Derivation method, derivation apparatus, derivation system, program

Abstract

The present application relates to an extraction method, an extraction device, an extraction system, and a program, the extraction method including: an acquisition step of acquiring time-series data including a physical quantity generated at a predetermined observation point in a structure as a response caused by movement of a grouping mobile body, which is a grouping of one or more mobile bodies, on the structure; an environmental information acquisition step of acquiring, as environmental information, a structure length, a mobile body length, and information on a setting position of a contact site of the mobile body with the structure; a fundamental frequency extraction step of extracting a fundamental frequency of the time-series data based on the time-series data; a passage period extraction step of extracting a passage period of the grouping mobile body through the structure based on the time-series data; and a number extraction step of extracting a number of the mobile bodies included in the grouping mobile body based on the environmental information, the fundamental frequency, and the passage period.

Description

Technical Field

[0001] This invention relates to export methods, export devices, export systems, and programs. Background Technology

[0002] In recent years, many social infrastructures have deteriorated over time, and methods are being sought to conduct condition diagnostics on structures that constitute social infrastructure such as railway bridges.

[0003] Patent Document 1 discloses a method for investigating the structural performance of railway bridges, which can appropriately investigate and evaluate the structural performance of bridges using observational data of the bridge's acceleration response during train travel. The method in Patent Document 1 is characterized by formulating a theoretical analysis model of the dynamic response of the railway bridge during train travel, treating the train as a moving load and the bridge as a single-span beam, measuring the bridge's acceleration during train travel, and using this acceleration data to infer unknown parameters of the theoretical analysis model through reverse analysis.

[0004] In addition, Patent Document 2 discloses a method for determining the impact coefficient (dynamic response component) of a bridge by specifically using the vertical acceleration response of a train traveling across a bridge.

[0005] Patent Document 1: Japanese Patent No. 6543863

[0006] Patent Document 2: Japanese Patent No. 6467304

[0007] There are situations where convoys of multiple moving bodies, such as railway trains, move on structures like bridges. In such cases, to generate a motion model of the structure for diagnostic purposes, it is necessary to determine the number of moving bodies in the convoy moving on the structure. In Patent Document 1, the computational load of the reverse analysis method used to determine the unknown parameters is enormous. Furthermore, Patent Document 2 cannot determine the number of moving bodies in the convoy moving on the structure. Thus, Patent Documents 1 and 2 cannot determine the number of moving bodies in the convoy moving on the structure with a lower computational load. Summary of the Invention

[0008] The derivation method for solving the above problems includes: an acquisition step, acquiring time-series data of physical quantities generated at predetermined observation points in a structure, wherein the physical quantities are generated as responses caused by the movement of a group of mobile bodies with one or more mobile bodies on the structure; an environmental information acquisition step, acquiring information on the length of the structure, the length of the mobile bodies, and the location of the contact points between the mobile bodies and the structure as environmental information; a fundamental frequency derivation step, deriving the fundamental frequency of the time-series data based on the time-series data; a passage period derivation step, deriving the passage period of the group of mobile bodies through the structure based on the time-series data; and a number derivation step, deriving the number of mobile bodies included in the group of mobile bodies based on the environmental information, the fundamental frequency, and the passage period.

[0009] The derivation apparatus for solving the above-mentioned problem includes: an acquisition unit that acquires time-series data including physical quantities generated at predetermined observation points in a structure, the physical quantities being generated as responses caused by the movement of a group of mobile bodies consisting of one or more mobile bodies on the structure; an environmental information acquisition unit that acquires information as environmental information including the length of the structure, the length of the mobile bodies, and the location of contact points between the mobile bodies and the structure; a fundamental frequency derivation unit that derives the fundamental frequency of the time-series data based on the time-series data; a passage period derivation unit that derives the passage period of the group of mobile bodies through the structure based on the time-series data; and a number derivation unit that derives the number of mobile bodies included in the group of mobile bodies based on the environmental information, the fundamental frequency, and the passage period.

[0010] The derivation system for solving the above problems includes a derivation device and a sensor. The derivation device includes: an acquisition unit that acquires time-series data of physical quantities generated at predetermined observation points in a structure, the physical quantities being generated as responses caused by the movement of a group of mobile bodies containing one or more mobile bodies on the structure, the physical quantities being measured by the sensor; an environmental information acquisition unit that acquires information as environmental information, including the length of the structure, the length of the mobile bodies, and the location of contact points between the mobile bodies and the structure; a fundamental frequency derivation unit that derives the fundamental frequency of the time-series data based on the time-series data; a passage period derivation unit that derives the passage period of the group of mobile bodies through the structure based on the time-series data; and a number derivation unit that derives the number of mobile bodies included in the group of mobile bodies based on the environmental information, the fundamental frequency, and the passage period.

[0011] The program for solving the above problem causes the computer to perform the following steps: an acquisition step, acquiring time-series data of physical quantities generated at predetermined observation points in the structure, the physical quantities being generated as responses caused by the movement of a group of mobile bodies with one or more mobile bodies on the structure; an environmental information acquisition step, acquiring information as environmental information including the length of the structure, the length of the mobile bodies, and the location of the contact points between the mobile bodies and the structure; a fundamental frequency derivation step, deriving the fundamental frequency of the time-series data based on the time-series data; a passage period derivation step, deriving the passage period of the group of mobile bodies through the structure based on the time-series data; and a number derivation step, deriving the number of mobile bodies included in the group of mobile bodies based on the environmental information, the fundamental frequency, and the passage period. Attached Figure Description

[0012] Figure 1 It is a block diagram representing the structure of the exported system.

[0013] Figure 2 It is a diagram showing the cross-section of a bridge.

[0014] Figure 3 It is a diagram showing the dimensions of a unit bridge truss.

[0015] Figure 4 It is a diagram showing the dimensions of railway vehicles.

[0016] Figure 5 It is a diagram showing the outline of a unit bridge truss.

[0017] Figure 6 It is a diagram illustrating the bending moment in a unit bridge truss.

[0018] Figure 7 It is a diagram that shows the general outline of the deflection of a unit bridge truss caused by the wheels.

[0019] Figure 8 It is a diagram that shows the general deflection of a unit bridge truss caused by railway vehicles.

[0020] Figure 9 It is a diagram that shows the general deflection of a unit bridge truss caused by a railway train.

[0021] Figure 10 It is a diagram showing the deflection of a unit bridge truss caused by each railway vehicle.

[0022] Figure 11 It is a diagram showing the deflection of a unit bridge truss caused by individual railway vehicles and trains.

[0023] Figure 12 It is a graph representing the time-series data of the displacement of a unit bridge truss.

[0024] Figure 13 This is a graph representing the FFT results of time series data.

[0025] Figure 14 This is a diagram illustrating the export processing of entry and exit times.

[0026] Figure 15 This is a diagram illustrating the export processing of entry and exit times.

[0027] Figure 16 It is a graph representing the time-series data of the displacement of a unit bridge truss.

[0028] Figure 17 This is a graph representing the FFT results of time series data.

[0029] Figure 18 It is a graph representing time-series data that has undergone low-pass filtering.

[0030] Figure 19 It is a diagram that shows the details of each element of the exported system.

[0031] Figure 20 This is a flowchart representing the export process.

[0032] Explanation of reference numerals in the attached figures

[0033] 1: Measuring device; 2: Sensor device; 3: Server device; 4: Communication network; 5: Bridge; 6: Railway train; 7: Superstructure; 7a: Bridge deck; 7b: Bearing; 7c: Track; 7d: Sleeper; 7e: Ballast; F: Bridge deck; G: Main beam; 8: Substructure; 8a: Pier; 8b: Abutment; 10: Output system; 100: Control unit; 110: Storage unit; 120: Communication unit; 200: Control unit; 210: Accelerometer sensor; 220: Storage unit; 230: Communication unit; 300: Control unit; 301: Acquisition unit; 302: Environmental information acquisition unit; 303: Baseband output unit; 304: Passage period output unit; 305: Count output unit; 310: Storage unit; 320: Communication unit. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in the following order.

[0035] (1) The composition of the export system:

[0036] (1-1) Exporting the system overview:

[0037] (1-2) Flexural model:

[0038] (1-3) Verification Experiment:

[0039] Details of elements (1-4):

[0040] (2) Export processing:

[0041] (3) Other implementation methods:

[0042] (1) The composition of the export system:

[0043] (1-1) Exporting the system overview:

[0044] Figure 1 This is a block diagram illustrating an example of the configuration of the derivation system 10 according to this embodiment. The derivation system 10 is a system for deriving the number of railway vehicles included in a railway train 6 based on time-series data, wherein the time-series data includes physical quantities at predetermined observation points on a bridge 5 on which the railway train 6, consisting of one or more railway vehicles, moves. The railway train 6 is an example of a moving assembly. The railway vehicles included in the railway train 6 are examples of moving assemblies. The bridge 5 is an example of a structure on which moving assemblies move. Each railway vehicle of the railway train 6 moves on the bridge 5 via wheels mounted on its axles. The wheels are an example of the contact points between the railway vehicles and the bridge. In this embodiment, the railway vehicles that make up the railway train 6 are all structurally identical railway vehicles. Figure 1 As shown, the export system 10 includes a measuring device 1, at least one sensor device 2 installed on the superstructure 7 of the bridge 5, and a server device 3.

