NFC Passive Wireless Measurement System And Its Application

In recent years,the coverage of wireless sensor networks has become more and more extensive.Passive,integrated,low power consumption and measurement flexibility have become new requirements for sensing nodes.Near Field Communication（NFC）technology,as an emerging passive wireless technology,has many advantages such as low environmental impact,short settling time,stable communication and high reliability.The use of NFC technology to design NFC passive wireless measurement systems can make the measurement system to realize miniaturization and low power consumption,is suitable for the complex and diverse environment.In this thesis,the NFC passive wireless measurement system is applied to actual engineering measurements through specific experimental measurements with the help of simulation tools and real measurement instruments,and the NFC passive wireless measurement system for torque and resistance reduction rate measurement of resistance reduction materials is designed.The following three aspects of work were accomplished.（1）Through the design of NFC passive wireless dynamic temperature measurement system,and through experiments,the maximum recognition distance is 10.5cm,the maximum stable communication distance is 9.5cm,and the measurement data error is 0.7℃.The stability,reliability and accuracy of the NFC passive wireless measurement system were initially verified by the experimental results.（2）An NFC passive wireless torque measurement system was designed for torque,an important kinetic parameter.Through static calibration experiments of the system,and transformation,processing and analysis of the resulting data,the linearity of the system was obtained as 0.729%,the hysteresis as 0.918%,the repeatability as 0.829%.The system is compact and does not require the installation of a battery,avoiding the limitations of traditional torque measurement methods.（3）In view of the important parameter of drag reduction rate of drag reduction materials in the rotating state,an NFC passive wireless rotary drag reduction measurement system is designed.The antenna was specially designed to meet the special measurement environment of the rotating state.The impedance of the antenna was 50.40 Ω,the return loss（S（1,1））was-41.85 d B and the voltage standing wave ratio（VSWR）was 1.03 at operating frequency as measured by a vector network analyser.In the control group,the thickness of the drag reduction coating is almost independent of the drag reduction rate under the condition of constant rotation speed.Under the condition of constant drag reduction coating thickness,the speed and drag reduction rate are approximately positively correlated.The passive wireless torque and drag reduction rate measurement system designed based on NFC technology provides a reference for NFC passive wireless measurement technology in practical engineering measurement applications.