Method, device, system, and program for identifying time offset between multiple seismometers

Abstract

To provide a specification method, specification apparatus, specification system and program of a time deviation amount of plural seismometers which can highly accurately calculate a time deviation amount of the plural seismometers and use the calculated time deviation amount for correction of a time deviation.SOLUTION: A specification method of a time deviation amount of plural seismometers 15 placed in a building 10 comprises: an A step of obtaining a displacement of each floor by performing second-order integration of the acceleration waveform measured by seismometers 15 installed at different floors, obtaining an interlayer displacement A based on a measurement value on the basis of the displacement of each floor, obtaining the displacement of each floor by deviating the time of the acceleration waveform of the measurement value, and obtaining an interlayer displacement B based on a time deviation processing waveform on the basis of the displacement of each floor; and a B step of calculating a Fourier spectrum of each of the interlayer displacement A and the plurality of interlayer displacements B, and making a time deviation amount when minimizing an area in a low frequency band of the Fourier spectrum a time deviation amount of the plural seismometers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method, an apparatus, a system, and a program for identifying the amount of time offset between multiple seismometers. [Background technology]

[0002] When installing seismometers such as acceleration sensors on the first and upper floors of a multi-story building and calculating the deformation of the building from the measurement data taken during an earthquake, it is desirable to connect the seismometers on the first and upper floors with a wire and synchronize the time on both seismometers.However, connecting seismometers across floors with a wire has issues such as the complexity of the connection work, the inability to quickly respond to changes in installation location, and wiring limitations.

[0003] On the other hand, by connecting seismometers wirelessly, the disadvantages of wired connections are eliminated, but it then becomes difficult to synchronize the time between the seismometers, which creates another problem: it is not possible to correctly calculate the deformation of each floor of the building at the same time.

[0004] Patent Document 1 proposes an analysis method that can correct for any discrepancy in the time measurements of two seismometers to accurately calculate inter-story displacement. Specifically, the method uses first acceleration data in the X-axis, Y-axis, and Z-axis directions along a time history obtained from a first residential seismometer installed near the first floor or in the foundation below the floor of a wooden building to measure acceleration due to earthquake shaking, and second acceleration data in the X-axis, Y-axis, and Z-axis directions along a time history obtained from a second residential seismometer installed near the first floor ceiling or near the second floor of the wooden building to measure acceleration due to earthquake shaking, and calculates at least the inter-story displacement when the wooden building is shaken using a predetermined analysis processing program. The correlation coefficient is calculated between the first acceleration data in the Z-axis direction from the first residential seismometer and the second acceleration data in the Z-axis direction from the second residential seismometer, and the time history discrepancy between the first acceleration data and the second acceleration data is corrected based on the calculation result, before calculating the inter-story displacement. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-100875 Summary of the Invention [Problem to be solved by the invention]

[0006] The analysis method described in Patent Document 1 calculates a correlation coefficient while gradually shifting the time of vertical acceleration waveforms measured by multiple seismometers, and determines the time shift amount when the correlation coefficient is maximum as the actual time shift amount. Therefore, there is a problem that calculating the correlation coefficient over the entire frequency band results in a decrease in accuracy due to an increase in noise, and this problem is particularly noticeable on the high frequency side.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a method, an identification device, an identification system, and a program for identifying the time offset of multiple seismometers, which can calculate the time offset of multiple seismometers with high accuracy and use the calculated time offset to correct the time offset. [Means for solving the problem]

[0008] In order to achieve the above object, one aspect of the method for specifying the time offset of a plurality of seismometers according to the present invention includes: A method for determining the amount of time offset between multiple seismometers mounted on a building, comprising: Step A: calculating the displacement of each floor by integrating the acceleration waveform measured by each of the seismometers installed on different floors twice, and calculating the inter-story displacement A based on the measured values ​​based on the displacement of each floor, and similarly calculating the displacement of each floor by shifting the time of the acceleration waveform of the measured values, and calculating the inter-story displacement B based on the time-delay processed waveform based on the displacement of each floor; The method is characterized by having a step B in which the Fourier spectrum of each of the inter-story displacements A and the plurality of inter-story displacements B is calculated, the area in the low frequency band of the Fourier spectrum is calculated, and the time deviation amount when the area is minimized is set as the time deviation amount of the plurality of seismometers.

