A method for implementing an intelligent traffic monitoring and early warning system

Abstract

The present invention provides a method for implementing an intelligent traffic monitoring and early warning system. After detecting a traffic accident, a vehicle node sends a collection message containing coordinates. Upon receiving the collection message, an edge node creates a data table entry. The vehicle node sends a subscription message containing the coordinates to establish a subscription table entry. Upon receiving the subscription message, the edge node updates or creates a subscription table entry. After creating the data table entry, the edge node sends an early warning message containing the ID and coordinates of the road segment according to the subscription table entry that meets the requirements. Using the method for implementing an intelligent traffic monitoring and early warning system provided by the present invention, vehicles can quickly obtain real-time road conditions, the scale of the traffic accident, road obstacles, and other information, enabling safe driving. The system has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of monitoring and early warning technology, and in particular to a method for realizing an intelligent traffic monitoring and early warning system. Background Art

[0002] Prompt access to comprehensive, real-time traffic information is crucial for safe driving and a crucial measure for preventing road accidents. Current traffic warning systems primarily rely on request-response and broadcast methods for obtaining this information, resulting in poor real-time performance and a low success rate.

[0003] This system effectively solves this problem and realizes real-time road safety monitoring and early warning, ensuring that each vehicle can obtain road safety information in a timely manner and ensure safe driving. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for realizing an intelligent traffic monitoring and early warning system in view of the shortcomings of the existing technology.

[0005] Technical solution: The present invention discloses a method for implementing an intelligent traffic monitoring and early warning system, comprising the following steps:

[0006] After detecting a traffic accident, a vehicle node sends a collection message containing coordinates. When the distance between the vehicle node receiving the collection message and the local edge node is less than the distance between the coordinates in the collection message and the local edge node, and no collection message with different coordinates is received within time T1, the vehicle node updates the coordinates in the collection message with its own coordinates, adds its collected data to the data set in the collection message, and forwards it. After receiving the collection message, the edge node creates a data table entry.

[0007] The vehicle node sends a subscription message containing coordinates to establish a subscription table entry. When the distance between the vehicle node receiving the subscription message and the local edge node is less than the distance between the coordinates in the subscription message and the local edge node, and no subscription message with different coordinates is received within time T2, the vehicle node updates the coordinates in the subscription message with its own coordinates and forwards it. After receiving the subscription message, the edge node updates or creates a subscription table entry.

[0008] After creating the data table entry, the edge node sends a warning message containing the driving section ID and coordinates according to the qualified subscription table entries; when the vehicle node that receives the warning message is driving on the section identified by the warning message, and the distance from the local edge node is greater than the distance between the coordinates in the warning message and the local edge node, and no warning message with different coordinates is received within time T3, the vehicle node updates the coordinates in the warning message to its own coordinates and then forwards it.

[0009] In the method,

[0010] The edge nodes are deployed at intersections, and the road between two adjacent edge nodes constitutes a road section; the vehicle node obtains the coordinates of each edge node through an electronic map and determines the edge node closest to itself as the local edge node; wherein, each edge node has a unique node ID for distinguishing other edge nodes in the system.

[0011] In the method,

[0012] The data table entries maintained by the edge node include a timestamp, a road segment ID, and a data set, wherein the road segment ID is used to identify the road segment and is a unique identifier pre-set for each road segment;

[0013] The collection message sent by the vehicle node includes the following information: the real-time coordinates of the current vehicle node, the unique node ID of the local edge node of the current vehicle node, the unique section ID of the current section, and a data set including the data collected by the vehicle node.

[0014] In the method,

[0015] The time T1 is calculated according to formula (1):

[0016] (1);

[0017] Among them, x1 and y1 are the horizontal and vertical coordinates of the vehicle node that receives the collection message, x0 and y0 are the horizontal and vertical coordinates of the edge node identified by the node ID in the received collection message, x2 and y2 are the horizontal and vertical coordinates of the coordinates in the received collection message, and T0 is the time threshold, which is set in advance.

