Vehicle cooperative braking method, device, equipment and program product based on V2X

Abstract

The invention discloses a V2X-based vehicle cooperative braking method, device, equipment and program product, and the method comprises the steps: a current vehicle detects a front obstacle, calculates first collision time according to the obstacle information, and determines an expected deceleration according to the first collision time; when the first collision time is smaller than a preset first threshold value, a cooperative braking request is generated according to the first position of the front vehicle, the first vehicle speed and the expected deceleration, and the cooperative braking request is broadcasted through V2X; if the front vehicle receives the cooperative braking response of the rear vehicle, the front vehicle is controlled to brake according to the expected deceleration, if the front vehicle does not receive the cooperative braking response, the expected deceleration is adjusted to obtain the target deceleration, the front vehicle is controlled to brake according to the target deceleration, and acousto-optic early warning is conducted. The rear-end collision risk of the vehicle is reduced, so that the driving safety of the vehicle is improved, and the method can be applied to the technical field of vehicle control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, and in particular to a vehicle cooperative braking method and device based on V2X, a vehicle cooperative braking apparatus, and a program product. BACKGROUND

[0002] The existing AEB system (automatic emergency braking system) mainly relies on the sensors of the vehicle to perceive the front obstacles, and triggers emergency braking when detecting collision risk. However, this single-vehicle braking strategy has the following problems: 1) Information island: the front vehicle cannot predict the state of the rear vehicle, and emergency braking is prone to cause chain rear-end collisions; 2) Reaction delay: the rear driver or system needs additional reaction time, resulting in braking lag; 3) Low energy management efficiency: independent braking of each vehicle cannot optimize the overall kinetic energy distribution.

[0003] The above problems need to be solved. SUMMARY

[0004] The present application aims to at least partially solve one of the problems in the prior art.

[0005] To this end, one object of the present application is to provide a vehicle cooperative braking method based on V2X, which realizes cooperative braking of the front and rear vehicles through V2X communication, and dynamically adjusts the expected deceleration of the front vehicle when it does not receive the cooperative braking response of the rear vehicle, so that the rear driver has enough reaction time for manual braking, reducing the risk of vehicle rear-end collisions and improving the driving safety of the vehicle.

[0006] Another object of the present application is to provide a vehicle cooperative braking device based on V2X.

[0007] In order to achieve the above technical purpose, the technical solution adopted by the present application comprises: On the one hand, the present application provides a vehicle cooperative braking method based on V2X, comprising the following steps: The front vehicle detects a front obstacle, calculates a first collision time according to the obstacle information, and determines an expected deceleration according to the first collision time; When the first collision time is less than a preset first threshold, a cooperative braking request is generated according to the first position, first speed and expected deceleration of the front vehicle, and the cooperative braking request is broadcasted through V2X; If the front vehicle receives the cooperative braking response of the rear vehicle, the front vehicle is controlled to brake at the expected deceleration; if the front vehicle does not receive the cooperative braking response, a target deceleration is obtained by adjusting the expected deceleration, and the front vehicle is controlled to brake at the target deceleration and sound and light warning is performed.

[0008] Further, in an embodiment of the present application, the vehicle cooperative braking method further comprises the following steps: When the rear vehicle receives the cooperative braking request, a second collision time is calculated according to the second position, the second vehicle speed of the rear vehicle and the cooperative braking request, and a pre-braking deceleration is determined according to the second collision time; The rear vehicle is controlled to pre-brake at the pre-braking deceleration, and a cooperative braking response is generated according to the pre-braking deceleration, and then the cooperative braking response is returned to the front vehicle through V2X.

[0009] Further, in an embodiment of the present application, the obstacle information comprises obstacle position and obstacle speed, and the first collision time is calculated according to the obstacle information, and the expected deceleration is determined according to the first collision time, which specifically comprises: A first relative distance is determined according to the obstacle position and the first position of the front vehicle; A first relative speed is determined according to the obstacle speed and the first vehicle speed of the front vehicle; The first collision time is calculated according to the first relative distance and the first relative speed; A minimum deceleration is calculated according to the first relative distance, the first vehicle speed and a preset minimum safety distance; A corresponding first braking coefficient is determined according to the first collision time and a preset front vehicle braking coefficient mapping table; The expected deceleration is determined according to the minimum deceleration and the first braking coefficient; Wherein, the first braking coefficient is greater than 1.

[0010] Further, in an embodiment of the present application, the first collision time is determined by the following formula:

[0011] Wherein, The first collision time is represented by T1, The first relative distance is represented by D1, The first vehicle speed is represented by V1, The obstacle speed is represented by V0; The minimum deceleration is determined by the following formula:

[0012] wherein, represents a minimum deceleration, represents a minimum safety distance; The expected deceleration is determined by the following formula:

[0013] wherein, represents an expected deceleration, represents a first braking coefficient, represents a maximum deceleration corresponding to a current road surface adhesion coefficient.