[0009] According to this aspect, the inter-story displacement A is calculated based on the measured values ​​from the displacement of each floor based on the acceleration waveforms measured by the multiple seismometers, and the inter-story displacement B is calculated based on the time-delay-processed waveform from the displacement of each floor when the acceleration waveforms of the measured values ​​are shifted in time. The time delay amount when the area in the low-frequency band of the Fourier spectrum for each inter-story displacement is minimized is used as the time delay amount for the multiple seismometers. Here, "multiple seismometers" refers to, for example, the seismometer on the first floor or foundation floor that measures ground vibration input to the building, and any one of the seismometers on the second or higher floors, when two or three or more seismometers are installed on the first floor (or foundation floor) and two or more floors above, and includes combinations such as seismometers on the first and second floors, seismometers on the first and third floors, and seismometers on the first floor and rooftop (RF) floor.

[0010] Furthermore, the "low frequency band" when calculating the area of ​​the Fourier spectrum refers to a low frequency band in which the building does not resonate, a frequency band in which a multi-story building will behave in translation overall, or a frequency band in which the response is not amplified. By calculating the area of ​​the low frequency band in the Fourier spectrum, the influence of noise (error) can be reduced.

[0011] The inventors have determined that when there is a time offset between multiple seismometers, periodic peaks are present at specific frequencies, whereas when there is no time offset, no periodic peaks are present. When periodic peaks are present, the area of ​​a certain frequency band (low frequency band) in the Fourier spectrum naturally becomes large, while when there are no periodic peaks, the area of ​​the Fourier spectrum becomes small. By gradually shifting the time of the acceleration waveform from the measured value to obtain each inter-story displacement and calculating the area of ​​the Fourier spectrum in the low frequency band for each inter-story displacement, the time offset of the Fourier spectrum with the smallest area can be determined as the time offset between multiple seismometers. For example, by increasing the time offset pitch within the expected time offset to identify the time offset that minimizes the area of ​​the Fourier spectrum, and then further decreasing the time offset pitch near this time offset to identify the time offset that minimizes the area of ​​the Fourier spectrum, more precise determination of the time offset is possible.

[0012] Another aspect of the method for identifying the time offset of a plurality of seismometers according to the present invention is to In the setting of the low frequency band, When the primary natural frequency of the building is set to f0, the low frequency band is set to f0 / 5 or in the range of 0.5 Hz to f0 / 2.

[0013] According to this aspect, by quantitatively setting the upper and lower limits of the low frequency band, it is possible to clarify the calculation region of the area of ​​the Fourier spectrum.

[0014] Here, the basis for setting the upper limit is that the inter-story deformation angle in the elastic region during a normal earthquake is generally set to about 1 / 200, and the inter-story deformation angle in the plastic region during a large-scale earthquake is set to about 1 / 100 to 1 / 75. Based on this, the plastic region is about half the elastic region, and the upper limit for the low frequency band is set to half the primary natural frequency: f0.

[0015] Meanwhile, the basis for setting the lower limit is 0.5 Hz, based on the performance (resolution) of seismometers currently in general use. In other words, since the lower limit can vary depending on the performance of the seismometer, it was decided to set it here based on the performance of the general seismometers currently in use. In addition, the lower limit is set to f0 / 5, which is a value that is approximately 0.5 Hz from the first natural frequency (f0) of an average house.

[0016] Furthermore, one aspect of the device for identifying the time offset of a plurality of seismometers according to the present invention comprises: A device for identifying the amount of time offset between multiple seismometers mounted on a building, comprising: A calculation unit is included, In the calculation unit, The acceleration waveforms measured by the seismometers installed on different floors are integrated twice to determine the displacement of each floor, and the inter-story displacement A is determined based on the measured values ​​based on the displacement of each floor, and the time of the acceleration waveform of the measured values ​​is shifted to similarly determine the displacement of each floor, and the inter-story displacement B is determined based on the time-shifted waveform based on the displacement of each floor, The method is characterized in that the Fourier spectrum of each of the inter-story displacement A and the multiple inter-story displacements B is calculated, the area in the low frequency band of the Fourier spectrum is calculated, and the time deviation amount when the area is minimized is set as the time deviation amount of the multiple seismometers.

