JP2010078445A - Significant wave height calculator, program, and significant wave height calculating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique conveniently eliminating an influence of abnormal data in calculating an average wave height of significant wave heights, etc. <P>SOLUTION: The significant wave height calculator comprises a significant wave height calculation means calculating a predetermined significant wave height value for wave height values, based on wave height data including wave height values of predetermined waves (steps 33 to 35); an abnormal wave height value detection means detecting a wave height value, larger than a value obtained by multiplying the significant wave height value calculated in the significant wave height calculation means by a predetermined value, as an abnormal wave height value out of the wave height values within the wave height data (steps 34, 36); and a control means calculating again the significant wave height value by the significant wave height calculation means without employing the abnormal wave height value when the abnormal wave height value is detected by the significant wave height calculation means (step 37). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a significant wave height calculation device for calculating a significant wave height or a 1/10 significant wave height based on wave height data including a wave height value of each predetermined wave, a program for causing a computer to function as the device, and the device. The present invention relates to a method for calculating a significant wave height.

  Conventionally, in a data set of wave up-and-down movement or displacement measured in one observation, the measurement period is usually about 512 to 1200 seconds, and the number of samples is 1024 to 4800 depending on the sampling interval. . There may be abnormal data in the displacement data set. As a method for extracting and correcting such abnormal data, a spike cut method and a differential method are known.

  FIG. 7 shows how abnormal data is corrected by the spike cut method. An example of a displacement data set is shown in the graph in the figure. The horizontal axis of the graph is time, the vertical axis is displacement, and each displacement data (sampling data) is indicated by a black circle “●”. According to the spike cut method, as shown in the figure, for example, the sampling data B exists in the displacement range 71 from the minimum value 000H to 00FH, or in the range 72 from FF0H to the maximum value FFFH. If the sampling data A is not in the range 71 or 72, the sampling data B is regarded as abnormal data, and the displacement amount of the sampling data B is corrected by being replaced by the displacement amount of the sampling data A. The sampling data D existing in the range 72 is regarded as normal data because the sampling data C one sampling before is also present in the range 72.

  FIG. 8 shows how abnormal data is corrected by a differential method. An example of a displacement data set is shown in the graph of FIG. The horizontal axis of the graph is time, the vertical axis is displacement, and each displacement data (sampling data) is indicated by a black circle “●”. According to the differentiation method, the displacement data set shown in FIG. The sampling data whose differential value is equal to or greater than a predetermined threshold value is regarded as abnormal data, and the displacement amount is replaced with the displacement amount of the sampling data before one sampling. In the case of (a) in the figure, the result of differentiation once becomes as shown in (b) in the figure, and since the first-order differential values at the times t4 and t3 are equal to or greater than the threshold value, the sampling data E at the time t4 is abnormal data. It is assumed that there is a displacement, and the displacement is corrected by replacing it with the displacement of the sampling data F at time t3.

  Conventionally, when calculating the significant wave height and the significant wave period, each wave is defined by the zero-up cross method or the like based on the displacement data set in which the abnormal data is corrected in this way. A period is obtained. Then, based on the obtained wave height and wave period data, the significant wave height and the significant wave period are calculated.

  In addition, when measuring the wave height using a buoy, a technique is known in which the influence of buoy fluctuation on a measured value is electrically suppressed (see, for example, Patent Document 1). According to this technique, the effect of buoy swaying on the measured value is reduced. However, as a countermeasure against abnormal data generated due to sudden fluctuations, electrical noise, or the like, the spike cut method or the like is used.

JP 2007-171146 A

  However, according to the spike cut method, the displacement data can be corrected only when the change pattern of the displacement amount is a pattern as shown in FIG.

  In addition, according to the differential method, a data area having the same capacity as the displacement data set is required to store the result of the first-order differentiation of the displacement data set. That is, a memory having a large capacity is required. Moreover, the subtraction process for the number of samplings is required, and the calculation time for that is required. In this subtraction process, for each time tn (n = 0, 1, 2,...), The displacement amount at time t (n−1) is subtracted from the displacement amount at time tn to obtain a primary differential value. .

  An object of the present invention is to provide a technique for simply eliminating the influence of abnormal data when calculating a significant wave height in view of the problems of the prior art.

