Sonar buoy arraying method and device in dynamic environment and storage medium

Abstract

The invention relates to the technical field of sonar detection arraying, in particular to a sonar buoy arraying method and device in a dynamic environment and a storage medium. The sonar buoy arraying method comprises the following steps: calculating a minimum operating distance parameter of sonar buoys according to a selected target area, environment forecast data in a selected time range and an operating threshold value of the sonar buoys; according to the minimum operating distance parameters of the sonar buoys, the arrangement positions of the sonar buoys are set, so that the arranged total operating area covers the target area; and generating a sonar buoy laying path according to the sonar buoy laying position. According to the method, the minimum operating distance of the sonar buoy is calculated, and sonar array arrangement is carried out according to the minimum operating distance, so that the environment adaptation capability of the sonar buoy array is enhanced, and the stable coverage performance of the sonar buoy is remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of sonar detection array, and specifically relates to a method, device and storage medium for sonar buoy array in a dynamic environment. Background Art

[0002] A sonar buoy array consists of multiple sonar buoys, which are deployed at specific positions to form an array for detecting and locating underwater targets. Existing sonar buoy array methods mainly focus on how to improve the coverage range and deployment efficiency through reasonable array design. In related technologies, there are generally three array methods. One is the multi-static sonar buoy array: this method aims at the multi-static centralized detection mode and analyzes the influence of the array pattern factors of the sonar buoy array on the sonar detection area. The second is the sonar buoy array with limited quantity. Since the number of sonar buoys carried by an aircraft is limited, this method needs to analyze the array pattern to maximize the detection area so as to meet the mission requirements. The third is the sonar buoy array for the target movement route. This method aims at the possible navigation paths of the target and analyzes the influence of the deployment area and depth of the sonar buoy array on the target detection probability. Through these array methods, the detection probability and coverage area of the sonar buoy array can be significantly improved to meet the requirements of different application scenarios.

[0003] However, traditional sonar buoy arrays usually adopt a passive working mode, considering influencing factors of the marine environment including terrain, bottom type, sound speed, etc., making the prediction result of the array efficiency more comprehensive. Existing sonar buoy array methods do not consider the dynamic changes of the marine environment, and it is difficult to ensure the original coverage area after the environment changes, resulting in inaccurate detection results. Summary of the Invention

[0004] In related technologies, the sonar buoy array method does not consider the dynamic changes of the marine environment, and it is difficult to ensure the original coverage area after the environment changes, affecting the detection result.

[0005] In a first aspect, an embodiment of this application provides a method for sonar buoy array in a dynamic environment. The sonar buoy array method includes: Calculating the minimum operating distance parameter of the sonar buoy according to the selected target area, the environmental forecast data within the selected time range, and the operating threshold of the sonar buoy; Setting the deployment positions of the sonar buoys according to the minimum operating distance parameter of the sonar buoy so that the overall operating area of the deployment covers the target area; Generating a deployment path of the sonar buoys according to the deployment positions of the sonar buoys.

[0006] In combination with the first aspect, in one embodiment, calculating the minimum operating distance of the sonobuoy based on the selected target area, environmental forecast data within the selected time range, and the operating threshold of the sonobuoy includes: Dividing the selected target area into a plurality of grid areas; Calculating the operating distances of the sonobuoy in different grid areas and azimuths based on the environmental forecast data and the operating threshold of the sonobuoy; Calculating the minimum operating distance parameter of the sonobuoy based on the operating distances of the sonobuoy in different grid areas and azimuths.

[0007] In combination with the first aspect, in one embodiment, calculating the operating distances of the sonobuoy in different grid areas and azimuths based on the environmental forecast data and the operating threshold of the sonobuoy includes: Calculating the propagation loss parameters in different grid areas and azimuths using a ray model; Calculating the operating distances of the sonobuoy in different grid areas and azimuths based on the operating threshold of the sonobuoy and the propagation loss parameters.

[0008] In combination with the first aspect, in one embodiment, setting the deployment positions of the sonobuoys based on the minimum operating distance parameter of the sonobuoy includes: Calculating the minimum operating area of the sonobuoy based on the minimum operating distance parameter of the sonobuoy; Calculating the overall operating area of the sonobuoy array based on the minimum operating area of the sonobuoy, so that the overall operating area completely covers the selected target area.

[0009] In combination with the first aspect, in one embodiment, calculating the overall operating area of the sonobuoy array based on the minimum operating area of the sonobuoy includes: Solving for the minimum value of the number of sonobuoys required to completely cover the target area based on the target area and the minimum operating distance parameter; Calculating the position coordinates of each sonobuoy in the sonobuoy array when the number of sonobuoys is at the minimum value.

