Assembly assisting method and device

Abstract

The invention provides an assembly assisting method which comprises the following steps: acquiring data of a product life cycle management system to construct an assembly information base, and determining an assembly process of a to-be-assembled product according to the assembly information base and an assembly task acquired from a manufacturing execution system; scanning all entity parts of the to-be-assembled product to obtain a reconstruction model of each entity part; and matching the assembling process with the reconstruction model of the entity component, and determining and indicating the entity component involved in the assembling step and the assembling method of the entity component before and after the assembling step until the assembling process of the to-be-assembled product is finished.

Description

Assembly auxiliary method and device Technical Field

[0001] The present invention mainly relates to the field of industrial automation, and in particular to an assembly auxiliary method and device. Background Art

[0002] In traditional batch production assembly processes, workers are trained to perform fixed operations corresponding to a limited number of product types. For customized small-batch flexible manufacturing, that is, producing different products on the same production line, workers need to switch between different products. Frequent switching will lead to a higher assembly error rate and lower production efficiency. In order to enable workers to adapt to the new assembly process and improve production efficiency, assembly assistance systems have emerged. One assembly assistance system is based on augmented reality. It identifies the components of the current assembly step by scanning the barcodes attached to the components and provides the corresponding assembly instructions to the workers. However, barcodes need to be attached to the components and assembly instructions need to be prepared manually, so production efficiency is still low. Another assembly assistance system is for specific application scenarios. For example, when tightening screws, augmented reality is used to indicate the position mark of the screws, so that workers can easily tighten the screws. However, it can only be used for specific application scenarios and cannot be applied to other application scenarios.

[0003] Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an assembly assistance method and device to instruct workers to complete assembly tasks, improve production efficiency, and is suitable for various application scenarios.

[0005] To achieve the above-mentioned purpose, the present invention proposes an assembly assistance method, which includes: obtaining data from a product lifecycle management system to construct an assembly information library, determining the assembly process of the product to be assembled based on the assembly information library and the assembly tasks obtained from the manufacturing execution system; scanning all the physical components of the product to be assembled to obtain a reconstructed model of each of the physical components; matching the assembly process with the reconstructed models of the physical components, determining and indicating the physical components involved in the assembly steps and the assembly methods of the previous and next physical components in the assembly steps, until the assembly process of the product to be assembled is completed. To this end, the assembly process of the product to be assembled is determined from data in the product lifecycle management system and the manufacturing execution system, the physical components are scanned to obtain a reconstructed model, and the reconstructed model is matched with the assembly process in real time to instruct the user to complete the assembly according to the assembly process. This process does not require markings to be attached to the physical components, thereby improving production efficiency and being widely applicable to various application scenarios.

[0006] Optionally, indicating the physical components involved in the assembly step includes: projecting light onto the physical components involved in the assembly step by a projector. To this end, projecting light onto the physical components involved in the assembly step by a projector can intuitively indicate the physical components involved to the user.

[0007] Optionally, determining and indicating the physical components involved in an assembly step and the assembly method of the front and rear physical components in the assembly step includes: providing an operation button, and in response to the user pressing the operation button, indicating the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step. To this end, by providing an operation button and indicating the next set of assembly steps in response to the user pressing the operation button, the assembly process can be made more flexible and convenient.

[0008] Optionally, determining and indicating the physical components involved in the assembly step and the assembly method of the front and rear physical components in the assembly step includes providing a human-machine interface device and displaying the assembly method of the front and rear physical components in the assembly step on the human-machine interface device. To this end, by displaying the assembly method of the front and rear physical components in the assembly step on the human-machine interface device, the assembly method in the assembly step can be intuitively indicated to the user.

[0009] Optionally, the method further includes scanning the current physical component after the current assembly step is completed, performing quality verification on the current physical component against a corresponding digital model in the assembly information library, and proceeding to the next assembly step if the quality verification passes. Thus, the assembly quality of the component can be automatically verified in real time, thereby improving production efficiency.

