KR20220051738A - Method for calculating road congestion and road congestion calculation device performing method - Google Patents

Abstract

According to an embodiment of the present invention, a method by which a road congestion calculation device calculates the congestion of the road comprises the steps of: obtaining at least one of message subscription information and access information of user terminals located in a first link among a plurality of links obtained by dividing the road according to predetermined criteria; calculating the number of the user terminals located in the first link by using the obtained at least one of the message subscription information and the access information; and calculating the congestion of the first link by using the number of the user terminals located in the first link and obtained road information in the first link. Therefore, the congestion of the road can be calculated more accurately.

Description

A method for calculating a road congestion level and a road congestion level calculation device for performing the method

The present invention relates to a method for calculating a road congestion level and a road congestion level calculation apparatus for performing the method.

BACKGROUND ART A navigation device is a device installed in a vehicle to guide a road, and is currently widely used to find a route to a destination faster and more accurately while driving the vehicle.

A navigation application that performs navigation for a vehicle receives GPS location information from a GPS satellite, specifies the location of the vehicle on a pre-stored map, and determines the location of the vehicle using changes in GPS location information and relative changes in the location of the vehicle. It works by updating.

Meanwhile, in order for a navigation application to provide an optimal route to a vehicle, it is essential to understand the congestion level of the road, that is, the amount of vehicle traffic on the road.

However, with a general navigation application, it is possible to obtain only the driving information of each vehicle, and it is difficult to obtain the driving information of the entire vehicle on the road, and a separate device may be required to acquire the driving information of the entire vehicle on the road. A method of calculating the road congestion level with only the navigation application without investment in other facilities may be problematic.

The problem to be solved by the present invention is to calculate the congestion level of the road where the user terminal is located by using the message subscription information and access information of the user terminal obtained through a message broker communicating with the MQTT protocol in order to solve the above problem. to provide a way

However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems to be solved that are not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

In the method for calculating the congestion level of a road by an apparatus for calculating road congestion according to an embodiment of the present invention, message subscription information and access information of a user terminal located in a first link among a plurality of links dividing the road based on a predetermined criterion obtaining at least one of calculating the number of user terminals located in the first link by using at least one obtained from the message subscription information and the access information; and calculating the congestion level of the first link by using the number of the user terminals located in the first link and previously obtained road information of the first link.

The step of obtaining at least one of the message subscription information and the access information includes receiving at least one of the message subscription information and the access information from a message broker that communicates with the user terminal using a Message Queue Telemetry Transport (MQTT) protocol, The message subscription information may be generated based on a message subscription request or message subscription cancellation, which the user terminal applies to the message broker using the first link as a topic.

The road information may include at least one of a length of the first link, a road class, a speed limit, and the number of lanes.

The step of calculating the number of user terminals located in the first link includes the number of user terminals that have applied for message subscription, the number of user terminals that have applied for message cancellation, and access to a message broker communicating with the user terminal using the MQTT protocol Using the number of terminated user terminals, the number of user terminals located in the first link may be calculated.

The calculating of the congestion degree of the first link may include: calculating a preset weight on the number of the user terminals located in the first link to determine the number of vehicles located in the first link; and calculating the congestion level of the first link by using the number of vehicles located in the first link and road information of the first link.

A road congestion calculation apparatus according to another embodiment of the present invention includes: a transceiver for acquiring at least one of message subscription information and access information of a user terminal located in a first link among a plurality of links dividing a road based on a predetermined criterion; and calculating the number of user terminals located in the first link by using at least one obtained from the message subscription information and the access information, and calculating the number of user terminals located in the first link and the obtained first The processor may include a processor for calculating the congestion level of the first link by using the road information of the link.

A computer-readable recording medium storing a computer program according to another embodiment of the present invention is a message subscription information and access information of a user terminal located in a first link among a plurality of links dividing a road according to a predetermined standard. obtaining at least one; calculating the number of user terminals located in the first link by using at least one obtained from the message subscription information and the access information; and calculating the degree of congestion of the first link by using the number of the user terminals located in the first link and the previously obtained road information of the first link, wherein the road is performed by a road congestion calculation device. It may include an instruction for causing the processor to perform a method of calculating the congestion degree of .

According to an embodiment of the present invention, by calculating the congestion level of the road where the user terminal is located by using the message subscription information and access information of the user terminal obtained through the message broker communicating with the MQTT protocol, without a separate facility or device, It is possible to more accurately calculate the congestion level of the road.