[0018] In the method,

[0019] After receiving the collection message, the edge node creates a data table entry, including:

[0020] The timestamp in the created data table entry is equal to the time when the collection message is received;

[0021] The road segment ID and data set in the created data table entry are respectively equal to the road segment ID and data set in the collection message.

[0022] In the method,

[0023] The subscription table entry maintained by each edge node includes a driving segment ID, a data segment ID, and a lifetime; wherein the driving segment refers to the segment ID of the driving segment of the subscribed vehicle, and the data segment ID refers to the segment ID of the segment where the traffic accident occurred;

[0024] The subscription message sent by the vehicle node includes the following information: the real-time coordinates of the current vehicle node, the unique node ID of the local edge node of the current vehicle node, the unique section ID of the current section, and the unique section ID of the target section for which the vehicle node needs to obtain traffic accident data.

[0025] In the method,

[0026] The time T2 is calculated according to formula (2):

[0027] (2);

[0028] Among them, x4 and y4 are the horizontal and vertical coordinates of the vehicle node that received the subscription message, x3 and y3 are the horizontal and vertical coordinates of the edge node identified by the node ID in the received subscription message, x5 and y5 are the horizontal and vertical coordinates of the coordinates in the received subscription message, and T0 is the time threshold, which is set in advance.

[0029] In the method,

[0030] After receiving the subscription message, the edge node updates or creates a subscription table entry, including:

[0031] The edge node receiving the subscription message determines whether there is a subscription entry whose driving segment ID and data segment ID are respectively equal to the driving segment ID and data segment ID in the subscription message;

[0032] If it exists, update the lifetime of the subscription entry to the maximum lifetime;

[0033] If it does not exist, create a subscription table entry, the driving segment ID and data segment ID of the subscription table entry are respectively equal to the driving segment ID and data segment ID in the subscription message, and the lifetime is equal to the maximum lifetime.

[0034] In the method,

[0035] The qualified subscription table item is a data segment ID that is equal to the segment ID in the data table item created by the edge node;

[0036] The warning message sent by the edge node includes the following information: the coordinates of the edge node itself, the node ID of the edge node itself, the data table item created by the edge node, and the driving section ID in the subscription table item that meets the conditions.

[0037] In the method,

[0038] The time T3 is calculated according to formula (3):

[0039] (3);

[0040] Among them, x7 and y7 are the horizontal and vertical coordinates of the vehicle node that received the warning message, x6 and y6 are the horizontal and vertical coordinates of the edge node identified by the node ID in the received warning message, x8 and y8 are the horizontal and vertical coordinates of the coordinates in the received warning message, and T0 is the time threshold, which is set in advance.

[0041] Beneficial effects: The present invention provides a method for implementing an intelligent traffic monitoring and early warning system. Through the method for implementing an intelligent traffic monitoring and early warning system provided by the present invention, vehicles can quickly obtain real-time road conditions, the scale of traffic accidents, road obstacles and other information, achieve safe driving, and have broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0043] Figure 1 A flowchart of a method for implementing an intelligent traffic monitoring and warning system according to an embodiment of the present invention;

[0044] Figure 2 A schematic diagram of a process for creating a data table according to an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of a process for creating a subscription table according to an embodiment of the present invention;

[0046] Figure 4 Schematic diagram of the early warning process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It is apparent that the described embodiments are only a portion of the embodiments of the present invention, rather than all of them. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without requiring creative effort are within the scope of protection of the present invention.

[0048] Unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The terms "including" or "comprising" used in the embodiments of the present invention neither limit the shapes, numbers, steps, actions, operations, components, originals and / or their groups mentioned, nor exclude the appearance or addition of one or more other different shapes, numbers, steps, actions, operations, components, originals and / or their groups, or the addition of these. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number and order of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0049] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn in accordance with actual proportional relationships, and that the techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and devices shown should be considered part of the authorized specification. In all examples shown and discussed herein, any specific other examples may have different values. It should be noted that similar symbols and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0050] In the description of the embodiments of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in the embodiments of the present invention and the features of different embodiments or examples, unless they are mutually inconsistent.

