Multi-layer welding track planning method and automatic welding method

Abstract

The multi-layer welding track planning method for the saddle type welding seam is provided, a saddle type welding seam theoretical groove model is generated, and a corrected welding seam groove model is obtained; circumferentially determining a plurality of feature points and feature welding seam sections of the feature points along the corrected welding seam groove model; calculating the area of the section of each characteristic welding seam, determining the empirical value of the area of a single welding seam, and determining the number of layers and the area of the single-layer welding seam according to the area of the section of each characteristic welding seam and the empirical value of the area of the single welding seam; fitting weld joint area scaling coefficients of the layer at different weld joint positions by using single-layer weld joint areas of different feature points under the same layer; scaling the sectional area of the single-layer weld joint according to the weld joint area scaling coefficient to obtain the sectional area of the single-layer weld joint at other weld joint positions except the feature points; and a planned welding track of each layer is formed by connecting lines of mass centers of single-layer weld joint sections under each layer. The invention further provides an automatic argon arc welding method for the saddle type welding seam and a computer readable medium for storing commands.

Description

Technical Field

[0001] The invention relates to the field of argon arc welding, in particular to the field of welding methods for saddle-shaped welds. Background Art

[0002] The saddle weld of the riding branch pipe is a complex three-dimensional curved weld. There is a large height deviation and weld width deviation between the highest point weld and the lowest point weld of the saddle weld. It is time-consuming and labor-intensive to realize the welding of the saddle weld by manual teaching. Summary of the invention

[0003] An object of the present invention is to provide a multi-pass welding trajectory planning method for a saddle-type weld, so as to automatically realize the automatic planning of the multi-pass weld.

[0004] The multi-pass welding trajectory planning method for achieving the above-mentioned purpose comprises the following steps: generating a saddle-shaped weld theoretical groove model, using the actual weld groove size to correct the weld theoretical groove model to obtain a corrected weld groove model; determining multiple feature points and the characteristic weld cross-section of each feature point along the corrected weld groove model in a circumferential direction; calculating the area of ​​each characteristic weld cross-section, determining the empirical value of the single-pass weld area of ​​each feature point, and determining the number of layers and the single-pass weld area according to the characteristic weld cross-section area and the empirical value of the single-pass weld area; using the single-pass weld area of ​​different feature points under the same layer to fit the weld area scaling coefficient of the layer at different weld positions; scaling the single-pass weld cross-sectional area according to the weld area scaling coefficient to obtain the single-pass weld cross-sectional area at other weld positions other than the feature point; and forming the planned welding trajectory of each layer by connecting the centroids of the single-pass weld cross-section under each layer.

[0005] In one or more embodiments, within the 1 / 4 trajectory range of the modified weld groove model, the highest point, the lowest point, and the middle point between the highest point and the lowest point are selected as the feature points.

[0006] In one or more embodiments, the characteristic weld cross section is simplified using a simplified weld model, and layer division is performed to obtain the number of layers and the single-layer weld area.

[0007] In one or more embodiments, a plurality of empirical values ​​of single-pass weld area are used to pre-divide the weld into layers, and the optimal empirical value is selected as the empirical value of the single-pass weld area.

[0008] In one or more embodiments, the weld cross-sectional area from the second weld to the last weld at each weld position is scaled, and the first weld at each weld position is not scaled.

[0009] In one or more embodiments, a weld cross-sectional area enlargement threshold and a weld cross-sectional area reduction threshold are set.

[0010] In one or more embodiments, the sizes of the first welded pipe and the second welded pipe forming the saddle weld are determined, and the theoretical groove model of the saddle weld is generated.

[0011] Another object of the present invention is to provide an automatic argon arc welding method for a saddle-type weld, comprising the following steps: using the above-mentioned trajectory planning method to obtain the welding planning trajectory of each layer of welds; dynamically calculating the area on the trajectory of each layer of welds according to the current welding point during welding, and dynamically adjusting the wire feeding amount and welding current parameters during welding; using sensors to optimize the fitting of real-time weld and groove data with the data under the welding planning trajectory of each layer of welds, and correcting the trajectory route of each layer in real time.

