JP2020067418A - Bridge evaluation system and bridge evaluation method - Google Patents

Abstract

To accurately determine the state of a bridge.SOLUTION: A bridge evaluation system according to one embodiment includes: an acquisition unit which acquires image data obtained by imaging an object passing through a bridge; and a determination unit which determines the state of the bridge on the basis of the image data. The determination unit (A) calculates the weight of the object at each of one or more measurement points of the bridge and a reference point of the bridge by analyzing the image data, (B) calculates the ratio of the weight at the measurement point to the weight at the reference point as the relative weight for each of one or more measurement points, and (C) determines the state of the bridge on the basis of the relative weight of each of one or more measurement points.SELECTED DRAWING: Figure 1

Description

  One aspect of the present disclosure relates to a bridge evaluation system and a bridge evaluation method.

  A method for evaluating the condition of a bridge is conventionally known. For example, Patent Document 1 describes a rigidity measuring device that measures the rigidity distribution of a measurement target. This device includes a displacement calculator, a load estimator, and a rigidity calculator. The displacement calculation unit uses a plurality of captured images of the measurement target captured at a plurality of times to calculate a displacement distribution indicating a spatial displacement over time for each of the plurality of measurement points set as the measurement target. To do. The load estimation unit estimates the load distribution indicating the spatial distribution of the load applied to the measurement target over time using the plurality of captured images. The rigidity calculation unit calculates the rigidity distribution of the measurement target using the displacement distribution and the load distribution.

Japanese Patent No. 6322817

  However, since it is difficult to accurately estimate the load (external force) applied to the bridge, it is difficult to evaluate the state of the bridge with the above technique that assumes load distribution. Therefore, it is desired to accurately determine the condition of the bridge.

  A bridge evaluation system according to one aspect of the present disclosure includes an acquisition unit that acquires image data obtained by capturing an image of an object passing through a bridge, and a determination unit that determines the state of the bridge based on the image data. By analyzing the image data, the weight of the object at each of the one or more measurement points of the bridge and the reference point of the bridge is calculated, and the weight at the measurement point and the reference point are calculated for each of the one or more measurement points. Is calculated as a relative weight, and the state of the bridge is determined based on the relative weight of each of the one or more measurement points.

  A bridge evaluation method according to an aspect of the present disclosure is a bridge evaluation method executed by a computer system, and includes an acquisition step of acquiring image data of an object passing through the bridge, and a state of the bridge based on the image data. A determination step for determining the weight of the object at each of the one or more measurement points of the bridge and the reference point of the bridge by analyzing the image data; For each of the measurement points, a substep of calculating the ratio of the weight at the measurement point to the weight at the reference point as a relative weight, and determining the state of the bridge based on the relative weight of each of the one or more measurement points And substeps.

  In such a side surface, the weight of the object at each measurement point of the bridge is converted into a relative value using the weight of the object at the reference point, and the state of the bridge is determined based on the relative value. With this method, it becomes possible to accurately determine the state of the bridge without accurately obtaining the load itself applied to the bridge.

  According to one aspect of the present disclosure, it is possible to accurately determine the state of a bridge.

It is a figure showing an example of functional composition of a bridge evaluation system concerning an embodiment. It is a flow chart which shows an example of operation of the bridge evaluation system in an embodiment. It is a figure which shows an example regarding the displacement of a bridge, and an object weight. It is a flow chart which shows an example of operation of the bridge evaluation system in an embodiment. It is a figure which shows an example of the relative weight distribution of a bridge. It is a figure which shows an example of the method of determining the state of a bridge. It is a flow chart which shows an example of operation of the bridge evaluation system in an embodiment. It is a figure which shows an example of the hardware constitutions of the computer used for the bridge evaluation system which concerns on embodiment.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference symbols, without redundant description.

  The bridge evaluation system 10 according to the embodiment is a computer system that determines the state of a bridge. The bridge evaluation system 10 can determine a condition for each of the one or more bridges.

  A bridge is a structure that supports passages made without closing subspaces such as rivers, valleys, straits, and other passages. This passage may function as at least one of a traffic route and a transportation route, and may function as, for example, a road, a railroad, a waterway, or a sidewalk. Examples of bridges include road bridges, aqueducts, overpasses, railway bridges, and pedestrian bridges, but the types of bridges are not limited in any way.

  The state of a bridge is the state of the bridge that changes over time. For example, the condition of the bridge may be the degree of deterioration of the bridge. Deterioration of a bridge means that the quality or performance of the bridge is impaired over time. The fact that the bridge is not deteriorated means that the bridge is healthy (that is, the quality or performance of the bridge is maintained). Therefore, it can be said that determining whether or not the bridge is deteriorated is substantially the same as determining whether or not the bridge is healthy.

  The bridge evaluation system 10 acquires image data of a scene in which a certain object passes through the bridge, and determines the state of the bridge based on the image data. Specifically, the bridge evaluation system 10 sets a plurality of measurement points on the bridge reflected in the image data. Then, the bridge evaluation system 10 calculates the weight of the object at each measurement point (hereinafter also referred to as “object weight”) by analyzing the image data. The bridge evaluation system 10 converts the object weight at each measurement point into a relative weight, and determines the state of the bridge based on the relative weight. The object passing through the bridge is not limited and may be, for example, a car, a bicycle, a train, a ship, an air vehicle, or a person. The object may pass through the bridge while riding on the bridge, or may pass through the bridge while hanging on the bridge.

  FIG. 1 is a diagram showing an example of a functional configuration of a bridge evaluation system 10 and an example of a bridge. The bridge evaluation system 10 includes an acquisition unit 11, a determination unit 12, and an output unit 13 as functional elements.

  The acquisition unit 11 is a functional element that acquires image data of an object that passes through a bridge. The image data is data indicating an image that can be visually recognized by being processed by a computer. The format of the image is not limited as long as the weight of the object can be calculated. For example, the image may be a moving image, a set of a plurality of still images obtained by continuous shooting, or a set of a plurality of still images extracted from the moving image. The acquisition unit 11 may extract still images of a plurality of frames from the moving image. The acquisition unit 11 acquires image data of an image of at least a part of the bridge, and more specifically, acquires image data of an image of the part of the bridge necessary for determining the state of the bridge. For example, the acquisition unit 11 acquires image data of the entire bridge or almost the entire bridge.