1 is a diagram illustrating a road congestion calculation system according to an embodiment of the present invention.
2 is a block diagram illustrating an apparatus for calculating a road congestion level according to an embodiment of the present invention.
3 is a flowchart illustrating a method of calculating a congestion degree of a link according to an embodiment of the present invention.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

1 is a diagram illustrating a road congestion calculation system according to an embodiment of the present invention.

Referring to FIG. 1 , a road congestion calculation system 10 may include a user terminal 100 , a message broker 200 , a road congestion calculation device 300 , and a database 400 .

The user terminal 100 detects the user terminal 100's own location on a map provided by a navigation application or a map application installed in the user terminal 100, and links where the user terminal 100 itself is located among roads on the map. You can create information about (link).

The link may refer to a kind of division in which roads are divided on the map in order to more easily understand the congestion level of the road according to the location of the user terminal 100 . The link can be distinguished by an intersection, a junction, etc. on a connected road, and even if it is a road located between two junctions, the properties of the road (eg, number of lanes, road type, toll gate presence, U-turn lane presence, traffic light presence, etc.) If it changes, it may be divided into two different links.

The user terminal 100 may generate a Mesh ID, Link ID, direction and POL (Position Of Link) as a result of determining its location, and the information on the link may include a Mesh ID, Link ID, and direction. .

The Mesh ID is a region ID, and may mean an identifier indicating the location of the user terminal 100 in a wider area than the link (eg, a square of 20 km×20 km, 25 km×25 km).

Also, the Link ID may mean an identifier indicating a link in which the user terminal 100 is located among roads on the map.

In addition, the direction refers to the direction in which the user terminal 100 moves (advances) on the link. Depending on the embodiment, it may be expressed in an absolute direction such as east, west, south, north, or in a relative direction such as up/down. there is.

The POL means where the user terminal 100 is located on the link, and may be expressed as a traveling distance when the user terminal 100 moves along the link.

The user terminal 100 may apply for a message subscription to the message broker 200 by using the link information as a topic.

At this time, since the user terminal 100 uses information about the link as a topic, as the user terminal 100 moves, when the link in which the user terminal 100 is located is changed (that is, the user terminal 100 is generated When information on a link to be changed is changed), the user terminal 100 may unsubscribe from a message subscription to a topic before the change, and may apply for a message subscription to a topic after the change.

The message broker 200 receives an application for a message subscription for a topic from the user terminal 100, and when an event for the requested topic occurs, a notification message corresponding to the event is transmitted to the user terminal 100 (publish) can do.

When receiving a message subscription or message unsubscription for a topic from the user terminal 100 , the message broker 200 may generate message subscription information based on the message subscription or message unsubscription.

The message subscription information may be expressed as shown in Table 1 below.

Subscribe to messages Unsubscribe from messages {
"broker":"mpp-dev02",
"hook":"on_client_subscribe",
"timestamp":"1587721576856",
"username":"admin2",
"clientId": "tmapclient-123",
"topic":"1122334455"
} {
"broker":"mpp-dev02",
"hook":"on_client_unsubscribe",
"timestamp":"1587721576856",
"username":"admin2",
"clientId": "tmapclient-123",
"topic":"1122334455"
}

Here, the broker indicates the identifier of the message broker, the hook indicates whether the message subscription information is for message subscription or message unsubscription as a property of message subscription information, and timestamp indicates whether the message subscription or message unsubscription is received. Indicates time, username may indicate an identifier of a user who can obtain information by accessing a message broker, clientId may indicate an identifier of the user terminal 100, and topic may indicate a topic for which a message subscription is requested.

In addition, the message broker 200 may store information on subscription or unsubscription of a message most recently received from the user terminal 100 . When the user terminal 100 is connected to or disconnected from the message broker 200 , the message broker 200 may generate access information based on the connection or termination of the connection.

The access information may be expressed as shown in Table 2 below.

connect connection termination {
"broker":"mpp-dev02",
"hook":"on_client_connected",
"timestamp":"1587721576856",
"username":"admin2",
"clientId": "tmapclient-123",
} {
"broker":"mpp-dev02",
"hook":"on_client_disconnected",
"timestamp":"1587721576856",
"username":"admin2",
"clientId": "tmapclient-123",
}

Here, as a property of the access information, the hook indicates whether the access information is for the connection of the user terminal 100 or for the termination of the connection.

The message broker 200 updates message subscription information whenever the user terminal 100 changes whether to subscribe to the message, and updates access information whenever the user terminal 100 changes whether to subscribe to the updated message. Information and updated access information may be transmitted to the road congestion calculation apparatus 300 .

