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Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings.

Matsuya I, Matsumoto F, Ihara I - Sensors (Basel) (2015)

Bottom Line: The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side.In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced.When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Niigata, Japan. matsuya@mech.nagaokaut.ac.jp.

ABSTRACT
An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring.

No MeSH data available.


Related in: MedlinePlus

Experimental setup for measuring relative lateral displacement sensing using two transmitters.
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sensors-15-17000-f003: Experimental setup for measuring relative lateral displacement sensing using two transmitters.

Mentions: Figure 3 shows the experimental setup used for relative lateral displacement sensing. The measurement system is composed of two air-coupled ultrasound transducers as transmitters and the same transducer also used as a receiver. Two transmitters are immobilized at a fixed point side by side with a distance of 30 mm, whereas a receiver is separately arranged on the opposite side. The distance between the transmitters and the receiver is set at 60 mm. The origin is set to be the center of the transmitter 2. When the receiver is displaced parallel to the x direction from the origin, two ultrasound intensity distributions are measured by the receiver according to the x position of the receiver. As a static displacement test, the receiver on the X-stage is displaced ±15 mm and the measurement accuracy is evaluated. The required specification for the fluctuation value depends on the percentage of the length of each measurement range. For the health monitoring of a seismically isolated building, it is thought that if the fluctuation rate is less than 1% in each measurement range, a high-precision measurement will be successfully carried out. Next, a dynamic response experiment is conducted to verify the accuracy and capability to follow the dynamic movement in real-time. The receiver is moved ±15 mm with around 0.6 Hz in the dynamic response experiment. This movement of the stage simulates the relative movement of the superstructure in the seismically isolated building.


Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings.

Matsuya I, Matsumoto F, Ihara I - Sensors (Basel) (2015)

Experimental setup for measuring relative lateral displacement sensing using two transmitters.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541918&req=5

sensors-15-17000-f003: Experimental setup for measuring relative lateral displacement sensing using two transmitters.
Mentions: Figure 3 shows the experimental setup used for relative lateral displacement sensing. The measurement system is composed of two air-coupled ultrasound transducers as transmitters and the same transducer also used as a receiver. Two transmitters are immobilized at a fixed point side by side with a distance of 30 mm, whereas a receiver is separately arranged on the opposite side. The distance between the transmitters and the receiver is set at 60 mm. The origin is set to be the center of the transmitter 2. When the receiver is displaced parallel to the x direction from the origin, two ultrasound intensity distributions are measured by the receiver according to the x position of the receiver. As a static displacement test, the receiver on the X-stage is displaced ±15 mm and the measurement accuracy is evaluated. The required specification for the fluctuation value depends on the percentage of the length of each measurement range. For the health monitoring of a seismically isolated building, it is thought that if the fluctuation rate is less than 1% in each measurement range, a high-precision measurement will be successfully carried out. Next, a dynamic response experiment is conducted to verify the accuracy and capability to follow the dynamic movement in real-time. The receiver is moved ±15 mm with around 0.6 Hz in the dynamic response experiment. This movement of the stage simulates the relative movement of the superstructure in the seismically isolated building.

Bottom Line: The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side.In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced.When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Niigata, Japan. matsuya@mech.nagaokaut.ac.jp.

ABSTRACT
An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring.

No MeSH data available.


Related in: MedlinePlus