CN111640316A

CN111640316A - Method and device for determining prompt duration based on artificial intelligence and electronic equipment

Info

Publication number: CN111640316A
Application number: CN202010482155.9A
Authority: CN
Inventors: 侯琛
Original assignee: Tencent Technology Shenzhen Co Ltd
Current assignee: Tencent Technology Shenzhen Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2020-09-08
Anticipated expiration: 2040-05-29
Also published as: CN111640316B

Abstract

The embodiment of the invention provides a method and a device for determining prompt duration based on artificial intelligence and electronic equipment. Wherein, the method comprises the following steps: acquiring a space parameter and a driving state parameter, wherein the space parameter comprises a first distance between a target vehicle and a speed limit sign, and the driving state parameter comprises the current speed, the acceleration and the reaction time of the target vehicle; acquiring the forced speed of each state contained in the speed limit sign; searching a first mandatory speed of the current state of the speed limit sign in the mandatory speeds of all states contained in the speed limit sign, and determining the remaining time length of the current state of the speed limit sign, wherein the remaining time length is the time period for switching the speed limit sign from the current state to the next state; and determining the prompt time length of the speed limit sign according to the space parameter, the driving state parameter, the remaining time length and the first mandatory speed. By implementing the embodiment of the invention, the prompt duration can be reasonably determined, the resources of a control system are saved, and the safety of public transportation is improved.

Description

Method and device for determining prompt duration based on artificial intelligence and electronic equipment

Technical Field

The invention relates to the technical field of internet, in particular to a method and a device for determining prompt duration based on artificial intelligence and electronic equipment.

Background

In the field of artificial intelligence, the speed limit sign is an important way for maintaining public traffic safety, so that the prompt of the speed limit sign is particularly important, and particularly the prompt duration of the speed limit sign is directly related to user experience, vehicle passing safety and road passing efficiency.

In the prior art, as long as the speed limit sign is arranged in front of a road where a vehicle is located, the vehicle is frequently prompted without considering duration time of the prompting time, if the prompting time is too long, resources of a control system are wasted, driving experience of a driver is not facilitated, and if the prompting time is too short, the prompting effect cannot be achieved, so that how to reasonably determine the prompting time of the speed limit sign is an important problem to be solved urgently at present.

Disclosure of Invention

The embodiment of the invention provides a method and a device for determining prompt duration based on artificial intelligence and electronic equipment, which can reasonably determine the prompt duration, save resources of a control system and improve the safety of public transportation.

The embodiment of the invention provides a method for determining prompt duration based on artificial intelligence, which comprises the following steps:

acquiring a space parameter and a driving state parameter, wherein the space parameter comprises a first distance between a target vehicle and a speed limit sign, and the driving state parameter comprises the current speed, the acceleration and the reaction time of the target vehicle;

acquiring the forced speed of each state contained in the speed limit sign;

searching a first mandatory speed of the current state of the speed limit sign in the mandatory speeds of all states contained in the speed limit sign, and determining the remaining time length of the current state of the speed limit sign, wherein the remaining time length is the time period for switching the speed limit sign from the current state to the next state;

and determining the prompt time length of the speed limit sign according to the space parameter, the driving state parameter, the remaining time length and the first mandatory speed.

The embodiment of the invention provides a device for determining the prompting time length based on artificial intelligence, which has the function of realizing the method for determining the prompting time length based on artificial intelligence. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes:

the system comprises an acquisition module, a speed limit sign and a control module, wherein the acquisition module is used for acquiring space parameters and driving state parameters, the space parameters comprise a first distance between a target vehicle and the speed limit sign, and the driving state parameters comprise the current speed, the acceleration and the reaction time of the target vehicle;

the acquisition module is also used for acquiring the forced speed of each state contained in the speed limit sign;

the processing module is used for searching the first mandatory speed of the current state of the speed limit sign in the mandatory speeds of all states contained in the speed limit sign and determining the residual time length of the current state of the speed limit sign, wherein the residual time length is the time period for switching the speed limit sign from the current state to the next state;

and the determining module is used for determining the prompt time length of the speed limit sign according to the space parameter, the driving state parameter, the remaining time length and the first mandatory speed.

The invention provides electronic equipment, which comprises a processor, input equipment, output equipment and a memory, wherein the processor, the input equipment, the output equipment and the memory are connected with each other, the memory is used for storing a computer program, the computer program comprises program instructions, and the processor is configured to call the program instructions and is used for executing the operation related to the method for determining the prompt duration based on the artificial intelligence.

The embodiment of the invention provides a computer readable storage medium for storing computer program instructions for terminal equipment, which comprises a program for executing the method for determining the prompting time length based on artificial intelligence.

By implementing the embodiment of the invention, the electronic equipment dynamically adjusts the duration time of the early warning prompt, namely the prompt duration time, by combining the historical congestion rate and the traffic accident rate of the speed-limiting road section where the speed-limiting sign is located, and specifically, the electronic equipment corrects the forced speed of the target vehicle when the target vehicle passes through the speed-limiting sign by the historical congestion rate and the traffic accident rate, and finally reasonably determines the prompt duration time by combining the corrected forced speed, so that the safety of the vehicle passing through the speed-limiting sign is ensured, the resource waste of a control system is reduced, and the safety of public traffic is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a system architecture diagram according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a traffic light monitoring system according to an embodiment of the present invention;

fig. 3 is a schematic flowchart of a method for determining a prompt duration based on artificial intelligence according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a framework for determining a speed limit sign information prompt according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating another method for determining a prompt duration based on artificial intelligence according to an embodiment of the present invention;

fig. 6 is a schematic diagram of another framework for determining information prompt of a speed limit sign according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of an apparatus for determining a prompt duration based on artificial intelligence according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Artificial Intelligence (AI) is a theory, method, technique and application system that uses a digital computer or a machine controlled by a digital computer to simulate, extend and expand human Intelligence, perceive the environment, acquire knowledge and use the knowledge to obtain the best results. In other words, artificial intelligence is a comprehensive technique of computer science that attempts to understand the essence of intelligence and produce a new intelligent machine that can react in a manner similar to human intelligence. Artificial intelligence is the research of the design principle and the realization method of various intelligent machines, so that the machines have the functions of perception, reasoning and decision making.

