CN111757280B

CN111757280B - Perception base station in road traffic environment and message sending control method and device thereof

Info

Publication number: CN111757280B
Application number: CN201910239497.5A
Authority: CN
Inventors: 单单; 陈颖
Original assignee: Alibaba Group Holding Ltd
Current assignee: Wuzhou Online E Commerce Beijing Co ltd
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2022-05-17
Anticipated expiration: 2039-03-27
Also published as: CN111757280A

Abstract

The embodiment of the application discloses a perception base station in a road traffic environment and a method and a device for controlling message sending of the perception base station, wherein the perception base station comprises: the message classification module is used for obtaining at least one message to be sent, determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message, adding the first type of message into a first message queue, triggering the sending of the first type of message, and adding the second type of message into a second message queue; and the time division multiplexing TDMA control module is used for acquiring a time service signal and time slot resource information distributed for the associated perception base station, and when the time slot arrives, reading a second type of message from the second message queue and triggering the sending of the second type of message. By the embodiment of the application, various types of messages can be delivered to the receiver more timely and reliably.

Description

Perception base station in road traffic environment and message sending control method and device thereof

Technical Field

The application relates to the technical field of vehicle-road cooperation, in particular to a perception base station in a road traffic environment and a message sending control method and device thereof.

Background

In the fields of automatic driving, intelligent transportation and the like, a highly intelligent automatic driving vehicle can effectively sense the surrounding environment, acquire the information of the type, position, direction, size, speed and the like of nearby targets, and make a reasonable driving decision by combining the driving state of the vehicle to complete the driving of the vehicle, so that the manual driving labor is replaced, and the highly automatic driving process is realized.

Currently, there are two main types of automatic driving sensing systems: and vehicle-mounted sensor network perception and vehicle road cooperative perception. Under the mode of vehicle-mounted sensor network perception, the automatic driving automobile needs to be provided with numerous autonomous sensors (laser radar, millimeter wave radar, cameras and the like) to acquire enough abundant and diversified sensing information, and is matched with powerful computing equipment to process data rapidly in real time to acquire a complete perception result. However, due to the limitation caused by the low visual angle of the vehicle, the vehicle is in various traffic driving environments, and the sensing process of the vehicle is not enough and is difficult to complete a comprehensive sensing function. In addition, this method has a great dependence on the vehicle's own sensor system, and if a fault occurs, it has a great influence on the safety of automatic driving.

In the Vehicle-Road cooperative sensing system, a sensing base station performs information interaction with an On-Board Unit (OBU) mounted On a nearby Vehicle through an RSU (Road Side Unit) in a V2X (Vehicle to evolution) system, so as to realize a plurality of applications such as advanced driving assistance and intelligent transportation. In this way, the requirements for the assembly condition and the calculation capability of the sensor of the vehicle can be reduced, and therefore, the method has a wider application prospect.

In order to meet the requirements of various applications, the sensing base station can acquire information through various means such as sensing, communication and the like, encapsulate the information into messages and broadcast the messages through the RSU. The sensing means of the sensing base station mainly comprises the steps of acquiring data of sensors such as a camera, a millimeter wave radar and a laser radar, processing the data in a computing unit through an image or signal processing algorithm, and finally acquiring information of roads and traffic participants, such as lane line coordinates, positions and speeds of vehicles and pedestrians. The communication means of the base station mainly includes acquiring information such as road information, information of traffic participants, weather, emergency notification, and the like from wireless communication devices such as V2X, Wi-Fi, a mobile communication network (e.g., 4G), and the like, and wired communication devices such as an optical fiber, an ethernet, and the like. The information is encapsulated into a message that is sent to the recipient via the RSU.

In the prior art, the sensing base station has the same sending or forwarding mode for the messages carrying various types of information, so that the situation that the emergency message cannot reach the receiver (including traffic participants on the road) timely or effectively may occur, and the corresponding driving decision cannot be made timely, which may cause an accident.

Therefore, how to make various types of messages reach the receiver more timely and reliably becomes a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The application provides a perception base station in a road traffic environment and a message sending control method and device thereof, which can enable various types of messages to be sent to a receiver more timely and reliably.

The application provides the following scheme:

a perception base station in a road traffic environment, comprising:

the message classification module is used for obtaining at least one message to be sent, determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message, adding the first type of message into a first message queue, triggering the sending of the first type of message, and adding the second type of message into a second message queue;

and the time division multiplexing TDMA control module is used for acquiring a time service signal and time slot resource information distributed for the associated perception base station, and when the time slot arrives, reading a second type of message from the second message queue and triggering the sending of the second type of message.

A message sending control method in a perception base station comprises the following steps:

obtaining at least one message to be sent, and determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message;

adding a first type of message into a first message queue and triggering the sending of the first type of message;

adding the second type of message to a second message queue;

and acquiring a time service signal and time slot resource information distributed for the associated perception base station, and when a time slot arrives, reading a second type of message from the second message queue and triggering the sending of the second type of message.

A method of message generation in a road traffic environment, comprising:

the perception base station obtains information in a road traffic environment;

determining the urgency degree of the information according to the information type, the action and/or the scene information of the information;

and writing the information of the degree of urgency into a corresponding field in a preset message structure body to generate a message so as to determine a sending strategy of the message according to the degree of urgency.

A message structure is disclosed, which is composed of a message structure,

the message is sent through a perception base station in the intelligent traffic system;

the message structure body comprises a first type message or a second type message mark field, and is used for carrying out trigger type sending on the first type message according to the emergency degree of the message and sending on the second type message according to a time division multiplexing protocol; wherein the triggered sending is: and sending the first type of message after the first type of message is generated, wherein the sending according to a time division multiplexing protocol comprises the following steps: and transmitting the time slot after the time slot of the perception base station is allocated.

A message transmission control apparatus in a cognitive base station, comprising:

the message obtaining unit is used for obtaining at least one message to be sent and determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message;

the first sending trigger unit is used for adding the first type of messages into a first message queue and triggering the sending of the first type of messages;

the queue adding unit is used for adding the second type of message into a second message queue;

and the second sending triggering unit is used for acquiring the time service signal and the time slot resource information distributed for the associated sensing base station, and when the time slot arrives, the sending of the second type of message is triggered after the second type of message is read from the second message queue.