[0010] In combination with the first aspect, in one embodiment, solving for the minimum value of the number of sonobuoys required to completely cover the target area based on the target area and the minimum operating distance parameter includes: Solving for the minimum value of the number of sonobuoys that can completely cover the target area based on a differential evolution algorithm.

[0011] In combination with the first aspect, in one embodiment, calculating the deployment path of the sonobuoys based on the deployment positions of the sonobuoys includes: Calculating the shortest deployment path of the sonobuoys based on the deployment positions of the sonobuoys.

[0012] In combination with the first aspect, in one embodiment, generating a sonobuoy deployment path according to the sonobuoy deployment position includes: calculating the shortest deployment path of sonobuoys using the nearest insertion method.

[0013] In a second aspect, an embodiment of the present application provides a sonobuoy arraying device in a dynamic environment. The sonobuoy arraying device includes: An action distance calculation unit, which is used to calculate the minimum action distance parameter of sonobuoys according to the selected target area, environmental forecast data within a selected time range, and the action threshold of sonobuoys; A buoy position allocation unit, which sets the sonobuoy deployment position according to the minimum action distance parameter of sonobuoys, so that the overall action area covered by the deployment covers the target area; A path generation unit, which generates a sonobuoy deployment path according to the sonobuoy deployment position.

[0014] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, characterized in that a sonobuoy arraying program is stored on the computer-readable storage medium. When the sonobuoy arraying program is executed by a processor, the steps of the sonobuoy arraying method described in any one of the above are implemented.

[0015] The beneficial effects brought by the technical solutions provided in the embodiments of the present application include: By calculating the minimum action distance of sonobuoys and arranging sonobuoys based on the minimum action distance, the present application enhances the environmental adaptability of the sonobuoy array and significantly improves the stable coverage performance of sonobuoys. Description of the Drawings

[0016] Figure 1 It is a schematic flowchart of a sonobuoy arraying method in an embodiment of the present application; Figure 2 It is a schematic diagram of the action distance of sonobuoys in an embodiment of the present application; Figure 3 It is a schematic diagram of the sonobuoy deployment position in an embodiment of the present application; Figure 4 It is a schematic plan view of sonobuoy deployment in an embodiment of the present application; Figure 5 It is a path diagram of sonobuoy deployment in an embodiment of the present application; Figure 6 It is a schematic hardware structure diagram of the sonobuoy arraying device involved in the embodiment of the present application. Detailed Embodiments

[0017] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0018] In related technologies, the sonar buoy arraying method does not consider the dynamic changes in the ocean environment, making it difficult to ensure the original coverage area after the environment changes, which affects the detection results.

[0019] In a first aspect, an embodiment of this application provides a sonar buoy arraying method in a dynamic environment. The sonar buoy arraying method includes: Step S1: Calculate the minimum operating distance parameter of the sonar buoy according to the selected target area, the environmental forecast data within the selected time range, and the operating threshold of the sonar buoy.

[0020] The above step S1 includes: Step S1a: Divide the selected target area into multiple grid areas.

[0021] In some specific embodiments, the horizontal spacing of the sound source starting point is set to 5 KM, and the working depth is 10 m, that is, the selected space is divided into a number of areas composed of 5×5 KM 2 square basic blocks. Assuming the area size is , with the unit of KM 2 , then the number of grids is . Among them, , .

[0022] Step S1b: Calculate the operating distance of the sonar buoy in different grid areas and azimuths according to the environmental forecast data and the operating threshold of the sonar buoy.

[0023] In some preferred embodiments, the ray model can be used to calculate the propagation loss parameters in different grid areas and azimuths, and then the operating distance of the sonar buoy in different grid areas and azimuths can be calculated according to the operating threshold of the sonar buoy and the propagation loss parameters.

[0024] Optionally, the normal mode model or the parabolic equation model can be used to calculate the propagation loss parameters.

[0025] It should be noted that the ray model adopted in this application has the advantages of being applicable to various terrain conditions and high calculation efficiency, and its strong adaptability to the dynamic environment is suitable for the sound field calculation in the dynamic ocean environment.

[0026] In a specific embodiment of the present application in combination with the above preferred embodiments, step S1b includes: Obtain ocean environmental forecast data (temperature, salinity) and substrate and terrain data at moments, select the Bellhop ray model to calculate the sound field, set the frequency , the number of azimuths is , and the calculation distance is .

