Train safety standstill calculation method, apparatus, and medium for tacs systems

Abstract

The application relates to a train safety stationary calculation method, device and medium for a TACS system, which comprises the following steps: S1, a vehicle-mounted controller CC judges whether the train needs to start safety stationary calculation at the moment; S2, the vehicle-mounted controller CC stores current train motion parameters and parameters needed to participate in train safety stationary calculation in the future; S3, the vehicle-mounted controller CC judges whether the stored parameters are valid; S4, the vehicle-mounted controller CC assigns default values to the parameters; S5, the vehicle-mounted controller CC calculates a train stationary time; S6, the vehicle-mounted controller CC compares the current time with the train stationary time calculated in the step S5, and if the current time is greater than the train stationary time, it is judged that the train has been safely stationary, otherwise, the train is not in a safety stationary state. Compared with the prior art, the application has the advantages of improving the safety and reliability in the actual train operation process.

Description

Technical Field

[0001] This invention relates to rail transit signaling systems, and more particularly to a method, device, and medium for calculating train safety stationarity in a TACS system. Background Technology

[0002] Train Autonomous Operation System (TACS) based on vehicle-to-vehicle communication is a key direction for the development of current train control systems. Traditional signaling systems typically rely on the sampling of train braking signals to ensure that the train has come to a safe stop. However, this method cannot guarantee that the train is truly stationary.

[0003] A search of Chinese Patent Publication No. CN109383563A reveals a method, device, and area controller for calculating the safe position of a train. The method includes: determining a calculation scenario for the current safe position of the train; determining a target calculation rule corresponding to the current calculation scenario based on a preset relationship between the scenario and calculation rules; and calculating the current safe position of the train according to the target calculation rule. By selecting an appropriate target calculation rule based on the scenario, the calculated train safe position is made more reliable and accurate. However, this existing patent, while addressing the calculation of the train's safe position, does not address the reliable calculation of the train's stationary state.

[0004] Therefore, how to improve the reliability and safety of train stationary safety calculations has become a technical problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a method, device and medium for calculating the safe stationary position of trains in a TACS system.

[0006] The objective of this invention can be achieved through the following technical solutions: According to a first aspect of the present invention, a method for calculating the safe stationary position of a train in a TACS system is provided, the TACS system including an onboard controller (CC), a trackside controller (WTC), and a resource manager (WRC), the method comprising the following steps: Step S1: The on-board controller CC determines whether the train needs to start the safe stationary calculation. If yes, proceed to step S3; otherwise, proceed to step S2. Step S2: The on-board controller CC stores the current train motion parameters and the parameters that need to be used for the train to remain stationary, and returns to step S1. Step S3: The vehicle controller CC determines whether the stored parameters are valid. If yes, proceed to step S5; otherwise, proceed to step S4. Step S4: The vehicle controller CC assigns default values ​​to the parameters. After completion, step S5 is executed. Step S5: The on-board controller CC calculates the time when the train stops. After the calculation is completed, step S6 is executed. In step S6, the on-board controller CC selects the current time and compares it with the train stationary time calculated in step S5. If the current time is greater than the train stationary time, it is determined that the train has come to a safe stop; otherwise, the train is not in a safe stationary state.

[0007] As a preferred technical solution, the following conditions must be met simultaneously for the safe static calculation to be initiated in step S1: 101) At this time, all motion parameters of the train are in normal condition; 102) The train's safe speed is now below the set threshold; 103) The onboard controller (CC) is no longer sending commands to the train to apply traction; 104) The onboard controller (CC) is no longer sending commands to the train to cancel the brakes.

[0008] As a preferred technical solution, in step 102), the speed is determined by detecting the number of teeth on the train odometer. If the number of teeth remains unchanged, the safe speed is already less than the set threshold.

[0009] As a preferred technical solution, in step 103), if current vital local date > Planned traction authorization end date + Guaranteed traction cut-off delay, then the onboard controller CC will no longer send traction authorization to the train at the current moment. Where current vital local date is the current time, Planned traction authorizationend date is the time when the onboard controller (CC) sends the traction authorization termination message to the train, and Guaranteed traction cut-off delay is the delay required for the actual train to cancel traction.

[0010] As a preferred technical solution, in step 104), if current vital local date > Plannedbraking release end date + Guaranteed braking application delay, then at the current moment, the on-board controller CC will no longer send a braking revocation authorization to the train. Where current vital local date is the current time, Planned braking release enddate is the braking cancellation abort time sent by the onboard controller CC to the train, and Guaranteed braking application delay is the delay required for the actual train to apply braking.