A message generating device in a road traffic environment is applied to a perception base station and comprises:

an information obtaining unit for obtaining information in a road traffic environment;

the emergency degree determining unit is used for determining the emergency degree of the information according to the information type, the action and/or the scene information of the information;

and the message generating unit is used for writing the information of the emergency degree into a corresponding field in a preset message structure body to generate a message so as to determine a sending strategy of the message according to the emergency degree.

According to the specific embodiments provided herein, the present application discloses the following technical effects:

according to the embodiment of the application, the relevant fields are added in the message structure body and used for indicating whether the message belongs to the first type message or the second type message (for example, an urgent message or a non-urgent message), so that the first type message and the second type message can be sent according to different strategies for the sensing base station which needs to send or forward the message. Wherein, the first type message can be sent in time without waiting for the arrival of the time slot. And for the second type of message, the message needs to wait for the arrival of a specific time slot before being sent. Therefore, the first type of message can be sent out in a triggering mode, and the minimum time delay is ensured. Meanwhile, the second type of messages can be periodically sent out in the preassigned time slot, and the packet loss rate is reduced on the whole.

In addition, in a preferred implementation, an arbitration module may be provided to which messages of the first type may be sent once they have been generated or received, and to which messages of the second type may also be sent by the TDMA control module after a particular acquisition time slot. Therefore, if the first type message and the second type message in the same sensing base station arrive at the same time, the first type message can be preferentially sent, and after the first type message is sent, the second type message is sent again if the time slot is not finished. Therefore, the first-class messages are further preferentially sent, and the time slot resources used by the first-class messages and the second-class messages do not conflict with each other, so that the probability of packet loss is reduced.

Furthermore, in a preferred implementation manner, after each sensing base station obtains a time slot, specifically, when sending a message, some time slot resources may be reserved instead of occupying all the time slots, so that the first type of message generated by adjacent sensing base stations from time to time is used, thereby reducing the mutual interference between adjacent sensing base stations, and further reducing the packet loss rate.

Of course, it is not necessary for any product to achieve all of the above-described advantages at the same time for the practice of the present application.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments 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 to obtain other drawings without creative efforts.

Fig. 1 is a schematic diagram of a road and a cognitive base station deployment scenario provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a cognitive base station provided in an embodiment of the present application;

fig. 3 is a schematic diagram of a time slot resource reservation scheme provided in an embodiment of the present application;

FIG. 4 is a flow chart of a first method provided by an embodiment of the present application;

FIG. 5 is a flow chart of a second method provided by embodiments of the present application;

FIG. 6 is a schematic diagram of a first apparatus provided by an embodiment of the present application;

fig. 7 is a schematic diagram of a second apparatus provided in 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 from the embodiments given herein by a person of ordinary skill in the art are intended to be within the scope of the present disclosure.

For convenience of understanding, the deployment of the cognitive base station related to the embodiments of the present application and the message sending manner of the cognitive base station in the prior art are first described.

In the vehicle-road cooperative system, the sensing result of the sensing base station is broadcast to nearby vehicles through the RSU in the V2X system. The sensing results mainly comprise information of positions, speeds and the like of traffic participants such as pedestrians, vehicles and the like, and the information is packaged in a message. After the vehicle receives the messages through the OBU, the danger in the driving process can be predicted in advance, and actions such as alarming, automatic emergency braking and the like are taken to deal with the dangers. The sensing range of a single sensing base station is limited, and in order to cover all areas of a road in an all-around dead-angle-free manner, a plurality of base stations can be continuously deployed on two sides of the road according to respective sensing distances, sense different sections of the road simultaneously, and broadcast messages carrying sensing results respectively through respective RSUs. The spacing between base stations is typically approximately equal to twice the perceived distance. Since the effective communication distance (about 500 meters) of the V2X system is usually greater than twice the sensing distance (within 200 meters), the RSU can not only receive the messages broadcast by the nearby OBUs, but also receive the messages from the adjacent RSUs, and a plurality of RSUs form a V2X network. For example, as shown in fig. 1, the messages broadcast by RSU a can be received by

vehicles

101, 102, 103, etc., while RSU a can also receive the messages broadcast by RSU B. Similarly, the messages broadcast by RSU B can be received by vehicles 104, etc., while RSU B can also receive the messages broadcast by RSU a. However, adjacent RSUs need to share the same communication channel by means of a mac (medium Access control) layer protocol, otherwise, the adjacent RSUs may interfere with each other.

Common MAC layer protocols include Time Division Multiplexing (TDMA), frequency division multiplexing (FMDA), Carrier Sense Multiple Access (CSMA), and the like. The principle of time division multiplexing is that different communication devices respectively send messages in the same frequency band at different appointed time; its advantages are high utilization rate of frequency spectrum, low complexity and time synchronization between communication devices. The principle of frequency division multiplexing is that different communication devices respectively send messages in different appointed frequency bands at the same time; its advantages are low complexity and low utilization rate of frequency spectrum. The principle of CSMA is that different communication devices randomly send messages in a competitive mode, and the CSMA has the advantages of high spectrum utilization rate, high complexity, hardware support and increased packet loss rate in the networking process.

Since the V2X devices (including OBUs and RSUs) are usually installed with Global Navigation Satellite Systems (GNSS), time synchronization among multiple devices can be conveniently realized, and therefore, it is reasonable to adopt TDMA as the MAC layer protocol.

When multiple base station-aware RSUs share a channel using a TDMA protocol, each RSU typically transmits messages in predefined time segments, referred to as time slots, that are evenly distributed in time to ensure that the messages transmitted by itself do not collide with any other RSU transmitted messages. Thus, regardless of how the messages generated by the base station are distributed in time, they must be sent out periodically; in other words, the message generated by the base station must wait for the time slot allocated to itself to arrive before being transmitted. For example, the time length of each timeslot is T ═ 10ms, and since RSUs that may interfere with each other usually occur between three adjacent RSUs, only time slot allocation needs to be performed between the three RSUs. For example, the 0 th to 10 th ms is allocated to the equipment A, the 10 th to 20 th ms is allocated to the equipment B, the 20 th to 30 th ms is allocated to the equipment C, the 30 th to 40 th ms is allocated to the equipment A, the 40 th to 50 th ms is allocated to the equipment B, and the like. That is, the same device will not acquire a slot after every 30 ms.