[0010] The present invention also proposes an assembly assistance device, which includes: an acquisition module, which acquires data from the product lifecycle management system to construct an assembly information library, and determines the assembly process of the product to be assembled based on the assembly information library and the assembly tasks obtained from the manufacturing execution system; a modeling module, which scans all the physical components of the product to be assembled and obtains a reconstructed model of each of the physical components; an indication module, which matches the assembly process with the reconstructed model of the physical components, determines and indicates the physical components involved in the assembly steps and the assembly method of the previous and next physical components in the assembly steps, until the assembly process of the product to be assembled is completed.

[0011] Optionally, indicating the physical components involved in the assembly step includes: projecting light onto the physical components involved in the assembly step by a projector.

[0012] Optionally, determining and indicating the physical components involved in an assembly step and the assembly method of the front and rear physical components in the assembly step includes: providing an operation button, and in response to the user pressing the operation button, indicating the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step.

[0013] Optionally, determining and indicating the physical components involved in the assembly step and the assembly method of the front and rear physical components in the assembly step includes: providing a human-machine interface device, and displaying the assembly method of the front and rear physical components in the assembly step on the human-machine interface device.

[0014] Optionally, the device further includes: after the current assembly step is completed, scanning the current physical component, performing quality verification on the current physical component and the corresponding digital model in the assembly information library, and entering the next assembly step when the quality verification passes.

[0015] The present invention also provides an electronic device, comprising a processor, a memory, and instructions stored in the memory, wherein the instructions implement the above-mentioned method when executed by the processor.

[0016] The present invention also provides a computer-readable storage medium having computer instructions stored thereon. When the computer instructions are executed, the method described above is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following drawings are only intended to illustrate and explain the present invention, and do not limit the scope of the present invention.

[0018] FIG1 is a flow chart of an assembly assisting method according to an embodiment of the present invention;

[0019] FIG2 is an exemplary schematic diagram of an implementation process of an assembly assisting method according to an embodiment of the present invention;

[0020] FIG3 is a flow chart of a state machine in an assembly assistance method according to an embodiment of the present invention;

[0021] FIG4 is a schematic diagram of an assembly assisting device according to an embodiment of the present invention;

[0022] FIG5 is a schematic diagram of an electronic device according to an embodiment of the present invention.

[0023] Description of Reference Numerals

[0024] 100 assembly auxiliary methods

[0025] Steps 110-130

[0026] 21Product Lifecycle Management System

[0027] 22 Manufacturing Execution System

[0028] 23Edge computing devices

[0029] 231a Assembly Method Extraction Unit

[0030] 231b instruction generation unit

[0031] 232a Assembly Information Library Building Blocks

[0032] 232b state machine

[0033] 232c operation identification unit

[0034] 233a Component Identification Unit

[0035] 233b search unit

[0036] 233c Digital Model Extraction Unit

[0037] 233d matching unit

[0038] 233e positioning unit

[0039] 233f indicates the generation unit

[0040] 234a Component Identification Unit

[0041] 234b comparison unit

[0042] 24 operation buttons

[0043] 25 projectors

[0044] 26 3D cameras

[0045] Components 27a-27d

[0046] 27e components

[0047] 28 Human-machine interface devices

[0048] Steps 301-314

[0049] 400 assembly auxiliary device

[0050] 410 Get Module

[0051] 420 Modeling Module

[0052] 430 indicator module

[0053] 500 electronic devices

[0054] 510 processor

[0055] 520 memory DETAILED DESCRIPTION

[0056] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0057] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0058] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0059] The present invention provides an assembly assistance method. FIG1 is a flow chart of an assembly assistance method 100 according to an embodiment of the present invention. As shown in FIG1 , the assembly assistance method 100 includes:

[0060] Step 110 , acquiring data from the product lifecycle management system to build an assembly information library, and determining the assembly process of the product to be assembled based on the assembly information library and the assembly tasks acquired from the manufacturing execution system.