[0017] According to this embodiment, the inter-story displacement A is calculated based on the measured values ​​from the displacement of each floor based on the acceleration waveform measured by multiple seismometers, and the inter-story displacement B is calculated based on the time-shifted waveform from the displacement of each floor when the acceleration waveform of the measured values ​​is shifted in time.By using the time shift amount when minimizing the area in the low-frequency band of the Fourier spectrum for each inter-story displacement as the time shift amount of the multiple seismometers, the time shift amount of the multiple seismometers can be calculated with high accuracy.

[0018] Furthermore, one aspect of the system for identifying the time offset of a plurality of seismometers according to the present invention is to a plurality of seismometers provided in the building and the specific device; The apparatus is characterized in that the measurement data measured by the seismometer is received by the specific device.

[0019] According to this aspect, the measurement data measured by the multiple seismometers is transmitted by wireless communication or the like to a specific device located in a related department of the head office or branch office of the house manufacturer or construction company that constructed the building, and the specific device that receives the measurement data quickly identifies the time offset of the target building, corrects the time offset of the multiple seismometers (synchronizes the time) based on the identified time offset, and then calculates the deformation and inter-story deformation angle of the building with high accuracy. Here, the measurement data can be received by the specific device by wireless communication over a network, or by a resident of the target building or a person in charge at the house manufacturer obtaining the measurement data and inputting it into the specific device.

[0020] Furthermore, one aspect of the program according to the present invention is A program that causes a computer constituting an apparatus for identifying the amount of time offset of a plurality of seismometers mounted on a building to execute the following process: The acceleration waveforms measured by the seismometers installed on different floors are integrated twice to determine the displacement of each floor, and the inter-story displacement A is determined based on the measured values ​​based on the displacement of each floor, and the time of the acceleration waveform of the measured values ​​is shifted to similarly determine the displacement of each floor, and the inter-story displacement B is determined based on the time-shifted waveform based on the displacement of each floor, The method is characterized in that the Fourier spectrum of each of the inter-story displacement A and the multiple inter-story displacements B is calculated, the area in the low frequency band of the Fourier spectrum is calculated, and the time deviation amount when the area is minimized is set as the time deviation amount of the multiple seismometers.

[0021] According to this aspect, by causing a computer constituting a time offset specifying device to execute a predetermined process, it is possible to calculate the time offsets of a plurality of seismometers with high accuracy. [Effects of the Invention]

[0022] As can be understood from the above explanation, the method, device, system, and program for identifying the time offset of multiple seismometers of the present invention can identify the time offset of multiple seismometers with high accuracy, and the identified time offset can be used to correct the time offset. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is an overall configuration diagram showing an example of a system for identifying the amount of time offset between multiple seismometers according to an embodiment; [Figure 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a time lag identifying device according to an embodiment. [Figure 3] FIG. 2 is a diagram illustrating an example of a functional configuration of a time lag identifying device according to an embodiment. [Figure 4] 10A and 10B are diagrams showing examples of amplitude graphs of inter-story displacement with and without a time lag. [Figure 5A] FIG. 10 is a diagram showing the relationship between frequency and the Fourier spectrum of the inter-story displacement when the time lag is −0.4 seconds. [Figure 5B] FIG. 10 is a diagram showing the relationship between frequency and the Fourier spectrum of the inter-story displacement when the time lag is −0.2 seconds. [Figure 5C] FIG. 10 is a diagram showing the relationship between frequency and the Fourier spectrum of inter-story displacement in the case where there is no time lag. [Figure 5D] FIG. 10 is a diagram showing the relationship between frequency and the Fourier spectrum of the inter-story displacement when the time difference is +0.1 seconds. [Figure 5E] FIG. 10 is a diagram showing the relationship between frequency and the Fourier spectrum of the inter-story displacement when the time difference is +0.7 seconds. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an example of a method for identifying the time offset of multiple seismometers, an identification device, an identification system, and a program according to an embodiment will be described with reference to the accompanying drawings. Note that in this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[0025] [Method, device, system, and program for identifying the amount of time offset between multiple seismometers according to the embodiment] First, an example of a method, an identification device, an identification system, and a program for identifying the amount of time offset between multiple seismometers according to an embodiment will be described with reference to Figures 1 to 4. Here, Figure 1 is an overall configuration diagram showing an example of a system for identifying the amount of time offset between multiple seismometers.

