COAL MINE SAFETY INTELLIGENT MONITORING BASED ON WIRELESS SENSOR NETWORK

International Research Journal of Engineering and Technology (IRJET) e-ISSN:2395-0056

Volume: 10 Issue: 05 | May 2023 www.irjet.net

COAL MINE SAFETY INTELLIGENT MONITORING BASED ON WIRELESS SENSOR NETWORK

2,3,4,5

Abstract:

Wireless Sensor Network (WSN) analyses the applicationofthemostrecentWSNtechnologyinwireless monitoring for coal mine safety, focusing on the three essentials. Technology required for subsurface safety monitoringincludetransmissionroutingprotocol,location algorithm, and wireless sensor network (WSN) technologies. The use of wireless sensor networks in intelligent monitoring systems of coal mine safety is suggestedinthisstudy,whichalsoanalysestheprinciples, benefits, and design foundations of wireless sensor networks in these systems. The design scheme and monitoring mechanism of a coal mine safety intelligent monitoring system are presented in light of the current scenario and existing issues with the low degree of intelligence of that system, as well as the viability of wirelesssensor.

Keywords: Arduino, LCD, Gas sensor, Temperature sensor, Node MCU, LoRa, Wireless sensor network.

1. Introduction

Concerning worker safety and health, underground mining operations are a dangerous business. These dangers result from the various methods used to extract the various minerals. The risk increases with the depth of the mine. These safety concerns are quite important, particularly for the coal industry. Therefore, whether mining for coal or any other commodity, worker safety should always be a top priority. Due to ventilation issues and the possibility of a collapse, underground coal mining entailsahigherriskthanopenpitmining.However,safety concernsexistinallformsofminingduetotheuseoflarge equipment and excavation techniques. In opencast and underground mining, modern mines frequently adopt a number of safety processes, worker education and training,andhealthandsafetyrequirements,which result insignificantchangesandimprovements.InIndia,coalhas

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traditionally been the main source of energy, which has greatly aided in the nation's quick industrial growth. Becauseofthis,coalisessentialtotheenergyindustryand accounts for over 70% of all power generation. However, theprocessalsocreatesadditionalbyproducts,whichpose a possible risk to the environment and the nearby population. Instead, this study makes a sincere effort to assess the seriousness and create a real-time monitoring systemofdetectionbyusingLORAtechnology.

1.1 Contribution of the Work

The environment around mining frequently contains covert threats like poisonous gases that can expose those whowork theretoserioushealthrisks.Fortheprotection of the miners, these gases must occasionally be identified, and the dangerous condition must be promptly alerted. Although wired network monitoring solutions have made a substantial contribution to mine safety, not all mining environments are ideal for them. A real-time monitoring system might aid in keeping an eye on and managing the mining environment. The majority of the benefits offered by Lora technology make it appropriate for real-time monitoring systems. As a result, it was agreed that the main goal of this project would be to create an effective real-time monitoring system that would enable the identification of various mine gas leaks as they occurred and the development of appropriate preventative measures.

1.2 Related works

There are several existing methods of wireless sensor network-based coal mine safety intelligent monitoring usingArduino.

(i) A suggested design that is based on the MSP430, There are difficult circumstances in the coal mine nowadays owing to global warming and climatic changes. Atomization in the coal mining industry is undoubtedly

required tolower costs,increase production,and enhance the quality of the final product. This will also lessen the workload on the mine workers. In order to monitor the temperature, humidity, gas levels, and smoke status in an underground mine, this article suggests a concept for a wireless sensor network (WSN) using an MSP430xx controller. In accordance with the current climate in the mine field, this system also regulates the ventilation need for mine employees. The MSP430 microprocessor, a temperature sensor, and other low-cost components are usedinthissystem.

(ii) Using a Zigbee wireless sensor network, a monitoring system for coal mine safety. The monitoring system gathers underground coal mine temperature, humidity, and methane readings using Zigbee sensor nodeslocatedthroughoutthemine,andthentransfersthe data to an ARM-based information processing terminal. TheterminalusesEthernettotransmitdatatotheground, where the monitoring Centre analyses it and makes it available to the LAN for remote users to access. The system may SMS connected safety workers if the data is over its limit. The real-time monitoring of the working surfaceisnowpossiblethankstothistechnology.

