Binocular vision detection method, system and equipment for elevator buffer and medium

Abstract

The invention discloses a binocular vision detection method, system and equipment for an elevator buffer and a medium, and particularly relates to the field of elevator buffer detection. The binocular vision detection method for the elevator buffer comprises the steps that audio and video recording data of a no-load elevator in the buffer detection process are obtained, and the recording duration of the audio and video recording data at least comprises the whole process before the buffer is compressed, the whole process when the buffer is compressed and the whole process when a lift car leaves the buffer; generating three-dimensional models of the buffer at different moments based on the audio and video recording data; comparing the three-dimensional model of the buffer at the critical moment with a buffer initial model in a preset database, and generating difference data; and generating a detection result of the buffer based on the difference data. The method can accurately and effectively judge, confirm and measure the damage (such as obvious inclination, fracture, plastic deformation, peeling, damage and the like) which has adverse effects on normal use of the elevator, and the actual detection precision is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of elevator buffer detection, and in particular relates to a binocular vision detection method, system, device and medium for an elevator buffer. BACKGROUND

[0002] An elevator buffer is a device installed in the pit of an elevator shaft, which is used to absorb and reduce the impact energy when the elevator car or counterweight device falls accidentally, thereby protecting the elevator equipment, passengers in the car and other facilities in the shaft. As an elastomer buffer, the polyurethane buffer absorbs energy through its elastic deformation when impacted.

[0003] The polyurethane buffer needs to be visually inspected and compared before use, and audio and video recordings are also made.

[0004] At present, when visually inspecting and recording the audio and video of the polyurethane buffer, it is usually dependent on the on-site viewing and measurement of the inspector. It is impossible to quantify the deformation data of the polyurethane buffer, and it is also impossible to accurately obtain the measurement data. At the same time, since accurate measurement requires consistent measurement methods and measurement points, it is difficult to achieve with traditional measurement methods. When testing the polyurethane buffer, the reference comparison system of the appearance of multiple indicators before and after the test is easily changed, and accurate data of the appearance of multiple indicators cannot be obtained. SUMMARY

[0005] In view of the above shortcomings of the prior art, the purpose of the present application is to disclose a binocular vision detection method, system, device and medium for an elevator buffer, in order to improve the related problems mentioned in the above technical background.

[0006] To achieve the above object and other related objects, the present application discloses a binocular vision detection method for an elevator buffer, which comprises:

[0007] Step S10: obtaining audio and video recording data of an empty elevator during the execution of a buffer detection process, the recording duration of the audio and video recording data including at least the entire process of the buffer being compressed, being compressed and the car leaving the buffer;

[0008] Step S20: generating a three-dimensional model of the buffer at different times based on the audio and video recording data;

[0009] Step S30: comparing the three-dimensional model of the buffer at the key moment with the initial model of the buffer in the preset database, and generating difference data;

[0010] Step S40: generating a detection result of the buffer based on the difference data.

[0011] In one scheme of the present application, the step S10 further comprises:

[0012] The detection unit is arranged on one side of the buffer, and the detection unit comprises a binocular stereo camera and a line laser emitter.

[0013] The binocular stereo camera is connected with a swing mechanism, and the line laser emitter is arranged on the swing mechanism.

[0014] The swing mechanism can drive the line laser emitter to swing back and forth.

[0015] In one scheme of the present application, the step S10 further comprises:

[0016] The line laser emitter is driven by the swing mechanism to scan the buffer and obtain scanning data, and the binocular stereo camera captures images and obtains shooting data.

[0017] The audio and video recording data comprise the scanning data and the shooting data.

[0018] In one scheme of the present application, the step S20 comprises:

[0019] Based on the scanning data, depth data of different positions of the buffer at different time points is obtained.

[0020] Based on the depth data and the shooting data, a three-dimensional model of the buffer at different time points is generated through parallax calculation and three-dimensional point cloud model reconstruction.

[0021] In one scheme of the present application, the step S30 comprises:

[0022] The label information of the buffer in the test is obtained, and a corresponding initial model of the buffer in a preset database is retrieved based on the label information.

