Measurement method, measurement device, measurement system, and measurement program
11408761 · 2022-08-09
Assignee
Inventors
Cpc classification
G01L1/10
PHYSICS
International classification
Abstract
A measurement method includes: a physical quantity acquisition step of acquiring, based on observation information obtained by at least one observation device that observes first to N-th observation points of a structure arranged along a second direction intersecting a first direction in which a moving object moves along the structure, physical quantities at the first to N-th observation points; and an action calculation step of calculating actions x.sub.1 to x.sub.N on the first to N-th observation points based on the acquired physical quantities at the first to N-th observation points, on the assumption that, when a function indicating a correlation between an action x.sub.j on a j-th observation point and an action that the action x.sub.j has on an i-th observation point is set as y.sub.ij, an acquired physical quantity at the i-th observation point is equal to a sum of values of functions y.sub.i1 to y.sub.iN.
Claims
1. A measurement method comprising: a physical quantity acquisition step of acquiring, based on observation information obtained by at least one observation device that observes first to N-th observation points of a structure arranged along a second direction intersecting a first direction in which a moving object moves along the structure, physical quantities at the first to N-th observation points, N being an integer of 2 or more; and an action calculation step of calculating actions x.sub.1 to x.sub.N on the first to N-th observation points based on the physical quantities at the first to N-th observation points acquired in the physical quantity acquisition step, on the assumption that, for any integer i of 1 or more and N or less and any integer j of 1 or more and N or less, when a function indicating a correlation between an action x.sub.j on a j-th observation point and an action that the action x.sub.j has on an i-th observation point is set as y.sub.ij, a physical quantity at the i-th observation point acquired in the physical quantity acquisition step is equal to a sum of values of functions y.sub.i1 to y.sub.iN.
2. The measurement method according to claim 1, further comprising: a coefficient value calculation step of acquiring physical quantities at the first to N-th observation points when a known moving object different from the moving object moves alone on the structure, and calculating a value of a coefficient of the function y.sub.ij based on the physical quantities at the first to N-th observation points.
3. The measurement method according to claim 1, wherein the function y.sub.ij is a polynomial function of the action x.sub.j.
4. The measurement method according to claim 1, wherein the structure has first to N-th paths through which the moving object is able to move, and the first to N-th observation points are associated with the first to N-th paths.
5. The measurement method according to claim 1, wherein the physical quantities at the first to N-th observation points acquired in the physical quantity acquisition step are displacements or loads generated by the moving object.
6. The measurement method according to claim 1, wherein the observation device is an acceleration sensor.
7. The measurement method according to claim 1, wherein the observation device is a contact displacement meter, a ring displacement meter, a laser displacement meter, a pressure sensor, a displacement measurement device based on image processing, or a displacement measurement device based on an optical fiber.
8. The measurement method according to claim 1, wherein the physical quantities at the first to N-th observation points acquired in the physical quantity acquisition step are physical quantities in a third direction intersecting the first direction and the second direction.
9. The measurement method according to claim 1, wherein the moving object is a railroad vehicle, an automobile, a tram, a construction vehicle, or a military vehicle.
10. The measurement method according to claim 1, wherein the structure is a superstructure of a bridge, the superstructure is a structure across any one of a bridge abutment and a bridge pier adjacent to each other, two adjacent bridge abutments, or two adjacent bridge piers, both end portions of the superstructure are located at positions of the bridge abutment and the bridge pier adjacent to each other, at positions of the two adjacent bridge abutments, or at positions of the two adjacent bridge piers, and the bridge is a road bridge or a railway bridge.
11. The measurement method according to claim 1, wherein the structure is a structure in which bridge weigh in motion (BWIM) functions.
12. A measurement device comprising: a physical quantity acquisition unit that acquires, based on observation information obtained by at least one observation device that observes first to N-th observation points of a structure arranged along a second direction intersecting a first direction in which a moving object moves along the structure, physical quantities at the first to N-th observation points, N being an integer of 2 or more; and an action calculation unit that calculates actions x.sub.1 to x.sub.N on the first to N-th observation points based on the physical quantities at the first to N-th observation points acquired by the physical quantity acquisition unit on the assumption that, for any integer i of 1 or more and N or less and any integer j of 1 or more and N or less, when a function indicating a correlation between an action x.sub.j on a j-th observation point and an action that the action x.sub.j has on an i-th observation point is set as y.sub.ij, a physical quantity at the i-th observation point acquired by the physical quantity acquisition unit is equal to a sum of values of functions y.sub.i1 to y.sub.iN.
13. A measurement system comprising: the measurement device according to claim 12; and the observation device.
14. A non-transitory computer-readable storage medium storing a measurement program, the measurement program causing a computer to execute: a physical quantity acquisition step of acquiring, based on observation information obtained by at least one observation device that observes first to N-th observation points of a structure arranged along a second direction intersecting a first direction in which a moving object moves along the structure, physical quantities at the first to N-th observation points, N being an integer of 2 or more; and an action calculation step of calculating actions x.sub.1 to x.sub.N on the first to N-th observation points based on the physical quantities at the first to N-th observation points acquired in the physical quantity acquisition step, on the assumption that, for any integer i of 1 or more and N or less and any integer j of 1 or more and N or less, when a function indicating a correlation between an action x.sub.j on a j-th observation point and an action that the action x.sub.j has on an i-th observation point is set as y.sub.ij, a physical quantity at the i-th observation point acquired in the physical quantity acquisition step is equal to a sum of values of functions y.sub.i1 to y.sub.iN.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF EXEMPLARY EMBODIMENTS
(17) Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below do not in any way limit contents of the present disclosure described in the appended claims. Not all configurations described below are necessarily essential components of the present disclosure.