[0045] The measuring device 1 calculates the deflection, or displacement, of the superstructure 7 caused by the movement of the railway train 6 based on the acceleration data output from each sensor device 2. The measuring device 1 is, for example, installed on the bridge abutment 8b. The measuring device 1 and the server device 3 can communicate, for example, via a communication network 4 such as a mobile phone wireless network or the Internet. The measuring device 1 sends information about the displacement of the superstructure 7 caused by the movement of the railway train 6 to the server device 3. The server device 3 derives the number of railway cars constituting the railway train 6 based on the transmitted displacement data.

[0046] In this embodiment, bridge 5 is a railway bridge, such as a steel bridge, beam bridge, or RC bridge. RC is an abbreviation for Reinforced-Concrete. Furthermore, in this embodiment, bridge 5 is a structure suitable for BWIM (Bridge Weight In Motion). BWIM is a technique that measures the weight, number of axles, etc., of moving objects passing over a bridge by treating the bridge as a "balance scale" and measuring its deformation. Bridges whose weight can be analyzed from their deformation or torsion responses are considered suitable for BWIM. Therefore, by applying the BWIM system, which describes the physical process between the action and response of a bridge, the weight of moving objects moving on the bridge can be measured. The weight of the moving object is measured by pre-determining the correlation coefficient between displacement and load, and then using this correlation coefficient to derive the load of the moving object from the measured displacement of the bridge when the moving object passes.

[0047] Bridge 5 has a superstructure 7 that moves as a movable part and a substructure 8 that supports the superstructure 7. Figure 2 It is to make the upper structure 7 Figure 1 A cross-sectional view cut along line AA. (See diagram below.) Figure 1 and Figure 2 As shown, the superstructure 7 includes the bridge deck 7a, supports 7b, track 7c, sleepers 7d, and ballast 7e. The bridge deck 7a includes the bridge panel F, main beams G, and crossbeams (not shown). Additionally, as... Figure 1 As shown, the substructure 8 includes piers 8a and abutments 8b. The superstructure 7 is a structure that spans between adjacent abutments 8b and piers 8a, between two adjacent abutments 8b, or between two adjacent piers 8a. Hereinafter, abutments 8b and piers 8a will be collectively referred to as support portions. In this embodiment, a set of support portions and the portion of the superstructure 7 spanning between these support portions are collectively referred to as a bridge truss. That is, a single-span beam-like structure supported at both ends by two support portions is considered as a bridge truss. Therefore, Figure 1 The bridge 5 shown comprises two trusses. Hereinafter, each truss in bridge 5 will be referred to as a unit truss.

[0048] The measuring device 1 and the sensor device 2 are connected, for example, by wired or wireless means, and communicate via a communication network such as CAN (Controller Area Network).

[0049] Sensor device 2 is used to measure a predetermined physical quantity, which is used to derive the displacement (deflection) at an observation point set on the superstructure 7. In this embodiment, the predetermined physical quantity is acceleration. Furthermore, in this embodiment, sensor device 2 is disposed at the observation point. Additionally, sensor device 2 includes an acceleration sensor such as a crystal accelerometer or a MEMS (Micro Electro Mechanical Systems) accelerometer. Sensor device 2 outputs acceleration data, which is used to derive the displacement of the superstructure 7 caused by the movement of the moving body, i.e., the railway train 6, at the observation point.

[0050] In this embodiment, the sensor device 2 is disposed at the center of the superstructure 7 along its length, specifically at the center of the main beam G along its length. However, the sensor device 2 only needs to be able to detect the acceleration used to calculate the displacement of the superstructure 7, and its placement is not limited to the center of the superstructure 7. Furthermore, when the sensor device 2 is disposed on the bridge deck F of the superstructure 7, it may be damaged by the movement of the railway train 6, and the measurement accuracy may be affected by local deformation of the bridge deck 7a. Therefore, in… Figure 1 and Figure 2 In the example, sensor device 2 is installed on the main beam G of the superstructure 7.

[0051] The bridge deck F or main beam G of the superstructure 7 deflects vertically due to the load applied by the railway train 6 traveling on the superstructure 7. Each sensor device 2 measures the acceleration of the deflection of the bridge deck F or main beam G caused by the load of the railway train 6 traveling on the superstructure 7.

[0052] (1-2) Flexural model:

[0053] Here, a model of the deflection of a bridge when a railway train moves on it is explained. Here, the model consists of information such as formulas representing the correspondence between given information and derived results.

[0054] In addition, the number of railway cars (carriages) forming a railway train moving on the bridge will be denoted as N. The time when the railway train enters the bridge will be denoted as t. i Here, "train entering the bridge" refers to the entry of the first axle wheel of railway vehicle C1 (the first railway vehicle from the very front of the train) onto the bridge. Furthermore, the time when the train exits the bridge, i.e., the exit time, will be denoted as t. o Here, the train's departure from the bridge refers to railway vehicle C. N The wheels of the very last axle of the last train (the last car in the train) exit the bridge. Additionally, the following will show the time it takes for the train to cross the bridge (from time t).i up to time t o The period is set as t. s The following will discuss N and t. i t o t s This is collectively referred to as observation information.

[0055] In addition, the length of the bridge in the direction of the railway train's travel, i.e., the bridge length, will be denoted as L below. B Bridge length is an example of structural length. Furthermore, the distance from the end of the bridge along its length on the side facing the direction in which the railway trains will enter to the observation point is denoted as L. x . Figure 3 L is shown in the middle B and L X Hereinafter, the end of the bridge's length along the direction in which the railway train enters will be designated as the "entry end." Furthermore, the end of the bridge's length along the direction in which the railway train exits will be designated as the "exit end." Additionally, the length of the m-th railway car from the foremost end of the train, i.e., the car length, will be designated as L. c (m). Vehicle length is an example of the length of a moving object in the direction of its travel, i.e., the length of the moving object itself. Hereinafter, L will be discussed... c (1)~L c (N) are collectively referred to as L c Additionally, the m-th carriage from the front of the train is designated as C. m In addition, railway vehicle C m Let the number of axles in the vehicle be a. r (m). Below, a will be... r (1)~a r (N) are collectively referred to as a r The following will discuss railway vehicle C. m a in r (m) axles from railway vehicle C m Starting from the very beginning, let's call them the first axis, the second axis, the third axis, ..., the ath axis. r (m) axis.

[0056] In addition, railway vehicle C m Let L be the distance from the end of the direction of travel in front of the first axis. a (a w (m,1)). Here, a w (α,β) represents the β-th axle starting from the foremost axle of the α-th car in a railway train. Additionally, the railway car C... m Let L be the distance between the (n-1)th axis (where n is an integer greater than 2) and the nth axis. a (a w (m,n)). That is, for β greater than 2, La (a w (α,β) represents the railway vehicle C. α The distance between the β-th axis and the (β-1)-th axis in L. Additionally, L a (a w (α,1) represents the railway vehicle C. α The first axle in the middle and railway vehicle C α The distance between the ends of the vehicle in the direction of travel. Hereinafter, L will be... a (a w (1,1))~L a (a w (N,a r (N))) collectively referred to as L a L a These represent the positions of the corresponding axles in the corresponding railway vehicles. For example, L a (a w (m,1) represents the railway vehicle C m In the middle, at a distance L from the front end a (a w There exists a first axis behind (m,1)). Additionally, L a (a w (m,2) represents the railway vehicle C m In the middle, at a distance L from the first axis a (a w There exists a second axis behind (m,2)).

[0057] Here, railway trains consist of railway vehicles with the same four-axle structure. That is, a r (m)(m=1、2、……、N) is 4. Figure 4 Railway vehicle C is shown in the middle. m L in c (m), L a (a w (m,1)), L a (a w (m,2)), L a (a w (m,3)), L a (a w (m,4)).

[0058] The following will be L B L x L c a r L a Collectively referred to as environmental information.

[0059] As shown in equation (1) below, t s As t o With ti It is obtained by the difference.

[0060] t s =t0-t i ···(1)

[0061] In addition, the total number of wheels of the railway train T ar It can be obtained by the following equation (2).