[0011] As a preferred technical solution, the parameters stored in step S2 include: the train's safe average train speed, the train's speed measurement end date, the train's maximum planned acceleration due to gradient, the train's EB deceleration (Worstemergency brake from qualified kinematics), and the train's current traction acceleration (Maximum traction acceleration).

[0012] As a preferred technical solution, the default value assigned in step S4 is set to the safety-oriented side, as follows: Vital average train speed is the maximum permissible operating speed of the train. The end date of the Vital speed measurement is the current time. Maximum planned acceleration due to gradient is the worst-case slope acceleration along the entire line. Worst emergency brake from qualified kinematics; take the train's maximum EB deceleration. Maximum traction acceleration is the maximum traction acceleration of the train.

[0013] As a preferred technical solution, the calculation in step S5 specifically involves: Immobilisation date = Vital speed measurement end date + Delay before traction cut-off + Delay between traction cur-off and braking + Delay to stop Where Immobilisation date is the time the train came to a standstill; "Delay before traction cut-off" refers to the delay before traction is removed. The delay between traction cur-off and braking is the time between traction cancellation and braking application. Delay to stop is the delay required for the train to stop.

[0014] As a preferred technical solution, the specific calculations for Delay before traction cut-off, Delay between traction cut-off and braking, and Delay to stop are as follows: Delay before traction cut-off = max(0, planned traction authorizationend date + Guaranteed traction cut-off delay) Delay between traction cur off and braking = max[0,Planned braking release end date +max(Planned braking release end date +Guaranteed tractioncut-off delay, Vital speed measurement end date)] Delay to stop = -Speed ​​at braking / (Worst emergency brake from qualified kinematics+Maximum planned acceleration due to gradient) where planned traction authorization end date Guaranteed traction cut-off delay is the delay required for the actual train to cancel traction. The Planned braking release end date is the time when the onboard controller CC sends the braking cancellation abort signal to the train. Vital speed measurement end date is the time when train speed measurement ends. Speed ​​at braking is the speed during braking. Worst emergency brake from qualified kinematics is the train's EB deceleration; The maximum planned acceleration due to gradient is the acceleration due to the train's incline.

[0015] As a preferred technical solution, the Speed ​​at braking is specifically calculated as follows: Speed ​​at braking = Speed ​​at traction cut-off +Delay between tractioncur off and braking×Maximum planned acceleration due to gradient; Speed ​​at traction cut-off = Vital average train speed +Delay before traction cut-off×(Maximum traction acceleration + Maximum plannedacceleration due to gradient) Where Speed ​​at traction cut-off is the train speed when braking is applied. The delay between traction, cur off, and braking refers to the speed of the train when traction is withdrawn.

[0016] As a preferred technical solution, the calculation of the train station time is divided into several stages, namely the stage before the train traction is cancelled, the stage before the train traction is cancelled and the stage before the brake is applied, and the stage when the train brake is applied. In the stage before the train traction is removed, the train speed is equal to the initial speed plus the work done by the traction and the acceleration due to the slope during this stage. Before the train traction is released and the brake is applied, the train is in a coasting state. At this time, the train speed is equal to the initial speed plus the work done by the ramp acceleration during this stage. During the train braking phase, the train's speed is equal to the initial speed plus the work done by the EB deceleration and the ramp acceleration during this phase.

[0017] As a preferred technical solution, the train EB deceleration is obtained from the real-time calculation of the track adhesion coefficient by the trackside controller WTC and the resource controller WRC, and then returned to the on-board controller CC.

[0018] According to a second aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described thereon.

[0019] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0020] Compared with the prior art, the present invention has the following advantages: 1) Based on the calculation of train stationary status using train braking signals, this invention redesigns the calculation method for safe train stationary status. Triggered from a time perspective, it determines the relationship between the train's stationary moment and the current moment to ensure the train remains stationary from both the system's movement authorization perspective and the train's actual movement perspective. This improves the safety and reliability of actual train operation. 2) This invention determines whether safe static calculation is required by setting multiple preconditions, thereby avoiding invalid calculations and thus avoiding wasting computing resources; 3) This invention calculates the time when the train is stationary in different stages and uses different calculation methods for each stage, which further improves the calculation accuracy. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the train safety stationary calculation method of the present invention. Figure 2 This is a graph showing the speed versus time at different stages of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] like Figure 1As shown, a method for calculating train safety at rest in a TACS system is presented. The TACS system includes an onboard controller (CC), a trackside controller (WTC), and a resource manager (WRC). The onboard controller (CC) is the primary train controller, assisting the train in requesting various resources on the track during operation. The trackside controller (WTC) is a backup controller, also providing relevant track information to the onboard controller (CC). The resource manager (WRC) is primarily responsible for distributing resources on the operating track to the onboard controller (CC) and the trackside controller (WTC), ensuring the train can successfully obtain movement authorization on the track, thereby improving actual operational efficiency.