[0051] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0052] Figure 1 FIG. 1 is a flow chart of a method for implementing an intelligent traffic monitoring and warning system according to an embodiment of the present invention. Figure 1 As shown, a method for implementing an intelligent traffic monitoring and warning system includes the following steps:

[0053] After detecting a traffic accident, the vehicle node sends a collection message containing coordinates; when the distance between the vehicle node receiving the collection message and the local edge node is less than the distance between the coordinates in the collection message and the local edge node, and no collection message with different coordinates is received within time T1, the vehicle node updates the coordinates in the collection message to its own coordinates, and adds the data collected by itself to the data set in the collection message and forwards it; the edge node creates a data table entry after receiving the collection message.

[0054] The vehicle node sends a subscription message containing coordinates to establish a subscription table entry; when the distance between the vehicle node that receives the subscription message and the local edge node is less than the distance between the coordinates in the subscription message and the local edge node, and no subscription message with different coordinates is received within time T2, the vehicle node updates the coordinates in the subscription message to its own coordinates and forwards it; after receiving the subscription message, the edge node updates or creates a subscription table entry.

[0055] After creating the data table entry, the edge node sends a warning message containing the driving section ID and coordinates according to the qualified subscription table entries; when the vehicle node that receives the warning message is driving on the section identified by the warning message, and the distance from the local edge node is greater than the distance between the coordinates in the warning message and the local edge node, and no warning message with different coordinates is received within time T3, the vehicle node updates the coordinates in the warning message to its own coordinates and then forwards it.

[0056] The implementation method of the intelligent traffic monitoring and early warning system of the embodiment of the present invention can enable vehicles to quickly obtain real-time road conditions, the scale of traffic accidents, road obstacles and other information through the implementation method of the intelligent traffic monitoring and early warning system provided by the embodiment of the present invention, thereby achieving safe driving and having broad application prospects.

[0057] Figure 2 This is a flowchart for creating a data table according to an embodiment of the present invention. The system is composed of vehicle nodes and edge nodes. Edge nodes can be base stations. Edge nodes are located at intersections, and the road between two intersections is called a road segment. Vehicle nodes refer to edge nodes that meet condition 1 as their local edge nodes.

[0058] Condition 1: Among all edge nodes, the vehicle node is closest to the edge node;

[0059] Each edge node has a unique node ID, such as hardware address or MAC address;

[0060] Each vehicle node obtains the coordinates of the edge node from the electronic map;

[0061] Each edge node stores a data table, and the data table entries contain timestamps, road segment IDs, and data sets;

[0062] Each road segment is uniquely identified by a road segment ID, which is pre-set;

[0063] The collection message contains message ID, coordinates, road segment ID, node ID and data set;

[0064] The coordinates in the collection message refer to the real-time coordinates of the vehicle node that sends or forwards the collection message, not the coordinates of the traffic accident. The location of the traffic accident is identified by the road section ID. The function of the coordinates in the collection message is to determine whether the coordinates of the vehicle receiving the collection message are closer to the edge node than the vehicle node forwarding the collection message.

[0065] The local edge node of vehicle node V1 is ED1. When driving on the road segment with the road segment ID RS1, vehicle node V1 detects a traffic accident and executes the following process:

[0066] Step 101: Start;

[0067] Step 102: Vehicle node V1 creates traffic accident data D1, such as photos of the traffic accident, and sends a collection message with a message ID of 1, its own coordinates, a node ID equal to the node ID of edge node ED1, and a road segment ID of RS1. The data set only contains its own data D1, i.e., {D1}.

[0068] Step 103: If the edge node ED1 receives the collection message, execute step 107; otherwise, execute step 104.

[0069] Step 104: The vehicle node that receives the collection message determines whether the distance between its own coordinates and the edge node coordinates identified by the node ID in the collection message is less than the distance between the coordinates in the collection message and the edge node coordinates identified by the node ID. If so, execute step 105; otherwise, execute step 108.

[0070] Step 105: The vehicle node that receives the collection message calculates the time T1 according to formula (1). In formula (1), x1 and y1 are the horizontal coordinate and vertical coordinate of the vehicle node that receives the collection message, x0 and y0 are the horizontal coordinate and vertical coordinate of the edge node identified by the node ID in the received collection message, x2 and y2 are the horizontal coordinate and vertical coordinate of the coordinate in the received collection message, and T0 is the time threshold, which is preset. If no collection message is received within time T1, step 106 is executed, otherwise step 108 is executed.