[0012] In one or more embodiments, after welding is completed, it is determined whether the welding planning trajectory of each layer of weld is reasonable, and the reasonable welding planning trajectory is stored under the saddle-type weld size specification.

[0013] In one or more embodiments, laser sensors and arc voltage tracking technology are used to correct the trajectory of each layer in real time.

[0014] In one or more embodiments, the first weld trajectory point at the fitting position in the highest point cross section is fitted and aligned with the first weld arc starting point.

[0015] Another object of the present invention is to provide a computer-readable medium storing commands for storing a computer program / instruction, wherein the computer program / instruction implements the steps of the above method when executed by a processor.

[0016] The above-mentioned multi-layer welding trajectory planning method for saddle-type welds is further optimized on the basis of the equal-area weld arrangement principle to realize the automatic planning of multi-layer welds for saddle-type welds. It is suitable for various complex situations such as welds of unequal heights, and provides essential pre-input for realizing the automation of the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0018] Figure 1 is a schematic diagram of a first welded pipe, a second welded pipe and a saddle weld;

[0019] Figure 2 It is a schematic diagram of the highest point of the weld;

[0020] Figure 3 yes Figure 2The enlarged view of point A in the middle;

[0021] Figure 4 It is a schematic diagram of the area of ​​the weld cross section at the highest point;

[0022] Figure 5 It is a schematic diagram of the lowest point of the weld;

[0023] Figure 6 yes Figure 5 The enlarged view of point B in the middle;

[0024] Figure 7 It is a schematic diagram of the midpoint;

[0025] Figure 8 yes Figure 7 Enlarged view of point C in the middle;

[0026] Fig. 9 It is a schematic diagram of a multi-pass weld at the highest point of the weld;

[0027] Fig.10 It is a schematic diagram of the trapezoidal weld model;

[0028] Fig.11 It is a schematic diagram of a multi-pass weld at the lowest point of the weld;

[0029] Fig.12 It is a schematic diagram of a multi-pass weld at the midpoint;

[0030] Fig.13 It is a schematic diagram of the argon arc welding principle;

[0031] Fig.14 It is a schematic diagram of a specific implementation process of a multi-layer welding trajectory planning method and an automatic welding method;

[0032] Fig.15 It is a flow chart of the multi-layer welding trajectory planning method;

[0033] Fig.16 It is a schematic diagram of the cross-sectional area scaling relationship. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0035] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0036] Figure 1 The schematic diagram of the saddle weld of the riding branch pipe is shown. The first welding pipe 1 and the second welding pipe 2 are respectively used as the main pipe and the branch pipe, and are welded to form a saddle weld 3. The saddle weld 3 is a symmetrical structure, and has the highest point and the lowest point of the weld within the 1 / 4 trajectory range of the groove. The cross-sectional shapes of the welds at different positions are different, and the depth and angle of the welds are also different. At present, nuclear power plants mostly use manual argon arc welding for welding of this type of saddle welds, resulting in low welding production efficiency and high construction costs. Therefore, automatic welding gun trajectory planning is required at different weld positions.

[0037] Chinese patent CN116727805A discloses an automatic welding method, which uses a 3D scanning device to scan the weld in the welding area to generate three-dimensional point cloud data, extracts the weld feature value through an intelligent algorithm, locates the weld before welding, determines the starting point and the end point, and the system automatically plans the path of the workpiece to be welded, transmits the welding path to the welding equipment, and the welding equipment welds the workpiece to be welded according to the welding path. During the welding process, the welding path is adjusted and optimized by a point laser sensor. However, this automatic welding method is carbon dioxide gas shielded welding; this method can only automatically plan the path of the workpiece to be welded, and cannot automatically plan the path of multi-layer welds.