  The determination unit 12 is a functional element that determines the state of the bridge by analyzing the image data acquired by the acquisition unit 11. The determination unit 12 sets a plurality of measurement points on the bridge shown in the image data and calculates the object weight at each measurement point. The determination unit 12 also selects one reference point from the plurality of measurement points. The determination unit 12 obtains the relative weight at each measurement point and determines the state of the bridge based on the plurality of relative weights. In the present disclosure, the relative weight refers to the ratio of the object weight at the measurement point to the object weight at the reference point.

  FIG. 1 illustrates a scene in which the bridge evaluation system 10 sets a plurality of measurement points 80a on one side or one side of a bridge girder of the bridge 80 and determines the state based on the relative weight of the object 90 at each measurement point 80a. . The location of each measurement point is not limited and may be determined based on any policy. FIG. 1 shows a vehicle as an example of an object 90.

  The output unit 13 is a functional element that outputs the determination result obtained by the determination unit 12. The method of expressing the determination result is not limited. For example, the determination result may be expressed in two stages of “deteriorated” and “not deteriorated”, or “no deterioration” “deterioration degree = low” “deterioration degree = medium” “deterioration degree = high”. May be expressed in three or more levels. Alternatively, the determination result may be expressed by an arbitrary index, for example, a difference between the average values of two relative weight distributions described later. Alternatively, the determination result may be expressed using a graph or a graphic. In any case, the user of the bridge evaluation system 10 can confirm the state of the bridge by referring to the determination result, and can further determine whether or not the bridge should be reinforced or modified.

  As shown in FIG. 1, the image data of the object 90 passing through the bridge 80 is obtained by the camera 20. The camera 20 is an imaging device that images a space including a bridge to generate image data. The camera 20 may be constructed as a part of the bridge evaluation system 10 or may be constructed as a component separate from the bridge evaluation system 10. The camera 20 may be integrated with a computer forming the bridge evaluation system 10. The camera 20 may be fixedly installed at a position where an image of the bridge can be captured, or may be brought to an observation position by a person each time the image is captured if fixed-point observation is possible. The camera 20 has a function of generating an image with a resolution that allows displacement of the bridge to be detected. The image data is sent from the camera 20 to the image database 21 via the communication network or the recording medium and stored in the image database 21. Examples of the communication network include a mobile communication network, the Internet, and WAN (Wide Area Network). Examples of the recording medium include SD memory card and USB memory. However, the communication network and the recording medium are not limited to these, and any method may be adopted.

  The image database 21 is a device (storage unit) that temporarily or permanently stores image data. The image database 21 may be constructed as a part of the bridge evaluation system 10 or may be constructed as a component separate from the bridge evaluation system 10. The acquisition unit 11 can access the image database 21 and read the image data. The image database 21 is not an essential component, and the bridge evaluation system 10 may receive image data directly from the camera 20.

  In one example, the image data of the bridge is associated with the shooting date and time. Alternatively, the image data may be associated with a bridge ID that is an identifier that uniquely identifies the bridge. Alternatively, the image data may be associated with both the bridge ID and the shooting date and time.

  As shown in FIG. 1, in one example, a weight database 22 may be used. The weight database 22 is a device (storage unit) that temporarily or permanently stores data regarding the relative weight calculated by the bridge evaluation system 10. The weight database 22 may be constructed as a part of the bridge evaluation system 10 or may be constructed as a computer system different from the bridge evaluation system 10. In one example, the determination unit 12 accesses the weight database 22 to store data regarding the relative weight in the weight database 22 or read the data to determine the state of the bridge.

  In one example, the relative weight data may be associated with the shooting date and time. Alternatively, the relative weight data may be associated with the bridge ID. Alternatively, the relative weight data may be associated with both the bridge ID and the shooting date and time.

  The specific processing procedure for determining the state of the bridge is not limited. Hereinafter, some examples of the determination will be described.

  An example of processing for determining the state of the bridge based on the relative weight distribution will be described with reference to FIGS. 2 to 6. The relative weight distribution is data indicating the frequency of appearance of the relative weight at each stage within a limited period. FIG. 2 is a flowchart showing an example of a process for generating the relative weight distribution as a process flow S1. FIG. 3 is a diagram showing an example of the displacement of the bridge and the weight of the object. FIG. 4 is a flowchart showing an example of the determination process using the relative weight distribution as a process flow S2. FIG. 5 is a diagram showing an example of the relative weight distribution. FIG. 6 is a diagram showing an example of a method for determining the state of the bridge. Both FIG. 2 and FIG. 4 show the processing for one bridge.

  The bridge evaluation system 10 generates a relative weight distribution in one observation period. The observation period refers to the length of time during which it is estimated that the condition of the bridge will hardly change, in other words, the period during which the deterioration of the bridge will not proceed. Therefore, it can be said that the observation period is much shorter than the service life of the bridge. The specific length of the observation period is not limited, and may be set according to the type and characteristics of the bridge, for example. For example, the length of the observation period may be hours, days, weeks, months, or a year. The bridge evaluation system 10 can obtain the relative weight distribution for each of the plurality of measurement points by calculating the relative weight at each of the plurality of measurement points in one observation period. Considering the life of the bridge, the relative weight distribution in one observation period can be said to be the result of monitoring the bridge at a certain point in time.

  In step S101, the determination unit 12 sets one observation period. The start point and the end point of the observation period may be set arbitrarily.

  In step S102, the determination unit 12 sets one measurement time point within the observation period. The time of measurement means the time when the bridge is displaced once. For example, when determining the state of a bridge, the measurement time point is the time during which a certain object is passing through the bridge. It should be noted that while the one object is passing through the bridge, another object is not prevented from passing through the bridge.