[0023] The key time points at least include a time point before compression and a time point after compression, and three-dimensional models at the time point before compression and the time point after compression are obtained.

[0024] The three-dimensional model at the time point before compression is compared with the initial model of the buffer to obtain first difference data.

[0025] The three-dimensional model at the time point after compression is compared with the initial model of the buffer to obtain second difference data.

[0026] In one scheme of the present application, the step S40 comprises:

[0027] Based on the difference data, determining the defect type and corresponding strategy of the buffer by querying a preset difference data-defect type-corresponding strategy comparison table;

[0028] The defect types include at least obvious tilt, fracture, plastic deformation, spalling, and breakage; and

[0029] The corresponding strategy at least includes whether the buffer can continue to be used or not.

[0030] The present invention also provides a system for binocular vision inspection of any of the above-mentioned elevator buffers, comprising:

[0031] a data acquisition module for acquiring audio and video recording data of an empty elevator during a buffer detection process, wherein the recording duration of the audio and video recording data at least includes the entire process before and during the compression of the buffer and the entire process of the car leaving the buffer;

[0032] a three-dimensional stereo generating module, configured to generate three-dimensional models of the buffer at different moments based on the audio and video recording data;

[0033] a comparison module, configured to compare the three-dimensional model of the buffer at a critical moment with an initial model of the buffer in a preset database and generate difference data; and

[0034] An output module is configured to generate a detection result of the buffer based on the difference data.

[0035] The present invention also provides an electronic device, comprising:

[0036] one or more processors; and

[0037] A memory storing computer program instructions, wherein the computer program instructions, when executed, cause the processor to perform the steps of any one of the methods described above.

[0038] The present invention also provides a computer-readable medium having a computer program / instruction stored thereon, wherein the computer program / instruction, when executed by a processor, implements the steps of any one of the methods described above.

[0039] In summary, the present invention discloses a binocular vision inspection method, system, device, and medium for elevator buffers. A line laser projector projects a linear laser onto the buffer surface, and a binocular stereo camera captures the deformation of the laser line on the surface. This deformation information is processed and analyzed to reconstruct a three-dimensional model of the buffer. This allows for accurate and intuitive acquisition of the actual status of the buffer, facilitating buffer inspection.

[0040] The binocular stereo camera can accurately and effectively determine and measure damages (such as obvious inclination, fracture, plastic deformation, peeling, breakage, etc.) that have adverse effects on normal use of the elevator. Meanwhile, the binocular stereo camera can not only identify and measure defects and damages of the polyurethane buffer before and after compression, but also record information of the whole process before and during compression of the buffer and the car (counterweight) leaving the buffer.

[0041] The swing mechanism adopts a telescopic arm structure, can be moved and rotated by a large margin, and can cover the range that needs to be measured and recorded. By determining the distance and angle of movement and rotation of the binocular stereo camera before and after compression of the buffer, that is, by determining and unifying the data comparison reference system before and after compression, the actual measurement accuracy is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0043] Figure 1 A flowchart of the binocular vision detection method for the elevator buffer in an embodiment of the present application;

[0044] Figure 2 A structure diagram of the detection unit in the binocular vision detection method for the elevator buffer in an embodiment of the present application;

[0045] Figure 3 A module diagram of the binocular vision detection system for the elevator buffer in an embodiment of the present application;

[0046] Figure 4 An exemplary structure diagram of an electronic device according to the present application.

[0047] Element number explanation

[0048] 010, binocular stereo camera; 011, line laser emitter; 012, swing mechanism;

[0049] 100, binocular vision detection system for the elevator buffer;

[0050] 10, data acquisition module; 20, three-dimensional stereo generation module; 30, comparison module; 40, output module;

[0051] 1101, processor; 1102, memory; 1103, input device; 1104, output device. DETAILED DESCRIPTION

[0052] The present application is herein described, by way of example only, with reference to embodiments thereof. It is construed that persons skilled in the art can easily appreciate other advantages and functions of the present application from the contents disclosed in this specification. The present application can also be implemented or applied by other different embodiments, and each detail in this specification can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0053] Please refer to Figures 1 to 4 . It is understood that the structure, proportion, size, etc. shown in the drawings of this specification are only used to cooperate with the contents disclosed in this specification for understanding and reading by those skilled in the art, and are not used to limit the defined conditions of the embodiments of the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical contents disclosed by the present application.

