SRAAC-GPS
Aniruddhasayali,siddhesh
24-03-2014

Smart Run-off Accident Avoidance Using
Co-ordinates from GPS
SRAAC-GPS

ANIRUDDHA SAYALI SIDDHESH

A thesis presented for the degree of
Doctor of Philosophy

Department of Electronics And Telecommunication
Engineering
Finolex Academy Of Management And Technology
Ratnagiri, Maharashtra
Date

ACKNOWLEDGEMENT
We hereby acknowledge those who have imparted their valuable time, energy, intellect and efforts for the timely completion of our project Smart Runoff
Accident Avoidance using Coordinates from GPS (SRAAC-GPS).
We express our sincere gratitude towards our guide Prof.S.R.Nalage , whose systematic and positive approach towards the progress of this project throughout the year has led to its successful and timely completion. We would like to thank him for his valuable suggestions and the efforts he has taken for the same.
We are also grateful to Prof.G.S.Kulkarni (Head of the Department,
Electronics and Telecommunication Engineering) for allowing us to use all the available facilities in the department necessary for the project.
We would also like to thank all the faculty members and staff for extending their helping hand whenever needed. We are indebted to laboratory supervisors Mr. Pardule and Mr. Biradar for their immense help in the project work.
Last but not the least, we are grateful to all our colleagues and friends for their constant support, constructive criticism and encouragement
1. Bavdhankar Aniruddha M.
2. Dabholkar Sayali S.
3. Kashalkar Siddhesh M.

ABSTRACT
India ranks no.1 in the whole world in case of occurrence of road accidents.
The main cause for such accidents is undisciplined driving, and roads with twists and turns. Blind turns have been responsible for many fatal roads accidents in recent years. Our project aims at providing an alert system for avoiding run-off road accidents using location coordinates from GPS.
Existing system and its limitations:
In our country, vehicles used by majority of the people are not equipped with special safety systems. GPS navigation is available only in high-end cars which are used only by a small section of the Indian society. Even though anti-braking and automatic braking is provided with costly cars, there is no provision made to indicate approaching blind turns or accident prone zones. Also, GPS navigation may provide the route to the driver, but it doesnt give hand on information about the crash prone regions or skid offs on the particular path.
Proposed system:
The project aims at providing a vehicle inbuilt-system for avoiding runoff-road accidents. It proposes to use the GPS system to indicate present location and generate automatic alerts of approaching accident prone area.
It will do so using software to compare database of predetermined location coordinates of accident-prone regions and assist in safe driving.

Contents
1 Introduction

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2 RELATED WORK

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3 OVERVIEW AND MOTIVATION OF WORK

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4 GPS TECHNOLOGY

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5 History and theory

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6 Global navigation systems
6.1 Operational GPS . . . . . . . . . . . . . . . . . . . . . . .

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7 SYSTEM DESIGN
7.1 BLOCK DIAGRAM .
7.2 DESCRIPTION . . .
7.3 CIRCUIT DIAGRAM
7.4 IMPLEMENTATION
7.4.1 HARDWARE .
7.4.2 SOFTWARE .

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8 GPS TECHNOLOGY
8.1 What is GPS? . . . . . . . . . . . . . . . . .
8.2 How it Works ? . . . . . . . . . . . . . . . .
8.3 Tracking Devices . . . . . . . . . . . . . . .
8.4 Navigation Systems . . . . . . . . . . . . . .
8.5 ADVANTAGES AND APPLICATIONS OF

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9 Nmea Format
9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . .
9.2 ELECTRICAL INTERFACE . . . . . . . . . . . . .
9.3 GENERAL SENTENCE FORMAT . . . . . . . . .
9.4 EXAMPLES OF NMEA SENTENCES . . . . . . .
9.4.1 BOD Bearing Waypoint to Waypoint: .

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GPS

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9.4.2

9.5

GGA Global Positioning System Fix Data. Time,
Position and fix related data for a GPS receiver
9.4.3 RMC Recommended Minimum Navigation Information . . . . . . . . . . . . . . . . . . . . . . . .
9.4.4 GSV Satellites in view . . . . . . . . . . . . . . . .
9.4.5 ZDA Time and Date UTC, Day, Month, Year and Local Time Zone . . . . . . . . . . . . . . . . .
9.4.6 GLL Geographic Position Latitude/Longitude
APPLICATIONS OF NMEA . . . . . . . . . . . . . . . . . .