[0024] The method includes the following steps: Step 1: The onboard controller (CC) determines whether the train needs to start the safe stationary procedure calculation. If the train does not need to start the calculation program, proceed to Step 2; if the train needs to start the calculation program, proceed to Step 3.

[0025] Step 2: The onboard controller (CC) stores the current train motion parameters and the parameters that need to be used for the train to remain stationary. After completion, it returns to Step 1.

[0026] Step 3: The vehicle controller CC determines whether the stored parameters are valid. If the parameters are invalid, proceed to step 4; if the parameters are valid, proceed to step 5.

[0027] Step 4: The onboard controller (CC) assigns default values ​​to the parameters Vital average train speed, Vital speed measurement end date, Maximum planned acceleration due to gradient, Worstemergency brake from qualified kinematics, and Maximum traction acceleration. After completion, proceed to Step 5.

[0028] Step 5: The onboard controller (CC) calculates the train's stationary time (Immobilization date). Once the calculation is complete, proceed to Step 6. Step Six: The onboard controller (CC) selects the current vital local date and compares it with the Immobilisation date from Step Five. If the current vital local date > Immobilisation date, it is determined that the train has come to a safe stop; otherwise, the train is not in a safe stop state, and the calculation is complete.

[0029] The main method for determining whether a train needs to be safely stationary in step one is as follows: 1. It is necessary to check that all motion status parameters of the train are currently in a normal state. 2. It is necessary to ensure that the train's safe speed is below the threshold at this time, which is mainly achieved by detecting that the number of teeth on the train's odometer no longer changes.

[0030] 3. It is necessary to ensure that the onboard controller (CC) does not send traction commands to the train. This is mainly achieved by checking if the current vital local date is greater than the planned traction authorization end date plus the Guaranteed traction cut-off delay. The current time is greater than the time when the onboard controller (CC) sent the traction authorization to the train to terminate, plus the delay required for the actual train to cancel traction. This ensures that the onboard controller (CC) will not send traction authorization to the train at the current time.

[0031] 4. It is necessary to ensure that the onboard controller (CC) does not send a brake cancellation command to the train. This is mainly achieved by checking if the current vital local date is greater than the planned braking release end date plus the Guaranteedbraking application delay. The current time is greater than the brake cancellation abort time sent by the onboard controller (CC) to the train, plus the delay required for the actual train to apply brakes. This ensures that the onboard controller (CC) will not send a brake cancellation authorization to the train at the current time.

[0032] The parameters that need to be stored in step two mainly include Vital average train speed, Vital speed measurement end date, Maximum planned acceleration due to gradient, Worstemergency brake from qualified kinematics, and Maximum traction acceleration.

[0033] In step two, Vital average train speed is the train's safe average speed, Vital speed measurement end date is the time when the train speed measurement ends, Maximum planned acceleration due to gradient is the train's gradient acceleration, Worst emergency brake from qualified kinematics is the train's EB deceleration, and Maximum traction acceleration is the train's current traction acceleration.

[0034] In step three, if the stored parameters are no longer usable, the correct parameters cannot be used to calculate the train's stationary time. In this case, it is necessary to proceed to step four to use the default parameters for calculation to ensure the safety of the calculation results.

[0035] In step four, the default values ​​are assigned to the safety-oriented side, always selecting the parameters under the worst-case scenario in the system. Vital average train speed is the maximum permissible train speed, Vital speed measurement enddate is the current time, Maximum planned acceleration due to gradient is the worst-case gradient acceleration along the entire line, Worst emergency brake from qualified kinematics is the maximum EB deceleration of the train, and Maximum traction acceleration is the maximum traction acceleration of the train.