[0014] Further, in an embodiment of the present application, the second collision time is calculated according to the second position of the rear vehicle, the second vehicle speed and the cooperative braking request, and the pre-braking deceleration is determined according to the second collision time, which specifically comprises: The cooperative braking request is parsed to obtain the first position, the first vehicle speed and the expected deceleration; A second relative distance is determined according to the first position and the second position; A second relative speed is determined according to the first vehicle speed and the second vehicle speed; The second collision time is calculated according to the second relative distance, the second relative speed and the expected deceleration; A corresponding second braking coefficient is determined according to the second collision time and a preset rear vehicle braking coefficient mapping table; The pre-braking deceleration is determined according to the expected deceleration and the second braking coefficient; Wherein, the second braking coefficient is less than 1.

[0015] Further, in an embodiment of the present application, the second collision time is determined by the following formula:

[0016] wherein, represents a second collision time, represents a second relative distance, represents a second relative speed, represents an expected deceleration; The pre-braking deceleration is determined by the following formula:

[0017] wherein, represents a pre-braking deceleration, represents a first braking coefficient, represents a maximum deceleration corresponding to a current road surface adhesion coefficient.

[0018] Further, in one embodiment of the present application, the adjustment on the expected deceleration to obtain a target deceleration specifically comprises: obtaining a second position and a second speed of the rear vehicle through a roadside device; determining a second relative distance according to the first position and the second position; determining a second relative speed according to the first speed and the second speed; calculating a second collision time according to the second relative distance, the second relative speed and the expected deceleration; determining a minimum braking time length of the rear vehicle according to the second speed, and determining a collision time safety interval according to the minimum braking time length and a preset driver reaction time interval; determining a target adjustment coefficient according to the second collision time and the collision time safety interval; determining the target deceleration according to the expected deceleration and the target adjustment coefficient.

[0019] Further, in one embodiment of the present application, the minimum braking time length is determined by the following formula:

[0020] wherein, represents the minimum braking time length, represents the second speed, represents a maximum deceleration corresponding to a current road surface adhesion coefficient; the collision time safety interval is determined by the following formula:

[0021]

[0022] wherein, and respectively represent a lower limit value and an upper limit value of the collision time safety interval, represents a lower limit value and an upper limit value of the driver reaction time interval; the target adjustment coefficient is determined by the following formula:

[0023] wherein, represents the target adjustment coefficient, represents the second collision time; the target deceleration is determined by the following formula:

[0024] wherein, represents the target deceleration, represents the expected deceleration, represents the minimum deceleration ensuring that the preceding vehicle does not collide with the front obstacle.

[0025] In another aspect, an embodiment of the present application provides a vehicle cooperative braking device based on V2X, comprising: a desired deceleration determination module configured to, when the preceding vehicle detects a front obstacle, calculate a first collision time according to the obstacle information, and determine a desired deceleration according to the first collision time; a cooperative braking request module configured to, when the first collision time is less than a preset first threshold, generate a cooperative braking request according to the first position, the first speed of the preceding vehicle and the desired deceleration, and broadcast the cooperative braking request through V2X; a braking control module configured to, if the preceding vehicle receives a cooperative braking response of a following vehicle, control the preceding vehicle to brake at the desired deceleration, and if the preceding vehicle does not receive the cooperative braking response, adjust the desired deceleration to obtain a target deceleration, control the preceding vehicle to brake at the target deceleration and perform sound and light pre-warning.

[0026] In another aspect, an embodiment of the present application provides an electronic device, comprising: at least one processor; at least one memory configured to store at least one program; when the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned vehicle cooperative braking method based on V2X.

[0027] In another aspect, an embodiment of the present application further provides a computer readable storage medium, wherein a computer program executable by a processor is stored, and the computer program implements the above-mentioned vehicle cooperative braking method based on V2X when executed by the processor.

[0028] In another aspect, an embodiment of the present application further provides a computer program product, comprising a computer program, and the computer program implements the above-mentioned vehicle cooperative braking method based on V2X when executed by a processor.

[0029] The advantages and beneficial effects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present application: The front vehicle of the embodiment of the application detects a front obstacle, calculates a first collision time according to the obstacle information, and determines an expected deceleration according to the first collision time, generates a cooperative braking request according to the first position, the first speed and the expected deceleration of the front vehicle when the first collision time is less than a preset first threshold, and broadcasts the cooperative braking request through V2X, controls the front vehicle to brake at the expected deceleration if the front vehicle receives the cooperative braking response of the rear vehicle, adjusts the expected deceleration to obtain a target deceleration if the front vehicle does not receive the cooperative braking response, and controls the front vehicle to brake at the target deceleration and performs sound and light pre-warning. The embodiment of the application realizes cooperative braking of the front vehicle and the rear vehicle through V2X communication, dynamically adjusts the expected deceleration of the front vehicle when the front vehicle does not receive the cooperative braking response of the rear vehicle, so that the rear vehicle driver can have enough reaction time for manual braking, reduces the risk of rear-end collision of the vehicle, and improves the driving safety of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following introduces the drawings needed to be used in the embodiments of the application. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments in the technical solutions of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0031] Figure 1 A step flow chart of a vehicle cooperative braking method based on V2X provided by the embodiment of the application is provided. Figure 2 A principle schematic diagram of a vehicle cooperative braking method based on V2X provided by the embodiment of the application is provided. Figure 3 A cooperative braking timing schematic diagram of a vehicle cooperative braking method based on V2X provided by the embodiment of the application is provided. Figure 4 A mixed traffic scene schematic diagram of a vehicle cooperative braking method based on V2X provided by the embodiment of the application is provided. Figure 5 A structure block diagram of a vehicle cooperative braking device based on V2X provided by the embodiment of the application is provided. Figure 6 A structure block diagram of an electronic device provided by the embodiment of the application is provided. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with embodiments of the present application. They are only examples of apparatuses and methods consistent with some aspects of embodiments of the present application as detailed in the appended claims.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the present application only and is not intended to limit the present application.