The artificial intelligence technology is a comprehensive subject and relates to the field of extensive technology, namely the technology of a hardware level and the technology of a software level. The artificial intelligence infrastructure generally includes technologies such as sensors, dedicated artificial intelligence chips, cloud computing, distributed storage, big data processing technologies, operation/interaction systems, mechatronics, and the like. The artificial intelligence software technology mainly comprises a computer vision technology, a voice processing technology, a natural language processing technology, machine learning/deep learning and the like.

With the research and progress of artificial intelligence technology, the artificial intelligence technology is developed and researched in a plurality of fields, such as common smart homes, smart wearable devices, virtual assistants, smart speakers, smart marketing, unmanned driving, automatic driving, safe assistant driving, smart travel, smart roads, unmanned aerial vehicles, robots, smart medical services, smart customer service and the like. The scheme provided by the embodiment of the application mainly relates to the technologies related to artificial intelligence safety-assisted driving, intelligent travel and intelligent roads, and is specifically explained by the following embodiments.

In the field of artificial intelligence, the speed limit sign is an important way for maintaining public traffic safety, so that the prompt of the speed limit sign is particularly important, and particularly the prompt duration of the speed limit sign is directly related to user experience, vehicle passing safety and road passing efficiency. In the prior art, as long as the speed limit sign is located in front of a road where a vehicle is located, the vehicle is frequently prompted without considering duration of the prompting time, if the prompting time is too long, resources of a control system are wasted and driving experience of a driver is not facilitated, and if the prompting time is too short, a prompting effect cannot be achieved, so that the embodiment of the invention provides a method for determining the prompting time based on artificial intelligence, which specifically comprises the following steps: acquiring a space parameter and a driving state parameter, wherein the space parameter comprises a first distance between a target vehicle and a speed limit sign, and the driving state parameter comprises the current speed, the acceleration and the reaction time of the target vehicle; acquiring the forced speed of each state contained in the speed limit sign; searching a first mandatory speed of the current state of the speed limit sign in the mandatory speeds of all states contained in the speed limit sign, and determining the remaining time length of the current state of the speed limit sign, wherein the remaining time length is the time period for switching the speed limit sign from the current state to the next state; and determining the prompt time length of the speed limit sign according to the space parameter, the driving state parameter, the remaining time length and the first mandatory speed. The method provided by the embodiment of the invention can reasonably determine the prompt duration of the speed limit sign, save the resources of a control system and improve the safety of public transportation.

In order to better understand the method for determining the artificial intelligence-based prompt duration provided by the embodiment of the present invention, a system architecture diagram applicable to the embodiment of the present invention is described below.

Referring to fig. 1, fig. 1 is a schematic diagram of a system architecture according to an embodiment of the present invention. As shown in fig. 1, the system architecture diagram includes: a traffic management cloud platform 110, a vehicle 120, and a speed limit sign 130.

The traffic management cloud platform 110 stores state information of a speed limit sign of the speed limit road segment, where the state information includes: at least one state, a duration of each state, and an initial forcing speed of each state. The traffic management cloud platform 110 further stores parameters such as historical congestion rate and historical traffic accident rate of the speed-limited road section.

The vehicle 120 may obtain, from the traffic management cloud platform 110, the state information included in the speed limit sign of the speed limit road segment where the vehicle 120 is located, and parameters such as the historical congestion rate and the historical traffic accident rate.

The speed limit sign 130 may be a traffic light, for example, the traffic light may be in three states of a red light, a yellow light, and a green light, the speed limit sign 130 may also be a traffic police, for example, a gesture of a traffic police may be used as the state of the speed limit sign 130, and speed limit management is performed on the vehicle 120 according to the gesture made by the traffic police.

In one implementation, the speed limit sign 130 is a traffic light, please refer to fig. 2, and fig. 2 is a schematic structural diagram of a traffic light monitoring system according to an embodiment of the present invention. As shown in fig. 2, in the traffic light monitoring system diagram, the state of the speed limit sign of each speed limit section may be displayed. For example, the speed limit sign of the speed limit road section with the north direction has three states of red light, yellow light and green light, and the state of the speed limit sign of the speed limit road section can be a red light state at the moment; the speed limit sign of the speed limit road section with the western direction has three states of a red light, a yellow light and a green light, and the state of the speed limit sign of the speed limit road section can be a yellow light state; the speed limit sign of the speed limit road section with the south direction has three states of a red light, a yellow light and a green light, and the state of the speed limit sign of the speed limit road section can be a green light state at the moment; the speed limit sign of the speed limit road section with the east direction has three states of a red light, a yellow light and a green light, and the state of the speed limit sign of the speed limit road section can be a red light state at the moment.

It should be noted that the invention can be applied to intelligent travel, intelligent roads and safe auxiliary driving. The use scene of the invention is the scene that the vehicle 120 and the speed limit sign 130 need to be informed in advance, namely the conditions need to be met: the speed of the vehicle 120 passing through the speed limit sign 130 can be adjusted to be less than the forced speed of the speed limit sign 130 after being corrected, and particularly, the embodiment of the invention can be embedded into the vehicle, such as an embedded Tencent map and a WeChat small program.

It should be understood that the system architecture diagram described in the embodiment of the present invention is for more clearly illustrating the technical solution of the embodiment of the present invention, and does not constitute a limitation to the technical solution provided in the embodiment of the present invention, and as a person of ordinary skill in the art knows that along with the evolution of the system architecture and the appearance of a new service scenario, the technical solution provided in the embodiment of the present invention is also applicable to similar technical problems.

Referring to fig. 3, fig. 3 is a flowchart illustrating a method for determining a prompt duration based on artificial intelligence according to an embodiment of the present invention. The method may be performed by an electronic device, and includes, but is not limited to, the following steps S310 to S340:

step S310: the electronic equipment acquires a space parameter and a driving state parameter, wherein the space parameter comprises a first distance between the target vehicle and the speed limit sign, and the driving state parameter comprises the current speed, the acceleration and the reaction time of the target vehicle.