1. First Embodiment
(18) 1-1. Measurement System
(19) Hereinafter, a measurement system for implementing a measurement method according to the present embodiment will be described by taking a case where a structure is a superstructure of a bridge and a moving object is a vehicle as an example. The vehicle passing through the bridge according to the present embodiment is a vehicle that has a large weight and can be measured by bridge weigh in motion (BWIM), such as a railroad vehicle, an automobile, a tram, a construction vehicle, or a military vehicle. The BWIM is a technology that uses a bridge as a “scale” and that measures the weight and the number of axles of the vehicle passing through the bridge by measuring deformation of the bridge. The superstructure of the bridge, which enables analysis of the weight of the vehicle passing by based on a response such as deformation and strain, is a structure in which the BWIM functions. A BWIM system, which applies a physical process between an action on the superstructure of the bridge and the response, enables the measurement of the weight of the vehicle passing by.
(20)
(21) The bridge 5 includes the superstructure 7 and a substructure 8. The superstructure 7 includes a bridge floor 7a formed of a floor plate F, a main girder G, and a cross girder which is not shown, and bearings 7b. The substructure 8 includes bridge piers 8a and bridge abutments 8b. The superstructure 7 is a structure across any one of the bridge abutment 8b and the bridge pier 8a adjacent to each other, two adjacent bridge abutments 8b, or two adjacent bridge piers 8a. Both end portions of the superstructure 7 are located at positions of the bridge abutment 8b and the bridge pier 8a adjacent to each other, at positions of the two adjacent bridge abutments 8b, or at positions of the two adjacent bridge piers 8a.
(22) The measurement device 1 and each of the sensors 23 are coupled by, for example, a cable which is not shown and communicate with each other via a communication network such as a controller area network (CAN). Alternatively, the measurement device 1 and each of the sensors 23 may communicate with each other via a wireless network.
(23) For example, each sensor 23 outputs data for calculating a displacement of the superstructure 7 due to the movement of the vehicle 6 which is the moving object. In the present embodiment, each of the sensors 23 is an acceleration sensor, and may be, for example, a crystal acceleration sensor or a micro electro mechanical systems (MEMS) acceleration sensor.
(24) In the present embodiment, each sensor 23 is installed at a central portion of the superstructure 7 in the longitudinal direction. Each sensor 23 only needs to be able to detect the acceleration for calculating the displacement of the superstructure 7, and an installation position of each sensor is not limited to the central portion of the superstructure 7.
(25) The floor plate F, the main girder G, and the like of the superstructure 7 are bent in a vertical direction due to a load of the vehicle 6 traveling on the superstructure 7. Each sensor 23 detects the acceleration of the bending of the floor plate F and the main girder G due to the load of the vehicle 6 traveling on the superstructure 7.
(26) The measurement device 1 calculates, based on acceleration data output from the sensors 23, the displacement of the bending of the superstructure 7 due to the traveling of the vehicle 6. The measurement device 1 calculates a load of the vehicle 6 traveling on the superstructure 7 based on the calculated displacement.
(27) The measurement device 1 and the server 2 can communicate with each other via, for example, a wireless network of a mobile phone and a communication network 4 such as the Internet. The measurement device 1 transmits, to the server 2, information such as a time point when the vehicle 6 travels on the superstructure 7 and the displacement of the superstructure 7 due to the traveling of the vehicle 6. The server 2 may store the information in a storage device which is not shown, and may perform, based on the information, processing such as monitoring of an overloaded vehicle or determination of an abnormality in the superstructure 7.
(28) In the present embodiment, the bridge 5 is a road bridge, for example, a steel bridge, a girder bridge, or a reinforced-concrete (RC) bridge.
(29)
(30) As shown in
(31) In the example shown in
(32) When the sensors 23 are provided on the floor plate F of the superstructure 7, the sensors may be destroyed by a traveling vehicle, and measurement accuracy may be affected by local deformation of the bridge floor 7a. Therefore, in the example shown in
(33) In the present embodiment, N observation points R.sub.1 to R.sub.N are set in association with the N sensors 23. The observation points R.sub.1 to R.sub.N are N observation points of the superstructure 7 which are arranged along a second direction intersecting a first direction in which the vehicle 6 moves along the superstructure 7. In the example shown in
(34) In the present embodiment, N observation points R.sub.1 to R.sub.N are associated with the lanes L.sub.1 to L.sub.N, respectively. In the example shown in
(35) The number and installation positions of the sensors 23 are not limited to the example shown in
(36) The measurement device 1 acquires, based on the acceleration data output from each of the sensors 23, an acceleration in a third direction which intersects the X direction, which is the first direction, and the Y direction, which is the second direction. Since the observation points R.sub.1 to R.sub.N bend in the direction orthogonal to the X and Y directions, in order to accurately calculate a magnitude of the acceleration of the bending, it is desirable for the measurement device 1 to acquire an acceleration in the third direction orthogonal to the X direction and the Y direction, that is, in a normal direction of the floor plate F.
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(38) In order to detect the acceleration of the bending at the observation points R.sub.1 to R.sub.N due to the traveling of the vehicle 6, each sensor 23 is installed such that one of three detection axes, which are an x axis, a y axis, and a z axis, intersects the first direction and the second direction. In the example shown in
(39) When the sensors 23 are installed on the superstructure 7, an installation location may be inclined. In the measurement device 1, even if one of the three detection axes of each of the sensors 23 is not installed in the normal direction of the floor plate F, since the direction is substantially oriented in the normal direction, an error is small and thus can be ignored. Even if one of the three detection axes of each sensor 23 is not installed in the normal direction of the floor plate F, the measurement device 1 can correct a detection error caused by the inclination of the sensor 23 by a three-axis combined acceleration obtained by combining accelerations in the x axis, the y axis, and the z axis. Each of the sensors 23 may be a one-axis acceleration sensor that detects an acceleration generated in a direction at least substantially parallel to the vertical direction or the acceleration in the normal direction of the floor plate F.