  In order to achieve this object, the significant wave height calculating apparatus according to the first invention is based on wave height data including the wave height value of each predetermined wave, and is significant for calculating a predetermined wave height value for the wave height value. A wave height value greater than a value obtained by multiplying a significant wave height value calculated by the significant wave height calculation means by a predetermined value among wave height values in the wave height calculation means and an abnormal wave height value If the abnormal peak value is detected by the abnormal peak value detecting means and the abnormal peak value detecting means, the significant peak value by the significant peak height calculating means is used without using the abnormal peak value. And control means for redoing the calculation.

  The significant wave height calculation device according to a second invention is the first invention, wherein the wave height data is acquired based on displacement data obtained by sampling a wavefront displacement at a predetermined point at predetermined intervals for a predetermined period. Wave height data acquisition means, and abnormal displacement amount correction means for correcting an abnormal displacement amount included in a displacement data portion corresponding to a wave related to an abnormal wave height value detected by the abnormal wave detection means of the displacement data; , Obtaining the wave height value of the displacement data portion corrected by the abnormal displacement amount correcting means, and replacing the abnormal wave height value in the wave height data with the wave height value to correct the abnormal wave height value A peak value correcting unit, and the control unit uses the peak data obtained by correcting the abnormal peak value by the abnormal peak value correcting unit. And performing again the significant wave height value calculated without using the value.

  The significant wave height calculation apparatus according to a third invention is characterized in that, in the second invention, the abnormal displacement amount correcting means corrects the abnormal displacement amount by a differential method.

  The significant wave height calculation device according to a fourth aspect of the present invention is the first to third inventions, wherein the wave height value to be detected by the abnormal wave height detection means is significant by the significant wave height calculation means in the wave height data. Only the maximum peak value among the peak values used for the calculation of the peak value is characterized.

  In the significant wave height calculation device according to a fifth aspect of the present invention, in the first to fourth aspects of the invention, the control means re-executes the significant wave height value calculation by the significant wave height calculation means, and the abnormal wave height value detection means performs an abnormality. It is repeated until the peak value is no longer detected, and the finally obtained significant peak value is output as a calculation result.

  The significant wave height calculating apparatus according to a sixth aspect of the present invention is the first to fifth aspects, wherein the wave height data includes a value of a wave period of each wave, and the significant wave height calculating apparatus is finally obtained. It has a means for calculating a predetermined significant wave period value for the wave period based on the value of the wave period corresponding to each wave value related to the calculation of the significant wave peak value.

  A program according to a seventh invention causes a computer to function as each means in the significant wave height calculation device according to any one of the first to sixth inventions.

  A significant wave height calculating method according to an eighth invention is based on wave height data including a wave height value of each predetermined wave, a significant wave height calculating step for calculating a predetermined wave height value for the wave value, and the wave height Abnormal peak value detection for detecting, as an abnormal peak value, a peak value larger than a value obtained by multiplying a significant peak value calculated in the significant peak value calculation step by a predetermined value among the peak values in the data And when the abnormal peak value is detected by the abnormal peak value detecting step, the control step of redoing the calculation of the significant peak value by the significant pulse height calculation step without using the abnormal peak value; and It is characterized by comprising.

  According to the present invention, the influence of an abnormal peak value can be easily eliminated when calculating a significant wave height.

  FIG. 1 is a block diagram showing a significant wave high wave period calculation apparatus according to an embodiment of the present invention. This device calculates a significant wave height and a significant wave period based on a displacement data set obtained by sampling a wave displacement observed as a fluctuation in water level at a predetermined point at a predetermined interval for a predetermined period. Is. In the figure, 1 is an input unit that receives an input of a displacement data set, 2 is a processing unit that calculates a significant wave height and a significant wave period based on the displacement data set received by the input unit 1, and 3 is a processing unit 2 It is an output part which outputs the calculated significant wave height and a significant wave period. The input unit 1 includes a serial port for receiving a displacement data set as serial data. The processing unit 2 includes a CPU, a memory, a program built in the memory, and the like. The output unit 3 includes an external storage device, a display device, a printer, and the like to which the calculation result of the processing unit 2 is output.

