CN112804661B

CN112804661B - Map data transmission method, system, edge server and storage medium

Info

Publication number: CN112804661B
Application number: CN202110288305.7A
Authority: CN
Inventors: 栗琦; 赵舒怡; 王守荣; 张福磊; 秦景涛; 谷金阳; 肖骁; 徐佳磊; 左子心
Original assignee: Hubei Ecarx Technology Co Ltd
Current assignee: Hubei Ecarx Technology Co Ltd
Priority date: 2021-03-18
Filing date: 2021-03-18
Publication date: 2021-06-29
Anticipated expiration: 2041-03-18
Also published as: CN112804661A; WO2022193511A1

Abstract

In the method, the system, the edge server and the storage medium for transmitting the map data, the vehicle-mounted equipment transmits a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit, the roadside communication unit acquires the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit after receiving the request and transmits the signal intensity to the edge server, the edge server sets the packet size and the data packet transmission frequency according to the signal intensity, divides the map data into a plurality of data packets according to the packet size, and transmits each data packet to the vehicle-mounted subsystem according to the data packet transmission frequency. Because the edge server sets the packet size and the data packet sending frequency based on the signal strength, the influence of the communication quality of a communication channel on map data transmission is reduced, and the efficiency of data packet transmission is ensured as much as possible, so that the vehicle-mounted equipment can obtain map data based on each received data packet, and the efficiency of obtaining the map data by the vehicle is improved.

Description

Map data transmission method, system, edge server and storage medium

Technical Field

The present application relates to the field of intelligent vehicle technologies, and in particular, to a map data transmission method, system, edge server, and storage medium.

Background

The V2X (Vehicle to Vehicle) technology is an internet technology for realizing information interaction between vehicles and the outside world through relevant protocol standards, and includes V2V (Vehicle to Vehicle), V2I (Vehicle to Infrastructure), V2P (Vehicle to Pedestrian), and V2N (Vehicle to internet), and V2X is one of key technologies for realizing automatic driving.

The vehicle acquires map data in time, which is an important factor for realizing automatic driving, and the current scheme for acquiring the map data by the vehicle is mainly as follows: by using the 4G/5G technology, map data is acquired from a cloud server through a Uu interface (an interface in a Wideband Code Division Multiple Access (WCDMA) system). In the process of obtaining map data, a large amount of mobile traffic needs to be consumed, and the map data is easily affected by network signals and network speed, so that the efficiency of obtaining map data by a vehicle is poor.

Disclosure of Invention

An object of the embodiments of the present application is to provide a map data transmission method, a map data transmission system, an edge server, and a storage medium, so as to improve the efficiency of obtaining map data by a vehicle. The specific technical scheme is as follows:

in a first aspect, an embodiment of the present application provides a map data transmission method, including:

the vehicle-mounted equipment sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit;

the roadside communication unit receives the map data distribution request, acquires the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit, and sends the signal intensity to an edge server;

the edge server sets a sub-packet size and a data packet sending frequency according to the signal intensity, divides map data into a plurality of data packets according to the sub-packet size, and transparently transmits each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the data packet sending frequency;

and the vehicle-mounted equipment obtains the map data based on the received data packets.

Optionally, the step of sending the map data distribution request to the roadside communication unit by the vehicle-mounted device through the vehicle-mounted communication unit includes:

when a vehicle provided with the vehicle-mounted equipment enters the operation design domain range of the roadside communication unit, the vehicle-mounted equipment sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit.

the method comprises the steps that vehicle-mounted equipment sends basic safety information to a roadside communication unit through a vehicle-mounted communication unit, wherein a preset flag bit in the basic safety information is set to be a flag value representing that an edge server is requested to distribute map data;

the step of the roadside communication unit receiving the map data distribution request includes:

and the road side communication unit receives the basic safety message, identifies the preset zone bit in the basic safety message, and determines to receive the map data distribution request if the preset zone bit is identified to be set as a zone value representing the map data distribution requested by the edge server.

Optionally, a one-to-many correspondence relationship exists between the edge server and the roadside communication unit;

the step of the roadside communication unit sending the signal strength to an edge server includes:

and the roadside communication unit sends the signal intensity to an edge server corresponding to the roadside communication unit.

Optionally, the step of setting, by the edge server, a packet size and a data packet transmission frequency according to the signal strength includes:

if the signal intensity is smaller than or equal to a first threshold value, the edge server sets the packet size to be a value larger than or equal to a first set value, and sets the data packet sending frequency to be a value larger than or equal to a second set value;

if the signal intensity is larger than the first threshold and smaller than or equal to a second threshold, the edge server sets the packet size to a value smaller than the first set value and larger than or equal to a third set value, and sets the data packet transmission frequency to a value smaller than the second set value and larger than or equal to a fourth set value;

if the signal intensity is larger than the second threshold, the edge server sets the packet size to a value smaller than the third set value, and sets the data packet sending frequency to a value smaller than the fourth set value.

Optionally, the value range of the first threshold is 12-21.5dBm, the value range of the second threshold is 21.5-25dBm, the value range of the first set value is 5-8kB, the value range of the second set value is 50-100Hz, the value range of the third set value is 2-5kB, and the value range of the fourth set value is 10-50 Hz.

Optionally, before the step of transmitting, by the edge server, each data packet to the vehicle-mounted device through the roadside communication unit and the vehicle-mounted communication unit according to the data packet transmission frequency, the method further includes:

the road side communication unit sends packet information to the vehicle-mounted communication unit, wherein the packet information comprises the total number of divided data packets and identification information of each data packet;

the method further comprises the following steps:

and the vehicle-mounted communication unit receives the subpackage information, and if the data packet loss is determined to occur in the process of receiving each data packet based on the subpackage information, a data packet retransmission request is sent to the roadside communication unit to request the roadside communication unit to retransmit the data packet with the data packet loss until all the data packets are successfully received.

Optionally, after the step of receiving the packetization information by the vehicle-mounted communication unit, the method further includes:

the vehicle-mounted communication unit establishes an empty data packet sequence according to the total number of the data packets;

the vehicle-mounted communication unit records the identification information of each data packet into the data packet sequence in sequence;

after the step of transmitting, by the edge server, each data packet to the vehicle-mounted device through the roadside communication unit and the vehicle-mounted communication unit according to the data packet transmission frequency, the method further includes:

the roadside communication unit sends an end message to the vehicle-mounted communication unit;

the step in which the on-vehicle communication unit receives the packetization information, and if it is determined that a packet loss has occurred during reception of each data packet based on the packetization information, transmits a data packet retransmission request to the roadside communication unit, includes:

after receiving the end message, the vehicle-mounted communication unit compares the identification information of the received data packet with the identification information recorded in the data packet sequence, and sends a data packet retransmission request to the roadside communication unit if the identification information of the data packet which is not received exists in the data packet sequence, wherein the data packet retransmission request carries the identification information of the data packet which is not received.