However, in practical applications, the urgency level of the message to be sent in the base station may also be different according to the type of information carried in the message. For example, a message carrying road congestion information, defects such as potholes and water accumulation on the road surface, road repair and closing information, average vehicle speed, and other information generally requires an end-to-end delay of within 1 second; messages carrying information about traffic participants such as the position, orientation and speed of pedestrians, motor vehicles, bicycles, the phase of traffic lights, and stationary obstacles left on the road surface typically require an end-to-end delay of within 100 milliseconds, with the smaller the better.

In the prior art, when a base station sends a message, the emergency degree of the message is not distinguished, and the message is sent in the same manner. However, when the TDMA protocol is used, the timeliness of the transmission of the emergency message may be affected. For example, assuming that the interval between the slots allocated to an RSU is equal to T, the latency W of each message generated by the RSU is evenly distributed between 0 and T. T100 ms is the time interval commonly used by V2X systems, which means that the latency is equal to 100 ms in the worst case, and 50ms on average; since the transmission of data is also time consuming and the delay is equal to the latency plus the transmission time, the worst case delay is over 100 ms, so that the requirement of low delay for urgent messages cannot be met.

However, if the urgent message is directly transmitted without waiting for the pre-allocated time slot to arrive, it may collide with the message transmitted by the adjacent RSU, thereby increasing the packet loss rate. For example, the RSU a and the RSU B generate a message at the same time at a certain time, and both the RSU a and the RSU B directly transmit the message in a random transmission manner, but contend for the same spectrum resource may be generated, thereby causing packet loss. And failure of the urgent message to be correctly received by the recipient is a more unacceptable result than delaying the urgent message by 100 milliseconds. Experiments show that the packet loss rate of randomly sent messages may be 10 times of the packet loss rate of messages sent according to time slots.

Therefore, in the prior art, if the message is directly sent through protocols such as CSMA and the like, the emergency message may not be sent out in time, and the effective receiving opportunity of the message is delayed; if the random transmission mode is directly adopted, a relatively high packet loss rate may be generated.

Therefore, the embodiment of the present application improves the message sending method of the cognitive base station in view of the above situation. In an improved scheme, messages to be sent in the cognitive base station can be divided into two types, namely messages of a first type and messages of a second type. When the message is specifically implemented, the first type of message may be called an urgent message, and the second type of message may be called a non-urgent message. For ease of description and understanding, messages of the first type/urgent messages, and messages of the second type/non-urgent messages, may be alternated. Of course, in practical applications, the first type message and the second type message may also have other specific naming manners, and this should not be considered as a limitation to the embodiments of the present application.

Wherein, for urgent message, it can be directly transmitted after being generated, and for non-urgent message, it can be transmitted by TDMA mode until the specific time slot comes. The advantage of carrying out the layered sending in this way is that, on one hand, the emergency message can be sent at any time without waiting for the arrival of the time slot, and the timeliness of the sending is ensured; on the other hand, the method is convenient to control for some situations where collision may occur, and the problem of high packet loss rate caused by transmission at any time is solved. Specifically, one of the situations that a collision may occur is that when an urgent message is generated or received in a base station, the urgent message is guaranteed to be preferentially sent within a time slot range obtained by the base station through an arbitration mechanism, and after the urgent message is sent, if the urgent message is still located in the time slot, the non-urgent message is sent, otherwise, the non-urgent message may be put back into a non-urgent message queue to wait for the next time slot to arrive. Another situation where a collision may occur is that when an urgent message is generated or received in a base station, the urgent message is just within the range of a time slot acquired by another adjacent base station, and for this situation, each base station may not fully occupy the time slot after acquiring the time slot, that is, when a non-urgent message is transmitted in the time slot, some time intervals may be reserved between each message, so that a fragment of the time slot is reserved, which may be used for urgent messages arriving from other adjacent base stations at different times, thereby reducing the probability that the urgent message collides with the non-urgent message transmitted in the base station that is acquiring the time slot. The specific ratio of the reserved time slot resources may be determined according to the quantity ratio of the urgent messages to the non-urgent messages, for example, the ratio of the reserved time slot resources may be greater than the ratio of the urgent messages to all messages, so as to reduce the probability of the urgent messages being interfered, and further reduce the packet loss rate. Therefore, by the mode, the situation that the packet loss rate is increased can be avoided under the condition that the emergency message can be sent more timely, so that the message can be sent to the receiving equipment more timely and reliably.

The following describes in detail specific implementations provided in embodiments of the present application.

Example one

The first embodiment provides a sensing base station in an intelligent transportation system, and referring to fig. 2, the sensing base station may specifically include:

a message classification module 201, configured to obtain at least one message to be sent, determine that the message belongs to a first type of message or a second type of message according to a target field included in the message, add the first type of message to a first message queue, trigger sending of the first type of message, and add the second type of message to a second message queue;

and the time division multiplexing TDMA control module 202 is configured to obtain a time service signal and time slot resource information allocated to an associated sensing base station, and when a time slot arrives, read a second type of message from the second message queue and then trigger sending of the second type of message.

The message to be sent can be generated according to the obtained information, wherein the information can be from multiple sources, one of the multiple sources can be information locally generated by the sensing base station, and the other one can be allopatric information. The local information generation module is mainly used for obtaining local information from raw data of sensors such as a camera, a millimeter wave radar and a laser radar through image processing or signal processing algorithm calculation. The information of roads and traffic participants is mainly included, such as the position and orientation of lane lines, the road boundary, the position, orientation and speed of pedestrians, motor vehicles and bicycles, and the like.