The electronic equipment can be a cloud server, and is specifically realized in a way that after the cloud server determines the prompt duration, the prompt duration is sent to a vehicle; the electronic device may also be a vehicle-mounted device installed inside the vehicle, for example, the vehicle-mounted device may be a vehicle-mounted computer, and the specific implementation is that the vehicle may obtain the speed limit sign information from the server first and then determine the prompt duration by itself, which is not limited in the present invention, and the following specific explanation is given by taking the electronic device as the vehicle-mounted computer as an example.

In one implementation, the electronic device obtains the first distance between the target vehicle and the speed limit sign by: the electronic equipment obtains a Global Positioning System (GPS) of the speed limit sign from the traffic management cloud platform, obtains the GPS of the target vehicle, and is calculated according to the obtained GPS of the speed limit sign and the GPS of the target vehicle to obtain a first distance between the target vehicle and the speed limit sign. The method for calculating the first distance by the electronic device according to the GPS of the speed limit sign and the GPS of the target vehicle may specifically be that the electronic device determines the longitude and latitude of the speed limit sign and the longitude and latitude of the target vehicle by acquiring the GPS of the speed limit sign and the GPS of the target vehicle, and then calculates the first distance between the speed limit sign and the target vehicle by using a Java code or a longitude and latitude calculation formula.

For example, assuming that the Longitude and Latitude of the target vehicle are (LonA, LatA), the Longitude and Latitude of the speed limit sign are (LonB, LatB), the east Longitude takes a positive Longitude value (Longitude), the west Longitude takes a negative Longitude value (Longitude), the north Latitude takes a 90-Latitude value (90-Latitude), and the south Latitude takes a 90+ Latitude value (90+ Latitude), the coordinates of the target vehicle and the speed limit sign after the processing are respectively (MLonA, mlataa) and (MLonB, MLatB). Then, according to the triangular derivation, the first distance between the speed limit sign and the target vehicle can be obtained:

C＝sin(MLatA)*sin(MLatB)*cos(MLonA-MLonB)+cos(MLatA)*cos(MLatB)

Distance＝R*Arccos(C)*Pi/180

in one implementation, the electronic device may directly measure a first distance between the target vehicle and the speed limit sign through a high-power infrared device within the target vehicle. The infrared device may be a laser range finder, an infrared range finder, an ultrasonic range finder, or the like, and the present invention is not limited thereto. In specific implementation, the time when the infrared device emits infrared rays is recorded as t1, the time when the infrared device receives infrared rays refracted back by the speed limit sign is recorded as t2, and the electronic device calculates the first distance between the target vehicle and the speed limit sign according to the time t1 and t2, the light speed c being 299792458m/s and the atmospheric refractive index n.

In one implementation, the electronic device obtaining the reaction time of the driver in the target vehicle may be performed by: the electronic equipment carries out face recognition on the driver through a face recognition system in the target vehicle to obtain the class of the driver, and the electronic equipment compares the class of the driver in a preset database to determine the reaction time of the driver in the target vehicle. The preset database can be a traffic management database, and historical statistics of the reaction time of the drivers in each category in the preset categories are stored in the traffic management database.

For example, assume that the predetermined categories are young men, young women, middle-aged men, middle-aged women, etc. The definition of "young" and "middle age" may be adjusted regularly, for example, the age stage is 18 to 30, may be defined as "young", the age stage is 30 to 45, may be defined as "middle age", and the present invention is not limited herein.

In an implementation, the driver may be further divided more finely according to a preset category of the driver, and specifically, the driver in the category of "young men" may be further divided into "professional male driver" and "non-professional male driver"; drivers in the category of "young women" are further classified as "professional female drivers" and "non-professional female drivers", and the present invention is not limited thereto. The definition of "professional driver" and "non-professional driver" may be that the driver who has registered in the relevant public transportation professional platform and has the relevant certificate of authority is a professional driver, and specifically may be a taxi driver, a bus driver, and the like. For example, the electronic device recognizes that the category of the driver in the target vehicle is "professional man driver" through the face recognition system of the vehicle-mounted device, searches the historical statistical value of the reaction time corresponding to the "professional man driver" in the traffic management database, and if the historical statistical value is 0.5s, the electronic device determines that the reaction time of the driver in the target vehicle is 0.5 s.

In one implementation mode, the data stored in the preset database can be updated periodically, specifically, historical statistics values of the reaction time corresponding to each category in the traffic management database are updated according to the pedestrian volume and the traffic volume of the road where the speed limit sign is located.

Step S320: the electronic equipment acquires the forced speed of each state contained in the speed limit sign.

In one implementation mode, the electronic equipment acquires the state information of the speed limit sign, wherein the state information comprises at least one state contained in the speed limit sign, the duration of each state and the initial mandatory speed of each state.

For example, the electronic device obtains the state information of the traffic light of the speed-limited road segment where the target vehicle is located from the traffic management cloud platform. Suppose there are n states, respectively denoted as s₁,s₂,...,s_nThe longest duration of time that they last is recorded as d₁,d₂,...,d_nLet us note that their respective degrees of restriction to the vehicle are w₁,w₂,...,w_nSatisfy w₁≥w₂≥...≥w_n(ii) a The greater the degree of restriction on the vehicle means that the vehicle must travel at a lower speed through the speed-restricted section in this state. For example, if the speed limit sign is a traffic light, it has 3 states: red, yellow, green. Wherein the red limit is the highest and the vehicle must be stopped, i.e. the vehicle speed is 0; the yellow limit degree is moderate, and the vehicle can be ignited and started; the green limit degree is the lowest, and the vehicle can pass through the speed-limiting road section according to the original speed. The electronic equipment is acquired from the traffic management cloud platform at w₁,w₂,...,w_nV is respectively recorded as the initial forced speed of the vehicle when the vehicle reaches the lower part of the speed limit sign₁,v₂,...,v_n. For example, if the speed limit sign is a traffic light and it is in a red light state, the speed of the vehicle when it reaches under the speed limit sign must be 0.

In one implementation, the electronic device corrects the initial forcible speed of each state according to the correction factor to obtain the forcible speed of each state.