  In step S103, the acquisition unit 11 acquires image data corresponding to the measurement time point. The method of acquiring image data is not limited. For example, the acquisition unit 11 may acquire the image data from the image database 21 or may directly receive the image data from the camera 20. In one example, the acquisition unit 11 may extract only the portion necessary for calculating the object weight from the image data. The "portion necessary for calculating the object weight" may be a moving image for a certain time width, or may be a set of a plurality of still images continuously shot in the time width. The acquisition unit 11 extracts, from the image data, only a portion of a scene where one object passes. When the object is a vehicle, the displacement of the bridge increases as the weight of the passing vehicle increases, and it can be expected that the object weight can be obtained more accurately from the image data. Therefore, the acquisition unit 11 may extract from the image only a portion of a scene in which one large vehicle such as a truck passes. The acquisition unit 11 may estimate the position of the object (the position of the object on the bridge) necessary for BWIM described later. If the object is a vehicle, the total weight of the axles is obtained as the weight of the vehicle, so the acquisition unit 11 may estimate the position of each axle of the vehicle. The acquisition unit 11 can automatically extract, from image data, a screen in which one object passes through a bridge by using a known technique of detecting or estimating an object from an image. Examples of such known techniques include template matching and deep learning, but techniques for detecting or estimating an object are not limited to these. Techniques such as template matching and deep learning can also be used to estimate the position of the object. The process of extracting such a specific scene from the image data is not essential, and the process of estimating the position of the object is not essential. For example, the image data extracted by manual processing may be stored in the image database 21 in advance, and the acquisition unit 11 may acquire the edited image data. The position of the object may be estimated by manual processing.

  In step S104, the determination unit 12 sets a plurality of measurement points for the bridge shown in the image data. The method of setting the measurement points is not limited, and may be set in consideration of, for example, the type, shape and characteristics of the bridge. For example, as shown in FIG. 1, the determination unit 12 sets a plurality of measurement points 80a on the bridge 80. The distance between adjacent measurement points may be set arbitrarily, for example, the measurement points may be set at equal intervals, or the distance between the measurement points may be different.

  In step S105, the determination unit 12 calculates the displacement of each of the plurality of measurement points. In the present disclosure, the displacement means the amount of movement of the measurement point set on the bridge when the measurement point is deformed by receiving a load. The determination unit 12 calculates the transition of the displacement of each measurement point that occurs while one object passes through the bridge. The change in displacement refers to a change in displacement that occurs over time. The determination unit 12 can calculate the displacement transition by analyzing the image data using a known technique such as a block matching method or a digital image correlation method. The block matching method is a method in which one of two images is divided into a plurality of blocks, and a displacement is obtained by searching each block for a corresponding position on the other image. The digital image correlation method is a method of obtaining displacement by comparing the positions of specific random patterns between two images. The determination unit 12 may obtain a static change of the measurement point by removing the vibration component by applying a low-pass filter to the obtained displacement transition. In this case, it can be said that the displacement before applying the low-pass filter is a temporary displacement, and the value obtained by applying the low-pass filter is the displacement to be obtained. By using the low-pass filter, the transition of displacement can be obtained more accurately, and thus the object weight and the relative weight can be obtained more accurately.

  In step S106, the determination unit 12 calculates the object weight at each measurement point based on the calculated displacement. Specifically, the determination unit 12 calculates the object weight from the transition of the displacement at each measurement point, using a method called BWIM (Bridge Weight-In-Motion).

  BWIM is a technique for measuring the weight of an object such as a vehicle by simulating a bridge as a scale and analyzing a strain response or a flexural response generated in a bridge member such as a bridge girder. When the BWIM is used, first, a strain response or a deflection response at a measurement point is measured by passing a first object (for example, a vehicle) whose weight is known through a bridge, and an influence line is calculated. Then, the theoretical value of strain or deflection is calculated based on the influence line and the load of the first object (for example, the axial load in the case of a vehicle). After that, when a second object of unknown weight (for example, a vehicle) passes through the bridge and a measured value of strain or deflection is obtained, the weight of the second object is minimized so that the difference between the theoretical value and the measured value is minimized. Is calculated.

Using the BWIM, the determination unit 12 can calculate the object weight for each measurement point from the calculated displacement transition (that is, strain response or flexure response). Details of the BWIM based on the flexural response are described in Reference 1 below, for example.
(Reference 1) Hidehiko Sekiya, 3 others, "Proposal of Portable-Weight-In-Motion System Based on Displacement Measurement Using MEMS Accelerometer", Proceedings of JSCE A1 (Structural / Earthquake Engineering), 2016, Volume 72, Issue 3, p. 364-379

  If the weight of the first object is known, the determination unit 12 can also estimate the weight of each second object that has passed through the bridge determined to be sound. However, even if the weight of the first object is unknown, the determination unit 12 sets the weight of the first object as one unit weight to obtain the weight of the second object as a relative value with respect to the unit weight. You can

FIG. 3 shows an example of the calculated object weight, and more specifically, shows the object weight at the five measurement points 81 to 85 set on the bridge 80. FIG. 3 shows that the measurement point 81 was displaced by x ₁ when the object passed through the bridge 80, and the object weight at the measurement point 81 was calculated as w ₁ from the transition of the displacement including the instantaneous value thereof. . FIG. 3 further shows that, like the measurement point 81, the object weights at the measurement points 82, 83, 84 and 85 were calculated as w ₂ , w ₃ , w ₄ and w ₅ , respectively. In the example of FIG. 3, the determination unit 12 obtains the object weights w ₁ , w ₂ , w ₃ , w ₄ , w ₅ for a certain object, so these five object weights should originally be equal.

In step S107, the determination unit 12 selects one reference point from the plurality of measurement points. The method of selecting the reference point is not limited, and any method may be used. For example, the determination unit 12 may select the measurement point having the largest calculated displacement as the reference point. It can be expected that the larger the displacement, the smaller the error rate. Therefore, by using the measurement point at which the maximum displacement is recorded as the reference point, it is possible to reduce the error in the relative weight and thus to accurately determine the state of the bridge. In the example of FIG. 3, since the displacement x ₃ is the largest, the determination unit 12 may select the measurement point 83 as the reference point.

In step S108, the determination unit 12 calculates the relative weight of each of the plurality of measurement points. As described above, this relative weight is the ratio of the object weight at the measurement point to the object weight at the reference point. The determination unit 12 may set a value obtained by dividing the object weight at the reference point by the object weight at the measurement point as the relative weight, or a value obtained by dividing the object weight at the measurement point by the object weight at the reference point. May be set as the relative weight. When the measurement point 83 is selected as the reference point in the example of FIG. 3, the determination unit 12 determines the relative weights of the measurement points 81, 82, 83, 84, and 85 as w ₃ / w ₁ and w ₃ / w, respectively. _It may be calculated as ₂ , w ₃ / w ₃ , w ₃ / w ₄ , w ₃ / w ₅ . The relative weight of the measuring point selected as the reference point is always 1. As described above, since the object weights w ₁ , w ₂ , w ₃ , w ₄ , w ₅ should theoretically be the same for one object, the relative weight of each measurement point should originally be 1. is there.