[0027] It should be noted that in the above embodiments, the moment serial number of the ocean environmental forecast data, the longitudinal serial number of the basic grid after regional division, represents the transverse serial number, the azimuth serial number , the horizontal distance , represents the vertical distance, where the horizontal distance represents the distance from the acoustic emission source to the receiving source, and the vertical distance refers to the vertical distance from the emission source to the receiving source.

[0028] Furthermore, in some specific embodiments, when the target area to be detected is selected as a region with a horizontal size of 50×50 KM 2 and a vertical depth of 500 M, and 8 moments of environmental forecast data are obtained, and the number of azimuths for sound field calculation is 8 as an example, the region can be divided into 10×10, a total of 100 basic blocks, where , , , , , .

[0029] It should be noted that the above maximum calculation distance R can be selected according to actual needs.

[0030] Furthermore, according to the pre-selected target depth of , the sonobuoy action threshold , combined with the propagation loss calculation results, as shown in Figure 2 , the sonobuoy action distance in different grids and azimuths is obtained, and the calculation method is as follows:

[0031] Step S1c: Calculate the minimum action distance parameter of the sonobuoy according to the action distance of the sonobuoy in different grid regions and azimuths.

[0032] Specifically, in a dynamic ocean environment, if a selected area needs to be stably covered, the minimum operating distance of sonar buoys needs to be solved. , and the calculation method is as follows:

[0033] It should be noted that the minimum operating distance is as Figure 3 and Figure 4 shown. Figure 3 The lower part in

[0034] is the 3D terrain, and the center of the upper circle is the deployment position of the buoy, and the operating distance is the circular range.

[0035] The above step S2 specifically includes: Step S2a: Calculate the minimum operating area of the sonar buoy according to the minimum operating distance parameter of the sonar buoy.

[0036] Specifically, assume that A buoys need to be deployed, and the coordinates of the a-th buoy are , where , , . Then, the grid number corresponding to each buoy is , that is, corresponding to the minimum operating distance is:

[0037] The corresponding minimum operating area of a sonar buoy is:

[0038] Step S2b: Calculate the overall operating area of the sonar buoy array according to the minimum operating area of the sonar buoy, so that the overall operating area completely covers the selected target area.

[0039] Specifically, the above step S2b includes: Step A: Solve the minimum value of the number of sonar buoys required to completely cover the target area according to the target area and the minimum operating distance parameter.

[0040] Specifically, based on the minimum operating area of the sonar buoy calculated in the above step S2a, for a sonar buoy array composed of A buoys, the overall operating area S can be expressed as:

[0041] In addition, the detected selected target area C is:

[0042] To ensure that the overall effective area of the sonobuoy array completely covers the selected area, there is , and thus determine the overall effective area.

[0043] Furthermore, according to the determined overall effective area, the minimum number of sonobuoys covering the selected area is solved .

[0044] In some preferred embodiments, the minimum number of sonobuoys covering the selected area can be obtained by optimizing and solving using the differential evolution algorithm :

[0045] It can be understood that the differential evolution algorithm has the advantages of simple parameters, strong global search ability, fast convergence speed, high robustness, etc., which can improve the calculation efficiency of the minimum number of sonobuoys.

[0046] Step B: Calculate the position coordinates of each sonobuoy in the sonobuoy array when the number of sonobuoys is the minimum.

[0047] It should be noted that the position coordinates of each sonobuoy can be determined according to the minimum number of sonobuoys obtained in the above step A and the arraying scheme .

[0048] Step S3: Generate the sonobuoy deployment path according to the sonobuoy deployment positions.

[0049] Specifically, it is necessary to calculate the shortest deployment path of the sonobuoys according to the sonobuoy deployment positions.

[0050] It should be noted that the buoy deployment depends on aircraft dropping. Therefore, to improve the aircraft arraying speed, it is necessary to formulate the shortest deployment path.

[0051] In some preferred embodiments, the nearest insertion method can be used to calculate the shortest deployment path of the sonobuoys.

[0052] Combined with the above preferred embodiments, specific embodiments of calculating the shortest deployment path using the nearest insertion method include: Step S3a: Select a starting vertex .

[0053] Step S3b: Among the vertices not yet added to the path, select a vertex that is the closest to a certain vertex in the current path .

[0054] Step S3c: Insert the selected vertex into the best position in the path, such as and , to satisfy the total distance increased after insertion Minimum, i.e.:

[0055] Step S3d: Repeat step S3b and step S3c until all vertices are added to the path, and re - define the sequence numbers of each point in the path in order , where , and obtain the total path length : ; Step S3e: By selecting the set of points on the outermost periphery of the sonar buoy array as the set of starting points, where , , and respectively calculate the total path lengths , where .

