Abstract | Full Paper | PDF Intelligent Tracking, Navigation and Guidance System for Vehicles Hemraj S.N.Mohapatra, Amar Kumar Swain, Vipin Kumar Soni Anurag Ohri,Saroj Kumar Das Automatic Vehicle tracking system/navigation system is a technologically advanced method of remote vehicle tracking/navigation and monitoring using GPS. It utilizes the recent advancements in telematics. To be more precise, the word telematics is a combination of telecommunication and informatics. Generally, telematics refers to systems and services that link vehicles with external elements through information communication technology. Few years back, car navigation systems were self-contained in the vehicle. In recent years, however, car navigation systems are expanding and linked to an information center such as central server location, through a mobile communication system. There are various types of services which could be provided, including route guidance, fleet tracking, geofencing, emergency rescue, chasing of stolen vehicle, remote monitoring of City Transport Management system and tourist guidance etc. Aim of this paper is to demonstrate the designing of a hardware prototype which is economical, accurate, robust and user friendly. Objective: The system described here is a design of a prototype which is very convenient to install and too easy to configure. Each system is equipped with 12 channel GPS module that receives signals from series of satellites, calculates its current geographical location and, transmits to a central Server where it is displayed on a high resolution geographical map. The data is transmitted instantaneously after capturing (Real Time Tracking). APPLICATION SCENARIO: Basically this system comprises of three elements. A GPS receiver GSM Communication Module Central Server GPS Receiver: The Global Positioning System (GPS) is a worldwide radio-navigation system formed from a constellation of 24 satellites and their ground stations. GPS receivers have been miniaturized to just a few integrated circuits and so are becoming very economical. And that makes the technology accessible to virtually everyone. GPS provides continuous coverage. Also, rather than Doppler shift, satellite range is determined from phase difference. There are two types of observables. One is pseudorange, which is the offset between a pseudorandom noise (PRN) coded signal from the satellite and a replica code generated in the user's receiver, multiplied by the speed of light. The other is accumulated delta range (ADR), which is a measure of carrier phase. The determination of position may be described as the process of triangulation using the measured range between the user and four or more satellites. The ranges are inferred from the time of propagation of the satellite signals. Four satellites are required to determine the three coordinates of position and time. The time is involved in the correction to the receiver clock and is ultimately eliminated from the measurement of position. High precision is made possible through the use of atomic clocks carried on-board the satellites. Each satellite has two cesium clocks and two rubidium clocks, which maintain time with a precision of a few parts in 1013 or 1014 over a few hours, or better than 10 nanoseconds. In terms of the distance traversed by an electromagnetic signal at the speed of light, each nanosecond corresponds to about 30 centimeters. Thus the precision of GPS clocks permits a real time measurement of distance to within a few meters. With post-processed carrier phase measurements, a precision of a few centimeters can be achieved. The design of the GPS constellation had the fundamental requirement that at least four satellites must be visible at all times from any point on earth. The tradeoffs included visibility, the need to pass over the ground control stations in the United States, cost, and sparing efficiency. The operational system, as presently deployed, consists of 21 primary satellites and 3 on-orbit spares, comprising four satellites in each of six orbital planes. Each orbital plane is inclined at 55. This constellation improves on the "18 plus 3" satellite constellation by more fully integrating the three active spares. Here's how GPS works in five logical steps: The basis of GPS is "triangulation" from satellites. To "triangulate," a GPS receiver measures distance using the travel time of radio signals. To measure travel time, GPS needs very accurate timing which it achieves with some tricks. Along with distance, you need to know exactly where the satellites are in space. High orbits and careful monitoring are the secret. Finally you must correct for any delays the signal experiences as it travels through the atmosphere. In the present prototype