[0054] Please refer to the drawings of this specification Figure 1 , Figure 1 is a schematic diagram of the main steps of the binocular vision detection method of the elevator buffer according to an embodiment of the present application.

[0055] As shown in Figure 1 , the binocular vision detection method of the elevator buffer in the embodiments of the present application mainly includes the following steps S10-S40.

[0056] Firstly, step S10 is performed to obtain the audio-visual recording data of the empty elevator during the execution of the buffer detection process, and the recording time length of the audio-visual recording data at least includes the whole process before the buffer is compressed, during the compression, and when the car leaves the buffer.

[0057] Please refer to Figure 2 , in some embodiments, during the detection of the buffer of the elevator, the detection process needs to be recorded throughout the process. Based on this, a detection unit can be allowed to be provided, and the detection unit is provided on one side of the buffer.

[0058] Specifically, the detection unit includes a binocular stereo camera 010 and a line laser emitter 011. The binocular stereo camera 010 includes two cameras, an image processor, a storage module, and a communication interface. The two cameras are responsible for collecting image information of the object, and the image processor is used to process and analyze the images collected by the two cameras, including operations such as distortion removal, image matching, depth calculation, etc. It can be understood that the storage module is used to store the collected image data and the processed results for subsequent analysis and application. The communication interface is used to connect and communicate the binocular stereo camera 010 with other devices, for example, the communication interface can be USB, Ethernet, Wi-Fi, etc. Through the communication interface, the image data collected by the camera can be transmitted to a computer, a robot controller, etc. for further processing and application.

[0059] The line laser emitter 011 is located above the binocular stereo camera 010. Specifically, a swing mechanism 012 is connected to the binocular stereo camera 010, and the line laser emitter 011 is located on the swing mechanism 012. Therefore, the swing mechanism 012 can drive the line laser emitter 011 to swing back and forth.

[0060] In some embodiments, the specific structure of the swing mechanism 012 can be determined according to actual needs. For example, the swing mechanism 012 can be driven by a motor to realize the back-and-forth swinging of the line laser emitter 011. The line laser emitter 011 is a device that can emit a line-shaped laser, which cooperates with the binocular stereo camera 010 to realize three-dimensional modeling of the bumper.

[0061] It should be noted that the swing mechanism 012 can adopt a telescopic arm structure, which can be moved and rotated greatly, covering the range of measurement and audio-video recording, and can also be fixed conveniently and quickly. The distance and angle of movement and rotation of the line laser emitter 011 before and after the compression of the bumper are determined, that is, the reference system for comparing and referencing the data before and after the compression is determined and unified.

[0062] Specifically, the line laser emitter 011 projects a line-shaped laser onto the surface of the bumper, and the binocular stereo camera 010 captures the deformation of the laser line on the surface of the object. By processing and analyzing these deformation information, a three-dimensional model of the bumper is reconstructed.

[0063] Based on this, in step S10, when obtaining the audio-video recording data, the following steps can be implemented.

[0064] The line laser emitter 011 scans the buffer and acquires scanning data under the reciprocating swing of the swing mechanism 012, while the binocular stereo camera 010 takes images and acquires shooting data. It can be understood that the audio-visual recording data includes the scanning data and the shooting data. Through corresponding data processing of the scanning data and the shooting data, a three-dimensional model of the buffer is obtained.

[0065] Then, step S20 is performed, and a three-dimensional model of the buffer at different time instants is generated based on the audio-visual recording data.

[0066] In some embodiments, the processor acquires depth data of different positions of the buffer at different time instants based on the scanning data, and generates a three-dimensional model of the buffer at different time instants based on the depth data and the shooting data through parallax calculation and three-dimensional point cloud model reconstruction.