The road congestion calculation apparatus 300 calculates the congestion level of the link in which the user terminal 100 is located, based on the message subscription information and access information of the user terminal 100 received from the message broker 200, and the previously obtained link attribute information. can be calculated. A method by which the road congestion calculation apparatus 300 calculates the congestion level of the link in which the user terminal 100 is located will be described in more detail with reference to FIG. 2 .

The road congestion calculation apparatus 300 may calculate a road congestion level for each link, and store the calculated congestion level for each link in the database 400 .

In the present specification, for convenience of explanation, it has been described that the database 400 is a separate device from the road congestion calculation device 300 , but is not limited thereto. That is, according to an embodiment, the database 400 may be included in the road congestion calculation apparatus 300 .

2 is a block diagram illustrating an apparatus for calculating a road congestion level according to an embodiment of the present invention.

1 and 2 , an apparatus 300 for calculating a road congestion level may include a processor 310 , a transceiver 320 , and a memory 330 .

The processor 310 may control overall functions of the device 300 for calculating road congestion.

The transceiver 320 receives at least one of message subscription information and access information from the message broker 200, and when an event for the topic for which the user terminal 100 has subscribed for subscription occurs, a notification message for the event message It may be transmitted to the user terminal 100 through the broker 200 .

According to an embodiment, the transceiver 320 may transmit and receive messages to and from the message broker 200 using a Message Queue Telemetry Transport (MQTT) protocol.

The memory 330 may store the road congestion calculation model 350 and information necessary for executing the road congestion calculation model 350 .

The processor 310 may load the road congestion calculation model 350 stored in the memory 330 and information necessary for executing the road congestion calculation model 350 to execute the road congestion calculation model 350 .

The processor 310 executes the road congestion calculation model 350, and based on the message subscription information and access information of the user terminal 100 received from the message broker 200, and the previously obtained link attribute information, the user The congestion degree of the link in which the terminal 100 is located may be calculated.

The road congestion calculation model 350 may include a number of terminals determining unit 351 and a link congestion level calculating unit 353 .

The number of terminals determining unit 351 and link congestion calculation unit 353 shown in FIG. 2 conceptually divide the functions of the road congestion calculation model 350 in order to easily explain the functions of the road congestion calculation model 350, However, the present invention is not limited thereto. According to embodiments, the functions of the terminal number determining unit 351 and the link congestion level calculating unit 353 may be merged/separated, and may be implemented as a series of instructions included in one or more programs.

The number of terminals determining unit 351 may calculate the number of user terminals located in the same link by using the message subscription information and access information received from the message broker 200 .

In more detail, the number of terminals determining unit 351 is configured within the same link based on the number of terminals that have applied for message subscription, the number of terminals that have canceled message subscription, and the number of terminals that have terminated access among user terminals located in the link. The number of located user terminals may be calculated.

For example, the number of terminals determining unit 351 may calculate the number of user terminals located in the same link using Equation 1 below.

Here, n _{clients,LinkID} represents the number of user terminals located on the same link, n(sub) represents the number of terminals that have applied for a message subscription while located on the same link, and n(unsub) is a message while located on the same link Represents the number of UEs that have canceled subscription, and n (discon) may indicate the number of UEs that are located on the same link and have terminated access to the message broker 200 .

That is, the number of terminals determining unit 351 counts the number of terminals that have applied for message subscription while being located in the same link, but among the aggregated number of terminals, the number of terminals that have canceled the message subscription and access to the message broker 200 By subtracting the number of terminated terminals, the number of user terminals located in the same link can be calculated. Here, in addition to the terminal that has released the message subscription, the terminal that has terminated the connection to the message broker 200 is also subtracted in order to count the number of terminals whose connection is terminated without canceling the message subscription.

On the other hand, the number of terminals determining unit 351 is connected to the number of terminals that periodically/aperiodically applied for message subscription to the number of user terminals obtained in Equation 1, the number of terminals that cancel the message subscription, and the message broker 200 . By accumulating the number of terminals that have finished , it is possible to calculate the number of user terminals located in the same link.

In such a case, an accumulated error may occur due to accumulating and calculating the number of user terminals. The terminal number determining unit 351 may reduce the accumulated error by using the following two methods.

First, the terminal number determiner 351 compares the time at which the most recently updated message subscription information of the user terminal 100 is updated with the current time, and the time at which the most recently updated message subscription information is updated. When the difference between the current time and the preset time interval (eg, 30 minutes) or more, the number of terminals determining unit 351 may exclude the corresponding user terminal from calculating the number of user terminals located in the link.