[0038] China's public patent CN117532226A discloses a method for dynamic intelligent planning of multi-layer thick-walled component robot adaptive welding layers. Based on the welding parameters of the base weld and the weld size model of the back of the base weld, the height of the front weld of the base weld is calculated, and the intelligent planning of the welding layers is realized by simplifying the welding model. However, this method is based on the principle of global equal height and local equal area, requiring that the height of each filling layer of the front weld of the base weld is fixed, which has great limitations and is not suitable for the situation where the weld height changes and the local area also changes.

[0039] Based on this, the present invention proposes a multi-layer welding trajectory planning method for saddle-type welds, which is further optimized on the basis of the equal-area weld arrangement principle to realize multi-layer and multi-pass automatic planning of saddle-type welds, providing essential pre-input for realizing the automation of the welding process, thereby improving welding efficiency and ensuring stable welding quality.

[0040] The trajectory planning method specifically includes the following steps. It should be noted that the description order of the following steps does not necessarily constitute the order of implementation process.

[0041] Firstly, the size of the first welded pipe and the size of the second welded pipe forming the saddle weld are determined, for example, the diameter of the first welded pipe Φ1 and the diameter of the second welded pipe Φ2, and a theoretical groove model of the saddle weld is generated, that is, the theoretical groove model of the saddle weld is generated based on the combination of the upstream pipe size model and the downstream size model of the saddle weld.

[0042] Subsequently, the actual weld groove size is used to correct the weld theoretical groove model to obtain a corrected weld groove model. For example, a laser sensor is used to scan the solid saddle-shaped weld groove, and the scanned data is processed in combination with the saddle-shaped weld theoretical groove model to correct the saddle-shaped theoretical groove model, and the complete saddle-shaped corrected weld groove model is obtained in combination with the relevant welding standards for the relevant size requirements of the saddle-shaped weld after welding.

[0043] Multiple feature points and the characteristic weld cross section of each feature point are determined along the circumferential direction of the modified weld groove model. In some embodiments, key feature points are selected. The saddle weld is axisymmetric in spatial position, and within the 1 / 4 trajectory range of the modified weld groove model, it can reflect the typical feature points of the saddle weld curve in the circumferential direction Q. The highest point 101, the lowest point 102, and one or more intermediate points 103 between the highest point and the lowest point of the weld are selected as feature points, and the number of feature points is selected according to the size of the pipeline. The theoretical weld cross section at the feature point is obtained through the model.

[0044] The weld model is meshed, and the area S of each characteristic weld section is calculated. The empirical value S' of the argon arc welding single-pass weld area of ​​each characteristic point is determined, and the number of layers K and the single-pass weld area are determined according to the characteristic weld cross-sectional area S and the empirical value S' of the single-pass weld area. The empirical value S' of the argon arc welding single-pass weld area is an empirical value, and multiple empirical values ​​of the single-pass weld area are used to pre-divide the weld into layers, and the optimal empirical value is selected as the empirical value of the single-pass weld area. The optimal empirical value includes, but is not limited to, a value that can make the welding process stable or a value that is most commonly used in practice.

[0045] The division principle follows the same number of passes in the same layer and the same total weld pass, so that the number of passes in each characteristic point is consistent. The weld passes are numbered in the same rule a, b, c, d, e..., and numbered in sequence from the root to the cover, that is, the welding order of the weld passes. Fig. 9 In the embodiment of the weld layer division at the highest point 101 of the weld shown, a represents the first weld layer, j represents the last weld layer, and based on the principle of the same number of layers, along the circumferential direction Q, the number of layers at each position of the saddle-shaped weld is 10.

[0046] When constructing a single-layer automatic TIG wire-filled weld section and dividing the layers, the single-layer weld section is simplified using simplification rules. For example, the complete saddle weld theoretical model is meshed using 3D model software and introduced Fig.10 The trapezoidal weld model shown is based on the principle that the cross-sectional area of ​​a single weld is the same when the welding speed remains unchanged. Based on the empirical value S' of the single-pass weld area of ​​argon arc welding, the saddle-type weld theoretical model is divided to obtain the number of layers and the single-layer weld area.

