Research On Wireless Passive Temperature And Strain Dual-parameter Sensor For Rotating Environment Testing

There is an increasing demand for monitoring temperature,pressure,strain,and other parameters in high-speed rotating environments.Rolling bearings are exten-sively used in various mechanical devices and precision instruments.During high-speed rotation of the bearing,the temperature of the bearing can increase abruptly due to friction,affecting the normal operation of the device.In addition,the structure of the bearing will be gradually deformed and damaged depending on the action of cyclic loading,leading to bearing failure or even fracture in severe cases.Therefore,it is of great significance to develop sensors for temperature and strain measurements of bearings to determine the safety and stability of engineering components.This study designs a new multiresonance,multiplexing,wireless,passive inductance capacitance(LC)temperature and strain sensor.The sensor has two capacitors connected at different locations(turns)on the same inductor to achieve simultaneous temperature and strain measurements.The plate capacitor is connected to the inner part of the inductor to test the temperature and the other interdigital capacitor is connected to the outer part of the inductor to test the strain,thus forming two LC loops.Temperature and strain changes are monitored according to the resonant frequency changes.In this thesis,a series of highperformance sensor researches are carried out in response to the problems of testing various parameters in a rotating environment,including the design of temperature-strain integrated multi-parameter sensors,sensitive mechanism analysis,preparation,and application of sensors in actual environments the study.The main research content includes the following aspects:1.The equivalent circuit model of LC wireless passive sensor is built,and the basic principle of LC wireless passive resonant sensor and the influence of each sensitive parameter unit on the resonant frequency of the sensor are analyzed.The classification of LC wireless passive sensor is studied,including capacitance type and resistance type,and the measuring method is also studied.2.The LC temperature-strain integrated sensor is designed and studied.The structure of the sensor is optimized through High Frequency Structure Simulator(HFSS)simulations to realize frequency separation of the two parameters and avoid mutual interference between the two signals.The distribution of electric field is also analyzed.3.The selection of several flexible substrates and different methods of fabricating the sensor are discussed.Finally,the sensor is fabricated on the polyimide(PI)film by electroplating technology.4.A strain cantilever beam test device was set up to test the temperature and strain of the new multi-resonant multiplexed sensor.The experimental results show that the temperature-strain sensor can operate stably from 25 ? to 85 ? with an average sensitivity of 27.3 k Hz/? within this temperature range.The sensor can detect strains in the range of 1000–5000 ?? with a strain sensitivity of 100 Hz/?? at 25 ?.