Implementation Of Dust Monitoring And Early Warning Device Based On LoRa

With the development of the economy,dust concentration has become a popular topic,attracts more attention than before.Meanwhile,dust pollution has also become more serious.High dust loading induces a variety of occupational lung diseases currently,especially in the colliery,which poses a severe threat to the workers’ health.To monitor the dust concentration in real-time,to achieve long-distance,strong anti-interference communication ability,and a high level of intelligence,this essay researches and designs a dust monitoring and forewarning device based on LoRa(Long Range).The system is mainly composed of three parts:Data Acquisition module,Data Transmission module,and Intelligent Host.(1)The Data Acquisition module completes the software and hardware design of the dust concentration detection module.At the same time,temperature and humidity detection are supported as well.The data terminal consists of a sensor module,a microprocessor module,a GSM(Global System for Mobile Communications)module,an LCD(Liquid Crystal Display)module,and a power supply module.Dust concentration collection in data terminal uses GP2Y1014AU sensor and for temperature and humidity collection,SHT35 is applied.Data transmission and register configuration are set through a GPIO port and a microprocessor that uses STM32F407Z from the STM company.For the main control chip,STM32F407ZGT6 is selected,which has low power consumption and supports IIC communication.SIM800C GSM module,which possesses stable performance,large power supply input range,and built-in TTL serial port,connecting to the microprocessor through serial port3.When the dust concentration is greater than the warning threshold,the alarm message is sent to the mobile phone for ensuring the safety of the field.And the LCD module displays the figure of dust concentration,temperature,and humidity of the monitored area in real-time.(2)The Data Transmission module fulfills the design of the software and hardware of the LoRa terminal.The LoRa terminal sends the information collected by the data terminal to the Intelligent Host.Meantime,its low-power star network structure design drove by the comparison of pros and cons of the networking and features of LoRa wireless transmission.This module uses the SX1278 chip and Chirp spectrum enhance technology is implemented to modulate the information into a LoRa radio frequency signal.The SX1278 chip is a low-IF transceiver with the half-duplex transmission mode,low power consumption,long transmission distance,and strong anti-interference communication ability,satisfying the research demands.The LoRa module receives data through SPI(Serial Peripheral Interface)protocol and sends to the LoRa receiver.Then,the LoRa receiver uploads the data to the Intelligence Host orderly according to the module number through the USB to TTL serial port line.The USB to TTL serial port module converts the RS232 voltage level output by the LoRa terminal into TTL level to communicate with the host computer.(3)The Intelligent Host constructs the system platform and the prediction model which is based on the LSTM(Long Short Term Memory)cyclic neural network.The software design of the monitoring center uses the Visual Studio 2013 development tool to design GUI(Graphical User Interface)to display the data collected by the sensor in real-time.When the dust concentration level reaches the preset warning threshold,an alarm is sent immediately.The Access database process and store the collected data for querying conveniently.The LSTM-based cyclic neural network is trained by the measured data,comparing the historical data like PM2.5,PM 10,temperature,and humidity records to predict.Meanwhile,the Adam optimizer is employed to optimize the prediction accuracy.Finally,model tests and simulations are performed and compare with the simulation results of the vector machine prediction model,the deviation is evaluated.