[0061] The Product Lifecycle Management (PLM) system integrates product-related information, such as CAD files of various products, assembly methods, resources, etc. The data in the PLM can be obtained through the PLM API to build an assembly information library. The Manufacturing Execution System (MES) provides operators / managers with the execution and tracking of plans and the current status of all resources (people, equipment, materials, customer needs, etc.). The plan can include assembly tasks, that is, the products to be assembled and the quantity of products to be assembled. The assembly tasks are obtained from the MES system. The assembly tasks include the products to be assembled and the quantity of products to be assembled. The products to be assembled are searched in the assembly information library to determine the assembly process of the products to be assembled, that is, the CAD files, assembly methods, assembly tools, etc. of the products to be assembled. For example, the assembly task obtained from the MES system is to assemble a piston. The CAD files, assembly methods, assembly tools, etc. of the piston are searched in the assembly information library. Figure 2 is an exemplary schematic diagram of the implementation process of an assembly assistance method according to an embodiment of the present invention. As shown in Figure 2, the edge computing device 23 includes an assembly information library construction unit 232a. The assembly information library construction unit 232a obtains data from the product lifecycle management system 21 to construct an assembly information library, and determines the assembly process of the product to be assembled based on the assembly information library and the assembly tasks obtained from the manufacturing execution system 22.

[0062] Step 120 : Scan all physical components of the product to be assembled to obtain a reconstructed model of each physical component.

[0063] A 3D sensor can be used to scan all physical components of the product to be assembled. It is understood that all physical components are laid out on a surface without overlapping to avoid mutual interference between the physical components. Modeling the scanned data can obtain a reconstructed model of each physical component. Preferably, the reconstructed model is a point cloud model. As shown in Figure 2, the assembled product is a piston. The piston parts 27a, 27b, 27c, and 27d are laid out on a plane. The 3D sensor 26 scans the piston parts 27a, 27b, 27c, and 27d. The scanned data is sent to the component identification unit 233a. In the component identification unit 233a, the background and noise of the scanned point cloud data are removed, the point cloud corresponding to each component is segmented, and the point cloud data model of each component is reconstructed.

[0064] Step 130 , matching the assembly process with the reconstructed model of the physical components, determining and indicating the physical components involved in the assembly steps and the assembly method of the front and rear physical components in the assembly steps, until the assembly process of the product to be assembled is completed.

[0065] The reconstructed model that matches the assembly process with the physical components can be generated based on the corresponding sample point cloud data of the CAD files of each assembly component, rotated at different angles along the XYZ axis to generate a training data set with the component ID marked, and a deep learning algorithm is used to train the point cloud classification model using the training data set. The point cloud data obtained by scanning the physical component is divided into multiple groups and then filtered to remove noise. Each group of point cloud data is input into the point cloud classification model to predict the corresponding component ID, thereby determining the physical component involved in the assembly step, and indicating the physical component to the user, as well as the assembly method of the previous and next physical components in the assembly step. The user can assemble according to the instructions. After the assembly step is completed, the next assembly step is entered, and the physical components and assembly methods involved continue to be indicated in the next assembly step. The user continues to assemble according to the instructions until the assembly process of the product to be assembled is completed.

[0066] As shown in Figure 2, the component search unit 233b searches for the component currently involved in the assembly process. The digital model extraction unit 233c extracts the CAD model of the component from the assembly information library. The matching unit 233d matches the CAD model of the component with the reconstructed models of all physical components. This determines the ID of the physical component involved in the current assembly step. The component positioning unit 233e then determines the position of the physical component. Finally, the instruction generation unit 233f indicates the position of the physical component. Simultaneously, the assembly method extraction unit 231a extracts the assembly method from the assembly information library. The instruction generation unit 231b generates operation instructions based on the extracted assembly method, instructing the user to perform assembly according to the operation instructions.