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10 Project Advantages And Limitations
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10.1 ADVANTAGES . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.2 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 27
11 APPLICATIONS AND FUTURE SCOPE
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11.1 APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 28
11.2 FUTURE SCOPE . . . . . . . . . . . . . . . . . . . . . . . . 28
12 CONCLUSION

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13 APPENDIX A: GPS MODULE

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14 APPENDIX B: APR 9600 RE-RECORDING VOICE IC

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15 APPENDIX C: ATMEL 89C51 MICROCONTROLLER

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16 APPENDIX D: LM 386 AUDIO AMPLIFIER

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List of Figures
5.1

Accuracy of Navigation System . . . . . . . . . . . . . . . . .

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6.1
6.2

Global navigation systems . . . . . . . . . . . . . . . . . . . .
Launched GNSS satellites 1978 to 2012 . . . . . . . . . . . . .

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7.1
7.2
7.3
7.4
7.5

SRAAC-GPS BLOCK DIAGRAM . . . . . . .
Interfacing of Microcontroller with GPS module
APR 9600 Circuit Diagram . . . . . . . . . . .
PCB Layout-1 . . . . . . . . . . . . . . . . . .
PCb Layout-2 . . . . . . . . . . . . . . . . . . .

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13.1 EM 408-GPS Engine Board . . . . . . . . . . . . . . . . . . .
13.2 EM-408 Pin Assignment . . . . . . . . . . . . . . . . . . . . .

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14.1 APR 9600 Pin Configuration . . . . . . . . . . . . . . . . . .

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List of Tables
13.1 EM-408 Specification . . . . . . . . . . . . . . . . . . . . . . .

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Chapter 1

Introduction
In order to reduce the increasing number of road accidents due to misjudgment on turns (especially accident prone) and to save human lives, disciplined driving is essential. Since GPS is commonly used in vehicles now, it is easy to implement it to incorporate driving discipline and accident avoidance.
GPS module is now inbuilt in high-end cars for finding and indicating location of the vehicle and its vicinity to other vehicle. Our project uses software to create database and store predetermined accident prone locations to be compared with the real-time locations. The basic mechanism is comparison of actual GPS co-ordinates of the vehicle with those accident-prone locations stored in database which will be encountered during the journey route, and give audio-visual alerts to the driver automatically. The display unit shows all the details of the entire operation and also the visual alerts.

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Chapter 2

RELATED WORK
Audi
The full version of the system (Pre-Sense Plus) works in four phases. In the first phase, the system provides warning of an impending accident, while the hazard warning lights are activated, the side windows and sunroof are closed and the front seat belts are tensioned. In the second phase, the warning is followed by light braking, strong enough to win the driver’s attention. The third phase initiates autonomous partial braking at a rate of 3 m/s. The fourth phase decelerates the car at 5 m/s followed by automatic deceleration at full braking power, roughly half a second before projected impact. A second system, called (Pre-Sense Rear), is designed to reduce the consequences of rear-end collisions. The sunroof and windows are closed and seat belts are prepared for impact. The optional memory seats are moved forward to protect the car’s occupants. The system uses radar and video sensors and was introduced in 2010 on the 2011 Audi A8.

Ford

Collision Warning with Brake Support on the 2009 Lincoln MKS
Ford’s Collision Warning with Brake Support was introduced in 2009 on the Lincoln MKS and MKT and the Ford Taurus. This system provides a warning through a Head Up Display that visually resembles brake lamps. If

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the driver does not react, the system pre-charges the brakes and increases the brake assist sensitivity to maximize driver braking performance.

Honda
Honda’s Collision Mitigation Brake System (CMBS, although originally introduced with the initials CMS) introduced in 2003 on the Inspire and later in Acura, Honda’s luxury brand in Canada and the United States, uses a radar-based system to monitor the situation ahead and provide automatic braking if the driver does not react to a warning in the instrument cluster and a tightening of the seat belts. The Honda system was the world’s first production system to provide automatic braking.
The 2003 Honda system also incorporated an ”E-Pretensioner”, which worked in conjunction with the CMBS system with electric motors on the seat belts.
When activated, the CMBS has three warning stages. The first warning stage includes audible and visual warnings to brake. If ignored, the second stage would include the E-Pretensioner’s tugging on the shoulder portion of the seat belt two to three times as an additional tactile warning to the driver to take action. The third stage, in which the CMBS predicts that a collision is unavoidable, includes full seat belt slack takeup by the E-Pretensioner for more effective seat belt protection and automatic application of the brakes to lessen the severity of the predicted crash. The E-Pretensioner would also work to reduce seat belt slack whenever the brakes are applied and the brake assist system is activated.
In late 2004, Honda developed an Intelligent Night Vision System, which highlights pedestrians in front of the vehicle by alerting the driver with an audible chime and visually displaying them via HUD. The system only works in temperatures below 30 degrees Celsius (86 Fahrenheit). This Intelligent
Night Vision first appeared on the Legend.

