Research On The Air Quality Monitoring System Based On Wireless Sensor Network

The situation of the air pollution of China is getting worse in recent years. Timely andaccurate discovery of the air pollution is the key to solving the problem. The traditionalautomation equipment for the air quality monitoring system is expensive. It also needs harshworking conditions. The equipment can’t work with low-cost, real-time, flexible in the keymonitoring areas.In response to this reality, this dissertation introduces sensors, wireless communications,wireless sensor networks and other related technologies, does an in-depth study of the airquality monitoring system and proposes a solution which is the air quality monitoring systembased on wireless sensor networks(WSN). The dissertation starts from two aspects inhardware and software of the monitoring system. On the hardware side, it chooses gas sensorsof Switzerland Membrapor, STM32microcontroller of STMicroelectronics, short-rangewireless communications chips CC2530of TI, long-distance wireless communication moduleGPRS DTU of Beijing Zhen Hongwei as the main structural unit of the node and the gatewaynode by comparing and analyzing. All the nodes are powered by batteries. Meanwhile thisthesis designs a more reasonable gas sensor conditioning circuit. In terms of software, theworkflows of nodes are optimally designed. Because in different application areas, the WSNstructures are not exactly same, and the air quality monitoring system based on WSN has tofocus on how to extend the lifetime of the networks. So this thesis does the exploitation of theCompressed Sensing(CS), and combines this technology with the monitoring system forprocessing data transmission in order to achieve further reduce system power consumption.On the basis of CS study, the thesis introduces the Distributed Compressed Sensing(DCS)which has a great advantage in the signal group processing. Meanwhile this thesis analyzesthe energy consumption model of nodes in order to do the preparation of the softwaresimulation of energy consumption. From the perspective of the simulation, using MATLABsoftware, it verifies the feasibility of the two algorithms that are applied on the datatransmission of the air quality monitoring system based on WSN.The simulation results can get the conclusion of the superiority of the CS/DCS, whichcombine with the data transmission of the air quality monitoring system based WSN. Andwithout affecting the normal work conditions, DCS can greatly extend the life of the system.