KR102579391B1 - System for measuring displacement of structure by rotational angle detection and signal processing, and method for the same - Google Patents

Abstract

In order to measure the displacement only with an inclinometer, the displacement is calculated by integrating the rotation angle measured by the inclinometer once, thereby eliminating the phenomenon of pushing, and thus the displacement of the structure can be measured with almost no error from the actual value. , the number of measurement sensors can be significantly reduced by installing only one type of inclinometer to measure the displacement at an arbitrary location of the structure. Additionally, the displacement error can be reduced by calculating the displacement by integrating the rotation angle data measured by the inclinometer installed in the structure. is small, and can be used for impact coefficient selection and load testing by measuring both static and dynamic displacement. In addition, the rotation angle is measured using a high-resolution inclinometer with a large sampling frequency, and static and dynamic deflection are simultaneously extracted through signal processing. A system and method for measuring structural displacement through rotation angle measurement and signal processing that can measure static and dynamic deflection by numerical integration of rotation angle data measured for all types of bridges, including suspension bridges. This is provided.

Description

Structure displacement measurement system and method through rotation angle measurement and signal processing {SYSTEM FOR MEASURING DISPLACEMENT OF STRUCTURE BY ROTATIONAL ANGLE DETECTION AND SIGNAL PROCESSING, AND METHOD FOR THE SAME}

The present invention relates to a structure displacement measurement system. More specifically, to measure the displacement caused by external forces of SOC (Social Overhead Capital) structures such as bridges and wind towers, an inclinometer is attached and installed on the structure to measure the rotation angle and signal processing. It relates to a structural displacement measurement system and method that measures static and dynamic displacement through.

In general, for the safe use of a structure, it is essential to accurately measure the behavior of the structure due to various external forces. In particular, the displacement of the structure is most important for intuitively analyzing whether the structure is operating normally.

However, although the displacement of small-scale members can be easily measured indoors, most SOC structures are large in scale, so it is not simple to measure the displacement due to external forces.

In particular, in the case of bridges, which are important SOC facilities, load-bearing capacity evaluations are performed to determine safety at a specific point in time.

At this time, deflection, which is the vertical displacement caused by vehicles traveling on the bridge, is divided into static deflection and dynamic deflection to obtain the impact factor, which is used to evaluate load carrying capacity. I am using it.

As a method of measuring the vertical displacement of such structures,

For example, a method of directly measuring displacement using a Linear Variable Differential Transducer (LVDT), Global Navigation Satellite System (GNSS), Laser Doppler Vibrometer (LVD), etc. There is also a method of indirectly estimating the displacement through data processing after measuring acceleration, strain, and image information.

Specifically, the linear variable displacement transducer (LVDT), a device that directly measures the displacement of a structure, is a contact sensor and requires support facilities for sensor installation.

Because of this, there is a limitation in that displacement measurement is not possible in cases where it is difficult to install support facilities such as rivers, seas, roads, and valleys.

Navigation satellite systems (GNSS) have low measurement precision and difficulty in measuring dynamic deflection. In particular, there is a limitation in that measurement is only possible in places where satellite signals can be received.

The laser Doppler vibrometer (LVD) is a non-contact sensor and has few restrictions on the installation point, but it must be installed at a point where the displacement of the structure is collimated and has the limitation of being quite expensive.

Meanwhile, in the case of an indirect estimation method of structural displacement using acceleration data, dynamic displacement can be estimated through double integration of acceleration over time.

At this time, due to the accumulation of errors in measurement noise during double integration, a large drift phenomenon occurs in the low-frequency region related to static displacement, which limits the possibility of accurate displacement measurement.

Additionally, in the case of an indirect estimation method of structural displacement using strain data,

It is a method of indirectly estimating displacement by integrating multi-point strain data over space, but the values such as bending stiffness and neutral axis of the bridge required for data conversion are different from the values calculated based on design books and the actual bridge values. Because they are different from each other, there is a limitation that they must be calibrated by installing a separate displacement sensor directly in the field.

In addition, in the case of an indirect estimation method of structural displacement using acceleration and strain data, the neutral axis is estimated based on the acceleration measured through an acceleration sensor after going through the process of converting the strain into displacement, and the displacement is then calibrated to an accurate scale. take the method

However, the method of indirectly estimating the displacement at a specific point by simultaneously utilizing acceleration measurements and structure strain information has a limitation in that it requires all structural information of the structure to estimate the neutral axis of the structural cross section.

Meanwhile, as prior art related to the inclination sensor, Japanese Patent Publication No. 1995-146141 discloses an invention titled “vertical reference device.”

An angle inclination sensor is attached from the reference axis of the structure to detect the angular inclination, and provides a dynamic inclination signal by integrating the detected angular rate signal.

In addition, by providing a signal representing the angular displacement with respect to the reference axis,

The dynamic tilt signal and the angular displacement signal are filtered from a high-frequency/low-frequency filter and amplified through the first and second amplifiers to generate an amplified signal,

Controlling the vertical reference of a structure with respect to a reference axis is disclosed by combining the first and second amplified signals.

However, in the case of a vertical reference device according to the prior art, the angle, not the displacement of the structure, is measured to control the verticality standard, and in this case, integration is a signal processing process performed to convert the measured angular rate signal into an angle. corresponds to

Accordingly, the vertical reference device according to the prior art can be applied to an attitude control system through electrical and electronic processing used in tilt decoupling technology of ships, such as ship platforms and ship helipads.

Meanwhile, as a prior art using an acceleration sensor and an inclination sensor, Republic of Korea Patent No. 10-1754488 discloses an invention titled “Method for measuring structural displacement history using acceleration information and rotation information,” which is shown in FIGS. 1A to 1 This is explained with reference to 1c.