For example, if the traffic congestion is more severe and the historical traffic accident rate is higher, the speed of the vehicle when arriving under the speed limit sign is not only the speed that the speed limit sign enforces, i.e., the initial enforced speed, but is related to the congestion situation and the historical accident rate. Specifically, the more severe the congestion is, the higher the historical accident rate is, and the lower the speed of the vehicle when the vehicle reaches below the speed limit sign is. Therefore, the smaller the initial forcible speed of the vehicle when it reaches under the speed limit sign should be. Electronic deviceCorrecting the initial forced speed of each state according to the correction factor to obtain the forced speed v of each state₁/(1+p₁)(1+p₂),v₂/(1+p₁)(1+p₂),...,v_n/(1+p₁)(1+p₂) Wherein 1/(1+ p)₁)(1+p₂) Is a correction factor.

In one implementation mode, the electronic device corrects the initial mandatory speed of each state according to a correction factor, before the mandatory speed of each state is obtained, the electronic device obtains a historical traffic jam rate and a historical traffic accident rate of a road where the speed limit sign is located, and the electronic device obtains the correction factor according to the historical traffic jam rate and the historical traffic accident rate.

For example, the electronic device obtains, from the traffic management cloud platform, a historical congestion rate, denoted as p, of a speed-limited road segment ahead of the target vehicle₁The electronic equipment obtains the historical traffic accident rate of the speed-limited road section of the front road where the target vehicle is located from the traffic management cloud platform and records the historical traffic accident rate as p₂(ii) a The electronic equipment is according to p₁And p₂Obtaining a correction factor, wherein the correction factor is p₁And p₂For example, the correction factor may be: 1/(1+ p)₁)(1+p₂) The correction factor can also be

The specific form of the correction factor is not limited herein, as long as it is p₁And p₂The decreasing function of (a).

Step S330: the electronic equipment searches for a first mandatory speed of the current state of the speed limit sign in the mandatory speeds of all states contained in the speed limit sign, and determines the remaining time length of the current state of the speed limit sign, wherein the remaining time length is the time period for switching the speed limit sign from the current state to the next state.

During specific implementation, the electronic device acquires the current state of the speed limit sign from the traffic management cloud platform and how long the state is finished, namely how long the current state can last. E.g. the current of the speed limit signThe state is s_iIt can also last for a time Δ d_i。

Step S340: and the electronic equipment determines the prompt time length of the speed limit sign according to the space parameter, the driving state parameter, the remaining time length and the first mandatory speed.

As shown in fig. 4, fig. 4 is a schematic diagram of a framework for determining a speed limit sign information prompt according to an embodiment of the present invention. The electronic equipment determines an early warning decision of the electronic equipment about the speed limit sign according to parameters such as the historical congestion rate, the historical traffic accident rate, the first distance between the vehicle and the speed limit sign, the driving state parameter of the vehicle, the state information of the speed limit sign, the current state of the speed limit sign and the like, namely the electronic equipment sends a speed limit sign information prompt to a target vehicle, and specifically, the prompt duration of the speed limit sign sent to the target vehicle by the electronic equipment can be used.

In one implementation, the electronic device calculates a first conversion duration according to the driving state parameter and a first mandatory speed, wherein the first conversion duration is used for indicating a time for the target vehicle to convert from the current speed of the target vehicle to the first mandatory speed, and it is required to say that the current speed is greater than the first mandatory speed. And the electronic equipment calculates a second distance according to the running state parameter, the first mandatory speed and the first conversion duration, wherein the second distance is used for indicating the distance traveled by the target vehicle in the first conversion duration.

For example, assume that the current speed of the target vehicle is v, the acceleration is a, and the reaction time is t_responseThe electronic device calculates a change of the target vehicle from the current velocity v of the target vehicle to the first imposed velocity v by the basic equation of motion_i/(1+p₁)(1+p₂) The time taken to obtain the first conversion duration Deltat_i(ii) a Further, the electronic equipment responds to the current speed v, the acceleration a and the reaction time t_responseAnd a first conversion duration Δ t_iCalculating to obtain a second distance Δ L_i。

In one implementation manner, the determining, by the electronic device, the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance, and the first distance includes: if the second distance is smaller than the first distance and the first conversion time length is smaller than the remaining time length, the electronic equipment takes a first difference value between the remaining time length and the first conversion time length as a first time length, and after the target vehicle starts to decelerate from the current speed and the first difference value time length passes, the electronic equipment determines that the prompt time length of the speed limit sign is the first conversion time length.

For example, the electronic device will determine the second distance Δ L_iComparing with the first distance L, and judging the second distance delta L by the electronic equipment if the electronic equipment judges that_iIf the distance is less than the first distance L, the electronic equipment changes the first conversion time length delta t_iAnd the remaining duration deltad_iComparing, if the electronic device judges the first conversion time length delta t_iLess than remaining duration ad_iThen the electronic device will Δ d_i-Δt_iAs the first period of time. I.e. the lapse of deltad from the start of deceleration of the target vehicle by the current speed ν_i-Δt_iAfter the time period, the electronic equipment determines the prompt duration of the speed limit sign as a first conversion duration delta t_iThe electronic equipment prompts the target vehicle, and the prompt information can comprise that the state of the speed limit sign is s_iThe prompt duration is Deltat_i. Specifically, assume Δ L_i＝10，L＝20，Δt_i＝5s，Δd_iWhen the speed limit sign is 10s and the current state of the traffic light is red light, 5s of information prompt is carried out on the target vehicle by the electronic equipment after the target vehicle starts to decelerate, and the prompt information can be that the state of the traffic light of the road ahead is red light.

Referring to fig. 5, fig. 5 is a flowchart illustrating another method for determining a prompt duration based on artificial intelligence according to an embodiment of the present invention. The method may be performed by an electronic device, and includes, but is not limited to, the following steps S510 to S550:

step S510: the electronic equipment acquires a space parameter and a driving state parameter, wherein the space parameter comprises a first distance between the target vehicle and the speed limit sign, and the driving state parameter comprises the current speed, the acceleration and the reaction time of the target vehicle.