[0071] (1)

[0072] Step 106: The vehicle node that receives the collection message sets the coordinates in the collection message as its own coordinates and adds its collected data to the data set in the collection message. For example, if the collected data is a picture of the surrounding road conditions, the vehicle node forwards the collection message and executes step 103. For example, if the coordinates in the collection message are (x2, y2) and the coordinates of the vehicle receiving the collection message are (x1, y1), after executing step 106, the coordinates in the collection message become (x1, y1).

[0073] Step 107: The edge node that receives the collection message creates a data table entry. The timestamp of the data table entry is the time when the collection message is received, and the road segment ID and data set are respectively equal to the road segment ID and data set in the collection message.

[0074] Step 108: End.

[0075] The main purpose of steps 101-108 is to send traffic accident data from the vehicle node to the local edge node. The innovations of this algorithm include: (1) Traffic accidents contain data collected by multiple vehicle nodes. The coordinates in the collection message are the real-time coordinates collected by the vehicle that sends or forwards the collection message, thus ensuring the real-time and accuracy of the coordinates; (2) The waiting time T1 is defined to minimize the waiting time of the vehicle node closest to the local edge node, and then forward the collection message, thereby effectively reducing the forwarding hops of the collection message and reducing the data transmission delay; (3) Traffic accident data is forwarded to the local edge node through a few vehicle nodes (rather than all vehicle nodes), reducing the data communication cost and delay and improving the success rate. In the collection message, the coordinates refer to the real-time coordinates of the vehicle node that sends or forwards the collection message, not the coordinates of the traffic accident. The location of the traffic accident is identified by the road section ID. The role of the coordinates in the collection message is to determine whether the coordinates of the vehicle that receives the collection message are closer to the edge node than the vehicle node that forwards the collection message, so that traffic safety data can be transmitted to the edge node at the fastest speed and lowest cost. Existing traffic warning systems use a broadcast method to implement warnings, meaning that each vehicle node forwards the received message. This broadcast method generates a large amount of redundant data, causing network congestion, a sharp increase in packet loss rate, and a sharp increase in data transmission delay. To address this problem, the present invention proposes a definition of waiting time T1, as shown in formula (1). The purpose of waiting time T1 is to select a small number of vehicle nodes to forward traffic accident data, thereby avoiding network congestion, significantly reducing packet loss rate, and ensuring that local edge nodes obtain real-time traffic data. Specifically, after a vehicle sends a collection message, all of its neighboring vehicles can receive the collection message. In order to ensure that only the optimal neighboring vehicle forwards the collection message, rather than all neighboring vehicles forwarding the collection message, the present invention proposes a definition of the waiting time T1, as shown in formula (1). According to formula (1), the closer the neighboring vehicle node that receives the collection message is to the local edge node, the smaller the value of T1, that is, the shorter the waiting time. According to steps 105 and 106, among all the neighboring vehicles that receive the collection message, the neighboring vehicle node closest to the local edge node has the shortest waiting time T1, so it is the first neighboring vehicle node to forward the collection message, that is, the neighboring vehicle node that "does not receive any collection message within time T1". After other neighboring vehicles receive the collection message forwarded by the neighboring vehicle node, they will no longer forward the collection message, thereby effectively avoiding network congestion and ensuring that the data reaches the local edge node correctly. Since the coordinates in the collection message refer to the real-time coordinates of the vehicle node that sends or forwards the collection message, as shown in step 106, the neighboring vehicle node "sets the coordinates in the collection message to its own current coordinates and forwards the collection message".