[0026] The time lag identification system 50 includes a multi-story building 10 (two stories in the illustrated example) equipped with multiple seismometers 15 on each floor, and an identification device 40 according to the embodiment located at the home builder 30 that constructed the building 10, with the seismometers 15 and the identification device 40 being connected via a network 20 so that measurement data is transmitted to the identification device 40. The identification system may also be configured such that the measurement data is obtained by a resident of the building 10 or a person in charge at the home builder, etc., and inputs it into the identification device 40 without going through the network 20, and such a configuration is also included.

[0027] In the illustrated example, a two-story building 10 has seismometers 15A and 15B mounted on the first and second floors, respectively. Earthquake motion E propagating through ground G causes the building 10 to vibrate, and the resulting ground vibrations are measured by seismometer 15A on the first floor, which records the measured measurement data (acceleration data, e.g., acceleration data for the X-, Y-, and Z-axes). Meanwhile, vibrations (response vibrations) of the building are measured by seismometer 15B on the second floor (upper floor), which also records the measured data as acceleration data. Both seismometers 15A and 15B are not time-synchronized via wires, and their respective measurement data are transmitted to identifying device 40 via network 20.

[0028] The network 20 includes a public network such as the Internet, a wireless network such as a mobile phone network, a dedicated network such as a VPN (Virtual Private Network), a LAN (Local Area Network), and the like.

[0029] Next, an example of the hardware configuration of the time lag identifying device 40 will be described with reference to FIG. 2, and an example of the functional configuration of the time lag identifying device 40 will be described with reference to FIG.

[0030] As shown in FIG. 2, the time lag identifying device 40 is configured by an information processing device (computer) such as a personal computer (PC).

[0031] The computer constituting the time lag amount identifying device 40 includes a CPU (Central Processing Unit) 41, a main memory device 42, an auxiliary memory device 43, an input / output IF (interface) 44, and a communication IF 45, which are interconnected by a connection bus 46. The main memory device 42 and the auxiliary memory device 43 are computer-readable recording media. Note that the above components may be provided separately, or some of the components may not be provided.

[0032] The CPU 41 is also called an MPU (Microprocessor) or a processor, and may be a single processor or a multiprocessor. The CPU 41 is a central processing unit that performs overall control of the specific device 40, which is a computer. The CPU 41, for example, deploys a program stored in the auxiliary storage device 43 in an executable form in the working area of ​​the main storage device 42, and controls peripheral devices through the execution of the program, thereby providing functions that meet a predetermined purpose.

[0033] The main memory device 42 stores computer programs executed by the CPU 41, data processed by the CPU 41, etc. The main memory device 42 includes, for example, a flash memory, a RAM (Random Access Memory), and a ROM (Read Only Memory). The auxiliary memory device 43 stores various programs and various data on a readable and writable recording medium, and is also called an external memory device. The auxiliary memory device 43 stores, for example, an OS (Operating System), various programs, various tables, etc. The OS includes, for example, a communication interface program that exchanges data with external devices connected via the communication IF 45. External devices for the specific device 40 include the seismometer 15 and other computers in related departments (various structural calculation computers), etc.

[0034] The auxiliary storage device 43 is used, for example, as a storage area that supplements the main storage device 42, and stores computer programs executed by the CPU 41, data processed by the CPU 41, etc. The auxiliary storage device 43 is a silicon disk including nonvolatile semiconductor memory (flash memory, EPROM (Erasable Programmable ROM)), a hard disk drive (HDD: Hard Disk Drive), a solid state drive, etc. Examples of the auxiliary storage device 43 include drives for removable recording media such as CD drives, DVD drives, and BD drives, and examples of removable recording media include CDs, DVDs, BDs, USB (Universal Serial Bus) memories, and SD (Secure Digital) memory cards.

[0035] The input / output IF 44 is an interface for inputting and outputting data between devices connected to the specific device 40. Input devices such as a keyboard, a touch panel, a mouse, or other pointing device, and a microphone are connected to the input / output IF 44. The specific device 40 receives operation instructions and the like from an operator who operates the input device via the input / output IF 44.

