Research and Design of Distributed IoT Water Environment Monitoring System Based on LoRa

Abstract

In order to solve the problems of high labor cost, long detection period, and low degree of information in current water environment monitoring, this paper proposes a lake water environment monitoring system based on LoRa and Internet of Things technology. The system realizes remote collection, data storage, dynamic monitoring, and pollution alarm for the distributed deployment of multisensor node information (water temperature, pH, turbidity, conductivity, and other water quality parameters). Moreover, the system uses STM32L151C8T6 microprocessor and multiple types of water quality sensors to collect water quality parameters in real time, and the data is packaged and sent to the LoRa gateway remotely by LoRa technology. Then, the gateway completes the bridging of LoRa link to IP link and forwards the water quality information to the Alibaba Cloud server. Finally, end users can realize the water quality control of monitored water area by monitoring management platform. The experimental results show that the system has a good performance in terms of real-time data acquisition accuracy, data transmission reliability, and pollution alarm success rate. The average relative errors of water temperature, pH, turbidity, and conductivity are 0.31%, 0.28%, 3.96%, and 0.71%, respectively. In addition, the signal reception strength of the system within 2 km is better than -81 dBm, and the average packet loss rate is only 94%. In short, the system’s high accuracy, high reliability, and long distance characteristics meet the needs of large area water quality monitoring.

Evaluation of LoRa Network Performance for Water Quality Monitoring Systems

“…Although, the trend of packet loss from station 2 had a high loss compared to the other stations, the packet loss rates were still within acceptable ranges for low packet data. A previous study by Wei et al concluded that an increase in communication distance increases the packet loss rate [37].…”

“…Furthermore, the spread value of the RSSI was affected by distance, urban environmental influences, weather, interruption of other radio frequencies, and other variables. It can be concluded that the RSSI value of LoRa decreases as the distance increases with the effect of NLOS [37]. In addition, the higher gain of the antenna strengthens the received signal while reducing interference during transmission.…”

Research on Intelligent Monitoring of Urban Environment under the Environment of the Internet of Things

“…Among them, data reading and recording need to be collected manually, and data statistics and data comparison rely on computer systems, which are completed through databases and data calculation modules. The urban environment intelligent monitoring method and system under the Internet of Things environment designed in this paper need to fully cover the existing environmental monitoring business, replace manual work with Internet of Things equipment, and establish a data acquisition, storage, and analysis system for mass monitoring data [2].…”

Water Quality Sampling and Multi-Parameter Monitoring System Based on Multi-Rotor UAV Implementation

“…In addition, common methods of water quality monitoring include the establishment of water quality monitoring stations in water bodies [15,16] and the installation of wireless water quality monitoring sensors [17] that enable continuous monitoring of the water quality. Water quality data are transmitted, stored, and accessed online through wireless communication [18].…”