The remote information receiving module can mainly receive and obtain remote information from various communication devices such as V2X, Wi-Fi, mobile communication, optical fiber, Ethernet and the like, and mainly comprises information which is sent by a nearby base station and is obtained through perception means. In addition, the remote information may further include information or emergency events received from the cloud server and describing a large range of physical quantities or obtained through statistics of a large amount of data, such as weather conditions, road congestion conditions, route repair and closing information, emergency notification, and the like.

After a specific message is produced, a specific message producer can determine the category of the specific message according to information in various aspects such as content, action, scene and the like of the message, and specifically can include two categories of emergency messages and non-emergency messages. From the view of message content, the emergency message mainly includes:

a) sudden changes in the position, orientation and speed of traffic participants such as pedestrians, motor vehicles, bicycles, such as sudden braking, lane changes, sudden falls by pedestrians or free-standing vehicles, traffic accidents, etc.;

b) the amount of change in key traffic lights, such as the traffic light turning red from green (yellow), the no-pass lights on, etc.;

c) sudden changes in road conditions, such as sudden dropping of a stationary obstacle on the road surface, a road damage that has just occurred, etc.;

d) notification of dangerous conditions, such as flood warnings, severe weather warnings, earthquake warnings, AMBER alerts, etc.;

the non-urgent messages mainly include:

a) the continuously changing amount of position, orientation and speed of traffic participants such as pedestrians, motor vehicles, bicycles;

b) the status and variation of non-critical traffic lights, such as traffic lights turning from red to green, no-pass lights going off and the like;

c) static information or continuous variation of roads, such as road congestion information, defects such as potholes and water accumulation on the road surface, road repair and closure information, and the like;

d) and broadcasting and predicting information on normal weather and traffic conditions, such as weather forecast, road congestion condition, average vehicle speed or average passing time of a certain road section, average waiting time of an intersection, and the like.

In a specific implementation, in order to facilitate a message producer to determine a category of a message, correspondence between various message contents and urgent and non-urgent may be stored in advance, for example, in one manner, a specific correspondence may be as shown in table 1:

TABLE 1

Message content	Categories
		Mutation amount of traffic participants	Emergency system
Variation of traffic signal lamp	Emergency system
		Continuously changing amount of traffic participants	Non-emergency
Static information or continuous variations of roads	Non-emergency
		……	……

The correspondence table may be stored in each message producer device that may produce a message, so that each time a message is produced, it may be compared with the correspondence table to determine whether the message belongs to an urgent message or a non-urgent message.

In addition, the embodiment of the application also improves the structural expression mode of the message, and can add the expression of the emergency or non-emergency type field of the message in the existing structural body. When a producer of the message produces a specific message, after determining the specific type of the emergency or non-emergency message, the message can be written into the message structure, so that a perception base station receiving the message can determine whether the message is the emergency message or the non-emergency message by identifying the target field value in the message structure, and adopt a targeted sending strategy to ensure that the emergency message is sent preemptively and ensure that the non-emergency message does not block the sending of other emergency messages.

Wherein, the definition of the message structure body can be as follows:

the field shown in bold is a field newly defined in the embodiment of the present application. Wherein, when the emergencyFlag is set to 1, the message is an emergency message; when emergencyFlag is set to 0, this message is a non-urgent message.

In addition, the content of the message generated by a specific message producer may vary, for example, some may carry information about traffic participants, some may carry information about static obstacles, some may be a notification message, and so on. Therefore, in order to facilitate the receiving base station to identify the information body of the message, a messageType field can be further set as an identifier of the type of the information body in the message, and the specific coding and meaning modes of the messageType field are shown in table 2:

TABLE 2

Wherein, the message type 1 indicates that the message carries the information of the transportation participant, the message type 2 indicates that the message carries the static obstacle information, and the message type 3 indicates that the message carries a notification. Wherein, the specific notice can adopt ASN.1 coding and is compatible with the existing industry standard. As technology develops, the contents of table 2 may expand, but the existing contents may remain unchanged.

Alternatively, in specific implementations, instead of sending a bit flag emergencyflag to indicate whether the entire message belongs to an urgent message, a priority _ idc signal may be sent, which may have a combined semantic meaning as shown above for the urgent flag and the messageType.

In summary, whether the message belongs to an urgent message or not can be identified by a specific urgent flag field or a priority field. After the local message, the allopatric message and the like are collected to the message classification module of the perception base station, the message classification module can identify whether a message belongs to an emergency message or a non-emergency message according to the information of a specific target field in the message. And then, different strategies are adopted for the emergency message and the non-emergency message respectively for sending processing.

The emergency message can be directly pushed into the first message queue, and the sending process of the message can be directly triggered to send the emergency message. And for non-urgent messages, the transmission time can be controlled by the TDMA control module. That is, it is necessary to wait for the time slot of the current cognitive base station to arrive before transmitting the non-urgent message. The TDMA control module can be connected with a time service module (such as a GNSS time service module) and used for receiving a time service signal of the time service module and actively reading a second message queue when the time slot arrives according to a time slot pre-allocated to the TDMA control module; and when the queue has the message, triggering a sending process, otherwise, waiting for the arrival of the next time slot. This arrangement ensures that all non-urgent messages are transmitted periodically in pre-allocated time slots. This allows urgent messages to be sent in a timely manner, while non-urgent messages are sent in specific time slots according to the TDMA protocol. Because the number of the non-urgent messages is larger, the situation that all or most of the messages are randomly sent does not occur, and the situation of packet loss caused by random sending of the urgent messages can be avoided to a certain extent.

The first message queue and the second message queue may have the following characteristics: (a) the data integrity of the message in the writing and reading processes is ensured, and the read-write conflict is avoided; (b) ensuring correct transmission order of messages when multiple messages are accumulated in the queue; (c) the real-time performance of reading and writing is ensured. However, the implementation of these two queues is different. The first message queue actively pushes the message at the tail of the queue (the earliest message entering the queue) to a sending process, and can monitor a feedback message; when a 'message sending completion' signal is received, if the queue still has messages which are not sent yet, the messages are continuously pushed to the sending process, and the process is repeated in such a circulating way until all the messages are sent completely. In contrast, the second message queue passively waits for the downstream module (TDMA control module) to read its own messages and may not have to listen to the downstream module's feedback. By this design, all urgent messages can be sent out in a triggering mode, and the minimum time delay is ensured.

