GIS fault signal positioning method and system based on energy search

Abstract

The invention discloses a GIS fault signal positioning method and system based on energy search. The method comprises the steps that fault signals synchronously collected by n sensors installed in GIS equipment are acquired; traversing the fault signal corresponding to each sensor, and calculating a comprehensive difference value between the traversed fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors; for the traversed fault signal corresponding to the current sensor, determining a fault signal with the amplitude closest to that of the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors; determining a fault occurrence range detected by the current sensor according to the comprehensive difference value corresponding to the current sensor and the nearest fault signal; taking an overlapping region of the fault occurrence ranges corresponding to all the sensors as a fault occurrence position; according to the invention, the GIS fault positioning accuracy can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment fault location, and in particular to a GIS fault signal location method and system based on energy search. Background Art

[0002] High-voltage gas-insulated switchgear (GIS) is a metal-enclosed switchgear insulated by gas. It has a complex structure and usually includes conductive parts, insulating parts, gas isolation chambers, etc. The fault signal location method of GIS equipment usually utilizes a variety of monitoring technologies, such as ultrasonic monitoring, infrared thermal imaging monitoring, current and voltage monitoring, etc. Among them, infrared thermal imaging monitoring uses infrared cameras to capture infrared radiation on the surface of objects and detects local high-temperature faults in GIS equipment by analyzing infrared images; current and voltage monitoring equipment includes sensors, data collectors, and monitoring systems. Sensors are used to monitor current and voltage signals. The data collector converts the signals into digital signals and transmits them to the monitoring system. The monitoring system analyzes and processes the signals.

[0003] In the related art, a precise positioning method based on GIS partial discharge is proposed in the patent application document with publication number CN107219501A. In this scheme, after obtaining the partial discharge, each sensor synchronously obtains the arrival time of the electromagnetic wave, and then introduces the Euclidean measure distance matrix into the ranging result obtained by the extended time difference positioning method to obtain the preliminary partial discharge position; this scheme mainly determines the position of the fault signal by time difference positioning. In practice, the fault signal may be inaccurately positioned because the discharge time is too short and the time accuracy of the sensor signal acceptance time difference is insufficient. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to accurately locate GIS fault signals.

[0005] The present invention solves the above technical problems by the following technical means:

[0006] The present invention proposes a GIS fault signal location method based on energy search, the method comprising:

[0007] Obtain fault signals synchronously collected by n sensors installed in GIS equipment;

[0008] Traverse the fault signal corresponding to each sensor, and calculate the comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors;

[0009] For the fault signal corresponding to the current sensor traversed, determine the fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors;

[0010] Determine the fault range detected by the current sensor based on the comprehensive difference corresponding to the current sensor and the most recently received fault signal;

[0011] The overlapping area of ​​the fault occurrence ranges corresponding to all sensors is taken as the fault occurrence location.

[0012] Furthermore, the calculation is performed to obtain a comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors, and the formula is expressed as follows:

[0013]

[0014] Where E(x) is the basic energy function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the other sensors, exp is the exponential function, log is the logarithmic function, d(x,x (i) ) represents the energy difference function.

[0015] Furthermore, for the fault signal corresponding to the current sensor traversed, a fault signal with an amplitude closest to the fault signal corresponding to the current sensor is determined from the fault signals corresponding to the remaining sensors, and the formula is expressed as:

[0016]

[0017] In the formula, g(x) is the energy search function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the remaining sensors, d(x,x (i) ) represents the energy difference function.

[0018] Furthermore, the formula of the energy difference function is expressed as:

[0019] d(x,x (i) )=||xx (i) || 2

[0020] In the formula, |||| 2 represents the L2 norm.