[0062]

[0063] From the first axle of the leading railway car C1 to the mth railway car C... m The distance up to the nth axis is denoted as D. wa (a w (m,n)). D wa (a w (m,n) can be obtained from the following equation (3).

[0064]

[0065] From the first axle of the foremost railway car C1 to the last railway car C N The last axis a r The distance up to (N) is D. wa (a w (N,a r (N))). Using D wa (a w (N,a r (N))), the average speed v of the railway train crossing the bridge a It is expressed as equation (4) below.

[0066]

[0067] From equations (3) and (4), we can see that equation (5) holds true.

[0068]

[0069] Next, the deflection of the bridge when a load is applied to it will be explained.

[0070] Figure 5 A schematic diagram showing a bridge. Figure 5 The diagram illustrates a situation where a load P is applied to a bridge. Here, the distance between the location where the load P is applied and the entry end of the bridge is denoted as a. Additionally, the distance between the location where the load P is applied and the exit end of the bridge is denoted as b. In this case, the bending moment at the location where the load P is applied in the bridge is represented by the following equation (6).

[0071]

[0072] Figure 6 This represents the bending moment at various locations on the bridge caused by the load P. For example... Figure 6 As shown, since the bending moment generated by load P on the bridge is 0 at the entry end, it increases proportionally from the entry end towards the position where load P is applied, becoming the value shown in equation (6) at the position where load P is applied. Furthermore, since the bending moment generated by load P on the bridge decreases proportionally from the position where load P is applied towards the exit end, it becomes 0 at the exit end. Therefore, the bending moment at any position X in the bridge is represented by the following equation (7).

[0073]

[0074] In equation (7), x represents the distance from the entry point to position X in the direction of travel of the railway train.

[0075] In addition, Ha in equation (7) is the value shown in equation (8) below.

[0076]

[0077] The following equation (9) holds true between the deflection w and bending moment of a bridge at any location X.

[0078]

[0079] In equation (9), θ is the angle formed by the horizontal line at position X and the deflected bridge. From equations (7) and (9), it can be seen that the following equation (10) holds true.

[0080]

[0081] By integrating x twice over both sides of equation (10), we can obtain the following equation (11) which represents the deflection w at position X.

[0082]

[0083] In equation (11), g1 and g2 are constant terms. Here, since the bridge is supported at the entry and exit ends, no deflection occurs at these positions. That is, in equation (11), when x = 0 and x = L... B When both sides are 0, g1 and g2 become equations (12) and (13) respectively.

[0084] g1=ab(a+2b)··· (12)

[0085] g2=0···(13)

[0086] Based on equations (11), (12), and (13), the following equation (14) is derived to represent the deflection w at position X.

[0087]

[0088] When a load P is applied to the center of the bridge along its length, the maximum deflection caused by the applied load P occurs at the center of the bridge's length. Let this maximum deflection be w. 0.5l And find the representation of w. 0.5l The formula is: When a load P is applied to the center of the bridge along its length, a = b = 0.5L. B Furthermore, since the determined location X of the deflected object is the center of the bridge's length, x = 0.5L. B Furthermore, in this case, since x≤a, it becomes H according to equation (8). a =0. By x = 0.5L B a = b = 0.5L B H a Substituting 0 into equation (14), we can find the value representing the deflection w. 0.5l The following formula (15).

[0089]

[0090] Use w 0.5l Normalize the deflection at any position in the bridge represented by equation (14).

[0091] When the position of load P is closer to the entry end than position X, i.e., x > a, it becomes Ha = 1 according to equation (8), and equation (14) is expressed as in equation (16) below.

[0092]

[0093] Let a = L B r. Here, r is a real number greater than 0 and less than 1. Since b = L B -a, therefore it can be expressed as b=L B (1-r). If a = L B r, b = L B Substitute (1-r) into equation (16) and divide by w 0.5l After normalization, the following equation (17) is obtained, which represents the normalized deflection w at position X when x > a. std .

[0094]

[0095] Similarly, when the load P is located closer to the exit end than the location X, i.e., x ≤ a, it becomes H according to equation (8). a =0, and equation (14) is expressed as in equation (18) below.

[0096]

[0097] Let a = L B r. Here, r is a real number greater than 0 and less than 1. Since b = L B -a, therefore it can be expressed as b=L B (1-r). If a = L B r, b = L B Substitute (1-r) into equation (18) and divide by w 0.5l After normalization, the following equation (19) is obtained, which represents the normalized deflection w at position X when x≤a. std .

[0098]

[0099] By L x Substituting x into equations (17) and (19), the normalized deflection w at the observation point of the deflection. std As a function of r, it is expressed as in equation (20) below.

[0100]

[0101] The function R(r) in equation (20) is the function shown in equation (21) below.

[0102]

[0103] Here, using equations (20) and (21), we obtain the expression representing the effect of passing through any axle a. w The time variation of the deflection at the observation point caused by the load applied to the bridge by the (m,n) wheels is a function of this time variation. First, let t be the time it takes for a wheel of one axle of a railway train to travel from the entry point to the observation point. xn . t xn From L using the following equation (22) x and v a Find the answer.

[0104]

[0105] Additionally, let t be the time it takes for one wheel of a railway train to cross the bridge, i.e., the time it takes to travel from the entry end to the exit end. ln . t ln From L using the following equation (23) Band v a Find the answer.

[0106]

[0107] In addition, the nth axle of the mth railway car of the railway train w Let t be the time when the wheel of (m,n) arrives at the entry end. o (m,n). t o (m,n) is obtained from t through the following equation (24). i v a and D wa (a w Find (m,n)).

[0108]

[0109] According to equation (22), L x As shown in equation (25) below.

[0110] L x =v a t xn ···(25)

[0111] In addition, according to equation (23), L B As shown in equation (26) below.

[0112] L B =v a t ln ···(26)

[0113] axle w The position (m,n) becomes the load position. Therefore, axle a w The position (m,n) is a distance of a = L from the entry end towards the exit end. B The position of r. Additionally, if the variable representing time is t, then a at time t... w (m,n) distance from the entry point and from time t o The distance traveled by the railway vehicles from (m,n) up to time t is equal. Therefore, the following equation (27) holds.

[0114] L B r = v a (t-t0(m,n))···(27)

[0115] According to equation (27), r is expressed as in equation (28) below.

[0116]

[0117] By replacing L in equations (20) and (21) with equations (25), (26), and (28). x L B Given r, find the function w of the following equation (29). std (a w (m,n),t), as a representation of the effect of passing through axle a w The model represents the time variation of the deflection at the observation point caused by the load applied to the bridge by the wheel (m,n). The function R(t) in equation (29) is the function shown in equation (30) below.

[0118]

[0119]

[0120] When the observation information and environmental information (t) i t o N, L B L x L c (1)~L c (N), a r (1)~a r (N), L a (a w (1,1))~L a (a w (N,a r When (N) is known, use this information to calculate w. std (a w (m,n),t). For example, using equation (1) from t i t o Find t s Using equation (5) from t s N, a r L a L c Find v a Using equations (22) and (23) from v a L B and L x Find t xn t ln Using equations (3) and (24) from L a L c t i Find t o (m,n). Furthermore, by obtaining t... xn t ln t o Substituting (m,n) into equations (29) and (30), we can find the function w of t. std (aw (m,n),t).

[0121] w std (a w An example of the change in deflection at the observation point (m,n),t is shown in Figure 7 . Figure 7 The horizontal axis of the chart represents time, and the vertical axis represents deflection. Additionally, this corresponds to a single railway car C. m The movement, a r (m) groups of wheels, each belonging to an axle, move on the bridge. Therefore, the function C std (m,t) represents w for each axle. std (a w The sum of (m,n),t) is obtained as shown in equation (31) below, and the function C std (m,t) represents the passage of a railway car C. m A model of the time-varying amount of deflection at the observation point caused by the movement of the object.

[0122]

[0123] when a r When (m) is 4, that is, railway vehicle C m When it is a four-axis structure, the function C std The variation of deflection at the observation point (m,t) is shown in the figure. Figure 8 . Figure 8 The horizontal axis of the chart represents time, and the vertical axis represents deflection. Additionally, Figure 8 The solid line in the chart represents C. std (m,t), the dashed lines in the graph represent w for each axle. std (a w (m,n),t).

[0124] Additionally, corresponding to the movement of the railway train, N railway cars move on the bridge. Therefore, the function T std (t) as C regarding each railway vehicle std The sum of (m,t) is obtained as shown in equation (32) below, and the function T std (t) serves as a model representing the time variation of the deflection at the observation point caused by the movement of a railway train.