  As shown in step S109, when there is another measurement time point to be processed within one observation period, the process proceeds to step S110, and the determination unit 12 determines the next measurement time point within the observation period. Set. After that, the processes of steps S103 to S108 are executed at the measurement time point. On the other hand, when the relative weights have been calculated for all the measurement points within the observation period, the process proceeds to step S111.

  In step S111, the determination part 12 produces | generates the relative weight distribution in one observation period about each measurement point. However, since the relative weight of the reference point is always 1, it is sufficient for the determination unit 12 to obtain the relative weight distribution for each measurement point other than the reference point. The determination unit 12 may store the generated data indicating the relative weight distribution in the weight database 22. The relative weight distribution data may be represented by a set of individual relative weights at individual measurement points. When the relative weight distribution can be approximated by a normal distribution, the relative weight distribution data at each measurement point may be represented by an average value, an unbiased variance, and a sample size.

  The bridge evaluation system 10 generates the relative weight distribution for each observation period by executing the processing flow S1 in each of the plurality of observation periods. The bridge evaluation system 10 may periodically execute the processing flow S1. For example, the bridge evaluation system 10 may acquire the relative weight distribution every day when the observation period is several hours, may be acquired every month when the observation period is several weeks, and may be acquired when the observation period is one year. You may get it every year. The bridge evaluation system 10 obtains the relative weight distribution without changing the positions of the plurality of measurement points and the reference points in each observation period, and thereby can accurately grasp the change of the bridge over time.

  The bridge evaluation system 10 executes the process flow S2 at an arbitrary timing after obtaining the relative weight distributions for a plurality of observation periods.

  In step S201, the determination unit 12 acquires the relative weight distribution in the reference period as the first relative weight distribution from the weight database 22. In step S202, the determination unit 12 acquires the relative weight distribution during the inspection period as the second relative weight distribution from the weight database 22. The first relative weight distribution is generated from the image data (first image data) of the bridge during the reference period, and the second relative weight distribution is generated from the image data (second image data) of the bridge during the inspection period. It is a thing. The reference period refers to the observation period that serves as the reference for determining the condition of the bridge, and the inspection period refers to the observation period for which you want to know the condition of the bridge. The reference period and the inspection period may be set arbitrarily, and may be specified by the user of the bridge evaluation system 10, for example. As an example, the reference period may be a period set at a time when the bridge is known to be healthy. For example, the reference period may correspond to the period immediately after the bridge is constructed, or may correspond to the period after the periodic inspection of the bridge is completed.

  In step S203, the determination unit 12 determines the state of the bridge by comparing the relative weight distributions of both the reference period and the inspection period. The specific determination method is not limited, and the determination unit 12 can use any method.

  As an example, the determination unit 12 may determine the state of the bridge by obtaining an average value of the relative weight distribution for each of the reference period and the inspection period and comparing the average values of the two. For example, the determination unit 12 can determine that the bridge is deteriorated if there is a significant difference between the two average values, and can determine that the bridge is not deteriorated if there is no significant difference. Alternatively, the determination unit 12 may set the difference between the two average values as the determination result.

  As shown in each graph of FIG. 5, for each of the measurement points 81, 82, 84, 85 of the bridge 80 (excluding the measurement point 83, which is the reference point), the relative weight distribution 31 of the reference period and the relative weight of the inspection period. It is assumed that the distribution 32 and is obtained. Here, the horizontal axis of the graph represents the relative weight, which is a random variable, and the vertical axis represents the probability density. If there is no significant difference in the average value of these two relative weight distributions, the condition of the bridge 80 during the inspection period is almost the same as that during the reference period, and therefore it is determined that the bridge 80 has not deteriorated. You can On the other hand, when there is a significant difference in the average value of these two relative weight distributions, it can be said that the state of the bridge 80 has changed significantly with the passage of time from the reference period to the inspection period. It can be determined that there is. As an example, if the value obtained by dividing the object weight at the reference point where the displacement is largest by the object weight at the measurement point is set as the relative weight, the average value of the relative weight distribution in the reference period It can be said that there is a high probability that the vicinity of the measurement point where the average value of the relative weight distribution is small is deteriorated. As described above, the determination unit 12 may set the difference in the average value between the reference period and the inspection period for at least one measurement point as the determination result.

  The determination unit 12 may verify whether or not there is a significant difference between the two average values by using Welch's t-test. Welch's t-test is a method of testing whether the means of two populations are equal. By using this method, it is possible to compare the average values of the two periods even when the sample size differs between the reference period and the inspection period. For example, even when the number of measurement time points is different between the two periods because the time lengths of the reference period and the inspection period are different, the average values can be appropriately compared. As a result, it is possible to accurately estimate the change in the bridge with the passage from the reference period to the inspection period. Therefore, in one example, the time length may be different between the reference period and the inspection period, or the number of measurement time points may be different in both periods.

ここで、

は第１の母集団の標本平均であり、

は第２の母集団の標本平均である。ｓ_１ ^２は第１の母集団の不偏分散であり、ｓ_２ ^２は第２の母集団の不偏分散である。ｎ_１は第１の母集団のサンプルサイズであり、ｎ_２は第２の母集団のサンプルサイズである。 In Welch's t-test, the statistic t is defined by the following equation (1).

here,

Is the sample mean of the first population,

Is the sample mean of the second population. s ₁ ² is the unbiased variance of the first population and s ₂ ² is the unbiased variance of the second population. n ₁ is the sample size of the first population and n ₂ is the sample size of the second population.

The degree of freedom ν is defined by the following equation (2).

  If the Welch's t-test is used as it is, the determination unit 12 may determine that the bridge has deteriorated even if the difference between the average values is small. In order to grasp a change that affects the performance of the bridge, the determination unit 12 changes the average value (first average value) of the relative weight distribution in the reference period by a given amount, and then Welch's t-test. May be executed. The amount of change in the first average value may be set on an arbitrary basis. For example, the amount of change may be set based on a criterion of how much the condition of the bridge is changed before the bridge is considered to be deteriorated.