[0076] For example, after vehicle node V0 sends or forwards a collection message, all 10 neighboring vehicle nodes receive the collection message. Each neighboring vehicle node Vx (x = 1...10) calculates its own waiting time according to formula (1). For neighboring vehicle node Vx, (x1, y1) is Vx's real-time coordinate, and (x2, y2) is the real-time coordinate when vehicle node V0 sends or forwards the collection message. In this way, the neighboring vehicle node closest to the local edge node has the shortest waiting time and therefore forwards the collection message. The other nine neighboring vehicle nodes receive the collection message forwarded by the neighboring vehicle node within the waiting time and therefore do not forward the collection message. This effectively avoids network congestion and ensures that data is correctly and promptly forwarded to the local edge node.

[0077] Figure 3 This is a flowchart for creating a subscription table according to an embodiment of the present invention. Each edge node stores a subscription table. The subscription table entries contain the driving segment ID, data segment ID, and lifetime. The driving segment refers to the segment ID of the subscribing vehicle's driving segment, and the data segment ID refers to the segment ID of the segment where the traffic accident occurred.

[0078] The subscription message contains the message ID, coordinates, node ID, driving section ID and data section ID;

[0079] The local edge node of vehicle node V2 is ED1. When driving on the road segment with the road segment ID RS2, if you want to obtain the traffic accident data that occurred on the road segment with the road segment ID RS1, you need to perform the following process:

[0080] Step 201: Start;

[0081] Step 202: Vehicle node V2 sends a subscription message with a message ID of 2, its own coordinates, a node ID equal to the node ID of edge node ED1, a driving segment ID of RS2, and a data segment ID of RS1.

[0082] Step 203: If the edge node ED1 receives the subscription message, execute step 207; otherwise, execute step 204.

[0083] Step 204: The vehicle node that receives the subscription message determines whether the distance between its own coordinates and the coordinates of the edge node identified by the node ID in the subscription message is less than the distance between the coordinates in the subscription message and the coordinates of the edge node identified by the node ID. If so, step 205 is executed; otherwise, step 208 is executed.

[0084] Step 205: The vehicle node that receives the subscription message calculates the time T2 according to formula (2). In formula (2), x4 and y4 are the horizontal coordinate and vertical coordinate of the vehicle node that receives the subscription message, x3 and y3 are the horizontal coordinate and vertical coordinate of the edge node identified by the node ID in the received subscription message, x5 and y5 are the horizontal coordinate and vertical coordinate of the coordinate in the received subscription message, and T0 is the time threshold, which is preset. If no subscription message is received within time T2, step 206 is executed, otherwise step 208 is executed.

[0085] (2)

[0086] Step 206: The vehicle node that receives the subscription message sets the coordinates in the subscription message as its own coordinates, forwards the subscription message, and executes step 203. For example, if the coordinates in the subscription message are (x5, y5), and the vehicle coordinates received in the subscription message are (x4, y4), after executing step 206, the coordinates in the subscription message become (x4, y4).

[0087] Step 207: The edge node that receives the subscription message determines whether there is a subscription entry whose driving segment ID and data segment ID are respectively equal to the driving segment ID and data segment ID in the subscription message. If so, the lifetime of the subscription entry is set to the maximum lifetime, for example, 30 minutes. Otherwise, a subscription entry is created whose driving segment ID and data segment ID are respectively equal to the driving segment ID and data segment ID in the subscription message, and whose lifetime is equal to the maximum lifetime.

[0088] Step 208: End.

