An active temperature compensated fiber Bragg grating(FBG)vibration sensor with a constant section cantilever beam is proposed for the simultaneous measurement of temperature and vibration,and the sensor is verified b...An active temperature compensated fiber Bragg grating(FBG)vibration sensor with a constant section cantilever beam is proposed for the simultaneous measurement of temperature and vibration,and the sensor is verified by a temperature compensation feedback system.The high-temperature vibration sensor is composed of a quartz cantilever beam and a femtosecond Bragg grating.The feedback control demodulation system of active temperature compensation can adjust the laser wavelength to stabilize the grating offset point and realize simultaneous measurement of temperature and vibration.On this basis,the performance of the sensor is tested and analyzed within the range of 20-400℃by setting up a high-temperature vibration test system.The experimental results show that the sensitivity of the sensor is about 132.33 mV/g,and the nonlinearity is about 3.33%.The sensitivity between the laser wavelength and temperature is about 0.01307 nm/℃.In addition,the active temperature compensated fiber Bragg grating vibration sensor has the advantages of a simple structure,stable performance,easy demodulation and high sensitivity.Moreover,the sensor can achieve high temperature vibration signal monitoring and has good practical application value.展开更多
A new nonlinear integral resonant controller（NIRC） is introduced in this paper to suppress vibration in nonlinear oscillatory smart structures. The NIRC consists of a first-order resonant integrator that provides ad...A new nonlinear integral resonant controller（NIRC） is introduced in this paper to suppress vibration in nonlinear oscillatory smart structures. The NIRC consists of a first-order resonant integrator that provides additional damping in a closed-loop system response to reduce highamplitude nonlinear vibration around the fundamental resonance frequency. The method of multiple scales is used to obtain an approximate solution for the closed-loop system.Then closed-loop system stability is investigated using the resulting modulation equation. Finally, the effects of different control system parameters are illustrated and an approximate solution response is verified via numerical simulation results.The advantages and disadvantages of the proposed controller are presented and extensively discussed in the results. The controlled system via the NIRC shows no high-amplitude peaks in the neighboring frequencies of the resonant mode,unlike conventional second-order compensation methods.This makes the NIRC controlled system robust to excitation frequency variations.展开更多
基金National Natural Science Foundation of China(No.51935011)Natural Science Foundation of Shanxi Province of China(No.201901D111160)Innovative Research Group Project of National Science Foundation of China(No.51821003)。
文摘An active temperature compensated fiber Bragg grating(FBG)vibration sensor with a constant section cantilever beam is proposed for the simultaneous measurement of temperature and vibration,and the sensor is verified by a temperature compensation feedback system.The high-temperature vibration sensor is composed of a quartz cantilever beam and a femtosecond Bragg grating.The feedback control demodulation system of active temperature compensation can adjust the laser wavelength to stabilize the grating offset point and realize simultaneous measurement of temperature and vibration.On this basis,the performance of the sensor is tested and analyzed within the range of 20-400℃by setting up a high-temperature vibration test system.The experimental results show that the sensitivity of the sensor is about 132.33 mV/g,and the nonlinearity is about 3.33%.The sensitivity between the laser wavelength and temperature is about 0.01307 nm/℃.In addition,the active temperature compensated fiber Bragg grating vibration sensor has the advantages of a simple structure,stable performance,easy demodulation and high sensitivity.Moreover,the sensor can achieve high temperature vibration signal monitoring and has good practical application value.
文摘A new nonlinear integral resonant controller（NIRC） is introduced in this paper to suppress vibration in nonlinear oscillatory smart structures. The NIRC consists of a first-order resonant integrator that provides additional damping in a closed-loop system response to reduce highamplitude nonlinear vibration around the fundamental resonance frequency. The method of multiple scales is used to obtain an approximate solution for the closed-loop system.Then closed-loop system stability is investigated using the resulting modulation equation. Finally, the effects of different control system parameters are illustrated and an approximate solution response is verified via numerical simulation results.The advantages and disadvantages of the proposed controller are presented and extensively discussed in the results. The controlled system via the NIRC shows no high-amplitude peaks in the neighboring frequencies of the resonant mode,unlike conventional second-order compensation methods.This makes the NIRC controlled system robust to excitation frequency variations.