[0034] The V2X-based vehicle cooperative braking method provided by the embodiments of the present application can be applied to a terminal, can be applied to a server, and can also be software running in the terminal or the server. In some embodiments, the terminal can be a smart phone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, a vehicle-mounted terminal, and the like, but is not limited thereto. The server end can be configured as a stand-alone physical server, can be configured as a server cluster or a distributed system formed by multiple physical servers, can be configured as a cloud server providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and basic cloud computing services such as big data and artificial intelligence platforms, and the server can also be a node server in a blockchain network. The software can be an application that implements the V2X-based vehicle cooperative braking method, and the like, but is not limited to the above forms.

[0035] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, multi-processor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present application can also be practiced in a distributed computing environment in which tasks are performed by remote processing devices connected by a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0036] It should be noted that in various specific embodiments of the present application, when relevant processing needs to be performed on data related to the identity or characteristics of the user, such as user information, user behavior data, user history data, and user location information, the user's permission or consent is obtained first, and the collection, use, and processing of such data comply with relevant laws, regulations, and standards. In addition, when the embodiments of the present application need to obtain sensitive personal information of the user, the user's separate permission or separate consent is obtained through a pop-up window or by jumping to a confirmation page, and after obtaining the separate permission or separate consent of the user, the necessary user-related data for enabling the embodiments of the present application to function normally is obtained.

[0037] The existing AEB system only relies on the front-end sensor of the vehicle to detect obstacles, and outputs the maximum deceleration once the collision risk is determined. This single-point braking strategy can reduce the speed of the front vehicle in the 120km / h high-speed scenario, but cannot perceive the state of the rear vehicle, and the rear vehicle is forced to rear-end at a high relative speed when emergency braking, forming a negative externality of "safe front vehicle, high-risk rear vehicle", which makes the high-speed chain collision injury and death rate high.

[0038] Based on the above background, the technical problems to be solved by the present application include but are not limited to: 1) how does the front vehicle know "whether there is a vehicle behind" and "whether the rear vehicle has cooperated with deceleration" within milliseconds; 2) on the premise that the front collision can still be avoided or a slight front collision can be accepted, how much deceleration should the front vehicle output to minimize the total collision energy.

[0039] The popularity of V2X technology (including V2V vehicle-to-vehicle communication and V2I roadside communication) provides a new way to solve the above problems, but existing V2X applications are mostly limited to information warning and have not been deeply integrated into the braking execution level.

[0040] With reference to Figure 1 The embodiments of the present application provide a vehicle cooperative braking method based on V2X, which specifically comprises the following steps: S101, the front vehicle detects a front obstacle, calculates a first collision time according to the obstacle information, and determines an expected deceleration according to the first collision time; S102, when the first collision time is less than a preset first threshold, a cooperative braking request is generated according to the first position, the first speed of the front vehicle, and the expected deceleration, and the cooperative braking request is broadcasted through V2X; S103, if the front vehicle receives a cooperative braking response of the rear vehicle, the front vehicle is controlled to brake at the expected deceleration, if the front vehicle does not receive the cooperative braking response, the expected deceleration is adjusted to obtain a target deceleration, and the front vehicle is controlled to brake at the target deceleration and sound and light warning is performed.

[0041] The specific implementation process of the embodiment of the present application is described below. Since the vehicle cooperative braking method of the embodiment of the present application takes the preceding vehicle as the main body, the preceding vehicle will also be referred to as the subject vehicle in the following description, which does not affect the implementation of the embodiment of the present application.

[0042] As shown in Figure 2 The principle diagram of a vehicle cooperative braking method based on V2X provided by the embodiment of the present application is shown, wherein the subject vehicle and the following vehicle are both equipped with sensors (cameras / millimeter wave radars), V2X communication modules and cooperative braking controllers. The V2X communication module and the forward sensor of the subject vehicle are coupled with the cooperative braking controller, the forward sensor is used to obtain the front obstacle information, the cooperative braking controller of the subject vehicle is used to calculate the first collision time of the subject vehicle and the front obstacle and the expected deceleration of the subject vehicle, and the V2X communication module of the subject vehicle is used to communicate with the following vehicle, and the V2X communication supports PC5 or LTE-V protocol. The V2X communication module and the rear sensor of the following vehicle are coupled with the cooperative braking controller, the V2X communication module of the following vehicle is used to communicate with the subject vehicle, the cooperative braking controller of the following vehicle is used to calculate the second collision time of the following vehicle and the subject vehicle and the pre-braking deceleration of the following vehicle, and the rear sensor is used to verify the subject vehicle information.