In a second aspect, an embodiment of the present application provides a map data transmission method, including:

the method comprises the steps that an edge server receives signal intensity sent by a roadside communication unit, wherein the signal intensity is obtained by the roadside communication unit after receiving a map data distribution request sent by an on-board communication unit, and is the signal intensity of a communication channel between the roadside communication unit and the on-board communication unit;

the edge server sets the packet size and the data packet sending frequency according to the signal intensity;

the edge server divides the map data into a plurality of data packets according to the packet size;

and the edge server transparently transmits each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the data packet transmission frequency, so that the vehicle-mounted equipment obtains the map data based on each received data packet.

Optionally, the step of setting the packet size and the data packet transmission frequency according to the signal strength includes:

if the signal intensity is smaller than or equal to a first threshold value, setting the packet size to be a value larger than or equal to a first set value, and setting the data packet sending frequency to be a value larger than or equal to a second set value;

if the signal intensity is larger than the first threshold and smaller than or equal to a second threshold, setting the packet size to be a value smaller than the first set value and larger than or equal to a third set value, and setting the data packet sending frequency to be a value smaller than the second set value and larger than or equal to a fourth set value;

if the signal intensity is larger than the second threshold value, setting the packet size to be a value smaller than the third set value, and setting the data packet sending frequency to be a value smaller than the fourth set value.

In a third aspect, an embodiment of the present application provides a map data transmission system, including: a vehicle-mounted end and a roadside end; the vehicle-mounted end comprises vehicle-mounted equipment and a vehicle-mounted communication unit; the roadside end comprises a roadside communication unit and an edge server; the vehicle-mounted communication unit is connected with the roadside communication unit through a communication channel;

the vehicle-mounted equipment is used for sending a map data distribution request to the road side communication unit through the vehicle-mounted communication unit;

the roadside communication unit is used for receiving the map data distribution request, acquiring the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit, and sending the signal intensity to an edge server;

the edge server is used for setting a sub-packet size and a data packet sending frequency according to the signal intensity, dividing map data into a plurality of data packets according to the sub-packet size, and transmitting each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the data packet sending frequency;

and the vehicle-mounted equipment is also used for obtaining the map data based on the received data packets.

In a fourth aspect, an embodiment of the present application provides an edge server, including a processor and a memory;

the memory is used for storing a computer program;

the processor is configured to implement the method according to the second aspect of the embodiment of the present application when executing the computer program stored in the memory.

In a fifth aspect, embodiments of the present application provide a storage medium, in which a computer program is stored, and the computer program, when executed by a processor, implements the method provided in the second aspect of the embodiments of the present application.

In a sixth aspect, embodiments of the present application provide a computer program product comprising instructions, which when run on a computer, cause the computer to perform the method provided by the second aspect of embodiments of the present application.

In the map data transmission method, the system, the edge server and the storage medium provided by the embodiment of the application, the vehicle-mounted device sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit to request the roadside terminal to distribute the map data, the roadside communication unit acquires the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit after receiving the map data distribution request and sends the acquired signal intensity to the edge server, the edge server sets the packet size and the packet sending frequency according to the signal intensity, then divides the map data into a plurality of packets according to the packet size, and sends each packet to the vehicle-mounted subsystem according to the packet sending frequency. The transmission distance between the vehicle-mounted communication unit and the roadside communication unit is short, and the edge server sets the packet size and the data packet sending frequency based on the signal strength, so that the influence of the communication quality of a communication channel on map data transmission is reduced, the efficiency of data packet transmission is ensured as much as possible, and thus, the vehicle-mounted equipment can obtain map data based on the received data packets, and the efficiency of obtaining the map data by the vehicle is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other embodiments can be obtained by using the drawings without creative efforts.

Fig. 1 is a schematic flowchart of a map data transmission method according to an embodiment of the present application;

fig. 2 is a schematic flowchart of another map data transmission method according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a map data transmission system according to an embodiment of the present application;

FIG. 4 is a schematic diagram illustrating an example scenario according to an embodiment of the present application;

FIG. 5 is a schematic diagram of an internal structure of each subsystem of the vehicle-mounted system according to the embodiment of the present application;

FIG. 6 is a schematic flow chart illustrating the internal interaction of the vehicle interconnection system according to the embodiment of the present application;

fig. 7 is a schematic flow chart illustrating specific flow of roadside high-precision map data distribution according to an embodiment of the application;

fig. 8 is a schematic flow chart of transparent transmission of a data packet between the vehicle-mounted device and the roadside device according to the embodiment of the application;

fig. 9 is a schematic structural diagram of an edge server according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the description herein are intended to be within the scope of the present disclosure.

In order to improve the efficiency of obtaining map data by a vehicle, the embodiment of the application provides a map data transmission method, a map data transmission system, an edge server and a storage medium. Next, a map data transmission method provided in the embodiment of the present application is first described.

The map data transmission method provided by the embodiment of the application is applied to a map data transmission system, the system comprises a vehicle-mounted end and a road side end, the vehicle-mounted end comprises vehicle-mounted equipment and a vehicle-mounted communication unit, the road side end comprises a road side communication unit and an edge server, the vehicle-mounted communication unit is connected with the road side communication unit through a communication channel, and data transparent transmission can be achieved between the vehicle-mounted communication unit and the road side communication unit. As shown in fig. 1, the method may include the following steps.

S101, the vehicle-mounted equipment sends a map data distribution request to the road side communication unit through the vehicle-mounted communication unit.

And S102, the roadside communication unit acquires the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit and sends the signal intensity to the edge server.

S103, the edge server sets the packet size and the data packet sending frequency according to the signal intensity.

S104, the edge server divides the map data into a plurality of data packets according to the packet size.

And S105, the edge server transparently transmits each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the data packet transmission frequency.

And S106, the vehicle-mounted equipment obtains map data based on the received data packets.

