Design And Study On Application Technology Of Air Quality Monitoring System Based On Internet Of Things

Air is a natural resource for the survival of each of us, the air quality is directly related to the sustainable development of human beings. Establishing and improving the system of air quality monitoring in order to make people visually understand the current air quality, has a very important significance for guiding the daily production and life. But China’s current air quality monitoring system still has some shortcomings, for example the monitoring technology is lagging, the monitoring area is small, portable monitoring and permanent monitoring does not match. In a word, the current air quality monitoring system cant satisfy people’s growing demand. So based on the Internet of things technology, embedded technology and Android technology, this paper develops a set of air quality monitoring system, which has two kinds of working modes:stand-alone and network. This system can be used as a portable air quality monitoring equipment and also can be used as a permanent monitoring site, and it can achieve unified management and real-time release of air quality data.The air quality monitoring system mainly consists of two parts, hardware and software systems. The hardware system applies the 32-bit embedded microcontroller STM32 as the control core, selects high precision Sensor and high precision constant potential electrolysis gas sensor based on laser scattering theory to collect the data of PM2.5, PM10 and SO2, CO, O3, NO2. And it uses WIFI module which could work in AP+STA module to complete the communication with the Android App and the remote server. In the aspect of data interaction, we use UDP protocol. In terms of data filtering, the system combines the limiting filtering, inertial filter and other digital filtering algorithm to complete the preliminary analysis and processing of original data, and the hybrid filtering algorithm achieved good results in practical applications.Software system includes three parts:Remote Server, the Android client and the WeChat Official Accounts. We uses the J2EE architecture, mount EJB and Servlet framework in Wildfly application server to complete the unification management of the air quality data and interaction with the Android client and the WeChat Official Accounts for the design of the remote sever. In addition, we build the ArcGIS Server to provide map service for the Android App and the WeChat Official Accounts. The Android App has two modes of stand-alone and network. In Stand-alone mode, the client directly exchange data with the hardware system and complete the display and management of real-time and historical data. Additionally the system adopts the custom file format for storing air quality data, and can achieve high-speed data extraction and parse. In network mode, we transplanted the ArcGIS for Android and panoramaGL widget to achieve map annotation and 3D imaging browsing. In addition, the system uses the big data technology to analyze the daily activities of the user, so as to push the air quality data. The WeChat Official Accounts is convenient for the majority of users to obtain air quality data through a variety of ways. In the WeChat Official Accounts, We transplanted a plug-in named ArcGIS for JavaScript to provide map service. And at the same time Official Accounts support data query, auto reply and other functions.The integration test has shown:The hardware system and software system interact well, each module of the system runs stably and meets the design requirements.