  FIG. 2 shows an example of a waveform indicated by the displacement data set. The horizontal axis is time, the vertical axis is displacement, H1 to H4 are the wave heights of each wave, and T1 to T4 are the period of each wave. Each wave is defined by the zero up cross method. 21 in the figure is an arrow indicating a zero-up cross point.

  FIG. 3 is a flowchart showing processing for calculating the significant wave height and the significant wave period in the processing unit 2. When the processing is started, first, in step 31, the processing unit 2 extracts each wave by the zero up cross method based on the displacement data set Heni having the number of data of 2048. That is, the average value of the displacement amount in the displacement data set is obtained, and using this as a reference (zero), the zero up cross point of each wave as shown in FIG. 2 is obtained.

  Next, in step 32, the wave height and wave period of each extracted wave are obtained. The wave height is obtained as the difference between the maximum displacement and the minimum displacement between the zero-up cross points defining the wave. The wave period is obtained as the time difference between the zero up cross points. Further, the number of extracted waves Hasu is obtained.

  Next, in step 33, the wave heights and wave periods of the obtained waves are rearranged in order from the highest wave height, and stored in an array Wave as shown in FIG. 4 to construct wave height wave period data. That is, the wave height wave period data Wave is composed of 1 to Hasu records, and each record has fields of wave height H and wave period T. Of the records used to calculate the significant wave height and the significant wave period, the wave height and wave period in the record with the highest wave height (the first record in the initial state) are referred to as “maximum wave height” and “maximum It is called “wave period”.

  Next, in step 34, the value obtained by dividing the wave number Hasu by 3 is stored in Hasu3 (Hasu3 = Hasu / 3), and 1 is stored in the pointer Co (Co = 1). The pointer Co is used to indicate a record related to the maximum wave height in the wave. In addition, a threshold value k for the ratio between the maximum wave height and the significant wave height is set. The threshold value k is a threshold value for determining whether or not the maximum wave height is abnormal. That is, when the ratio exceeds the threshold value k, the maximum wave height is regarded as abnormal. For example, 2.5 corresponds to the threshold value k. Sea waves have a strong random nature, and the displacement data obtained by observing the waves requires statistical treatment, but there is a fixed relationship between the maximum wave height and the significant wave height, The wave height is about 1.4 to 2 times the significant wave height. Therefore, when the maximum wave height is 2.5 times or more the significant wave height, the maximum wave height can be regarded as abnormal.

  Next, in step 35, the average of the wave height and the wave period for the data from the Coth to the Hasu3rd, counting from the larger wave height among the records in the wave height wave period data Wave, is obtained, and each provisional significance is obtained. The wave height is H1 / 3 and the significant wave period T1 / 3.

  Next, in step 36, the ratio of the wave height in the Co-th record in the wave height wave period data Wave, that is, the maximum wave height to the obtained significant wave height H1 / 3 exceeds the threshold value k (Wave (H, Co )> K * H1 / 3). If it is determined that it exceeds, the process proceeds to step 37. That is, the maximum wave height Wave (H, Co) in the Coth record is regarded as abnormal, and Co is incremented and Hasu3 is decremented in order to exclude the Coth record from the calculation target in Step 35 again. Then, the process returns to step 35. Returning to step 35, the significant wave height H1 / 3 and the significant wave period T1 / 3 are calculated using the wave height and wave period in the Co-th record after increment as the new maximum wave height and maximum wave period, and the maximum wave height is calculated. It is determined whether it is abnormal.

  If it is determined in step 36 that “Wave (H, Co)> k * H1 / 3” is not satisfied, the provisional significant wave height H1 / 3 and the provisional significant wave period T1 / 3 finally obtained are determined. Then, the output is outputted as the formal significant wave height and the significant wave period, respectively, and the processing of FIG.

  According to this embodiment, using only the wave height wave period data Wave used in the normal significant wave height and significant wave period calculation sequence (steps 31 to 35), while eliminating the record related to the abnormal wave height, The significant wave height and the significant wave period can be calculated. In other words, it is possible to easily exclude the record relating to the abnormal wave height and to improve the calculation accuracy of the wave height and wave period of the significant wave without the need to additionally create a special abnormal wave height detection data set. Therefore, there is no need for a memory area for the abnormal wave height detection data set, a calculation routine using the abnormal wave height detection data set is unnecessary, and there is no need to debug the calculation routine. Further, the calculation can be performed by a CPU having a small memory capacity. In addition, the calculation time can be shortened.