[0089] The goal of steps 201-208 is to establish a subscription table entry at the local edge node. The innovations of this process include: (1) defining subscription table entries, each of which contains a driving segment ID and a data segment ID; (2) defining a waiting time T2, so that the vehicle node that receives the subscription message and is closest to the local edge node forwards the subscription message, while other vehicle nodes that receive the subscription message no longer forward the subscription message, thereby effectively reducing the number of forwarding hops for the subscription message, avoiding network congestion, and reducing data transmission delay; (3) a small number of optimal vehicle nodes forward the subscription message to the local edge node, reducing the data communication cost, avoiding network congestion, and improving the success rate. In the subscription table creation process, the coordinates in the subscription message refer to the real-time coordinates of the vehicle node that sends or forwards the subscription message. Its function is to determine whether the coordinates of the vehicle that receives the subscription message are closer to the local edge node than the vehicle node that forwards the subscription message, and then quickly establish the subscription table. The existing traffic warning system uses broadcasting to forward messages. This broadcasting method generates a large amount of redundant data, causing network congestion, a sharp increase in packet loss rate, and a sharp increase in data transmission delay. In order to solve this problem, the present invention proposes a definition of waiting time T2, as shown in formula (2). Its purpose is to screen the optimal vehicle node to forward the subscription message, thereby avoiding network congestion and significantly reducing the packet loss rate. Specifically, after a vehicle sends a subscription message, all its neighboring vehicles can receive the subscription message. In order to ensure that only a few optimal neighboring vehicles forward the subscription message, rather than all neighboring vehicles forward the subscription message, the present invention proposes formula (2). According to formula (2), the closer the neighboring vehicle node that receives the subscription message is to the edge node identified by the node ID in the subscription message, the smaller the value of T2, that is, the shorter the waiting time. According to steps 205 and 206, among all the neighboring vehicles that receive the subscription message, the neighboring vehicle node closest to the local edge node has the shortest waiting time T2, so it is the first neighboring vehicle node to forward the subscription message, that is, the neighboring vehicle node that "has not received any subscription message within time T2". After other neighboring vehicles receive the subscription message forwarded by the neighboring vehicle node, they no longer forward the subscription message, thereby effectively avoiding network congestion and ensuring the correct forwarding of the subscription message. Since the coordinates in the subscription message refer to the real-time coordinates of the vehicle node that sends or forwards the subscription message, as shown in step 206, "the vehicle node that receives the subscription message sets the coordinates in the subscription message as its own coordinates and forwards the subscription message."

[0090] Figure 4 Schematic diagram of the warning process of an embodiment of the present invention. The warning message includes a message ID, coordinates, node ID, data table entry, and travel section ID;

[0091] After edge node ED1 creates data entry DE1, it performs the following operations for each subscription entry SE1 that meets condition 2:

[0092] Condition 2: The data segment ID of the subscription entry is equal to the segment ID in data entry DE1;

[0093] Step 301: Start;

[0094] Step 302: Edge node ED1 sends an early warning message with a message ID equal to 3, coordinates equal to its own coordinates, node ID equal to its own node ID, data entry equal to DE1, and driving segment ID equal to the driving segment ID of subscription entry SE1.

[0095] Step 303: The vehicle node that receives the warning message determines whether it is traveling on the road segment identified by the road segment ID in the warning message. If so, step 304 is executed; otherwise, step 307 is executed.

[0096] Step 304: The vehicle node that receives the warning message determines whether the distance between its own coordinates and the coordinates of the edge node identified by the node ID in the warning message is greater than the distance between the coordinates in the warning message and the coordinates of the edge node identified by the node ID. If so, step 305 is executed; otherwise, step 307 is executed.

[0097] Step 305: The vehicle node that receives the warning message calculates the time T3 according to formula (3). In formula (3), x7 and y7 are the horizontal coordinate and vertical coordinate of the vehicle node that receives the warning message, x6 and y6 are the horizontal coordinate and vertical coordinate of the edge node identified by the node ID in the received warning message, x8 and y8 are the horizontal coordinate and vertical coordinate of the coordinate in the received warning message, and T0 is the time threshold, which is preset. If no warning message is received within time T3, step 306 is executed, otherwise step 307 is executed.

[0098] (3)

[0099] Step 306: The vehicle node that receives the warning message sets the coordinates in the warning message as its own coordinates, forwards the warning message, and executes step 303. For example, if the coordinates in the warning message are (x8, y8), and the coordinates of the vehicle receiving the warning message are (x7, y7), after executing step 306, the coordinates in the warning message become (x7, y7).

[0100] Step 307: End.

[0101] The purpose of steps 301-307 is to send traffic accident data to subscribing vehicle nodes to achieve real-time warning. The innovations of this algorithm include: (1) pushing traffic accident data according to subscription items and sending data only to interested vehicle nodes; (2) defining a waiting time T3 so that the neighboring vehicle node that receives the warning message and is farthest from the local edge node has the shortest waiting time, thereby forwarding the warning message, thereby effectively reducing the forwarding hops of the warning message and reducing the data push delay; (3) Traffic accident data is sent to interested vehicle nodes through a few optimal vehicle nodes, reducing data communication costs and delays, avoiding network congestion, and improving the success rate.