Second, the number of terminals determining unit 351 may initialize the periodically or aperiodically accumulated number of user terminals. For example, the number of terminals determining unit 351 may initialize the accumulated number of user terminals in a time period with the least amount of traffic (eg, 4:00 am).

The link congestion calculation unit 353 may calculate the congestion level of the link in which the user terminal 100 is located by using the number of user terminals located in the same link calculated by the number of terminals determining unit 351 and the previously obtained link attribute information. .

The link attribute information may include a length of a link, a road class of the link, a speed limit of the link, and the number of lanes of the link.

In more detail, the link congestion level calculator 353 may calculate the link congestion level using Equation 2 below.

Here, congestion _i represents the congestion degree of the i-th (here, i is a natural number) link, α represents a weight for converting the number of user terminals 100 in the link to the total number of vehicles in the link, n _{client, i} represents the number of user terminals 100 located in the i-th link, l _i represents the length of the i-th link, v _max,i represents the speed limit (maximum speed) of the i-th link, safety time may represent a time taken to avoid when an emergency occurs, frc _i may represent a road class of the i-th link, and lane _i may represent the number of lanes of the i-th link.

First, looking at α, among the vehicles located in the link, there are terminals that use the same navigation application as the user terminal 100, but there may also be terminals that do not. Therefore, in order to more accurately calculate the number of vehicles located in the link, it is necessary to further consider the number of vehicles (terminals) that are not grasped by the terminal number determining unit 351 . To this end, the link congestion calculation unit 353 calculates the total number of terminals located in the link by multiplying the number of user terminals determined by the terminal number determination unit 351 by the weight α. According to an embodiment, the weight α is a value obtained by dividing the total number of annual highway users (eg, 4.4 million/day) by the total number of users (eg, 270,000/day) using the same navigation application as the user terminal 100 (eg, 270,000/day) , 16.3), but is not limited thereto.

Next, looking at li/(v _max,i *safe time), it is intended to normalize the congestion of the link to 1 when all vehicles in the link are driving while maintaining a safe distance in a state in which the link is full. At this time, since the distance between vehicles is also reduced when the speed of the vehicle is reduced due to vehicle congestion in general, congestion can be calculated based on the distance between vehicles. In addition, when an emergency situation (accident of a vehicle in front, risk of collision, etc.) occurs, the avoidance time (eg, 4 seconds) required to recognize and avoid it is set (defined), the safety distance between vehicles (distance_safety) can be defined as the product of the link speed limit and avoidance time (ie, distance_safety = v _max,i * safe time). Accordingly, when the length of the link l _i is divided by the safety distance between vehicles (distance_safety = v _max,i * safe time), the congestion of the link can be normalized.

Finally, looking at the road grade ( frc _i ) of the link, the grade of the road may be represented as shown in Table 3 below.

type of road grade of road frc highway A 1/10 Urban Expressway A 1/10 national road B 1/8 national support map B 1/8 province C 1/6 main road 1 C 1/6 main road 2 C 1/6 main road 3 C 1/6

As shown in Table 3, according to the embodiment, the road grade frc _i may be divided into three grades according to the type of road according to the maximum speed. This is because the congestion level of the link is dependent on the maximum speed limit of the road (i.e., even if there are the same number of vehicles, vehicles can be expected to exit quickly on a road with high maximum speed), and therefore, the higher the road grade (i.e. , the higher the maximum speed limit, the smaller the road grade frc _i as a weight applied to the congestion level of the link.

The link congestion level calculator 353 may calculate the link congestion level periodically/aperiodically. According to an embodiment, the link congestion level calculator 353 may update the link congestion level whenever message subscription information and/or access information of the user terminal 100 are updated.

The link congestion level calculator 353 may store the periodically/aperiodically calculated link congestion level in the database 400 .

3 is a flowchart illustrating a method of calculating a congestion degree of a link according to an embodiment of the present invention.

1 to 3 , the terminal number determining unit 351 receives message subscription information and access information of the user terminal 100 from the message broker 200 ( S300 ), and the received message subscription information and access information can be used to calculate the number of terminals located in the same link as the user terminal 100 (S310).

The link congestion calculation unit 353 uses the previously obtained link attribute information and the number of terminals located in the same link as the user terminal 100 calculated by the terminal number determining unit 351, where the user terminal 100 is located. The congestion level of the link may be calculated (S320).