[0125]

[0126] When N is 16, that is, when the railway train consists of 16 railway cars, the function T will... std The change in deflection at the observation point shown in (t) is illustrated in... Figure 9 . Figure 9The horizontal axis of the chart represents time, and the vertical axis represents deflection. Additionally, Figure 9 The solid line in the chart represents T. std (t), the dashed lines in the graph represent C for each railway vehicle. std (m,t). For example... Figure 9 The graph shows the waveform after adding the deflections of each passing railway vehicle, which indicates that a periodic vibration is generated as vehicles pass over the bridge continuously.

[0127] The above is an explanation of the flexural model in bridges.

[0128] (1-3) Verification Experiment:

[0129] Given the observation and environmental information values ​​shown below, the deflection C generated when a railway train with identical rolling stock crosses a bridge is... std (1,t)~C std (N,t), T std (t) is considered. That is, N = 4, t i =7.21 [seconds], t o = 8.777 [seconds], t s = 1.567 [seconds], L B =25[m], L x =12.5 [m], each L c =25[m], each a r =4. For each m = 1 to N, L a (a w (m,1))=2.5[m],For each m=1~N, L a (a w (m,2))=2.5[m],For each m=1~N, L a (a w (m,3))=15[m],For each m=1~N, L a (a w (m,4))=2.5[m].

[0130] The deflection C of each of the four railway cars in the train at this time std (1,t)~C std (4,t) is shown in Figure 10 Let T be the period of vibration generated by the bridge when railway vehicles continuously pass over it. f The vibration generated on a bridge when railway vehicles continuously pass over it is the vibration caused by the continuous passage of railway vehicles. Therefore, the period T fThis becomes the time difference between the entry times of consecutive railway vehicles crossing the bridge. From the moment a railway vehicle enters the bridge, the bridge begins to deflect due to that vehicle; therefore, C... std The starting time of the deflection shown in (m,t) is related to C. std The time difference between the start times of the deflection shown in (m+1,t) is called the period T. f . Figure 10 This illustrates the deflection of a bridge caused by the individual passing of railway vehicles as a train crosses it. Figure 10 The horizontal axis of the chart represents time, and the vertical axis represents deflection. For example... Figure 10 As shown, the deflection caused by the preceding and following railway vehicles is expressed as T. f The time difference is generated.

[0131] Due to period T f It is the time difference between the entry times of continuous railway vehicles entering the bridge via the bridge. Therefore, as shown in the following equation (33), it can be regarded as the speed v a By vehicle length L c (m) period.

[0132]

[0133] Railway cars C of railway trains m Let the time spent crossing the bridge be t. c (m). t c (m) is the railway vehicle C, which is a moving part. m An example of the period during which a moving body passes through a bridge that serves as a structure. c (m) is from railway vehicle C m The moment the first axle arrives at the entry end of the railway vehicle C m The a r (m) The period up to the moment the axis reaches the exit end. That is, t c (m) is the railway vehicle C m The moving bridge is L long B With railway vehicle C m The foremost axle (i.e., the first axle) to the last axle (i.e., the athlephant a) r The total distance of the (m) axis over a period of time. Therefore, t c (m) is represented by the following equation (34).

[0134]

[0135] When a railway train crosses a bridge, the number of railway cars in the train that have subsequent railway cars is denoted as C. TnIn a railway train, all rolling stock except the last one may have subsequent rolling stock. Therefore, C Tn Let N be a number that is 1 less than N. That is, the following equation (35) holds.

[0136] t s =C Tn T f +t c (m)···(,3,5)

[0137] Figure 11 C is shown std (1,t)~C std (N,t), T std (t). Figure 11 The horizontal axis of the chart represents time, and the vertical axis represents the amount of deflection. Figure 11 The solid line in the chart represents T. std (t), the dashed lines in the graph represent C respectively. std (1,t)~C std (4,t). For example... Figure 11 As shown, during period t s It is C Tn T f With a railway car C m The time t during the crossing of the bridge c The sum of (m). That is, the following equation (36) holds.

[0138] N = C Tn +1···(36)

[0139] According to equations (35) and (36), the number N of railway vehicles that make up a railway train is represented by the following equation (37).

[0140]

[0141] T f It is also the time it takes for a railway train to move the length of one railway car. Therefore, the time t takes for the railway train to pass through is... s The distance traveled is the length of (N-1) railway cars and the distance traveled at a speed of v. a Forward t c The sum of the distances over a period of (m). Therefore, the following equation (38) holds.

[0142]

[0143] From equation (38), we can see that equation (39) holds true. From equation (39), we can also confirm that equation (37) holds true.

[0144]

[0145] The deflection T of a bridge when a railway train passes over it is considered to be... std In (t), the fundamental frequency component includes the vibration component generated on the bridge due to the continuous movement of railway vehicles. Here, the fundamental frequency refers to the frequency of the lowest frequency component included in the signal. Let this fundamental frequency be F. f F f It also corresponds to the frequency of vibration generated on the bridge due to the continuous movement of railway vehicles, and therefore, as shown in the following equation (40), it can be expressed as t f The reciprocal of.

[0146]

[0147] According to equations (33) and (40), the velocity v a As shown in equation (41) below, F f With L c The product of (m) is represented.

[0148] v a =F f L c (m)···(41)

[0149] Therefore, t as represented by equation (34) c (m) is the bridge length L B With railway vehicle C m The foremost axle (i.e., the first axle) to the last axle (i.e., the athlephant a) r The total distance of the (m) axis divided by F f With L c The value is obtained by producting (m).

[0150] According to equations (37) and (40), the number N of railway vehicles in a train is represented by the passage time t during which the train crosses the bridge. s Subtract one railway car C m The passage time t of the bridge c The value of (m) and the fundamental frequency F f The value obtained by adding 1 to the product is expressed as shown in the following formula (42).

[0151] N=(t s -t c (m)F f +1···(42)

[0152] The inventors discovered that, as shown in equation (41), the average speed v of the railway train a From the base frequency F f A railway car C included in a railway train mThe product of lengths is represented by the product of lengths. Furthermore, the inventors discovered that, as shown in equation (34), a railway vehicle C... m The time t during the crossing of the bridge c (m) represents railway vehicle C m With speed v a The length L of the moving bridge B With railway vehicle C m The first axis to the a r (m) The total distance of the axis during the period. Furthermore, the inventors discovered that, as shown in equation (42), the number N of railway vehicles forming a railway train is expressed as from t s Subtract t c The value of (m) and the fundamental frequency F f The value is obtained by adding 1 to the product.

[0153] Furthermore, the inventors devised a method to derive the number of railway vehicles that make up a railway train by using time-series data of displacement at observation points set at bridges where railway trains are moving.

[0154] The inventors came up with the following method.

[0155] Time-series data of displacement at observation points on a bridge subject to railway train movement are acquired. Hereinafter, the time-series data of displacement at the observation points on the bridge is denoted as u(t). u(t) represents the discrete values ​​of displacement measured at a predetermined period, and each discrete value corresponds to a measurement time. Additionally, L is acquired... B L c and L a This serves as environmental information. Furthermore, based on the time-series data u(t), the fundamental frequency F of u(t) is obtained. f The frequency of vibrations generated on the bridge due to the continuous passage of railway vehicles forming a train. Furthermore, the duration t of the train crossing the bridge is derived based on u(t). s Moreover, based on L B L c L a F f and t s The number of railway vehicles included in a railway train is derived using the relationships shown in equations (34), (41), and (42).

[0156] The inventors conducted experiments to verify the effectiveness of the proposed method. The experiment is described below.

[0157] The inventors obtained time-series data on the displacement at the observation point by periodically measuring the displacement of a railway train consisting of 16 railway cars passing over a predetermined bridge at a set observation point. This predetermined bridge is designated as the first bridge. In the first bridge, the passage of the railway train does not induce vibration resonance, unlike the vibration caused by the continuous passage of a railway train consisting of multiple train cars. Here, resonance refers to the vibration generated in the bridge due to the passage of the railway train being approximately the same as the bridge's natural frequency, thereby exciting vibrations in the bridge at the natural frequency or higher harmonics of the natural frequency. The vibration caused by resonance will be defined as the dynamic response.

[0158] The environmental information at this point is known, as described below. L B =25[m], L x =12.5 [m], each L c =25[m], each a r =4. For each m = 1 to N, L a (a w (m,1))=2.5[m],For each m=1~N, L a (a w (m,2))=2.5[m],For each m=1~N, L a (a w (m,3))=15[m],For each m=1~N, L a (a w (m,4))=2.5[m].

[0159] Furthermore, regarding observational information, everything except N is unknown. That is, t i t o t s The number of railway cars N in the train is 16.

[0160] Figure 12 The time-series data u(t) of the displacement of the observation point in the first bridge obtained by the inventors are shown. Figure 12 The horizontal axis of the chart represents time, and the vertical axis represents the amount of deflection.