Figure 1a is a conceptual diagram showing a structure displacement history measuring device according to the prior art, Figure 1b is an operation flow chart showing a structure displacement history measuring method according to the prior art, and Figure 1c is a structure displacement history measuring device shown in Figure 1a. This is a drawing showing an example of application.

As shown in Figure 1a, the displacement history measuring device 10 of a structure according to the prior art is configured to include a pair of acceleration sensors 12a and 12b and an inclination sensor 13.

At this time, a pair of acceleration sensors 12a and 12b and an inclination sensor 13 are accommodated and installed in the case 11, and the case 11 can be installed at a location to be measured on the structure to be measured.

The tilt sensor 13 is installed vertically on the surface 20 of the structure at the position of measuring the displacement of the structure.

A pair of acceleration sensors 12a and 12b are connected to the inclination sensor 13 through a connection member 14 such as a frame or bracket and are configured to operate integrally with the inclination sensor 13.

Accordingly, the displacement history measuring device of a structure according to the prior art calculates and processes the displacement of the structure using the rotation angle data measured by the inclination sensor 13 and the acceleration data measured by the pair of acceleration sensors 12a and 12b. do.

In addition, referring to FIGS. 1A and 1B, the method of measuring the displacement history of a structure according to the prior art is,

First, the rotation angle data is measured by the inclination sensor 13 installed in the vertical direction at the displacement measurement position of the structure, and a pair of acceleration sensors are connected to the inclination sensor 13 and operate integrally with the inclination sensor 13. Acceleration data is measured by (12a, 12b) (S10).

Next, only the acceleration value in the vertical direction is calculated by correcting the gravitational influence caused by the rotation of the acceleration sensors 12a and 12b in the acceleration data of the acceleration sensors 12a and 12b using the rotation angle data of the inclination sensor 13. Perform acceleration compensation (S20).

Next, the measurement noise of the acceleration sensors 12a and 12b and the tilt sensor 13 is removed by frequency band filtering (S30).

Next, the displacement of the structure is calculated by double integrating the acceleration value that has undergone acceleration correction and noise removal (S40).

Next, the total of the errors due to the measurement errors of the acceleration sensors 12a and 12b and the inclination sensor 13 is calculated, and the total of the errors is calculated as the slope over time and then corrected (S50).

Next, the final displacement of the structure is calculated using the displacement values of the pair of tilt sensors (12a, 12b) corrected by error correction (S60).

In other words, by using the inclination sensor 13 simultaneously with the acceleration sensors 12a and 12b, the inclination sensor 13 can be used like the acceleration sensors 12a and 12b even though a large error at the moment of measurement occurs depending on the type of sensor. Since errors do not accumulate because an integration process is not performed, the error accumulation tendency of acceleration data can be corrected with data from the inclination sensor 13.

Accordingly, the method of measuring the displacement history of a structure according to the prior art is a method of calculating the vertical displacement history of the sensor attachment point in the structure or member, and measures the displacement history in three axes according to the sensor installation direction and the sensor measurement direction. It can be calculated.

At this time, the structure's displacement history measuring device 10 according to the prior art, as shown in Figure 1c, can not only be used to measure the displacement of the cable, but also can be used to measure the displacement of the structure, especially the displacement of the underwater structure. It can be.

In the case of a device for measuring the displacement history of a structure according to conventional technology, it is very simple to install and uses acceleration and rotation angle information that anyone can easily measure, preventing the calculated displacement from diverging due to the accumulation of errors.

It is possible to simply measure the displacement of a structure by replacing existing complex methods without being affected by the uncertainty of initial conditions.

In addition, because it uses the acceleration and rotation angle of the structure, it can be applied to various structures without restrictions on the type of structure. In particular, it can be applied to cases where measurement is almost impossible, such as underwater structures.

However, in the case of a device for measuring the displacement history of a structure according to the conventional technology, both types of inclination sensors and acceleration sensors are used simultaneously. At this time, the acceleration measured by the acceleration sensor is integrated twice to calculate the displacement, but the displacement measured by the inclination sensor is calculated. Acceleration data must be corrected with slope data.

Here, the inclination sensor is a means of correcting the error in the displacement obtained by the acceleration sensor, and basically, the deflection converted to acceleration data has an error inherent in it. In this case, as the number of integration orders increases, the drift of the physical quantity occurs and the actual value There is a problem in that errors become larger.

In addition, in the case of a device for measuring the displacement history of a structure according to the prior art, the disadvantage of error accumulation due to the secondary integration of acceleration data is solved by using an inclinometer, and two types of accelerometer and inclinometer are used at the location where the displacement is to be measured. Since displacement is calculated by installing at the same time, the number of sensors installed increases as much as the location where the displacement is to be measured. If displacement is needed at 3 positions, a total of 9 sensors are needed, which poses a problem in that the number of measurement sensors increases.

Meanwhile, as prior art related to dynamic displacement calculation, Republic of Korea Patent Publication No. 20178410 discloses an invention titled “Dynamic displacement calculation device and dynamic displacement calculation method,” which will be described with reference to FIGS. 2A and 2B.

FIG. 2A is a configuration diagram showing a dynamic displacement calculation device according to the prior art, and FIG. 2B is a diagram illustrating the dynamic displacement measured by a displacement measuring device included in the dynamic displacement calculation device shown in FIG. 2A.

2A and 2B, the dynamic displacement calculation device 30 according to the prior art includes an acceleration sensor 31, a displacement sensor 32, a Kalman filter unit 33, and a calculation unit 34. .

The acceleration sensor 31 measures acceleration (ACC) and angular displacement (ROT) of the target object 35.

The displacement sensor 32 measures the dynamic displacement (DISP) of the target object 35.