[0102] In the early warning process, the coordinates in the early warning message refer to the real-time coordinates of the vehicle node that sends or forwards the early warning message. Their function is to determine whether the distance between the coordinates of the vehicle receiving the early warning message and the coordinates of the edge node that sent the early warning message is greater than the distance between the coordinates of the vehicle node forwarding the early warning message and the coordinates of the edge node that sent the early warning message, thereby quickly publishing the early warning data to subscribing vehicles. Existing traffic early warning systems forward messages using a broadcast method. This broadcast method generates a large amount of redundant data, causing network congestion, a sharp increase in packet loss rate, and a sharp increase in data transmission delay. To address this problem, the present invention proposes a definition of waiting time T3, as shown in formula (3). Its purpose is to select the optimal vehicle node to forward the early warning message, thereby avoiding network congestion and significantly reducing packet loss rate and early warning delay. Specifically, after an edge node sends a warning message or a vehicle forwards a warning message, all of its neighboring vehicles can receive the warning message. In order to ensure that only a few optimal neighboring vehicles forward the warning message, rather than all neighboring vehicles forwarding the warning message, the present invention proposes formula (3). According to formula (3), the farther the neighboring vehicle node receiving the warning message is from the edge node identified by the node ID in the warning message, the smaller the value of T3, that is, the shorter the waiting time. According to steps 305 and 306, among all neighboring vehicles receiving the warning message, the neighboring vehicle node farthest from the edge node identified by the node ID in the warning message has the shortest waiting time T3, and is therefore the first neighboring vehicle node to forward the warning message, that is, the neighboring vehicle node that "has not received any warning message within time T3". After other neighboring vehicles receive the warning message forwarded by this neighboring vehicle node, they no longer forward the warning message, thereby effectively avoiding network congestion and ensuring the correct forwarding of the warning message. Since the coordinates in the warning message refer to the real-time coordinates of the vehicle node that sends and forwards the warning message, as shown in step 306, "the vehicle node that receives the warning message sets the coordinates in the warning message as its own coordinates and forwards the warning message."

[0103] Example 1

[0104] Based on the simulation parameters in Table 1, this embodiment simulates an implementation method of an intelligent traffic monitoring and warning system according to the present invention. Performance analysis is as follows: When the distance between the vehicle node and the edge node is large, the success rate of the vehicle node acquiring traffic warning data decreases. However, when the distance between the vehicle node and the edge node is large, the success rate of the vehicle node acquiring traffic warning data increases, with an average success rate of 98.3%.

[0105] Table 1

[0106]

[0107] The present invention provides a method for implementing an intelligent traffic monitoring and warning system. Numerous methods and approaches exist for implementing this technical solution. The foregoing description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art may make improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Any components not specified in this embodiment may be implemented using existing technologies.