we are using a GPS with SIRF architecture which fulfill all accuracy requirements required. With its rapid time-to-first-fix and high sensitivity, the SiRFstar architecture is designed to meet the rigorous demands of wireless and handheld LBS applications, and provides superior location performance, both indoors and out, for 2G, 2.5G, 3G asynchronous networks. The SiRFstar architecture packs a performance punch, achieving time-to-first-fix of one second for aided starts in outdoor GSM environments and acquiring signals down to -159 dBm. This makes real-time navigation practical, including in many indoor environments, through urban canyons, and under dense foliage. Unlike the lengthy sequential search process of traditional GPS architectures, the SiRFstar architecture, with the equivalent of more than 200,000 correlators, enables fast and deep GPS signal search capabilities, resulting in significant improvement over today's architectures that contain a few hundred to a few thousand correlators. The output of this GPS is in the forms of NMEA codes, the details of the code and what they signify is as follows: The GGA/RMC-Global Positioning System Fix Data describes Time, position and fix related data for a GPS receiver. Format: $GPGGA,HHMMSS.sss,DDMM.mmm,d,DDDMM.mmm,d,q,ss,h.h,a.a,z,,,,*CC $GPRMC,HHMMSS.sss,a,DDMM.mmm,d,DDMM.mmm,d,z.z,y.y,ddmmyy,d.d,v *hh<CR><LF> NULL Geoidal separation (Not supported) NULL Units of geoidal separation (Not yet supported) x.x Age of Differential GPS data(NULL) Xxxx Differenttial reference station ID *CC<CR><LF> Check Sum and sentence termination delimiter Ex 1.: $GPGGA,084131.430,2505.9144,N,12145.0509,E,1,05,2.0,59.1,M,,,,0000*38 Ex 2.: $GPRMC,084119.430,A,2505.9101,N,12145.1214,E,19.80,265.26,260799,,*39 **Checksum Field: The absolute value calculated by exclusive-OR the 8 data bits of each character in the Sentence, between, but excluding "$" and "*".The hexadecimal value of the most significant and least significant4 bits of the result are converted to two ASCII characters ( 0-9,A-F ) for transmission. The most significant character is transmitted first. GGA Time, position and fix type data. GLL Latitude, longitude, UTC time of position fix and status. GSA GPS receiver operating mode, satellites used in the position solution And DOP values. GSV The number of GPS satellites in view satellite ID numbers, elevation, Azimuth and SNR values. RMC Time, date, position, course and speed data. VTG Course and speed information relative to the ground. GSM Communication Module: The NMEA data from GPS Receiver is then fed to an interfacing circuit. This circuit acts as a bridge between GPS & GSM Communication Module .This circuit reads the NMEA data from the GPS and sends it out via the GSM phone as an SMS. The GSM Communication Module is designed with the help of a GSM mobile Phone or a GSM Modem, Which contains a SIM card. Main purpose of this communication module is to modulate the NMEA data at a level so that it can be used as SMS input to the Mobile Phone. The most important part of this GSM communication module is a high performance CMOS 8-bit microcontroller. This is a low voltage (2.7V - 6V) Microcontroller with 2 Kbytes of Flash programmable and erasable read only memory (PEROM). It provides the following features: · 2 Kbytes of Flash · 15 I/O lines · two16-bit timer/counters · five vector, two-level interrupt architecture · full duplex serial port · precision analog comparator · on chip oscillator and clock circuitry In addition, the 2051 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset. Atmel 89C 2051 To interface the data from GPS to GSM mobile phone a standard serial interfacing occasionally used for PC, i.e. RS232C has been utilized which requires negative logic, i.e., logic '1' is -3V to -12V and logic '0' is +3V to +12V. To convert a TTL logic, say, TxD and RxD pins of the Microprocessor chip (AT89c2051), we need a converter chip. Hence MAX232 chip has been used here. It provides 2-channel RS232C port and requires external 10uF capacitors. (3.) Central Server The Central Server has GSM Modem interfaced with a PC and supporting softwares along with relevant database. At central server we receive the data sent from vehicles as SMS .A typical SMS may contain following DATA. $GPRMC,060933,A,2830.0772,N,07705.1572,E,0.05,54.39,220704,*,0.8.E*78 Navigation data can be interpreted as follows."