The Kalman filter unit 33 calculates the velocity (VEL) and corrected dynamic displacement (CDISP) of the target object 35 based on acceleration (ACC), angular displacement (ROT), and dynamic displacement (DISP), and calculates velocity (VEL). ) and the bias value (BIAS) included in the acceleration (ACC) is calculated based on the corrected dynamic displacement (CDISP).

Computation unit 34 provides a final dynamic displacement (FDISP) based on the corrected dynamic displacement (CDISP) and the bias value (BIAS).

Specifically, the acceleration sensor 31 can measure the acceleration (ACC) of the target object 35, as shown in FIG. 2B.

For example, the position of the target object 35 at the first time may be the first position P1. The location of the target object 35 at a second time after the first time may be the second location P2.

While the target object 35 moves from the first position P1 to the second position P2, the acceleration sensor 31 may measure the acceleration (ACC) of the target object 15.

At this time, while the target object 35 moves from the first position P1 to the second position P2, the acceleration (ACC) of the target object 35 measured by the acceleration sensor 31 is the first acceleration (ACC1). ), the second acceleration (ACC2), and the third acceleration (ACC3).

Additionally, referring to FIG. 2B, the acceleration sensor 31 can measure the angular displacement (ROT) of the target object 35.

For example, the position of the target object 35 at the first time may be the first position P1. The location of the target object 35 at a second time after the first time may be the second location P2.

At this time, while the target object 35 moves from the first position P1 to the second position P2, the acceleration sensor 31 may measure the angular displacement (ROT) of the target object 35.

In addition, while the target object 35 moves from the first position P1 to the second position P2, the angular displacement (ROT) of the target object 35 measured by the acceleration sensor 31 is the first angular displacement. (ROT1), a second angular displacement (ROT2), and a third angular displacement (ROT3).

For example, the first angular displacement ROT1 may be a change in angle along the XY plane centered on the first position P1 among the angular displacements ROT of the target object 35 .

The second angular displacement ROT2 may be a change in angle along the YZ plane centered on the first position P1 among the angular displacements ROT of the target object 35 .

The third angular displacement ROT3 may be a change in angle along the ZX plane centered on the first position P1 among the angular displacements ROT of the target object 35 .

In other words, in the case of a dynamic displacement calculation device according to the prior art,

An acceleration meter is provided to measure the acceleration and angular displacement of the target object, and a displacement meter is provided to measure dynamic displacement.

After calculating the speed and corrected dynamic displacement of the object based on acceleration/angle/dynamic displacement, the final dynamic displacement can be calculated through a Kalman filter unit to calculate the bias value included in the acceleration based on the speed and corrected displacement.

Accordingly, according to the dynamic displacement calculation device according to the prior art, the bias value included in the acceleration is calculated based on the speed and corrected dynamic displacement of the target object determined according to the acceleration, angular displacement, and dynamic displacement of the target object. It can provide the final dynamic displacement corresponding to the exact dynamic displacement.

However, in the case of the dynamic displacement calculation device according to the prior art, a displacement meter is installed to calculate only the dynamic displacement without regard to the static displacement. In addition, acceleration data must be integrated twice, so there is a problem in that the error in the calculated displacement increases.

Meanwhile, as a prior art related to a method of indirectly estimating displacement through data processing after measuring image information, an invention titled "Method for measuring displacement of a structure using image processing" is disclosed in Republic of Korea Patent No. 100458290. This is explained with reference to Figure 3.

Figure 3 is a perspective view schematically showing the process of measuring the displacement of a structure in a method of measuring the displacement of a structure using image processing according to the prior art.

The method of measuring the displacement of a structure using image processing according to the conventional technology first obtains image data by photographing the reference marks 52 and 52a within the mark 51 of the structure 50 using a camera 40.

For this purpose, as illustrated in FIG. 3, two reference marks 52 and 52a are displayed inside the mark 51 on the structure 50, and a camera 40 is positioned at a predetermined distance from the mark 51. ) is installed to capture images of changes in the reference marks 52 and 52a displayed within the mark 51 according to the movement of the structure 50.

Next, the image data obtained by the camera 50 is transmitted to the computer 60, and then the coordinates of the reference marks 52 and 52a are calculated from the transmitted image data using an image processing technique.

Next, using the coordinates of the reference marks (52, 52a), the interval between the reference marks (52, 52a) in the image processed image is calculated in basic image units, and the reference marks (52, 52, 52a) is measured, and the relationship between the actual distance to the image basic unit is calculated based on the ratio between the distance between the reference marks 52 and 52a obtained in the image basic unit and the actual measured physical interval. do.

Next, as the structure 50 vibrates, continuous images in which the reference marks (52, 52a) move are image processed, and the amount of displacement of the reference marks (52, 52a) in the image-processed image is calculated as the image base. Measured in units.

Next, the displacement amount measured in image basic units is calculated as the actual distance based on the relationship with the calculated actual distance per image basic unit, and then the actual moving distance of the calculated reference marks 52, 52a is calculated as the movement over time. It is displayed as a path and printed.

According to a method of measuring the displacement of a structure using image processing according to the prior art, the amount of vibration can be obtained by measuring the displacement of a large structure such as a bridge, building, or tower.

In addition, a method of relative comparison is used between the actual distance between reference marks in already known marks and the distance and moving distance between reference marks in the image obtained as a result of image processing of the captured video, even if the distance between the camera and the mark changes. It's okay.

However, in the case of the method of measuring the displacement of a structure using image processing according to the conventional technology, the method involves obtaining image data by photographing a reference mark within the structure's mark with a camera and then indirectly estimating the displacement through image processing. There are limitations in that it is difficult to measure displacement precisely and it is difficult to apply it easily.