[0043] Further as an optional implementation, the vehicle cooperative braking method further comprises the following steps: S201, when the following vehicle receives the cooperative braking request, the second collision time is calculated according to the second position, the second vehicle speed of the following vehicle and the cooperative braking request, and the pre-braking deceleration is determined according to the second collision time; S202, the following vehicle is controlled to pre-brake according to the pre-braking deceleration, and a cooperative braking response is generated according to the pre-braking deceleration, and then the cooperative braking response is returned to the preceding vehicle through V2X.

[0044] As shown in Figure 3The diagram illustrates the cooperative braking timing of a V2X-based vehicle cooperative braking method according to an embodiment of the present invention. Specifically: the vehicle detects an obstacle ahead using a forward-facing sensor and calculates a first collision time; when the first collision time is less than a first threshold (e.g., 2.5s), the vehicle broadcasts a "cooperative braking request" message via V2X, including its vehicle ID, first position, first speed, expected deceleration (e.g., 0.6g), and expected braking trajectory (e.g., 0.6g deceleration lasting 3 seconds); after receiving the cooperative braking request via V2X, the following vehicle first verifies the vehicle information using a backward-facing sensor (to prevent forgery), and then calculates the second collision time between the following vehicle and the vehicle. If the second collision time is less than... If the safety threshold is reached, pre-braking is triggered, establishing 0.3g of braking pressure in advance (200ms faster than the driver's reaction), simultaneously illuminating the high-mounted brake light, and returning the coordinated braking response to the vehicle. The vehicle and the following vehicle exchange braking states in real time via V2X, and dynamically adjust the expected deceleration of the vehicle based on the coordinated braking response of the following vehicle. If the following vehicle has responded, the vehicle can maintain the expected deceleration; if the following vehicle has not responded, the vehicle adjusts the expected deceleration to obtain the target deceleration (e.g., reducing it to 0.4g) and triggers an audible and visual warning. Throughout the process, braking states are exchanged in real time via V2X until both vehicles have completed deceleration or come to a stop. After braking is completed, both vehicles send a braking completion message via V2X to release the braking pressure.

[0045] like Figure 4 The diagram illustrates a hybrid traffic scenario using a V2X-based vehicle cooperative braking method according to an embodiment of the present invention. Specifically: 1) The cooperative braking controller of the vehicle (120 km / h) calculates the first collision time with the obstacle ahead as 2.4 s and the expected deceleration of the vehicle as 0.6 g. Then, the vehicle broadcasts a cooperative braking request via the V2X communication module. After receiving the cooperative braking request, the cooperative braking controller of the following vehicle A (140 km / h) calculates the second collision time with the preceding vehicle as 1.3 s and the pre-braking deceleration as 0.3 g. Then, it returns a cooperative braking response to the vehicle, which then maintains its braking speed. 1) The expected deceleration was 0.6g, and the final relative speed of the rear-end collision decreased from 58km / h to 28km / h; 2) The cooperative braking controller of this vehicle (120km / h) calculated that the first collision time with the obstacle in front was 2.4s and the expected deceleration of this vehicle was 0.6g. Then, this vehicle broadcast a cooperative braking request through the V2X communication module. If the V2X module of the following vehicle B (140km / h) malfunctions and this vehicle detects that the following vehicle B has no response, it will automatically adjust the expected deceleration to 0.4g and trigger an audible and visual warning so that the driver of the following vehicle B can manually or automatically adjust the deceleration. Finally, the relative speed of the rear-end collision decreased from 58km / h to 43km / h.

[0046] It can be recognized that the embodiment of the present application realizes cooperative braking of the front vehicle and the rear vehicle through V2X communication, and dynamically adjusts the expected deceleration of the front vehicle when the front vehicle does not receive the cooperative braking response of the rear vehicle, so that the rear vehicle driver can have enough reaction time for manual braking, reduces the risk of rear-end collision of the vehicle, and improves the driving safety of the vehicle.

[0047] Further as an optional implementation, the obstacle information includes an obstacle position and an obstacle speed, a first collision time is calculated according to the obstacle information, and the expected deceleration is determined according to the first collision time, which specifically includes: S1011, determining a first relative distance according to the obstacle position and a first position of the front vehicle; S1012, determining a first relative speed according to the obstacle speed and a first vehicle speed of the front vehicle; S1013, calculating a first collision time according to the first relative distance and the first relative speed; S1014, calculating a minimum deceleration according to the first relative distance, the first vehicle speed and a preset minimum safety distance; S1015, determining a corresponding first braking coefficient according to the first collision time and a preset front vehicle braking coefficient mapping table; S1016, determining the expected deceleration according to the minimum deceleration and the first braking coefficient; Wherein, the first braking coefficient is greater than 1.