[0067] In some embodiments, indicating the physical components involved in the assembly step includes: projecting light onto the physical components involved in the assembly step using a projector. Specifically, as shown in FIG2 , instruction generation unit 233f transmits the component location to projector 25 , which then projects light onto the physical component at the target location based on the component location. In FIG2 , the physical component involved is 27b , and projector 25 projects light onto physical component 27b . Therefore, by projecting light onto the physical components involved in the assembly step, the user can intuitively be informed of the physical components involved.

[0068] In some embodiments, determining and indicating the physical components involved in an assembly step and the assembly method of the front and rear physical components in the assembly step includes: providing an operation button, and in response to the user pressing the operation button, indicating the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step. Specifically, as shown in Figure 2, an operation button 24 is provided. After the user finds the physical components involved according to the instructions and completes the assembly according to the assembly method, the user presses the operation button 24, and the system indicates the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step. To this end, by providing an operation button and indicating the next set of assembly steps in response to the user pressing the operation button, the assembly process can be made more flexible and convenient.

[0069] In some embodiments, determining and indicating the physical components involved in an assembly step and the assembly method of the front and rear physical components in the assembly step includes providing a human-machine interface device and displaying the assembly method of the front and rear physical components in the assembly step on the human-machine interface device. Specifically, as shown in FIG2 , a human-machine interface device 28 is provided, and the assembly method of the front and rear physical components in the assembly step is displayed on the human-machine interface device 28, so that the user can assemble the front and rear physical components in the assembly step according to the assembly method displayed on the human-machine interface device 28. To this end, by displaying the assembly method of the front and rear physical components in the assembly step on the human-machine interface device, the assembly method in the assembly step can be intuitively indicated to the user.

[0070] In some embodiments, the method further includes: after the current assembly step is completed, scanning the current physical component, performing quality verification on the current physical component and the corresponding digital model in the assembly information library, and proceeding to the next assembly step if the quality verification passes. Specifically, as shown in FIG2 , component 27e is a real-time assembly result. After the current assembly step is completed, the current physical component 27e is scanned, the component identification unit 234a reconstructs and identifies the component 27e, and the comparison unit 234b compares the reconstructed identification model of the physical component 27e with the CAD model in the assembly information library, i.e., performing quality verification on the current physical component and the corresponding digital model in the assembly information library, and proceeding to the next assembly step if the quality verification passes.

[0071] The edge computing device 23 also includes a state machine 232b and an operation recognition unit 232c, which can identify user actions and assembly processes. Figure 3 is a flow chart of a state machine in an assembly assistance method according to one embodiment of the present invention. As shown in Figure 3, the state machine includes:

[0072] Step 301, event of operating button 24;

[0073] Step 302, processing the button signal of the operation button 24;

[0074] Step 303, update assembly steps;

[0075] Step 304, extracting assembly information;

[0076] Step 305, scanning the physical component;

[0077] Step 306, indicating the physical component;

[0078] Step 307, generating an operation instruction and displaying it;

[0079] Step 308, scanning the assembled components;

[0080] Step 309, assembly quality verification;

[0081] Step 310, whether the assembly quality verification is passed, if yes, go to step 311, if not, go to step 312;

[0082] Step 311, checking the assembly process;

[0083] Step 312, reassembly;

[0084] Step 313, whether the assembly is completed, if yes, go to step 314, if not, go to step 302;

[0085] Step 314, end.

[0086] The auxiliary assembly method of the present invention will be described below using a piston as a product to be assembled.