Meanwhile, as prior art related to the laser Doppler vibrometer, Republic of Korea Patent No. 102258344 discloses an invention titled "Displacement measuring device for bridge load testing using a laser Doppler displacement measuring device and load test method using the same", Figure 4 It is explained with reference to .

Figure 4 is a configuration diagram showing a displacement measuring device for bridge load testing using a laser Doppler displacement measuring device according to the prior art.

Referring to FIG. 4, the displacement measuring device 70 for bridge load testing using a laser Doppler displacement measuring device according to the prior art,

A displacement measurement device for bridge load testing using a laser Doppler displacement meter (73) to measure the displacement of the bridge (81) from a distance,

It consists of a support member 71, a driving part 72, a laser Doppler displacement meter 73, an inclinometer 74, a driving part control part 75, and a control part 76, and also a zoom camera 77 and a cloud 78. It may further include a wireless transmitter 82 and a wireless receiver 83.

The drive unit 72 is formed on the support member 71 and consists of a transverse rotation part and a longitudinal rotation part. The transverse rotation part consists of a transverse rotation frame, a transverse drive motor, and a transverse encoder, and the longitudinal rotation part It consists of a longitudinal rotation frame, a longitudinal drive motor, and a longitudinal encoder.

The laser Doppler displacement measuring device 73 is placed at the top of the driving unit 72 and rotates up, down, left and right by the driving unit 72 and emits a laser beam to measure the amount of displacement of the bridge 81.

The inclinometer 74 is installed in the laser Doppler displacement measuring device 73 to measure the horizontal/vertical inclination of the laser Doppler displacement measuring device 73.

The driving unit control unit 75 controls the driving of the driving unit 72, and stores one or more coordinate data for one or more bridges 81 to be measured, and data on the inclination amount through the inclinometer 74 and laser Doppler The displacement value measured by the displacement measuring device 73 is calculated and stored.

The control unit 76 stores and monitors the data stored in the drive control unit 75 and simultaneously performs structural analysis.

In other words, using a laser Doppler displacement measuring device and an inclinometer installed at a distance, the horizontal/vertical tilt amount of the laser Doppler displacement measuring device is applied to calculate and store the displacement amount of the bridge through the driving unit control unit 75.

At this time, the laser Doppler displacement measuring device 73 is sequentially rotated to a plurality of coordinates using one or more coordinate data for one or more bridges to be measured stored in the driving unit control unit 75, and the displacement amount for the bridge at the plurality of coordinate points is automatically calculated. Measure and calculate.

Accordingly, in the case of a displacement measuring device for bridge loading testing using a laser Doppler displacement measuring device according to the conventional technology, a laser Doppler displacement measuring device and an inclinometer are used to measure bridges that are constructed in the sea, rivers, and mountainous terrain and for which loading testing is not possible at the lower part of the bridge. Load tests can be performed accurately.

In addition, according to the displacement measuring device for bridge load testing using a laser Doppler displacement measuring device according to the conventional technology, data for a plurality of coordinates is inputted in advance into the driving unit control unit, and then the laser Doppler displacement measuring device is rotated to each coordinate during the loading test of the bridge. By automatically performing load tests at multiple locations at once, operator convenience and workability can be improved.

However, in the case of a displacement measuring device for bridge load testing using a laser Doppler displacement measuring device according to conventional technology, there are few restrictions on the installation point, but there is a restriction that it must be installed at a point where the displacement of the structure is collimated, and it has the limitation of being quite expensive. there is.

Ultimately, in a situation where various technologies for measuring structural displacement, such as imaging, acceleration strain measurement, and laser measurement, are being actively developed recently, there is an urgent need to develop technology that can easily and precisely measure displacement in the simplest way.

Republic of Korea Patent No. 101754488 (registration date: June 29, 2017), title of invention: “Method of measuring structural displacement history using acceleration information and rotation information” Republic of Korea Patent Publication No. 20178410 (publication date: January 24, 2017), title of invention: “Dynamic displacement calculation device and dynamic displacement calculation method” Republic of Korea Patent No. 100458290 (registration date: November 12, 2004), title of invention: “Method of measuring displacement of a structure using image processing” Republic of Korea Patent No. 102258344 (registration date: May 25, 2021), title of invention: “Displacement measuring device for bridge load testing using a laser Doppler displacement measuring device and load test method using the same” Japanese Patent Publication No. 1995146141 (publication date: June 6, 1995), title of invention: “Vertical reference device” Republic of Korea Patent No. 101452171 (registration date: October 13, 2014), title of invention: “Method for estimating displacement of tower-type structures”

The technical problem to be achieved by the present invention to solve the above-mentioned problems is to calculate the displacement by integrating the rotation angle measured by the inclinometer once so that the displacement can be measured only with an inclinometer, so that there is no slipping phenomenon, and accordingly, the actual value The purpose is to provide a structure displacement measurement system and method through rotation angle measurement and signal processing that can measure the displacement of a structure with almost no error.

Another technical problem to be achieved by the present invention is to provide a structural displacement measurement system through rotation angle measurement and signal processing that can significantly reduce the number of measurement sensors by measuring displacement at all locations of the structure by installing only one type of inclinometer. and to provide a method thereof.

Another technical task to be achieved by the present invention is to calculate the displacement by integrating the rotation angle data measured by the inclinometer installed on the structure once, so that the displacement error is small, and by measuring both static and dynamic displacement, impact coefficient calculation and load testing. The purpose is to provide a system and method for measuring structural displacement through rotation angle measurement and signal processing that can be utilized in .