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Chapter 3

OVERVIEW AND
MOTIVATION OF WORK
Our project aims at providing accident avoidance system for Indian roads with minimum possible cost affordable to common man and in the most basic vehicle variant as well.
The project uses GPS technology to detect the accident-prone locations on the traversing route by comparing the GPS coordinates of current location with those stored in the database.
It does not make use of any sensors technology for detection as being used in cars currently but uses navigation GPS technology for accident avoidance increasing the applicability of GPS technology and reducing requirement of other equipment, thus reducing cost.

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Chapter 4

GPS TECHNOLOGY
A satellite navigation or sat nav system is a system of satellites that provide autonomous geo-spatial positioning with global coverage. It allows small electronic receivers to determine their location (longitude, latitude, and altitude) to high precision (within a few metres) using time signals transmitted along a line-of-sight by radio from satellites. The signals also allow the electronic receivers to calculate the current local time to high precision, which allows time synchronisation. A satellite navigation system with global coverage may be termed a global navigation satellite system or
GNSS.
As of April 2013, only the United States NAVSTAR Global Positioning
System (GPS) and the Russian GLONASS are global operational GNSSs.
China is in the process of expanding its regional Beidou navigation system into the global Compass navigation system by 2020.[1] The European
Union’s Galileo positioning system is a GNSS in initial deployment phase, scheduled to be fully operational by 2020 at the earliest.[2] France, India and Japan are in the process of developing regional navigation systems.
Global coverage for each system is generally achieved by a satellite constellation of 2030 medium Earth orbit (MEO) satellites spread between several orbital planes. The actual systems vary, but use orbital inclinations of ¿50 and orbital periods of roughly twelve hours (at an altitude of about 20,000 kilometres (12,000 mi)).

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Chapter 5

History and theory

Figure 5.1: Accuracy of Navigation System
Early predecessors were the ground based DECCA, LORAN, GEE and
Omega radio navigation systems, which used terrestrial longwave radio transmitters instead of satellites. These positioning systems broadcast a radio pulse from a known ”master” location, followed by repeated pulses from a number of ”slave” stations. The delay between the reception and sending of the signal at the slaves was carefully controlled, allowing the receivers to compare the delay between reception and the delay between sending. From this the distance to each of the slaves could be determined, providing a fix.
The first satellite navigation system was Transit, a system deployed by the
US military in the 1960s. Transit’s operation was based on the Doppler effect: the satellites traveled on well-known paths and broadcast their signals on a well known frequency. The received frequency will differ slightly from the broadcast frequency because of the movement of the satellite with
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respect to the receiver. By monitoring this frequency shift over a short time interval, the receiver can determine its location to one side or the other of the satellite, and several such measurements combined with a precise knowledge of the satellite’s orbit can fix a particular position.
Part of an orbiting satellite’s broadcast included its precise orbital data.
In order to ensure accuracy, the US Naval Observatory (USNO) continuously observed the precise orbits of these satellites. As a satellite’s orbit deviated, the USNO would send the updated information to the satellite.
Subsequent broadcasts from an updated satellite would contain the most recent accurate information about its orbit.
Modern systems are more direct. The satellite broadcasts a signal that contains orbital data (from which the position of the satellite can be calculated) and the precise time the signal was transmitted. The orbital data is transmitted in a data message that is superimposed on a code that serves as a timing reference. The satellite uses an atomic clock to maintain synchronization of all the satellites in the constellation. The receiver compares the time of broadcast encoded in the transmission with the time of reception measured by an internal clock, thereby measuring the time-of-flight to the satellite. Several such measurements can be made at the same time to different satellites, allowing a continual fix to be generated in real time using an adapted version of trilateration: see GNSS positioning calculation for details. Each distance measurement, regardless of the system being used, places the receiver on a spherical shell at the measured distance from the broadcaster.
By taking several such measurements and then looking for a point where they meet, a fix is generated. However, in the case of fast-moving receivers, the position of the signal moves as signals are received from several satellites. In addition, the radio signals slow slightly as they pass through the ionosphere, and this slowing varies with the receiver’s angle to the satellite, because that changes the distance through the ionosphere. The basic computation thus attempts to find the shortest directed line tangent to four oblate spherical shells centered on four satellites. Satellite navigation receivers reduce errors by using combinations of signals from multiple satellites and multiple correlators, and then using techniques such as Kalman filtering to combine the noisy, partial, and constantly changing data into a single estimate for position, time, and velocity.

