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AutoDESPATCH: GPS based Mine Production Monitoring System
Kartikeya Verma,
V.K. Anand, Amit Kr. “Montu”,
Jai Kumar, Jayati Paul, Ashutosh Gopinath, R. P. Singh
Automation Division, Tata Steel, Jamshedpur, India
Introduction [1]:
Opencast coal-mines operate with periodic drilling, blasting and then excavations which in turn is followed by removal of Over Burden (OB) and retrieval of the coal. In the process of coal mining, two main sub processes viz. removal of OB and retrieval of coal are predominant. But most of the effort goes in the removal of OB and this has a dominant influence on the productivity. In the process of OB removal, two of the equipment viz. Rear Dumper and Excavator play a leading role. After the schedule of blasting in an specific zone of the mine has been prepared, the Excavator loads the OB into RD and each RD goes practically through four different machine states i.e. Waiting (near Loading zone), Loading, Full and Empty (at Dumping zone). This sequence of machine states of a RD constitutes one trip. Now it may be understood that to monitor the productivity automatically, one has to monitor the movement of RDs around the corresponding Excavator i.e. Loading zone to Dumping zone and back to Loading zone. For Drilling process to monitor, it is desired to capture actual depth drilled & the location of hole as per the drilling plan to achieve the optimised blasting effort. Fuel consumption is another costly component to run the mine at optimum cost and to monitor it, it is desired to capture actual fuel dispensed in different HEMMs as a result to achieve effective cost control.
AutoDESPATCH system has been designed & developed indigenously by Automation Division, Tata Steel and first implemented at Quarry SE Coal Mine of West Bokaro and also being implemented at Noamundi Iron Ore Mines of Tata Steel. The system is based GPS technology and few other sensor & Communication technologies to offer an online Mine Production Monitoring System for any opencast mines with suitable customisation. The basic system features of AutoDESPATCH are explained in the following sections.
GPS Technology [2]:
GPS is a satellite based tracking system. A total of 24 GPS satellites orbit at 11,000 nautical miles above the Earth. The satellites transmit signals that can be detected by anyone with a GPS receiver. The receiver compares its own time with the time sent by a satellite and uses the difference between the two times to calculate its distance from the satellite. By checking its time against the time of three satellites whose positions are known, a receiver could pinpoint its longitude, latitude, and altitude.
GPS technology has been adopted for use with AutoDESPATCH Field Electronics, to enable the tracking of equipment within Open Cast mines. The GPS position is used to identify the location of dumpers with respect to sources and destinations and thus automate the dumper cycle. Excavators periodically broadcast their positions. These broadcasts are received by electronics on board dumpers, which then update tables that store the excavator co-ordinates. In order to permit accuracy of the order of 5 meters, it is necessary to broadcast differential corrections to the GPS unit. The GPS engine utilised in the AutoDESPATCH field electronics used in Open Cast mines is able to cope with:
- Satellite obstruction problems and signal multi-path where filters are utilised to eliminate reflections of a cliff face.
- High walls and canyons which restrict the view of the sky to a few satellites.
- Jagged faces where satellites are reacquired in less than one second after previously being hidden from view.
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