By applying the scheme of the embodiment of the application, the vehicle-mounted equipment sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit to request the roadside terminal to distribute the map data, the roadside communication unit acquires the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit after receiving the map data distribution request, sends the acquired signal intensity to the edge server, the edge server sets the packet size and the data packet sending frequency according to the signal intensity, then divides the map data into a plurality of data packets according to the packet size, and sends each data packet to the vehicle-mounted subsystem according to the data packet sending frequency. The transmission distance between the vehicle-mounted communication unit and the roadside communication unit is short, and the edge server sets the packet size and the data packet sending frequency based on the signal strength, so that the influence of the communication quality of a communication channel on map data transmission is reduced, the efficiency of data packet transmission is ensured as much as possible, and thus, the vehicle-mounted equipment can obtain map data based on the received data packets, and the efficiency of obtaining the map data by the vehicle is improved.

In the embodiment of the application, the vehicle-mounted end is a general name of a vehicle and equipment (such as vehicle-mounted equipment and a vehicle-mounted communication unit) which is installed on the vehicle and can realize a vehicle automatic driving control function, the road-side end is a general name of equipment which is installed on a road side and assists the vehicle automatic driving, and the road-side end can be composed of traffic lights, a control box, an edge server, a road-side communication unit, a camera, a radar sensor and other equipment and can acquire the driving condition of the vehicle, the dynamic condition of the road and the like in real time.

When the vehicle-mounted equipment has a request for acquiring the map data, for example, when navigation is needed, the vehicle-mounted equipment sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit so as to request the roadside terminal to distribute the map data.

In an implementation manner of the embodiment of the present application, S101 may specifically be: when a vehicle provided with the vehicle-mounted equipment enters the operation design domain range of the roadside communication unit, the vehicle-mounted equipment sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit.

When a vehicle enters into an ODD (Operational Design Domain) range of a roadside communication unit, in order to ensure automatic driving of the vehicle, map data within the ODD range needs to be acquired from a roadside end, and therefore, an on-board device mounted on the vehicle sends a map data distribution request to the roadside communication unit through the on-board communication unit to request the roadside end to distribute the map data.

When a vehicle enters the ODD range of the roadside communication unit, a sensor (such as a camera, a laser radar, a millimeter wave radar and the like) on the roadside detects that the vehicle enters, the sensor sends a reminding message of entering the ODD range to the vehicle-mounted equipment through the roadside communication unit and the vehicle-mounted communication unit, and the vehicle-mounted equipment sends a map data distribution request to the roadside communication unit through the vehicle-mounted communication unit after receiving the reminding message.

The method for sending the map data distribution request to the roadside communication unit by the vehicle-mounted device through the vehicle-mounted communication unit may specifically be: the vehicle-mounted device sends a Basic Safety Message (BSM) to the roadside communication unit through the vehicle-mounted communication unit, a flag bit of a map data distribution request is added in the BSM, when the roadside end is requested to distribute the map data, the flag bit is set to be a preset flag value (for example, 1), after the roadside communication unit receives the BSM, the flag bit is read from the BSM, the flag bit is identified, and if the flag bit is the preset flag value, the vehicle-mounted device is determined to request to distribute the map data.

The vehicle-mounted equipment can also send a custom request message meeting the communication protocol to the roadside communication unit through the vehicle-mounted communication unit so as to request for distributing the map data. The information of the vehicle, such as the identification, the heading angle, the speed, the position, etc. of the vehicle, can also be included in the message of the vehicle-mounted device initiating the request.

After receiving the map data distribution request, the roadside communication unit acquires the signal strength of a communication channel between the roadside communication unit and the vehicle-mounted communication unit. A signal intensity detector can be arranged in the roadside communication unit, and the signal intensity detector can detect the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit through a channel detection technology; of course, the roadside communication unit may also ascertain the time length for the vehicle-mounted communication unit to download data, the transmission distance between the roadside communication unit and the vehicle-mounted communication unit, and whether there is transmission information such as occlusion between the roadside communication unit and the vehicle-mounted communication unit through the communication establishment process with the vehicle-mounted communication unit. Generally, the larger the transmission distance, the more the times of packet loss retransmission are increased, and the longer the time length of downloading data is, so that the signal strength is decreased; on the contrary, the smaller the transmission distance, the less the number of times of packet loss retransmission is performed during transmission, and the shorter the duration of downloading data is, so that the signal strength is higher, and the signal strength is reduced when an obstruction exists. Therefore, further based on these transmission information, the signal strength of the communication channel between the roadside communication unit and the vehicle-mounted communication unit can be calculated. From the analysis, the size of the signal strength can determine the mode of the communication channel for transmitting the map data, so that the roadside communication unit sends the acquired signal strength to the edge server, and the edge server can set the packet size and the data packet sending frequency according to the signal strength, so that the map data distribution can achieve the purposes of rapidness, high efficiency, completeness and reliability as much as possible.

In an implementation manner of the embodiment of the present application, the manner in which the edge server sets the packet size and the data packet transmission frequency may specifically be: if the signal intensity is less than or equal to the first threshold value, setting the packet size to be a value greater than or equal to a first set value, and setting the data packet sending frequency to be a value greater than or equal to a second set value; if the signal intensity is larger than the first threshold and smaller than or equal to the second threshold, setting the packet size to be a value smaller than the first set value and larger than or equal to the third set value, and setting the data packet sending frequency to be a value smaller than the second set value and larger than or equal to the fourth set value; if the signal intensity is larger than the second threshold value, the packet size is set to be a value smaller than a third set value, and the data packet transmission frequency is set to be a value smaller than a fourth set value.

Preferably, the first threshold value ranges from 12 dBm to 21.5dBm (e.g., 15dBm, 19.5dBm, 21 dBm), the second threshold value ranges from 21.5dBm to 25dBm (e.g., 23.5 dBm), the first set value ranges from 5kB to 8kB (e.g., 5kB, 6kB, 7kB, 8 kB), the second set value ranges from 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, 100 Hz), the third set value ranges from 2kB to 5kB (e.g., 2kB, 3kB, 4kB, 5 kB), and the fourth set value ranges from 10Hz to 50Hz (e.g., 10Hz, 20Hz, 30Hz, 40Hz, 50 Hz).

The map data of the edge server is generally acquired from a cloud end and stored locally, the map data distribution request sent by the vehicle-mounted equipment can carry identification information of the required map data, the roadside communication unit can send the identification information to the edge server after receiving the map data distribution request, and the edge server detects the map version according to the identification information and adapts to the map data of the latest version in the ODD range.