As a means of achieving the above-described technical problem, the structural displacement measurement system through rotation angle measurement and signal processing according to the present invention measures structural displacement through rotation angle measurement and signal processing to calculate the displacement for evaluating the load carrying capacity of the structure. In the system, the displacement calculated to evaluate the load carrying capacity of the structure is obtained by receiving a rotation angle signal collected according to external force from an inclinometer attached to the structure, and converting the received rotation angle signal into the rotation angle history of the inclinometer attachment point over time. It is expressed as a rotation angle curve for the inclinometer attachment section for each measurement time zone, and the rotation angle curve is represented as a displacement curve for the inclinometer attachment section for each measurement time zone, and the displacement history of an arbitrary point within the inclinometer attachment section for each measurement time zone is expressed as Convert it to be calculated,
A data logger is attached to the structure to enable rotation angle collection and collects rotation angle signals measured from each inclinometer that measures rotation angle signals according to external forces; And a manager terminal that receives the rotation angle signal wirelessly from a communication module that wirelessly transmits the rotation angle signal collected by the data logger and processes the signal to calculate the displacement for evaluating the load carrying capacity of the structure.
The manager terminal represents the received rotation angle signal as a rotation angle history of the inclinometer attachment point over time, represents it as a rotation angle curve for the inclinometer attachment section for each measurement time period, and represents the displacement for the inclinometer attachment point for each measurement time period. It is expressed as a curve, converted into the displacement history of the inclinometer attachment section for each measurement time period, and signal processed to calculate the displacement for evaluating the load carrying capacity of the structure,
The manager terminal includes a data collection unit that collects the rotation angle signal collected by the data logger via the communication module; a rotation angle curve selection unit that selects a rotation angle curve suitable for the characteristics of the structure according to the collected rotation angle signal; a displacement curve determination unit that determines a displacement curve of the structure due to an external force by integrating the selected rotation angle curve once; A signal processing unit that processes signals to filter displacement in a specific band; and a static and dynamic displacement determination unit that determines the static displacement and dynamic displacement of the entire structure, respectively.

As a means to achieve the above-described technical problem, the method of measuring structural displacement through rotation angle measurement and signal processing according to the present invention includes the steps of a) attaching and installing an inclinometer capable of collecting rotation angles on the structure; b) each of the inclinometers measuring a rotation angle signal according to an external force; c) a manager terminal collecting the rotation angle signal and selecting a rotation angle curve suitable for the characteristics of the structure; d) the manager terminal determining a displacement curve of the structure due to an external force by integrating the selected rotation angle curve once; e) the manager terminal processing a signal to filter displacement in a specific band; and f) determining, by the manager terminal, a static displacement and a dynamic displacement of an arbitrary part of the structure, respectively, wherein the manager terminal wirelessly receives a rotation angle signal and calculates a displacement for evaluating the load carrying capacity of the structure. The signal is processed to do so.

According to the present invention, there is no drift by calculating the displacement by integrating the rotation angle measured by the inclinometer once so that the displacement can be measured only with an inclinometer. Accordingly, the structure can be measured with almost no error from the actual value. Displacement can be measured.

According to the present invention, the number of measurement sensors can be significantly reduced by installing at least five inclinometers of only one type to measure displacement at arbitrary positions of the structure.

According to the present invention, the displacement is calculated by integrating the rotation angle data measured by the inclinometer installed on the structure once, so the displacement error is small, and both static and dynamic displacement can be measured, which can be used for impact coefficient selection and load testing.

According to the present invention, the rotation angle can be measured using a high-resolution inclinometer with a large sampling frequency, and the static and dynamic deflections can be simultaneously extracted through signal processing.

According to the present invention, static and dynamic deflections can be measured by numerical integration of rotation angle data measured for all types of bridges, including suspension bridges.

Figure 1a is a conceptual diagram showing a structure displacement history measuring device according to the prior art, Figure 1b is an operation flow chart showing a structure displacement history measuring method according to the prior art, and Figure 1c is a structure displacement history measuring device shown in Figure 1a. This is a drawing showing an example of application.
FIG. 2A is a configuration diagram showing a dynamic displacement calculation device according to the prior art, and FIG. 2B is a diagram illustrating the dynamic displacement measured by a displacement measuring device included in the dynamic displacement calculation device shown in FIG. 2A.
Figure 3 is a perspective view schematically showing the process of measuring the displacement of a structure in a method of measuring the displacement of a structure using image processing according to the prior art.
Figure 4 is a configuration diagram showing a displacement measuring device for bridge load testing using a laser Doppler displacement measuring device according to the prior art.
Figure 5 is a diagram for explaining the concept of a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.
Figure 6 is a configuration diagram of a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.
Figure 7 is a diagram showing selection of a rotation angle curve in a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.
Figure 8 is a diagram showing the determination of a displacement curve in a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.
Figure 9 is an operation flowchart showing a method of measuring structural displacement through rotation angle measurement and signal processing according to an embodiment of the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary. Additionally, terms such as “…unit” used in the specification refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

[Structure displacement measurement system (100) through rotation angle measurement and signal processing]

Figure 5 is a diagram for explaining the concept of a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.

As shown in Figure 5, the structural displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention includes an inclinometer (110a to 110n), a data logger (120), a communication module (130), and an administrator terminal. It is composed including (140).

The structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention is a structure within the inclinometer attachment section through the rotation angle signal measured at a specific part of the structure 200 using inclinometers 110a to 110n. (200) Measure the static and dynamic displacement of the entire area.

The displacement caused by external forces of the structure 200, for example, horizontal and vertical structures, such as vertical deflection caused by a bridge vehicle or horizontal displacement caused by wind of a wind tower, can be measured.

The structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention measures the rotation angle signal by attaching inclinometers (110a to 110n) capable of collecting precise rotation angles on a specific part of the structure 200. , select a rotation angle curve that suits the characteristics of the structure 200 and integrate the rotation angle curve once to find the displacement curve of the structure 200 due to external force.