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Chapter 6

Global navigation systems

Figure 6.1: Global navigation systems
Comparison of GPS, GLONASS, Galileo and Compass (medium earth orbit) satellite navigation system orbits with the International Space
Station, Hubble Space Telescope and Iridium constellation orbits, Geostationary Earth Orbit, and the nominal size of the Earth. The Moon’s orbit is around 9 times larger (in radius and length) than geostationary orbit.

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Figure 6.2: Launched GNSS satellites 1978 to 2012

6.1

Operational GPS

Main article: Global Positioning System
The United States’ Global Positioning System (GPS) consists of up to 32 medium Earth orbit satellites in six different orbital planes, with the exact number of satellites varying as older satellites are retired and replaced. Operational since 1978 and globally available since 1994, GPS is currently the world’s most utilized satellite navigation system.

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Chapter 7

SYSTEM DESIGN
7.1

BLOCK DIAGRAM

Figure 7.1: SRAAC-GPS BLOCK DIAGRAM

7.2

DESCRIPTION

The driver first has to start the system and select route i.e. source and destination. The system will start scanning the locations on the route and collect coordinates in NMEA format. The database contains only the coordinates of accident prone locations. The system then compares real-time coordinates extracted from the NMEA sentence with the coordinates stored in database as the vehicle traverses ahead on the route. When any of the
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location matches with the coordinates in database, it gives an audio-visual alert to the driver indicating he is approaching an accident-prone area and needs to be cautious. The audio message is stored in the voice recording
IC APR 9600. The GPS module provides the NMEA statement. The Microcontroller ATMEL 89C51 extracts the latitude and longitude from the
NMEA statement using the program stored and compares it with the coordinates in database.

7.3

CIRCUIT DIAGRAM

Please see figure 7.2 on page 12 and figure 7.3 on page 13.

7.4
7.4.1

IMPLEMENTATION
HARDWARE

Please see figure 7.4 and figure 7.5 on page 14.

7.4.2

SOFTWARE

ALGORITHM : ( MAIN PROGRM )
1. Start
2. Select route
3. Start of engine.
4. Start scanning locations
5. Start to getting coordinates
6. Compare it with next location (i+1) stored in database (consider location once scanned and matched asi.
7. If location matches with database points
• Check if it is a last point or not?
– If yes
Stop engine, stop scanning, reset the system (i.e., go to step
1)
– Otherwise, Display current position coordinates
8. Otherwise go to step 4 above

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Figure 7.2: Interfacing of Microcontroller with GPS module & LCD

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Figure 7.3: APR 9600 Circuit Diagram

Figure 7.4: PCB Layout-1

Figure 7.5: PCb Layout-2
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THE DATABASE CVONTATTINS
1. Route wise accident-prone coordinates
2. Only the blind turns information on selective rout will be accessible
3. Database should be updated if required
PROGRAMMING STEPS:
1. Set the baud rate of PICs USART to 4800 bps.
2. Enable the SPEN and CREN bits (RCSTA register).
3. Receive the Serial data and compare with the string $GPGGA, byte by byte.
4. Wait for comma (,) as string gets matched.
5. Store the data which appears after the above comma into a string which will be the Latitude.
6. After another comma (,), store the data into another string which will be the Longitude.
7. Display both Latitude and Longitude data on LCD.
8. Repeat the steps 3 to 7 to update the GPS modules positions on LCD.

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Chapter 8

GPS TECHNOLOGY
8.1

What is GPS?

Originally conceived as a navigation aid for the military, the Global Positioning System, or GPS, has since grown from relatively humble beginnings as different supporting technologies have been developed, some off which are within reach of consumer budgets.
All that GPS does is provide a set of coordinates which represent the location of the GPS unit with respect to its latitude, longitude and elevation on planet Earth. It also provides time, which is as accurate as that given by an atomic clock.
The actual application of the GPS technology is what leads to such things as navigation systems, GPS tracking devices, GPS surveying and GPS mapping. GPS in itself does not provide any functionality beyond being able to receive satellite signals and calculate position information. But it does that very well!
GPS stands for Global Positioning system. It is a space based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the earth where there is an unobstructed line of sight (LOS) to four or more GPS satellites. GPS receiver calculates its position by precisely timing the signals sent by GPS satellites high above the earth. Each satellite continually transmits messages that include :(a): time the message was transmitted. (b): satellite position at the time of message transmission. The receiver uses messages to determine transit time of each message and computes distance of each satellite using speed of light.
Each of these distances and satellites locations define a sphere. The receiver is on the surface of each of these spheres when the distances are correct.