After the edge server sets the packet size and the data packet sending frequency, the map data can be divided into a plurality of data packets according to the packet size, specifically, the map data can be compressed, and then the compressed file is divided into a plurality of data packets with the same size according to the packet size, as described above, the size range of the data packets can be 2kB to 8 kB. Then, the edge server transmits each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the set data packet transmission frequency.

After the vehicle-mounted equipment obtains complete map data, data verification and data updating can be carried out through a map data engine of the vehicle, the map data are output to modules of automatic driving path planning and decision, motion control, V2X early warning application, high-precision positioning, visualization and the like, and technical support is carried out on automatic driving.

In the current intelligent traffic management system, a roadside communication unit (RSU) and an on-board communication unit (OBU) communicate in a short-distance communication mode, and can realize functions of vehicle identification, electronic fee deduction, establishment of an unattended vehicle channel and the like. Based on this, in the embodiment of the application, short-distance communication between the vehicle-mounted communication unit and the roadside communication unit is utilized, and the map data is transmitted through a private transparent transmission mode between the vehicle-mounted communication unit and the roadside communication unit, so that the vehicle-mounted end can acquire the required map data from the roadside end without acquiring the map data from the cloud end through a 4G/5G network, and the influence of network signals and network speed on the data acquired from the cloud end is avoided.

The communication channel between the on-vehicle communication unit and the roadside communication unit may be generally established using a PC5 technology or a UWB (Ultra Wide Band) technology, wherein the PC5 technology is a terminal-to-terminal direct communication technology introduced in the D2D (Device-to-Device) Project of 3GPP (3 rd Generation Partnership Project, third Generation technical specification for wireless interface) Rel-12.

In an implementation manner of the embodiment of the present application, there is a one-to-many correspondence between the edge server and the roadside communication unit. S102 may specifically be: and the roadside communication unit sends the signal strength to an edge server corresponding to the roadside communication unit.

The edge server is a local server at the roadside end, and there are generally a plurality of edge servers, each of which is configured to store map data (generally, slice data) of an ODD range managed by a plurality of roadside communication units, that is, there is a one-to-many correspondence relationship between the edge server and the roadside communication units.

In an implementation manner of the embodiment of the present application, before S105, the method may further include: the road side communication unit sends the subpackage information to the vehicle-mounted communication unit, wherein the subpackage information comprises the total number of the divided data packets and the identification information of each data packet;

after S105, the method may further include: and the vehicle-mounted communication unit receives the subpackage information, and if the data packet loss is determined to occur in the process of receiving each data packet based on the subpackage information, the vehicle-mounted communication unit sends a data packet retransmission request to the roadside communication unit so as to request the roadside communication unit to retransmit the data packet with the data packet loss until all the data packets are successfully received.

Because the situation of packet loss of data packets inevitably occurs in the data packet transmission process, in order to ensure the integrity of map data, before transmitting each data packet to the vehicle-mounted communication unit, the roadside communication unit can firstly transmit the packet information comprising the total number of the divided data packets and the identification information of each data packet to the vehicle-mounted communication unit, so that before starting to receive each data packet, the vehicle-mounted communication unit can know how many data packets the roadside communication unit can transmit and know the identification information of each data packet, during the process of receiving each data packet, the vehicle-mounted communication unit can judge whether the situation of packet loss occurs or not based on the packet information, and if the situation of packet loss occurs, the vehicle-mounted communication unit can transmit a data packet retransmission request to the roadside communication unit to request the roadside communication unit to retransmit the data packet in which the packet loss occurs, until all packets are successfully received.

In one implementation manner of the embodiment of the present application, after the step of receiving the packetization information by the vehicle-mounted communication unit, the method may further include: the vehicle-mounted communication unit establishes an empty data packet sequence according to the total number of the data packets; the vehicle-mounted communication unit records the identification information of each data packet into a data packet sequence in sequence;

after S105, the method may further include: the road side communication unit sends an end message to the vehicle-mounted communication unit;

the step of receiving, by the vehicle-mounted communication unit, the packetization information, and if it is determined that packet loss occurs during reception of each data packet based on the packetization information, transmitting a data packet retransmission request to the roadside communication unit may specifically be: after receiving the end message, the vehicle-mounted communication unit compares the identification information of the received data packet with the identification information recorded in the data packet sequence, and if the identification information of the data packet which is not received exists in the data packet sequence, the vehicle-mounted communication unit sends a data packet retransmission request to the road-side communication unit, wherein the data packet retransmission request carries the identification information of the data packet which is not received.

After receiving the packet information, the vehicle-mounted communication unit can establish an empty data packet sequence according to the total number of the data packets, the element number of the data packet sequence is equal to the total number of the data packets, and the vehicle-mounted communication unit sequentially records the identification information of each data packet into the data packet sequence. Correspondingly, after the road-side communication unit transmits each data packet to the vehicle-mounted communication unit, the road-side communication unit also sends an end message to the vehicle-mounted communication unit, so that after receiving the end message, the vehicle-mounted communication unit compares the identification information of the received data packet with the identification information recorded in the data packet sequence, and if the identification information of the data packet which is not received exists in the data packet sequence, the road-side communication unit sends a data packet retransmission request, wherein the data packet retransmission request carries the identification information of the data packet which is not received. And enabling the road side communication unit to retransmit the data packet which is not received by the vehicle-mounted communication unit.

In an implementation manner of the embodiment of the present application, the vehicle-mounted terminal may be composed of a driver's head (i.e., the vehicle-mounted device), a vehicle-mounted communication unit, and a vehicle machine. Specifically, the connection mode of each device at the vehicle-mounted end may be: the vehicle-mounted communication unit is connected with a driving brain and the driving brain is connected with a vehicle machine; or the driving brain is contained in the vehicle-mounted device, and the vehicle-mounted communication unit is connected with the vehicle-mounted device; alternatively, the driver's brain and the in-vehicle communication unit are included in the in-vehicle machine. The driving brain refers to a device with a driving control function on the vehicle, and the vehicle machine refers to a hardware device (e.g., a central control platform of the vehicle) with a human-computer interaction function on the vehicle.

