Sliding window inversion method and system based on cross-hole resistivity CT

Abstract

The application provides a cross-hole resistivity CT based sliding window inversion method and system. In deep hole data acquisition, the acquisition device designed by the application can automatically wind and unwind the cable, adjust the electrode position, and realize sufficient acquisition of data in the deep hole interval detection area by using a small number of electrodes. In data processing, the detection area is divided into blocks by using a variable window, and each block is independently inverted using the data in the block. After increasing the window, the detection area is divided into blocks again, and the inversion is performed layer by layer from a small area to a large area. The application improves the acquisition efficiency, improves the inversion imaging effect, and realizes effective detection of the deep hole area anomaly body.

Description

Technical Field

[0001] This invention belongs to the field of geophysical exploration technology and relates to a sliding window inversion method and system based on transpore resistivity CT. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Transpore resistivity CT is a branch of DC resistivity imaging. It is based on the resistivity difference between different media in the pore and solves geological problems by observing and studying the distribution law of artificially established geoelectric field. It has been widely used in highways, railways, water conservancy and hydropower and other fields.

[0004] Trans-hole resistivity CT places electrodes in the borehole, using various combinations of electrodes for power supply and measurement. The acquired potential data is used to generate a resistivity model through inversion technology, and then the image is used for geological interpretation. However, existing technologies have significant limitations for deep borehole exploration. This is because existing electrical resistivity instruments, without expansion equipment, typically only support a few dozen electrodes. To achieve trans-hole resistivity CT imaging between deep boreholes, there are three approaches: ① Increase the electrode spacing, so that the electrodes are evenly distributed in the borehole from top to bottom. Using cables with a large electrode spacing can quickly complete data acquisition and inversion imaging. However, since the maximum resolution is no more than half the electrode spacing, using a large electrode spacing will result in poor imaging quality and difficulty in accurately identifying geological anomalies. ② Divide the exploration area between boreholes into segments, measure and invert each segment separately, and finally stitch the imaging results of each segment together. Due to the ambiguity of the electrical resistivity inversion problem, there are often obvious seams at the stitching points. In addition, the background resistivity values ​​of the inversion results of different segments vary, making subsequent geological interpretation difficult. ③ Divide the exploration area between boreholes into segments, measure each segment separately, and then merge all the segment data for inversion imaging. Because the inversion requires many parameters and has a higher ambiguity, the imaging results will contain a large number of false anomalies, ultimately leading to incorrect geological interpretation.

[0005] In summary, under current technological conditions, the use of transpore resistivity CT imaging in deep holes still faces the following two challenges:

[0006] Firstly, there is a lack of trans-hole resistivity CT data acquisition devices suitable for deep boreholes. How to fully acquire effective information from the entire deep borehole using conventional electrical resistivity equipment (electrical resistivity meter, cable, electrodes, etc.) to meet the resolution requirements of geological exploration is a problem that needs to be solved.

[0007] Secondly, there is a lack of transpore resistivity CT inversion methods suitable for deep holes. Deep hole imaging involves large amounts of data, numerous parameters to be calculated, slow inversion solution speed, and many false anomalies. How to quickly and accurately invert and image deep hole data is a problem that needs to be solved. Summary of the Invention

[0008] To address the aforementioned problems, this invention proposes a sliding window inversion method and system based on transpore resistivity CT, which can fully acquire and rapidly invert deep hole data and effectively improve the inversion imaging effect.

[0009] According to some embodiments, the present invention adopts the following technical solution:

[0010] A sliding window inversion method based on transpore resistivity CT includes the following steps:

[0011] (1) Determine the detection area according to the engineering requirements, set up a tripod above the two detection holes, and install guide distance measuring pulleys;

[0012] (2) Set the spatial locations that the electrodes need to traverse and the parameters for cable deployment and retraction;

[0013] (3) The cable is connected to the main unit of the electrical resistivity meter via the guide distance measuring pulley. The cable is lowered until all electrodes are below the water level, and the initial position of the electrodes is recorded. Data is collected from all electrodes through the main unit of the electrical resistivity meter.

[0014] (4) Lower the first cable in the first probe hole step by step so that all electrodes on the first cable are lower than the lowest position of the electrodes in the previous stage. Record the position of each stage of electrodes and collect data on the electrodes on the first cable at each stage of electrodes.

[0015] (5) After the first cable is lowered to the lowest end and data acquisition is completed, it is raised to the initial position, and the second cable in the second probe hole is lowered one level so that all electrodes on the second cable are lower than the lowest position of the electrodes of the previous level. The current electrode position is recorded and data is collected on the electrodes on the second cable. Then, return to step (4).