[0067] Specifically, in actual operation, depth data is acquired through the binocular stereo camera 010 and the line laser emitter 011. Since the depth data may contain noise or inaccurate parts, a filtering algorithm (such as median filtering, Gaussian filtering, etc.) can be used to remove salt and pepper noise or Gaussian noise in the depth data, and the quality of the data is improved. At the same time, the depth data and the shooting data are aligned in time and space. If there is a time stamp inconsistency or a different spatial coordinate system, correction is needed.

[0068] Secondly, the shooting data is usually the left and right view images acquired by the binocular stereo camera 010. Feature extraction is performed on the images, and the feature extraction method can include SIFT (Scale-Invariant Feature Transform), SURF (Speeded-Up Robust Features) or ORB (Oriented FAST and Rotated BRIEF), etc. Furthermore, in the left and right view images, matching is performed based on the extracted features. For example, for a feature point in the left view, a corresponding feature point in the right view is found. This can be achieved by similarity calculation of feature descriptors, such as calculating Euclidean distance or Hamming distance, etc.

[0069] Further, the parallax is calculated according to the coordinate difference of the matched feature points in the left and right views. It is allowed to set the feature point coordinates in the left view as (x l ,y), the matched feature point coordinates in the right view as (x r ,y), and the parallax d = x l -x r . Since the parallax has a corresponding relationship with the depth data, the actual depth value can be further converted through the principle of triangulation.

[0070] Specifically, for each matched feature point, its 3D coordinates are calculated according to the parallax and known camera parameters (such as focal length, baseline length, etc.).

[0071] For example, it can be assumed that in the camera coordinate system, the 3D coordinates of the feature point can be calculated according to the triangulation formula (where Z is the depth, f is the focal length, and b is the baseline length), and (where c x and c y are the coordinates of the camera optical center in the image plane).

[0072] Further, by repeating the above steps, the coordinates of all matched feature points are converted to obtain a series of 3D points, which constitute the preliminary point cloud data.

[0073] Finally, since there may be errors in the parallax calculation and coordinate conversion process, the generated point cloud needs to be optimized. Point cloud registration algorithms such as ICP (Iterative Closest Point) are used to register the point clouds obtained at different times to improve the accuracy and completeness of the point cloud.

[0074] Step S30 is performed to compare the 3D solid model of the buffer at the key moment with the initial model of the buffer in the preset database and generate difference data.

[0075] Specifically, since polyurethane buffers on the market come from different manufacturers, different models, and different batches, their sizes and materials are different. Therefore, a database of polyurethane buffers at the time of factory delivery can be preset and established, which at least includes the initial model of the buffer corresponding to different buffers. At the same time, the buffer corresponds to the label information, and the corresponding initial model of the buffer in the preset database can be retrieved based on the label information.

[0076] When judging the actual state of the buffer, the 3D solid model of the buffer at the key moment can be used. In this embodiment, the key moment includes at least the pre-compression moment and the post-compression moment, and the 3D solid models at the pre-compression moment and the post-compression moment are obtained. Therefore, by comparing the 3D solid model at the pre-compression moment with the initial model of the buffer, first difference data is obtained. And by comparing the 3D solid model at the post-compression moment with the initial model of the buffer, second difference data is obtained.

[0077] After obtaining the difference data, the actual state of the buffer is obtained by analyzing the difference data.

[0078] Finally, step S40 is performed to generate the detection result of the buffer based on the difference data.

[0079] Specifically, the difference data can be used to determine the buffer's defect type and corresponding strategy by querying a preset table of difference data, defect type, and corresponding strategy. The defect types include at least significant tilt, fracture, plastic deformation, spalling, and breakage, and the corresponding strategies include at least whether the buffer can continue to be used or cannot continue to be used.

[0080] It should be noted that the binocular stereo camera 010 can not only identify and measure defects and damage of the polyurethane buffer before and after compression, but also record the entire process information before the buffer is compressed, during compression, and when the car (counterweight) leaves the buffer, so as to improve the actual use effect of this device.