Step S520: the electronic equipment acquires the forced speed of each state contained in the speed limit sign.

Step S530: the electronic equipment searches for a first mandatory speed of the current state of the speed limit sign in the mandatory speeds of all states contained in the speed limit sign, and determines the remaining time length of the current state of the speed limit sign, wherein the remaining time length is the time period for switching the speed limit sign from the current state to the next state.

It should be noted that, in the embodiment of the present application, the execution process of steps S510 to S530 may specifically refer to the execution process of steps S310 to S330 in the embodiment described above, and the embodiment of the present invention is not described again.

Step S540: the electronic equipment acquires the state information of the next state of the speed limit sign, wherein the state information of the next state comprises the duration of the next state and a second mandatory speed, and the duration is used for indicating the longest sustainable time period of the next state.

For example, assume that the current velocity of the target vehicle is v, the acceleration is a, and the reaction time isIs t_responseThe electronic device calculates a change of the target vehicle from the current velocity v of the target vehicle to the first imposed velocity v by the basic equation of motion_i/(1+p₁)(1+p₂) The time taken to obtain the first conversion duration Deltat_i(ii) a Further, the electronic equipment responds to the current speed v, the acceleration a and the reaction time t_responseAnd a first conversion duration Δ t_iCalculating to obtain a second distance Δ L_i。

In one implementation manner, the determining, by the electronic device, the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance, and the first distance includes: if the second distance is smaller than the first distance and the first conversion time length is greater than or equal to the remaining time length, the electronic device obtains state information of a next state of the speed limit sign, where the state information of the next state includes a duration of the next state and a second mandatory speed, and it should be noted that the duration is used to indicate a longest sustainable time period of the next state.

For example, the electronic device will determine the second distance Δ L_iComparing with the first distance L, and judging the second distance delta L by the electronic equipment if the electronic equipment judges that_iIf the distance is less than the first distance L, the electronic equipment changes the first conversion time length delta t_iAnd the remaining duration deltad_iComparing, if the electronic device judges the first conversion time length delta t_iGreater than or equal to the remaining duration deltad_iAnd the electronic equipment acquires the state information of the next state of the speed limit sign. I.e. the lapse of deltad from the start of deceleration of the target vehicle by the current speed ν_i-Δt_iAfter the time period, the electronic equipment determines the prompt duration of the speed limit sign as a first conversion duration delta t_iThe electronic equipment prompts the target vehicle, and the prompt information can comprise that the state of the speed limit sign is s_iThe prompt duration is Deltat_i. Specifically, assume Δ L_i＝10，L＝20，Δt_i＝7s，Δd_iWhen the speed limit sign is 5s, the traffic light is used as the speed limit sign, the current state of the traffic light is red light, and the electronic equipment judges that the current speed of the target vehicle can be reduced to the forced speed in the red light state only after 7s is needed by the target vehicle in the current red light stateThe red light state lasts for only 5s, so that the electronic equipment acquires the state information of the next state of the speed limit sign.

As shown in fig. 6, fig. 6 is a schematic diagram of another framework for determining a speed limit sign information prompt according to an embodiment of the present invention. The electronic equipment determines an early warning decision of the electronic equipment about the speed limit sign according to the historical congestion rate, the historical traffic accident rate, the first distance between the vehicle and the speed limit sign, the driving state parameter of the vehicle, the state information of the speed limit sign, the current state of the speed limit sign, the next state of the speed limit sign and other parameters, namely the electronic equipment sends the speed limit sign information prompt to the target vehicle, and specifically, the prompt duration of the speed limit sign sent to the target vehicle by the electronic equipment can be used.

In one implementation, the electronic device calculates a second conversion duration according to the driving state parameter and a second mandatory speed, where the second conversion duration is used to indicate a time for the target vehicle to convert from the current speed of the target vehicle to the second mandatory speed, and it is noted that the current speed is greater than the second mandatory speed. And the electronic equipment calculates a third distance according to the running state parameter, the second mandatory speed and the second conversion duration, wherein the third distance is used for indicating the distance traveled by the target vehicle in the second conversion duration.

For example, assume that the current speed of the target vehicle is v, the acceleration is a, and the reaction time is t_responseThe electronic device calculates a change of the target vehicle from the current velocity v of the target vehicle to the second imposed velocity v by the basic equation of motion_j/(1+p₁)(1+p₂) The time taken to obtain the second conversion duration Deltat_j(ii) a Further, the electronic equipment responds to the current speed v, the acceleration a and the reaction time t_responseAnd a second conversion duration Δ t_jAnd calculating to obtain a third distance DeltaL_j。

In one implementation manner, the determining, by the electronic device, the prompt duration of the speed limit sign according to the second conversion duration, the remaining duration, the third distance, and the first distance includes: the electronic equipment acquires a second difference value between the second conversion time length and the residual time length; if the third distance is smaller than the first distance and the second difference is smaller than the duration, the electronic equipment takes a third difference between the duration and the second difference as a second time period; and after the target vehicle starts to decelerate from the current speed and the second difference time period passes, the electronic equipment determines the prompting time length of the speed limit sign as a second conversion time length.

For example, assume Δ L_j＝10，L＝20，Δt_j＝10s，Δd_i＝9s，d_jWhen the speed limit sign is a traffic light for 3s, the electronic equipment judges that the third distance is less than the first distance, namely delta L_j<L, then, the electronic device obtains a second conversion duration Δ t_jAnd the remaining duration deltad_iThe second difference between the first time interval and the second time interval is 1s, the electronic device compares the second difference with the duration, namely the electronic device judges the size between 1s and 3s, the electronic device judges that the second difference is smaller than the duration, the electronic device takes a third difference between the duration 3s and the second difference 1s as a second time interval, namely the second time interval is 2s, the electronic device prompts the target vehicle for 10s of information after 2s of time elapses from the time when the target vehicle starts to decelerate, and the prompt information may be that the state of the front road traffic light is a yellow light state and the duration of the yellow light is 3 s.