(40) Hereinafter, details of the measurement method according to the present embodiment executed by the measurement device 1 will be described.
(41) 1-2. Calculation of Action
(42) When the vehicle 6 travels on the lane L.sub.1, an action x.sub.1 occurs at the observation point R.sub.1 due to a load generated by the vehicle 6. Therefore, the observation point R.sub.1 is displaced due to the action x.sub.1. At this time, when the vehicle 6 travels alone on the superstructure 7, the action generated at the observation points R.sub.2 to R.sub.N by the load due to the vehicle traveling in the lanes L.sub.2 to L.sub.N is zero. However, since the action x.sub.1 has an effect on the observation points R.sub.2 to R.sub.N, the observation points R.sub.2 to R.sub.N are also displaced. Therefore, not only the sensor 23 that observes the observation point R.sub.1 but also the N−1 sensors 23 that respectively observe the observation points R.sub.2 to R.sub.N detect accelerations generated by the vehicle traveling on the lane L.sub.1.
(43) As an example,
(44)
(45)
(46) A peak PK1 of the acceleration data output from the sensor 23 that observes the observation point R.sub.1 indicates passage of an axle of the vehicle 6.
(47) The peak PK1 of the acceleration data output from the sensor 23 that observes the observation point R.sub.1 corresponds to the action x.sub.1 on the observation point R.sub.1 generated by the vehicle 6. On the other hand, a peak PK2 of the acceleration data output from the sensor 23 that observes the observation point R.sub.2 corresponds to an action that the action x.sub.1 on the observation point R.sub.1 generated by the vehicle 6 has on the observation point R.sub.2. The peak PK1 is greater than the peak PK2 since the vehicle 6 travels alone on the lane L.sub.1.
(48) When the vehicle 6 travels on the lane L.sub.1 and the other vehicle 6 travels on the lane L.sub.2 adjacently, the sensor 23 that observes the observation point R.sub.1 detects an acceleration corresponding to a sum of the action x.sub.1 on the observation point R.sub.1 generated by the vehicle 6 traveling on the lane L.sub.1 and an action that the action x.sub.2 on the observation point R.sub.2 generated by another vehicle 6 traveling on the lane L.sub.2 has on the observation point R.sub.1. Similarly, the sensor 23 that observes the observation point R.sub.2 detects an acceleration corresponding to a sum of the action x.sub.2 on the observation point R.sub.2 generated by another vehicle 6 traveling on the lane L.sub.2 and an action that the action x.sub.1 on the observation point R.sub.1 generated by the vehicle 6 traveling on the lane L.sub.1 has on the observation point R2. Therefore, when two vehicles 6 travel adjacently, the peaks PK1 and PK2 are all greater than those in the example of
(49) On the other hand, when the vehicle 6 travels alone as in the example in
(50) First, a function y.sub.ij indicating the correlation between the action x.sub.j on the observation point R when the vehicle 6 travels on the lane L.sub.j and the action that the action x.sub.j on the observation point R has on the observation point R.sub.1 is defined as in Equation (1). Each of j and i is any integer of 1 or more and N or less. In Equation (1), a.sub.ij is a first-order coefficient, and b.sub.ij is a zero-order coefficient. As shown in Equation (1), the function y.sub.ij is a polynomial function of action x.sub.j, specifically a first-order polynomial function.
(51) For example, as an example, the case of N=2 is taken as an example as in the arrangement example shown in
y.sub.ij=a.sub.ijx.sub.j+b.sub.ij (1)
(52) As an example, a function y.sub.i1 indicating a correlation between the action x.sub.1 on the observation point R.sub.1 and an action that the action x.sub.1 has on the observation point R.sub.i is defined as in Equation (2).
y.sub.i1=a.sub.i1x.sub.1+b.sub.i1 (1)
(53) More specifically, functions y.sub.i1 to y.sub.N1 that indicate correlations between the action x.sub.1 and actions that the action x.sub.1 has on the observation points R.sub.1 to R.sub.N are as shown in Equation (3), respectively.
(54)
(55) Next, as shown in Equation (4), a displacement g.sub.i at the observation point R.sub.1 is assumed to be equal to a sum of values of the functions y.sub.i1 to y.sub.iN.
g.sub.i=y.sub.i1+y.sub.i2+ . . . +y.sub.iN (4)
(56) At this time, according to Equations (1) and (4), a displacement vector g having the displacements g.sub.1 to g.sub.N at the observation points R.sub.1 to R.sub.N as elements is expressed as Equation (5).
(57)
(58) In Equation (5), each element y.sub.k of a vector Y is defined as in Equation (6). k is any integer of 1 or more and N or less.
(59)
(60) When it is assumed that a displacement vector u having actually observed displacements u.sub.1 to u.sub.N at the observation points R.sub.1 to R.sub.N as elements is equal to the displacement vector g, Equation (7) is obtained. The displacements u.sub.1 to u.sub.N are obtained, for example, by integrating the accelerations detected by the N sensors 23 corresponding to the observation points R.sub.1 to R.sub.N twice.
{right arrow over (u)}={right arrow over (g)}=A.Math.{right arrow over (X)}+B.Math.{right arrow over (Y)} (7)
(61) Equation (8) is obtained by transforming Equation (7)
(62)
(63) When a first-order coefficient matrix A and a zero-order coefficient matrix B are known, by substituting the displacement vector u obtained by the observation into Equation (8), an action vector X having unknown actions x.sub.1 to x.sub.N as elements is calculated.