[0047] The trapezoidal weld model simplifies the overall weld into a combination of a trapezoid and other shapes, with calculable parameters such as the upper base, lower base and height, through which the geometric dimensions of the weld can be quantitatively described.

[0048] When the total number of welding layers is the same, the original single-pass trapezoidal reference weld cross section is enlarged or reduced in proportion, and the welding cross section at any time (any position) in the 1 / 4 trajectory is divided into multiple layers and multiple passes, and the multi-layer and multi-pass arrangement division trajectory of all cross sections is fitted. Fig.16 As shown in the figure, x represents any time (any position) in the 1 / 4 trajectory, S represents the cross-sectional area of ​​the layer, and the single-layer weld area of ​​different feature points under the same layer is used to fit the weld area scaling coefficient of the layer at different weld positions. The single-layer weld cross-sectional area is scaled according to the weld area scaling coefficient to obtain the single-layer weld cross-sectional area at other weld positions other than the feature points, as shown in point U.

[0049] For example, after selecting the highest point 101, the lowest point 102 and the middle point 103 as three characteristic points, the cross-sectional area of ​​each layer of welds at the three positions is obtained. Using the three characteristic points under the same layer, for example, as the single layer weld area under the e layer of the 5th layer, the weld area scaling coefficient of the layer at different weld positions is fitted. For example, the e layer weld area coefficients of the fourth position 104 and the fifth position 105 between the highest point 101 and the lowest point 102 are k 4 , k 5 By scaling and fitting the weld area using the scaling factor of the specific position, for example, the weld area values ​​of the e-layer at the fourth position 104 and the fifth position 105 between the highest point 101 and the lowest point 102 can be obtained.

[0050] When the original single-pass trapezoidal reference weld section is enlarged or reduced in proportion, the upper and lower thresholds are set, and the thresholds are affected by factors such as welding parameters and welding materials. In addition, when the welding section at any time is divided into multiple layers and multiple passes, in order to ensure the quality of the first base weld, the first base weld is not enlarged or reduced in proportion to the original single-pass trapezoidal reference weld section, and only the second weld to the last weld are scaled and fitted.

[0051] After obtaining the weld area of ​​any layer at each time and position in the circumferential direction of the weld, connect the centroids of the single-layer weld sections under each layer, that is, take the centroid of the divided area as the trajectory point of each weld to form the planned welding trajectory of each layer. For example, the area centroid point of each weld is generated according to the three-dimensional model algorithm, the first weld trajectory point at the fitting point in the highest point section is fitted with the highest arc starting point, and all the weld centroid points with the same number are connected in sequence to form a weld trajectory, and then a closed-loop weld trajectory is formed through symmetrical mirroring, and finally a multi-layer and multi-pass weld automatic arrangement trajectory of the entire weld is formed.

[0052] Combined with the introduction of the above-mentioned multi-layer welding trajectory planning method, we can understand an automatic argon arc welding method for saddle-type welds. This method uses the above-mentioned trajectory planning method to obtain the welding planning trajectory of each layer of welds. During the welding process, the area on the trajectory of each layer of welds is dynamically calculated according to the current welding point, and the welding wire feed amount that matches the use at a given welding speed is calculated. The applicable welding current parameters are matched to complete the welding of each weld.

[0053] During the welding process, laser sensors and arc voltage tracking technology can also be used to correct the trajectory of each layer in real time. For example, sensors can be used to optimize the fitting of real-time weld and groove data with the data under the welding planning trajectory of each layer of welds, and the welding trajectory can be corrected in time. During the welding process, the center of the welding arc is corrected in real time through line laser scanning to ensure that the arc trajectory on the theoretical trajectory and the actual workpiece trajectory are consistent as much as possible.

[0054] During and after the welding process, the automatically generated multi-layer and multi-pass trajectory routes are judged to be reasonable, and the reasonable models are saved in combination with the input specifications and dimensions; if they are unreasonable, their single-pass weld section models will be optimized, and the multi-layer and multi-pass automatic planning will be optimized.