In one implementation manner, the determining, by the electronic device, the prompt duration of the speed limit sign according to the second conversion duration, the remaining duration, the third distance, and the first distance includes: the electronic equipment acquires a second difference value between the second conversion time length and the residual time length; if the third distance is smaller than the first distance and the second difference is greater than or equal to the duration, the electronic device obtains state information of a next state of the speed limit sign, where the state information of the next state includes the duration of the next state and a third enforcement speed, and it should be noted that the duration is used to indicate a longest sustainable time period of the next state.

In one implementation, the electronic device calculates a third transition duration according to the driving state parameter and a third forced speed, where the third transition duration is used to indicate a time for the target vehicle to transition from the current speed of the target vehicle to the third forced speed, and it is noted that the current speed is greater than the third forced speed. And the electronic equipment calculates a fourth distance according to the running state parameter, the third forced speed and the third conversion duration, wherein the fourth distance is used for indicating the running distance of the target vehicle in the third conversion duration.

For example, assume that the current speed of the target vehicle is v, the acceleration is a, and the reaction time is t_responseThe electronic device calculates a change of the target vehicle from the current velocity v of the target vehicle to the first imposed velocity v by the basic equation of motion_k/(1+p₁)(1+p₂) The time taken to obtain the third transformation duration Δ t_k(ii) a Further, the electronic equipment responds to the current speed v, the acceleration a and the reaction time t_responseAnd a third conversion duration Δ t_kAnd calculating to obtain a fourth distance DeltaL_k。

In one implementation manner, the determining, by the electronic device, the prompt duration of the speed limit sign according to the third conversion duration, the remaining duration, the duration of the next state, the fourth distance, and the first distance includes: the electronic equipment acquires a sum value between the duration and the remaining duration of the next state, and further acquires a difference value between a fourth conversion duration and the sum value as a fourth difference value; if the fourth distance is smaller than the first distance and the fourth difference is smaller than the duration of the next state, the electronic equipment takes a fifth difference between the duration of the next state and the fourth difference as a third time period; and after the target vehicle starts to decelerate from the current speed and the third difference time period passes, the electronic equipment determines the prompt time length of the speed limit sign as a third conversion time length.

For example, assume Δ L_j＝10，L＝20，Δt_k＝10s，Δd_i＝5s，d_j＝3s，d_kWhen the speed limit sign is a traffic light for 6s, the electronic equipment judges that the third distance is less than the first distance, namely delta L_j<L, then, the electronic device obtains the duration d of the next state_jAnd the remaining duration deltad_iThe sum of the time intervals is 8s, and further, the electronic device obtains the third conversion duration Δ t_kAnd the difference value between the sum value and the sum value is taken as a fourth difference value of 2s, the electronic device compares the fourth difference value with the duration time of the next state, namely the electronic device judges the magnitude between 6s and 2s, the electronic device judges that the fourth difference value is smaller than the duration time of the next state, the electronic device takes a fifth difference value between the duration time of the next state 6s and the fourth difference value 2s as a third time period, namely the third time period is 4s, after 4s from the time when the target vehicle starts to decelerate, the electronic device carries out 10s of information prompt on the target vehicle, and the prompt information can be that the state of the front road traffic light is a green light state, and the duration time of the green light is 6 s.

Note that the present invention provides Δ L in the above-described embodiment_i<L，ΔL_j<L,ΔL_k<If any of the L is not established, it indicates that the target vehicle is very close to the speed limit sign, and the speed of the target vehicle when passing through the speed limit sign is necessarily greater than the forced speed of the corrected speed limit sign, in which case, the scheme cannot be applied. It does not meet the purpose of "early warning" of this scheme: and giving the speed limit sign information to the target vehicle under the condition that the target vehicle is far away from the speed limit sign. That is, the target vehicle running state in the embodiment provided by the present invention needs to satisfy: the speed of the target vehicle when passing through the speed limit sign may be adjusted to be less than the forcible speed of the speed limit sign after the correction.

Further, the simulation experiment was repeated 10 times for the embodiment of the present invention, and the experimental results are shown in table 1, and it can be seen from table 1 that the performance of the prior art is inferior to the performance of the technique provided by the embodiment of the present invention.

TABLE 1 results of the experiment

Order of experiment	Ratio of accuracy of speed limit sign information provided to a vehicle by the present invention to prior art
		First experiment	0.71
Second experiment	0.72
		Third experiment	0.74
Fourth experiment	0.78
		Fifth experiment	0.72
The sixth experiment	0.75
		The seventh experiment	0.77
The eighth experiment	0.73
		The ninth experiment	0.79
The tenth experiment	0.76

By implementing the embodiment of the invention, under the condition that the target vehicle cannot decelerate the current speed to the forced speed of the current state within the remaining time of the current state of the speed limit sign, the electronic equipment reasonably and dynamically adjusts the duration of the early warning prompt, namely the prompt time, by combining the state information of the next state of the speed limit sign, specifically, the electronic equipment determines the prompt time through the state information of the current state of the speed limit sign and the state information of the next state of the speed limit sign, so that the safety of the vehicle passing through the speed limit sign is ensured, the resource waste of a control system is reduced, and the safety of public transportation is improved.

Referring to fig. 7, fig. 7 is a schematic structural diagram of an apparatus for determining a prompt duration based on artificial intelligence according to an embodiment of the present invention. The device for determining artificial intelligence-based prompt duration is used for executing steps executed by the electronic device in the method embodiments corresponding to fig. 3 to fig. 6, and the device for determining artificial intelligence-based prompt duration may include:

the acquiring module 710 is configured to acquire a space parameter and a driving state parameter, where the space parameter includes a first distance between the target vehicle and the speed limit sign, and the driving state parameter includes a current speed, an acceleration, and a reaction time of the target vehicle;

the obtaining module 710 is further configured to obtain the mandatory speed of each state included in the speed limit sign;

the processing module 720 is configured to search for a first mandatory speed of the current state of the speed limit sign from the mandatory speeds of the states included in the speed limit sign, and determine a remaining duration of the speed limit sign in the current state, where the remaining duration is a time period during which the speed limit sign is switched from the current state to a next state;

the determining module 730 is configured to determine a prompt duration of the speed limit sign according to the space parameter, the driving state parameter, the remaining duration, and the first mandatory speed.