[0056] Step S3f: Solve to obtain the path sequence number corresponding to the shortest total path :

[0057] Finally, select the starting point corresponding to the sequence number , and obtain the shortest path calculated based on the nearest - insertion method, which can assist the aircraft to achieve the purpose of deploying sonar buoys fastest along this path. It should be noted that in the face of a complex ocean environment and a large - scale buoy array, the nearest - insertion method can quickly generate an approximate optimal solution and quickly obtain the shortest deployment path.

[0058] Based on the above sonar buoy deployment method, this application provides a specific implementation case, which includes:

[0059] First, select a specific detection time period, select a sea area of 30 * 20 square kilometers, extract ocean environment forecast data, and at the same time use bellhop to calculate the propagation loss, calculate the current buoy action distance according to the buoy action threshold, and the visualization is as shown. Figure 2 shown.

[0060] Then, based on the calculated action distance, calculate the deployment positions of sonar buoys using the differential evolution algorithm. The visualization results of the calculation results are as Figure 3 , Figure 4 (both are minimum action distance diagrams) shown. Using 55 sonar buoys, stable coverage of this area can be achieved under dynamic ocean environment conditions.

[0061] Finally, based on the nearest - insertion method, solve the shortest deployment navigation path under the deployment positions of these buoys, as Figure 5As shown, the path length is 207.04 kilometers, which allows the aircraft to navigate along this path to achieve the rapid deployment of sonobuoy.

[0062] In a second aspect, the present application provides a sonobuoy arraying device in a dynamic ocean environment. The sonobuoy arraying device includes: an action distance calculation unit, a buoy position allocation unit, and a path generation unit; wherein, The action distance calculation unit is used to calculate the minimum action distance parameter of the sonobuoy according to the selected target area, the environmental forecast data within the selected time range, and the action threshold of the sonobuoy; the buoy position allocation unit sets the deployment positions of the sonobuoys according to the minimum action distance parameter of the sonobuoy so that the overall action area covered by the deployment covers the target area; the path generation unit generates a sonobuoy deployment path according to the sonobuoy deployment positions.

[0063] In a third aspect, an embodiment of the present application provides a sonobuoy arraying device. The sonobuoy arraying device can be a device with data processing functions such as a personal computer (PC), a laptop computer, a server, etc.

[0064] Referring to Figure 6 , Figure 6 is a schematic hardware structure diagram of the sonobuoy arraying device involved in the solution of the embodiment of the present application. In the embodiment of the present application, the sonobuoy arraying device may include a processor, a memory, a communication interface, and a communication bus.

[0065] Among them, the communication bus can be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0066] The communication interface includes an input / output (I / O) interface, a physical interface, a logical interface, etc., which are interfaces for realizing the interconnection of internal devices of the sonobuoy arraying device, and interfaces for realizing the interconnection of the sonobuoy arraying device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display screen (Display), a keyboard (Keyboard), etc.

[0067] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical memory, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0068] The processor can be a general-purpose processor, which can call the sonar buoy arraying program stored in the memory and execute the sonar buoy arraying method provided in the embodiments of the present application. For example, the general-purpose processor can be a central processing unit (CPU). Among them, the method executed when the sonar buoy arraying program is called can refer to the various embodiments of the sonar buoy arraying method of the present application, which will not be elaborated here.

[0069] Those skilled in the art can understand that Figure 6 the hardware structure shown in

[0070] In a fourth aspect, the embodiments of the present application further provide a readable storage medium.

[0071] The sonar buoy arraying program is stored on the readable storage medium of the present application. When the sonar buoy arraying program is executed by a processor, the steps of the sonar buoy arraying method as described above are implemented.

[0072] Among them, the method implemented when the sonar buoy arraying program is executed can refer to the various embodiments of the sonar buoy arraying method of the present application, which will not be elaborated here.

[0073] In summary, the present invention improves the traditional mode of deploying according to a fixed operating range to deploying according to the ocean environment, which can effectively increase the operating range and reduce redundant areas. By introducing a dynamic ocean environment change mode, the buoy array has the ability to stably cover a specific area within a certain period of time, enhancing the environmental adaptability of the sonar buoy array and significantly improving the stable coverage performance of the sonar buoy. Taking advantage of the flexibility and strong search ability of the nearest insertion method, the path of buoy arraying is shorter and the deployment time is faster, improving the aircraft arraying speed to meet the requirements of rapid sonar buoy arraying in a dynamic ocean environment.