を加えてもよい。 More specifically, the amount of change may be set based on the rate α at which the relative weight changes. When this ratio α is used, the determination unit 12 changes the first average value by (1-α) times, and then the average value (second average value) of the relative weight distribution during the inspection period is changed. It is tested whether or not the alternative hypothesis that it is smaller than the first average value holds. Further, the determination unit 12 changes the first average value by (1 + α) times and then tests whether or not the alternative hypothesis that the second average value is larger than the changed first average value holds. . The determination unit 12 executes these two one-sided tests, determines that the bridge is deteriorated if either of the two alternative hypotheses holds, and if neither alternative hypothesis holds, the bridge deteriorates. You may decide not to. For example, when the ratio α is set to 0.1, the determination unit 12 determines that the average value of the relative weight distribution of the bridge changes by more than 10% from the reference period to the inspection period. It is determined that the state has changed significantly (for example, it is determined that the bridge has deteriorated). The determination unit 12, a first average value, instead of (1 ± alpha) multiplied, in all samples x _s of the reference period

May be added.

  FIG. 6 shows an example of Welch's t-test using the ratio α. In this figure, after changing the average value (first average value) of the relative weight distribution 41 in the reference period by (1-α) times, the average value (second average value) of the relative weight distribution 42 in the inspection period. An example in which is compared with the first average value after the change is shown. In this example, since the second average value is smaller than the changed first average value, the alternative hypothesis holds. Therefore, the determination unit 12 determines that the bridge is deteriorated.

When the ratio α is used, the determination unit 12 obtains the two statistics t ₁ and t ₂ by the following equations (3) and (4).

  The determination unit 12 executes the two one-sided test for each measurement point other than the reference point by using the above-described method applying the Welch t-test. When there are two or more measurement points other than the reference point, the determination unit 12 determines the state of the bridge after comprehensively considering the test results at the individual measurement points using an arbitrary method. Good. For example, the determination unit 12 determines that the bridge is deteriorated when a significant difference occurs in the average value at at least one measurement point, and when the significant difference does not occur at any measurement point. It may be determined that the bridge has not deteriorated. Alternatively, the determining unit 12 determines that the bridge is deteriorated when a significant difference occurs in the average values at a plurality of measurement points, and the number of measurement points at which the significant difference occurs is 1 or less. In this case, it may be determined that the bridge has not deteriorated. Alternatively, the determination unit 12 determines that the bridge is deteriorated when a significant difference occurs in the average value at n (n> 1) or more measurement points, and the measurement point at which the significant difference occurs If the number is less than n, it may be determined that the bridge has not deteriorated. Alternatively, the determination unit 12 may set the difference between the changed first average value and the changed second average value for at least one measurement point as the determination result.

  In step S204, the output unit 13 outputs the determination result. The method of outputting the determination result is not limited. For example, the output unit 13 may store the determination result in a predetermined database, send it to another computer, or display it on a monitor.

  Step S103 is an example of an acquisition step, and steps S104 to S108 and S111 are an example of a determination step. Steps S201 to S203 are an example of determination steps. By the processing flows S1 and S2, the change of the relative weight with the passage of time is considered and the history is statistically processed, so that the state of the bridge can be accurately determined.

  When executing the process flows S1 and S2, the bridge evaluation system 10 does not have to store the relative weight distribution data in the weight database 22 once. For example, the bridge evaluation system 10 may generate the relative weight distribution for each of the reference period and the inspection period and then execute the processing flow S2 using the relative weight distribution without using the weight database 22.

  FIG. 7 is a flowchart showing an example of a process for determining the state of the bridge without using the relative weight distribution as a process flow S3.

  The processing of steps S301 to S306 is the same as the processing of steps S103 to S108 in the processing flow S1. In step S301, the acquisition unit 11 acquires image data corresponding to any one measurement time point. The acquisition unit 11 may extract only a portion necessary for measuring the object weight from the image data, or may obtain edited image data in which the portion is manually extracted. In step S302, the determination unit 12 sets a plurality of measurement points for the bridge shown in the image data. In step S303, the determination unit 12 analyzes the image data to calculate the displacements (more specifically, displacement transitions) of the plurality of measurement points. In step S304, the determination unit 12 calculates the object weight at each measurement point based on the calculated displacement. Specifically, the determination unit 12 uses BWIM to calculate the object weight from the displacement transition at each measurement point. In step S305, the determination unit 12 selects one reference point from the plurality of measurement points. In step S306, the determination unit 12 calculates the relative weight of each of the plurality of measurement points.

  In step S307, the determination unit 12 determines the state of the bridge by comparing the relative weights thereof with a given threshold value. The threshold setting method is not limited, and for example, the threshold may be a single value common to a plurality of measurement points, or may be set individually for each measurement point. The specific value of the threshold is not limited and may be set arbitrarily. Alternatively, the determination unit 12 may use the amount of change (for example, 10%) from the relative weight at the reference time point that is another measurement time point as the threshold value. This process is premised on that the bridge evaluation system 10 obtains the relative weight at the reference time point as the first relative weight by executing steps S301 to S306 for the image data corresponding to the reference time point. Then, the bridge evaluation system 10 obtains the relative weight at the time of inspection as the second relative weight by executing steps S301 to S306 for the image data corresponding to the time of inspection. The determination unit 12 determines the state of the bridge at the time of inspection by comparing the second relative weight with the first relative weight. For example, the determination unit 12 may determine that the bridge is deteriorated when the second relative weight changes from the first relative weight to a threshold value or more, and may determine that the bridge is not deteriorated otherwise. Good.

  The determination unit 12 determines that the bridge is deteriorated when the relative weight is equal to or more than the threshold value at at least one measurement point, and the bridge is deteriorated when the relative weight is less than the threshold value at any measurement point. You may decide not to. Alternatively, the determination unit 12 determines that the bridge is deteriorated when the relative weights are equal to or more than the threshold at a plurality of measurement points, and when the number of the measurement points whose relative weight is equal to or more than the threshold is 1 or less. May determine that the bridge has not deteriorated. Alternatively, the determination unit 12 determines that the bridge is deteriorated when the relative weight is equal to or greater than the threshold value at n (n> 1) or more measurement points, and the number of measurement points at which the relative weight is equal to or greater than the threshold value. When is less than n, it may be determined that the bridge has not deteriorated.