[0055] It should be noted that the automatic welding method described in the present disclosure is suitable for argon arc welding, such as Fig.13 As shown, the welding process uses a tungsten needle 201 and a wire feed 202 to generate an arc in an inert gas, melt the base material through the arc heat, and form a molten pool at the welding position with the wire feed 202, and finally form a weld. The traditional welding method only needs to control the end of the welding wire to complete the saddle-shaped trajectory, but the argon arc welding used in the present disclosure needs to control the two points of the tungsten needle 201 and the wire feed 202 at the same time to change the saddle-shaped trajectory, that is, control the line segment 203 formed by the end of the tungsten needle and the end of the wire feed to achieve the saddle-shaped trajectory. Therefore, the saddle-shaped trajectory of the wire feed end needs to be considered as the tungsten needle trajectory movement before ΔT time plus a certain offset, which is significantly different from the common gas shielded welding.

[0056] Refer to the following Fig.14 , a specific embodiment of the method is introduced in detail.

[0057] Build a single-pass automatic TIG weld cross-section model, enter the upstream pipe diameter, select the downstream product type, enter the downstream size type, and build a saddle-type weld groove model.

[0058] Plan the robot arm motion trajectory, start the laser sensor to scan the original saddle weld, obtain the corresponding groove information, as well as the highest and lowest position information, and correct the saddle weld groove model. According to the relevant welding standard (RCC-M-2007B3353.2.C), the minimum thickness Tc of the saddle weld is the smaller of 0.7 times the nominal thickness of the downstream product or 6mm, and generate a complete corrected saddle weld groove model.

[0059] The saddle weld model is meshed, the weld is simplified into a trapezoid, and the area of ​​the weld cross section of each characteristic point is calculated. The saddle weld is axisymmetric in space, and the 1 / 4 circular trajectory between the highest point and the lowest point is analyzed. At any time in the 1 / 4 trajectory, several weld cross sections are meshed.

[0060] Under the condition of constant welding speed, based on the principle of the same cross-sectional area of ​​single-pass welds and combined with the simplified model of single-pass automatic TIG weld cross-section, the theoretical model of saddle-type welds is divided, and the number of welding layers is obtained based on the empirical data of the argon arc welding weld cross-section. The weld cross-section is arranged in multiple layers, and the total number of optimal multi-layer and multi-pass arrangement divisions is taken to determine the total number of layer divisions.

[0061] Under the condition that the total number of welding layers is consistent, the welding section at any time in the 1 / 4 trajectory is divided into multiple layers and multiple passes by enlarging or reducing the original single-pass trapezoidal reference weld section in equal proportion, and the multi-layer and multi-pass arrangement and division trajectory of all sections is fitted. Specifically, the welds are numbered in the same rule, that is, they are numbered in sequence from the root to the cover, that is, the welding order of the welds, and the area centroid point of each weld is generated according to the three-dimensional model algorithm. The first weld trajectory point at the fitting point in the highest point section is fitted with the highest arc starting point, and all the weld centroid points with the same number are connected in sequence to form the trajectory of the weld, and then a closed-loop weld trajectory is formed by symmetrical mirroring, that is, the center trajectory of the arc during multi-layer welding; finally, the multi-layer and multi-pass weld automatic arrangement trajectory of the entire weld is formed.

[0062] During the welding process, the arc voltage automatic tracking system is used to adjust the welding height in real time and correct the multi-layer layout trajectory.

[0063] During the welding process, the laser sensor optimizes and fits the weld and weld groove data with the original data in real time, and the system corrects the multi-layer and multi-channel automatic arrangement trajectory in real time.

[0064] By calculating the area of ​​each weld cross section, the amount of wire feed used is calculated at a given welding speed. The weld volume of argon arc welding is approximately equal to the wire feed volume, and then the applicable welding current parameters are matched. By calculating and fitting the area of ​​each weld on the key point cross section, a model of the entire weld is generated. During the welding process, the area on the weld trajectory is dynamically calculated according to the current welding point. During the welding process, the wire feed amount and welding current parameters are dynamically adjusted to complete the welding of each weld.

