Design of Wireless Data Acquisition System for Landslide Detection

Abstract

The mining industry is the backbone of various manufacturing and infrastructure industries. It is also one of the most dangerous professions in the world. The number of accidents in underground mines is more than in open cast mines. Roof fall, side slope fall are the main reason of accidents in underground mines. In order to maintain a safe working environment, a lot of parameters need to be monitored periodically in underground mines. The roof fall, side slope fall in underground mines occur due to rock deformation in between layers. The deformation of rock is not sudden and it happens gradually. This gradual change of rock deformation results in landslide. Rock deformation analysis and roof fall prediction in an underground mine is one of the most important safety challenges in the mining industry. Dedicated and reliable instrumentation system which comprises of a Telltale is used to assess the deformation of the rock. Visual indicators of the Telltale are used to warn the personnel inside the mine about a possible roof fall.

This thesis provides the design and implementation details of a wireless landslide detection system which provides visual warning of a possible roof fall and transmits the warning message to the working personnel having a receiver. This is useful for underground mines as wired networks incur a lot of regular maintenance. In wired network, if the wire gets broken then data from multiple sensors may get damaged. Due to this reason wired networks do not find much application in the underground mines. Using the wireless communication the operator can easily predict the danger from a distance. Currently the available instruments in the mines are mainly field indication type. The operator has to scan each and every area by physically going there. There are lot of risks involved in this scenario. The operator do not know the amount of deformation until and unless he reaches there. The sensing mechanism is built using simple clock spring-pulley architecture. Whenever there is a movement in the layers, the anchor senses it. The anchor then propagates the deformation to the pulley connected with it. Due to the rotation of the pulley the potentiometer of the shaft rotates. This resistance change is proportional to the movement in the layers. A signal conditioning system and an efficient radio-frequency (RF) transmission system is designed which makes the developed wireless landslide detection system a more effective one. The developed wireless sensor is accurate, reliable and easy to configure.

There may be a chance that the operator in underground mine may come across more than one sensor. Communicating with multiple sensors one by one is a very difficult procedure. A multiple access method makes things much simpler. A polling multiple access method has been implemented in this context to communicate with multiple transmitters at a time. Due to this efficient method the operator can scan the area using a single command. A laboratory prototype of the proposed wireless electronic Telltale system is developed to demonstrate the working principle. The sensor is much more accurate than the available system. Due to this wireless measurement the operator can scan the surrounding area and alert the possible danger situations.