[0081] The steps of the various methods above are divided only for the purpose of clear description. During implementation, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process without changing the core design of the algorithm and process are all within the scope of protection of this patent.

[0082] It is worth mentioning that all modules involved in this embodiment are logical modules. In actual applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, to highlight the innovation of this application, this embodiment does not include units that are not closely related to solving the technical problems proposed by this application. However, this does not mean that other units do not exist in this embodiment.

[0083] See also Figure 3 The present invention also provides a binocular vision inspection system 100 for an elevator buffer, which at least includes a data acquisition module 10, a three-dimensional stereo generation module 20, a comparison module 30 and an output module 40.

[0084] Specifically, the binocular vision inspection method for an elevator buffer disclosed in the above embodiment can be applied to a binocular vision inspection system 100 for an elevator buffer.

[0085] Further, the data acquisition module 10 is configured to acquire audio-visual recording data of the empty elevator during the execution of the buffer detection process, and the recording time length of the audio-visual recording data at least includes the whole process before the buffer is compressed, during the buffer is compressed, and the car leaves the buffer. The three-dimensional generation module 20 is configured to generate three-dimensional models of the buffer at different time based on the audio-visual recording data. The comparison module 30 is configured to compare the three-dimensional models of the buffer at the key time with the initial model of the buffer in the preset database, and generate difference data. The output module 40 is configured to generate the detection result of the buffer based on the difference data.

[0086] The implementation of the binocular vision detection system 100 of the elevator buffer disclosed in the present solution is the same as the binocular vision detection method of the elevator buffer described above, and will not be repeated here.

[0087] Please refer to Figure 4 Some embodiments of the present application also provide an electronic device. The electronic device can be various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and the like. The electronic device can also be various forms of mobile devices, such as personal digital assistants, cellular phones, smart phones, wearable devices, and other similar computing devices. The electronic device includes one or more processors, and a memory storing computer program instructions that, when executed, cause the processor to perform the steps of the method provided by any one or more embodiments described above.

[0088] The electronic device can also include an input device 1103 and an output device 1104. The processor 1101, the memory 1102, the input device 1103, and the output device 1104 can be connected by a bus or other means, Figure 3 The input device 1103 can receive input digital or character information, and generate key signal input related to user settings and function control of the electronic device, such as touch screens, keypads, mice, trackpads, touchpads, pointing sticks, one or more mouse buttons, trackballs, joysticks, and the like. The output device 1104 can include display devices, auxiliary lighting devices (e.g., LEDs), and tactile feedback devices (e.g., vibration motors), and the like. The display device can include, but is not limited to, liquid crystal displays (LCDs), light-emitting diode (LED) displays, and plasma displays. In some embodiments, the display device can be a touch screen

[0089] Some embodiments of the present application further provide a computer readable medium having stored thereon computer programs / instructions which, when executed by a processor, implement the steps of the method provided by any one or more of the above embodiments. The computer readable medium can be included in the electronic device described in the above embodiments; or can exist separately and not be assembled into the device. The computer readable medium carries one or more computer readable instructions.

[0090] Some embodiments of the present application further provide a computer program product comprising one or more computer programs / instructions which, when executed by a processor, wholly or partially generate the processes or functions described in the embodiments of the present application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0091] The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) or can be connected to an external computer (such as using an Internet service provider to connect through the Internet).

[0092] In summary, the application discloses a kind of binocular vision detection method, system, equipment and medium of elevator buffer, linear laser is projected to the surface of buffer by linear laser emitter, and binocular stereo camera is photographed laser line deformation on object surface, three-dimensional model of buffer is reconstructed by processing and analysis to these deformation information. Actual state information of buffer can be accurately and intuitively obtained, so as to facilitate the detection of buffer. Binocular stereo camera can accurately judge and measure the damage (such as obvious inclination, fracture, plastic deformation, peeling, damage, etc.) that has adverse effect on normal use of elevator. At the same time, binocular stereo camera can not only identify and measure the defect and damage before and after compression of polyurethane buffer, but also record the whole process information before compression, during compression and car (counterweight) leaving buffer. And swing mechanism uses telescopic arm structure, can be moved and rotated greatly, can cover the range that needs to be measured and audiovisual recording. By determining the distance and angle of movement and rotation of binocular stereo camera before and after compression of buffer, i.e. determining and unifying the data comparison reference system before and after compression, the actual measurement accuracy is greatly improved.