$GPRMC" is protocol-header; data was sent at UTC:06:09:33(hhmmss);"A" marks data to be valid ("V" would mean: INVALID);"2830.0772,N" is latitude (ddmm,mmm) NORTH and "07705.1572,E" is longitude (ddmm,mmm)EAST;"0.05,54" is speed (Knots) and "54.39"is heading(degrees);"220704" is date of data recorded (July 22nd ,2004);"0.8,E" is magnetic declination. Protocol is completed by sending checksum "78". Installation of GPS in Vehicle: As the size of the GPS/GSM Module is very small it can be easily accommodated on the dashboard of vehicle .The GSM Communication module has a DB9 connector .This DB9 connector can be connected to the GSM Mobile phone whenever required. Once we get raw data it is processed with various software tools and location of the vehicle, its velocity and direction is displayed on digital map. Data stored at the central server can be analyzed through software application. A GIS mapping solution is used with features for tracking the vehicle. The application can be installed by any one of the following models: Standalone client sever or web based. · How the sending of NMEA data from GSM Communication module is initiated? There are two Methods to initiate the NMEA data transmission from GSM Communication Module. 1. By calling the GSM unit from any phone, just one ring would be enough to trigger the transmission of SMS. 2. By pushing the SEND button of the GSM communication Module. When the sending is initiated the GSM Communication Module starts sending NMEA data SMS to a predefined Mobile number, which is connected to the central server. This predefined number is programmed in GSM communication module with the help of HyperTerminal program in Windows. What Happens when SMS is received: On receiving the SMS, the server analyses the data giving information about suitable satellites in view and other necessary information. The GPS receiver in the Vehicle calculates time, pseudo ranges from the suitable satellites and extracts the necessary latitude, longitude and, altitude information required for positioning. Meanwhile the user enters to new destination, after which another SMS is composed containing the new destination and vehicle position information and sent over GSM Communication module to the mobile handset, which in turn forwards it to the server. On receipt of this SMS, the server calculates the route to the destination based on the information in the SMS by using its own resources like map database and route calculation software, real time traffic inputs etc. This Data helps us to monitor the exact location Vehicle on the digital map along with several other attributes. The GPRS advantage: If we are using a GSM service which provides GPRS enabled services then scope of this navigation/tracking system widens dramatically. General Packet Radio Service is a radio technology for GSM networks that adds packet-switching protocols, shorter set-up time for ISP connections, and offer the possibility to charge by amount of data sent rather than connect time. GPRS promises to support flexible data transmission rates typically up to 20 or 30 Kbps (with a theoretical maximum of 171.2 Kbps), as well as continuous connection to the network. With the help of GPRS we can instantly get the navigation data and route guidance on a Handheld/Miniature PC(Client) installed on the dashboard of Vehicle. By interpreting the data in the SMS, the corresponding turn maneuvers are either read out to the user through a speaker or shown on display depending on the capabilities of the client. The route tracking software in the client keeps track if the vehicle deviates from the itinerary. This is done with the help of GPS receiver and the gyroscope and requests further corrections from the server as and when required. All these information exchanges consists of few bytes of data transfer through SMS or GPRS and is quite fast as compared to standalone GPS systems (few seconds). Economical Issues: The basic hardware used to design this system is not very costly. If we calculate the cost of the System to be installed in a vehicle which includes as GPS receiver, a GSM communication Module and a simple data mode enabled GSM Cell phone then its surprisingly low .It just comes to be about Rs.12,000/- In case of mass production this cost may further be reduced . Conclusion: This basic hardware setup can be used to design a full fledge online Car navigation system.It can even be used to design online City Transportation System to monitor the location of buses and taxies. As discussed earlier we can use GPRS for this purpose. As it offers "always -on", higher capacity, internet -based content and packet based data services. This enables services such as colored internet browsing-mail on the move, powerful Visual Communications, multimedia messages and location based services along with real-time updates about the routes available to reach a particular destination. Reference: 1. www.gsmworld.com/technology/gprs 2. www.garmin.com 3. www.gpsworld.com/ 4. www.trimble.com/gps 5. www.magellangps.com/en/ 6. http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html 7.