(iii) Health monitoring systems have recently gained popularityandsignificanceasastudyarea.Foravarietyof uses, including the military, home health care, hospitals, sports training, and emergency monitoring systems, research on health monitoring has been undertaken. In this study, a programmable system on chip (PSoC)-based portable real-time wireless health monitoring system is created. The created acquisition system is used to remotely monitor a patient's temperature, heart rate, and blood oxygen saturation using pulse oximetry, blood pH, andanelectrocardiogram.Byusingawirelessmodule,this technologyenablesthedoctortocomprehendthepatient's circumstance on the computer screen. Here, cheap costs, minimal power usage, and adaptable network structure Remote patient data is sensed using a ZigBee wireless module.We'llbeusingthePSoCdesignertool.

2. Proposed Model:

Thetransmittersideisthepartofthesystemthatmatters the most. All measurements performed should be the responsibility of this component. The measuring node need to have a wide variety of sensors that can monitor thingsliketemperatureandgaslevelsandreturndata.

Thisstationwillincludetherequisitehardware(awireless module and a microcontroller, interfaced to a laptop

computer) and software to execute the necessary processing, displaying, and storing of values. These values should then be communicated over a wireless link to the datacollectionstation.

The core of this project, without which it would be impossible to create the intended system, is the collection of various sensors. Sensors get input from the environmental circumstances. With the help of signaling design, the temperature (FU1.1) and gas sensors were developed from the ground up. The individual signal processing circuits for each sensor will be connected to them. In orderto getthedesired outputfrom the sensors, these circuits will create the essential circumstances. The microcontroller must sample the signals and values that come from these sensors. The central processor or controllerofthemeasuringnodeisthismicrocontroller.

Theoperation ofother functional unitsisgovernedby the valuesthatareinputtoandoutputbythemicrocontroller. Totransferthesensordatatothedatacollectingstation,a wireless module (FU1.9) will be interfaced with the microcontroller. The wireless LORA protocol will be utilized by this module. According to the past and current data collected from the measurement node, this module will offer the scheme. In a database format, the results of thetestingshouldalsobekept.A databaseshouldcontain recordsofthemeasuredvalues.

TRANSMITTER SIDE:

RECEIVER SIDE:

 ESP32 Controller: ESP32 is a low-cost SystemonChip(SoC)Microcontrollerfrom Espress if Systems, the developers of the famousESP8266SoC.

 Li-ion Battery: Lithium-ion (Li-ion) batteries have become the predominant energy storage means for off-grid solar products due to their high efficiency, low cost, high capacity, lack of memory effect, andlongcyclelife

 Gas sensor: Ideal sensor can be utilized to locate the risk of LPG spill in your automobile or in a provider station, garage tankcondition.

 Temperature sensor: This is the sensor which is used to measure the ambient air temperatureinsidethemine.

 LORA: LORA is a Long-Range conversation module,whichcanbeusedforlongvariety up to two KM based totally on serial Communication

 Node MCU: Node MCU is an open source IoT platform. Which includes firmware which runs on the ESP8266 Wi-Fi Module from Espress if Systems, and hardware whichisbasedontheESP-12module.

 LCD: The liquid crystals can be manipulated through an applied electric voltagesothatlightisallowedtopassoris blocked

Overall, the system monitors the condition inside the mines and inform the miners incase of emergency and detect the hazardous gases, check the temperature to examine the survival of coal miners in the underground andtoalerttheminersincaseofemergency.

2.1 ESP32 CONTROLLER:

For those just getting started in the world of embedded systems and microcontrollers, Arduino is a fantastic platform. You may create a number of projects that are eitherforfunorareevenforsaleusingalotofinexpensive sensors and modules. New project concepts and implementations emerged as technology developed, and the Internet of Things, or IoT, is one such notion. It is a platform that is connected to the internet so that various "things"orgadgetsmayexchangeinformation

SpecificationsofESP32

ESP32 has a lot more features than ESP8266 and it is difficult to include all the specifications in this Getting Started with ESP32 guide. So, I made a list of some of the important specifications of ESP32 here. But for complete set of specifications, I strongly suggest you to refer to the Datasheet.

 Single or Dual-Core 32-bit LX6 Microprocessor withclockfrequencyupto240MHz.

 520KBofSRAM,448KBofROMand16KBofRTC SRAM.

 Supports 802.11 b/g/n Wi-Fi connectivity with speedsupto150Mbps.

 Support for both Classic Bluetooth v4.2 and BLE specifications.

 34ProgrammableGPIOs.

 Up to 18 channels of 12-bit SAR ADC and 2 channelsof8-bitDAC

 Serial Connectivityinclude 4xSPI,2xI2C,2xI2S, 3xUART.

 Ethernet MAC for physical LAN Communication (requiresexternalPHY).

