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Fleet management using GPS and GIS

Pradeep Singh Kharola¹, Bipin Gopalkrishna², D.C.Prakash^3
1MD, ²Director (S&V), ³ Manager (MIS), BMTC

Abstract:
Fleet management is the most important function for any bus based public transport organization. This involves scheduling and planning of routes and at the same time ensuring that the buses run as per the schedule. This becomes exceptionally difficult in bigger cities where the number of buses involved is very high and all these buses perform repetitive trips. The failure of management in ensuring timely operations has resulted in the bus system becoming unpopular and shift in traffic to the personalized modes of transport. . However GPS based Intelligent Transport Systems provide the possibility of monitoring the movement of vehicles at an affordable cost. Presented in this paper is a system, which was evolved by the Bangalore Metropolitan Transport Corporation (BMTC) for tracking of its buses. It has been brought out that an efficient vehicle system would require the integration of two modern technologies viz. the Global Positioning System (GPS) and the Geographical Information System (GIS).

Vehicle Tracking, the essence of fleet Management
Management of a bus fleet essentially involves ensuring timely arrival and despatch of buses. To go a step further it also involves ensuring that the bus touches the enroute points as per schedule. Simple though this may sound, the magnitude of this can be gauged from the fact an Urban Transport Corporation in a city like Bangalore has 2300 buses and about 33000 trips, and these trips pass through repeatedly about 1000 bus stops in the city. In the conventional system some sort of vehicle tracking is carried out manually by posting traffic controllers/timekeepers at some important points. This manual tracking doesn't give 100% coverage, it totally depends on human alertness and is thus prone to errors, it is very expensive, it is not tamper-proof, and the data generated in the form of entries in the registers do not lend themselves easily for computer processing.

A vehicle tracking system can thus be defined as a system, which enables the fleet operator to find out the location of the vehicle throughout the journey of the vehicle, against time.

Apart from utilising the data generated by the vehicle tracking system for enforcing the schedule of the bus, this data also provides important inputs for decision making. The system facilitates computation of exact distance travelled in a given time span, computation of the speed of the bus at a given location, analysis of the time taken by the bus to cover certain distance and so on. It becomes a very powerful tool in case the Transport Corporations are hiring private buses, as computation of the distance travelled, based on which payments are made becomes totally objective.

Basics of the GPS
Global Positioning System (GPS) has three components namely

1. The space segment: consisting of 24 satellites orbiting the Earth at an altitude of 11000 nautical miles.
2. The user segment: consisting of a receiver, which is mounted on the unit whose location has to be determined.
3. The control segment: consists of various ground stations controlling the satellites.

The system is owned by the US military but they have permitted civilian use of the satellite signals. Each satellite generates radio signals that allow a receiver to estimate the distance between the satellite and the receiver. The receiver then uses these measurements to calculate its own location with reference to Earth in terms of coordinates expressed in latitude and longitude. Thus the receiver continuously records its coordinates at given time intervals. This data, which is continuously recorded, can be stored in a memory module along with the receiver, or it can also be transmitted instantaneously to the central facility. The former would be an off-line system and the latter an on-line system. The off-line system is shown in figure-2.
Figure1


Figure2

GIS, the base for GPS:
Geographical Information System (GIS) is a database system for capturing, storing, checking, integrating, manipulating, analysing and displaying data, which are spatially referenced to Earth. In simple words GIS is a computer based software capable of handling maps and various details given on the map. Data generated by the GPS is spatial data referenced to Earth. In other words this data is the coordinates of its own position expressed in latitude and longitude. This data needs to be positioned on a map of the area for any useful analysis. To be more precise a road map of the area, with important landmarks is required. On this map the GPS readings are superimposed for further processing.

Developing the Vehicle Tracking Project: Developing this project involved a multidisciplinary approach, which ranged from mapping the routes upto analyzing the results produced by the GPS. The stage involved in this process were as follows:

• Digitising the road map for the city.
• Developing the GPS receiver module.
• Development of software, which provides interface between the GIS and the GPS.
• Development of the error correction software.
• Development of the analysis software.

Digitising the road map:
The first step of this project was the digitisation of the road map of the city. Though numerous maps were available including the official map published by the Surveyor General of India, these maps were not suitable as the latest roads were not marked on them and moreover an exact map covering the entire area, which is serviced by the city buses was not available. Therefore recourse was made to the satellite images provided by ISRO.


Figure3

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