(64) As an example, a process of deriving the actions x.sub.1 and x.sub.2 based on the Equation (8) will be described in detail by taking the case of N=2 as an example as in the arrangement example shown in
(65)
(66) Equation (10) is obtained by transforming Equation (9).
(67)
(68) According to Equation (10), the actions x.sub.1 and x.sub.2 are calculated as in Equations (11) and (12), respectively.
(69)
(70)
(71) As shown in
(72) In contrast,
(73) As shown in
(74) 1-3. Measurement Method
(75)
(76) As shown in
(77) Next, based on observation information obtained by the N sensors 23 that observe the observation points R.sub.1 to R.sub.N, the measurement device 1 acquires the displacements u.sub.1 to u.sub.N as physical quantities at the observation points R.sub.1 to R.sub.N when the vehicle 6 moves on the superstructure 7 (step S2). As described above, the N sensors 23 are acceleration sensors. The observation information obtained by the N sensors 23 is detection information on the accelerations generated at the observation points R.sub.1 to R.sub.N. Then, the acceleration is an acceleration in the third direction which intersects the X direction, which is the first direction, and the Y direction, which is the second direction. The measurement device 1 integrates the acceleration in the third direction detected by each of the N sensors 23 twice to calculate the displacement vector u included in the above Equation (8). Therefore, the displacements u.sub.1 to u.sub.N as the physical quantities at the observation points R.sub.1 to R.sub.N acquired by the measurement device 1 in a physical quantity acquisition step are displacements in the third direction intersecting the X and Y directions, respectively, for example, displacements in the third direction that is orthogonal to the X and Y directions, respectively. The step S2 is the physical quantity acquisition step.
(78) Next, the measurement device 1 calculates the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N based on the displacements u.sub.1 to u.sub.N acquired in step S2, on the assumption that the displacement u.sub.1 at the observation point R.sub.1 is equal to the sum of the values of the functions y.sub.i1 to y.sub.iN (step S3). i is any integer of 1 or more and N or less. Specifically, the measurement device 1 calculates the action vector X by substituting the inverse matrix A.sup.−1 of the first-order coefficient matrix A and the zero-order coefficient matrix B which are calculated in step S1 and the displacement vector u calculated in step S2 into the above Equation (8). The step S3 is an action calculation step.
(79) Next, based on the actions x.sub.1 to x.sub.N calculated in step S3, the measurement device 1 calculates displacements u′.sub.1 to u′.sub.N at the observation points R.sub.1 to R.sub.N (step S4). For example, for each integer j of 1 or more and N or less, a displacement g.sub.j calculated assuming that all actions among the actions x.sub.1 to x.sub.N except the action x.sub.j in the right-hand side of the above Equation (5) are zero is defined as a displacement u′.sub.j. The step S4 is a displacement calculation step.
(80) Next, based on the displacements u′.sub.1 to u′.sub.N calculated in step S4, the measurement device 1 calculates the load generated by the vehicle 6 traveling on each of the lanes L.sub.1 to L.sub.N (step S5). For each integer j of 1 or more and N or less, since there is a correlation between the displacement u′.sub.j and the load generated by the vehicle 6 traveling on the lane L.sub.j, a coefficient of a correlation equation is calculated in advance in a load test of a vehicle. The measurement device 1 can calculate the load generated by the vehicle 6 traveling on the lane L.sub.j by substituting the displacement u′.sub.j into the correlation equation. The step S5 is a load calculation step.
(81) Next, the measurement device 1 outputs the loads generated by the vehicle 6 traveling on the lanes L.sub.1 to L.sub.N calculated in step S5 to the server 2 (step S6). The step S6 is an output step.
(82) The measurement device 1 repeats the processing in steps S2 to S6 until the measurement is completed (Y in step S7).
(83)
(84) As shown in
(85) Next, the measurement device 1 performs first-order approximation on a correlation between the acceleration at the observation point R.sub.j and the acceleration at each of the observation points R.sub.1 to R.sub.N acquired in step S12, and calculates values of first-order coefficients a.sub.1j to a.sub.Nj and values of zero-order coefficients b.sub.ij to b.sub.Nj (step S13).
(86) When the integer j is not N (N in step S14), the measurement device 1 adds 1 to the integer j (step S15), and repeats the processing in steps S11 to S13.
(87) Then, when the integer j is N (Y in step S14), the measurement device 1 generates the first-order coefficient matrix A having the first-order coefficients a.sub.11 to a.sub.NN calculated in step S13 as elements and the zero-order coefficient matrix B having the zero-order coefficients b.sub.11 to b.sub.NN calculated in step S13 as elements (step S16). The first-order coefficient matrix A and the zero-order coefficient matrix B are matrices included in the above Equation (5).
(88) Finally, the measurement device 1 generates the inverse matrix A.sup.−1 of the first-order coefficient matrix A (step S17), and ends the processing of the coefficient value calculation step.
(89) 1-4. Configuration of Measurement Device
(90)
(91) The control unit 110 calculates the displacement or the like of the superstructure 7 based on the acceleration data output from each of the sensors 23 installed in the superstructure 7.
(92) The first communication unit 120 receives the acceleration data from each of the sensors 23. The acceleration data output from each of the sensors 23 is, for example, a digital signal. The first communication unit 120 outputs, to the control unit 110, the acceleration data received from each of the sensors 23.
(93) The storage unit 130 is a memory that stores a program, data, and the like for the control unit 110 to perform calculation processing and control processing. In addition, the storage unit 130 stores a program, data, and the like for the control unit 110 to implement a predetermined application function. The storage unit 130 is implemented by, for example, various integrated circuit (IC) memories such as a read only memory (ROM), a flash ROM, and a random access memory (RAM), and a recording medium such as a hard disk and a memory card.