[0161] The inventors performed a Fast Fourier Transform (FFT) on u(t). The results of the FFT on u(t) are shown below. Figure 13 . Figure 13 The horizontal axis of the graph represents frequency, and the vertical axis represents the intensity of the component corresponding to that frequency. Furthermore, the inventors derived the fundamental frequency F of u(t) from the FFT results of u(t). fThe frequency of the vibration generated on the first bridge based on the continuous movement of railway vehicles is denoted as . Specifically, the inventors removed the side lobes caused by the window function used in the FFT from the FFT result of u(t), determined the peak value corresponding to the lowest frequency, and calculated the determined peak value as the fundamental frequency. Figure 13 In the example, the inventors from Figure 13 The chart determined 3.01Hz as the fundamental frequency F. f .

[0162] In addition, the inventors calculated the already determined fundamental frequency F. f The reciprocal of the equation was used to calculate the period T of the vibration caused by the passing of a railway train on the first bridge. f The inventors used a period T f A moving average is applied to u(t), thus performing a low-pass filter on u(t) to attenuate frequency components above the fundamental frequency. Let u(t) after the low-pass filtering be denoted as u0. lp (t)=u lp (kΔT). Here, k is a variable representing the nth observation when the deflection is observed periodically at the observation point. That is, if the data period (time resolution) of the deflection observation is ΔT, then t = kΔT. The details of the low-pass filtering process are explained below.

[0163] As shown in equation (43) below, from period T f Calculate the time-resolution moving average interval k of the data using ΔT. mf .

[0164]

[0165] Use k mf u is obtained through the following equation (44). lp (t).

[0166]

[0167] The inventors used formula (43) from the period T f k was obtained from ΔT. mf And use equation (44) to obtain k mf u was obtained from u(t) lp (t). The above is a detailed explanation of low-pass filtering. This low-pass filtering process can also be achieved by applying a filter that makes the fundamental frequency F... f The above-mentioned component attenuation conditions are processed by FIR filtering.

[0168] Moreover, the inventors from u lp (t) determines a predetermined threshold C related to the deflection. LTwo consecutive data points. Here, u is referred to as... lp Two consecutive data points of (t) sandwiched by C L , indicating C L Included in by u lp The threshold C is the range between the values ​​of two consecutively measured displacements included in (t), that is, the range above the value of the smaller displacement and below the value of the larger displacement. L This is the value of deflection on the bridge caused by a railway train entering the bridge, for example, the deflection value at an observation point when the railway vehicle is configured such that the wheels of the first axle at the very front of the train are placed near the entry end. Additionally, this threshold C... L The threshold C can be any value, as long as it can detect the entry of a railway train onto the bridge. For example, it could be the deflection at an observation point on the bridge when a predetermined weight is applied near the entry point. L It can also be a predetermined proportion (e.g., 10%, 1%, etc.) of the maximum deflection at the observation point of the bridge when a railway train passes over it. Additionally, the threshold C... L It can also be set to u lp The value of any data included in (t).

[0169] Figure 14 Show u lp (t) and threshold C L . Figure 14 The horizontal axis of the graph represents time (t = kΔT), and the vertical axis represents the deflection. Figure 14 The solid line in the chart represents u lp (t), the dashed line in the graph represents u(t). Figure 14 In the part enclosed by the dashed circle, u lp (t) and threshold C L Intersection. Additionally... Figure 15 Show u lp (t) and C L The intersection ( Figure 14 An enlarged view of the dotted circle on the left side of the chart. Figure 15 The horizontal axis of the chart represents time, and the vertical axis represents the amount of deflection. Figure 15 The black dots represent u respectively lp The discrete values ​​included in (t). Figure 15 In the example, u is shown lp The data k-1 and k included in (t) are sandwiched by the threshold C. L The state.

[0170] The inventors determined the clamping C that was determined. L The later of two consecutive data points corresponds to the later of the two time points. Figure 15In the example, the time kΔT corresponding to the data k is determined.

[0171] exist Figure 14 In the examples, the inventors also determined Figure 14 The two data points in the dashed circle on the right side of the middle section serve as the sandwich for C. L Two consecutive data points are obtained, and the later of the two times corresponding to the two determined data points is identified.

[0172] Furthermore, the inventors used the earlier of the determined times as the entry time t for the railway train to enter the bridge. i Derivation. Furthermore, the inventors used the later of the determined times as the exit time t for the railway train leaving the bridge. o Export. Figure 14 In the example, the inventors derived the entry time t i =7.2[s], Exit time t o =12.795[s]. Furthermore, the inventors derived t s For t o -t i =12.795-7.2=5.595 [seconds].

[0173] The inventors based on L c (m) = 25[m] and the calculated F f = 3.01 [Hz], and the average speed v of the railway train was derived using equation (41). a It is 25 [m] × 3.01 [Hz] = 75.25 [m / s]. Furthermore, the inventors based their work on L... B L a And the exported v a And using equation (34), a section of railway vehicle C was derived. m The period t during the crossing of the first bridge c (m) is (25+2.5+2.5+15+2.5-2.5) / 75.25=0.5980 [seconds]. Furthermore, the inventors, based on the derived F... f t s and t c (m), and using equation (42), the number of railway cars N in a railway train was derived as (5.595-0.5980)×3.01+1=16.04097. This estimated value is approximately the number of railway cars N, which is 16. Therefore, the inventors confirmed that the number of railway cars included in a railway train can be derived with high accuracy using the conceived method.

[0174] Furthermore, the inventors conducted the following experiment: Using a devised method, they derived the number of railway vehicles forming the train when the same train passed over a second bridge, different from the first bridge. On the second bridge, the passing of the train resonated with the vibrations generated on the bridge due to the passage of the train composed of consecutive railway vehicles.

[0175] The environmental information at this point is known, as described below. L B =25[m], L x =12.5 [m], each L c =25[m], each a r =4. For each m = 1 to N, L a (a w (m,1))=2.5[m],For each m=1~N, L a (a w (m,2))=2.5[m],For each m=1~N, L a (a w (m,3))=15[m],For each m=1~N, L a (a w (m,4))=2.5[m].

[0176] Furthermore, regarding observational information, everything except N is unknown. That is, t i t o t s The number of railway cars N in a train is 16.

[0177] The inventors obtained time-series data of the displacement at observation points on the second bridge by periodically measuring the bridge displacement at predetermined periods ΔT as a railway train passes over the second bridge. The time-series data of the displacement at the observation points on the second bridge obtained by the inventors is denoted as u(t). Figure 16 The value of u(t) is shown. Figure 16 The horizontal axis of the chart represents time, and the vertical axis represents deflection. Figure 16 In the chart, with Figure 12 Compared to the chart, this shows the dynamic response generated in the bridge.

[0178] The inventors performed an FFT on u(t). The results of the FFT on u(t) are shown below. Figure 17 . Figure 17The horizontal axis of the graph represents frequency, and the vertical axis represents the intensity of the components corresponding to those frequencies. Furthermore, the dynamic response is generated through resonance with the vibrations produced on the second bridge due to the passage of a railway train. Therefore, the components of the dynamic response consist of components at frequencies approximately the same as the frequency of the vibrations produced on the second bridge due to the passage of a railway train, as well as components at frequencies that are integer multiples of that frequency. Thus, the inventors have discovered that even when the influence of the dynamic response is included in u(t), the fundamental frequency of u(t) represents the frequency of the vibrations produced on the second bridge due to the passage of a railway train.

[0179] Therefore, the inventors derived the fundamental frequency F of u(t) from the FFT of u(t). f The frequency of vibrations generated on the second bridge due to the continuous movement of railway vehicles. Figure 17 In the example, the inventors from Figure 17 The chart determined 2.8Hz as the base frequency F. f .

[0180] In addition, the inventors calculated the already determined fundamental frequency F. f The reciprocal of the equation was used to calculate the period T of the vibration caused by the passing of a railway train on the second bridge. f The inventors calculated u(t) by performing a moving average on u(t) and applying a low-pass filter to attenuate frequency components above the fundamental frequency. lp (t). Specifically, the inventors used equation (43) from period T f k was obtained from ΔT. mf And use equation (44) to obtain k mf u was obtained from u(t) lp (t). Therefore, the influence of the dynamic response in u(t) is reduced. Figure 18 In the middle, u lp (t) and u(t) are represented by overlapping. Figure 18 The horizontal axis of the chart represents time, and the vertical axis represents the amount of deflection. Figure 18 The solid line in the chart represents u lp (t), the dashed line in the graph represents u(t). Figure 18 This illustrates the scenario where the impact of the dynamic response is reduced.