[0036] In addition, output devices such as a display device, a printer, a speaker, etc., such as a liquid crystal display (LCD) panel or an organic electroluminescence (EL) panel, are connected to the input / output IF 44. The identification device 40 displays the Fourier spectra of the inter-story displacements for cases with and without a time lag, the area of ​​each Fourier spectrum in the low frequency band, the time lag between the two seismometers 15A and 15B, etc.

[0037] The communication IF 45 is an interface with the network 20 to which the identifying device 40 is connected. The communication IF 45 transmits measurement data from the seismometer 15 to the identifying device 40 via various networks 20 including the above-mentioned public network such as the Internet.

[0038] 3, the identifying device 40 provides various functions of at least a communication unit 402, a calculation unit 404, and a storage unit 406 by executing a program by a CPU 41. Here, at least a part of the processing functions may be provided by a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), or the like, and similarly, at least a part of the processing functions may be provided by a dedicated LSI (Large Scale Integration) such as an FPGA (Field-Programmable Gate Array), a numerical calculation processor, an image processing processor, or other digital circuits, or the like.

[0039] After an earthquake occurs, the communication unit 402 receives the measurement data transmitted from each seismometer 15 for a certain period of time and stores the data in the storage unit 406 as needed.

[0040] The calculation unit 404 determines the amount of time difference between the two seismometers 15A and 15B based on the measurement data.

[0041] Here, the acceleration waveform (equivalent to the acceleration waveform of the ground) measured by seismometer 15A on the first floor and the absolute displacement at the floor position on the second floor can be expressed by the following formula (X). Note that since there is no phase difference in the low frequency band, the initial phase is not taken into consideration.

[0042]

number

[0043] From equation (X), the inter-story displacement between the first and second floors (inter-story displacement of the first floor) can be expressed by the following equation (Y).

[0044]

number

[0045] The amplitude of the inter-story displacement at this time can be expressed by the following equation (Z).

[0046]

number

[0047] For example, if equation (Z) is expressed as A=1.0 and B=1.5, with frequency f on the horizontal axis and amplitude on the vertical axis, the result will be as shown in Figure 4. In Figure 4, the amplitude when there is no time lag is shown by a solid line, the amplitude when the time lag amount is α=0.1 seconds is shown by a dotted line, the amplitude when the time lag amount is α=0.5 seconds is shown by a dashed-dot line, and the amplitude when the time lag amount is α=1.0 seconds is shown by a dashed-dot line.

[0048] Figure 4 shows that when there is a time lag, there are periodic peaks at a specific frequency, but when there is no time lag, there are no peaks. However, the y-intercept of the straight line (horizontal line) when there is no time lag changes depending on the values ​​of A and B.

[0049] From this, we can see that when there is a time lag between multiple seismometers, the integral value (area) of the amplitude within a certain range does not become a minimum, but becomes a minimum when there is no time lag.

[0050] In addition to the fact that the amplitude area is minimized when there is no time lag as described above, the frequency band defining the calculation range of that area should be set to a range that reflects the vibration characteristics of the building. Therefore, when the primary natural frequency of the building is set to f0, the low frequency band in the range of f0 / 5 or 0.5 Hz to f0 / 2 is set as the frequency band when calculating the area of ​​the Fourier spectrum of the inter-story displacement.

[0051] The area of ​​the Fourier spectrum of the inter-story displacement when there is no time lag and the area of ​​the Fourier spectrum of the inter-story displacement when there is a time lag (for various time lag amounts) are calculated in the above-mentioned low frequency band, the inter-story displacement with the smallest area is identified, and the acceleration waveforms from multiple seismometers that are the source of the identified inter-story displacement can be determined to be waveforms with no time lag.

[0052] If the acceleration waveform of the measured value is the waveform that forms the basis of the Fourier spectrum of the inter-story displacement with the smallest area, the measured value can be identified as having no time lag.On the other hand, if the displacement of each floor is similarly determined by artificially shifting the time from the acceleration waveform of the measured value, and the Fourier spectrum of the inter-story displacement based on the time lag-processed waveform calculated based on the displacement of each floor has the smallest area, it can be determined that the time between the multiple seismometers is shifted by the artificially set time lag amount.