Through the scheme that this application embodiment provided, based on the short distance communication between V2X way side end and the on-vehicle end, realized that the mobile unit obtains map data from the roadside end, need not obtain map data from the high in the clouds through 4G 5G network, avoided obtaining data from the high in the clouds and can receive the influence of network signal and network speed, can save a large amount of Uu mouth flow, realize that low-cost data are issued, promoted the economic benefits that data were issued greatly. And the edge server of the road side end sets the packet size and the data packet sending frequency according to the acquired signal strength, can timely identify the data packet with the packet loss and repeatedly send the data packet with the packet loss, so that the map distribution from the road side end to the vehicle-mounted end can achieve the purposes of rapidness, high efficiency, completeness and reliability, the problem of unstable communication between the road side end and the vehicle-mounted end is effectively solved, and the efficiency of map data distribution can be greatly improved. Experiments show that by using the scheme of the embodiment of the application, the ODD map data with the radius of about 300 meters can be transmitted from the road side end to the vehicle side end within 3 seconds.

The embodiment of the present application further provides a map data transmission method, which is applied to an edge server, as shown in fig. 2, the method may include the following steps.

S201, receiving the signal intensity sent by the roadside communication unit, wherein the signal intensity is the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit, which is acquired by the roadside communication unit after receiving the map data distribution request sent by the vehicle-mounted communication unit.

S202, according to the signal intensity, the packet size and the data packet sending frequency are set.

S203, dividing the map data into a plurality of data packets according to the packet size.

And S204, transparently transmitting each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the data packet transmission frequency, so that the vehicle-mounted equipment obtains the map data based on each received data packet.

By applying the scheme of the embodiment of the application, the roadside communication unit acquires the signal intensity of a communication channel between the roadside communication unit and the vehicle-mounted communication unit after receiving the map data distribution request, and transmits the acquired signal intensity to the edge server, the edge server sets the packet size and the data packet transmission frequency according to the signal intensity, then divides the map data into a plurality of data packets according to the packet size, and transmits each data packet to the vehicle-mounted subsystem according to the data packet transmission frequency. The transmission distance between the vehicle-mounted communication unit and the roadside communication unit is short, and the edge server sets the packet size and the data packet sending frequency based on the signal strength, so that the influence of the communication quality of a communication channel on map data transmission is reduced, the efficiency of data packet transmission is ensured as much as possible, and thus, the vehicle-mounted equipment can obtain map data based on the received data packets, and the efficiency of obtaining the map data by the vehicle is improved.

The size of the signal strength can determine the mode of the communication channel for transmitting the map data, therefore, the roadside communication unit sends the acquired signal strength to the edge server, and the edge server can set the packet size and the data packet sending frequency according to the signal strength, so that the map data distribution can achieve the purposes of rapidness, high efficiency, completeness and reliability as much as possible.

In an implementation manner of the embodiment of the present application, the manner of setting the packet size and the data packet transmission frequency may specifically be: if the signal intensity is less than or equal to the first threshold value, setting the packet size to be a value greater than or equal to a first set value, and setting the data packet sending frequency to be a value greater than or equal to a second set value; if the signal intensity is larger than the first threshold and smaller than or equal to the second threshold, setting the packet size to be a value smaller than the first set value and larger than or equal to the third set value, and setting the data packet sending frequency to be a value smaller than the second set value and larger than or equal to the fourth set value; if the signal intensity is larger than the second threshold value, the packet size is set to be a value smaller than a third set value, and the data packet transmission frequency is set to be a value smaller than a fourth set value.

An embodiment of the present application provides a map data transmission system, as shown in fig. 3, including: a vehicle-mounted end and a road-side end. The vehicle-mounted end comprises a vehicle-mounted device 311 and a vehicle-mounted communication unit 312; the roadside end includes a roadside communication unit 321 and an edge server 322; the vehicle-mounted communication unit 312 and the roadside communication unit 321 are connected by a communication channel.

An in-vehicle device 311 for transmitting a map data distribution request to the roadside communication unit 321 through the in-vehicle communication unit 312;

the roadside communication unit 321 is configured to receive the map data distribution request, acquire the signal strength of a communication channel with the vehicle-mounted communication unit 312, and send the signal strength to the edge server 322;

the edge server 322 is configured to set a packet size and a packet transmission frequency according to the signal strength, divide the map data into a plurality of packets according to the packet size, and transparently transmit each packet to the vehicle-mounted device 311 through the roadside communication unit 321 and the vehicle-mounted communication unit 312 according to the packet transmission frequency;

the in-vehicle device 311 is also configured to obtain map data based on the received data packets.

When the vehicle-mounted device 311 has a request for obtaining map data, for example, when navigation is required, the vehicle-mounted device 311 transmits a map data distribution request to the roadside communication unit 321 through the vehicle-mounted communication unit 312 to request the roadside terminal to distribute the map data.

In an implementation manner of the embodiment of the present application, the vehicle-mounted device 311 may specifically be configured to: when the vehicle in which the vehicle-mounted device 311 is installed enters the operation design domain range of the roadside communication unit 321, the vehicle-mounted device 311 transmits a map data distribution request to the roadside communication unit 321 through the vehicle-mounted communication unit 312.

When the vehicle enters the ODD range of the roadside communication unit 321, in order to ensure automatic driving of the vehicle, the map data within the ODD range needs to be acquired from the roadside end, and therefore, the vehicle-mounted device 311 mounted on the vehicle sends a map data distribution request to the roadside end to request the roadside end to distribute the map data through the vehicle-mounted communication unit 312.

The manner in which the vehicle-mounted device 311 sends the map data distribution request to the roadside communication unit 321 through the vehicle-mounted communication unit 312 may specifically be: the vehicle-mounted device 311 sends a BSM to the roadside communication unit 321 through the vehicle-mounted communication unit 312, the BSM adds a flag bit of a map data distribution request, when a roadside end is requested to distribute map data, the flag bit is set to a preset flag value (for example, 1), after the roadside communication unit 321 receives the BSM, the flag bit is read from the BSM, the flag bit is identified, and if the flag bit is the preset flag value, it is determined that the vehicle-mounted device 311 requests to distribute map data.

After receiving the map data distribution request, the roadside communication unit 321 obtains the signal strength of the communication channel between the roadside communication unit 321 and the vehicle-mounted communication unit 312, and then sends the obtained signal strength to the edge server 322, and the edge server 322 can set the packet size and the data packet sending frequency according to the signal strength, so that the map data distribution is as fast, efficient, complete and reliable as possible.

