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Fleet Management: A GPS-GIS integrated approach
Proposed work
It is planned to install GPS receivers on the battery-driven, eco-friendly internal vehicles in the IIT Bombay campus to be able to monitor their performance and provide locational information to all users. A major problem encountered was the canopy and multi-path complication due to buildings on either side of the route on which the vehicles ply and the heavy leaf coverage. A pilot test was conducted to check on the availability of signals in the navigation mode using the simplest procedure. Trimble GeoExplorer3 hand-held receivers were used to map the campus roads by collecting data walking at a steady pace. No differential correction was applied to check for results in the worst possible case. The results obtained were surprisingly quite well suited for our purpose. The GPS data was downloaded and processed using the Trimble Pathfinder Office 2.8 software that plotted the roads and the few select points that were mapped in static mode (Figure 1).  Figure 1: GPS data plotted by the Pathfinder Office 2.8 processing software. The dilution parameters were downloaded for all the static points and a statistical analysis of the Positional (PDOP), Vertical (VDOP), Horizontal (HDOP) and Time (TDOP) dilution of precision values showed least correlation between PDOP and HDOP. Hence, the parameters of PDOP and Horizontal Accuracy (in meters) for all the points on the route of the internal vehicles were considered for monitoring. The GPS data was exported from the Pathfinder Office to ArcView GIS version 3.1 as a shape file and a database file. The vehicle-plying route was plotted as one theme and the other roads as another one. The static points with attributes have also been shown in the figures that follow. The PDOP (Figure 2) and horizontal accuracy parameters (Figure 3) were plotted for each point on the route using a colour gradation method in the ArcView GIS. As is clear from the 2 figures, the blue and pink coloured region (denoting PDOP 6.3 to 13.1 and Horizontal Accuracy 7.33 to 16.8 meters) is the critical region as confirmed by both the figures. The remaining areas have PDOP range 2 to 6.3 and Horizontal accuracy 5.7 to 7.3 m, which is acceptable for our purpose of tracking the vehicle positions.  Figure 2: PDOP variation along the route. |