[0053] The calculation unit 404 executes step A, which involves double-integrating the acceleration waveforms measured by the two seismometers 15A and 15B to determine the displacement of each floor (the first and second floors in the illustrated example), determining inter-story displacement A based on the measured values ​​based on the displacement of each floor, and similarly determining the displacement of each floor by shifting the time of the acceleration waveform of the measured values, and determining inter-story displacement B based on the time-delay-processed waveform based on the displacement of each floor. Here, the process of shifting the time of the acceleration waveform of the measured values ​​to determine inter-story displacement B based on the time-delay-processed waveform is performed for each of a plurality of artificially set time delay amounts.

[0054] Next, the Fourier spectrum of each of the inter-story displacements A and B is calculated, the area in the low frequency band of the Fourier spectrum is calculated, and the time lag amount when the area is minimized is set as the time lag amount of the multiple seismometers.

[0055] The series of processes in steps A and B by the calculation unit 404 constitutes the method for identifying the amount of time lag according to the embodiment.

[0056] In the identification device 40, the above processing is performed in the calculation unit 404 by installing a program that causes a computer to execute the following processing. That is, the processing based on this program involves double-integrating the acceleration waveforms measured by the two seismometers 15A and 15B to determine the displacement of each floor, determining the inter-story displacement A based on the measured values ​​based on the displacement of each floor, shifting the time of the acceleration waveforms of the measured values ​​to similarly determine the displacement of each floor, determining the inter-story displacement B based on the time-delay-processed waveform based on the displacement of each floor, calculating the Fourier spectrum of each of the inter-story displacement A and the multiple inter-story displacements B, calculating the area in the low-frequency band of the Fourier spectrum, and determining the time lag when the area is minimized as the time lag of the multiple seismometers.

[0057] According to the illustrated device, system, and method for identifying the time lag of a seismometer, the acceleration waveform or time lag processed waveform of the measured value that minimizes the area in the low frequency band of the Fourier spectrum of the inter-story displacement can be identified as having no time lag, and based on this, it is possible to identify in a relatively short time whether or not there is a time lag in the acceleration waveform of the measured value, and the amount of time lag if there is a time lag.

[0058] Furthermore, since the time offset is determined for the low frequency band, the influence of noise (error) is small, and the time offset can be determined with high accuracy.

[0059] The identification device 40 may further include a structural calculation unit (not shown), which corrects the time difference between the measurement data of the seismometers 15A and 15B based on the identified time difference, and then calculates the deformation of the first and second floors during an earthquake based on both sets of time-synchronized measurement data, thereby calculating the inter-story deformation angle of the building 10. Based on the calculated inter-story deformation angle, the safety level and the degree of damage of the building 10 can be evaluated.

[0060] [Experiments and analysis to verify the validity of the calculation formula for time lag] The inventors conducted experiments and analyses using the above-described identification device 40 and a series of processes using the identification method. In these experiments and analyses, the Fourier spectrum of the story displacement A was calculated based on the actual measured values ​​(acceleration waveforms of the measured values) of two seismometers that ultimately had no time lag, and then the time of the acceleration waveforms of the measured values ​​was artificially shifted in four patterns to create four types of time-lag-processed waveforms, and the Fourier spectrum of the story displacement B was calculated based on each of the time-lag-processed waveforms. After calculating the areas in the low-frequency band of the Fourier spectra of a total of five types of story displacements, the Fourier spectrum that gave the smallest area was identified.

[0061] Here, the time deviations artificially set for the acceleration waveform of the measured values ​​(the set time deviations ultimately become the time deviations themselves) are -0.4 seconds, -0.2 seconds, +0.1 seconds, and +0.7 seconds.

[0062] The low frequency band for calculating the area of ​​the Fourier spectrum was set to the range of 1.0 Hz to less than 4.0 Hz. Figures 5A to 5E show the cases of a time lag of -0.4 seconds, a time lag of -0.2 seconds, no time lag (measured value), a time lag of +0.1 seconds, and a time lag of +0.7 seconds, respectively.

[0063] As a result of calculating the areas A1 to A5 in FIGS. 5A to 5E, it was determined that the area A3 of the Fourier spectrum in FIG. 5C is the smallest.