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These distances and satellites locations are used to compute location of receiver using navigation equations. This location is then displayed perhaps with a moving map display or latitude and longitude. Hardware interface for GPS units is designed to meet NMEA requirements. They are also compatible with most computer serials ports using RS-232 protocols.
GPS manufacturers have their own ways of interpreting NMEA standards.
Most computer programs that provide real time position information understand and expect data to be in NMEA format. This data includes the complete Position Velocity Time (PVT) solution computed by the GPS receiver.
The idea of NMEA is to send a line of data called a sentence that is totally self-contained and independent from other sentences. There are standard sentences for each device category and there is also the ability to define proprietary sentences for use by individual companies.

8.2

How it Works ?

The actual principle of GPS is very easy to appreciate, since it is exactly the same as traditional triangulation (although this is not quite correct, as
GPS does not use angles). If one imagines an orienteer needing to locate themselves on a map, they first need to be able to find at least three points that they recognize in the real world, which allows them to pinpoint their location on the map.
They can then measure, using a compass, the azimuth that would be needed to take them from the point on the map totheir current position. A line is then drawn from each of the three points, and where the three lines meet is where they are on the map.
Translating this into the GPS world, we can replace the known points with satellites, and the azimuth with time taken for a signal to travel from each of the known points to the GPS receiver. This enables the system to work out roughly where it is located - it is where the circles representing the distance from the satellite, calculated on the basis of the travel time of the signal, intersect. Of course, this requires that the GPS locator has the same coordinated time as the satellites, which have atomic clocks on board. To do this, it cross checks the intersection of the three circles with a fourth circle, which

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it acquires from another satellite.
If the four circles no longer intersect at the same point, then the GPS system knows that there is an error in its clock, and can adjust it by finding one common value (one second, half a second and so on) that can be applied to the three initial signals which would cause the circles to intersect in the same place.
Behind the scenes, there are also many complex calculations taking place which enable the system to compensate for atmospheric distortion of the signals, and so forth, but the principle remains the same.

8.3

Tracking Devices

One of the easiest applications to consider is the simple GPS tracking device; which combines the possibility to locate itself with associated communications technologies such as radio transmission and telephony.
Tracking is useful because it enables a central tracking centre to monitor the position of several vehicles or people, in real time, without them needing to relay that information explicitly. This can include children, criminals, police and emergency vehicles, military applications, and many others.
The tracing devices themselves come in different flavours. They will always contain a GPS receiver, and GPS software, along with some way of transmitting the resulting coordinates. GPS watches, for example, tend to use radio waves to transmit their location to a tracking center, while GPS phones use existing mobilephone technology.
The tracking centre can then use that information for co-ordination or alert services. One application in the field is to allow anxious parents to locate their children by calling the tracking station - mainly for their peace of mind.
GPS vehicle tracking is also used to locate stolen cars, or provide services to the driver such as locating the nearest petrol station. Police can also benefit from using GPS tracing devices to ensure that parolees do not violate curfew, and to locate them if they do.

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8.4

Navigation Systems

Once we know our location, we can, of course, find out where we are on a map, and GPS mapping and navigation is perhaps the most well-known of all the applications of GPS. Using the GPS coordinates, appropriate software can perform all manner of tasks, from locating the unit, to finding a route from A to B, or dynamically selecting the best route in real time.
These systems need to work with map data, which does not form part of the
GPS system, but is one of the associated technologies that we spoke of in the introduction to this article. The availability of high powered computers in small, portable packages has lead to a variety of solutions which combines maps with location information to enable the user to navigate.
One of the first such applications was the car navigation system, which allows drivers to receive navigation instructions without taking their eyes off the road, via voice commands.
Then there are handheld GPS units, such as those from Garmin and Magellan and a dozen other manufacturers, which are commonly used by those involved in outdoor pursuits, and only provide limited information such as the location, and possibly store GPS waypoints. A waypoint being a location that is kept in memory so that the unit can retrace the same path at a later time.
More advanced versions include aviation GPS systems, which offer specific features for those flying aircraft, and marine GPS systems which offer information pertaining to marine channels, and tide times, etc.
These last two require maps and mapping software which differ vastly from traditional GPS solutions, and as such can often be augmented with other packages designed to allow the user to import paper maps or charts.
There are even GPS solutions for use on the golf course. Golf GPS systems help the player to calculate the distance from the tee to the pin, or to know exactly where they are with relation to features such as hidden bunkers, water hazards or greens. Again, specific maps are needed for such applications.