[0021] Further, the determining of the fault occurrence range detected by the current sensor according to the comprehensive difference corresponding to the current sensor and the most recently received fault signal includes:

[0022] According to the comprehensive difference corresponding to the current sensor and the most recent fault signal, determine the straight-line distance Z between the fault location and the current sensor location t , the formula is:

[0023]

[0024] Where E(x) is the basic energy function, g(x) is the energy search function, and πe is a natural number;

[0025] The fault occurrence range corresponding to each sensor is determined using the straight-line distance corresponding to the sensor as the radius.

[0026] Furthermore, when the number of sensors n is 10, the straight-line distance between the fault location and the current sensor location is determined as:

[0027]

[0028] Where x is the fault signal detected by the current sensor.

[0029] Furthermore, before acquiring the fault signals synchronously collected by n sensors installed in the GIS device, the method further includes:

[0030] Carry out 0-1 planning of the internal structure of GIS equipment and determine the installation locations of sensors for global monitoring.

[0031] In addition, the present invention also proposes a GIS fault signal location system based on energy search, the system comprising:

[0032] The signal acquisition module is used to obtain the fault signals synchronously collected by n sensors installed in the GIS equipment;

[0033] A comprehensive difference calculation module is used to traverse the fault signal corresponding to each sensor and calculate the comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors;

[0034] An amplitude close determination module is used to determine, for the fault signal corresponding to the current sensor that has been traversed, a fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors;

[0035] A fault range determination module is used to determine the fault range detected by the current sensor based on the comprehensive difference corresponding to the current sensor and the most recently received fault signal;

[0036] The fault location determination module is used to take the overlapping area of ​​the fault occurrence ranges corresponding to all sensors as the fault occurrence location.

[0037] In addition, the present invention also proposes a GIS fault signal locating device, which includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the GIS fault signal locating method based on energy search as described above.

[0038] In addition, the present invention also proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned GIS fault signal locating method based on energy search is implemented.

[0039] The advantages of the present invention are:

[0040] (1) The present invention calculates the relevant energy functions of each sensor by using an energy search method. For each sensor, the comprehensive difference between the sensor and the detection signals of the remaining sensors is calculated, and the fault signal closest to the current sensor signal amplitude is found from the detection signals of the remaining sensors. Then, the fault range of the current sensor is determined based on the comprehensive difference and the most recent fault signal. Finally, the common set of fault ranges corresponding to all sensors is used as the final fault location. Since the electromagnetic wave energy intensities received by different sensors are different, the fault signal position is located by calculating the different intensities of the signals received by the sensors. The accuracy of the sensor is not so high, which improves the accuracy of fault location. The method proposed by the present invention first adopts an optimization scheme to obtain a sensor layout scheme, and then a positioning scheme based on energy search is used. Compared with the traditional time difference method for location, the sensor accuracy requirement is lower and the calculation amount is less, which greatly simplifies the fault location process and solves the problem of large calculation amount and inaccurate positioning of traditional GIS fault location.

[0041] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of a GIS fault signal location method based on energy search proposed in one embodiment of the present invention;

[0043] Figure 2 is a schematic diagram of the superposition effect of the fault occurrence ranges corresponding to each sensor in one embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of a section discharge in one embodiment of the present invention;

[0045] Figure 4 It is a structural schematic diagram of a GIS fault signal locating system based on energy search proposed in one embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, the first embodiment of the present invention proposes a GIS fault signal location method based on energy search, and the method includes the following steps:

[0048] S10, obtaining fault signals synchronously collected by n sensors installed in the GIS equipment;

[0049] It should be noted that, in this embodiment, sensors are installed in advance at various positions of the GIS equipment to collect partial discharge signals generated by various partial discharge sources in the GIS equipment.

[0050] S20, traversing the fault signal corresponding to each sensor, and calculating the comprehensive difference between the fault signal corresponding to the current sensor traversed and the fault signals corresponding to the remaining sensors;

[0051] S30, for the fault signal corresponding to the current sensor that has been traversed, determine a fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors;

[0052] S40, determining the fault occurrence range detected by the current sensor according to the comprehensive difference corresponding to the current sensor and the most recently received fault signal;

[0053] S50: taking the overlapping area of ​​the fault occurrence ranges corresponding to all sensors as the fault occurrence location.