(94) The storage unit 130 includes a non-volatile information storage device that is a device or a medium that can be read by a computer. Various programs, data, and the like may be stored in the information storage device. The information storage device may be an optical disk such as an optical disk DVD or a CD, a hard disk drive, or various types of memories such as a card-type memory or a ROM. In addition, the control unit 110 may receive various programs, data, and the like via the communication network 4 and store the programs, the data, and the like in the storage unit 130.
(95) The second communication unit 140 transmits information such as a calculation result of the control unit 110 to the server 2 via the communication network 4.
(96) The operation unit 150 acquires operation data from the user and transmits the operation data to the control unit 110.
(97) The control unit 110 includes a physical quantity acquisition unit 111, an action calculation unit 112, a displacement calculation unit 113, a load calculation unit 114, a coefficient value calculation unit 115, and an output processing unit 116.
(98) Based on the observation information obtained by the N sensors 23 that observe the observation points R.sub.1 to R.sub.N, the physical quantity acquisition unit 111 acquires the displacements u.sub.1 to u.sub.N as the physical quantities at the observation points R.sub.1 to R.sub.N when the vehicle 6 moves on the superstructure 7. That is, the physical quantity acquisition unit 111 performs the processing of the physical quantity acquisition step in
(99) The action calculation unit 112 calculates the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N based on the displacements u.sub.1 to u.sub.N acquired by the physical quantity acquisition unit 111, on the assumption that the displacement u.sub.1 at the observation point R.sub.1 is equal to the sum of the values of the functions y.sub.i1 to y.sub.iN for any integer i of 1 or more and N or less. That is, the action calculation unit 112 performs the processing of the action calculation step in
(100) Based on the actions x.sub.1 to x.sub.N calculated by the action calculation unit 112, the displacement calculation unit 113 calculates the displacements u′.sub.1 to u′.sub.N at the observation points R.sub.1 to R.sub.N. That is, the displacement calculation unit 113 performs the processing of the displacement calculation step in
(101) Based on the displacements u′.sub.1 to u′.sub.N calculated by the displacement calculation unit 113, the load calculation unit 114 calculates the load generated by the vehicle 6 traveling on each of the lanes L.sub.1 to L.sub.N. That is, the load calculation unit 114 performs the processing of the load calculation step in
(102) For any integers i and j of 1 or more and N or less, the coefficient value calculation unit 115 acquires the displacements u.sub.1 to u.sub.N at the observation points R.sub.1 to R.sub.N when the vehicle travels alone on the superstructure 7, and calculates, based on the displacements u.sub.1 to u.sub.N, the values of the coefficients a.sub.ij and b.sub.ij of the function y.sub.ij. That is, the coefficient value calculation unit 115 performs the processing of the coefficient value calculation step in
(103) The output processing unit 116 performs processing of outputting the loads of the vehicle 6 traveling on the lanes L.sub.1 to L.sub.N calculated by the load calculation unit 114 to the server 2 via the second communication unit 140. That is, the output processing unit 116 performs the processing of the output step in
(104) For example, based on the operation data from the operation unit 150, the control unit 110 switches between a first mode for calculating the displacement of the superstructure 7 generated by the unknown vehicle 6, and a second mode for calculating the first-order coefficients a.sub.11 to a.sub.NN and the zero-order coefficients b.sub.11 to b.sub.NN. For example, after the N sensors 23 are installed in the superstructure 7, a load test of a plurality of vehicles is performed in a state in which the control unit 110 is set to the second mode. After the load test ends, the control unit 110 is set to the first mode.
(105) In the present embodiment, the control unit 110 is a processor that executes various programs stored in the storage unit 130. By executing a measurement program 131 stored in the storage unit 130, functions of the physical quantity acquisition unit 111, the action calculation unit 112, the displacement calculation unit 113, the load calculation unit 114, the coefficient value calculation unit 115, and the output processing unit 116 are implemented. In other words, the measurement program 131 is a program that causes the measurement device 1, which is a computer, to execute each procedure in the flowchart shown in
(106) In the processor, for example, a function of each part may be implemented by individual hardware, or the functions of the respective parts may be implemented by integrated hardware. For example, the processor may include hardware. The hardware may include at least one of a circuit for processing the digital signal and a circuit for processing an analog signal. The processor may be a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), or the like. The control unit 110 is implemented as a custom integrated circuit (IC) such as an application specific integrated circuit (ASIC), and may implement the function of each part, or may implement the function of each part by the CPU and the ASIC.
(107) The control unit 110 may not include the load calculation unit 114. The control unit 110 may not include the coefficient value calculation unit 115. For example, the server 2 or another device may perform processing of calculating the values of the first-order coefficients a.sub.11 to a.sub.NN and the values of the zero-order coefficients b.sub.11 to b.sub.NN, and store the values in the storage unit 130 of the measurement device 1.
(108) 1-5. Operation Effects
(109) In the measurement method according to the first embodiment described above, based on the observation information obtained by the N sensors 23 that observe the observation points R.sub.1 to R.sub.N, the measurement device 1 acquires the displacements u.sub.1 to u.sub.N as the physical quantities at the observation points R.sub.1 to R.sub.N. Then, on the assumption that, when a function indicating a correlation between the action x.sub.j on the observation point R.sub.j and the action that the action x.sub.j has on the observation point R.sub.1 is set as y.sub.ij, the displacement u.sub.i is equal to the sum of the values of the functions y.sub.i1 to y.sub.iN, the measurement device 1 calculates the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N according to Equation (8) and based on the displacements u.sub.1 to u.sub.N. Therefore, according to the measurement method in the first embodiment, the measurement device 1 can calculate the action x.sub.j when the vehicle 6, which is a moving object, passes the observation point R.sub.j of the superstructure 7, which is a structure, separately from other actions. For example, even when a plurality of vehicles 6 travel adjacently on a plurality of lanes, the measurement device 1 can calculate the action x.sub.j on the observation point R.sub.j generated by the vehicle 6 traveling on the lane L by excluding the influence of the action on the observation point R.sub.j that the action x.sub.i on the observation point R.sub.i generated by the vehicle 6 traveling on the lane L.sub.i has.
