Design And Implementation Of Cold Chain Logistics Monitoring System Based On Temperature And Humidity Exception Handling And NB-IoT

With the improvement of China's national consumption level,the demand and quality of all kinds of cold chain distribution products are increasing year by year.However,the small proportion of cold chain logistics system,uncontrollable transportation links and scattered information make it difficult for cold chain logistics to achieve effective supervision.In order to protect people's health,it is necessary to establish an effective monitoring mechanism in all aspects of cold chain transportation.Based on a lot of investigation and research,this paper finds that there are two main problems in the current cold chain logistics monitoring system:first,in the abnormal temperature and humidity detection link,the temperature and humidity data may produce concept drift and affect the detection accuracy;Secondly,the passive tags and active tags used in the current mainstream cold chain logistics monitoring system have some problems,such as insufficient perception ability,unable to mass connect and real-time monitoring,unable to build a unified information monitoring platform and so on.In the process of data transmission,the security of the cold chain logistics system is reduced.Firstly,in order to solve the concept drift problem in cold chain logistics monitoring system,this paper proposes a temperature and humidity data anomaly detection algorithm based on long-term memory neural network LSTM and double sliding window.Firstly,the LSTM network model is used to predict the temperature and humidity data,and the prediction accuracy is calculated.Then,the double-layer sliding window mechanism is used to detect the concept drift of the data,and the data that may cause the concept drift is deleted.Finally,according to the probability density of the difference in the current distribution to calculate the abnormal possibility of temperature and humidity data.The model can update the model dynamically,adapt to the concept drift,and solve the problem of data concept drift effectively.Secondly,with NB-IoT technology as the link,SCM STM32 as the core of logistics vehicle management device,a cold chain logistics monitoring system based on NB-IoT is designed and implemented by using the cloud platform of Internet of things,web and smart phone app,so as to build a unified information platform.It is divided into data acquisition controller subsystem supporting NB-IoT,logistics vehicle management application subsystem and data monitoring subsystem.The data acquisition controller subsystem takes STM32F103RBT6 as the core,uses the temperature and humidity sensor in the car,GPS global positioning system and intelligent door lock module to establish the sensor module,and remotely transmits the obtained information with the logistics vehicle management application system through NB-IoT communication module bc35-g.The vehicle management application subsystem adopts the technology of Telecom cloud and onenet cloud platform,which is responsible for managing a large number of data acquisition controllers and transmitting information to the data monitoring subsystem to realize the logistics vehicle management function.The data monitoring subsystem integrates the functions of data acquisition and control system and vehicle management application in the monitoring website and smart phone app through informatization,and establishes a unified platform for centralized monitoring of various information of cold chain logistics vehicles.On this basis,the functions of temperature and humidity anomaly detection and early warning,intelligent unlocking and risk assessment are realized.Finally,all aspects of the cold chain logistics system based on temperature and humidity anomaly detection and NB-IoT are tested,and the test results meet the expected requirements.The cold chain logistics system based on NB-IoT of abnormal temperature and humidity detection studied in this paper can realize the function of early warning and unified information monitoring of abnormal temperature and humidity of logistics vehicles,and promote the further development of cold chain logistics industry.