  In step S308, the output unit 13 outputs the determination result. This process is the same as step S204 in the process flow S2.

  Step S301 is an example of an acquisition step, and steps S302 to S307 are an example of a determination step. In the processing flow S3, the state of the bridge can be easily determined by using only the relative weight at one measurement time point. In addition, since it is not necessary to store the history of relative weights in a plurality of observation periods, it is possible to reduce the amount of storage devices such as databases and memories used.

  If the weight of the first object that serves as the basis of BWIM is known, the determination unit 12 may output the calculation result of the weight of each second object that has passed through the bridge determined to be sound.

  The block diagram used in the description of the above embodiment shows blocks of functional units. These functional blocks (components) are realized by an arbitrary combination of at least one of hardware and software. The method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device physically or logically coupled, or directly or indirectly (for example, two or more devices physically or logically separated). , Wired, wireless, etc.) and may be implemented using these multiple devices. The functional blocks may be realized by combining the one device or the plurality of devices with software.

  Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and observation. Broadcasting, notifying, communicating, forwarding, configuration, reconfiguring, allocating, mapping, assigning, etc., but not limited to these. I can't. For example, a functional block (component) that causes transmission to function is called a transmitting unit or a transmitter. In any case, as described above, the implementation method is not particularly limited.

  For example, the bridge evaluation system according to the embodiment of the present disclosure may function as a computer that performs the process of the wireless communication method of the present disclosure. FIG. 8 is a diagram illustrating an example of the hardware configuration of the computer 100 that functions as the bridge evaluation system 10. The computer 100 may physically include a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

  In the following description, the word "device" can be read as a circuit, a device, a unit, or the like. The hardware configuration of the bridge evaluation system 10 may be configured to include one or a plurality of each device illustrated in the figure, or may be configured not to include some devices.

  Each function in the bridge evaluation system 10 causes a predetermined software (program) to be loaded on hardware such as the processor 1001 and the memory 1002, so that the processor 1001 performs an operation and controls communication by the communication device 1004, and a memory. It is realized by controlling at least one of reading and writing of data in the storage 1002 and the storage 1003.

  The processor 1001 operates an operating system to control the entire computer, for example. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like.

  Further, the processor 1001 reads a program (program code), software module, data, and the like into the memory 1002 from at least one of the storage 1003 and the communication device 1004, and executes various processes according to these. As the program, a program that causes a computer to execute at least part of the operations described in the above-described embodiments is used. For example, each functional element of the bridge evaluation system 10 may be realized by a control program stored in the memory 1002 and operating in the processor 1001. Although it has been described that the various processes described above are executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via an electric communication line.

  The memory 1002 is a computer-readable recording medium, and is configured by at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), and the like. May be done. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store an executable program (program code), a software module, or the like for implementing the wireless communication method according to the embodiment of the present disclosure.

  The storage 1003 is a computer-readable recording medium, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray disc). At least one of a (registered trademark) disk, a smart card, a flash memory (for example, a card, a stick, and a key drive), a floppy (registered trademark) disk, a magnetic strip, or the like. The storage 1003 may be called an auxiliary storage device. The storage medium described above may be, for example, a database including at least one of the memory 1002 and the storage 1003, a server, or another appropriate medium.

  The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, and the like in order to realize at least one of frequency division duplex (FDD: Frequency Division Duplex) and time division duplex (TDD). May be composed of

  The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated (for example, a touch panel).

  Further, the devices such as the processor 1001 and the memory 1002 are connected by a bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

  The computer 100 includes hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). Alternatively, some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these hardware.

  As described above, the bridge evaluation system according to one aspect of the present disclosure includes an acquisition unit that acquires image data obtained by capturing an image of an object passing through the bridge, and a determination unit that determines the state of the bridge based on the image data. The determination unit analyzes the image data to calculate the weight of the object at each of the one or more measurement points of the bridge and the reference point of the bridge, and for each of the one or more measurement points, Is calculated as the relative weight, and the state of the bridge is determined based on the relative weight of each of the one or more measurement points.

  A bridge evaluation method according to an aspect of the present disclosure is a bridge evaluation method executed by a computer system, and includes an acquisition step of acquiring image data of an object passing through the bridge, and a state of the bridge based on the image data. A determination step for determining the weight of the object at each of the one or more measurement points of the bridge and the reference point of the bridge by analyzing the image data; For each of the measurement points, a substep of calculating the ratio of the weight at the measurement point to the weight at the reference point as a relative weight, and determining the state of the bridge based on the relative weight of each of the one or more measurement points And substeps.

  In such a side surface, the weight of the object at each measurement point of the bridge is converted into a relative value using the weight of the object at the reference point, and the state of the bridge is determined based on the relative value. With this method, it becomes possible to accurately determine the state of the bridge without accurately obtaining the load itself applied to the bridge. When using the relative weights of each of the plurality of measuring points, it is possible to determine the condition of the individual locations of the bridge and thus, for example, where the bridge is degraded.

  The relationship between the load f applied to the structure, the displacement x generated in the structure, and the rigidity k of the bridge is represented by f = kx. Therefore, originally, it is necessary to obtain the load f and the displacement x in order to obtain the rigidity k. However, as described above, it is difficult to accurately estimate the load f. In one aspect of the present disclosure, since the relative weight, which is the ratio of the object weight at the measurement point to the object weight at the reference point, is used, the rigidity k indicating the relationship or difference in rigidity between the measurement point and the reference point. It becomes possible to grasp the relative value of. Since the relative value of this stiffness k is obtained, the state of the bridge can be determined without accurately obtaining the individual loads f.

  In the bridge evaluation system according to another aspect, the image data includes first image data of the bridge in the reference period and second image data of the bridge in the inspection period, and the determination unit is based on the first image data, A relative weight distribution is generated as a first relative weight distribution for each of the one or more measurement points, and a relative weight distribution is generated as a second relative weight distribution for each of the one or more measurement points based on the second image data. However, the state of the bridge during the inspection period may be determined by comparing the first relative weight distribution and the second relative weight distribution. By comparing the relative weight distributions of the two periods, it is possible to grasp the change in the relative weight with the passage of time, so that the state of the bridge during the inspection period can be accurately determined.