Afterwards, the static displacement and dynamic displacement of any part of the structure 200 can be measured through a signal processing step that filters the displacement in a specific band.

In particular, when it is difficult to install the measuring instrument needed to measure displacement, when the measuring instrument itself is expensive and it is burdensome to install a displacement measuring instrument, or when the displacement that occurs in a small-scale bridge is so small that it is difficult to check the accurate history of the displacement. Therefore, the displacement of a structure can be measured precisely at low cost, regardless of surrounding conditions.

In the case of a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention, the rotation angle can be measured using a high-resolution inclinometer with a large sampling frequency, and static deflection and dynamic deflection can be simultaneously extracted through signal processing. In addition, static and dynamic deflection can be measured by numerical integration of the measured rotation angle data for all types of bridges, including suspension bridges.

For example, since a bridge can be measured by dividing it into static deflection and dynamic deflection by the vehicle 300, the impact coefficient can be obtained using this and can be used to evaluate load carrying capacity.

Meanwhile, Figure 6 is a configuration diagram of a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.

Figure 7 is a diagram showing selection of a rotation angle curve in a structural displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention;

Figure 8 is a diagram showing the determination of a displacement curve in a structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention.

Referring to FIG. 6, the structural displacement measurement system 100 through rotation angle measurement and signal processing according to an embodiment of the present invention includes inclinometers 110a to 110n, a data logger 120, a communication module 130, and a manager. Includes a terminal 140,

At this time, the manager terminal 140 includes a data collection unit 141, a rotation angle curve selection unit 142, a displacement curve determination unit 143, a signal processing unit 144, a static and dynamic displacement determination unit 145, It is composed of an impact coefficient calculation unit (146) and a management DB (147).

At least five inclinometers (110a to 110n) are attached and installed at a specific part of the structure 200 to enable precise rotation angle collection, and measure rotation angle signals according to external forces.

Here, the inclinometers (110a to 110n) measure the rotation angle signal at a sampling rate of 20 Hz or more, and the inclinometers (110a to 110n) are spaced at predetermined intervals in at least five specific parts of the structure 200. It can be attached.

Specifically, in the case of the structure displacement measurement system 100 through rotation angle measurement and signal processing according to an embodiment of the present invention, it is confirmed that the displacement of the structure 200 to be measured is accurate when installing the inclinometers 110a to 110n. In order to ensure that the signaled displacement diverges to an unrealistic value, the displacement due to the load is calculated at two points for the structure 200 supported at both ends and at one point for the structure supported at one end. Inclinometers (110a to 110n) are necessarily installed in the zero areas.

In addition, in the case of the structure displacement measurement system 100 through rotation angle measurement and signal processing according to an embodiment of the present invention, the rotation angle between two inclinometers or the rotation angle between all inclinometers attached to the structure 200 is various. It must be calculated using an interpolation formula. At this time, in order to minimize the increase in the error of the calculated rotation angle and ensure stability in the numerical integration process of converting it to displacement, the rotation angle between the two inclinometers is interpolated with a cubic spline curve, and through this, other than attaching the inclinometer is interpolated. Displacement can be measured accurately even at position.

In addition, while the existing technology is limited to the step of obtaining a static displacement curve of the structure by integrating the measured rotation angle curve once, the structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention In the case of (100), by finding out the history of displacement over time and measuring displacement that changes even at small time intervals, even dynamic displacement including impact effects due to vehicle movement can be obtained.

The data logger 120 collects and transmits the rotation angle signals measured from each of the at least five inclinometers 110a to 110n.

The communication module 130 wirelessly transmits the rotation angle signal collected by the data logger 120.

The manager terminal 140 wirelessly receives the rotation angle signal collected by the data logger 120 via the communication module 130, and determines the static displacement and dynamic displacement for evaluating the load carrying capacity of the structure 200. The signal is processed to calculate the displacement.

Here, as shown in FIG. 7, the manager terminal 140 represents the received rotation angle signal as a rotation angle history of the attachment point of the inclinometers 110a to 110n over time, and the inclinometer ( 110a~110n) It can be expressed as a rotation angle curve for the attachment section.

In addition, the manager terminal 140, as shown in FIG. 8, is represented by a displacement curve for the inclinometer (110a ~ 110n) attachment section for each measurement time slot, and the displacement history of any point within the inclinometer attachment section for each measurement time slot. It can be converted to .

Specifically, the data collection unit 141 of the manager terminal 140 wirelessly collects the rotation angle signal collected by the data logger 120 via the communication module 130.

As shown in FIG. 7, the rotation angle curve selection unit 142 of the manager terminal 140 selects a rotation angle curve suitable for the characteristics of the structure according to the collected rotation angle signal.

As shown in FIG. 8, the displacement curve determination unit 143 of the manager terminal 140 determines the displacement curve of the structure due to external force by integrating the selected rotation angle curve once.

The signal processing unit 144 of the manager terminal 140 processes signals to filter displacement in a specific band. For example, displacement in a specific band can be filtered through a low-pass filter.

The static and dynamic displacement determination unit 145 determines the static displacement and dynamic displacement of any part of the structure 200 separately.

When the structure 200 is a bridge, the impact coefficient calculation unit 146 calculates the impact effect when the vehicle 300 is driven according to the static displacement and dynamic displacement of the vehicle 300 measured at any part of the structure 200. The impact coefficient, which is the coefficient represented, is calculated for a random part. Accordingly, the load-bearing capacity of the structure 200 can be easily evaluated.

The management DB 147 stores data collected and generated by the manager terminal 140.

In other words, in the case of the structure displacement measurement system 100 through rotation angle measurement and signal processing according to an embodiment of the present invention, the rotation angle signal measured at a specific part of the structure 200 using the inclinometers 110a to 110n Through this, the static and dynamic displacement of any part of the structure 200 can be measured.

