Limits...
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

Normally distributed ultrasound intensity of the air-coupled ultrasound transducer.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4541918&req=5

sensors-15-17000-f005: Normally distributed ultrasound intensity of the air-coupled ultrasound transducer.

Mentions: Figure 5 shows the ultrasound intensity distribution of the air-coupled ultrasound transducer by conducting the experiment shown in Figure 2. In Figure 5, open circles show the ultrasound intensity as measured by the receiver in each position. The solid line shows the fitted Gaussian curve. It is clear that these plots can be approximated by the Gaussian curve fairly well. The fitted curve is expressed using the following normal distribution function:(1)f(x)=12πσ2exp[−(x−μ)22σ2]where x is the relative lateral displacement of the receiver from its origin, f(x) represents the standardized ultrasound intensity of the received ultrasound, σ is the standard deviation of the data plots, and μ is the position of the transmitter. In the following section, we will describe the measurement method for lateral displacement utilizing the characteristics of the air-coupled ultrasound transducer.


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

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

Normally distributed ultrasound intensity of the air-coupled ultrasound transducer.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-17000-f005: Normally distributed ultrasound intensity of the air-coupled ultrasound transducer.
Mentions: Figure 5 shows the ultrasound intensity distribution of the air-coupled ultrasound transducer by conducting the experiment shown in Figure 2. In Figure 5, open circles show the ultrasound intensity as measured by the receiver in each position. The solid line shows the fitted Gaussian curve. It is clear that these plots can be approximated by the Gaussian curve fairly well. The fitted curve is expressed using the following normal distribution function:(1)f(x)=12πσ2exp[−(x−μ)22σ2]where x is the relative lateral displacement of the receiver from its origin, f(x) represents the standardized ultrasound intensity of the received ultrasound, σ is the standard deviation of the data plots, and μ is the position of the transmitter. In the following section, we will describe the measurement method for lateral displacement utilizing the characteristics of the air-coupled ultrasound transducer.

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