[0016] (6) Repeat steps (4) and (5) until the first cable and the second cable are both placed at the lowest end, the electrodes traverse all preset positions, and complete the acquisition of electrode data at each position, that is, the data of the entire deep hole has been fully acquired, and these data are used for subsequent inversion imaging.

[0017] (7) Set the sliding window size and inversion parameters, divide the entire detection area equally according to the window size, and invert each area independently;

[0018] (8) Increase the window size, re-divide the detection area, use the previous inversion result as the initial model, invert the new area, and iterate and repeat step (8) until the window covers the entire area; obtain the final resistivity model and image it.

[0019] As an alternative implementation, the data acquisition equipment consists of two parts: a transpore resistivity CT device and a lifting device. The transpore resistivity CT device mainly includes: a cable with electrodes mounted on it, an electrical resistivity meter main unit, and a battery. The lifting device comprises a tripod, a guide rangefinder pulley, and a cable reel. The guide rangefinder pulley is the rope guide pulley in a wheel-type rangefinder; the number of rotations of the pulley corresponds to the length of the rope lowered. The wheel-type rangefinder is used to measure the position of the electrode in the borehole and the height of lowering or raising it. The guide rangefinder pulley is mounted on the tripod. The cable is wound around the cable reel; one end with the electrode is lowered into the detection borehole via the guide rangefinder pulley, and the other end is connected to the electrical resistivity meter main unit.

[0020] The reel is driven by a motor and can automatically rotate to wind up and unwind the cable after data acquisition is completed, moving the cable and electrode to the next position.

[0021] The tripod and guide distance measuring pulley are used to record the depth position of the electrode points. By using the initial position of the first electrode, the electrode spacing, and the value of the distance measuring pulley, the positions of all electrode points can be derived.

[0022] As an alternative implementation, the cables used in transpore resistivity CT equipment each have 20-40 electrodes arranged on both the first and second cables, which conforms to the centralized cable configuration currently used by mainstream electrical resistivity CT manufacturers. The electrode spacing is approximately 1-3 meters, determined by the required detection resolution, and is typically twice the distance of the resolution.

[0023] As an alternative implementation, the electrical resistivity meter main unit acquires electrode data via a preset observation device. This preset observation device is typically a quadrupole setup, where power supply points A and B, and measurement points M and N, are both located within the holes. Conventional quadrupole setups such as Bipole-Bipole (AM-BN), Dipole-Dipole (AB-MN), and Pole-Tripole (A-BMN) are all suitable for this invention. After acquiring potential data for all electrode combinations using the preset observation device, the cable and electrode positions are moved to begin the next stage of data acquisition.

[0024] As an alternative implementation, once both cables have reached their lowest points and all data collection is complete, a motor-driven reel is used to lift the cables to the ground. The data can then be transmitted from the electrical resistivity meter's main unit to a computer terminal such as a laptop, where it can be processed using a sliding window inversion program.

[0025] As an alternative implementation, the sliding window length is typically set to the maximum distance between the electrodes on the cable, i.e., the distance between the top and bottom electrodes. The detection area can be divided equally according to the window size; if the bottom layer is smaller than a window, it can overlap with the layer above.

[0026] As an alternative implementation, the window increases in size by 2-4 times each time, eventually covering the entire area.

[0027] As an alternative implementation, potential data where electrodes are all located within the windowed detection regions are used for inversion. As the window size increases, more data is used for each region. When the window size expands to cover the entire detection region, all data is used for inversion.

[0028] As an alternative implementation method, there are several options for the inversion method of a single region after grouping. These include the most commonly used smooth-constrained least squares inversion, or the damped least squares method, or using the resistivity range determined by borehole coring as a priori condition and employing an inequality-constrained inversion method, or incorporating other geophysical information (such as radar or seismic interfaces) for joint inversion. The key feature of this invention is its layer-by-layer inversion, with the region gradually increasing. The inversion results of the previous small region are used as the initial model for the next large region, and more observational data are used in the larger region. Parallel processing of multiple small regions can improve the inversion solution speed, and providing an initial model (small region inversion results) for the large region can reduce false anomalies in the inversion.

[0029] As an alternative implementation method, the inversion results can be geologically interpreted in conjunction with borehole data.

[0030] As an alternative implementation method, borehole data can be compared with the borehole resistivity values ​​in the inversion result map to estimate the statistical relationship between resistivity values ​​and geology. Using this statistical relationship and previous geological exploration data, the entire resistivity map can be interpreted into a geological model.