[0036] In step five, the onboard controller (CC) calculates the train's stationary time, the Immobilisation date. The specific calculation logic is as follows: Immobilization date = Vital speed measurement end date + Delay before traction cut-off + Delay between traction cur-off and braking + Delay to stop; in Delay before traction cut-off = max(0, planned traction authorizationend date + Guaranteed traction cut-off delay); Delay between traction cur off and braking = max[0,Planned braking release end date +max(Planned braking release end date +Guaranteed tractioncut-off delay, Vital speed measurement end date)]; Delay to stop = -Speed ​​at braking / (Worst emergency brake from qualified kinematics+Maximum planned acceleration due to gradient); Speed ​​at braking = Speed ​​at traction cut-off +Delay between tractioncur off and braking×Maximum planned acceleration due to gradient; Speed ​​at traction cut-off = Vital average train speed + Delay before traction cut-off × (Maximum traction acceleration + Maximum planned acceleration due to gradient).

[0037] Delay before traction cut-off is the delay before traction is cancelled. The delay between traction curoff and braking is the time between traction cancellation and braking application. Delay to stop is the delay required for the train to stop. Speed ​​at braking is the speed of the train when braking is applied. Speed ​​at traction cut-off is the speed of the train when traction is removed. Step five, calculating the train's stationary time, is divided into several stages: the stage before traction cancellation, the stage before braking application (coasting state), and the stage of applying the brakes. In the stage before traction cancellation, the train is still under traction; its speed equals its initial speed plus the work done by traction and ramp acceleration during this stage. In the stage of applying the brakes, the train is in a coasting state; its speed equals its initial speed plus the work done by ramp acceleration during this stage. In the stage of applying the brakes, the train's speed equals its initial speed plus the work done by EB deceleration and ramp acceleration during this stage. By calculating the time for each of these three stages and combining this with the above formula, the actual time the train takes to come to a complete stop can be obtained.

[0038] In step five, the EB deceleration is obtained from the real-time calculation of the track adhesion coefficient by the trackside controller WTC and the resource controller WRC, and then returned to the on-board controller CC.

[0039] In step six, if the current time is greater than the time when the train came to a standstill, it means that from both the system's perspective and the train's perspective, the train is considered to be in a standstill at this point.

[0040] This invention redesigns the calculation method for train safety at rest, triggering it from a time perspective. By judging the relationship between the train's stationary moment and the current moment, it ensures that the train is stationary from both the system's movement authorization perspective and the train's actual movement perspective, thereby improving the safety and reliability of actual train operation.

[0041] The above is an introduction to the method embodiments. The following embodiments using electronic devices and storage media will further illustrate the solution of the present invention.

[0042] This invention also provides an electronic device including a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded from a storage unit into a random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0043] Multiple components in the device are connected to the I / O interface, including: input units such as keyboards and mice; output units such as various types of displays and speakers; storage units such as disks and optical discs; and communication units such as network interface cards (NICs), modems, and wireless transceivers. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0044] The processing unit performs the various methods and processes described above, such as the methods of the present invention. For example, in some embodiments, the methods of the present invention may be implemented as computer software programs tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or a communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of the methods of the present invention described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute the methods of the present invention by any other suitable means (e.g., by means of firmware).