  FIG. 5 is a flowchart showing a process for calculating a significant wave height and a significant wave period in a significant wave high wave period calculation device according to another embodiment of the present invention. As a configuration diagram of this apparatus, FIG. 1 is applied as it is. The process of FIG. 5 corresponds to the process in which step 37 in the process of FIG. Therefore, the processing contents of steps 31 to 36 and 38 in FIG. 5 are the same as those of steps 31 to 36 and 38 in FIG. However, both data are matched so that the data in the displacement data set Heni corresponding to each record in the wave height wave data Wave can be accessed. For example, during the processing of steps 31 to 33, a pointer indicating the data in the corresponding displacement data set Heni is set for each record in the wave height wave data Wave.

  In the process of FIG. 3, when it is determined that the maximum wave height is abnormal, the significant wave height H1 / 3 and the significant wave period T1 / 3 are calculated again by excluding the record related to the maximum wave height (step 35). ), It is determined whether or not the new maximum wave height is abnormal (step 36). However, in the processing of FIG. 5, when it is determined that the maximum wave height is abnormal, a record related to the maximum wave height is stored. The wave height of the record is corrected without being excluded. In this correction, an abnormal displacement is corrected by applying a differential method only to the displacement data set Heni portion corresponding to the record related to the maximum wave height, and the wave height is obtained based on the corrected displacement data set Heni portion. This is done by rewriting the maximum wave height according to the wave height.

  FIG. 6 shows how the displacement data is corrected by applying the differential method only to the displacement data set Heni. FIG. 4A shows an example of a waveform indicated by a displacement data set similar to FIG. In this displacement data set, the wave having the wave height H3 and the wave period T3 relates to the maximum wave height. When it is determined that the maximum wave height is abnormal, the principle of the differential method shown in FIG. As shown in (b), the abnormal displacement in the wave is corrected. Based on the corrected displacement data, a new wave height Hn for the wave is obtained, and the wave height in the corresponding record in the wave height wave period data is rewritten to Hn.

  That is, when the processing of FIG. 5 is started, the processing unit 2 performs the same processing as Steps 1 to 36 of FIG. 3 and determines that “Wave (H, Co)> k * H1 / 3” is established in Step 36. If so, in step 51, the abnormal displacement in the portion of the displacement data set Heni of the wave corresponding to the maximum wave height is corrected by the differential method (FIG. 8). Then, the maximum wave height is corrected based on the corrected displacement data set Heni portion. That is, a new wave height Hn of the wave is obtained based on the displacement data set Heni, and the wave height of the wave record in the wave height wave period data Wave is rewritten to the wave height Hn. Further, the records in the wave height wave period data Wave are rearranged in the order of the wave height. The first record after the rearrangement has a new maximum wave height. Thereafter, the process returns to step 35, and the significant wave height and the significant wave period are calculated again. If it is determined in step 36 that “Wave (H, Co)> k * H1 / 3” does not hold, the provisional significant wave height finally obtained in step 35 is the same as in the case of the process of FIG. H1 / 3 and provisional significant wave period T1 / 3 are output in step 38 as the formal significant wave height and significant wave period, respectively.

  According to the present embodiment, the differential value is obtained for the entire displacement data set as in the prior art, and the abnormal displacement is corrected by comparing the abnormal displacement and then calculating the significant wave height and the significant wave period. The displacement correction need only be performed for the displacement data set portion corresponding to the maximum wave height determined to be abnormal, and thus the memory capacity and calculation time used can be reduced. That is, in the example of FIG. 6, according to the conventional method, it is necessary to obtain a differential value for the displacement of four waves having a period of T1 to T4. However, according to the present embodiment, one wave having a period of T3 is obtained. It is only necessary to obtain a differential value only for the displacement.