[0048] Further as an optional implementation, the first collision time is determined by the following formula:

[0049] Wherein, represents the first collision time, represents the first relative distance, represents the first vehicle speed, represents the obstacle speed; The minimum deceleration is determined by the following formula:

[0050] Wherein, represents the minimum deceleration, represents the minimum safety distance; The expected deceleration is determined by the following formula:

[0051] Wherein, represents the expected deceleration, represents the first braking coefficient, represents the maximum deceleration corresponding to the current road adhesion coefficient.

[0052] Specifically, based on the location of the obstacle and the first position of the car in front Determine the first relative distance According to the speed of the obstacle and the first speed of the car in front Determine the first relative velocity According to the first relative distance and first relative velocity Calculate the time of the first collision .

[0053] Obtain the preset minimum safe distance (Usually taken as 2-5m), the minimum safe distance is the distance that must be maintained between the vehicle in front and the obstacle after the vehicle in front has completed braking. Therefore, the actual maximum braking distance of the vehicle in front is According to the first vehicle speed and the maximum braking distance The minimum deceleration of the vehicle in front is calculated. .

[0054] Based on the first collision time The corresponding first braking coefficient is obtained by querying the pre-built table of front vehicle braking coefficients. The braking coefficient table for the preceding vehicle was obtained through experimental calibration, for example, at the time of the first collision. The first braking coefficient corresponding to 2.4s It is 1.2.

[0055] Determine the desired deceleration based on the minimum deceleration and the first braking coefficient. That is, when The maximum deceleration is greater than the current road surface adhesion coefficient. ,Will As the desired deceleration.

[0056] As a further optional implementation, the second collision time is calculated based on the second position of the following vehicle, the second vehicle speed, and the cooperative braking request, and the pre-braking deceleration is determined based on the second collision time, specifically including: S2011. The coordinated braking request is parsed to obtain the first position, the first vehicle speed, and the desired deceleration. S2012. Determine the second relative distance based on the first and second positions; S2013. Determine the second relative speed based on the first vehicle speed and the second vehicle speed; S2014. Calculate the second collision time based on the second relative distance, the second relative velocity, and the desired deceleration. S2015, determining a second braking coefficient corresponding to the second collision time according to a preset rear vehicle braking coefficient mapping table; S2016, determining a pre-braking deceleration according to the expected deceleration and the second braking coefficient; wherein the second braking coefficient is less than 1.

[0057] Further as an optional implementation, the second collision time is determined by the following formula:

[0058] wherein, represents the second collision time, represents the second relative distance, represents the second relative speed, represents the expected deceleration; The pre-braking deceleration is determined by the following formula:

[0059] wherein, represents the pre-braking deceleration, represents the first braking coefficient, represents the maximum deceleration corresponding to the current road adhesion coefficient.

[0060] Specifically, the cooperative braking request is parsed to obtain the first position , the first vehicle speed , and the expected deceleration , the second relative distance is determined according to the first position and the second position , the second relative speed is determined according to the first vehicle speed and the second vehicle speed , the second collision time is calculated according to the second relative distance , the second relative speed , and the expected deceleration , considering the braking behavior of the front vehicle based on the expected deceleration.

[0061] The second braking coefficient corresponding to the second collision time is obtained by querying a pre-constructed rear vehicle braking coefficient table, which is obtained by experiment calibration, for example, when the second collision time is 1.3s, the corresponding second braking coefficient is 0.8.

[0062] The pre-braking deceleration that is, when greater than the maximum deceleration corresponding to the current road adhesion coefficient , the target deceleration is determined as the expected deceleration. as the pre-braking deceleration.

[0063] Further, as an optional embodiment, the expected deceleration is adjusted to obtain the target deceleration, which specifically includes: S1031, acquiring the second position and the second speed of the rear vehicle through the roadside device; S1032, determining the second relative distance according to the first position and the second position; S1033, determining the second relative speed according to the first speed and the second speed; S1034, calculating the second collision time according to the second relative distance, the second relative speed, and the expected deceleration; S1035, determining the minimum braking time of the rear vehicle according to the second speed, and determining the collision time safety interval according to the minimum braking time and the preset driver reaction time interval; S1036, determining the target adjustment coefficient according to the second collision time and the collision time safety interval; S1037, determining the target deceleration according to the expected deceleration and the target adjustment coefficient.

[0064] Specifically, when the front vehicle does not receive the cooperative braking response of the rear vehicle, the front vehicle still needs to calculate the second collision time of the rear vehicle and the front vehicle, and adjust the expected deceleration based on the second collision time.

[0065] In the embodiment of the application, the roadside device is introduced to acquire the second position and the second speed of the rear vehicle through a camera, a radar and other sensors, and then transmit them to the front vehicle, and the second collision time is calculated by the cooperative braking controller of the front vehicle. The specific calculation process is consistent with the process of calculating the second collision time by the rear vehicle, and will not be repeated here.