[0065] During and after the welding process, the automatically generated multi-layer and multi-pass trajectory routes are judged to be reasonable, and the reasonable models are saved in combination with the input specifications and dimensions; if they are unreasonable, their single-pass weld section models will be optimized, and the multi-layer and multi-pass automatic planning will be optimized.

[0066] The above method can realize the automatic generation of multi-layer welding trajectory of saddle-type welds, and realize adaptive correction during welding through automatic arc voltage tracking technology and laser sensors. Conventional multi-layer and multi-pass automatic planning technology is not suitable for special welds such as saddle-type welds. Therefore, this method can significantly improve the automatic welding efficiency and welding quality of saddle-type welds.

[0067] It should be noted that the use of terms such as "first" and "second" in the above introduction to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and do not represent priority, and therefore cannot be understood as limiting the scope of protection of this application.

[0068] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0069] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A multi-pass welding trajectory planning method for a saddle-type weld, characterized in that: The steps include: Generate a saddle-shaped weld groove theoretical model, and use the actual weld groove size to correct the weld groove theoretical model to obtain a corrected weld groove model; Determining a plurality of characteristic points and characteristic weld cross sections of each characteristic point circumferentially along the modified weld groove model; Calculating the area of ​​each characteristic weld cross section, determining the empirical value of the single weld area of ​​each characteristic point, and determining the number of layers and the single weld area according to the characteristic weld cross section area and the empirical value of the single weld area; The single-layer weld area of ​​different feature points in the same layer is used to fit the weld area scaling coefficient of the layer at different weld positions; Scaling the cross-sectional area of ​​the single-layer weld according to the weld area scaling coefficient to obtain the cross-sectional areas of the single-layer weld at other weld positions other than the characteristic point; The centroid lines of the single-layer weld cross sections under each layer are connected to form the planned welding trajectory for each layer.

2. The planning method according to claim 1, characterized in that: Within the 1 / 4 trajectory range of the modified weld groove model, the highest point, the lowest point, and the middle point between the highest point and the lowest point of the weld are selected as the feature points.

3. The planning method according to claim 1, characterized in that: The characteristic weld cross section is simplified using a simplified weld model, and layer division is performed to obtain the number of layers and the single-layer weld area.

4. The planning method according to claim 1, characterized in that: A plurality of single-pass weld area empirical values ​​are used to pre-divide the weld into layers, and the optimal empirical value is selected as the single-pass weld area empirical value.

5. The planning method according to claim 1, characterized in that: The weld cross-sectional area from the second weld to the last weld at each weld position is scaled, and the first weld at each weld position is not scaled.

6. The planning method according to claim 5, characterized in that: Set the weld cross-sectional area enlargement threshold and weld cross-sectional area reduction threshold.

7. The planning method according to claim 1, characterized in that: The sizes of the first welded pipe and the second welded pipe forming the saddle weld are determined, and the theoretical groove model of the saddle weld is generated.

8. The argon arc welding automatic welding method of saddle type weld is characterized by: Using the trajectory planning method as described in any one of claims 1 to 7 to obtain the welding planning trajectory of each layer of welds; During welding, the area of ​​each layer of the weld track is dynamically calculated according to the current welding point, and the wire feeding amount and welding current parameters are dynamically adjusted during welding; Sensors are used to optimize the fitting of real-time weld and groove data with the data of the welding planning trajectory of each layer of welds, and the trajectory route of each layer of welds is corrected in real time.

9. The automatic welding method according to claim 8, characterized in that: After welding is completed, it is determined whether the welding planning trajectory of each layer of welds is reasonable, and the reasonable welding planning trajectory is stored under the saddle-shaped weld size specification.

10. The automatic welding method according to claim 8, characterized in that: Use laser sensors and arc voltage tracking technology to correct the trajectory of each layer in real time.

11. The automatic welding method according to claim 8, characterized in that: Fit and align the first weld trajectory point at the fitting point in the highest point section with the first weld arc starting point.

12. A computer readable medium storing commands for storing computer programs / instructions, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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