The Underground Environmental Condition Monitoring Which Can Be Used for Various Mining Industries

In last two decades the demand and applications of various communication systems have grown drastically. In this context of communication system, wireless communication is considered as a most promising technique of communication and it has significant impact on real-time communication systems. Various researches have been presented to delineate the wireless communication which also embodies the discussion about advantages and disadvantages of wireless communication. In this field of wireless communication, sensor network based communication plays important role and it is considered as an active area of research.

These sensor nodes are used to formulate a sensor network, called as Wireless sensor network which utilizes small sensor nodes. Since, these sensor nodes are very small in size hence various limitations are also constrained such as limited memory capacity, battery capacity and processing time etc. Generally, these sensor networks are deployed in distributed manner for sensing the physical conditions of the outer world and monitor the environmental conditions such as light, weather conditions and pollution etc. These sensor networks enormously prolong the user’s ability to monitor the environmental and physical activities. Moreover, wireless sensor networks are anticipated to accommodate the solution for various applications on real-time systems such as monitoring, military purpose, disaster management and patient tracking and monitoring etc.

The augmented study of WSNs helps to serve communication better by introducing automated monitoring system. Due to increased capacity of sensor nodes, these sensor nodes are used for wide range of applications such as agriculture, geological analysis, navigation purpose and security and along with this, these networks can be used for monitoring underground conditions. Moreover, sensor networks are adopted for examine the conditions of underground infrastructures and process such as landslide detection, earthquake monitoring and information acquisition from the sensor network which is deployed in underground tunnels or mines.

In this work, we focus on the monitoring the underground environmental condition monitoring which can be used for various mining industries such as coal mining. Environment monitoring and efficient communication is considered as a crucial task which helps to ensure the safety in underground coal mines and improves the productivity. Generally, in underground coal mines, poor visibility, lower ventilation and toxic gases are present which may cause explosion resulting in huge damage and loss of capital and severe causalities. Industries urge for a significant system for provisioning advanced monitoring system which can accommodate real-time information about underground mines and miners, specifically it helps to procure the real-time location parameters of the miners which can be used for ensuring the safety of miners in emergency. In order to guarantee the safety in underground coal mining systems, Cable Monitoring System has shown a significant effect on various issues but due to complexity in underground environments, CMS technique fails to monitor the various parameters which have impact on the coal mining safety such as underground temperature, pressure, speed of wind and carbon monoxide level measurement. Moreover, it is difficult to identify the hidden dangers which become a complex task for CMS systems to overcome. In contrast, wireless sensor network based techniques can efficiently, insistently and flexibly monitor the underground mine areas which are not possible to measure by CMS systems. These systems have various limitations such as: these techniques are vulnerable to failure due to cable breakage, bad design or connectivity may lead to the sparks or flame resulting in fire, in wired systems connection cannot be established from the desired location wirelessly etc.

Generally, in dangerous situations such as disaster (fire, landslide), WSN can be considered as more reliable comparative to the wired communication systems. Wireless sensor network systems can be deployed rapidly and it has multi-hop transmission system which can provide more scalable and reliable information for underground monitoring. Furthermore, WSNs can be used to localize the miner in underground mines where other techniques require a pre-defined infrastructure for monitoring where GPS (Global Positioning Systems) are not available and implementation of GPS systems for underground coal mining becomes crucial due to implementation cost. However, WSN suffer from various issues which are responsible for affecting the performance of WSN such as medium access, deployment of sensor network, network layer, security and localization of sensor node. In this process of underground mine monitoring, sensor node localizationism considered as important task which helps to perform

network routing, location awareness and location based tacking. In underground coal mining systems, obtaining the accurate information is a challenging task hence localization technique need to be implemented for any underground WSN monitoring system which can provide the information about miners. According to WSN, any information is collected from source node and transmitted towards the destination nodes with the help of anchoring nodes. If the position of anchor node, source node and destination node is not known then the collected information may not be transmitted efficiently or information may become useless due to loss of the packets. In order to deal with this issue, GPS is a promising technique but implementation cost and complexity is a challenging task. Hence, we focus on the wireless sensor network based localization scheme. WSN localization techniques can be divided into two classes: anchor-based and anchor-free algorithm for WSN localization. According to anchor based approach, it is assumed that all reference nodes are anchor nodes whose positions and coordinates are known in advance whereas anchor-free localization algorithms need few anchor nodes where coordinates of these reference nodes are computed automatically.

These algorithms of WSN localization in underground coal mines may face various challenges due to water vapor and coal dust which may degrade the signal and lead to the localization error. Along with this, underground mines have complex structure due to that, a complex network topology require where conventional localization approach may fail to work. In order to deal with this issue, here we present a novel approach for WSN localization for underground coal mining. The main contributions of this work are as follows:

1. First of all, we present distance measurement and signal strength measurement models
2. In the next phase, RSSI based model is used for node localization measurement
3. Finally, a probability density function based improved RSSI model is used to reduce the localization error.