[0181] Moreover, the inventors from u lp (t) determined two sets of predetermined thresholds C related to the deflection. L Two consecutive data points. The inventors determined the values ​​corresponding to the determined C for each of the two determined sets. L The inventors derived the earlier of the two determined timestamps from the two consecutive data points, using it as the entry time t. iThe later side was derived as the exit time t. o The inventors derived t i It is 5.984 seconds, t o It is 12.284 [seconds]. The inventors derived t s For t o -t i =12.284 - 5.984 = 6.3 [seconds]. This is achieved by using a u that has undergone low-pass filtering. lp The influence of dynamic response is reduced, thus allowing the entry time t to be derived with higher accuracy. i and exit time t o .

[0182] The inventors based on L c (m) = 25[m] and the calculated F f = 2.8 [Hz], and the average speed v of the railway train was derived using equation (41). a It is 25 [m] × 2.8 [Hz] = 70 [m / s]. Furthermore, the inventors based their work on L... B =46.77[m], L a And the exported v a And using equation (34), a section of railway vehicle C was derived. m The time t during the crossing of the bridge c (m) is (46.77+2.5+2.5+15+2.5-2.5) / 70 = 0.954 [seconds]. Furthermore, the inventors, based on the derived F... f t s and t c (m), and using equation (42), the number of railway cars N in a trainset is derived as (6.3-0.954)×2.8+1=15.9692. This estimated value is approximately the number of railway cars N, which is 16. Therefore, the inventors have confirmed that the number of railway cars included in a train can be derived with high accuracy using the conceived method.

[0183] The derivation system 10 of this embodiment is based on the method conceived by the inventors and on the time-series data of the displacement at the observation point in the unit truss of the bridge 5 to derive the number of railway vehicles that make up the railway train 6.

[0184] Details of elements (1-4):

[0185] Here, use Figure 19 The details of the measuring device 1, sensor device 2, and server device 3 of the export system 10 are described.

[0186] In this embodiment, the deriving system 10 derives observation information (the number N of railway cars forming the railway train 6, the time t when the railway train 6 enters the unit bridge truss) based on the data measured by the measuring device 1. i The time t when the railway train exits the unit bridge truss. o The time t during which a railway train 6 passes through the unit bridge truss s ).

[0187] The measuring device 1 measures the deflection at the observation point via the sensor device 2. In this embodiment, the measuring device 1 is installed on the bridge abutment 8b, but it can also be installed in other locations. The measuring device 1 includes a control unit 100, a storage unit 110, and a communication unit 120. The control unit 100 includes a processor such as a CPU (Central Processing Unit), ROM (Read-Only Memory), RAM (Random Access Memory), etc. The control unit 100 implements the various functions of the measuring device 1 by loading various programs recorded in the ROM, etc., into the RAM and executing them via the CPU. The storage unit 110 stores various programs, measured deflection data, etc. The communication unit 120 includes circuitry for wired or wireless communication with external devices.

[0188] Sensor device 2 detects acceleration as a predetermined physical quantity at an observation point. Sensor device 2 includes a control unit 200, an acceleration sensor 210, a storage unit 220, and a communication unit 230. The control unit 200 includes a processor such as a CPU, ROM, RAM, etc. The control unit 200 implements the various functions of sensor device 2 by loading various programs recorded in the ROM, etc., into RAM and executing them via the CPU.

[0189] Accelerometer 210 is an accelerometer such as a crystal accelerometer or a MEMS accelerometer capable of detecting acceleration generated in each of the three mutually orthogonal axes. In this embodiment, accelerometer 210 is configured such that one axis is parallel to the vertical direction to detect vertical acceleration with higher accuracy. However, there are also cases where the sensor device 2 in the upper structure 7 is tilted. Even if one of the three detection axes of accelerometer 210 is not aligned with the vertical direction, the measuring device 1 will still synthesize the accelerations of the three axes to detect vertical acceleration.

[0190] The control unit 200 of the sensor device 2 periodically detects the vertical acceleration at an observation point in the bridge 5 via the accelerometer 210 and sends the detected acceleration data to the measuring device 1. The control unit 100 of the measuring device 1 measures the vertical deflection of the bridge 5 at the observation point at the moment of acceleration detection based on the acceleration data sent from the sensor device 2. In this embodiment, the control unit 100 performs a double integration over time of the acceleration represented by the data sent from the sensor device 2 to calculate the vertical deflection of the bridge 5 at the observation point. Furthermore, the control unit 100 sends the measured deflection data to the server device 3. In this embodiment, the sensor device 2 detects acceleration at a predetermined period ΔT. Therefore, the measuring device 1 measures the time-series data of the deflection over the period ΔT. That is, the measured time-series data is data of discrete values ​​varying over the period ΔT, and each discrete value corresponds to a measurement time.

[0191] Server device 3 derives the number of railway vehicles included in railway train 6 based on the deflection of observation points measured by measuring device 1. Server device 3 is an example of a derivation device. Server device 3 includes a control unit 300, a storage unit 310, and a communication unit 320. Control unit 300 includes a processor such as CPU, ROM, RAM, etc. Control unit 300 loads various programs recorded in ROM, etc., into RAM and executes them via CPU, thereby realizing the functions of acquisition unit 301, environmental information acquisition unit 302, baseband derivation unit 303, transit time derivation unit 304, and number derivation unit 305. Storage unit 310 stores various programs, detected deflection data, etc. Communication unit 320 includes circuitry for wired or wireless communication with external devices.

[0192] The function of the acquisition unit 301 is to acquire the timing data of the deflection generated at the observation point as a response to the movement of the railway train 6 on each bridge in the bridge 5. The control unit 300 acquires the timing data u(t) of the deflection generated at the observation point from the measuring device 1 through the function of the acquisition unit 301.

[0193] The function of the environmental information acquisition unit 302 is to acquire environmental information, including the bridge length of the unit bridge truss, the length of the railway vehicles of the railway train 6, and the wheel positions (axle positions) of the railway vehicles. The control unit 300 acquires the bridge length L of the unit bridge truss through the function of the environmental information acquisition unit 302. B The length L of each railway car in railway train 6 c , representing the distance L between the positions of each railway car of railway train 6. aThe information is used as environmental information. In this embodiment, environmental information is stored in advance in the storage unit 310, and the control unit 300 obtains the environmental information from the storage unit 310. However, the control unit 300 may also obtain environmental information using other methods, such as receiving environmental information from an external device.

[0194] The function of the fundamental frequency derivation unit 303 is to derive the fundamental frequency F of u(t) based on the time-series data u(t). f The fundamental frequency F of u(t) f This represents the frequency of vibration generated in the unit bridge truss due to the passage of the railway train 6. The control unit 300 performs an FFT on u(t) using the function of the fundamental frequency derivation unit 303. The control unit 300 detects peak values ​​from the FFT results. The control unit 300 determines the lowest frequency among the detected peak values, excluding the peak values ​​of sidelobes caused by the window function used in the FFT. The control unit 300 derives the frequency corresponding to the determined peak value as the fundamental frequency F of u(t). f .

[0195] The function of the time-derivation section 304 is to derive the passage time t of the railway train 6 through the unit bridge truss based on the time-series data u(t). s The control unit 300, through the function of the period export unit 304, exports the baseband F obtained through the function of the baseband export unit 303. f The reciprocal of is used to derive the period T of the vibration generated in the unit bridge truss due to the passage of a railway train 6. f The control unit 300 derives the interval k based on the derived Tf and ΔT as a given period, and uses equation (43) to derive the interval k. mf The control unit 300 takes the derived interval k for each value of u(t). mf The moving average in the equation is used to apply a low-pass filter to u(t), resulting in u(t) that has undergone low-pass filtering, i.e., u0. lp (t). Specifically, the control unit 300 is based on the derived interval k. mf And derive u using equation (44) lp (t).

[0196] Moreover, the control unit 300 from u lp (t) Determine a given threshold C related to the deflection. L Two consecutive data points. Control unit 300 determines the value sandwiched between C. L The later of two consecutive data points corresponds to the later of the two time points.

[0197] Furthermore, the earlier of the determined times derived by the control unit 300 is taken as the entry time t of railway train 6 entering the unit bridge truss. iAdditionally, the later of the determined time derived by the control unit 300 is used as the exit time t of the railway train 6 exiting the bridge truss unit. o .