 1 Host controller for SD/SDIO/MMC and 1 Slave controllerforSDIO/SPI.

 MotorPWMandupto16-channelsofLEDPWM.

 SecureBootandFlashEncryption.

 Cryptographic Hardware Acceleration for AES, Hash(SHA-2),RSA,ECCandRNG.

2.2 Gas Sensor:

TheMQ-2gassensor'ssensitivecomponentisSnO2,which hasareducedconductivityincleanair.Theconductivityof the sensor increases as the concentration of the target flammable gas rises. Please utilize a straightforward electro circuit to translate changes in conductivity into a signalthatcorrespondstogasconcentration.TheMQ-2gas sensor is affordable, versatile, and very sensitive to LPG, Propane, and Hydrogen as well as to Methane and other flammablegases.

FEATURE:

 Goodsensitivitytocombustiblegasinwiderange

 HighsensitivitytoLPG.

 Longlifeandlowcost.

APPLICATION:

 Domesticgasleakagedetector.

 Industrialcombustiblegasdetector.

 Portablegasdetector.

This sensor is used to gauge the temperature of the surrounding air inside the mine. Using a load-balanced thermistor circuit, this sensor was constructed according tofirstprinciples.Betweentheappliedresistor(load)and the thermistor, this circuit divides the voltage. A thermistor is a variable resistor with a temperature dependence.Despitethefactthatallresistorsaresensitive to temperature fluctuations, thermistors are particularly so because of the substance they are made of. This substance has a particular resistance. For that substance, this resistance is a constant. Figure depicts the temperaturesensorcircuit.

Temperature sensor circuit schematic:

At 25 C, the thermistor's resistance is 2000 ohms. The method of calibration and measurement from this sensor will be described in detail before the selection of the load resistor value is justified. It was calibrated using the 3Point system. This entails determining the thermistor's resistance at 3 different temperatures. The following values were discovered after solving for the thermistors' characteristicconstantskaD1:692103kbD1:896104kc D4:602107.

NodeMCU with ESPlorer IDE:

Lua scripts are generally used to code the NodeMCU. Lua is an open source, lightweight, embeddable scripting language built on top of C programminglanguage.

NodeMCU with Arduino IDE:

HereisanotherwayofdevelopingNodeMCUwitha well-known IDE i.e. Arduino IDE. We can also develop applications on NodeMCU using Arduino development environment. This makes easy for Arduino developers than learning new language andIDEforNodeMCU.

Difference in using ESPlorer and Arduino IDE:

 We may state that while building applications for NodeMCU using the ESPlorer and Arduino IDEs, there is a difference in the programming languages used.

 If we use the Arduino IDE to create NodeMCU programmers, we must code in C++, and if we use the ESPlorer IDE, we mustcodeinLua.

2.4 Node MCU:

The ESP8266 Wi-Fi chip is used by the open source NodeMCU LUA-based firmware. NodeMCU firmware includesESP8266 DevelopmentBoard/Kit (alsoknownas NodeMCU Development Board) in order to explore the capabilityoftheESP8266chip.

 NodeMCU can readily grasp Lua script because it is essentially a Lua interpreter. Sequential Lua script execution occurs when we build Lua scripts for NodeMCU and submit or upload them to NodeMCU. NodeMCU will not be able to binary firmware file as a result. It will submit the complete Lua script to NodeMCU for execution.

 LoRa(LongRange)isawirelesstechnologythatoffers long-range, low power, and secure data transmission for M2M (Machine to Machine) and IoT applications. LoRaisaspreadspectrummodulationtechnologythat is derived from chirp spread spectrum (CSS) technology. LoRa can be used to connect sensors, gateways,machines,devices,etc.wirelessly.

 A business called Semtech launched LoRa. LoRa Technologies operates in many frequency bands in various nations. For example, it uses the 915 MHz band in the USA, the 868 MHz band in Europe, and the 865 to 867 MHz and 920 to 923 MHzbandsinAsia.

 LoRa's operation resembles cellular communication more. The block diagram for LoRacommunicationisprovidedbelow.Through a LoRa Gateway, the signal from one LoRa Node reaches another Node. Application server connects to the LoRa Gateway to receive the signal,whichthenetworkserverthenprovidesto theenduser.

 The business SemTech created and trademarked the LoRa technology. Large cells and a variety of application areas, which LoRa is known for, can allow an extraordinarily high density of devices tocoexistinasinglecell.Ithasanadjustabledata rate, extensive communication coverage, and strong resistance to multipath fading. Its uses rangefromagriculturetomedicine.

