroutine calls the routine Read GPS data which
provides the information string that is to be sent to Tracking
Server.
Fig. 9 Flow chart of subroutine Send Information using GPRS
Next step is to read I/O ports of microcontroller to get
vehicles door and ignition status. Information string received from
Read GPS data subroutine is appended with status of I/O ports.
Socket connection is resumed and information is sent to Tracking
server on this socket. If In-Vehicle unit is configured for
continuous transmission of vehicle information after regular
intervals, all above steps are repeated otherwise module waits for
incoming requests from Tracking server. If location request is
received above steps are repeated and if any other command is sent
by the server according action is taken. Server can send request
for vehicle shutdown, changing the data transmission from GPRS to
SMS or changing the continuous transmission to polling or vice
versa, restart the In-Vehicle unit. This subroutine ends only when
In-Vehicle unit is restarted by Tracking server.
6.8 Main Routine of In-Vehicle Unit
Main routine just calls the subroutines described in previous
sections. With start of main routine call is made to Startup
routine that initializes all peripheral and In-Vehicle unit
configurations. It checks for stored configuration to decide
whether data transmission should be through GPRS orSMS. If
configuration says for GPRS, call is made to GPRS configuration
routine and then GPRS data sending routine is run. If configuration
is for SMS, configuration is done and In-Vehicle unit starts
sending the vehicle information to Tracking server via SMS either
continuously after regular intervals or it waits for commands from
Tracking server as SMS. GM862-GPS is configured in such way that
whenever new SMS arrives, and indication is received by
microcontroller with message identifier. This message is read by
microcontroller and corresponding action is performed as shown in
Figure 10. All subroutines are implemented in C language. Compiler
used to generate machine language code for PIC18F248 is CCS
PICC.
Fig. 10 Flow chart of Main program
VII. TRACKING SERVER
Tracking server maintains all information received from all
In-Vehicle units installed in different vehicles into a central
database. This database is accessible from internet to authorized
users through a web interface. Authorized users can track their
vehicle and view all previous information stored in database.
Tracking server has a GSM/GPRS modem attached to it that receives
SMS from In-Vehicle units and sends those messages to the server
through serial port. Tracking server saves this information into
database.
Design of Tracking Server is partitioned into four major
parts.(i) Hardware design for GSM/GPRS Modem (GM862-GPS)(ii)
Communication Software for GM862-GPS(iii) Database(iv) Web
Interface
7.1 Web Interface Design As described in previous section
Tracking Server maintains all information in a database. To display
this information to end users front end software is required that
can display all information to the end user. End user is the user
of system who has installed the In-Vehicle unit in his vehicle and
also the administrator of the system who is managing Vehicle
Tracking System. There may be a number of vehicles installed with
In-Vehicle units therefore server must be able to manage and
distinguish information sent by all In-Vehicle units. For this
purpose information must be available to server about all vehicles
that are installed with In-Vehicle units.Whenever In-Vehicle unit
is installed, information about that vehicle is stored in the
database. Web interface must also support this functionality. Since
web interface will be accessible over the internet therefore access
must be restricted to authorized users only. Therefore information
about all users of the system must be stored in database.
7.2 Database Design Database is designed to store all received
vehicle information, information about In-Vehicle units and users
of the system. Information to be stored in the database is
Information about users of the system Information about vehicles
Information about received from vehicles 7.3 GM862-GPS Interface
Board for Tracking ServerGM862-GPS is GSM/GPRS modem that was used
in In-Vehicle unit. The same modem is used on server side to
exchange information with In-Vehicle units through SMS. Vehicle
information sent using SMS on GSM network is received by this
modem. Tracking server can also send commands for In-Vehicle units
using this modem. Same interface board is used on this side.
GM862-GPS interface board is connected to the serial (COM) port of
server. Server can communicate with modem using AT commands. To
send and receive data using this modem a software is required that
can send AT commands to module.