[0198] Thus, in this embodiment, the control unit 300 outputs u lp (t) includes, and is sandwiched with C L The later of the two consecutive data points is taken as the entry time t. i Exit time t o However, the control unit 300 can also derive other times as the entry time t. i Exit time t o For example, the control unit 300 can also be controlled from u lp (t) Determine a given threshold C related to the deflection. L Given two consecutive data points, the time interval between one of the determined data points and the other corresponding to that time point is taken as the entry time t. i and exit time t o .exist Figure 15 In the example, the control unit 300 can also derive the time after time (k-1)ΔT corresponding to data k-1 and before time kΔT corresponding to data k (e.g., time (k-1)ΔT, and time u... lp (t) and C L The time corresponding to the intersection point, etc., is used as the entry time t. i Additionally, the control unit 300 can also calculate the value for u. lp The curve is obtained by interpolating the data included in (t), and the curve and C are calculated. L The time corresponding to the intersection point is taken as t. i t o .

[0199] Additionally, regarding u lp (t) includes C L Consider two consecutive data points, one of which is related to C. L The case of equality. For example, in Figure 15 In the example, consider the value of data k and C L In the case of equality, the control unit 300 can also select to be equal to C. L Equal data and the group of the previous data, and with C L Either the pair of equal data and the pair of subsequent data is used as the sandwich C. L Two consecutive data points. Figure 15 In the example, data k and C LIn the case of equality, the control unit 300 selects either the group of data k-1 and data k, or the group of data k and data k+1, as the pair containing C. L The control unit 300 can also export the time interval between two consecutive data points corresponding to the two data points included in the selected group as t. i or t o .

[0200] In this embodiment, the control unit 300 outputs and u lp The time corresponding to any data point included in (t) is taken as the entry time t. i Exit time t o Therefore, the control unit 300 can refer to u lp (t) and easily obtain and utilize the information including the entry time t i Exit time t o The measurement times corresponding to the ΔT interval are u lp (t) data. In contrast, the control unit 300 derives data related to u. lp The time at which any data included in (t) does not correspond to the entry time t is taken as the entry time. i Exit time t o In this case, by using the original u lp The resampling of (t) and other methods are used to obtain the result including t. i t o The measurement times corresponding to the ΔT interval are u lp The data (t) thus increases the processing time.

[0201] The control unit 300 uses the attenuated u-frequency component above the fundamental frequency. lp (t) Derivation of entry and exit times can reduce the influence of vibration components above the fundamental frequency, thus enabling higher accuracy in deriving entry and exit times.

[0202] However, the control unit 300 may not need to export u. lp (t). In this case, the control unit 300 can, for example, replace u. lp (t) and use u(t) to derive t i t o .

[0203] Furthermore, the control unit 300 outputs a time interval ts of t. o -t i .

[0204] The function of the number derivation unit 305 is based on the environmental information obtained by the environmental information acquisition unit 302 and the baseband F derived by the baseband derivation unit 303. fAnd the passage period t exported through the function of the passage period export unit 304. s Derive the number of railway vehicles included in railway train 6.

[0205] Control unit 300, through the function of number derivation unit 305, determines the vehicle length L of railway cars of railway train 6 based on environmental information. c (m) and fundamental frequency F f And the average speed v of the railway train is derived using equation (41). a Furthermore, in this embodiment, since the railway train 6 consists of identical railway vehicles, L is the same for each of m = 1 to N. c (m) are the same value.

[0206] In addition, the control unit 300 is based on the derived v a L represented by environmental information B and L a And use equation (34) to derive the time t during which a railway vehicle passes over a bridge. c (m). Furthermore, the control unit 300 is based on the derived F... f t s and t c (m), and use equation (42) to derive the number N of railway vehicles that make up a railway train.

[0207] As described above, with the configuration of this embodiment, the derivation system 10 can derive the number of railway vehicles based on the time-series data of the deflection at the observation point and environmental information. Furthermore, the derivation system 10 derives the fundamental frequency Ff from the result of the FFT for u(t), using equation (41) based on the vehicle length L. c (m) and F f Derive the average speed v of the railway train a Using equation (34) based on the derived v a L B and L a Derive the time t during which a railway vehicle crosses a bridge. c (m), using equation (42) based on the derived F f t s and t c (m) Derive the number N of railway cars that make up a railway train. In this way, the derivation system 10 can reduce the amount of computation and calculate the number of railway cars that make up a railway train 6 with a lower workload compared to calculating the number of railway cars that make up a railway train 6 by means of reverse analysis. Thus, the derivation system 10 can calculate the number of railway cars that make up a railway train 6 with a lower workload.

[0208] Furthermore, since the number of railway vehicles is derived with higher precision through the export system 10, the exported number can be used to perform more accurate diagnosis of the bridge. For example, based on the number N derived through the processing of this embodiment, T shown in equation (32) is derived using a flexure model. std (t). Because the number N is derived with higher precision, the deflection T can also be derived with higher precision. std (t). Furthermore, by using the deflection T derived in this way... std (t) enables the high-precision calculation of the impact coefficient on bridges. Using this impact coefficient, bridges can be diagnosed with high accuracy. Therefore, high-precision measurement and vehicle number derivation are effective in dynamic design that incorporates risk factors including resonance phenomena in railway bridges.

[0209] (2) Export processing:

[0210] use Figure 20 The process of deriving the number of railway cars of railway train 6 performed by server device 3 will be explained. Server device 3 starts based on the situation where displacement data at the observation point is sent from measuring device 1. Figure 20 The processing can be initiated at a specified time or any other time. Figure 20 The processing.

[0211] In S100, the control unit 300 acquires the timing data u(t) of the deflection generated at the observation point from the measuring device 1 through the function of the acquisition unit 301. S100 is an example of the acquisition step.

[0212] In S105, the control unit 300 obtains the bridge length L of the unit bridge truss through the function of the environmental information acquisition unit 302. B The length L of each railway car in railway train 6 c , representing the distance L between the positions of each railway car of railway train 6. a The information is used as environmental information. S105 is an example of an environmental information acquisition step.

[0213] In S110, the control unit 300 performs an FFT on u(t) acquired in S100 using the function of the fundamental frequency derivation unit 303. The control unit 300 detects peak values ​​from the FFT result. The control unit 300 determines the lowest frequency among the detected peak values, excluding the sidelobe peaks caused by the window function used in the FFT. The control unit 300 derives the frequency corresponding to the determined peak value as the fundamental frequency F of u(t). f S110 is an example of the baseband derivation step.

[0214] In S115, the control unit 300 derives the base frequency F through the function of the transit-time derivation unit 304.f The reciprocal of the product, thus deriving the period T. f The control unit 300 is based on the derived T... f And ΔT as a given period, and derive k using equation (43). mf Furthermore, the control unit 300 uses equation (44) derived from k mf And u(t) derive u lp (t). Control unit 300 determines the exported u lp (t) and a given threshold C related to the deflection. L The intersection point, i.e., u lp (t)=C L Given two points, derive the earlier of the times corresponding to the determined points as the entry time t. i The later side is taken as the exit time t. o Furthermore, the control unit 300 exports data during the t period. s For t o -t i S115 is an example of a step that is exported during the process.

[0215] In S120, the control unit 300, through the function of the number derivation unit 305, calculates the vehicle length L of the railway cars of the railway train 6 based on the environmental information. c (m) and fundamental frequency F f And the average speed v of the railway train is derived using equation (41). a Additionally, the control unit 300 is based on the derived v a L represented by environmental information B and L a And use equation (34) to derive the time t during which a railway vehicle passes over a bridge. c (m). Furthermore, the control unit 300 is based on the derived F... f t s and t c (m), and use equation (42) to derive the number N of railway cars that make up a railway train. S120 is an example of a number derivation step. In addition, t is derived in S120. c The processing of (m) is an example of the export step during the movement of the body.

[0216] (3) Other implementation methods:

[0217] The above-described embodiments are one example of implementing the present invention, and various other embodiments may also be adopted. The method of deriving the number of railway vehicles of a railway train from the displacement at the observation point, as described above, can also be implemented as an invention of a program or a method.

[0218] Furthermore, the functions of server device 3 can be implemented by multiple devices. Each function of server device 3 can also be distributed across multiple devices. Additionally, each function of server device 3 can be installed in other devices. For example, the functions of acquisition unit 301, environmental information acquisition unit 302, baseband derivation unit 303, transit time derivation unit 304, and count derivation unit 305 can be installed in measurement device 1. The configuration of server device 3 being distributed across multiple devices is also possible. Furthermore, the above embodiment is one example; embodiments that omit some components or add other components are also possible.

[0219] In the above embodiment, the export system 10 exports the number of railway cars included in a railway train 6 consisting of one or more railway cars as moving bodies. However, the export system 10 can also export the number of moving bodies included in other train formations. For example, the export system 10 can also export the number of mine cars included in a train formation consisting of one or more mine cars linked together.

[0220] Furthermore, in the above embodiment, the export system 10 exports the number of movable bodies included in the train that moves on the bridge 5. However, the export system 10 can also export the number of movable bodies included in the train that moves on structures different from the bridge, such as the base of the supporting track.