In an implementation manner of the embodiment of the present application, when the edge server 322 is configured to set the packet size and the packet sending frequency, it may specifically be configured to: if the signal intensity is less than or equal to the first threshold value, setting the packet size to be a value greater than or equal to a first set value, and setting the data packet sending frequency to be a value greater than or equal to a second set value; if the signal intensity is larger than the first threshold and smaller than or equal to the second threshold, setting the packet size to be a value smaller than the first set value and larger than or equal to the third set value, and setting the data packet sending frequency to be a value smaller than the second set value and larger than or equal to the fourth set value; if the signal intensity is larger than the second threshold value, the packet size is set to be a value smaller than a third set value, and the data packet transmission frequency is set to be a value smaller than a fourth set value.

After the edge server 322 sets the packet size and the packet transmission frequency, the map data may be divided into a plurality of packets according to the packet size, specifically, the map data may be compressed, and then the compressed file may be divided into a plurality of packets of the same size according to the packet size, as described above, the size of the packet may range from 2kB to 8 kB. Then, the edge server 322 transparently transmits each data packet to the vehicle-mounted device through the roadside communication unit 321 and the vehicle-mounted communication unit 312 according to the set data packet transmission frequency, that is, the edge server 322 transmits the data packet to the roadside communication unit 321, and the roadside communication unit 321 transparently transmits the data packet to the vehicle-mounted communication unit 312.

After the vehicle-mounted device 311 obtains the complete map data, data verification and data update can be performed through a map data engine of the vehicle, and the map data is output to modules for automatic driving path planning and decision, motion control, V2X early warning application, high-precision positioning, visualization and the like, so that technical support is performed on automatic driving.

The communication channel between the in-vehicle communication unit 312 and the roadside communication unit 321 may be generally established using the PC5 technology or the UWB technology, wherein the PC5 technology is a terminal-to-terminal direct communication technology introduced in the D2D project of 3GPP Rel-12.

In an implementation manner of the embodiment of the present application, there is a one-to-many correspondence between the edge server and the roadside communication unit. Then, when the roadside communication unit is configured to send the signal strength to the edge server, the roadside communication unit may be specifically configured to: and the roadside communication unit sends the signal strength to an edge server corresponding to the roadside communication unit.

In an implementation manner of the embodiment of the present application, the roadside communication unit may be further configured to: transmitting the subpackage information to a vehicle-mounted communication unit, wherein the subpackage information comprises the total number of the divided data packets and identification information of each data packet;

the in-vehicle communication unit may be further configured to: and receiving the subpackage information, if determining that the data packet loss occurs in the process of receiving each data packet based on the subpackage information, sending a data packet retransmission request to the roadside communication unit to request the roadside communication unit to retransmit the data packet with the data packet loss until all the data packets are successfully received.

Since packet loss of data packets inevitably occurs during data packet transmission, in order to ensure integrity of map data, before transmitting each data packet to the vehicle-mounted communication unit 312, the roadside communication unit 321 may first transmit packet information including the total number of divided data packets and identification information of each data packet to the vehicle-mounted communication unit 312, so that before the vehicle-mounted communication unit 312 starts receiving each data packet, it can know how many data packets the roadside communication unit 321 transmits, and know identification information of each data packet, during receiving each data packet, the vehicle-mounted communication unit 312 can determine whether packet loss occurs based on the packet information, and if it is determined that packet loss occurs, can transmit a data packet retransmission request to the roadside communication unit 321 to request the roadside communication unit 321 to retransmit the data packet in which packet loss occurs, until all packets are successfully received.

In an implementation manner of the embodiment of the present application, the vehicle-mounted communication unit may be further configured to: establishing an empty data packet sequence according to the total number of the data packets; the vehicle-mounted communication unit records the identification information of each data packet into a data packet sequence in sequence;

the roadside communication unit may be further to: sending an end message to the vehicle-mounted communication unit;

the vehicle-mounted communication unit is configured to receive the packetization information, and when determining that a packet loss occurs during reception of each data packet based on the packetization information, and sending a data packet retransmission request to the roadside communication unit, specifically, may be configured to: after receiving the end message, comparing the identification information of the received data packet with the identification information recorded in the data packet sequence, and if the identification information of the data packet which is not received exists in the data packet sequence, sending a data packet retransmission request to the road side communication unit, wherein the data packet retransmission request carries the identification information of the data packet which is not received.

After receiving the packetization information, the vehicle-mounted communication unit 312 may establish an empty data packet sequence according to the total number of the data packets, where the number of elements of the data packet sequence is equal to the total number of the data packets, and the vehicle-mounted communication unit 312 sequentially records the identification information of each data packet into the data packet sequence. Accordingly, after the roadside communication unit 321 transparently transmits each data packet to the vehicle-mounted communication unit 312, the roadside communication unit 321 may further send an end message to the vehicle-mounted communication unit 312, so that after receiving the end message, the vehicle-mounted communication unit 312 compares the identification information of the received data packet with the identification information recorded in the data packet sequence, and if the identification information of the data packet that is not received exists in the data packet sequence, sends a data packet retransmission request to the roadside communication unit 321, where the data packet retransmission request carries the identification information of the data packet that is not received. So that the roadside communication unit 321 retransmits the data packet which is not received by the vehicle-mounted communication unit 312.

For convenience of understanding, the map data transmission method provided in the embodiment of the present application is described below with reference to a specific system example.

As shown in fig. 4, which is a scene schematic diagram of a specific example of the embodiment of the present application, before map data is issued, a vehicle-to-vehicle system in a vehicle-road-cloud integrated V2X environment needs to be established according to the requirements of the scene, and the vehicle-to-vehicle system is divided into a cloud platform subsystem, a vehicle-mounted subsystem, and a road side subsystem.

Data transmission is carried out between the vehicle-mounted subsystem and the road side subsystem through a PC5 interface, and the main function is to transmit map data. And the vehicle-mounted subsystem carries out data butt joint with the cloud platform subsystem through the 4G of the Uu port, and acquires dynamic traffic data from the cloud platform subsystem through the Uu port. And the road side subsystem carries out data butt joint with the cloud platform subsystem through the optical fiber/wired Ethernet, and acquires map data and dynamic traffic data from the cloud platform subsystem. The cloud platform subsystem can also perform data interaction with a third party platform through an optical fiber/wired Ethernet.