Of course, in the process of sending the urgent message and the non-urgent message according to different strategies in the above manner, the following situations may occur:

in the first situation, a time slot currently obtained by a certain perception base station can send a non-emergency message, but an emergency message is generated or received at the same time;

in the second case, a certain sensing base station a currently generates or receives an urgent message and needs to transmit the urgent message immediately, but the current time is just in a time slot of another adjacent sensing base station B, that is, the sensing base station B may be transmitting a non-urgent message generated or received by the sensing base station B, so that the urgent message randomly transmitted in the sensing base station a and the non-urgent message transmitted by the sensing base station B in the obtained time slot may collide with each other. The collision may cause packet loss.

For this, the embodiment of the present application further provides a corresponding solution, and first, for the case one, an arbitration module 203 may be further provided in the cognitive base station, and configured to receive the urgent message pushed by the first message queue and the non-urgent message pushed by the TDMA control module; if the urgent message pushed by the first message queue is received in the time slot acquired by the perception base station, the urgent message is preferentially sent, and after the urgent message is sent, if the time slot is not finished, the non-urgent message pushed by the TDMA control module in the time slot is sent.

That is to say, in a specific implementation, after the message classification module 201 adds the urgent message to the first message queue, the urgent message in the first message queue may directly trigger a sending procedure to push the urgent message to the arbitration module 203; at this time, if the time slot of the current sensing base station has not arrived yet or the time slot has arrived but no non-urgent message is being sent, the urgent message may be directly sent.

Alternatively, the TDMA control module 202 may read non-urgent messages from the second message queue and push them to the arbitration module 203 when a time slot arrives. That is, the arbitration module 203 always receives the non-urgent message in the state of sensing that the base station acquires the timeslot, and at this time, if there is no urgent message to be sent, the non-urgent message may be directly sent.

However, for special cases, if the current cognitive base station obtains a time slot and the arbitration module 203 has already received a non-urgent message from the TDMA control module, if an urgent message pushed by the first message queue is also received in the time slot, the urgent message may be preferentially sent, after all the urgent messages are sent, whether the time slot is finished is judged, and if not, the non-urgent message pushed by the TDMA control module is sent. If the time slot has ended, non-urgent messages that have not yet been sent may be pushed back to the second message queue, waiting for the arrival of the next time slot.

In other words, the arbitration module may passively receive urgent messages sent from the first message queue, as well as passively receive non-urgent messages sent from the TDMA control module. If only the urgent message is received, the message is actively sent to the downstream module, and in addition, a message sending completion signal can be sent to the first message queue, and the message is continuously received. If only non-urgent messages are received, the message is actively transmitted and continues to be received. If the urgent message and the non-urgent message arrive at the same time, the urgent message is preferentially sent, a message sending completion signal is sent to the first message queue, whether the first message queue is still pushing the message to the first message queue is checked, and the steps are repeated in a circulating mode until all the urgent messages are sent completely; at this time, the arbitration module reads a clock (such as a GNSS time service module), and if the time is still in the current time slot, the non-urgent message is sent, otherwise, the non-urgent message is written back to the tail of the second message queue, and the arrival of the next time slot is waited.

In view of the second situation, in order to reduce the probability of collision between the emergency message randomly sent by the first sensing base station and the non-emergency message sent by the adjacent second base station when the time slot is obtained, the TDMA control module 202 may control the message sending time after the time slot is obtained, that is, after the time slot is obtained each time, some fragmented time slot resources may be reserved for the emergency message of the adjacent sensing base station instead of fully occupying the time slot with the emergency and/or non-emergency message, so that the probability of occurrence of the collision may be reduced. Specifically, after the associated cognitive base station obtains the time slot, the TDMA control module 202 may reserve time slot resources between the transmission occasions of the messages in the process of triggering transmission of the urgent message in the first message queue and/or the non-urgent message in the second message queue, so that the urgent message generated in the adjacent cognitive base station is transmitted by using the reserved time slot resources.

For example, as shown in fig. 3, suppose that base station a and base station B are adjacent to each other and time synchronization can be achieved between the two through GNSS timers, and suppose that t0 to t8 are time slots allocated to base station a and t8 to t9 are time slots allocated to base station B. In addition, suppose that the current time is just between t0 and t8, that is, the base station a obtains a time slot and can transmit some non-urgent message; however, if an urgent message is generated, the transmission can be performed at any time. In the embodiment of the present application, the base station a may reserve some time slot resources during the process of sending the message in the obtained time slot. For example, as shown in fig. 3, t0 to t1, t2 to t3, t4 to t5, t6 to t7, etc. may be time slot resources for transmitting messages in the base station a. And t 1-t 2, t 3-t 4, t 5-t 6, t 7-t 8 and the like can be reserved time slot resources. Thus, if an urgent message is generated in the neighboring base station B in a state in which the base station a acquires the slot, the urgent message has an opportunity to be transmitted during the reserved slot, thereby avoiding interference from the message transmitted in the base station a.

In a specific implementation, the proportion of the reserved timeslot resources in each timeslot may be determined according to a possible proportion of the emergency message in all messages. For example, assume that in general, the ratio of urgent messages to non-urgent messages is 1: 4, that is, the proportion of the emergency message in the total message is 1/5, a slot resource of 1/5 (in practical applications, may be slightly larger than 1/5, and may be determined according to practical situations, and the numbers herein are used for illustration only) may also be reserved in a specific slot for use when the emergency message is sent in a neighboring base station. Of course, in a specific implementation, the position where the reserved timeslot resource appears may also be random, so as to correspond to the characteristic that the emergency message appears randomly.