 Using LoRa modulation, the MAC layer protocol known as Lora WAN was created. This software governs the timing of message transmission and reception on LoRa devices. This works well for transmitting sparse sensor data over a long distance. Consequently, it is more affordable and has a wider coverage area than its rival wireless communication systems (WIFI, Bluetooth, and Zigbee). With deepindoorpenetration andultralow power consumption, Lora WAN is accessible indoors and uses licence-free spectrum. It also offers end-to-end security for each node in the network and facilitates roaming by allowing for seamlesshandoverfromonenetworktoanother.

 Depending on the end devices communicating and the form of communication being used, a specific number of elements must be taken into account. Vehicle to vehicle, cloud to cloud, infrastructure to infrastructure, network to network, and vehicle to grid are just a few examples of the several forms of vehicular communication that can occur depending on the end nodes. The current protocol used in vehicleto-vehicle communication, DSRC (Dedicated Short-Range Communications), works at a frequency of 5.9 GHz and notifies drivers of impending collisions and exchanges data. Spreading factor, signal bandwidth, carrier frequency,andothervariablesallhaveanimpact on the transmissions when this type of connectionismadeutilizingLoRatechnology.

THIKSPEAK:

 In this report, we go through how to utilize ThingSpeak, a "Internet of Things" (IoT) "Application Programming Interface" (API) and online service. The ability to identify and communicatewithbasicitemsordevicesoverthe Internet is what we refer to here, despite the fact that the definition of what should be defined underthewordisevolvingovertime.

 The ThingSpeak API is an open-source interface that listens to incoming data, timestamps it, and publishesitforbothhuman users(throughvisual graphs) and computers (via readily parse-able code).

 We examine real-world applications for the Arduino microcontroller as well as interaction with graphical operating systems using a Python script. According to our findings, ThingSpeak is particularly helpful for smaller hardware projects that need Internet access but can't afford to maintain a dedicated communication server. There are other IoT services available, but they frequently charge for some of their features and arenot,therefore,opensource.

2.5 IMPLEMENTATION

 TheESP32Microcontroller acts asthebrain ofthesystem.

 LORAisusedtoconnectthetransmitterand receiver.

 TheMQ6gassensordetectstoxicgasessuch asCO2,butane,benzene,andLPG.

 The LM35 temperature sensor detects surrounding temperatures and body temperatures.

 MAX30100 senses the oxygen level and heartrateofminers.

 A panic button can be used, which sends an alert to the control room wheneveraworkerneedsmedicalattention.

 An ESP32 is a microcontroller that provides a highly integrated Wi-Fisolution andisusedtofetchoruploaddata.

 The live data streams are monitored and analyzed with graphical representation usingThingspeak.

 A 16x2 LCD is used to display the output of theData.

 A buzzer gives an alert to authorized personnel regarding the detectedhazardous event.

3.5 Experimental Results and Discussion

 The outcomes of the suggested system are covered in this chapter. It demonstrates that several sensors were used to monitor various parameters, including body and ambient temperature, oxygen saturation, heart rate, and gas level, on a regular basis. We use ESP8266 to save data in the cloud. The values may be displayed on the cloud and we can examine the data thanks to the creation of the Thingspeak channel. Real-time data streams may be aggregated, visualised, and analysed using Thingspeak's cloud-based platform. Thingspeak immediately visualises the data that is uploaded byoursensors.RunThingspeakMATLABcodeto analysesthedataanddoliveanalysis.Thevalues may be displayed on the cloud and we can examine the data thanks to the creation of the Thingspeakchannel.

 Thinkspeakisusedtodownloaddataasanexcel file, which is then saved as a record for future use. A warning message and alert sound are transmitted to the control area if the value is abnormalandgasisdiscovered.

Conclusion

Consequently, a comprehensive mine safety system was createdfromthegrounduptoguaranteetheprotectionof miners.Thiswholesystemwascreatedtobebothportable and modular, combining mechanical, electrical, and specialized software to provide a strong and adaptable system that would best meet the demands of the mining environment.

Thedevicealsohascutting-edgetechnologythatenablesit to precisely measure a variety of ambient parameters within the underground area. The inclusion of temperature,humidity,vibration,anddustsensors,eachof which provides exact readings and improves the system's overallaccuracy,makesthisfeasible.

Additionally, the LORA communication protocol is used in this system to facilitate communication and data transmissionbetweentwonodes.

Thanks to such technical improvements, miners can be confident that they are working in a secure environment that is carefully supervised and controlled, which makes theirminingexperiencebothefficientandsafe.

References

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