The internal structure of each subsystem of the train communication system is shown in fig. 5, and the road side subsystem mainly comprises an RSU (namely, the road side communication unit), an edge server and a road side sensing device, and performs data interaction with the cloud platform subsystem through an optical fiber switch. The vehicle-mounted subsystem mainly comprises an OBU (i.e., the vehicle-mounted communication unit), a driver head (i.e., the vehicle-mounted device), and a vehicle machine (HMI and Pad vehicle end visualization module in fig. 5). The cloud platform subsystem mainly comprises a database and a cloud platform server, the cloud platform server is a V2X server in the temporary test field stage, has a digital twin function, and performs data interaction with the road side subsystem through the optical fiber switch.

Roadside perception equipment includes camera, lidar, millimeter wave radar and marginal computing equipment etc. and equipment such as camera, lidar, millimeter wave radar are through deploying on-the-spot, realize the original information perception to traffic system, and then through marginal computing power, handle data, form local perception and statistical result, support roadside wisdom and use.

The internal interaction process of the vehicle-mounted system is shown in fig. 6, a third-party platform and a cloud platform subsystem perform data interaction, a data accommodating module of the cloud platform subsystem stores active map data, an automatic driving data production module obtains an AD map data production library according to the source map data and dynamic traffic data, then an online compiling module performs data compiling and data publishing to obtain an AD map data publishing library, a data distribution service module transmits map data information to a roadside subsystem through approval and publishing of a data publishing unit through data preparation, data query and data extraction processes, after the roadside subsystem receives the map data information, an edge server in the roadside subsystem performs version polling check, if the cloud platform subsystem finds that the map data is updated, a version update request message is transmitted to the cloud platform subsystem to obtain the updated map data from the cloud platform subsystem, and stored in a local AD map database. And the edge server can form data such as local perception and statistical result according to the data that trackside perception equipment gathered for support trackside wisdom is used for.

When a vehicle provided with an OBU drives into an electronic fence of the RSU, a driver sends a request message to the RSU through the OBU through a PC5 channel, the RSU transmits the request message to an edge server, a data distribution service module in the edge server receives the request message, map data are transmitted back to the RSU through data query and data release, a transparent transmission mode is achieved between the RSU and the OBU, and the RSU sends the map data to the OBU. And the router in the vehicle-mounted subsystem can also request dynamic traffic data from the cloud platform server through the Uu interface, the router and the OBU respectively send the acquired data to the driver's brain, and the driver's brain performs operations such as data fusion and a map data engine to realize vehicle-mounted applications such as visualization, V2X early warning application, high-precision positioning, path planning and decision making, motion control and the like.

The specific flow of roadside high-precision map data distribution is shown in fig. 7, when a vehicle enters an electronic fence of an RSU, a driver generates a request message, where the request message includes information of the vehicle, such as identification information, heading angle, speed, position, and the like of the vehicle; the method comprises the steps that a request message is transmitted to an RSU through an OBU, the RSU transmits the request message to an edge server, the edge server conducts data query, map block numbers and the number of the map blocks are returned to the OBU through the RSU, and the OBU transmits the map block numbers and the number of the map blocks to a driver's brain, wherein the source of the data query conducted by the edge server comprises map data sent by a cloud and data obtained by data construction conducted by a roadside sensing device through a data return edge server, and the map data sent by the cloud is mainly obtained through the steps of determining an ODD range and releasing AD map data; the driver brain requests a corresponding specific map block from the RSU through the OBU, and after receiving the specific request, the edge terminal equipment sets the packet size and the data packet sending frequency according to the signal intensity; dividing map data into a plurality of data packets with the same size according to the packet size, then starting a data downloading service, wherein the data downloading service is to transparently transmit each data packet to an OBU (on-board unit) through an RSU (remote subscriber unit) according to the data packet transmitting frequency, receive each data packet from the OBU by a driver, then perform data verification and decompression operation, then start a data updating service, multiplex Uu port data updating, perform tracing automatic driving and avoiding driving/stopping based on the updated map data, and perform abnormal condition processing or perform breakpoint retransmission operation if an abnormal condition is met.

Fig. 8 shows a process of transparently transmitting a data packet between an RSU and an OBU, which includes the following steps:

1. the OBU requests the downloading of map data of a specific map tile, sending a REQ (request message) to the RSU.

2. And after receiving the REQ, the RSU sends basic information FILEMSG corresponding to the map information of the applied map block to the OBU, if the ACK (feedback message) is not received in k seconds, the RSU retransmits the map information, and exits after retransmitting for 2 times at most, wherein the FILEMSG comprises the file size, the packet total number and the like.

3. And after the OBU receives the FILEMSG, a blank file is newly established for receiving the data packet, a packet loss sequence is established according to the total number of the sub-packets to confirm the serial number of the packet loss, and ACK _ FILEMSG is returned to the RSU.

4. The RSU transmits all packets of map data to the OBU at once and transmits a FILEEND indicating that the transmission is completed.

5. And after receiving the FILEND, the OBU checks a packet loss sequence, whether a data packet which is not received exists or not, if not, the OBU returns ACK _ FILEND, and the OBU finishes communication or sends a new REQ. And if the data packet is not received, sending ACK _ RESEND to request to retransmit the corresponding data packet.

6. And the RSU sends the RESEND with the corresponding data packet according to the data packet number of the ACK _ RESEND request. If the OBU does not receive RESEND after timeout, it retransmits at most 2 times.

7. And after receiving the RESEND, the OBU checks the packet loss sequence again, if the packet loss exists, sends ACK _ RESEND, and if the packet loss does not exist, sends ACK _ END and ENDs.

8. And the RSU receives the ACD _ END and finishes the transmission.

An embodiment of the present application further provides an edge server, as shown in fig. 9, including a processor 901 and a memory 902, where the memory 902 is used for storing a computer program; the processor 901 is configured to implement the above-described map data transmission method applied to the edge server when executing the computer program stored in the memory 902.

The Memory may include a RAM (Random Access Memory) or an NVM (Non-volatile Memory), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the processor.

The Processor may be a general-purpose Processor including a CPU (Central Processing Unit), an NP (Network Processor), and the like; but also a DSP (Digital Signal Processing), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component.

In this embodiment, the processor reads the computer program stored in the memory and runs the computer program, so as to implement: the road side communication unit acquires the signal intensity of a communication channel between the road side communication unit and the vehicle-mounted communication unit after receiving the map data distribution request, and transmits the acquired signal intensity to the edge server, the edge server sets the sub-packet size and the data packet transmission frequency according to the signal intensity, then divides the map data into a plurality of data packets according to the sub-packet size, and transmits each data packet to the vehicle-mounted subsystem according to the data packet transmission frequency. The transmission distance between the vehicle-mounted communication unit and the roadside communication unit is short, and the edge server sets the packet size and the data packet sending frequency based on the signal strength, so that the influence of the communication quality of a communication channel on map data transmission is reduced, the efficiency of data packet transmission is ensured as much as possible, and thus, the vehicle-mounted equipment can obtain map data based on the received data packets, and the efficiency of obtaining the map data by the vehicle is improved.