Therefore, through the participation of the arbitration module and the reservation of the time slot resource of the perception base station for specifically obtaining the time slot, the emergency message can be ensured to be sent in time to a great extent, the conflict with other messages being sent is reduced as much as possible, and the packet loss rate is reduced. If the urgent message generated in one base station can be generated when the time slot of the urgent message arrives immediately, on one hand, the urgent message can be ensured to be transmitted immediately, and on the other hand, the urgent message can be preferentially transmitted under the control of the arbitration module without being influenced by other messages. Therefore, in a specific implementation, in order to further control the packet loss rate, the generation timing of the message may be controlled so that the urgent message can be generated when the base station is about to acquire the time slot. Specifically, as described above, in the embodiment of the present application, a specific sensing base station includes information carried in a message that needs to be sent, a part of the information is from information sensed by a sensor system of the sensing base station itself, and another part of the information is from other signal sources. For the latter, the sensing base station can only receive specific information in a communication mode, but cannot control the generation timing of the information, and for the former, the specific information is generated in the sensing base station, so that the acquisition timing of the information can be controlled by controlling the triggering timing of the sensor, and further the generation timing of the message can be controlled. Specifically, the sensing base station may further include a sensing module, configured to sense a road traffic environment by triggering a sensor system, so as to obtain information in the road traffic environment and generate the message to be sent, where in a process of triggering the sensor system, a trigger time may be determined according to a time slot resource allocated to the sensing base station, so as to control an emergency message generated in the sensing base station to be generated when a time slot is coming or has come. Therefore, an emergency message can be sent immediately after being generated, and because the time slot arrives immediately or soon, the arbitration module can control the emergency message to be sent preferentially, and the influence of non-emergency messages sent inside the base station is avoided. For other adjacent base stations, because no time slot is obtained, the non-urgent message is not transmitted, and the urgent message can control the generation timing in the above manner, so that the message transmission in other base stations is also influenced. In a word, by the above mode, the urgent message and the non-urgent message in each sensing base station can be sent after obtaining the time slot as much as possible, so that the occurrence probability of collision is reduced, and the packet loss rate is reduced. Of course, for the emergency messages from other signal sources, since the base station receiving the emergency message cannot control the generation time, the scheme of immediately transmitting the emergency message after receiving the emergency message is still adopted, but since the generation of most of the emergency messages can be actually controlled, the probability of collision among a small number of emergency messages in the random transmission process is also relatively low.

Whether urgent messages or non-urgent messages exist, particularly after being pushed to a sending process, the urgent messages or the non-urgent messages can be finally written into a sending queue (for example, in the case of sending by using a V2X protocol, the sending queue can be a V2X sending queue), and the V2X sending queue is responsible for all messages sent by the passive receiving arbitration module and can be sent into a V2X channel at the fastest speed. Since the problem of prioritization has already been solved by the blanking module, it is sufficient that the V2X send queue sends all messages in sequence in the order in which they were received.

In summary, according to the embodiment of the present application, a relevant field is added in a message structure body to indicate whether a message belongs to an urgent message or a non-urgent message, so that, for a sensing base station that needs to send or forward the message, the urgent message and the non-urgent message can be sent according to different strategies. Wherein, the emergency message can be sent in time without waiting for the arrival of the time slot. For non-urgent messages, it is necessary to wait for a specific time slot to arrive before sending the message. Thereby ensuring that the urgent message can be sent out in a triggering mode and ensuring the minimum time delay. Meanwhile, non-urgent messages can be periodically sent out in pre-allocated time slots, and the packet loss rate is reduced on the whole.

In addition, in a preferred implementation, an arbitration module may be provided to which urgent messages may be sent once they are generated or received, and non-urgent messages may also be sent by the TDMA control module to the arbitration module after a time slot is specifically obtained. Therefore, if the emergency message and the non-emergency message in the same sensing base station arrive at the same time, the emergency message can be preferentially sent, and after the emergency message is sent, if the time slot is not finished, the non-emergency message is sent. Therefore, the priority sending of the emergency message is further realized, the time slot resources used by the emergency message and the non-emergency message are not conflicted, and the occurrence probability of packet loss is reduced.

Furthermore, in a preferred implementation manner, after each sensing base station obtains a time slot, specifically, when a non-urgent message is sent, some time slot resources may be reserved instead of occupying all time slots, so that the sensing base stations are used for the urgent message generated by the adjacent sensing base stations at any time, thereby reducing the mutual interference between the adjacent sensing base stations and further reducing the packet loss rate.

Example two

The second embodiment corresponds to the first embodiment, and provides a method for controlling message transmission in a cognitive base station, which may specifically include:

s401: obtaining at least one message to be sent, and determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message;

s402: adding a first type of message into a first message queue and triggering the sending of the first type of message;

s403: adding the second type of message to a second message queue;

s404: and acquiring a time service signal and time slot resource information distributed for the associated perception base station, and when a time slot arrives, reading a second type of message from the second message queue and triggering the sending of the second type of message.

In specific implementation, if the first type of message is generated in a state that the cognitive base station obtains a time slot, the first type of message can be preferentially sent; and after the first type message is sent, if the time slot is not finished, the second type message is sent. And if the time slot is finished, writing the second type of messages which are not sent back to the second message queue, and waiting for the arrival of the next time slot.

In addition, after the associated sensing base station obtains the time slot, in the process of sending and triggering the message in the second message queue, the time slot resource can be reserved between the sending opportunities of the message, so that the first-class message generated in the adjacent sensing base station can be sent by using the reserved time slot resource.

EXAMPLE III

The third embodiment provides a message generating method in a road traffic environment from the perspective of a message producer, and referring to fig. 5, the method may specifically include:

s501: the perception base station obtains information in a road traffic environment;

s502: determining the urgency of the information according to the information type, the action and/or the scene information of the information;

s503: and writing the information of the degree of urgency into a corresponding field in a preset message structure body to generate a message so as to determine a sending strategy of the message according to the degree of urgency.

In specific implementation, the sensor system can be triggered to sense the road traffic environment, so that information in the road traffic environment can be obtained.

At this time, in the process of triggering the sensor system, a triggering time can be further determined according to the time slot resource allocated to the associated sensing base station, so as to control the emergency message generated in the sensing base station to be generated when the time slot is about to come.