Combinations of each block in the block diagram attached to the present invention and each step in the flowchart may be performed by computer program instructions. These computer program instructions may be embodied in the encoding processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions executed by the encoding processor of the computer or other programmable data processing equipment may correspond to each block of the block diagram or Each step of the flowchart creates a means for performing the functions described. These computer program instructions may also be stored in a computer-usable or computer-readable memory which may direct a computer or other programmable data processing equipment to implement a function in a particular way, and thus the computer-usable or computer-readable memory. The instructions stored in the block diagram may also produce an item of manufacture containing instruction means for performing a function described in each block of the block diagram or each step of the flowchart. The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for carrying out the functions described in each block of the block diagram and in each step of the flowchart.

Further, each block or each step may represent a module, segment, or portion of code comprising one or more executable instructions for executing specified logical function(s). It should also be noted that, in some alternative embodiments, it is possible for the functions recited in blocks or steps to occur out of order. For example, it is possible that two blocks or steps shown one after another may in fact be performed substantially simultaneously, or that the blocks or steps may sometimes be performed in the reverse order according to the corresponding function.

The above description is merely illustrative of the technical idea of the present invention, and various modifications and variations will be possible without departing from the essential quality of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: Road Congestion Calculation System
100: user terminal
200: message broker
300: road congestion calculation device
350: road congestion calculation model
351: terminal number determination unit
353: link congestion calculation unit
400: database

Claims (11)

A method for calculating a road congestion level by a road congestion calculation device, the method comprising:
obtaining at least one of message subscription information and access information of a user terminal located in a first link among a plurality of links dividing the road according to a predetermined criterion; and
calculating the number of user terminals located in the first link by using at least one obtained from the message subscription information and the access information; and
using the number of the user terminals located in the first link and previously obtained road information of the first link, calculating the degree of congestion of the first link
How to calculate the congestion level of a road. According to claim 1,
The step of obtaining at least one of the message subscription information and the access information comprises:
Receive at least one of the message subscription information and the access information from a message broker that communicates with the user terminal through MQTT (Message Queue Telemetry Transport) protocol,
The message subscription information is generated based on a message subscription request or message subscription cancellation applied by the user terminal to the message broker using the first link as a topic
How to calculate the congestion level of a road. According to claim 1,
The road information is
including at least one of a length of the first link, a road class, a speed limit, and the number of lanes
How to calculate the congestion level of a road. According to claim 1,
Calculating the number of user terminals located in the first link comprises:
Using the number of user terminals that applied for message subscription, the number of user terminals that applied for message cancellation, and the number of user terminals that have terminated access to a message broker that communicates with the user terminal using the MQTT protocol, located in the first link to count the number of user terminals
How to calculate the congestion level of a road. According to claim 1,
Calculating the congestion degree of the first link comprises:
determining the number of vehicles located in the first link by calculating a preset weight on the number of the user terminals located in the first link; and
calculating the congestion level of the first link by using the number of vehicles located in the first link and road information of the first link
How to calculate the congestion level of a road. a transceiver for obtaining at least one of message subscription information and access information of a user terminal located in a first link among a plurality of links dividing a road according to a predetermined criterion; and
The number of user terminals located in the first link is calculated using at least one obtained from the message subscription information and the access information, and the number of the user terminals located in the first link and the obtained first link A processor for calculating the congestion level of the first link by using the road information of
Road congestion calculator. 7. The method of claim 6,
The processor is
Receive at least one of the message subscription information and the access information from a message broker communicating with the user terminal using the MQTT (Message Queue Telemetry Transport) protocol using the transceiver,
The message subscription information is generated based on a message subscription request or message subscription cancellation applied by the user terminal to the message broker using the first link as a topic
Road congestion calculator. 7. The method of claim 6,
The road information is
including at least one of a length of the first link, a road class, a speed limit, and the number of lanes
Road congestion calculator. 9. The method of claim 8,
The processor is
Using the number of user terminals that applied for message subscription, the number of user terminals that applied for message cancellation, and the number of user terminals that have terminated access to a message broker that communicates with the user terminal using the MQTT protocol, located in the first link to count the number of user terminals
Road congestion calculator. 7. The method of claim 6,
The processor is
determining the number of vehicles located in the first link by calculating a preset weight on the number of the user terminals located in the first link;
calculating the congestion level of the first link by using the number of vehicles located in the first link and road information of the first link
Road congestion calculator. As a computer program stored in a computer-readable recording medium,
The computer program is
A method comprising instructions for causing a processor to perform the method according to any one of claims 1 to 5.
computer program.

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