Development Of An Automatic Weather Station Fault Detector Based On Embedded Syste

As the mainstream surface meteorological observation equipment,automatic weather stations can automatically collect,process,store and transmit various meteorological elements,and play an important role in the comprehensive meteorological observation system.Therefore,ensuring that the automatic weather station is in a normal working state plays a decisive role in the quality of meteorological data.This paper analyzes the reasons for the failure of automatic weather stations,and designs and implements a fault detection instrument for automatic weather stations in view of the cumbersome operation and low accuracy of fault detection in current automatic weather stations.The instrument includes a fault expert system and an on-site fault detection system,which can quickly locate the fault point of an automatic weather station.The main research contents are as follows:(1)The structural design and working principle of each channel of different types of weather stations are analyzed,and the electrical signal parameters,types,error range,measurement range and conversion relationship corresponding to each meteorological element are pointed out.The performance indexes and main functions of the automatic weather station fault detection instrument are clarified,which lays a theoretical foundation for the development of the whole fault detection system.(2)A automatic weather station fault expert system based on belief rule base(BRB)is established.Aiming at the complex nonlinear relationship between the fault level of the sensor and the actual data of the sensor in the weather station,a fault expert system of the automatic weather station based on the belief rule base is established by using the qualitative and quantitative relationship between them.Compared with the method based only on expert experience knowledge,the system optimizes the traditional expert experience library,and the model test results are accurate and interpretable.(3)Aiming at the failure causes of automatic weather stations,combined with the measurement principle of meteorological signals,an on-site fault detection instrument for automatic weather stations is developed.The instrument adopts the hardware structure of lower computer and host computer.The lower computer takes STM32F103ZET6 as the main control chip,and takes the meteorological signal acquisition and analog circuit as the core to realize the control of the physical circuit,the logical calculation between the meteorological quantity and the electrical signal;at the same time,the improved four-wire resistance signal output circuit is used,and the combined with methods such as optocoupler isolation,USB-serial communication conversion and software compensation,the mutual interference between each channel can be effectively reduced,thereby improving the accuracy of signal acquisition and simulation.As the carrier of the upper computer of the detection system,the industrial computer is equipped with the on-site fault detection software of the weather station,which mainly completes the functions of sending control commands and displaying the detection results.(4)The embedded software of lower computer and the running control software of the upper computer are developed.Lower computer software includes chip port configuration driver and logic operation code;the upper computer software realizes the function of data processing,display and control of the lower computer.The experimental test results show that the fault detection instrument developed in this paper can not only distinguish the fault level of the meteorological sensor,accurately collect the meteorological signal actually input by the automatic weather station,and quickly locate the fault location of the sensor;it can also simulate and generate the required meteorological signal according to the user’s needs,so as to quickly judge the working status of the collector and improve the efficiency of inspection and maintenance.