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8.5

ADVANTAGES AND APPLICATIONS OF
GPS

The Many Benefits and Applications of GPS systems.
In order to fully appreciate the various possibilities that the GPS technology offers consumers, one first needs to be aware of exactly what the applications and benefits are of this important technology.
This article discusses what GPS is, how it works, and what current uses have been found for it that can be acquired on the general market. Of course, there are new applications being developed all the time, as the technological environment becomes more advanced.

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Chapter 9

Nmea Format
9.1

INTRODUCTION

The National Marine Electronics Association (NMEA) is a non-profit association of manufacturers, distributors, dealers, educational institutions, and others interested in peripheral marine electronics occupations. The NMEA
0183 standard defines an electrical interface and data protocol for communications between marine instrumentation. NMEA stands for National Marine
Electronics Association. It is a specification which acts as an interface between various pieces of marine electronic equipment.

9.2

ELECTRICAL INTERFACE

NMEA 0183 devices are designated as either talkers or listeners (with some devices being both), employing an asynchronous serial interface with the following parameters:
1. Baud rate: 4800
2. Number of data bits: 8 (bit 7 is 0)
3. Stop bits: 1 (or more)
4. Parity: none
5. Handshake: none

9.3

GENERAL SENTENCE FORMAT

All data is transmitted in the form of sentences. Only printable ASCII characters are allowed, plus CR (carriage return) and LF (line feed). Each sentence starts with a ”$” sign and ends with < LF>. There are three basic kinds of sentences: talker sentences, proprietary sentences and
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query sentences.
GPS manufacturers have their own ways of interpreting NMEA standards.
Most computer programs that provide real time position information understand and expect data to be in NMEA format. This data includes the complete Position Velocity Time (PVT) solution computed by the GPS receiver. The idea of NMEA is to send a line of data called a sentence that is totally self-contained and independent from other sentences. There are standard sentences for each device category and there is also the ability to define proprietary sentences for use by individual companies.

9.4
9.4.1

EXAMPLES OF NMEA SENTENCES
BOD Bearing Waypoint to Waypoint:

1. Bearing Degrees, TRUE
2. T = True
3. Bearing Degrees, Magnetic
4. M = Magnetic
5. TO Waypoint
6. FROM Waypoint
7. Checksum

9.4.2

GGA Global Positioning System Fix Data. Time, Position and fix related data for a GPS receiver

1. Time (UTC)
2. Latitude
3. N or S (North or South)
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4. Longitude
5. E or W (East or West)
6. GPS Quality Indicator,
- 0 - fix not available,
- 1 - GPS fix,
- 2 - Differential GPS fix
7. Number of satellites in view, 00 - 12
8. Horizontal Dilution of precision
9. Antenna Altitude above/below mean-sea-level (geoid)
10. Units of antenna altitude, meters
11. Geoidal separation, the difference between the WGS-84 earth ellipsoid and mean-sea-level (geoid), ”-” means mean-sea-level below ellipsoid
12. Units of geoidal separation, meters
13. Age of differential GPS data, time in seconds since last SC104 type 1 or 9 update, null field when DGPS is not used
14. Differential reference station ID, 0000-1023
15. Checksum

9.4.3

RMC Recommended Minimum Navigation Information

1. Time (UTC)
2. Status, V = Navigation receiver warning
3. Latitude
4. N or S
5. Longitude
6. E or W

25

7. Speed over ground, knots
8. Track made good, degrees true
9. Date, ddmmyy
10. Magnetic Variation, degrees
11. E or W
12. Checksum

9.4.4

GSV Satellites in view

1. total number of messages
2. message number
3. satellites in view
4. satellite number
5. elevation in degrees
6. azimuth in degrees to true
7. SNR in dB more satellite infos like 4)-7)
n. Checksum

9.4.5

ZDA Time and Date
Local Time Zone

UTC, Day, Month, Year and

1. Local zone minutes description, same sign as local hours
2. Local zone description, 00 to +/- 13 hours
3. Year

26

4. Month, 01 to 12
5. Day, 01 to 31
6. Time (UTC)
7. Checksum

9.4.6

GLL Geographic Position Latitude/Longitude

We propose to use the GLL command for obtaining GPS location coordinates information(i.e. Latitude and Longitude), in our project. GLL stands for Geographic Position- Latitude/Longitude. Its format is as given below:

1. Latitude
2. N or S (North or South)
3. Longitude
4. E or W (East or West)
5. Time (UTC)
6. Status A - Data Valid, V - Data Invalid
7. Checksum

9.5

APPLICATIONS OF NMEA

1. Marine Electronics.
2. Marine Communication.
3. Obtaining GPS coordinates from the satellites.
4. Establishing shipboard connection with the ports.