[0066] When determining the target adjustment coefficient , , the second collision time should be smaller, and the coefficient should be larger (that is, the front vehicle deceleration reduction is smaller, to avoid rear-end collision due to excessive deceleration when the distance between the two vehicles is too close), and the second collision time should be larger, and the coefficient should be smaller (the front vehicle can reduce the deceleration by a larger margin to give the rear vehicle driver sufficient reaction time).

[0067] Further, as an optional embodiment, the minimum braking time is determined by the following formula:

[0068] wherein, denotes a minimum braking duration, denotes a second vehicle speed, denotes a maximum deceleration corresponding to a current road adhesion coefficient; The collision time safety interval is determined by:

[0069]

[0070] wherein, and respectively denote a lower limit value and an upper limit value of the collision time safety interval, denote a lower limit value and an upper limit value of the driver reaction time interval; The target adjustment coefficient is determined by:

[0071] wherein, denotes the target adjustment coefficient, denotes a second collision time; The target deceleration is determined by:

[0072] wherein, denotes the target deceleration, denotes an expected deceleration, denotes a minimum deceleration ensuring that the preceding vehicle does not collide with the preceding obstacle.

[0073] Specifically, according to the second vehicle speed and the maximum deceleration corresponding to the current road adhesion coefficient the minimum braking duration of the following vehicle is determined , while the preset driver reaction time interval (such as 1.2~2.0s) is obtained, according to the minimum braking duration and the driver reaction time interval the collision time safety interval is determined.

[0074] According to the second collision time and the collision time safety interval the target adjustment coefficient is determined, when the target adjustment coefficient takes 0.8, when the target adjustment coefficient takes 0.2, when the target adjustment coefficient .

[0075] According to the expected deceleration and target adjustment coefficient determining target deceleration , that is, is less than the minimum deceleration ensuring that the preceding vehicle does not collide with the front obstacle , the is taken as the adjusted target deceleration.

[0076] The method steps of the embodiments of the present application are described above. It can be recognized that the embodiments of the present application realize cooperative braking of the preceding vehicle and the following vehicle through V2X communication, and dynamically adjust the expected deceleration of the preceding vehicle when the preceding vehicle does not receive the cooperative braking response of the following vehicle, so that the following vehicle driver can have enough reaction time for manual braking, reducing the risk of rear-end collision of the vehicle, thereby improving the driving safety of the vehicle.

[0077] Compared with the prior art, the embodiments of the present application have the following advantages: 1) Cross-vehicle braking pressure pre-establishment: the following vehicle can pre-establish braking pressure according to the cooperative braking request of the preceding vehicle without waiting for the driver's reaction, reducing the risk of rear-end collision.

[0078] 2) Dynamic deceleration game: the preceding vehicle can adjust its braking intensity in real time according to the response state of the following vehicle, so as to appropriately reduce its deceleration when the following vehicle does not respond to make the following vehicle driver have enough reaction time for manual braking.

[0079] 3) Multi-modal verification: the following vehicle can verify whether there is a cooperative braking demand in combination with V2X messages and sensor data to prevent communication fraud.

[0080] With reference to Figure 5 , the embodiments of the present application provide a vehicle cooperative braking device based on V2X, comprising: an expected deceleration determination module configured to detect a front obstacle by the preceding vehicle, calculate a first collision time according to the obstacle information, and determine an expected deceleration according to the first collision time; a cooperative braking request module configured to generate a cooperative braking request according to the first position, the first speed and the expected deceleration of the preceding vehicle when the first collision time is less than a preset first threshold, and broadcast the cooperative braking request through V2X; a braking control module configured to control the preceding vehicle to brake at the expected deceleration if the preceding vehicle receives the cooperative braking response of the following vehicle, adjust the expected deceleration to obtain a target deceleration if the preceding vehicle does not receive the cooperative braking response, control the preceding vehicle to brake at the target deceleration and perform sound and light pre-warning.

[0081] It can be understood that the contents in the above method embodiments are all applicable to the device embodiments, the device embodiments specifically implement the functions same as those of the above method embodiments, and achieve the same beneficial effects as those of the above method embodiments.

[0082] With reference to Figure 6 The embodiment of the present application provides an electronic device, which comprises: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned V2X-based vehicle cooperative braking method.

[0083] It can be understood that the contents in the above method embodiments are all applicable to the device embodiments, the device embodiments specifically implement the functions same as those of the above method embodiments, and achieve the same beneficial effects as those of the above method embodiments.

[0084] The embodiment of the present application further provides a computer readable storage medium, wherein a computer program executable by a processor is stored, and the computer program implements the above-mentioned V2X-based vehicle cooperative braking method when executed by the processor.

[0085] The computer readable storage medium of the embodiment of the present application can execute the V2X-based vehicle cooperative braking method provided by the method embodiment of the present application, execute the step of any combination of the method embodiment, and has the corresponding functions and beneficial effects of the method.

[0086] The embodiment of the present application further provides a computer program product, comprising a computer program, and the computer program implements the above-mentioned V2X-based vehicle cooperative braking method when executed by a processor.

[0087] It can be understood that the contents in the above method embodiments are all applicable to the program product embodiments, the program product embodiments specifically implement the functions same as those of the above method embodiments, and achieve the same beneficial effects as those of the above method embodiments.