[0221] In addition, in the above embodiment, the number of sensor devices 2 included in the export system 10 is two, but it can also be one, or more than three.

[0222] In addition, in the above embodiment, the control unit 300 acquires displacement (deflection) data measured from acceleration detected by the accelerometer 210 as time-series data u(t). However, the control unit 300 may also acquire bridge displacement data derived from physical quantities detected by sensors such as impact sensors, pressure sensors, strain gauges, image measuring devices, force sensors, and displacement gauges as u(t). For example, the control unit 300 may periodically photograph a predetermined object positioned at an observation point on the bridge 5 using an image measuring device to detect the displacement of the observation point and acquire the detected displacement data. Furthermore, the control unit 300 may also acquire data of physical quantities different from the bridge displacement as u(t). For example, the control unit 300 may also acquire the number of pixels representing the displacement of a predetermined object positioned at an observation point on the bridge 5 within an image captured by the image measuring device as u(t).

[0223] Furthermore, in the above embodiment, the control unit 300 removes the sidelobes caused by the window function used in the FFT from the FFT result of the time-series data u(t) acquired by the acquisition unit 301, determines the peak value corresponding to the lowest frequency, and calculates the determined peak value as the fundamental frequency F. f However, the control unit 300 can also determine the fundamental frequency F by taking into account the noise generated in the FFT result for u(t). f For example, the control unit 300 can also remove the side lobes caused by the window function used in the FFT from the result of the FFT for u(t), determine the peak value above a predetermined threshold corresponding to the lowest frequency, and calculate the determined peak value as the fundamental frequency F. f .

[0224] Timing data can be obtained at a data rate that is at least twice the frequency of vibrations that would occur in the structure due to the movement of the group of moving bodies.

[0225] Furthermore, the present invention can also be applied to computer-executable programs and methods. In addition, such programs and methods are sometimes implemented as a single device, and sometimes using components of multiple devices, including various other methods. Furthermore, appropriate modifications can be made, for example, making some parts software and others hardware, etc. Furthermore, the invention can also be used as a program recording medium. Of course, the program recording medium can be a magnetic recording medium, a semiconductor memory, etc., and can be considered in the same way in any recording medium developed in the future.

Claims

1. A method for deriving, characterized in that, The export method includes: The acquisition step involves acquiring time-series data of physical quantities generated at predetermined observation points within the structure, wherein the physical quantities are generated as responses caused by the movement of a group of moving bodies consisting of one or more moving bodies on the structure. The environmental information acquisition step involves acquiring the length of the structure, the length of each individual moving body included in the grouped moving body, and the location information of the contact points between the individual moving body and the structure as environmental information. The fundamental frequency derivation step involves deriving the fundamental frequency of the time series data based on the time series data. The process of traversing a convoy is described in the step of deriving the traversal period of the convoy through the structure based on the timing data; and... The number derivation step, based on the environmental information, the base frequency, and the passage period of the grouped mobile bodies, derives the number of individual mobile bodies included in the grouped mobile bodies. The physical quantity is the displacement of the structure. The export method further includes an export step for the passage of a single moving body, wherein the passage period of the single moving body is the period during which the single moving body passes through the structure. In the number derivation step, the product of the value obtained by subtracting the passage period of the individual mobile body from the passage period of the group of mobile bodies and the fundamental frequency, plus 1, is derived as the number of the individual mobile bodies included in the group of mobile bodies.

2. The export method according to claim 1, characterized in that, In the step of deriving the transit period of the troop moving body, the transit time is derived by processing the transit time relative to the structure to obtain the time between one of the two times corresponding to the two data and the time before the other. The transit time is then derived from the transit time to the exit time. The two data are two consecutive data included in the time series data that have been low-pass filtered and sandwiched between predetermined thresholds. The low-pass filtering attenuates the vibration components of the time series data at frequencies above the fundamental frequency.

3. The export method according to claim 1, characterized in that, The contact point is the wheel located on the axle of the single moving body. In the step of exporting during the passage of a single moving body, the value obtained by exporting the sum of the distance between the foremost axle and the last axle of the single moving body and the length of the structure, divided by the product of the fundamental frequency and the length of the single moving body, is taken as the passage period of the single moving body.

4. The export method according to claim 1, characterized in that, In the fundamental frequency derivation step, the frequency corresponding to the lowest peak value among the peak values ​​shown in the Fourier transform results of the time-series data is derived as the fundamental frequency.

5. The derivation method according to any one of claims 1 to 4, characterized in that, The displacement model of the structure is based on the formula of the structure.

6. The derivation method according to any one of claims 1 to 4, characterized in that, The structure is a single-span beam supported at both ends.

7. The derivation method according to any one of claims 1 to 4, characterized in that, The structure in question is a bridge.

8. The derivation method according to any one of claims 1 to 4, characterized in that, The structure can use BWIM, which is Bridge Dynamic Weighing.

9. The derivation method according to any one of claims 1 to 4, characterized in that, The single moving body is a railway vehicle that moves on the structure via wheels.

10. The derivation method according to any one of claims 1 to 4, characterized in that, The time-series data is based on data detected by at least one of an accelerometer, an impact sensor, a pressure sensor, a strain gauge, an image measuring device, a force sensor, and a displacement gauge.

11. An exporting device, characterized in that, The export device includes: The acquisition unit acquires time-series data of physical quantities generated at predetermined observation points within the structure, the physical quantities being generated as responses caused by the movement of a group of moving bodies consisting of one or more moving bodies on the structure. The environmental information acquisition unit acquires the length of the structure, the length of the individual mobile body included in the group of mobile bodies, and the information on the setting position of the contact part of the individual mobile body with the structure as environmental information. The base frequency derivation unit derives the base frequency of the timing data based on the timing data. The time-deriving unit derives the time-passing period of the grouped mobile bodies through the structure based on the time-series data, and derives the time-passing period of a single mobile body, wherein the time-passing period of a single mobile body is the period during which the single mobile body passes through the structure; as well as The number derivation unit, based on the environmental information, the base frequency, and the passage period of the convoy, derives the number of individual mobile bodies included in the convoy. The physical quantity is the displacement of the structure. In the number derivation section, the product of the value obtained by subtracting the passage period of the individual mobile body from the passage period of the group of mobile bodies and the fundamental frequency, plus 1, is derived as the number of the individual mobile bodies included in the group of mobile bodies.

12. An export system comprising an export device and a sensor, characterized in that, The export device includes: The acquisition unit acquires time-series data of physical quantities generated at predetermined observation points within the structure, the physical quantities being generated as responses caused by the movement of a group of moving bodies consisting of one or more moving bodies on the structure, the physical quantities being measured via the sensor. The environmental information acquisition unit acquires the length of the structure, the length of the individual mobile body included in the group of mobile bodies, and the information on the setting position of the contact part of the individual mobile body with the structure as environmental information. The base frequency derivation unit derives the base frequency of the timing data based on the timing data. The time-deriving unit derives the time-passing period of the grouped mobile bodies through the structure based on the time-series data, and derives the time-passing period of a single mobile body, wherein the time-passing period of a single mobile body is the period during which the single mobile body passes through the structure; as well as The number derivation unit, based on the environmental information, the base frequency, and the passage period of the convoy, derives the number of individual mobile bodies included in the convoy. The physical quantity is the displacement of the structure. In the number derivation section, the product of the value obtained by subtracting the passage period of the individual mobile body from the passage period of the group of mobile bodies and the fundamental frequency, plus 1, is derived as the number of the individual mobile bodies included in the group of mobile bodies.

13. A program product, characterized in that, Includes a program that causes a computer to perform the following steps: The acquisition step involves acquiring time-series data of physical quantities generated at predetermined observation points within the structure, wherein the physical quantities are generated as responses caused by the movement of a group of moving bodies consisting of one or more moving bodies on the structure. The environmental information acquisition step involves acquiring the length of the structure, the length of each individual moving body included in the grouped moving body, and the location information of the contact points between the individual moving body and the structure as environmental information. The fundamental frequency derivation step involves deriving the fundamental frequency of the time series data based on the time series data. The process of assemblies passing through a structure is derived based on the timing data. The step of exporting the passage period of a single moving body is to export the passage period of a single moving body, wherein the passage period of a single moving body is the period during which the single moving body passes through the structure; as well as The number derivation step, based on the environmental information, the base frequency, and the passage period of the grouped mobile bodies, derives the number of individual mobile bodies included in the grouped mobile bodies. The physical quantity is the displacement of the structure. In the number derivation step, the product of the value obtained by subtracting the passage period of the individual mobile body from the passage period of the group of mobile bodies and the fundamental frequency, plus 1, is derived as the number of the individual mobile bodies included in the group of mobile bodies.

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