Research On Environmental Monitoring System In Transport Container Of Agricultural Products

Our country is the largest producer of agricultural products.With the economic development and people's living standards improving,people's demand for agricultural products is not limited to the number,paying more attention to quality.Cold chain logistics solve the season and geographical restrictions of agricultural products,reduce losses and the quality declined of agricultural products during transport.Agricultural transporter is one of the important agricultural produce cold chain logistics carrier.In the support of Tianjin Food Safety&Low Carbon Manufacturing Collaborative Innovation Center and the National Science&Technology support program "Car microenvironment information perception and intelligent control device",this paper presents a study of transport container environmental monitoring system,to monitor location information and environmental parameters in container.The system can detect the temperature,humidity and wind speed,display,transmission and storage the data on line and real-time.A model base on gray theory and radial basis function predicts temperature and humidity changes.Put the forecast results into statistical process control charts,it can determine which state model the change trend in.Adaptive fuzzy PID control algorithm is used to do the temperature regulation,and use MATLAB simulation to analysis the control effect.The system contain ARM embedded system core,using the Linux operating system,and incorporating the temperature,humidity and wind speed sensor networks,GPS global positioning function module,3G wireless transmission module,Qt monitoring interface,so it can monitor the environmental parameters in container the whole process.The main content of the paper include the following aspects:1)Describes the current situation of cold chain logistics and transporter of agricultural products,analyzes the development trend of agricultural products transport car environmental monitoring technologies and systems,makes a brief introduction on developments and trends in domestic and foreign agricultural transporter.2)The overall design of the system software architecture and multithreaded program flow,including sensor bus network and communication protocols,GPS positioning and 3G transmission software processes.Transplant the Linux system into ARM development board,then design the Qt real-time monitoring system interface to achieve data integration monitoring.3)A forecasting model based on gray theory and RBF neural network was proposed to predict the temperature and humidity inside the container.A alarm model based on statistical process control theory judgments defined three different models,the alarm improved the accuracy with respect to a fixed threshold alarm method.4)Based on PID control and fuzzy control theory,adaptive fuzzy PID algorithm was used to control temperature.An adaptive fuzzy PID controller was test through the MATLAB simulation,results showed it had a better effectiveness relative to conventional PID controller.