[0074] It should be noted that the serial numbers of the above embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0075] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions for causing a terminal device to execute the methods described in various embodiments of the present application.

[0076] The terms "comprising" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices. The descriptions of the terms "first", "second", "third", etc. are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit that "first", "second", and "third" are of different types.

[0077] In the description of the embodiments of the present application, terms such as "exemplary", "for example", or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary", "for example", or "for instance" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or designs. Rather, the use of terms such as "exemplary", "for example", or "for instance" is intended to present related concepts in a specific manner.

[0078] In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B can represent A or B; "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0079] In some of the processes described in the embodiments of the present application, there are multiple operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any order of execution. Additionally, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0080] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, are equally included in the patent protection scope of the present application.

Claims

1. A sonar buoy array method in a dynamic environment, characterized in that: The sonar buoy array method comprises: Calculate the minimum operating distance parameter of the sonar buoy according to the selected target area, environmental forecast data of the selected time range and the operating threshold of the sonar buoy; The sonobuoy deployment position is set according to the minimum action range parameter of the sonobuoy so that the overall action area of ​​the deployment covers the target area; Generate a sonar buoy deployment path based on the sonar buoy deployment position.

2. The sonar buoy array method in a dynamic environment as claimed in claim 1, characterized in that: The step of calculating the minimum operating distance of the sonar buoy according to the selected target area, the environmental forecast data of the selected time range and the operating threshold of the sonar buoy comprises: Divide the selected target area into a plurality of grid areas; Calculate the effective distance of sonar buoys in different grid areas and directions according to environmental forecast data and the effective threshold of sonar buoys; The minimum effective range parameters of the sonar buoy are calculated according to the effective range of the sonar buoy in different grid areas and orientations.

3. The sonar buoy array method in a dynamic environment as claimed in claim 2, characterized in that: The method of calculating the effective distance of the sonar buoy in different grid areas and directions according to the environmental forecast data and the effective threshold of the sonar buoy includes: Use the ray model to calculate the propagation loss parameters in different grid areas and orientations; The effective distance of the sonar buoy in different grid areas and orientations is calculated based on the sonar buoy's effective threshold and propagation loss parameters.

4. The sonar buoy array method in a dynamic environment as claimed in claim 1, characterized in that: The step of setting the sonar buoy deployment position according to the minimum action distance parameter of the sonar buoy comprises: Calculate the minimum effective area of ​​the sonar buoy according to the minimum effective range parameter of the sonar buoy; The overall effective area of ​​the sonobuoy array is calculated based on the minimum effective area of ​​the sonobuoy so that the overall effective area completely covers the selected target area.

5. The sonar buoy array method in a dynamic environment as claimed in claim 4, characterized in that: The step of calculating the overall action area of ​​the sonobuoy array according to the minimum action area of ​​the sonobuoy comprises: According to the target area and the minimum effective distance parameters, the minimum number of sonobuoys required to completely cover the target area is solved; Calculate the position coordinates of each sonar buoy in the sonar buoy array when the number of sonar buoys is the minimum.

6. The sonar buoy array method in a dynamic environment as claimed in claim 5, characterized in that: The method of solving the minimum number of sonar buoys required to completely cover the target area based on the target area and the minimum effective distance parameter includes: solving the minimum number of sonar buoys required to completely cover the target area based on a differential evolution algorithm.

7. The sonar buoy array method in a dynamic environment as claimed in claim 1, characterized in that: Calculating the sonar buoy deployment path according to the sonar buoy deployment position, including: calculating the shortest deployment path of the sonar buoy according to the sonar buoy deployment position.

8. The sonar buoy array method in a dynamic environment as claimed in claim 7, characterized in that: The method of calculating the shortest deployment path of the sonar buoy according to the deployment position of the sonar buoy includes: using the nearest insertion method to calculate the shortest deployment path of the sonar buoy.

9. A sonar buoy array device in a dynamic environment, characterized in that: The sonar buoy array device comprises: An action distance calculation unit, which is used to calculate the minimum action distance parameter of the sonar buoy according to the selected target area, the environmental forecast data of the selected time range and the action threshold of the sonar buoy; A buoy position allocation unit sets the sonar buoy deployment position according to the minimum action range parameter of the sonar buoy so that the overall action area of ​​the deployment covers the target area; The path generation unit generates a sonar buoy deployment path according to the sonar buoy deployment position.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a sonar buoy array program, wherein when the sonar buoy array program is executed by the processor, the steps of the sonar buoy array method according to any one of claims 1 to 8 are implemented.

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