[0031] According to a second aspect of the present invention, the present invention also provides a sliding window inversion system based on transpore resistivity CT, which can fully acquire and quickly invert deep hole data and effectively improve the inversion imaging effect.

[0032] A sliding window inversion system based on transpore resistivity CT includes:

[0033] The data acquisition module is configured in the main unit of the electrical resistivity meter and is used to control the electrodes to acquire data according to the rules of the observation device.

[0034] The lifting module is configured in the main unit of the electrical resistivity meter to control the lifting equipment to move the cable in a regular manner;

[0035] The positioning module is configured on the guide ranging pulley to record the position of the electrode;

[0036] The forward modeling network module, implemented using the finite element method / finite difference method / finite volume method, can calculate the observation data corresponding to the resistivity model, which is then used for inversion.

[0037] The sliding window inversion module is configured to use the collected data to generate the final resistivity model, and to perform layer-by-layer inversion using the small window inversion results as the initial model for the large window inversion.

[0038] The mapping module allows you to input borehole data and the inverted resistivity model to generate resistivity profiles and geological profiles.

[0039] According to a third aspect of the invention, the invention also provides a computer-readable storage medium storing a plurality of instructions adapted for loading by a processor of a terminal device and executing the steps in the method.

[0040] According to a fourth aspect of the present invention, a terminal device is also provided, comprising a processor and a computer-readable storage medium, the processor being configured to implement various instructions; the computer-readable storage medium being configured to store a plurality of instructions adapted to be loaded by the processor and executed in accordance with the steps of the method described therein.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] This invention addresses the challenge of insufficient data acquisition in deep boreholes by designing a trans-hole resistivity CT data acquisition device suitable for deep boreholes. The device can automatically wind and unwind cables according to certain rules and record electrode positions, thereby fully acquiring effective information from the entire deep borehole through the main unit of the electrical resistivity meter.

[0043] This invention addresses the challenge of accurate inversion of deep borehole data by proposing a sliding window inversion method based on transpore resistivity CT. The method groups the acquired data according to spatial location, uses a sliding window to divide the detection area into blocks for inversion, and controls the movement and zoom of the window. Previous inversion results are used as the initial model for a new round of inversion, inverting layer by layer from small to large areas, gradually using more observation data. As the window expands layer by layer, it covers the entire detection area. Compared with conventional methods, this invention can obtain inversion results more quickly and improves the inversion imaging effect of deep borehole data. Attached Figure Description

[0044] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0045] Figure 1 The flowchart shows a sliding window inversion method based on transpore resistivity CT proposed in this invention.

[0046] Figure 2 A schematic diagram of the trans-hole resistivity CT data acquisition device designed for deep holes according to the present invention;

[0047] Figure 3This is a schematic diagram of the sliding window inversion based on transpore resistivity CT proposed in this invention;

[0048] Figure 4a and Figure 4b These are, respectively, the geoelectric model design drawing used in the numerical simulation of the embodiments of the present invention and the imaging results obtained according to the sliding window inversion method;

[0049] Numbered in the diagram: 1. Guide distance measuring pulley, 2. Notebook, 3. Electrical resistivity meter main unit, 4. Battery, 5. Cable, 6. Tripod, 7. Ground, 8. Electrode, 9. Cable reel, 10. Probe hole, 11. Initial value of sliding window, 12. Window after first enlargement, 13. Window covering the entire area, 14. All positions traversed by the electrode, 15. Low-resistivity anomaly. Implementation

[0050] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0051] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0052] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0053] This embodiment discloses a sliding window inversion method based on transpore resistivity CT, such as... Figure 1 As shown, it includes the following steps:

[0054] Step S1: Determine the exploration area based on the results of the preliminary geological survey;

[0055] Step S2, as follows Figure 2 As shown, a tripod 6 and a guide ranging pulley 1 are installed above the two detection holes 10. The cable 5 passes around the guide ranging pulley 1, with one end lowered into the hole and the other end connected to the main unit 3 of the electrical resistivity meter via the winding wheel 9. The main unit of the electrical resistivity meter is powered by a storage battery 4.

[0056] In this embodiment, 21 electrodes are installed on a single cable with a spacing of 1m between them, for numerical simulation to collect potential data.

[0057] Step S3, the initial state of data acquisition is as follows: Figure 2 As shown in (a), all electrodes 8 are placed below the water level. After the main unit 3 of the electrical resistivity meter records the initial position of the electrodes, it collects potential data according to the preset observation device. In this embodiment, the preset observation device is Bipole-Bipole.