  Note that the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, in the above description, whether or not there is an abnormality in step 36 is determined only for the maximum wave height in the record used for calculating the significant wave height and the significant wave period in step 35. If there are other wave heights that are larger than the value obtained by multiplying the significant wave height by k (step 36), not only the maximum wave height but also the significant wave height and significant wave are recorded again. Excluded in the calculation of the period (step 37), or after correcting and rearranging (step 51), the calculation of the significant wave height and the significant wave period may be performed again (step 35).

It is a block diagram which shows the significant wave high wave period calculation apparatus which concerns on one Embodiment of this invention. An example of the waveform which the displacement data set in the apparatus of FIG. 1 shows is shown. It is a flowchart which shows the process which calculates the significant wave height and the significant wave period in the process part of the apparatus of FIG. It is a figure which shows the crest period data Wave in the apparatus of FIG. It is a flowchart which shows the process which calculates the significant wave height and the significant wave period in the significant wave high wave period calculation apparatus which concerns on another embodiment of this invention. It is a figure which shows a mode that a displacement method is applied only to a part of displacement data set Heni in the apparatus of FIG. 1, and displacement data is correct | amended. It is a figure which shows a mode that the abnormal data in a displacement data set is correct | amended by the spike cut method. It is a figure which shows a mode that the abnormal data in a displacement data set is correct | amended by a differentiation method.

Explanation of symbols

  1: input unit, 2: processing unit, 3: output unit, 21: arrow, 71, 72: displacement range, A to F: displacement data.

Claims (8)

Significant wave height calculating means for calculating a predetermined significant wave height value for the wave height value based on the wave height data including the wave height value of each predetermined wave;
An abnormal wave for detecting, as an abnormal wave value, a wave value larger than a value obtained by multiplying a significant wave height value calculated by the significant wave height calculating means by a predetermined value among the wave value values in the wave height data. High value detection means;
When the abnormal peak value is detected by the abnormal peak value detecting means, the control means re-calculates the significant peak value by the significant pulse height calculation means without using the abnormal peak value. A significant wave height calculating device. Wave height data acquisition means for acquiring the wave height data based on displacement data obtained by sampling the displacement of the wavefront at a predetermined point at predetermined intervals for a predetermined period;
Among the displacement data, an abnormal displacement amount correction unit that corrects an abnormal displacement amount included in a displacement data portion corresponding to a wave related to the abnormal peak value detected by the abnormal wave detection unit;
An abnormal wave that corrects the abnormal peak value by acquiring the peak value of the wave of the displacement data portion that has been corrected by the abnormal displacement amount correcting unit and replacing the abnormal peak value in the peak data with the peak value High value correction means,
The control means re-calculates the significant peak value calculation without using the abnormal peak value by using the peak data in which the abnormal peak value is corrected by the abnormal peak value correcting means. The significant wave height calculation device according to 1.   The significant wave height calculating apparatus according to claim 2, wherein the abnormal displacement amount correcting means corrects the abnormal displacement amount by a differential method.   The wave height value to be detected by the abnormal wave height detecting means is only the maximum wave height value among the wave height values used for calculating the significant wave height value by the significant wave height calculating means in the wave height data. The significant wave height calculation apparatus according to any one of claims 1 to 3.   The control means repeats the significant wave height value calculation by the significant wave height calculation means until the abnormal wave height value is not detected by the abnormal wave height detection means, and finally the significant wave obtained The significant wave height calculation device according to claim 1, wherein the high value is output as a calculation result. The wave height data includes the value of the wave period of each wave,
The significant wave height calculation device further calculates a predetermined significant wave period value for the wave period based on the value of the wave period corresponding to each wave value related to the calculation of the significant wave peak value finally obtained. The significant wave height calculation apparatus according to claim 1, further comprising:   A program for causing a computer to function as each means in the significant wave height calculation apparatus according to claim 1. Based on the wave height data including the wave height value of each predetermined wave, a significant wave height calculating step for calculating a predetermined significant wave height value for the wave height value;
An abnormal wave for detecting, as an abnormal wave height, a wave height value larger than a value obtained by multiplying a significant wave height value calculated by the significant wave height calculating step by a predetermined value among the wave height values in the wave height data. High value detection process;
A control step for re-calculating the significant wave height value by the significant wave height calculation step without using the abnormal wave height value when the abnormal wave height value is detected by the abnormal wave height value detecting step. A significant wave height calculation method.

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