[0087] As shown in Figure 2, data is obtained from the PLM system to build an assembly information library, the product to be assembled is determined to be a piston from the MES system, and the CAD file of the piston is extracted from the assembly information library. The assembly method is to lay the piston parts 27a, 27b, 27c, and 27d flat on a plane, and the 3D sensor 26 scans the piston parts 27a, 27b, 27c, and 27d. The scan data is sent to the component identification unit 233a, and the state machine b determines the current assembly step. The search unit 233b searches for the physical component 27a involved in the current assembly step, and the digital model extraction unit 233c extracts the digital model of the physical component 27a. The matching unit 233d matches the digital model of the physical component 27a in all reconstructed models to obtain the ID of the physical component 27a. The component positioning unit 233e determines the position of the physical component 27a, and the instruction generation unit 233 f generates an indication, and the projector 25 projects light onto component 27a according to the indication. The user finds component 27a according to the projection indication, and then presses the operation button 24 to update the assembly step. The component involved in the assembly step is 27b. The projector 25 projects light onto component 27b, and at the same time, the assembly method of the assembly step is displayed in the human-machine interface device 28. The user finds component 27b according to the projection indication, and assembles component 27b to component 27a according to the assembly method of the assembly step displayed in the human-machine interface device 28. The components of component 27b and component 27a are scanned, and the component identification unit 234a identifies and reconstructs the real-time components. The comparison unit 234b compares the identified and reconstructed model with the digital model in the system for quality verification. After passing the quality verification, the user presses the operation button 24 to update the assembly step, and so on, until the last component 27d is assembled, thereby completing the assembly process of the product to be assembled.

[0088] An embodiment of the present invention provides an assembly assistance method, which determines the assembly process of the product to be assembled from data in the product lifecycle management system and the manufacturing execution system, scans the physical components to obtain a reconstructed model, and matches the reconstructed model with the assembly process in real time to instruct the user to complete the assembly according to the assembly process. This process does not require markings on the physical components, improves production efficiency, and is widely applicable to various application scenarios.

[0089] The present invention further provides an assembly assisting device. FIG4 is a schematic diagram of an assembly assisting device 400 according to an embodiment of the present invention. As shown in FIG4 , the assembly assisting device 400 includes:

[0090] The acquisition module 410 acquires data from the product lifecycle management system to build an assembly information library, and determines the assembly process of the product to be assembled based on the assembly information library and the assembly tasks acquired from the manufacturing execution system.

[0091] The modeling module 420 scans all physical components of the product to be assembled and obtains a reconstructed model of each physical component.

[0092] The instruction module 430 matches the assembly process with the reconstructed model of the physical components, determines and instructs the physical components involved in the assembly steps and the assembly devices of the front and rear physical components in the assembly steps until the assembly process of the product to be assembled is completed.

[0093] In some embodiments, indicating the physical components involved in the assembly step includes projecting light onto the physical components involved in the assembly step via a projector.

[0094] In some embodiments, determining and indicating the physical components involved in an assembly step and the assembly method of the front and rear physical components in the assembly step includes: providing an operation button, and in response to the user pressing the operation button, indicating the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step.

[0095] In some embodiments, determining and indicating the physical components involved in the assembly steps and the assembly method of the front and rear physical components in the assembly steps includes: providing a human-machine interface device and displaying the assembly method of the front and rear physical components in the assembly steps on the human-machine interface device.

[0096] In some embodiments, the device further includes: after the current assembly step is completed, scanning the current physical component, performing quality verification on the current physical component and the corresponding digital model in the assembly information library, and entering the next assembly step when the quality verification passes.

[0097] The present invention also provides an electronic device 500. FIG5 is a schematic diagram of an electronic device 500 according to an embodiment of the present invention. As shown in FIG5 , the electronic device 500 includes a processor 510 and a memory 520. The memory 520 stores instructions, wherein the instructions, when executed by the processor 510, implement the method 100 described above.

[0098] The present invention further provides a computer-readable storage medium having computer instructions stored thereon. When the computer instructions are executed, the method 100 described above is executed.