(110) In the measurement method according to the first embodiment, the measurement device 1 calculates the displacements u′.sub.1 to u′.sub.N at the observation points R.sub.1 to R.sub.N based on the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N, and calculates the loads generated by the vehicle 6 at the observation points R.sub.1 to R.sub.N based on the displacements u′.sub.1 to u′.sub.N. Therefore, according to the measurement method in the first embodiment, the measurement device 1 can accurately calculate, based on the action x.sub.j on the observation point R.sub.j which is calculated separately from other actions, the displacement and the load at the observation point R.sub.j generated by the traveling of the vehicle 6. For example, even when a plurality of vehicles travel adjacently on the plurality of lanes, the measurement device 1 can accurately calculate the displacement and the load at the lane L.sub.j generated by the vehicle 6 moving along the lane L.sub.j. Based on the information on the displacement and the load, for example, the measurement device 1 or the server 2 can accurately perform processing such as monitoring of an overloaded vehicle and abnormality determination of the superstructure 7.
(111) According to the measurement method in the first embodiment, since the measurement device 1 can calculate the displacement of the superstructure 7 caused by the axle load of the vehicle 6 passing through the superstructure 7 and the load of the vehicle 6, sufficient information can be provided for maintenance and management of the bridge 5 to predict the damage of the superstructure 7.
2. Second Embodiment
(112) In the measurement method according to the first embodiment, in the physical quantity acquisition step, the measurement device 1 acquires the displacements u.sub.1 to u.sub.N at the observation points R.sub.1 to R.sub.N as the physical quantities at the observation points R.sub.1 to R.sub.N. Meanwhile, in a measurement method according to a second embodiment, in a physical quantity acquisition step, the measurement device 1 acquires loads w.sub.1 to w.sub.N at the observation points R.sub.1 to R.sub.N generated by the vehicle 6 as the physical quantities at the observation points R.sub.1 to R.sub.N. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals for the second embodiment, and the description repeated with that in the first embodiment will be omitted or simplified, and different contents from those of the first embodiment will be mainly described.
(113) As shown in Equation (13), a load f.sub.i at the observation point R.sub.1 generated by the vehicle 6 is assumed to be equal to a sum of the values of the above described functions y.sub.i1 to y.sub.iN.
f.sub.i=y.sub.i1+y.sub.i2+ . . . +y.sub.iN (13)
(114) At this time, according to Equations (1) and (13), a load vector f having loads f.sub.1 to f.sub.N at the observation points R.sub.1 to R.sub.N generated by the vehicle 6 as elements is expressed as Equation (14).
(115)
(116) In Equation (14), each element y.sub.k of a vector Y is defined as in Equation (15). k is any integer of 1 or more and N or less.
(117)
(118) When it is assumed that a load vector w having the actually observed loads w.sub.1 to w.sub.N at the observation points R.sub.1 to R.sub.N generated by the vehicles 6 as elements is equal to the load vector f, Equation (16) is obtained.
{right arrow over (w)}={right arrow over (f)}=A.Math.{right arrow over (X)}+B.Math.{right arrow over (Y)} (16)
(119) Equation (17) is obtained by transforming Equation (16).
(120)
(121) When a first-order coefficient matrix A and a zero-order coefficient matrix B are known, by substituting the load vector w obtained by the observation into Equation (17), an action vector X having unknown actions x.sub.1 to x.sub.N as elements is calculated.
(122) As an example, a process of deriving the actions x.sub.1 and x.sub.2 based on Equation (17) will be described in detail by taking the case of N=2 as an example as in the above-described arrangement example shown in
(123)
(124) Equation (19) is obtained by transforming Equation (18).
(125)
(126) According to Equation (19), the actions x.sub.1 and x.sub.2 are calculated as in Equations (20) and (21), respectively.
(127)
(128)
(129) As shown in
(130) Next, based on the observation information obtained by the N sensors 23 that observe the observation points R.sub.1 to R.sub.N, the measurement device 1 acquires the loads w.sub.1 to w.sub.N generated by the vehicle 6 as the physical quantities at the observation points R.sub.1 to R.sub.N when the vehicle 6 moves on the superstructure 7 (step S102). As described above, the N sensors 23 are acceleration sensors. The observation information obtained by the N sensors 23 is detection information on the accelerations generated at the observation points R.sub.1 to R.sub.N. Then, the acceleration is an acceleration in the third direction which intersects the X direction, which is the first direction, and the Y direction, which is the second direction. The measurement device 1 calculates the load vector w included in Equation (17) based on the acceleration in the third direction detected by each of the N sensors 23. Therefore, the loads w.sub.1 to w.sub.N as the physical quantities at the observation points R.sub.1 to R.sub.N acquired by the measurement device 1 in a physical quantity acquisition step are loads in the third direction intersecting the X and Y directions, respectively, for example, loads in the third direction that is orthogonal to the X and Y directions, respectively. The step S102 is the physical quantity acquisition step.
(131) Next, assuming that the load w.sub.i generated by the vehicle 6 at the observation point R.sub.i is equal to the sum of the values of the functions y.sub.i1 to y.sub.iN, and based on the loads w.sub.1 to w.sub.N acquired in step S102, the measurement device 1 calculates the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N (step S103). i is any integer of 1 or more and N or less. Specifically, the measurement device 1 calculates the action vector X by substituting the inverse matrix A.sup.−1 of the first-order coefficient matrix A and the zero-order coefficient matrix B which are calculated in step S101 and the load vector w calculated in step S102 into Equation (17). The step S103 is an action calculation step.