[0088] Memory, as used in the specification, includes both volatile and nonvolatile memory, and can include but is not limited to volatile memory (e.g., random access memory (RAM)) and non-volatile memory (e.g., read-only memory (ROM)). Additionally, memory can include a storage device, such as a hard disk drive or a solid state drive. Memory can also include removable media, such as a floppy disk, a CD-ROM, a DVD-ROM, a Blu-ray disk, a flash drive, or magnetic tape. Memory can also include a database, a database server, a database engine, or a database management system. Memory can also include a computer-readable medium, which can be a computer-readable storage medium or a computer-readable communication medium. Memory can include a computer-readable storage medium, which can be a volatile or non-volatile memory, a removable or non-removable memory, or a combination thereof. Memory can include a computer-readable communication medium, which can be a computer-readable medium that includes a signal, a carrier wave, or a computer-readable instruction set. Memory can also include a computer-readable medium that includes a computer program product, which can be a computer program propagated on or fixed in a carrier wave, a computer program propagated on or fixed in a computer-readable medium, or a computer program propagated on or fixed in a computer-readable storage medium.

[0089] The embodiments described in the specification of the present application are intended to be illustrative of the technical solutions provided by the present application, and do not constitute a limitation on the technical solutions provided by the present application. It is known to those skilled in the art that, as technology evolves and new application scenarios appear, the technical solutions provided by the present application are also applicable to similar technical problems.

[0090] The terms "first", "second", "third", "fourth" and the like in the specification of the present application and in the above-described drawings (if any) are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0091] In some alternative embodiments, the functions / operations mentioned in the block diagram can not occur in the order mentioned in the operation diagram. For example, depending on the functions / operations involved, two blocks shown in succession can actually be performed substantially simultaneously or the above-mentioned blocks can sometimes be performed in reverse order. In addition, the embodiments presented and described in the flowcharts of the present application are provided by way of example, with the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operations and logical flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of a larger operation are independently performed.

[0092] Furthermore, although the present application is described in the context of functional modules, it is to be understood that one or more of the functions and / or features described above can be integrated in a single physical device and / or software module, or one or more functions and / or features can be implemented in separate physical devices or software modules. It will also be appreciated that detailed discussion of the actual implementation of each module is unnecessary to an understanding of the present application. Rather, the actual implementation of the modules, in conjunction with their attributes, functions, and internal relationships, are to be understood within the context of the devices disclosed herein. Thus, those skilled in the art with access to the teachings presented herein will be able to devise suitable implementations of the present application without undue experimentation. It is also to be understood that the particular concepts disclosed are merely illustrative and are not intended to limit the scope of the present application, which is defined by the appended claims and equivalents thereof.

[0093] If the above functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the above-mentioned methods according to the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0094] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, which can be specifically embodied in any computer readable medium for use by an instruction execution system, device or apparatus, such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from the instruction execution system, device or apparatus, or in conjunction with these instructions execution system, device or apparatus. For the purpose of this specification, "computer readable medium" can be any device that can contain, store, communicate, propagate or transport programs for use by an instruction execution system, device or apparatus, or in conjunction with these instruction execution system, device or apparatus.

[0095] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can also be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example, via optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.

[0096] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware which are stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their combinations can be used: discrete logic circuitry having logic gates for implementing logic functions upon an application of data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0097] In the above description of the present specification, the description referring to the terms "one embodiment", "another embodiment", or "certain embodiments" or the like means that a specific feature, structure, material or characteristic described in connection with the embodiments or examples is included in at least one embodiment or example of the present application. The illustrative expressions of the above terms do not necessarily refer to the same embodiment or example in the present specification. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0098] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, alternatives and variations to these embodiments can be made without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

[0099] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the above-described embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present application, and these equivalent modifications or substitutions are included in the scope of the claims of the present application.

Claims

1. A V2X-based vehicle cooperative braking method, characterized in that, Includes the following steps: When the vehicle detects an obstacle ahead, it calculates the first collision time based on the obstacle information and determines the desired deceleration based on the first collision time. When the first collision time is less than a preset first threshold, a coordinated braking request is generated based on the first position of the preceding vehicle, the first vehicle speed and the desired deceleration, and the coordinated braking request is broadcast via V2X. If the preceding vehicle receives a coordinated braking response from the following vehicle, it controls the preceding vehicle to brake at the desired deceleration. If the preceding vehicle does not receive the coordinated braking response, it adjusts the desired deceleration to obtain a target deceleration, controls the preceding vehicle to brake at the target deceleration, and issues an audible and visual warning.

2. The V2X-based vehicle cooperative braking method according to claim 1, characterized in that, The vehicle cooperative braking method further includes the following steps: When the following vehicle receives the coordinated braking request, the second collision time is calculated based on the second position and second speed of the following vehicle and the coordinated braking request, and the pre-braking deceleration is determined based on the second collision time; The vehicle behind is controlled to pre-brake according to the pre-braking deceleration, and a cooperative braking response is generated based on the pre-braking deceleration. The cooperative braking response is then returned to the vehicle in front via V2X.

