Development Of Real-time Monitoring System For The PM2.5 Concentration Based On Quad-rotor Unmanned Aerial Vehicles

In recent years,the haze weather is seriously increasing in China.The community and government departments have pay much attention to haze pollution.As the main factor of haze,many scholars have carried out extensive researches for PM2.5.However,the research that refers to real-time monitoring and spatial vertical distribution is not much for PM2.5 concentration in air.The main difficulty is to obtain a wide range of PM2.5 concentration data in high air altitude.This thesis designs a PM2.5 real-time monitoring system based on four-rotor UAV(Unmanned Aerial Vehicles).The system which is equipped with module of PM2.5 sensor and can be run monitoring over-the-air.The monitoring module can send air data back to the ground by wireless transmission system in time,saving and processing data at the same time.The content of the thesis includes 4 parts and described as follows.(1)The UAV platform is researched and set-up.Compared to fixed wing aircraft,Multi-rotor UAV has the advantages of simple structure,stable flight,better hovering ability and so on.Besides,with the functions of multi-rotor UAV such as vertical takeoff and hovering accurately,it is exactly suitable for some researches of atmospheric environment for high altitude.This paper has designed and made a platform based on four-rotor UAV,its carrying capacity is 2 kilograms.This thesis selected Pixhawk as the aircraft control system that is an international open source flight control system because the aircraft flight control system is very complex.Stable and reliable UAV platform is an important prerequisite for the successful operation of the system,finished the UAV platform after a lot of debugging work.(2)Wireless monitoring module is researched and developed.The wireless monitoring module includes an airborne transmitter module and a ground receiving module.The airborne transmitter module includes PM2.5 sensor,STM32 development board and wireless transmission module transmitter.The PM2.5 sensor and the wireless transmitter are integrated on the STM32 development board by developing communication protocol.Ground receiving module includes SD memory card,wireless transmission module receiver,STM32 development board.The SD memory card and receiver of wireless transmission module were integrated on STM32 development board by the developing communication protocols.(3)The PC-side data monitoring platform is researched and developed.The transmitter of the wireless transmission module transmits the monitored data to the ground.After receiving the data,the receiver sends the data to the PC-side data monitoring platform through the serial port,and show the PM2.5 concentration on the computer in real-time.The ground data monitoring software on PC side is programmed by C#,select the VisualStudio2012 as development environment.(4)The application for system is researched.With the monitoring system to study the distribution of PM2.5 concentration in some areas of Xiasha,Hangzhou.Five experimental sites were selected for monitoring and data collection,according to the standard for homogeneity,representative and safety.The experiment showed that this system can run real-time monitoring and collect data for PM2.5 in air.Besides,PM2.5 concentration fluctuated with different times in the same place.In five experiments,the PM2.5 concentrations increase with the altitude increase gradually.The study demonstrates the feasibility of UAV with mobile monitoring devices as an effective and flexible means to collect three-dimensional air pollutant concentration data,particularly for monitoring the vertical profile of air pollutants.