[0054] For each sensor, this embodiment calculates the comprehensive difference between the sensor and the detection signals of the remaining sensors, and searches for a fault signal whose amplitude is closest to the current sensor signal from the detection signals of the remaining sensors. Then, the fault range of the current sensor is determined based on the comprehensive difference and the most recent fault signal. Finally, the common set of fault ranges corresponding to all sensors is used as the final fault location, thereby improving the accuracy of fault location.

[0055] As a further preferred technical solution, in step S20, the comprehensive difference between the fault signal corresponding to the current sensor traversed and the fault signals corresponding to the remaining sensors is calculated, and the formula is expressed as:

[0056]

[0057] Where E(x) is the basic energy function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the other sensors, exp is the exponential function, log is the logarithmic function, d(x,x (i) ) represents the energy difference function.

[0058] It should be noted that this embodiment calculates the comprehensive difference by utilizing the basic energy function. By substituting the comprehensive difference into the energy search radius formula, the energy search radius formula describes the energy ranking relationship of different sensors by calculating the point closest to the energy of different sensors, thereby determining a fault point radius.

[0059] As a further preferred technical solution, in step S30, for the fault signal corresponding to the current sensor traversed, a fault signal with an amplitude closest to the fault signal corresponding to the current sensor is determined from the fault signals corresponding to the remaining sensors, and the formula is expressed as:

[0060]

[0061] In the formula, g(x) is the energy search function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the remaining sensors, d(x,x (i) ) represents the energy difference function.

[0062] Furthermore, the formula of the energy difference function is expressed as:

[0063] d(x,x (i) )=||xx (i) || 2

[0064] In the formula, |||| 2 represents the L2 norm.

[0065] In this embodiment, the energy difference between the two sensors is calculated by using an energy difference function.

[0066] It should be noted that, because different sensors receive different signal strengths at the fault point, the sensor with the closest amplitude is found by sorting the energy intensities.

[0067] As a further preferred technical solution, the step S40: determining the fault occurrence range detected by the current sensor according to the comprehensive difference corresponding to the current sensor and the most recently received fault signal, comprises the following steps:

[0068] S41, determine the straight-line distance Z between the fault location and the current sensor location based on the comprehensive difference corresponding to the current sensor and the most recently received fault signal t , the energy search radius formula is as follows:

[0069]

[0070] Among them, g(x) is the energy search function, n is the number of sensors, πe is the natural parameter, and E(x) is the basic energy function.

[0071] It should be noted that in practical applications, such complexity may make the inequality more difficult to interpret and apply, especially in practical sensor signal analysis and fault detection. This embodiment further simplifies it as follows:

[0072]

[0073] Where E(x) is the basic energy function, g(x) is the energy search function, and πe is a natural number;

[0074] Furthermore, when n is large enough, such as 10, a more accurate straight-line distance can be obtained:

[0075]

[0076] Where x is the fault signal detected by the current sensor.

[0077] S42, determining the fault occurrence range corresponding to each sensor by taking the straight-line distance corresponding to the sensor as the radius.

[0078] It should be noted that if Figure 2 As shown, in this embodiment, the fault occurrence range determined by the straight-line distance corresponding to each sensor as the radius is superimposed, and the common intersection, i.e. Figure 2 The shaded part in the figure is taken as the final fault location.

[0079] In this embodiment, g(x) and E(x) are both calculated based on the difference between sensor signals, which helps to accurately identify and quantify signal changes, and provides a possible range of fault locations through inequalities instead of a single estimated value, which helps to improve the accuracy and efficiency of fault detection. In the formula, n represents the number of sensors, which shows that this method can adapt to sensor networks of different sizes and configurations.