3. The V2X-based vehicle cooperative braking method according to claim 1, characterized in that, The obstacle information includes the obstacle position and obstacle velocity. The step of calculating the first collision time based on the obstacle information and determining the desired deceleration based on the first collision time specifically includes: A first relative distance is determined based on the position of the obstacle and the first position of the vehicle in front; The first relative speed is determined based on the speed of the obstacle and the first speed of the vehicle in front; The first collision time is calculated based on the first relative distance and the first relative velocity; The minimum deceleration is calculated based on the first relative distance, the first vehicle speed, and the preset minimum safe distance; The corresponding first braking coefficient is determined based on the first collision time and a preset front vehicle braking coefficient mapping table. The desired deceleration is determined based on the minimum deceleration and the first braking coefficient; Wherein, the first braking coefficient is greater than 1.

4. The V2X-based vehicle cooperative braking method according to claim 3, characterized in that, The first collision time is determined by the following formula: in, Indicates the time of the first collision. Indicates the first relative distance. Indicates the first vehicle speed. Indicates the speed of the obstacle; The minimum deceleration is determined by the following formula: in, Indicates the minimum deceleration. Indicates the minimum safe distance; The desired deceleration is determined by the following formula: in, Indicates the expected deceleration. Indicates the first braking coefficient. This represents the maximum deceleration corresponding to the current road surface adhesion coefficient.

5. A V2X-based vehicle cooperative braking method according to claim 2, characterized in that, The step of calculating the second collision time based on the second position and second speed of the following vehicle and the cooperative braking request, and determining the pre-braking deceleration based on the second collision time, specifically includes: The coordinated braking request is parsed to obtain the first position, the first vehicle speed, and the desired deceleration; Determine the second relative distance based on the first position and the second position; The second relative speed is determined based on the first vehicle speed and the second vehicle speed; The second collision time is calculated based on the second relative distance, the second relative velocity, and the desired deceleration. The corresponding second braking coefficient is determined based on the second collision time and the preset rear vehicle braking coefficient mapping table; The pre-braking deceleration is determined based on the desired deceleration and the second braking coefficient; The second braking coefficient is less than 1.

6. A V2X-based vehicle cooperative braking method according to claim 5, characterized in that, The second collision time is determined by the following formula: in, Indicates the time of the second collision. Indicates the second relative distance. Indicates the second relative velocity. Indicates the expected deceleration; The pre-braking deceleration is determined by the following formula: in, Indicates pre-braking deceleration. Indicates the first braking coefficient. This represents the maximum deceleration corresponding to the current road surface adhesion coefficient.

7. A V2X-based vehicle cooperative braking method according to claim 1, characterized in that, The process of adjusting the desired deceleration to obtain the target deceleration specifically includes: The second position and second speed of the following vehicle are obtained through roadside equipment; Determine the second relative distance based on the first position and the second position; The second relative speed is determined based on the first vehicle speed and the second vehicle speed; The second collision time is calculated based on the second relative distance, the second relative velocity, and the desired deceleration. The minimum braking time of the following vehicle is determined based on the second vehicle speed, and the collision time safety range is determined based on the minimum braking time and the preset driver reaction time range. The target adjustment coefficient is determined based on the second collision time and the collision time safety interval; The target deceleration is determined based on the desired deceleration and the target adjustment coefficient.

8. A V2X-based vehicle cooperative braking method according to claim 7, characterized in that, The minimum braking duration is determined by the following formula: in, Indicates the minimum braking duration. Indicates the second speed. This indicates the maximum deceleration corresponding to the current road surface adhesion coefficient; The safe collision time interval is determined by the following formula: in, and The lower and upper limits of the safe collision time interval, respectively. This indicates the lower and upper limits of the driver's reaction time interval; The target adjustment coefficient is determined by the following formula: in, Indicates the target adjustment factor. Indicates the time of the second collision; The target deceleration is determined by the following formula: in, Indicates the target deceleration. Indicates the expected deceleration. This indicates the minimum deceleration required to ensure that the vehicle in front does not collide with an obstacle ahead.

9. A V2X-based vehicle cooperative braking device, characterized in that, include: The desired deceleration determination module is used to detect an obstacle ahead, calculate the first collision time based on the obstacle information, and determine the desired deceleration based on the first collision time. The coordinated braking request module is used to generate a coordinated braking request based on the first position of the preceding vehicle, the first vehicle speed, and the desired deceleration when the first collision time is less than a preset first threshold, and to broadcast the coordinated braking request via V2X. The braking control module is used to control the preceding vehicle to brake at the desired deceleration if the preceding vehicle receives a coordinated braking response from the following vehicle, and to adjust the desired deceleration to obtain a target deceleration if the preceding vehicle does not receive the coordinated braking response, and to control the preceding vehicle to brake at the target deceleration and provide an audible and visual warning.

10. An electronic device, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements a V2X-based vehicle cooperative braking method as described in any one of claims 1 to 8.

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