(132) Next, based on the actions x.sub.1 to x.sub.N calculated in step S103, the measurement device 1 calculates loads w′.sub.1 to w′.sub.N at the observation points R.sub.1 to R.sub.N generated by the vehicle 6 (step S104). For example, for each integer j of 1 or more and N or less, a load f.sub.j calculated assuming that all actions among the actions x.sub.1 to x.sub.N except the action x.sub.j in the right-hand side of Equation (14) are zero is defined as a load w′.sub.j. The step S104 is a load calculation step.
(133) Next, based on the loads w′.sub.1 to w′.sub.N calculated in step S104, the measurement device 1 calculates the displacement at each of the lanes L.sub.1 to L.sub.N generated by the traveling of the vehicle 6 (step S105). For each integer j of 1 or more and N or less, since there is a correlation between the load w′.sub.j and the displacement at the lane L.sub.j, a coefficient of a correlation equation is calculated in advance in a load test of a vehicle. The measurement device can calculate the displacement at the lane L.sub.j by substituting the load w′.sub.j into the correlation equation. The step S105 is a displacement calculation step.
(134) Next, the measurement device 1 outputs the displacements at the lanes L.sub.1 to L.sub.N calculated in step S105 to the server 2 (step S106). The step S106 is an output step.
(135) The measurement device 1 repeats the processing in steps S102 to S106 until the measurement is completed (Y in step S107).
(136) The configuration of the measurement device 1 according to the second embodiment is the same as that in
(137) Since the processing performed by the first communication unit 120, the storage unit 130, the second communication unit 140, and the operation unit 150 are the same as that in the first embodiment, the description thereof will be omitted.
(138) The control unit 110 calculates the load generated by the vehicle 6 or the like based on the acceleration data output from each of the sensors 23 installed in the superstructure 7. Similar to the first embodiment, the control unit 110 includes the physical quantity acquisition unit 111, the action calculation unit 112, the displacement calculation unit 113, the load calculation unit 114, the coefficient value calculation unit 115, and the output processing unit 116.
(139) Based on the observation information obtained by the N sensors 23 that observe the observation points R.sub.1 to R.sub.N, the physical quantity acquisition unit 111 acquires the loads w.sub.1 to w.sub.N generated by the vehicle 6 as the physical quantities at the observation points R.sub.1 to R.sub.N when the vehicle 6 moves on the superstructure 7. That is, the physical quantity acquisition unit 111 performs the processing of the physical quantity acquisition step in FIG. 16. The loads w.sub.1 to w.sub.N acquired by the physical quantity acquisition unit 111 are stored in the storage unit 130.
(140) Based on the loads w.sub.1 to w.sub.N acquired by the physical quantity acquisition unit 111, on the assumption that, for any integer i of 1 or more and N or less, the load w.sub.1 at the observation point R.sub.1 generated by the vehicle 6 is equal to the sum of the values of the functions y.sub.i1 to y.sub.iN, the action calculation unit 112 calculates the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N. That is, the action calculation unit 112 performs the processing of the action calculation step in
(141) Based on the loads w′.sub.1 to w′.sub.N calculated by the load calculation unit 114, the displacement calculation unit 113 calculates the displacement at each of the lanes L.sub.1 to L.sub.N generated by the traveling of the vehicle 6. That is, the displacement calculation unit 113 performs the processing of the displacement calculation step in
(142) Based on the actions x.sub.1 to x.sub.N calculated by the action calculation unit 112, the load calculation unit 114 calculates the loads w′.sub.1 to w′.sub.N generated by the vehicle 6 at the observation points R.sub.1 to R.sub.N. That is, the load calculation unit 114 performs the processing of the load calculation step in
(143) For any integers i and j of 1 or more and N or less, the coefficient value calculation unit 115 acquires the loads w.sub.1 to w.sub.N at the observation points R.sub.1 to R.sub.N generated by the vehicle when the vehicle travels alone on the superstructure 7, and calculates, based on the loads w.sub.1 to w.sub.N, the values of the coefficients a.sub.ij and b.sub.ij of the function y.sub.ij. That is, the coefficient value calculation unit 115 performs the processing of the coefficient value calculation step in
(144) The output processing unit 116 performs processing of outputting the displacements at the lanes L.sub.1 to L.sub.N calculated by the displacement calculation unit 113 to the server 2 via the second communication unit 140. That is, the output processing unit 116 performs the processing of the output step in
(145) For example, based on the operation data from the operation unit 150, the control unit 110 switches between a first mode for calculating the load generated by the unknown vehicle 6, and a second mode for calculating the first-order coefficients a.sub.11 to a.sub.NN and the zero-order coefficients b.sub.11 to b.sub.NN. For example, after the N sensors 23 are installed in the superstructure 7, the load test of a plurality of vehicles is performed in a state in which the control unit 110 is set to the second mode. After the load test ends, the control unit 110 is set to the first mode.
(146) Similar to the first embodiment, the control unit 110 is a processor that executes various programs stored in the storage unit 130. By executing the measurement program 131 stored in the storage unit 130, functions of the physical quantity acquisition unit 111, the action calculation unit 112, the displacement calculation unit 113, the load calculation unit 114, the coefficient value calculation unit 115, and the output processing unit 116 are implemented. In other words, the measurement program 131 is a program that causes the measurement device 1, which is a computer, to execute each procedure in the flowchart shown in
(147) The control unit 110 may not include the displacement calculation unit 113. The control unit 110 may not include the coefficient value calculation unit 115. For example, the server 2 or another device may perform processing of calculating the values of the first-order coefficients a.sub.11 to a.sub.NN and the values of the zero-order coefficients b.sub.11 to b.sub.NN, and store the values in the storage unit 130 of the measurement device 1.