[0064] Since the Fourier spectrum in FIG. 5C is a Fourier spectrum based on the acceleration waveform of the actual measurement value, it can be determined that the acceleration waveform of the actual measurement value has no time lag.

[0065] It is also possible to set the artificial time offset for the actual measurement value to a smaller interval (for example, -0.01 seconds, +0.01 seconds, etc.), calculate the Fourier spectrum of the inter-story displacement B based on each time offset processed waveform, and identify the Fourier spectrum that gives the smallest area. If, through this process, the area of ​​the Fourier spectrum of the inter-story displacement B based on the time offset processed waveform with the time offset set to +0.01 seconds is smallest, it can be determined that the actual measurement value has a time offset and that the time offset is +0.01 seconds.

[0066] In this way, in the first step, processing is performed by artificially setting a large pitch for the amount of time shift, and the acceleration waveform of the measured value or the time shift processing waveform that forms the basis of the Fourier spectrum of the inter-story displacement that gives the smallest area is identified.In the next step, processing is performed by artificially setting a small pitch for the amount of time shift, thereby improving the accuracy of identifying whether there is a time shift and the amount of time shift.

[0067] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0068] 10: Building (two-story building) 15,15A,15B: Seismograph 20: Network 30: House builder 40: Specific device (specific device for time deviation amount) 50: Specific system (specific system for time deviation) 402: Communications Department 404: Arithmetic section 406: Storage area G: Ground E: Earthquake motion

Claims

1. A method for determining the amount of time offset between multiple seismometers mounted on a building, comprising: Step A: integrating the acceleration waveforms measured by the seismometers installed on different floors twice to determine the displacement of each floor, and determining inter-story displacement A based on the measured values ​​based on the displacement of each floor; and similarly determining the displacement of each floor by shifting the time of the acceleration waveforms of the measured values, and determining inter-story displacement B based on the time-delay processed waveform based on the displacement of each floor; A method for determining the amount of time offset of multiple seismometers, characterized by comprising a step B of calculating the Fourier spectrum of each of the inter-story displacement A and the multiple inter-story displacements B, calculating the area in the low frequency band of the Fourier spectrum, and determining the amount of time offset when the area is minimized as the amount of time offset of the multiple seismometers.

2. In the setting of the low frequency band, The first natural frequency of the building is f ０ When the low frequency band is set to f ０ / 5 or 0.5 Hz to f ０ 2. The method for determining the time offset of a plurality of seismometers according to claim 1, wherein the time offset is set within a range of 1 / 2.

3. A device for identifying the amount of time offset between multiple seismometers mounted on a building, comprising: A calculation unit is included, In the calculation unit, The acceleration waveforms measured by the seismometers installed on different floors are integrated twice to determine the displacement of each floor, and an inter-story displacement A based on the measured values ​​is determined based on the displacement of each floor, and the time of the acceleration waveform of the measured values ​​is shifted to similarly determine the displacement of each floor, and an inter-story displacement B based on the time-shifted waveform is determined based on the displacement of each floor, A device for determining the amount of time offset of multiple seismometers, characterized in that it calculates the Fourier spectrum of each of the inter-story displacement A and the multiple inter-story displacements B, calculates the area in the low frequency band of the Fourier spectrum, and determines the amount of time offset when the area is minimized as the amount of time offset of the multiple seismometers.

4. a plurality of seismometers provided in the building and the identifying device according to claim 3; A system for identifying the amount of time offset between a plurality of seismometers, characterized in that the system is configured so that measurement data measured by the seismometers is received by the identifying device.

5. A program that causes a computer constituting an apparatus for identifying the amount of time offset of a plurality of seismometers mounted on a building to execute the following process: The acceleration waveforms measured by the seismometers installed on different floors are integrated twice to determine the displacement of each floor, and an inter-story displacement A based on the measured values ​​is determined based on the displacement of each floor, and the time of the acceleration waveform of the measured values ​​is shifted to similarly determine the displacement of each floor, and an inter-story displacement B based on the time-shifted waveform is determined based on the displacement of each floor, A program characterized by calculating the Fourier spectrum of each of the inter-story displacement A and the multiple inter-story displacements B, calculating the area in the low frequency band of the Fourier spectrum, and setting the time deviation amount when the area is minimized as the time deviation amount of the multiple seismometers.

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