[0080] As a further preferred technical solution, before the step S50: obtaining the fault signals synchronously collected by n sensors installed in the GIS device, the method further includes the following steps:

[0081] Carry out 0-1 planning of the internal structure of GIS equipment and determine the installation locations of sensors for global monitoring.

[0082] It should be noted that this embodiment uses a 0-1 planning model to optimize the sensor layout scheme, which can achieve global monitoring of signal generation of GIS equipment.

[0083] Specifically, the specific process of optimizing the sensor layout scheme using the 0-1 programming model in this embodiment includes:

[0084] like Figure 3 As shown in the figure, assuming that the path of the electromagnetic wave generated by the discharge point of any segment to reach the arranged sensor has at least one path passing through the beginning of the segment and one path passing through the end of the segment, then this segment is discharge-measurable. Then, x k As a flag for whether the node has installed the sensor:

[0085]

[0086] express Figure 3 The shortest distance for the electromagnetic wave generated by the discharge point f in the first section to reach the node k is as follows:

[0087]

[0088] Where, τ, L l , They are Figure 3 The straight-line distance in .

[0089] (g i,k ,g j,k ) indicates that the discharge electromagnetic wave on the i-th line reaches the k-th node, and the maximum observability problem of the system can be abstracted into a 0-1 planning model:

[0090]

[0091] In the formula, This is the case where the Mth route passes through point i and reaches point k.

[0092] The (0-1) planning model is expressed in the following matrix form:

[0093]

[0094] Where: G 2R×N , I 2R×1 , B 2N×N , b 2n×1 are matrix constants, X T =[x1,x2,...,x N] is the configuration vector to be solved, with x k As a sign of whether a node is equipped with a sensor, the installation location of the sensor for global monitoring can be obtained.

[0095] In addition, if Figure 4 As shown, the second embodiment of the present invention proposes a GIS fault signal location system based on energy search, and the system includes:

[0096] The signal acquisition module 10 is used to acquire the fault signals synchronously collected by n sensors installed in the GIS equipment;

[0097] A comprehensive difference calculation module 20 is used to traverse the fault signal corresponding to each sensor, and calculate the comprehensive difference between the fault signal corresponding to the current sensor traversed and the fault signals corresponding to the remaining sensors;

[0098] The amplitude close determination module 30 is used to determine, for the fault signal corresponding to the current sensor that has been traversed, a fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors;

[0099] The fault range determination module 40 is used to determine the fault range detected by the current sensor according to the comprehensive difference corresponding to the current sensor and the most recently received fault signal;

[0100] The fault location determination module 50 is used to take the overlapping area of ​​the fault occurrence ranges corresponding to all sensors as the fault occurrence location.

[0101] As a further preferred technical solution, the comprehensive difference calculation module 20 is specifically used to calculate the comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors using a basic energy function. The basic energy function formula is expressed as:

[0102]

[0103] Where E(x) is the basic energy function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the other sensors, exp is the exponential function, log is the logarithmic function, d(x,x (i) ) represents the energy difference function.

[0104] As a further preferred technical solution, the amplitude proximity determination module 30 is specifically used to determine the fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors using an energy search function. The energy search function formula is expressed as:

[0105]

[0106] In the formula, g(x) is the energy search function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the remaining sensors, d(x,x (i) ) represents the energy difference function.

[0107] As a further preferred technical solution, the fault occurrence range determination module 40 includes:

[0108] The straight-line distance determination unit is used to determine the straight-line distance between the fault location and the current sensor location as:

[0109]

[0110] Where x is the fault signal detected by the current sensor.

[0111] The fault occurrence range determination unit is used to determine the fault occurrence range corresponding to each sensor using the straight-line distance corresponding to each sensor as a radius.

[0112] As a further preferred technical solution, the system further includes:

[0113] The sensor layout location optimization module is used to perform 0-1 planning on the internal structure of GIS equipment and determine the installation locations of sensors for global monitoring.