(148) In the measurement method according to the second embodiment described above, based on the observation information obtained by the N sensors 23 that observe the observation points R.sub.1 to R.sub.N, the measurement device 1 acquires the loads w.sub.1 to w.sub.N generated by the vehicle 6 as the physical quantities at the observation points R.sub.1 to R.sub.N. Then, on the assumption that, when a function indicating a correlation between the action x.sub.j on the observation point R.sub.j and the action that the action x.sub.j has on the observation point R.sub.i is set as y.sub.ij, the load w.sub.i is equal to the sum of the values of the functions y.sub.i1 to y.sub.iN, the measurement device 1 calculates the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N according to Equation (17) and based on the loads w.sub.1 to w.sub.N. Therefore, according to the measurement method in the second embodiment, the measurement device 1 can calculate the action x.sub.j when the vehicle 6, which is a moving object, passes the observation point R.sub.j of the superstructure 7, which is a structure, separately from other actions. For example, even when a plurality of vehicles 6 travel adjacently on a plurality of lanes, the measurement device 1 can calculate the action x.sub.j on the observation point R.sub.j generated by the vehicle 6 traveling on the lane L by excluding the influence of the action on the observation point R.sub.j that the action x.sub.1 on the observation point R.sub.1 generated by the vehicle 6 traveling on the lane L.sub.1 has.
(149) In the measurement method according to the second embodiment, the measurement device 1 calculates, based on the actions x.sub.1 to x.sub.N on the observation points R.sub.1 to R.sub.N, the loads w′.sub.1 to w′.sub.N at the observation points R.sub.1 to R.sub.N generated by the vehicle 6, and calculates the displacements at the observation points R.sub.1 to R.sub.N based on the loads w′.sub.1 to w′.sub.N. Therefore, according to the measurement method in the second embodiment, the measurement device 1 can accurately calculate, based on the action x.sub.j on the observation point R.sub.j which is calculated separately from other actions, the load and the displacement at the observation point R.sub.j generated by the traveling of the vehicle 6. For example, even when a plurality of vehicles 6 travel adjacently on the plurality of lanes, the measurement device 1 can accurately calculate the load and the displacement at the lane L generated by the vehicle 6 moving along the lane L.sub.j. Based on the information on the load and the displacement, for example, the measurement device 1 or the server 2 can accurately perform processing such as monitoring of an overloaded vehicle and abnormality determination of the superstructure 7.
3. Modifications
(150) The present disclosure is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present disclosure.
(151) In each of the embodiments described above, the function y.sub.ij indicating the correlation between the action x.sub.j on the observation point R when the vehicle 6 travels on the lane L.sub.j and the action that the action x.sub.j on the observation point R has on the observation point R.sub.1 is set to a first-order polynomial function shown in Equation (1), but when the correlation is not a straight line, the function y.sub.ij may be an m-order polynomial function as shown in Equation (22).
y.sub.ij=a.sub.m.sub.
(152) In each of the above embodiments, the observation devices that observe the observation points R.sub.1 to R.sub.N are acceleration sensors, but the present disclosure is not limited thereto. For example, the observation device may be a contact displacement meter, a ring displacement meter, a laser displacement meter, a pressure sensor, a displacement measurement device based on image processing, or a displacement measurement device based on an optical fiber. It is not necessary that the observation device and the observation point have a one-to-one correspondence, and one observation device may observe a part or all of the observation points R.sub.1 to R.sub.N.
(153) The contact displacement meter, the ring displacement meter, the laser displacement meter, the displacement measurement device based on image processing, or the displacement measurement device based on an optical fiber measure a displacement as a response to the action on each of the observation points R.sub.1 to R.sub.N generated by the vehicle 6. The measurement device 1 calculates, based on the displacements at the observation points R.sub.1 to R.sub.N, displacements or loads generated by the vehicle 6 as physical quantities at the observation points R.sub.1 to R.sub.N. The pressure sensor detects a stress change as a response to the action on each of the observation points R.sub.1 to R.sub.N generated by the vehicle 6. The measurement device 1 calculates, based on the stress changes at the observation points R.sub.1 to R.sub.N, displacements or loads generated by the vehicle 6 as the physical quantities at the observation points R.sub.1 to R.sub.N.
(154) In each of the above embodiments, the traveling directions of the vehicles 6 on the lanes L.sub.1 to L.sub.N are all the same, but the traveling direction of the vehicle 6 on at least one lane of the lanes L.sub.1 to L.sub.N may be different from those on other lanes.
(155) In each of the above embodiments, the sensor 23 is provided on the main girder G of the superstructure 7, but the sensor may be provided on the surface or inside of the superstructure 7, a lower surface of the floor plate F, the bridge pier 8a, or the like. In each of the above embodiments, the road bridge is taken as an example of the bridge 5, but the present disclosure is not limited thereto. For example, the bridge 5 may be a railway bridge. In each of the above embodiments, the superstructure of the bridge is taken as an example of the structure, but the present disclosure is not limited thereto. The structure may be deformed by the movement of the moving object.
(156) The embodiments and the modification described above are merely examples, and the present disclosure is not limited thereto. For example, the embodiments and the modification can be combined as appropriate.
(157) The present disclosure includes a configuration substantially the same as the configuration described in the embodiments, for example, a configuration having the same function, method, and result, or a configuration having the same object and effect. The present disclosure includes a configuration obtained by replacing a non-essential portion of the configuration described in the embodiment. In addition, the present disclosure includes a configuration having the same operation effect as the configuration described in the embodiment, or a configuration capable of achieving the same object. The present disclosure includes a configuration obtained by adding a known technique to the configuration described in the embodiment.