In addition, the information in the road traffic environment can be obtained by receiving information sent by other signal sources.

Wherein the other signal sources comprise other adjacent perception base stations, traffic participants, servers or other intelligent traffic equipment.

Specifically, when determining the urgency level of the information, the urgency level of the information may be determined and classified according to the information type, the role, and/or the scene of the information.

Specifically, if the information is that the position, the orientation and the speed of the traffic participant suddenly change, or a key traffic light changes, or the road state suddenly changes, or a dangerous condition occurs, the information is determined as the first type of information.

And if the information is that the position, the orientation and the speed of the traffic participant change suddenly and continuously, or the state of a non-key traffic light changes, or static information or continuous variable quantity of a road, or broadcasting and predicting information of normal weather and traffic conditions, determining the information as second type information.

Example four

The fourth embodiment further provides a message structure, wherein,

the message is used for being sent through a perception base station in the intelligent traffic system;

Corresponding to the second embodiment, an embodiment of the present application further provides a message sending control device in the cognitive base station, and referring to fig. 6, the message sending control device may include:

a message obtaining unit 601, configured to obtain at least one message to be sent, and determine that the message belongs to a first type of message or a second type of message according to a target field included in the message;

a first sending triggering unit 602, configured to add a first type of message to a first message queue, and trigger sending of the first type of message;

a queue adding unit 603, configured to add the second type of message to a second message queue;

and a second sending triggering unit 604, configured to obtain a time service signal and time slot resource information allocated to the associated cognitive base station, and when a time slot arrives, trigger sending of a second type of message after reading the second type of message from the second message queue.

In a specific implementation, the apparatus may further include:

an arbitration unit, configured to send a first type of message preferentially if the first type of message is generated in a state where the cognitive base station obtains a time slot; and after the first type message is sent, if the time slot is not finished, the second type message is sent.

Additionally, the arbitration unit may be further operable to:

and if the time slot is finished, writing the second type of messages which are not sent back to the second message queue, and waiting for the arrival of the next time slot.

In addition, the first sending trigger unit may specifically be configured to:

if the first type of message is generated under the state that the perception base station does not obtain the time slot, the first type of message is directly sent, wherein the time for sending the first type of message is in the time slot obtained by other adjacent perception base stations, and the other perception base stations obtaining the time slot reserve time slot resources for sending the first type of message.

Furthermore, the apparatus may further include:

and the time slot reservation unit is used for reserving time slot resources between the sending opportunities of the messages in the process of sending and triggering the second type of messages in the second message queue after the associated sensing base station obtains the time slot, so that the first type of messages generated in the adjacent sensing base station can be sent by utilizing the reserved time slot resources.

Corresponding to the three phases of the embodiment, the embodiment of the present application further provides a message generating apparatus in a road traffic environment, referring to fig. 7, the apparatus may be applied in a sensing base station, and includes:

an information obtaining unit 701 for obtaining information in a road traffic environment;

an urgency level determination unit 702, configured to determine an urgency level of the information according to an information type, an action, and/or scene information of the information;

a message generating unit 703, configured to write the information of the degree of urgency into a corresponding field in a preset message structure, and generate a message, so as to determine a sending policy of the message according to the degree of urgency.

Specifically, the information obtaining unit may be specifically configured to:

the sensor system is triggered to sense the road traffic environment, and information in the road traffic environment is obtained.

The information obtaining unit may be specifically configured to:

in the process of triggering the sensor system, a triggering occasion is determined according to the time slot resources allocated to the associated perception base station, so as to control the first type of messages generated in the perception base station to be generated when the time slot is about to come.

Alternatively, the information obtaining unit may specifically be configured to:

and obtaining the information in the road traffic environment by receiving the information sent by other information sources.

Wherein the other information sources comprise other adjacent perception base stations, traffic participants, servers or other intelligent traffic devices.

The urgency level determination unit may specifically be configured to:

and determining the urgency degree of the information and classifying the information according to the information type, the action and/or the scene of the information.

Specifically, the urgency level determination unit may be configured to:

and if the information is that the position, the direction and the speed of the traffic participant change suddenly, or a key traffic light changes, or the road state changes suddenly, or a dangerous condition occurs, determining the information as the first type of information.

Or, specifically, the urgency level determination unit may be configured to:

From the above description of the embodiments, it is clear to those skilled in the art that the present application can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present application may be essentially or partially implemented in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments of the present application.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement without inventive effort.

The perception base station in the road traffic environment and the message sending control method and device thereof provided by the application are introduced in detail, a specific example is applied in the description to explain the principle and the implementation mode of the application, and the description of the embodiment is only used for helping to understand the method and the core idea of the application; meanwhile, for a person skilled in the art, according to the idea of the present application, the specific embodiments and the application range may be changed. In view of the above, the description should not be taken as limiting the application.

Claims

1. A cognitive base station in a road traffic environment, comprising:

the time division multiplexing TDMA control module is used for acquiring a time service signal and time slot resource information distributed for the associated perception base station, and when the time slot arrives, the time division multiplexing TDMA control module reads a second type of message from the second message queue and triggers the sending of the second type of message; and reserving time slot resources between the sending opportunities of the second type of messages in the process of sending and triggering the second type of messages in the second message queue so as to send the first type of messages generated in the adjacent sensing base station by utilizing the reserved time slot resources.

2. The cognitive base station of claim 1,

the distance between adjacent perception base stations is smaller than the communication distance of the perception base stations;

the perception base stations transmit messages in a broadcasting mode, and the messages broadcasted by the first perception base station can be received by at least one second perception base station adjacent to the first perception base station;

wherein time division multiplexing is performed between adjacent cognitive base stations.

3. The cognitive base station of claim 1, further comprising:

the sensing module is used for sensing the road traffic environment through the trigger sensor system so as to obtain information in the road traffic environment and generate a message to be sent, wherein in the process of triggering the sensor system, a trigger time is determined according to the time slot resource allocated to the sensing base station so as to control the first type of message generated in the sensing base station to be generated when the time slot is about to come or is already coming.