7.4 Design of Communication Software for GM862-GPSThe software
that is to be designed will provide communication interface to the
GM862-GPS modem attached to computers serial port. It will control
the operations of GM862-GPS. This software must be able to support
following functions Configuration of GM862-GPS for sending and
receiving SMS Receiving the SMS. Processing received SMS and saving
information into database Sending SMS to in vehicle unit as
required by user Accepting TCP/IP connections from In-Vehicle units
Exchanging information with In-Vehicle units through
internetGM862-GPS will be configured in such a way that whenever
new SMS arrives, GM862-GPS will send the information about SMS to
the serial port. Software will be listening at serial port; it will
read the SMS from GM862-GPS memory and extract the information from
SMS. After extracting the information SMS will be deleted from
GM862-GPS by software and information will be written to the
database. Design requirements suggest that following objects are
part of the system. GM862-GPS Modem Serial Port Vehicle Info TCP/IP
Socket DatabaseThis analysis yields following classes in the
system.
7.5 Data Flow
Fig. 11 Data flow of communication software
7.6 Software Flow
Figure 12 shows the flow chart of main program. Main program
listens for SMS and handles all communication with In-Vehicle units
using SMS. It creates a separate thread for listening to TCP/IP
connections, which receives incoming connections from In-Vehicle
units and creates separate thread for each incoming connection,
which allows any number of In-Vehicle units to connect to
server.
Fig. 12 Flowchart of communication software for GM862-GPS
VIII. SYSTEM TESTING AND RESULTS
System design needs to be verified by testing after integration
of all components of the system. PCB designed for In-Vehicle unit
and server side was assembled. After integrating all the
components, system was tested.
8.1 Testing In-Vehicle Unit (SMS Configuration)
GM862-GPS interface board was connected to microcontroller board
through a serial cable. Fig. 12 Flowchart of communication software
for GM862-GPS Debugging serial port of In-Vehicle unit was
connected to a laptops COM port to see the debugging messages
printed by microcontroller on HyperTerminal during its operation.
This laptop and debugging COM port is just for debugging purposes,
in real time there is no need to connect laptop to In- Vehicle
unit. After connecting the GSM antenna and GPS antenna to the
In-Vehicle unit system was powered on. Following logs of
microcontroller operation were captured from HyperTerminal
.Fig. 13 Results of execution of Startup routine
When In-Vehicle unit is powered on it executes Startup routine.
It first reads and displays the existing configuration of the
system. In next step microcontroller is configuring the GM862-GPS.
It first tests the communication interface by sending AT command.
GM862-GPS responded with OK message which shows that interface is
working. +CPIN: READY response shows that SIM card is ready and
+CREG: 0, 1 response shows that module is connected to network.
Fig. 14 Results of execution of SMS Configure routine
8.2 Testing Tracking ServerIn order to test server, laptop was
configured to act as a server. GM862-GPS COM was connected to COM
port of laptop. Apache server was run on laptop to make it act like
server. My SQL DBMS was installed. After running the Communication
software for GM862-GPS following results were observed.
Fig. 15 Logs of Tracking Server
8.3 Web Interface Testing
Since server is setup on the local machine. Website was opened
in internet explorer. After logging to the website it displayed the
page as shown in Figure.
Fig. 16 Pointing out current location of vehicle
CONCLUSION
The results presented in this paper contain execution of Startup
routine, execution of SMS Configure routine, Logs of Tracking
Server and Pointing out current location of vehicle. For vehicle
tracking in real time, in-vehicle unit and a tracking server is
used. The information is transmitted to Tracking server using
GSM/GPRS modem on GSM network by using SMS or using direct TCP/IP
connection with Tracking server through GPRS. Tracking server also
has GSM/GPRS modem that receives vehicle location information via
GSM network and stores this information in database. This
information is available to authorized users of the system via
website over the internet. Currently In-Vehicle unit was
implemented with two boards. Microcontroller board was externally
connected to GM862-GPS interface board. Single board can be
designed to incorporate Microcontroller circuitry on the GM862-GPS
interface board. It will reduce the overall size of In-Vehicle unit
and it will also reduce the number of components so will the
cost.
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GM862-GPS Hardware user guide. 1vv0300728 Rev. 8 - 20/09/07