In addition, an embodiment of the present invention provides a storage medium, where a computer program is stored in the storage medium, and when the computer program is executed by a processor, the map data transmission method applied to an edge server is implemented.

In this embodiment, the computer-readable storage medium stores a computer program that executes the map data transmission method applied to the edge server provided in the embodiment of the present invention when executed, and thus can implement: the road side communication unit acquires the signal intensity of a communication channel between the road side communication unit and the vehicle-mounted communication unit after receiving the map data distribution request, and transmits the acquired signal intensity to the edge server, the edge server sets the sub-packet size and the data packet transmission frequency according to the signal intensity, then divides the map data into a plurality of data packets according to the sub-packet size, and transmits each data packet to the vehicle-mounted subsystem according to the data packet transmission frequency. The transmission distance between the vehicle-mounted communication unit and the roadside communication unit is short, and the edge server sets the packet size and the data packet sending frequency based on the signal strength, so that the influence of the communication quality of a communication channel on map data transmission is reduced, the efficiency of data packet transmission is ensured as much as possible, and thus, the vehicle-mounted equipment can obtain map data based on the received data packets, and the efficiency of obtaining the map data by the vehicle is improved.

In still another embodiment, a computer program product containing instructions is provided, which when run on a computer, causes the computer to execute the above map data transmission method applied to an edge server.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber, DSL (Digital Subscriber Line)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy Disk, a hard Disk, a magnetic tape), an optical medium (e.g., a DVD (Digital Versatile Disk)), or a semiconductor medium (e.g., a SSD (Solid State Disk)), etc.

As for the embodiments of the edge server, the storage medium and the computer program product, since the contents of the related methods are substantially similar to those of the foregoing embodiments of the map data transmission method applied to the edge server, the description is relatively simple, and the relevant points can be referred to the partial description of the embodiments of the methods.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments.

The above description is only for the preferred embodiment of the present application and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A map data transmission method, comprising:

the edge server sets a sub-packet size and a data packet sending frequency according to the signal intensity, compresses map data, divides the compressed map data into a plurality of data packets according to the sub-packet size, and transparently transmits each data packet to the vehicle-mounted equipment through the roadside communication unit and the vehicle-mounted communication unit according to the data packet sending frequency;

in the process of receiving each data packet, if the vehicle-mounted communication unit judges that packet loss occurs, sending a data packet retransmission request to the roadside communication unit, and retransmitting the packet-lost data packet to the vehicle-mounted communication unit by the roadside communication unit;

2. The method according to claim 1, wherein the step of the vehicle-mounted device transmitting the map data distribution request to the roadside communication unit through the vehicle-mounted communication unit includes:

3. The method according to claim 1 or 2, wherein the step of the vehicle-mounted device transmitting the map data distribution request to the roadside communication unit through the vehicle-mounted communication unit includes:

4. The method of claim 1, wherein there is a one-to-many correspondence between the edge server and the roadside communication unit;

5. The method of claim 1, wherein the step of the edge server setting the packet size and the packet transmission frequency according to the signal strength comprises:

6. The method of claim 5, wherein the first threshold value ranges from 12 dBm to 21.5dBm, the second threshold value ranges from 21.5dBm to 25dBm, the first set value ranges from 5kB to 8kB, the second set value ranges from 50Hz to 100Hz, the third set value ranges from 2kB to 5kB, and the fourth set value ranges from 10Hz to 50 Hz.

7. The method of claim 1, wherein before the step of the edge server transparently transmitting each data packet to the vehicle-mounted device through the roadside communication unit and the vehicle-mounted communication unit according to the data packet transmission frequency, the method further comprises:

the method further comprises the following steps:

8. The method according to claim 7, wherein after the step of the vehicle-mounted communication unit receiving the packetization information, the method further comprises:

9. A map data transmission method, comprising:

the edge server compresses the map data, and divides the compressed map data into a plurality of data packets according to the packet size;

the edge server transparently transmits each data packet to the vehicle-mounted equipment through the road side communication unit and the vehicle-mounted communication unit according to the data packet transmitting frequency, so that the vehicle-mounted equipment obtains the map data based on each received data packet; in the process of receiving each data packet, if the vehicle-mounted communication unit judges that packet loss occurs, the vehicle-mounted communication unit sends a data packet retransmission request to the roadside communication unit, and the roadside communication unit retransmits the packet-lost data packet to the vehicle-mounted communication unit.

10. The method of claim 9, wherein the step of setting the packet size and the packet transmission frequency according to the signal strength comprises:

11. The method of claim 10, wherein the first threshold value ranges from 12 dBm to 21.5dBm, the second threshold value ranges from 21.5dBm to 25dBm, the first set value ranges from 5kB to 8kB, the second set value ranges from 50Hz to 100Hz, the third set value ranges from 2kB to 5kB, and the fourth set value ranges from 10Hz to 50 Hz.

12. A map data transmission system, comprising: a vehicle-mounted end and a roadside end; the vehicle-mounted end comprises vehicle-mounted equipment and a vehicle-mounted communication unit; the roadside end comprises a roadside communication unit and an edge server; the vehicle-mounted communication unit is connected with the roadside communication unit through a communication channel;

the edge server is used for setting a sub-packet size and a data packet sending frequency according to the signal intensity, compressing the map data, dividing the compressed map data into a plurality of data packets according to the sub-packet size, and transmitting each data packet to the vehicle-mounted equipment through the roadside communication unit and the vehicle-mounted communication unit according to the data packet sending frequency;

the vehicle-mounted communication unit is used for sending a data packet retransmission request to the road side communication unit if the condition of packet loss is judged to occur in the process of receiving each data packet;

the roadside communication unit is further used for retransmitting a packet-lost data packet to the vehicle-mounted communication unit;

13. An edge server comprising a processor and a memory;

the memory is used for storing a computer program;

the processor, when executing the computer program stored on the memory, implementing the method of any of claims 9-11.

14. A storage medium, characterized in that the storage medium has stored therein a computer program which, when being executed by a processor, carries out the method according to any one of claims 9-11.