  In the bridge evaluation system according to another aspect, the determination unit determines the state of the bridge during the inspection period by comparing the first average value of the first relative weight distribution and the second average value of the second relative weight distribution. You may. By comparing the average values of the two relative weight distributions, the state of the bridge can be determined easily and accurately.

  In the bridge evaluation system according to another aspect, the determination unit changes the first average value by a given amount and compares the changed first average value with the second average value, so that the inspection period You may judge the condition of the bridge. By adjusting the first average value and then comparing the two average values, it is possible to more reliably determine a significant change in the bridge in the two periods.

  In the bridge evaluation system according to another aspect, the determination unit may compare the first average value and the second average value using Welch's t-test. By using this verification method, it is possible to compare the average values of the two periods even when the sample size differs between the reference period and the inspection period, and therefore it is possible to accurately determine the state of the bridge. .

  In the bridge evaluation system according to another aspect, the image data includes first image data of the bridge at the reference time point and second image data of the bridge at the inspection time point, and the determination unit is based on the first image data, The relative weight is generated as the first relative weight for each of the one or more measurement points, and the relative weight is generated as the second relative weight for each of the one or more measurement points based on the second image data. The state of the bridge at the time of the inspection may be determined by comparing with the second relative weight. By comparing the relative weights at the two time points, it is possible to grasp the change in the relative weights with the passage of time, so that it is possible to accurately determine the state of the bridge at the time of the inspection.

  In the bridge evaluation system according to another aspect, the determination unit may select the measurement point having the largest displacement among the plurality of measurement points of the bridge as the reference point. It can be expected that the larger the displacement, the smaller the error rate. Therefore, by using the measurement point at which the maximum displacement is recorded as the reference point, it is possible to reduce the error in the relative weight and thus to accurately determine the state of the bridge.

  In the bridge evaluation system according to another aspect, the determination unit may calculate the temporary displacement by analyzing the image data, and may calculate the displacement by applying a low-pass filter to the temporary displacement. By this method, the vibration component is removed and the static change of the measurement point is obtained, so that more accurate displacement can be obtained, and thus the relative weight can be obtained more accurately.

  Although the present disclosure has been described in detail above, it is obvious to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as modified and changed modes without departing from the spirit and scope of the present disclosure defined by the description of the claims. Therefore, the description of the present disclosure is for the purpose of exemplifying description, and does not have any restrictive meaning to the present disclosure.

  The notification of information is not limited to the aspect / embodiment described in the present disclosure, and may be performed using another method. For example, the information is notified by physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, It may be implemented by notification information (MIB (Master Information Block), SIB (System Information Block)), another signal, or a combination thereof. Further, the RRC signaling may be called an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration message, or the like.

  Each aspect / embodiment described in the present disclosure is LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication). system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark) )), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), systems using other suitable systems, and extensions based on these. It may be applied to at least one of the next-generation systems. Further, a plurality of systems may be combined and applied (for example, a combination of at least one of LTE and LTE-A and 5G).

  The processing procedure, sequence, flowchart, etc. of each aspect / embodiment described in the present disclosure may be interchanged as long as there is no contradiction. For example, the methods described in this disclosure present elements of the various steps in a sample order, and are not limited to the specific order presented.

  In the present disclosure, the specific operation performed by the base station may be performed by its upper node in some cases. In a network of one or more network nodes having a base station, the various operations performed for communication with a terminal are the base station and other network nodes than the base station (eg MME or S-GW and the like are conceivable, but are not limited thereto, and it is clear that at least one of them can be used. Although the case where there is one network node other than the base station has been illustrated above, a combination of a plurality of other network nodes (for example, MME and S-GW) may be used.

  Information and the like can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

  The input / output information and the like may be stored in a specific place (for example, a memory) or may be managed using a management table. Information that is input / output can be overwritten, updated, or added. The output information and the like may be deleted. The input information and the like may be transmitted to another device.

  The determination may be performed based on a value represented by 1 bit (0 or 1), may be performed based on a Boolean value (Boolean: true or false), or may be compared by numerical values (for example, a predetermined value). (Comparison with value).

  Each aspect / embodiment described in the present disclosure may be used alone, in combination, or may be switched according to execution. Further, the notification of the predetermined information (for example, the notification of “being X”) is not limited to the explicit notification, and is performed implicitly (for example, the notification of the predetermined information is not performed). Good.

  Software, whether called software, firmware, middleware, microcode, hardware description language, or any other name, instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules. , Application, software application, software package, routine, subroutine, object, executable, thread of execution, procedure, function, etc. should be construed broadly.

  Also, software, instructions, information, etc. may be sent and received via a transmission medium. For example, the software uses a wired technology (coaxial cable, optical fiber cable, twisted pair, Digital Subscriber Line (DSL), etc.) and / or wireless technology (infrared, microwave, etc.) to use a website, When sent from a server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

  The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description include voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any of these. May be represented by a combination of

  The terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and the symbol may be a signal (signaling). The signal may also be a message. Moreover, a component carrier (CC: Component Carrier) may be called a carrier frequency, a cell, a frequency carrier, or the like.

  The terms "system" and "network" used in this disclosure are used interchangeably.

  Further, the information, parameters, etc. described in the present disclosure may be represented by using an absolute value, may be represented by using a relative value from a predetermined value, or by using other corresponding information. May be represented. For example, the radio resources may be those indicated by the index.

  The names used for the above parameters are not limiting in any way. Further, the formulas and the like that use these parameters may differ from those explicitly disclosed in this disclosure. Since different channels (eg PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the different names assigned to these different channels and information elements are in no way limited names. is not.

  In the present disclosure, "base station (BS)", "radio base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", " "Access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", " The terms "carrier", "component carrier" and the like may be used interchangeably. A base station may be referred to by terms such as macro cell, small cell, femto cell, and pico cell.

  A base station can accommodate one or more (eg, three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be partitioned into multiple smaller areas, each smaller area being defined by a base station subsystem (eg, indoor small base station (RRH: Remote Radio Head) may also be used to provide communication services.The term "cell" or "sector" refers to part or all of the coverage area of a base station and / or a base station subsystem serving communication in this coverage. Refers to.