[0093] Therefore, the present application effectively overcomes some practical problems in the prior art and has high utilization value and use significance.

[0094] The above embodiments are only illustrative of the principles of the present application and its efficacy, and are not intended to limit the present application. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. A binocular vision inspection method for elevator buffers, characterized in that: include: Step S10, obtaining audio and video recording data of an empty elevator during a buffer detection process, wherein the recording duration of the audio and video recording data at least includes the entire process before and during the compression of the buffer and the entire process of the car leaving the buffer; Step S20, generating a three-dimensional model of the buffer at different times based on the audio and video recording data; Step S30, comparing the three-dimensional model of the buffer at the critical moment with the initial model of the buffer in a preset database, and generating difference data; Step S40: generating a detection result of the buffer based on the difference data.

2. The binocular vision inspection method for elevator buffers according to claim 1, characterized in that: In the step S10, it further includes: A detection unit is arranged on one side of the buffer, and the detection unit includes a binocular stereo camera and a line laser transmitter; The binocular stereo camera is connected to a swing mechanism, and the line laser transmitter is located on the swing mechanism; The swing mechanism can drive the line laser emitter to swing back and forth.

3. The binocular vision inspection method for elevator buffers according to claim 2, characterized in that: In the step S10, it further includes: The line laser emitter scans the buffer and acquires scanning data under the reciprocating swing of the swing mechanism, while the binocular stereo camera captures images and acquires shooting data; The audio and video recording data includes the scanning data and the shooting data.

4. The binocular vision inspection method for elevator buffers according to claim 3, characterized in that: In step S20, it includes: Based on the scan data, acquiring depth data of different positions of the buffer at different times; Based on the depth data and the shooting data, a three-dimensional stereo model of the buffer at different times is generated through parallax calculation and three-dimensional point cloud model reconstruction.

5. The binocular vision inspection method for elevator buffers according to claim 1, characterized in that: In step S30, it includes: Obtaining the buffer label information in the test, and retrieving the corresponding buffer initial model in a preset database based on the label information; The key moments include at least a pre-compression moment and a post-compression moment, and three-dimensional models of the pre-compression moment and the post-compression moment are obtained; comparing the three-dimensional model before compression with the initial model of the buffer to obtain first difference data; The three-dimensional model at the time of compression is compared with the initial model of the buffer to obtain second difference data.

6. The binocular vision inspection method for elevator buffers according to claim 1, characterized in that: In step S40, it includes: Based on the difference data, determining the defect type and corresponding strategy of the buffer by querying a preset difference data-defect type-corresponding strategy comparison table; The defect types include at least obvious tilt, fracture, plastic deformation, spalling, and breakage; and The corresponding strategy at least includes whether the buffer can continue to be used or not.

7. A system for binocular vision inspection of elevator buffers according to any one of claims 1 to 6, characterized in that: include: a data acquisition module for acquiring audio and video recording data of an empty elevator during a buffer detection process, wherein the recording duration of the audio and video recording data at least includes the entire process before and during the compression of the buffer and the entire process of the car leaving the buffer; a three-dimensional stereo generating module, configured to generate three-dimensional models of the buffer at different moments based on the audio and video recording data; a comparison module, configured to compare the three-dimensional model of the buffer at a critical moment with an initial model of the buffer in a preset database and generate difference data; and An output module is configured to generate a detection result of the buffer based on the difference data.

8. An electronic device, characterized in that: The electronic device comprises: one or more processors; and A memory storing computer program instructions, which, when executed, cause the processor to perform the steps of the method according to any one of claims 1 to 6.

9. A computer-readable medium having a computer program / instruction stored thereon, 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 6 are implemented.

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