For example, it is possible to measure displacement caused by external forces of horizontal and vertical structures, such as vertical deflection caused by bridge vehicles or horizontal displacement caused by wind in wind towers.

Specifically, an inclinometer capable of collecting precise rotation angles is attached to a specific part of the structure 200, and after measuring the rotation angle signal according to the external force, a rotation angle curve suitable for the characteristics of the structure is selected and the rotation angle curve is integrated once. By finding the displacement of a structure due to an external force, the displacement can be measured through a signal processing process that filters the displacement in a specific band.

At this time, a rotation angle curve corresponding to the rotation angle signal received from the inclinometers 110a to 110n attached at least 5 locations can be selected.

In addition, the rotation angle curve is numerically integrated once to convert the received rotation angle signal into the displacement of the structure 200, and the displacement of the structure is calculated as a mixture of static displacement and dynamic displacement due to external force.

Specifically, in the case of the structural displacement measurement system 100 through rotation angle measurement and signal processing according to an embodiment of the present invention, the rotation angle is measured using high-resolution inclinometers (110a to 110n) with a large sampling frequency, and signal processing is used to statically measure the displacement. Deflection and dynamic deflection can be extracted.

At this time, in order to obtain dynamic displacement that includes the impact effect due to vehicle movement, the inclinometer used for measurement must have a high sampling frequency standard. For example, in the case of bridges, an inclinometer for accurate static and dynamic displacement measurement is required. It is desirable to use a sampling frequency of 20Hz or more as the required standard.

In addition, in the case of the structure displacement measurement system 100 through rotation angle measurement and signal processing according to an embodiment of the present invention, the deflection of the bridge can be measured with a small error even with five or more inclinometers 110a to 110n by cubic spline interpolation. Accurate deflection can be measured.

In other words, the rotation angle between the two measured inclinometers is interpolated with a cubic spline curve and converted into displacement through one-time numerical integration, and the phenomenon of the converted displacement diverging to unrealistic values is corrected to provide accurate static and dynamic displacements. A series of signal processing processes to distinguish can be performed automatically.

In addition, the structural displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention can accurately measure deflection with at least five inclinometers in order to measure deflection of all types of bridges, including suspension bridges.

In the end, according to the structure displacement measurement system through rotation angle measurement and signal processing according to an embodiment of the present invention, the displacement is calculated by integrating the rotation angle measured by the inclinometer once so that the displacement can be measured only with an inclinometer, thereby eliminating the pushing phenomenon. There is no drift, and as a result, the displacement of the structure can be measured with little error from the actual value.

In addition, the number of measurement sensors can be significantly reduced by installing at least five inclinometers of one type to measure displacement at arbitrary locations in the structure.

In addition, by calculating the displacement by integrating the rotation angle data measured by the inclinometer installed on the structure once, the displacement error is small, and by measuring both static and dynamic displacement, it can be used for impact coefficient selection and load testing.

[Method for measuring structural displacement through rotation angle measurement and signal processing]

Figure 9 is an operation flowchart showing a method of measuring structural displacement through rotation angle measurement and signal processing according to an embodiment of the present invention.

Referring to Figures 5 and 9, the method of measuring structural displacement through rotation angle measurement and signal processing according to an embodiment of the present invention first uses at least five or more rotation angles capable of collecting precise rotation angles in a specific part of the structure 200. Attach and install the inclinometers (110a to 110n) (S110).

Here, the inclinometers (110a ~ 110n) each measure the rotation angle signal at a sampling rate of 20 Hz or more, and the inclinometers (110a ~ 110n) are attached at predetermined intervals to at least five specific parts of the structure 200. You can.

Next, each of the at least five inclinometers 110a to 110n measures a rotation angle signal according to an external force (S120).

Next, the manager terminal 140 collects the rotation angle signal and selects a rotation angle curve suitable for the characteristics of the structure 200 (S130).

Here, in order to select a geometric displacement curve that matches the characteristics of the structure 200, a rotation angle curve corresponding to the rotation angle signals received from each of the inclinometers 110a to 110n attached to the five or more locations can be selected. there is.

Next, the manager terminal 140 integrates the selected rotation angle curve once to determine the displacement curve of the structure 200 due to external force (S140).

At this time, in order to minimize the increase in rotation angle error and ensure stability in the numerical integration process of converting to displacement, it is desirable to interpolate the rotation angle between the two inclinometers with a cubic spline curve.

Next, the manager terminal 140 processes a signal to filter the displacement of a specific band (S150).

Here, in order to convert the received rotation angle signal into a displacement of an arbitrary part of the structure 200, the rotation angle signal data is numerically integrated once, and the structure 200 is a mixture of static displacement and dynamic displacement due to external force. ) can be calculated.

Next, the manager terminal 140 determines the static displacement and dynamic displacement of the entire structure 200 (S160).

Here, in the process of filtering the selected displacement, a specific frequency band can be selected, and through filtering by the selected specific frequency band, it can be separated into static displacement and dynamic displacement due to external force.

That is, the manager terminal 140 wirelessly receives the rotation angle signal and processes the signal to calculate the displacement for evaluating the load carrying capacity of the structure 200.

Next, for example, when the structure 200 is a bridge, the impact is a coefficient that represents the impact effect when the vehicle 300 is driven according to the static displacement and dynamic displacement caused by the vehicle measured at any part of the structure 200. Calculate the coefficient for a random part (S170).

Ultimately, according to an embodiment of the present invention, when it is difficult to install a measuring instrument necessary for measuring displacement, or when it is burdensome to install a displacement measuring instrument because the price of the measuring instrument itself is expensive, the displacement of the structure can be measured accurately at low cost regardless of the surrounding conditions. Values can be measured.