  In the present disclosure, terms such as “mobile station (MS)”, “user terminal”, “user equipment (UE)”, and “terminal” may be used interchangeably. .

  Mobile stations are defined by those skilled in the art as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

  At least one of the base station and the mobile station may be called a transmission device, a reception device, a communication device, or the like. Note that at least one of the base station and the mobile station may be a device mounted on the mobile body, the mobile body itself, or the like. The moving body may be a vehicle (eg, car, airplane, etc.), an unmanned moving body (eg, drone, self-driving car, etc.), or a robot (manned type or unmanned type). ) May be sufficient. Note that at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

  Further, the base station in the present disclosure may be replaced by the user terminal. For example, the communication between the base station and the user terminal is replaced with the communication between a plurality of user terminals (eg, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the user terminal may have the function of the base station. In addition, the wording such as “up” and “down” may be replaced with the wording corresponding to the terminal-to-terminal communication (for example, “side”). For example, the uplink channel and the downlink channel may be replaced with the side channel.

  Similarly, the user terminal in the present disclosure may be replaced with the base station. In this case, the base station may have the function of the user terminal.

  The terms "determining" and "determining" as used in this disclosure may encompass a wide variety of actions. "Judgment", "decision" means, for example, judgment (judging), calculation (calculating), calculation (computing), processing (processing), derivation (deriving), investigating (investigating), searching (looking up, search, inquiry) (Eg, searching in a table, database, or another data structure), ascertaining to be regarded as “judgment” and “decision” may be included. In addition, "decision" and "decision" include receiving (eg, receiving information), transmitting (eg, transmitting information), input (input), output (output), access (accessing) (for example, accessing data in a memory) may be regarded as “judging” and “deciding”. In addition, "judgment" and "decision" are considered to be "judgment" and "decision" when things such as resolving, selecting, choosing, choosing, establishing, and comparing are done. May be included. That is, the “judgment” and “decision” may include considering some action as “judgment” and “decision”. In addition, “determination (decision)” may be replaced with “assuming”, “expecting”, “considering”, and the like.

  The terms "connected," "coupled," or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, It can include the presence of one or more intermediate elements between two elements that are “connected” or “coupled”. The connections or connections between the elements may be physical, logical, or a combination thereof. For example, “connection” may be read as “access”. As used in this disclosure, two elements are in the radio frequency domain, with at least one of one or more wires, cables and printed electrical connections, and as some non-limiting and non-exhaustive examples. , Can be considered to be “connected” or “coupled” to each other, such as with electromagnetic energy having wavelengths in the microwave region and the light (both visible and invisible) region.

  As used in this disclosure, the phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

  Any reference to elements using the designations "first," "second," etc. as used in this disclosure does not generally limit the amount or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, references to the first and second elements do not mean that only two elements may be employed, or that the first element must precede the second element in any way.

  Where the terms “include”, “including” and variations thereof are used in this disclosure, these terms are inclusive, as is the term “comprising”. Is intended. Furthermore, the term "or" as used in this disclosure is not intended to be an exclusive or.

  In the present disclosure, where translations add articles, such as a, an, and the in English, the disclosure may include that the noun that follows these articles is in the plural.

  In the present disclosure, the term “A and B are different” may mean “A and B are different from each other”. The term may mean that “A and B are different from C”. The terms "remove", "coupled" and the like may be construed as "different" as well.

  10 ... Bridge evaluation system, 11 ... Acquisition part, 12 ... Judgment part, 13 ... Output part, 20 ... Camera, 21 ... Image database, 22 ... Weight database, 80 ... Bridge, 80a ... Measuring point, 81-85 ... Measuring point .

Claims (9)

An acquisition unit that acquires image data of an object passing through the bridge,
A determination unit that determines the state of the bridge based on the image data,
The determination unit,
Analyzing the image data to calculate the weight of the object at each of the one or more measurement points of the bridge and the reference point of the bridge,
For each of the one or more measurement points, the ratio of the weight at the measurement point to the weight at the reference point is calculated as a relative weight,
Determining the state of the bridge based on the relative weight of each of the one or more measurement points;
Bridge evaluation system. The image data includes first image data of the bridge in a reference period and second image data of the bridge in an inspection period,
The determination unit,
Generating a distribution of the relative weight as a first relative weight distribution for each of the one or more measurement points based on the first image data;
Generating a distribution of the relative weight for each of the one or more measurement points as a second relative weight distribution based on the second image data;
Determining the state of the bridge during the inspection period by comparing the first relative weight distribution and the second relative weight distribution,
The bridge evaluation system according to claim 1. The determination unit determines a state of the bridge during the inspection period by comparing a first average value of the first relative weight distribution and a second average value of the second relative weight distribution,
The bridge evaluation system according to claim 2. The determination unit determines the state of the bridge during the inspection period by changing the first average value by a given amount and comparing the changed first average value with the second average value. To do
The bridge evaluation system according to claim 3. The determination unit compares the first average value and the second average value using Welch's t-test,
The bridge evaluation system according to claim 3 or 4. The image data includes first image data of the bridge at a reference time point and second image data of the bridge at an inspection time point,
The determination unit,
Generating the relative weight as a first relative weight for each of the one or more measurement points based on the first image data;
Generating the relative weight as a second relative weight for each of the one or more measurement points based on the second image data;
The state of the bridge at the time of the inspection is determined by comparing the first relative weight and the second relative weight,
The bridge evaluation system according to claim 1. The determination unit selects a measurement point with the largest displacement among the plurality of measurement points of the bridge as the reference point,
The bridge evaluation system according to any one of claims 1 to 6. The determination unit calculates a temporary displacement by analyzing the image data, and calculates the displacement by applying a low-pass filter to the temporary displacement,
The bridge evaluation system according to any one of claims 1 to 7. A bridge evaluation method executed by a computer system, comprising:
An acquisition step of acquiring image data of an object passing through the bridge,
And a determination step of determining the state of the bridge based on the image data,
The determination step,
A sub-step of analyzing the image data to calculate the weight of the object at each of one or more measurement points of the bridge and a reference point of the bridge;
For each of the one or more measurement points, a sub-step of calculating a ratio of the weight at the measurement point and the weight at the reference point as a relative weight,
And a sub-step of determining a state of the bridge based on the relative weight of each of the one or more measurement points.
Bridge evaluation method.

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