scholarly journals Sensorless Self-Excited Vibrational Viscometer with Two Hopf Bifurcations Based on a Piezoelectric Device

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1127
Author(s):  
Shinpachiro Urasaki ◽  
Hiroshi Yabuno ◽  
Yasuyuki Yamamoto ◽  
Sohei Matsumoto

In this study, we propose a high-sensitivity sensorless viscometer based on a piezoelectric device. Viscosity is an essential parameter frequently used in many fields. The vibration type viscometer based on self-excited oscillation generally requires displacement sensor although they can measure high viscosity without deterioration of sensitivity. The proposed viscometer utilizes the sensorless self-excited oscillation without any detection of the displacement of the cantilever, which uses the interaction between the mechanical dynamics of the cantilever and the electrical dynamics of the piezoelectric device attached to the cantilever. Since the proposed viscometer has fourth-order dynamics and two coupled oscillator systems, the systems can produce different self-excited oscillations through different Hopf bifurcations. We theoretically showed that the response frequency jumps at the two Hopf bifurcation points and this distance between them depends on the viscosity. Using this distance makes measurement highly sensitive and easier because the jump in the response frequency can be easily detected. We experimentally demonstrate the efficiency of the proposed sensorless viscometer by a macro-scale measurement system. The results show the sensitivity of the proposed method is higher than that of the previous method based on self-excited oscillation with a displacement sensor.

Author(s):  
Eisuke Higuchi ◽  
Hiroshi Yabuno ◽  
Yasuyuki Yamamoto ◽  
Sohei Matsumoto

Abstract In recent years, measurement methods that use resonators as microcantilevers have attracted attention because of their high sensitivity, high accuracy, and rapid response time. They have been widely utilized in mass sensing, stiffness sensing, and atomic force microscopy (AFM), among other applications. In all these methods, it is essential to accurately detect shifts in the natural frequency of the resonator caused by an external force from a measured object or sample. Experimental approaches based on self-excited oscillation enable the detection of these shifts even when the resonator is immersed in a high-viscosity environment. In the present study, we experimentally and theoretically investigate the nonlinear characteristics of a microcantilever resonator and their control by nonlinear feedback. We show that the steady-state response amplitude and the corresponding response frequency can be controlled by cubic nonlinear velocity feedback and cubic nonlinear displacement feedback, respectively. Furthermore, the amplitude and frequency of the steady-state self-excited oscillation can be controlled separately. These results will expand application of measurement methods that use self-excited resonators.


Author(s):  
Abbas Amini ◽  
Hamid Mehdigholi ◽  
Mohammad Elahinia

The shape memory alloys (SMAs) and smart composites have a large use in high and low level industry, while a lot of research is being done in this field. The existence of smart composite structures is because of the advance mechanical benefits of the above materials. This work refers to dynamic and quasi static nonlinear explanation of these materials. After mathematical model consideration on the rate of strain, a model which is about martensite ratio of NiTi has been presented. This work has been done because of the high sensitivity of these materials to strain rate and use of visual and measurable engineering criteria to access other variables. As the martensite ratio is not engineering measurable amount, it needs to have macro scale property to measure this important nano scale criteria. Relative experiments are done to show the rate dependency of NiTi.


Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1184 ◽  
Author(s):  
Mohammad Abdolrazzaghi ◽  
Mojgan Daneshmand

This paper presents a novel planar multifunctional sensor that is used to monitor physical variations in the environment regarding distance, angle, and stretch. A double split-ring resonator is designed at 5.2 GHz as the core operating sensor. Another identical resonator is placed on top of the first one. The stacked configuration is theoretically analyzed using an electric circuit model with a detailed parameter extraction discussion. This design is first employed as a displacement sensor, and a compelling high sensitivity of 500 MHz/mm is observed for a wide dynamic range of 0-5 mm. Then, in another configuration, the stacked design is used as a rotation sensor that results in a high sensitivity of 4.5 MHz/ ° for the full range of 0-180 ° . In addition, the stacked resonator is utilized as a strain detector, and a 0–30% stretch is emulated with a linear sensitivity of 12 MHz/%. Measurements are well in congruence with simulated results, which proves the accurate functionality of the sensor in tracking mechanical deformations, all in a single compact contraption.


2014 ◽  
Vol 4 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Saeed Olyaee ◽  
Morteza Azizi

2017 ◽  
Vol 19 (11) ◽  
pp. 115804 ◽  
Author(s):  
Lanting Ji ◽  
Guobing He ◽  
Yang Gao ◽  
Yan Xu ◽  
Honglei Liang ◽  
...  

Author(s):  
Akira Maekawa ◽  
Takashi Tsuji ◽  
Tsuneo Takahashi

Abstract The present paper proposes an improved contactless measurement method for vibration stress of piping systems, by which the measurement time is shorter and the measuring works are more simple. The proposed method includes two processes, in which the bending mode shape of piping vibration is identified by a transmission-type light emitting diode (LED) displacement sensor and the vibration stress is calculated based on beam theory using the approximated curve of the bending mode shape. The proposed method uses one advanced LED displacement sensor to measure the vibration stress though multiple conventional LED sensors must be used in the previous method developed by the authors. Therefore, the measuring system could be reduced in size and a light-weight and portable measurement instrument was developed. The measurement accuracy and reliability of the new method were validated by the vibration experiment using a mock-up piping system.


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