[0058] Step S4: After collecting data on the current electrode position, continue lowering one side of cable 5 until all electrodes are below the previous lowest position. Record the current electrode position and collect data according to the preset observation device.

[0059] Step S5, as follows Figure 2 As shown in (b), after one side of cable 5 is placed at its lowest point and data is collected, it is raised to its initial position, and the other side of cable 5 is lowered so that all electrodes on the other side of cable 5 are below their previous lowest position, as shown in (b). Figure 2 As shown in (c), record the current electrode position and collect data according to the preset observation device;

[0060] Step S6, repeat steps S4 and S5 until both cables 5 are at their lowest points and data has been collected. Figure 2 As shown in (d) in the figure, the data acquisition is now complete and the data has been imported into notebook 2;

[0061] Step S7: In this embodiment, the initial length of the sliding window is set to 20m, which is the distance between the top and bottom electrodes on a single cable. Figure 3 As shown in (a), the entire detection area is divided into blocks with an initial sliding window value of 11, and the data of the electrode positions located in a certain area are used for the inversion of that area.

[0062] Step S8: In this embodiment, the window length is doubled, and the detection area is re-divided according to the first enlarged window 12, such as... Figure 3 As shown in (b) above. Using the inversion result of step S7 as the initial model, each window region is inverted independently. This step is repeated, increasing the window size to cover the entire region as shown in Figure 13. Figure 3 As shown in (c);

[0063] The specific geoelectric model in this embodiment is as follows: Figure 4a As shown, the probe depth is 80m and the spacing between probes is 14m. The probe area is set to 16m × 80m, and the background resistivity is 200Ω·m. Six rectangular low-resistivity anomalies 15 are designed in the model, each with a resistivity of 20Ω·m. The electrodes are moved through all positions 14 by moving the cable. After collecting all data, the final resistivity model is obtained using the sliding window inversion method, as shown. Figure 4b As shown.

[0064] Compared to previous deep-hole resistivity detection methods: ① If a method with increased electrode spacing is used for single-acquisition inversion, the electrode spacing needs to be increased by 4m, resulting in a final image resolution of only 2m, greater than the 0.5m resolution in this embodiment; ② If a 1m spacing is used, dividing the detection area into 4 segments, measuring and inverting independently, and then stitching them together, there will be obvious seams at the stitching points. In this embodiment, the resistivity of the entire area transitions smoothly without any stitching marks; ③ If the sliding window inversion method is not used, and all data is inverted at once, the computational load in this embodiment will increase exponentially, i.e., the computation time will increase exponentially. In summary, compared to previous solutions, this invention can fully acquire and quickly invert deep-hole data and effectively improve the inversion imaging effect.

[0065] Furthermore, step S9 can be performed to draw a geological profile map based on the borehole geological data. Since this embodiment is a numerical simulation without relevant geological background, it can only identify the low resistivity area in the inversion results as a geological anomaly area. In actual engineering, geological anomaly areas need to be treated by means of grouting, etc.

[0066] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0067] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0068] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0069] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0071] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A sliding window inversion method based on transpore resistivity CT, characterized in that, Includes the following steps: (1) Determine the detection area according to the engineering requirements, set up a tripod above the two detection holes, and install guide distance measuring pulleys; (2) Set the spatial locations that the electrodes need to traverse and the parameters for cable deployment and retraction; (3) The cable is connected to the main unit of the electrical resistivity meter via the guide distance measuring pulley. The cable is lowered until all electrodes are below the water level, and the initial position of the electrodes is recorded. Data is collected from all electrodes through the main unit of the electrical resistivity meter. (4) Lower the first cable in the first probe hole step by step so that all electrodes on the first cable are lower than the lowest position of the electrodes in the previous stage. Record the position of each stage of electrodes and collect data on the electrodes on the first cable at each stage of electrodes. (5) After the first cable is lowered to the lowest end and data acquisition is completed, it is raised to the initial position, and the second cable in the second probe hole is lowered one level so that all electrodes on the second cable are lower than the lowest position of the electrodes of the previous level. The current electrode position is recorded and data is collected from the electrodes on the second cable. Return to step (4); (6) Repeat steps (4) and (5) until both the first and second cables are placed at the lowest point, the electrodes have traversed all preset positions, and the electrode data at each position has been collected. (7) Set the sliding window size and inversion parameters, divide the entire detection area equally according to the window size, and invert each area independently; (8) Increase the window size, re-divide the detection area, use the previous inversion result as the initial model, invert the new area, and iteratively repeat step (8) until the window covers the entire area; The final resistivity model was obtained and imaged.