[0045] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0046] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0047] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for calculating train safety stationarity in a TACS system, wherein the TACS system includes an onboard controller (CC), a trackside controller (WTC), and a resource manager (WRC), characterized in that, The method includes the following steps: Step S1: The on-board controller CC determines whether the train needs to start the safe stationary calculation. If yes, proceed to step S3; otherwise, proceed to step S2. Step S2: The on-board controller CC stores the current train motion parameters and the parameters that need to be used for the train to remain stationary, and returns to step S1. Step S3: The vehicle controller CC determines whether the stored parameters are valid. If yes, proceed to step S5; otherwise, proceed to step S4. Step S4: The vehicle controller CC assigns default values ​​to the parameters. After completion, step S5 is executed. Step S5: The on-board controller CC calculates the time when the train stops. After the calculation is completed, step S6 is executed. Step S6: The on-board controller CC selects the current time and compares it with the train station time calculated in step S5. If the current time is greater than the train station time, it is determined that the train has safely stopped; otherwise, the train is not in a safe stationary state. Initiating the safe static calculation in step S1 requires the following conditions to be met simultaneously: 101) At this time, all motion parameters of the train are in normal condition; 102) The train's safe speed is now below the set threshold; 103) The onboard controller (CC) is no longer sending commands to the train to apply traction; 104) The onboard controller (CC) is no longer sending commands to the train to cancel the brakes; The parameters stored in step S2 include: the train's safe average train speed, the train's speed measurement end date, the train's maximum planned acceleration due to gradient, the train's worst emergency brake from qualified kinematics, and the train's current maximum traction acceleration. In step S4, the default value is assigned to the safety side, as follows: Vital average train speed is the maximum permissible operating speed of the train. The end date of the Vital speed measurement is the current time. Maximum planned acceleration due to gradient is the worst-case slope acceleration along the entire line. Worst emergency brake from qualified kinematics; take the train's maximum EB deceleration. Maximum traction acceleration is the maximum traction acceleration of the train. The calculation in step S5 is specifically as follows: Immobilisation date = Vital speed measurement end date + Delay before traction cut-off + Delay between traction cur-off and braking + Delay to stop Where Immobilisation date is the time the train came to a standstill; "Delay before traction cut-off" refers to the delay before traction is removed. The delay between traction cur-off and braking is the time between traction cancellation and braking application. Delay to stop is the delay required for the train to stop. The specific calculations for Delay before traction cut-off, Delay between traction cut-off and braking, and Delay to stop are as follows: Delay before traction cut-off = max(0, planned traction authorization enddate + Guaranteed traction cut-off delay) Delay between traction cur off and braking = max[0,Planned braking release end date +max(Planned braking release end date +Guaranteed tractioncut-off delay, Vital speed measurement end date)] Delay to stop = -Speed ​​at braking / (Worst emergency brake from qualifiedkinematics+Maximum planned acceleration due to gradient) where planned traction authorization end date Guaranteed traction cut-off delay is the delay required for the actual train to cancel traction. The Planned braking release end date is the time when the onboard controller CC sends the braking cancellation abort signal to the train. Vital speed measurement end date is the time when train speed measurement ends. Speed ​​at braking is the speed during braking. Worst emergency brake from qualified kinematics is the train's EB deceleration; The maximum planned acceleration due to gradient is the acceleration due to the train's incline. The specific calculation for Speed ​​at braking is as follows: Speed ​​at braking = Speed ​​at traction cut-off +Delay between traction curoff and braking×Maximum planned acceleration due to gradient; Speed ​​at traction cut-off = Vital average train speed +Delay before traction cut-off×(Maximum traction acceleration + Maximum plannedacceleration due to gradient) Where Speed ​​at traction cut-off is the train speed when braking is applied. The delay between traction, cur off, and braking refers to the speed of the train when traction is withdrawn.

2. The method for calculating train safety at rest in a TACS system according to claim 1, characterized in that, In step 102), the speed is determined by detecting the number of teeth on the train odometer. If the number of teeth remains unchanged, the safe speed is already less than the set threshold.

3. The method for calculating train safety at rest in a TACS system according to claim 1, characterized in that, In step 103), if the current vital local date > Planned traction authorization end date + Guaranteed traction cut-off delay, then the onboard controller CC will no longer send traction authorization to the train at the current moment. Where current vital local date is the current time, Planned traction authorization enddate is the time when the onboard controller (CC) sends the traction authorization termination message to the train, and Guaranteed traction cut-off delay is the delay required for the actual train to cancel traction.

4. The method for calculating train safety at rest in a TACS system according to claim 1, characterized in that, In step 104), if current vital local date > Planned braking release end date + Guaranteed braking application delay, then at the current moment, the onboard controller CC will no longer send a braking revocation authorization to the train. Where current vital local date is the current time, Planned braking release end date is the time when the onboard controller (CC) sends the braking cancellation abort message to the train, and Guaranteed braking application delay is the delay required for the actual train to apply braking.

5. The method for calculating train safety stationarity in a TACS system according to claim 1, characterized in that, The calculation of the train's stationary time is divided into several stages, namely the stage before the train traction is cancelled, the stage before the train traction is cancelled and the stage before the brake is applied, and the stage when the train brake is applied. In the stage before the train traction is removed, the train speed is equal to the initial speed plus the work done by the traction and the acceleration due to the slope during this stage. Before the train traction is released and the brake is applied, the train is in a coasting state. At this time, the train speed is equal to the initial speed plus the work done by the ramp acceleration during this stage. During the train braking phase, the train's speed is equal to the initial speed plus the work done by the EB deceleration and the ramp acceleration during this phase.

6. The method for calculating train safety stationarity in a TACS system according to claim 1, characterized in that, The train's EB deceleration is derived from the real-time calculation of the track adhesion coefficient by the trackside controller WTC and the resource controller WRC, and then returned to the onboard controller CC.

7. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 6.

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