In one implementation manner, the apparatus for determining a prompt duration based on artificial intelligence further includes: a calculation module 740.

A calculating module 740, configured to calculate a first conversion duration according to the driving state parameter and a first mandatory speed, where the first conversion duration is used to indicate a time for converting a current speed of the target vehicle to the first mandatory speed, and the current speed is greater than the first mandatory speed;

the calculation module 740 calculates a second distance according to the driving state parameter, the first mandatory speed and the first conversion duration, wherein the second distance is used for indicating the distance traveled by the target vehicle within the first conversion duration;

the determining module 730 determines the prompt time length of the speed limit sign according to the first conversion time length, the remaining time length, the second distance and the first distance.

In one implementation manner, the determining module 730 determines the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance, and the first distance, including:

if the second distance is smaller than the first distance and the first conversion time length is smaller than the remaining time length, taking a first difference value between the remaining time length and the first conversion time length as a first time period;

after the first difference time period elapses since the target vehicle is decelerated from the current speed, the determination module 730 determines the prompt time period of the speed limit sign as the first conversion time period.

In one implementation, the obtaining module 710, the determining module 730, and the calculating module 740 determine the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance, and the first distance, including:

if the second distance is smaller than the first distance and the first conversion duration is greater than or equal to the remaining duration, the obtaining module 710 obtains the state information of the next state of the speed limit sign, where the state information of the next state includes a duration of the next state and a second mandatory speed, and the duration is used to indicate a sustainable longest time period of the next state;

the calculating module 740 calculates a second conversion duration according to the driving state parameter and the second mandatory speed, where the second conversion duration is used to indicate a time for the target vehicle to convert from the current speed of the target vehicle to the second mandatory speed, and the current speed is greater than the second mandatory speed;

the calculating module 740 calculates a third distance according to the driving state parameter, the second mandatory speed and the second conversion duration, wherein the third distance is used for indicating the distance traveled by the target vehicle within the second conversion duration;

the determining module 730 determines the prompt time length of the speed limit sign according to the second conversion time length, the remaining time length, the duration, the third distance and the first distance.

In one implementation manner, the determining module 710, the determining module 730, and the processing module 720 determine the prompt duration of the speed limit sign according to the second conversion duration, the remaining duration, the third distance, and the first distance, including:

the obtaining module 710 obtains a second difference between the second conversion duration and the remaining duration;

if the third distance is smaller than the first distance and the second difference is smaller than the duration, the processing module 720 determines a third difference between the duration and the second difference as a second time period;

after the target vehicle starts to decelerate from the current speed for the second difference time period, the determining module 730 determines the prompt duration of the speed limit sign as the second conversion duration.

In one implementation manner, the obtaining module 710 obtains the mandatory speed of each state included in the speed limit sign, including:

the obtaining module 710 obtains the state information of the speed limit sign, where the state information includes the duration of each state included in the speed limit sign and the initial mandatory speed of each state;

the determining module 730 corrects the initial forcing speed of each state according to the correction factor to obtain the forcing speed of each state.

In one implementation, before the determining module 730 corrects the initial forcible speed of each state according to the correction factor to obtain the forcible speed of each state, the method further includes:

the obtaining module 710 obtains a historical traffic jam rate and a historical traffic accident rate of a road where the speed limit sign is located;

the determination module 730 obtains the correction factor according to the historical traffic jam rate and the historical traffic accident rate.

By implementing the embodiment of the invention, the artificial intelligence-based determination device for the prompting time dynamically adjusts the duration of the early warning prompt by combining the historical congestion rate and the traffic accident rate of the speed-limiting road section where the speed-limiting sign is located, namely the prompting time, and particularly, the artificial intelligence-based determination device for the prompting time corrects the forced speed of the target vehicle when the target vehicle passes through the speed-limiting sign by combining the historical congestion rate and the traffic accident rate, and finally reasonably determines the prompting time by combining the corrected forced speed, so that the safety of the vehicle passing through the speed-limiting sign is ensured, the resource waste of a control system is reduced, and the safety of public traffic is improved.

Referring to fig. 8, fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present invention, the electronic device is configured to perform the steps performed by the electronic device in the method embodiments corresponding to fig. 3 to fig. 6, and the electronic device includes: one or more processors 810; one or more input devices 820, one or more output devices 830, and memory 840. The processor 810, input device 820, output device 830, and memory 840 described above are connected by a bus 850. The memory 820 is used to store a computer program comprising program instructions, the processor 810, the input device 820 is used to execute the program instructions stored by the memory 840 to perform the following operations:

the processor 810 acquires a space parameter and a driving state parameter, wherein the space parameter includes a first distance between the target vehicle and the speed limit sign, and the driving state parameter includes a current speed, an acceleration and a reaction time of the target vehicle;

the input device 820 acquires the forced speed of each state contained in the speed limit sign;

the processor 810 searches for a first mandatory speed of the current state of the speed limit sign from the mandatory speeds of the states included in the speed limit sign, and determines the remaining time length of the current state of the speed limit sign, wherein the remaining time length is a time period for switching the speed limit sign from the current state to the next state;

the input device 820 determines the prompt duration of the speed limit sign according to the space parameter, the driving state parameter, the remaining duration, and the first forcible speed.

In one implementation, the processor 810 determines the prompt duration of the speed limit sign according to the spatial parameter, the driving state parameter, the remaining duration and the first mandatory speed, and includes:

the processor 810 calculates a first conversion duration according to the running state parameter and a first mandatory speed, wherein the first conversion duration is used for indicating the time for converting the current speed of the target vehicle to the first mandatory speed, and the current speed is greater than the first mandatory speed;

the processor 810 calculates a second distance according to the driving state parameter, the first mandatory speed and the first conversion duration, wherein the second distance is used for indicating the distance traveled by the target vehicle within the first conversion duration;

the processor 810 determines the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance and the first distance.