[0099] Some aspects of the methods and apparatus of the present invention may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks," "modules," "engines," "units," "components," or "systems." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLCs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present invention may be embodied as computer products in one or more computer-readable media, the product including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes, etc.), optical disks (e.g., compact disks (CDs), digital versatile disks (DVDs), etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0100] Flowcharts are used herein to illustrate the operations performed by the methods according to the embodiments of the present application. It should be understood that the preceding operations are not necessarily performed in exact order. Instead, the various steps may be performed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0101] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0102] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An assembly assisting method (100), characterized in that: The assembly assistance method (100) comprises: Acquire data from a product lifecycle management system to construct an assembly information library, and determine an assembly process for a product to be assembled based on the assembly information library and assembly tasks acquired from a manufacturing execution system (110); Scanning all physical components of the product to be assembled to obtain a reconstructed model (120) of each physical component; Matching the assembly process with the reconstructed model of the physical component, determining and indicating the physical components involved in the assembly steps and the assembly method of the front and rear physical components in the assembly steps, until the assembly process of the product to be assembled is completed (130).

2. The assembly assisting method (100) according to claim 1, characterized in that: Indicating the physical components involved in the assembly step includes projecting light onto the physical components involved in the assembly step by a projector.

3. The assembly assisting method (100) according to claim 1 or 2, characterized in that: Determining and indicating the physical components involved in an assembly step and the assembly method of the front and rear physical components in the assembly step includes: providing an operation button, and in response to the user pressing the operation button, indicating the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step.

4. The assembly assisting method (100) according to claim 1, characterized in that: Determining and indicating the physical components involved in the assembly steps and the assembly method of the front and rear physical components in the assembly steps includes: providing a human-machine interface device and displaying the assembly method of the front and rear physical components in the assembly steps on the human-machine interface device.

5. The assembly assisting method (100) according to claim 1, characterized in that: The method (100) further includes: after the current assembly step is completed, scanning the current physical component, performing quality verification on the current physical component and the corresponding digital model in the assembly information library, and entering the next assembly step when the quality verification passes.

6. An assembly assisting device (400), characterized in that: The assembly auxiliary device (400) comprises: An acquisition module (410) acquires data from a product lifecycle management system to construct an assembly information library, and determines an assembly process of a product to be assembled based on the assembly information library and assembly tasks acquired from a manufacturing execution system; A modeling module (420) scans all physical components of the product to be assembled to obtain a reconstructed model of each physical component; An instruction module (430) matches the assembly process with the reconstructed model of the physical component, determines and instructs the physical components involved in the assembly steps and the assembly method of the front and rear physical components in the assembly steps until the assembly process of the product to be assembled is completed.

7. The assembly assisting device (400) according to claim 6, characterized in that: The indicating module (430) indicating the physical components involved in the assembly step includes: projecting light onto the physical components involved in the assembly step through a projector.

8. The assembly assisting device (400) according to claim 6 or 7, characterized in that: The indication module (430) determines and indicates the physical components involved in the assembly step and the assembly method of the front and rear physical components in the assembly step, including: providing an operation button, and in response to the user pressing the operation button, indicating the physical components involved in the next assembly step and the assembly method of the front and rear physical components in the next assembly step.

9. The assembly assisting device (400) according to claim 6, characterized in that: The instruction module (430) determines and indicates the physical components involved in the assembly step and the assembly method of the front and rear physical components in the assembly step, including: providing a human-machine interface device, and displaying the assembly method of the front and rear physical components in the assembly step on the human-machine interface device.

10. The assembly assisting device (400) according to claim 6, characterized in that: The device (400) further comprises: after the current assembly step is completed, scanning the current physical component, performing quality verification on the current physical component and the corresponding digital model in the assembly information library, and entering the next assembly step when the quality verification passes.

11. An electronic device (500), comprising a processor (510), a memory (520), and instructions stored in the memory (520), wherein the instructions, when executed by the processor (510), implement the method according to any one of claims 1 to 5.

12. A computer-readable storage medium having computer instructions stored thereon, wherein the computer instructions, when executed, perform the method according to any one of claims 1 to 5.

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