Development Of Pedestrian Radiation Monitoring IoT System

Pedestrian radioactivity monitoring Internet of Things system is a system that can be applied to important places such as airports,stations,customs,large-scale events and venues,hospitals,military departments,and nuclear power plants for the detection,measurement and alarm of pedestrians carrying radioactive materials.This article is based on the nuclear radiation detection project "Pedestrian Concierge Gamma Spectrum Detection System" developed by Beijing Zhongke Kunrun Technology Co.,Ltd.This article focuses on the design and analysis methods of the system,including nuclear pulse acquisition circuit design,digital Spectrometer analysis,embedded MCU control block design,host computer and embedded software development,Io T server construction,alarm and identification algorithm analysis.During the development of the system,the specific work is as follows:1.Through the school library,China How Net platform,Wanfang database and other ways,consulted the development process of nuclear technology and related professional knowledge,understood the detection principle of radioactive detection technology;consulted the research and development and development of nuclear monitoring instruments The current situation,as well as key principles and technologies.2.Completed the design of the overall system framework.3.Completed the principle of system hardware circuits such as pre-core pulse acquisition circuit,high-speed operational amplifier and high-speed ADC combined with FPGA to realize the hardware circuit part of ? spectrometer,digital energy spectrum circuit,embedded MCU control board circuit,Wi Fi communication circuit,etc.Graph design,PCB design,circuit debugging,embedded low-level software writing,etc.4.In the FPGA digital energy spectrometer,a Mexican straw hat wavelet shaping algorithm and wavelet analysis method are used to filter and shape the ? energy spectrum and derive and calculate the all-energy peak position,net peak area and peak half-height width.5.Completion of energy spectrum data collection,deduction of rapid alarmrecognition algorithm and realization of programming language,real-time analysis and fast abnormal perception of every second data from energy spectrometer.6.Completed the construction of Internet of Things server,database construction and data access.7.The functional measurement of the developed system was carried out,including pulse signal acquisition circuit,FPGA digital energy spectrometer communication data and external communication of the alarm terminal,alarm test and false alarm rate.The core technology of the system is as follows:1.As of the 1990 s,gamma spectrometers were still mainly in analog form.With the high speed of ADCs,the emergence of ADCs and FPGAs with hundreds of megasamples,gamma spectrometers began to appear in digital form.The system uses the high-speed operational amplifier,high-speed ADC and FPGA to realize the hardware circuit part of the gamma spectrometer.2.In the digital ? energy spectrometer,the filtering of the energy spectrum has become the top priority.Generally,a signal processing unit dedicated to FPGA design can be used to convert the exponential pulse waveform into trapezoidal,triangular,Gaussian,or Mexican straw hat signals.In this way,the signal noise can be reduced to the greatest extent,the signal-to-noise ratio can be improved,the pulse accumulation can be eliminated,and the baseline can be eliminated,which is beneficial to the exponential pulse parameter identification and the nuclide identification.The system uses the Mexican straw hat wavelet shaping algorithm and wavelet analysis method to filter the ? energy spectrum and to derive and calculate the all-energy peak position,net peak area and peak half-height width.3.This system combines the nuclear detection technology with the Internet of Things technology closely.The post-stage uses the ARM single-chip microcomputer as the CPU.Its function is to process and analyze the data from the gamma spectrometer,the driving and control of the sound and light alarm,WIFI and GPRS Internet of Things communication module drive and control,lithium battery charging and other peripheral management;the Internet of Things server uses Alibaba Cloud Linux system server to build a My SQL database and back-end management system to achieve cloud synchronization and management of monitoring data and alarm messages.4.The PC terminal uses the most popular QT development platform to develop? spectrum analysis software suitable for windows environment,which can quickly,clearly and accurately analyze the ? spectrum data from this measurement system..