Additionally, in the case of highway bridges where traffic control is not possible, deflection can be measured without traffic control.

In addition, by combining the Internet of Things (IoT) technology, it can contribute to reducing the maintenance budget and securing a constant safety management environment by obtaining regular deflection data of highway bridges and replacing load-bearing capacity assessments.

In addition, static and dynamic deflections are used to calculate the impact coefficient when evaluating the load-bearing capacity of a bridge, so load-bearing capacity can be evaluated without traffic control.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

100: Structure displacement measurement system 200: Structure
300: vehicle 110, 110a~110n: inclinometer
120: data logger 130: communication module
140: Administrator terminal 141: Data collection unit
142: rotation angle curve selection unit 143: displacement curve determination unit
144: signal processing unit 145: static and dynamic displacement determination unit
146: Impact coefficient calculation unit 147: Management DB

Claims (10)

In the structure displacement measurement system through rotation angle measurement and signal processing that calculates the displacement for evaluating the load-bearing capacity of the structure 200, the displacement calculated for evaluating the load-bearing capacity of the structure 200 is,
A rotation angle signal collected according to an external force is received from the inclinometers (110a to 110n) attached to the structure 200, and the received rotation angle signal is expressed as a rotation angle history of the attachment point of the inclinometers (110a to 110n) over time, It is expressed as a rotation angle curve for the attachment section of the inclinometer (110a ~ 110n) for each measurement time zone, and the rotation angle curve is represented as a displacement curve for the attachment section of the inclinometer (110a ~ 110n) for each measurement time zone, and the inclinometer attachment section for each measurement time zone. It is calculated by converting it into the displacement history of an arbitrary point within it,
A data logger 120 that is attached to the structure 200 to enable rotation angle collection and collects rotation angle signals measured from each of the inclinometers 110a to 110n that measure rotation angle signals according to external forces; And receiving the rotation angle signal wirelessly from the communication module 130, which wirelessly transmits the rotation angle signal collected by the data logger 120, and processing the signal to calculate the displacement for evaluating the load carrying capacity of the structure 200. A manager terminal 140; wherein the manager terminal 140 displays the received rotation angle signal as a rotation angle history of the attachment point of the inclinometers 110a to 110n over time, and the inclinometer 110a for each measurement time period. ~110n) It is expressed as a rotation angle curve for the attachment section, and it is expressed as a displacement curve for the attachment point of the inclinometer (110a to 110n) for each measurement time period, and is converted into the displacement history of the inclinometer attachment section for each measurement time period, and the structure 200 The signal is processed to calculate the displacement for load-bearing capacity evaluation, and the manager terminal 140 is a data collection unit 141 that collects the rotation angle signal collected by the data logger 120 via the communication module 130. ); a rotation angle curve selection unit 142 that selects a rotation angle curve suitable for the characteristics of the structure according to the collected rotation angle signal; A displacement curve determination unit 143 that determines a displacement curve of the structure 200 due to an external force by integrating the selected rotation angle curve once; A signal processing unit 144 that processes signals to filter displacement in a specific band; And a structure displacement measurement system through rotation angle measurement and signal processing that includes a static and dynamic displacement determination unit 145 that determines the static displacement and dynamic displacement of the entire structure 200, respectively. delete delete According to paragraph 1,
The inclinometers (110a to 110n) are,
The rotation angle signal is measured at a sampling rate of 20 Hz or more, and the inclinometers 110a to 110n are attached to specific parts of the structure 200 at predetermined intervals. Rotation angle measurement and signal processing Structure displacement measurement system through. delete According to paragraph 1,
The manager terminal 140,
When the structure 200 is a bridge, an impact coefficient is calculated for a random part when the vehicle 300 is driven according to the static displacement and dynamic displacement by the vehicle 300 measured at a random part of the structure 200. A structural displacement measurement system through rotation angle measurement and signal processing that additionally includes a calculation unit 146. a) attaching and installing inclinometers (110a to 110n) capable of collecting rotation angles on the structure 200;
b) each of the inclinometers (110a to 110n) measuring a rotation angle signal according to an external force;
c) the manager terminal 140 collecting the rotation angle signal and selecting a rotation angle curve suitable for the characteristics of the structure 200;
d) the manager terminal 140 determining a displacement curve of the structure 200 due to an external force by integrating the selected rotation angle curve once;
e) the manager terminal 140 processing a signal to filter displacement in a specific band; and
f) the manager terminal 140 determining the static displacement and dynamic displacement of any part of the structure 200, respectively;
The manager terminal 140 wirelessly receives a rotation angle signal and processes the signal to calculate a displacement for evaluating the load carrying capacity of the structure 200. A structure displacement measurement method through rotation angle measurement and signal processing. In clause 7,
In step c), a rotation angle curve corresponding to the received rotation angle signals is selected to select a geometric displacement curve that matches the characteristics of the structure 200 through rotation angle measurement and signal processing. Method for measuring structural displacement. In clause 7,
In order to minimize the increase in rotation angle error in step d) and ensure stability in the numerical integration process of converting to displacement, the rotation angle between the two inclinometers is interpolated with a cubic spline curve, respectively. Method of measuring structural displacement through each measurement and signal processing. In clause 7,
In order to convert the received rotation angle signal into a displacement of an arbitrary part of the structure 200, the rotation angle signal data is numerically integrated once, and the static displacement and dynamic displacement due to external force are mixed. Calculate the displacement,
In step e), a specific frequency band is selected in the process of filtering the selected displacement, and the rotation angle is separated into static displacement and dynamic displacement due to external force through filtering by the selected specific frequency band. Method for measuring structural displacement through measurement and signal processing.