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

(a) Schematic of two ultrasound intensity distributions; (b) Ultrasound intensity distributions were measured by the receiver according to its lateral displacement.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-17000-f006: (a) Schematic of two ultrasound intensity distributions; (b) Ultrasound intensity distributions were measured by the receiver according to its lateral displacement.

Mentions: Figure 6a shows the schematic of two ultrasound intensity distributions obtained by carrying out the experiment shown in Figure 3. When the receiver is displaced laterally in front of the transmitters, the data plots from two transmitters are represented through the utilization of the above mentioned Gaussian approximation as follows:(2)I1=12πσ02exp[−(x0−μ1)22σ02](3)I2=12πσ02exp[−(x0−μ2)22σ02](4)μ1+μ2=dwhere I1 and I2 show the ultrasound intensity transmitted by transmitters 1 and 2, respectively, x0 is the relative lateral displacement of the receiver from the origin, σ0 is the standard deviation of the ultrasound intensity distribution which is common to both transmitters, μ1 and μ2 are the original positions of the transmitters in x direction, and d is the interval between transmitters 1 and 2. Note that in the experiment detailed in this paper, the ultrasound transducers are alternately turned on and off, so each ultrasound beam is generated as an independent event. From Equations (2–4), the relative lateral displacement x0 is derived:(5)x0=Aln(I1I2)+B(6)A=−σ02d(7)B=d2


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

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

(a) Schematic of two ultrasound intensity distributions; (b) Ultrasound intensity distributions were measured by the receiver according to its lateral displacement.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-17000-f006: (a) Schematic of two ultrasound intensity distributions; (b) Ultrasound intensity distributions were measured by the receiver according to its lateral displacement.
Mentions: Figure 6a shows the schematic of two ultrasound intensity distributions obtained by carrying out the experiment shown in Figure 3. When the receiver is displaced laterally in front of the transmitters, the data plots from two transmitters are represented through the utilization of the above mentioned Gaussian approximation as follows:(2)I1=12πσ02exp[−(x0−μ1)22σ02](3)I2=12πσ02exp[−(x0−μ2)22σ02](4)μ1+μ2=dwhere I1 and I2 show the ultrasound intensity transmitted by transmitters 1 and 2, respectively, x0 is the relative lateral displacement of the receiver from the origin, σ0 is the standard deviation of the ultrasound intensity distribution which is common to both transmitters, μ1 and μ2 are the original positions of the transmitters in x direction, and d is the interval between transmitters 1 and 2. Note that in the experiment detailed in this paper, the ultrasound transducers are alternately turned on and off, so each ultrasound beam is generated as an independent event. From Equations (2–4), the relative lateral displacement x0 is derived:(5)x0=Aln(I1I2)+B(6)A=−σ02d(7)B=d2

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