[0114] It should be noted that other embodiments or implementation methods of the GIS fault signal location system based on energy search described in the present invention can refer to the above-mentioned method embodiments, which will not be repeated here.

[0115] In addition, the present invention also proposes a GIS fault signal locating device, which includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the GIS fault signal locating method based on energy search as described in the first embodiment above.

[0116] In addition, the present invention also proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the energy search-based GIS fault signal location method as described in the first embodiment above is implemented.

[0117] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0118] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0119] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0120] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0121] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A GIS fault signal location method based on energy search, characterized in that: The method comprises: Obtain fault signals synchronously collected by n sensors installed in GIS equipment; Traverse the fault signal corresponding to each sensor, and calculate the comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors; For the fault signal corresponding to the current sensor traversed, determine the fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors; Determine the fault range detected by the current sensor based on the comprehensive difference corresponding to the current sensor and the most recently received fault signal; The overlapping area of ​​the fault occurrence ranges corresponding to all sensors is taken as the fault occurrence location.

2. The GIS fault signal location method based on energy search according to claim 1 is characterized in that: The formula for calculating the comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors is: Where E(x) is the basic energy function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the remaining sensors, exp is the exponential function, log is the logarithmic function, d(x, x (i) ) represents the energy difference function.

3. The GIS fault signal location method based on energy search according to claim 1 is characterized in that: For the fault signal corresponding to the current sensor traversed, the fault signal whose amplitude is closest to the fault signal corresponding to the current sensor is determined from the fault signals corresponding to the remaining sensors. The formula is expressed as: In the formula, g(x) is the energy search function, x is the fault signal detected by the current sensor, and x (i) is the fault signal detected by the remaining sensors, d(x, x (i) ) represents the energy difference function.

4. The GIS fault signal location method based on energy search according to claim 2 or 3, characterized in that: The formula of the energy difference function is expressed as: d(x,x (i) )=||x-x (i) || 2 In the formula, || || 2 represents the L2 norm.

5. The GIS fault signal location method based on energy search according to claim 1 is characterized in that: The method of determining the fault occurrence range detected by the current sensor according to the comprehensive difference corresponding to the current sensor and the most recently received fault signal includes: According to the comprehensive difference corresponding to the current sensor and the most recent fault signal, determine the straight-line distance Z between the fault location and the current sensor location t , the formula is: Where E(x) is the basic energy function, g(x) is the energy search function, and πe is a natural number; The fault occurrence range corresponding to each sensor is determined using the straight-line distance corresponding to the sensor as the radius.

6. The GIS fault signal location method based on energy search according to claim 5 is characterized in that: When the number of sensors n is 10, the straight-line distance between the fault location and the current sensor location is determined as: Where x is the fault signal detected by the current sensor.

7. The GIS fault signal location method based on energy search according to claim 1 is characterized in that: Before acquiring the fault signals synchronously collected by n sensors installed in the GIS device, the method further includes: Carry out 0-1 planning of the internal structure of GIS equipment and determine the installation locations of sensors for global monitoring.

8. A GIS fault signal location system based on energy search, characterized in that: The system comprises: The signal acquisition module is used to obtain the fault signals synchronously collected by n sensors installed in the GIS equipment; A comprehensive difference calculation module is used to traverse the fault signal corresponding to each sensor and calculate the comprehensive difference between the fault signal corresponding to the current sensor and the fault signals corresponding to the remaining sensors; An amplitude close determination module is used to determine, for the fault signal corresponding to the current sensor that has been traversed, a fault signal whose amplitude is closest to the fault signal corresponding to the current sensor from the fault signals corresponding to the remaining sensors; A fault range determination module is used to determine the fault range detected by the current sensor based on the comprehensive difference corresponding to the current sensor and the most recently received fault signal; The fault location determination module is used to take the overlapping area of ​​the fault occurrence ranges corresponding to all sensors as the fault occurrence location.

9. A GIS fault signal locating device, characterized in that: The device includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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