Claims

1. A method for implementing an intelligent traffic monitoring and early warning system, characterized in that: The following steps are involved: After detecting a traffic accident, a vehicle node sends a collection message containing coordinates. When the distance between the vehicle node receiving the collection message and the local edge node is less than the distance between the coordinates in the collection message and the local edge node, and no collection message with different coordinates is received within time T1, the vehicle node updates the coordinates in the collection message with its own coordinates, adds its collected data to the data set in the collection message, and forwards it. After receiving the collection message, the edge node creates a data table entry; The vehicle node sends a subscription message containing coordinates to establish a subscription table entry. When the distance between the vehicle node receiving the subscription message and the local edge node is less than the distance between the coordinates in the subscription message and the local edge node, and no subscription message with different coordinates is received within time T2, the vehicle node updates the coordinates in the subscription message with its own coordinates and forwards it. After receiving the subscription message, the edge node updates or creates a subscription table entry. After creating a data table entry, the edge node sends a warning message containing the road segment ID and coordinates according to the qualified subscription table entry. When a vehicle node that receives the warning message is traveling on the road segment identified by the warning message, and the distance between it and the local edge node is greater than the distance between the coordinates in the warning message and the local edge node, and no warning message with different coordinates is received within time T3, the vehicle node updates the coordinates in the warning message to its own coordinates and forwards the message. The time T1 is calculated according to formula (1): (1)； Where x1 and y1 are the horizontal and vertical coordinates of the vehicle node that received the collection message, x0 and y0 are the horizontal and vertical coordinates of the edge node identified by the node ID in the received collection message, x2 and y2 are the horizontal and vertical coordinates of the coordinates in the received collection message, and T0 is the time threshold, which is preset; The time T2 is calculated according to formula (2): （2）； Among them, x4 and y4 are the horizontal coordinate and vertical coordinate of the vehicle node that received the subscription message, x3 and y3 are the horizontal coordinate and vertical coordinate of the edge node identified by the node ID in the received subscription message, and x5 and y5 are the horizontal coordinate and vertical coordinate of the coordinate in the received subscription message; The time T3 is calculated according to formula (3): (3)； Among them, x7 and y7 are the horizontal and vertical coordinates of the vehicle node that received the warning message, x6 and y6 are the horizontal and vertical coordinates of the edge node identified by the node ID in the received warning message, and x8 and y8 are the horizontal and vertical coordinates of the coordinates in the received warning message.

2. The method for implementing an intelligent traffic monitoring and early warning system according to claim 1, characterized in that: The edge nodes are deployed at intersections, and the road between two adjacent edge nodes constitutes a road section; the vehicle node obtains the coordinates of each edge node through an electronic map and determines the edge node closest to itself as the local edge node; wherein, each edge node has a unique node ID for distinguishing other edge nodes in the system.

3. The method for implementing an intelligent traffic monitoring and early warning system according to claim 1, characterized in that: The data table entries maintained by the edge node include a timestamp, a road segment ID, and a data set, wherein the road segment ID is used to identify the road segment and is a unique identifier pre-set for each road segment; The collection message sent by the vehicle node includes the following information: the real-time coordinates of the current vehicle node, the unique node ID of the local edge node of the current vehicle node, the unique section ID of the current section, and a data set including the data collected by the vehicle node.

4. The method for implementing an intelligent traffic monitoring and warning system according to any one of claims 1 to 3, characterized in that: After receiving the collection message, the edge node creates a data table entry, including: The timestamp in the created data table entry is equal to the time when the collection message is received; The road segment ID and data set in the created data table entry are respectively equal to the road segment ID and data set in the collection message.

5. The method for implementing an intelligent traffic monitoring and warning system according to any one of claims 1 to 3, characterized in that: The subscription table entry maintained by each edge node contains the driving segment ID, data segment ID, and lifetime. The driving segment refers to the segment ID of the subscribed vehicle's driving segment, and the data segment ID refers to the segment ID of the segment where the traffic accident occurred. The subscription message sent by the vehicle node includes the following information: the real-time coordinates of the current vehicle node, the unique node ID of the local edge node of the current vehicle node, the unique section ID of the current section, and the unique section ID of the target section for which the vehicle node needs to obtain traffic accident data.

6. The method for implementing an intelligent traffic monitoring and warning system according to any one of claims 1 to 3, characterized in that: After receiving the subscription message, the edge node updates or creates a subscription table entry, including: The edge node receiving the subscription message determines whether there is a subscription entry whose driving segment ID and data segment ID are respectively equal to the driving segment ID and data segment ID in the subscription message; If it exists, update the lifetime of the subscription entry to the maximum lifetime; If it does not exist, create a subscription table entry, the driving segment ID and data segment ID of the subscription table entry are respectively equal to the driving segment ID and data segment ID in the subscription message, and the lifetime is equal to the maximum lifetime.

7. The method for implementing an intelligent traffic monitoring and warning system according to any one of claims 1 to 3, characterized in that: The eligible subscription table item is a data segment ID that is equal to the segment ID in the data table item created by the edge node; The warning message sent by the edge node includes the following information: the coordinates of the edge node itself, the node ID of the edge node itself, the data table item created by the edge node, and the driving section ID in the subscription table item that meets the conditions.

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