2. The sliding window inversion method based on transpore resistivity CT as described in claim 1, characterized in that, The data acquisition equipment consists of two parts: a transpore resistivity CT device and a lifting device; The transpore resistivity CT device includes: a cable with electrodes installed, an electrical resistivity instrument main unit, and a battery; the lifting device includes a tripod, a guide ranging pulley, and a cable reel; the guide ranging pulley is mounted on the tripod; the cable is wound on the cable reel, one end of which is equipped with electrodes is inserted into the detection hole through the guide ranging pulley, and the other end is connected to the electrical resistivity instrument main unit; The cable reel is driven by a motor and can automatically rotate to wind up and unwind the cable after data acquisition is completed, moving the cable and electrode to the next position; The tripod and guide rangefinder pulley are used to record the depth position of the electrode points. By using the initial position of the first electrode, the electrode spacing, and the value of the guide rangefinder pulley, the positions of all electrode points can be derived.

3. The sliding window inversion method based on transpore resistivity CT as described in claim 1, characterized in that, The cable used in transpore resistivity CT equipment is arranged with 20-40 electrodes. The distance between the electrodes is determined by the required detection resolution and is twice the distance of the target resolution.

4. The sliding window inversion method based on transpore resistivity CT as described in claim 1, characterized in that, The main unit of the electrical resistivity meter collects electrode data through a preset observation device, which is a four-electrode device, namely power supply points A and B, and measurement points M and N, both located in the hole. After collecting potential data for all electrode combinations using the preset observation device, the cable and electrode positions are moved to carry out the next stage of data collection.

5. The sliding window inversion method based on transpore resistivity CT as described in claim 1, characterized in that, By moving the first cable and the second cable in sequence, the electrodes traverse all preset positions; the preset positions are spaced apart by the electrode spacing on the cables, filling the entire detection hole.

6. The sliding window inversion method based on transpore resistivity CT as described in claim 1, characterized in that, Sliding window inversion has the following characteristics: The inversion is performed layer by layer, with the area gradually increasing. The inversion results of the previous small area are used as the initial model for the next large area, and more observation data are used in the large area. The initial length of the sliding window is set to the maximum spacing between the electrodes on the cable, i.e., the distance between the top and bottom electrodes; the detection area is divided equally according to the window size, and if the bottom layer area is less than the size of a window, it overlaps with the area above it. The window increases in size by 2-4 times each time, eventually covering the entire area; For the detection areas grouped by window, potential data where all electrodes are located in the area are used for inversion. As the window increases, more data is used for each area. When the window increases to the entire detection area, all data are used for inversion.

7. The sliding window inversion method based on transpore resistivity CT as described in claim 1, characterized in that, After obtaining the final resistivity model and imaging it, the inversion results were geologically interpreted in conjunction with borehole data. In the geological interpretation of the inversion results by combining borehole data, the resistivity values ​​in the borehole data and the inversion result map are compared to estimate the statistical relationship between the resistivity values ​​and geology. Using this statistical relationship and previous geological exploration data, the entire resistivity map can be interpreted into a geological model.

8. A sliding window inversion system based on transpore resistivity CT, comprising: The data acquisition module is configured in the main unit of the electrical resistivity meter and is used to control the electrodes to acquire data according to the rules of the observation device. The lifting module is configured in the main unit of the electrical resistivity meter to control the lifting equipment to move the cable in a regular manner; The positioning module is configured on the guide ranging pulley to record the position of the electrode; The forward modeling network module, implemented using the finite element method / finite difference method / finite volume method, can calculate the observation data corresponding to the resistivity model, which is then used for inversion. The sliding window inversion module is configured to use the collected data to generate the final resistivity model, and to perform inversion layer by layer by using the inversion result of the previous small window as the initial model for the next large window inversion. The mapping module allows you to input borehole data and the inverted resistivity model to generate resistivity profiles and geological profiles.

9. A computer-readable storage medium, characterized in that, It stores multiple instructions adapted for loading by the processor of a terminal device and executing the steps of the method according to any one of claims 1-7.

10. A terminal device, characterized in that, It includes a processor and a computer-readable storage medium, the processor being used to implement various instructions; the computer-readable storage medium being used to store a plurality of instructions adapted to be loaded by the processor and executed in the steps of the method of any one of claims 1-7.

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