In one implementation, the determining, by the processor 810, the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance, and the first distance includes:

if the second distance is smaller than the first distance and the first conversion duration is smaller than the remaining duration, the processor 810 takes a first difference between the remaining duration and the first conversion duration as a first time period;

after the first difference time period has elapsed since the target vehicle decelerated from the current speed, the processor 810 determines the prompt duration of the speed limit sign as a first conversion duration.

if the second distance is smaller than the first distance and the first conversion time length is greater than or equal to the remaining time length, the input device 820 acquires state information of a next state of the speed limit sign, wherein the state information of the next state comprises a duration of the next state and a second mandatory speed, and the duration is used for indicating a sustainable longest time period of the next state;

the processor 810 calculates a second conversion duration according to the driving state parameter and a second mandatory speed, wherein the second conversion duration is used for indicating the time for converting the current speed of the target vehicle to the second mandatory speed, and the current speed is greater than the second mandatory speed;

the processor 810 calculates a third distance according to the driving state parameter, the second mandatory speed and the second conversion duration, wherein the third distance is used for indicating the distance traveled by the target vehicle within the second conversion duration;

the processor 810 determines the prompt duration of the speed limit sign according to the second conversion duration, the remaining duration, the third distance and the first distance.

In one implementation, the determining, by the processor 810, the prompt duration of the speed limit sign according to the second conversion duration, the remaining duration, the third distance, and the first distance includes:

the input device 820 obtains a second difference between the second conversion duration and the remaining duration;

if the third distance is less than the first distance and the second difference is less than the duration, the processor 810 determines a third difference between the duration and the second difference as a second time period;

after the second difference time period elapses since the target vehicle is decelerated from the current speed, the processor 810 determines the prompt time period of the speed limit sign as a second conversion time period.

In one implementation, the input device 820 obtains the mandatory speed of each state included in the speed limit sign, and comprises:

the input device 820 acquires the state information of the speed limit sign, wherein the state information comprises the duration of each state contained in the speed limit sign and the initial forcible speed of each state;

the processor 810 corrects the initial forcible speed of each state according to the correction factor to obtain the forcible speed of each state.

In one implementation, before the processor 810 corrects the initial forcible speed of each state according to the correction factor to obtain the forcible speed of each state, the method further includes:

the input device 820 acquires the historical traffic jam rate and the historical traffic accident rate of the road where the speed limit sign is located;

the processor 810 derives a correction factor based on the historical traffic congestion rate and the historical traffic accident rate.

The embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, where the computer program includes program instructions, and when the program instructions are executed by a processor, the steps performed by the electronic device in the foregoing embodiments may be performed.

It will be understood by those skilled in the art that all or part of the processes of the methods of the above embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium, and when executed, may include the processes of the embodiments of the method for determining the duration of the artificial intelligence based alert. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

While the invention has been described with reference to a number of embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for determining a prompt duration based on artificial intelligence is characterized by comprising the following steps:

acquiring the forced speed of each state contained in the speed limit sign;

2. The method according to claim 1, wherein the determining the prompt duration of the speed limit sign according to the space parameter, the driving state parameter, the remaining duration and the first mandatory speed comprises:

calculating a first conversion duration according to the running state parameter and a first mandatory speed, wherein the first conversion duration is used for indicating the time for converting the target vehicle from the current speed of the target vehicle to the first mandatory speed, and the current speed is greater than the first mandatory speed;

calculating a second distance according to the running state parameter, the first forced speed and the first conversion duration, wherein the second distance is used for indicating the distance of the target vehicle running in the first conversion duration;

and determining the prompt time length of the speed limit sign according to the first conversion time length, the residual time length, the second distance and the first distance.

3. The method according to claim 2, wherein the determining the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance and the first distance comprises:

and after the target vehicle starts to decelerate from the current speed and the first difference time period passes, determining the prompt time length of the speed limit sign as the first conversion time length.

4. The method according to claim 2, wherein the determining the prompt duration of the speed limit sign according to the first conversion duration, the remaining duration, the second distance and the first distance comprises:

if the second distance is smaller than the first distance and the first conversion time length is greater than or equal to the remaining time length, acquiring state information of a next state of the speed limit sign, wherein the state information of the next state comprises a duration of the next state and a second mandatory speed, and the duration is used for indicating a sustainable longest time period of the next state;

calculating a second conversion duration according to the running state parameter and a second mandatory speed, wherein the second conversion duration is used for indicating the time for converting the current speed of the target vehicle to the second mandatory speed, and the current speed is greater than the second mandatory speed;

calculating a third distance according to the running state parameter, a second mandatory speed and a second conversion duration, wherein the third distance is used for indicating the running distance of the target vehicle in the second conversion duration;

and determining the prompt time length of the speed limit sign according to the second conversion time length, the residual time length, the duration, the third distance and the first distance.

5. The method according to claim 4, wherein the determining the prompt duration of the speed limit sign according to the second conversion duration, the remaining duration, the third distance and the first distance comprises:

acquiring a second difference value between the second conversion time length and the residual time length;

if the third distance is smaller than the first distance and the second difference is smaller than the duration, taking a third difference between the duration and the second difference as a second time period;

and after the target vehicle starts to decelerate from the current speed and the second difference time period passes, determining the prompting time length of the speed limit sign as the second conversion time length.

6. The method according to claim 1, wherein the obtaining of the mandatory speed of each state included in the speed limit sign comprises:

acquiring state information of the speed limit sign, wherein the state information comprises the duration of each state contained in the speed limit sign and the initial forced speed of each state;

and correcting the initial forcible speeds of the states according to the correction factors to obtain the forcible speeds of the states.

7. The method of claim 6, wherein before the step of modifying the initial forcing speed of each state according to a modification factor to obtain the forcing speed of each state, the method further comprises:

acquiring historical traffic jam rate and historical traffic accident rate of a road where the speed limit sign is located;

and obtaining the correction factor according to the historical traffic jam rate and the historical traffic accident rate.

8. An apparatus for determining a duration of a prompt based on artificial intelligence, comprising:

9. An electronic device, comprising a memory and a processor, wherein the memory stores a set of program codes, and the processor calls the program codes stored in the memory to execute any one of operations 1 to 7.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program comprising program instructions which, when executed by a processor, cause the processor to carry out the method according to any one of claims 1 to 7.