27

Chapter 10

Project Advantages And
Limitations
10.1

ADVANTAGES

1. Accuracy in detection of accident-prone regions and blind turns due to high refresh rate of GPS module.
2. User gets an audio warning for forthcoming blind turn. Also, the user gets a visual indication on the LCD display for the same.
3. The circuitry is quite compact and light-weighted.
4. Provides real time location.
5. Avoid major accidents and make road travel much safer.
6. Helps driver to get accurate direction of destination and saves time in finding destination.
7. System is completely user friendly.
8. Store information and helps in safe driving.

10.2

LIMITATIONS

1. The major drawback is that system faces problem if no coverage is available for GPS.
2. Speed control completely lies with the driver and hence system falls short in reducing vehicle speed if the driver does not heed the warning.

28

Chapter 11

APPLICATIONS AND
FUTURE SCOPE
11.1

APPLICATIONS

1. This system can be used for all cars.
2. It can also be used for accident avoidance in heavy vehicles like trucks.
3. SRAAC-GPS also finds an application in railways to indicate approaching stations.

11.2

FUTURE SCOPE

1. By modifying the gear box of cars, automatic speed control can be implemented for a more secure system and for more effective results.
2. Enhancement can be made using GSM to notify the nearby traffic police controller if a vehicle crosses the safety speed limits and do not heed the system warning.

29

Chapter 12

CONCLUSION
The system designed gives an audio warning whenever the car approaches an accident- prone region. In addition, it also provides a visual display alerting the driver regarding impending blind turns. There is an extensive scope for future enhancements for this project as well. This user-friendly, easyto-install system provides excellent road security and hence will succeed in reducing road mishaps.
Thus, overall objective of our project has been successfully achieved.

30

Chapter 13

APPENDIX A: GPS
MODULE
1.

Product Part I.D.:

2.

Product Description

EM-408

GPS Module comes with a POT (Patch On Top) ceramic antenna which makes it a small and complete solution for enabling GPS navigation to your embedded devices and robots. It supports 66 Channels and external antenna input compatibility for maximum sensitivity.
Module comes with a standard 2mm DIP pin headers which provides easy interface to your device. The module works on TTL Serial protocol which used with any microcontroller or PC. USB cable is included to connect with PC USB port. It can be directly pluged to USB and can be connected to softwares like trimble studio.

Figure 13.1: EM 408-GPS Engine Board

31

The EM-408 is a popular GPS module that suits hobbyist type projects.
It comes complete with a built in antenna and connecting cable, is available reasonably cheaply from many sources and, most importantly, just works without too much drama. For those who dont know what it does: It uses the GPS satellite system to report your current latitude, longitude, altitude, speed and much more, all in a small package about one inch square.
3.

Connections
There are 5 connections to the module. These are:
- Ground
- Supply Voltage (3.3V)
- Transmit Data (ie, data from the module)
- Receive Data (ie, commands sent to the module)
- Enable (this is a battery input on the EM-0408E version).
The Enable signal is active high (ie, pulling it high will enable the module, pulling it low will put the module to sleep). If you are not using Enable you must pull it high with a 4.7K resistor. Letting it float will disable the module. Some documentation states that the Receive
Data line should also be pulled high for the module to work. This is not necessary as the Receive Data line has an 12K (approx) resistor internally pulling the line up to the Supply Voltage.

4.

Pin Assignment

Figure 13.2: EM-408 Pin Assignment

32

5.

Pin Explanation
ENABLE/DISABLE: On / Off
VCC: (DC power input) This is the main DC supply for a 3.3V power module board.
TX: This is the main transmit channel for outputting navigation and measurement data to users navigation software or user-written software. RX: This is the main receive channel for receiving software commands to the engine board from SiRfDemo software or from user-written software. (NOTE: When not in use this pin must be kept HIGH for operation. From Vcc connect a 470 Ohm resistor in series with a 3.2v Zener diode to Ground.Then, connect the Rx input to Zeners cathode to pull the input HIGH.)
GND: GND provides the ground for the engine boards. Be sure to connect all grounds.