4. The cognitive base station of claim 3, further comprising:

the arbitration module is used for receiving the first type of messages pushed by the first message queue and the second type of messages pushed by the TDMA control module after obtaining the time slot; if the first type of message pushed by the first message queue is received under the state that the perception base station obtains the time slot and receives the second type of message pushed by the TDMA control module, the first type of message is preferentially sent, and after the first type of message is sent, if the time slot is not finished, the second type of message pushed by the TDMA control module in the time slot is sent again.

5. The cognitive base station of claim 4,

the message classification module is specifically configured to, after adding a first type of message to a first message queue, push the first type of message in the first message queue to the arbitration module;

the TDMA control module is specifically used for reading a second type of message from the second message queue and pushing the second type of message to the arbitration module when a time slot arrives;

the arbitration module is specifically configured to, in a state where the sensing base station obtains a time slot and receives the second type of message from the TDMA control module, determine whether the first type of message pushed by the first message queue is received, if so, preferentially send the first type of message, after all the first type of messages are sent, determine whether the time slot is finished, and if not, send the second type of message pushed by the TDMA control module.

6. The cognitive base station of claim 4 or 5,

and the arbitration module is also used for writing back the second type of messages which are not sent to the second message queue if the time slot is finished and waiting for the arrival of the next time slot.

7. The cognitive base station of claim 1, further comprising:

and the communication module is used for receiving the messages to be sent from other information sources, and the received messages to be sent comprise first-type messages or second-type messages.

8. The cognitive base station of claim 1,

the proportion of the reserved time slot resources in each time slot is determined according to the possible proportion of the first type of messages in all the messages.

9. A method for controlling message transmission in a cognitive base station, comprising:

obtaining at least one message to be sent, and determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message; determining the type of the message by a message producer according to the message content of the message and a pre-stored corresponding relation, and writing the determined type information into the target field in the structural body of the message;

adding the second type of message to a second message queue;

acquiring a time service signal and time slot resource information distributed for an associated sensing base station, and when a time slot arrives, reading a second type of message from the second message queue and triggering the sending of the second type of message; after the associated sensing base station obtains the time slot, in the process of sending and triggering the second type of messages in the second message queue, time slot resources are reserved between the sending opportunities of the second type of messages, so that the first type of messages generated in the adjacent sensing base station can be sent by utilizing the reserved time slot resources.

10. The method of claim 9, further comprising:

if the first type of message is generated in the state that the perception base station obtains the time slot, the first type of message is preferentially sent; and after the first type message is sent, if the time slot is not finished, the second type message is sent.

11. The method of claim 10, further comprising:

12. The method of claim 9, further comprising:

13. A method of message generation in a road traffic environment, comprising:

the perception base station obtains information in a road traffic environment;

determining the urgency degree of the information according to the information type, the action and/or the scene information of the information and the corresponding relation which is stored in advance;

writing the information of the emergency degree into a corresponding field in a preset message structure body to generate a message so as to determine a sending strategy of the message according to the emergency degree;

when the message is required to be sent, determining at least one message to be sent, determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message, adding the first type of message into a first message queue, triggering the sending of the first type of message, and adding the second type of message into a second message queue;

acquiring a time service signal and time slot resource information distributed for an associated sensing base station, and when a time slot arrives, reading a second type of message from the second message queue and triggering the sending of the second type of message; and reserving time slot resources between the sending opportunities of the second type of messages in the process of sending and triggering the second type of messages in the second message queue so as to send the first type of messages generated in the adjacent sensing base station by utilizing the reserved time slot resources.

14. The method of claim 13,

the obtaining information in a road traffic environment includes:

15. The method of claim 14,

the sensing of the road traffic environment by the trigger sensor system to obtain information in the road traffic environment comprises:

16. The method of claim 13,

the obtaining information in a road traffic environment includes:

17. The method of claim 16,

the other information sources comprise other adjacent perception base stations, traffic participants, servers or other intelligent traffic equipment.

18. The method of claim 13,

the determining the urgency of the information includes:

19. The method of claim 18,

the determining the urgency level of the information and classifying the urgency level of the information includes:

20. The method of claim 18,

21. A message structure, characterized in that,

the message structure body comprises a first type message or a second type message mark field, and is used for carrying out trigger type sending on the first type message according to the emergency degree of the message and sending on the second type message according to a time division multiplexing protocol; wherein the triggered sending is: and sending the first type of message after the first type of message is generated, wherein the sending according to a time division multiplexing protocol comprises the following steps: sending the time slot after the time slot for allocating the perception base station arrives; and reserving time slot resources between the sending opportunities of the second type of messages in the process of sending and triggering the second type of messages in the second message queue so as to send the first type of messages generated in the adjacent sensing base station by utilizing the reserved time slot resources.

22. A message transmission control apparatus in a cognitive base station, comprising:

the message obtaining unit is used for obtaining at least one message to be sent and determining whether the message belongs to a first type of message or a second type of message according to a target field included in the message; determining the type of the message by a message producer according to the message content of the message and a pre-stored corresponding relation, and writing the determined type information into the target field in the structural body of the message;

the second sending triggering unit is used for acquiring a time service signal and time slot resource information distributed for the associated sensing base station, and when a time slot arrives, the sending of a second type of message is triggered after the second type of message is read from the second message queue; and reserving time slot resources between the sending opportunities of the second type of messages in the process of sending and triggering the second type of messages in the second message queue so as to send the first type of messages generated in the adjacent sensing base station by utilizing the reserved time slot resources.

23. A message generating device in a road traffic environment is applied to a perception base station, and comprises:

the emergency degree determining unit is used for determining the emergency degree of the information according to the information type, the action and/or the scene information of the information and the corresponding relation which is stored in advance;

the message generating unit is used for writing the information of the emergency degree into a corresponding field in a preset message structure body to generate a message so as to determine a sending strategy of the message according to the emergency degree;

when message sending is needed, at least one message to be sent is determined, whether the message belongs to a first type of message or a second type of message is determined according to a target field included in the message, the first type of message is added into a first message queue, sending of the first type of message is triggered, and the second type of message is added into a second message queue;