Research On Metal Crack Detection Technology Based On Phase Feature Of RFID Reflected Signal

In recent years,the industry in our country is developing rapidly,and the structural safety of industrial plants has attracted more and more attention.The metal structure of industrial plants has long been affected by the vibration effect of industrial production equipment,which can easily cause fatigue damage to the metal structure of the plant.If the damage to the loadbearing structure of an industrial plant cannot be detected early and dealt with in time,as the degree of damage deepens,the structural failure will become more serious,which may cause unpredictable and unexpected consequences.Therefore,it is particularly important to monitor the health of the metal structure of an industrial plant.In the field of structural condition monitoring,RFID has gradually developed into a research direction of structural condition monitoring with application potential.Based on the application of RFID in the field of structural condition monitoring,this paper studies the crack detection of metal structures in industrial plants,designs a metal crack sensor tag based on the microstrip antenna structure,and proposes an RFID backscatter signal phase Characteristic crack detection method for metal structures.The research work of this paper can be summarized as follows:(1)Discusses the impact of the metal environment on the RFID system and solutions.Based on the microstrip antenna structure,a metal crack sensing tag that can be used for metal structure crack detection in industrial buildings is designed.By optimizing the radiation surface structure,the tag antenna impedance and resonant frequency are adjusted.The fabricated metal crack sensor tag has a simulated resonance frequency of 914.7 MHz in a metal environment,and an echo loss of-33.94 d Bi at the resonance frequency.It has good metal resistance and sensing performance.(2)According to the characteristics of the correlation between the phase of the crack sensor tag and its position,a metal crack detection method based on the dual RFID tag phase is proposed,and a data acquisition scheme is designed to dewrap and denoise the original phase stream.Through the crack width identification scheme based on the interval and the crack width identification scheme based on the KNN classification algorithm,the detection accuracy of the method is verified.After verification,under the two crack width identification schemes,the detection accuracy of this method can reach 88.5% and 98.25% respectively.(3)In order to simplify the steps of detecting cracks in metal structures based on radio frequency identification technology,an RFID reader control software was developed based on the B/S structure design.The software can set the working parameters of the Mercury6 reader and control the Mercury6 reader to collect tag data through fixed frequency reading,scanning frequency reading or single reading,and store the data in the database in real time.