6.

Product Specifications
The specifications are as follows:

33

Table 13.1: EM-408 Specification
GPS Receiver
Chipset
Frequency
Code
Protocol

SiRF Star III/LP Single
L1, 1575.42 MHz
1.023 MHz chip rate
Electrical Level: TTL level
Output Voltage Level: 0V 2.85V
Baud Rate: 4800 bps 57,600bps
(adjustable)
Output Message: NMEA 0183 GGA, GSA,
GSV, RMC (VTG, GLL optional)
Channels
20
Sensitivity
-159dBm
Cold Start
42 seconds average
Warm Start
38 seconds average
Hot Start
8 second average
Reacquisition
0.1 second average
Accuracy Position:
10 meters, 2D RMS
5 meters, 2D RMS, WAAS enabled
Velocity: 0.1 ms
Time: 1s synchronized to GPS time
Maximum Altitude
18,000 meters (60,000 feet) max
Maximum Velocity
515 meter/second (1000 knots) max
Maximum Acceleration 4G
Datum
WGS-84
Jerk Limit
20m/sec **3
Physical Characteristics
Dimensions
1.4x1.4x0.3(36.4x35.4x8.3)
Power Supply
3.3V DC Input
Power Consumption
44mA (Continuous Mode)
25mA (Trickle Power Mode)
Humidity Range
5% to 95% non-condensing
Operation Temperature -40F to +185F (-40C to 85C)

34

Chapter 14

APPENDIX B: APR 9600
RE-RECORDING VOICE
IC
1

Features :
• Single-chip, high-quality voice recording playback solution
- No external ICs required
- Minimum external components
• Non-volatile Flash memory technology
- No battery backup required
• User-Selectable messaging options
- Random access of multiple fixed-duration messages
- Sequential access of multiple variable-duration messages
• User-friendly, easy-to-use operation
- Programming development systems not required
- Level-activated recording edge-activated play back switches
• Low power consumption
- Operating current: 25 mA typical
- Standby current: 1 uA typical
- Automatic power-down
• Chip Enable pin for simple message expansion

2 General Description :
The APR9600 device offers true single-chip voice recording,nonvolatile storage, and playback capability for 40 to 60 seconds.The

35

device supports both random and sequential access of multiple messages.Sample rates are user-selectable,allowing designers to customize their design for unique quality and storage time needs.Integrated output amplifier,microphone amplifier, and AGC circuits greatly simplify system design. The device is ideal for use in portable voice recorders, toys, and many other consumer and industrial applications.
APLUS integrated achieves these high levels of storage capability by using its proprietary analog/multilevel storage technology implemented in an advanced Flash non-volatile memory process, where each memory cell can store 256 voltage levels. This technology enables the APR9600 device to reproduce voice signals in their natural form. It eliminates the need for encoding and compression, which often introduce distortion.

3 PIN DIAGRAM :

Figure 14.1: APR 9600 Pin Configuration

4 Functional Description :

36

APR9600 block diagram is included in order to describe the device’s internal architecture. At the left hand side of the diagram are the analog inputs. A differential microphone amplifier, including integrated AGC, is included on-chip for applications requiring use.The amplified microphone signals fed into the device by connecting the ANA OUT pin to the ANA IN pin through an external DC blocking capacitor. Recording can be fed directly into the ANA IN pin through a DC blocking capacitor, however, the connection between ANA IN and ANA OUT is still required for playback. The next block encountered by the input signal is the internal anti-aliasing filter. The filter automatically adjust its response according to the sampling frequency selected so Shannons Sampling Theorem is satisfied. After anti-aliasing filtering is accomplished the signal is ready to be clocked into the memory array. This storage is accomplished through a combination of the Sample and Hold circuit and the Analog Write/Read circuit.
These circuits are clocked by either the Internal Oscillator or an external clock source. When playback is desired the previously stored recording is retrieved from memory, low pass filtered, and amplified as shown on the right hand side of the diagram. The signal can be heard by connecting a speaker to the SP and SP pins. Chip-wide management is accomplished through the device control block shown in the upper right hand corner. Message management is provided through the message control block represented in the lower center of the block diagram.

37

Chapter 15

APPENDIX C: ATMEL
89C51
MICROCONTROLLER

38

Chapter 16

APPENDIX D: LM 386
AUDIO AMPLIFIER

39