A method and system for multi-vehicle coordinated braking control to ensure safe distance between vehicles

Abstract

This invention belongs to the field of autonomous driving technology and relates to a multi-vehicle cooperative braking control method, system, and readable medium for ensuring safe distances between vehicles. The method includes the following steps: acquiring the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and adjacent vehicles respectively; determining whether the vehicles are engaged in multi-vehicle cooperative braking based on the acceleration, velocity, and displacement of the vehicle, lead vehicle, and adjacent vehicles; if not, returning to the previous step; if engaged, proceeding to the next step; calculating the reference braking torque of the vehicle, and braking based on the reference braking torque; and performing real-time braking operations on all vehicles through multi-vehicle cooperative braking. It employs a road scene recognition module to adjust the safe distance strategy online based on the current road scene, balancing road safety and traffic efficiency, and is applicable to various road scenarios.

Description

Technical Field

[0001] This invention relates to a multi-vehicle cooperative braking control method, system, and readable medium for ensuring safe distances between vehicles, belonging to the field of vehicle autonomous driving technology. Background Technology

[0002] Multi-vehicle cooperative control is an effective way to improve traffic efficiency and ensure driving safety, and it is an important development direction for the intelligentization of the automotive industry. The main idea of ​​multi-vehicle cooperative control is to design an onboard distributed controller to achieve speed tracking of oncoming vehicles while maintaining an effective safe distance between vehicles, thus avoiding collisions within the multi-vehicle system. Currently, multi-vehicle cooperative control shows significant market potential, especially in the commercial vehicle transportation sector, where it can significantly reduce labor transportation costs, improve traffic efficiency, and ensure driving safety.

[0003] Braking process control is crucial for multi-vehicle systems, significantly impacting their driving safety. However, multi-vehicle braking systems face challenges such as multi-source braking medium coupling, heterogeneous braking response differences, difficulties in abstracting mathematical models, and significant interference from complex disturbances, increasing the difficulty of developing multi-vehicle cooperative braking control technology. Therefore, designing a multi-vehicle cooperative braking control method and system that can rigorously guarantee driving safety is an urgent problem to be solved.

[0004] Existing multi-vehicle cooperative braking control technologies are mainly based on the technical approaches of queue stability and multi-agent consistency. Queue stability refers to the continuous attenuation of the car-following error between vehicles during the transmission of the multi-vehicle system from front to back after a disturbance; it has stringent requirements on the initial position error of the multi-vehicle system, which is difficult to achieve in practice. The consistency-based technical approach currently mainly uses distributed linear control technology. Some publicly available multi-vehicle cooperative control technologies that consider the safety distance constraints between vehicles adopt preset performance control technology, which has potential singularity problems and can easily induce instability in the multi-vehicle cooperative control system, leading to vehicle collision accidents. Summary of the Invention

[0005] To address the aforementioned issues, the present invention aims to provide a multi-vehicle cooperative braking control method, system, and readable medium that ensures safe distances between vehicles. It employs a road scene recognition module to adjust the safe distance strategy online based on the current road scene in which the vehicles are located, thus balancing road driving safety and traffic efficiency, and is applicable to various road scenarios.

[0006] To achieve the above objectives, the present invention proposes the following technical solution: a multi-vehicle cooperative braking control method for ensuring safe distance between vehicles, comprising the following steps: acquiring the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle respectively; determining whether the vehicles are in multi-vehicle cooperative braking based on the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle; if not in multi-vehicle cooperative braking, returning to the previous step; if in multi-vehicle cooperative braking, proceeding to the next step; calculating the reference braking torque of the vehicle, and braking the vehicle according to the reference braking torque; and performing real-time braking operation on all vehicles through multi-vehicle cooperative braking.

[0007] Furthermore, the formula for determining whether multiple vehicles are engaged in multi-vehicle cooperative braking is as follows:

[0008]

[0009] Among them, f lag It is a multi-vehicle coordinated braking indicator, f lag =1 indicates that the multi-vehicle system is currently in cooperative braking mode, f lag =0 indicates that the multi-vehicle system is not currently engaged in coordinated braking, P dl0bra It is the opening of the brake pedal of the lead vehicle, P dlLim It is the brake pedal opening threshold value, P dldLim It is the first derivative threshold value of the brake pedal opening; t 0bra It is the continuous braking time of the lead car, T Limit It is the critical value for coordinated braking time.

[0010] Furthermore, the method for calculating the reference braking torque of the vehicle is as follows: A multi-vehicle communication topology is established; based on the multi-vehicle communication topology, the current road scenario of the vehicle is identified online, and a safe distance strategy between vehicles is obtained according to the road scenario; based on the safe distance strategy, a multi-vehicle system model and control objective are established, and the composite displacement error of the multi-vehicle cooperative braking process is calculated; based on the road scenario, a hard funnel constraint for the composite displacement error is established, and the composite displacement error is converted into an unconstrained form; unknown disturbance terms in the multi-vehicle system cooperative braking process are observed online, and the reference braking torque of the vehicle is calculated based on the unknown disturbance terms; it is determined whether regenerative braking is working. If regenerative braking is not working, the regenerative braking torque is set to zero; if regenerative braking is working, the front axle braking torque, rear axle braking torque, regenerative braking torque, and friction braking torque are allocated according to the reference braking torque of the vehicle.

[0011] Furthermore, the workshop safety distance strategy adopts a variable headway safety distance strategy, the calculation formula of which is:

[0012]

[0013] Wherein, Δp0 and Δp iThese are the minimum safe distance and the safe distance for the i-th vehicle, respectively; h 0i It is the absolute headway parameter, h 1i It is the relative headway parameter; h i (tv i (t) v i-1 (t) is the headway; Δp0, h 0i and h 1i These are all parameters related to the road scene, v i (t) is the speed of the following car i.

[0014] Furthermore, the formula for the multi-vehicle system model is:

[0015]

[0016] Where, p i and v i These are the displacement and speed of the following vehicle i, respectively; T Mi It is the total braking torque following vehicle i; M i g Ti and r i These are the mass of the following vehicle i, the overall reduction ratio, and the effective wheel radius; This is the position disturbance term of the following vehicle i; for the following vehicle i, the formula for the control objective of the cooperative braking process is:

[0017]

[0018] Where p0 and v0 are the displacement and velocity of the lead vehicle, respectively, and Δp i v is the safe distance for the i-th vehicle. i (t) is the speed of the following car i.

[0019] Furthermore, the formula for calculating the composite displacement error during multi-vehicle cooperative braking is as follows:

[0020]

[0021] Where, σ pi and σ vi These are the composite displacement error of the following vehicle i and its first derivative term; Δp i0 and Δp ij These are the safe distances from following vehicle i to the lead vehicle and from following vehicle j, respectively. ij Q is the information exchange flag between following vehicle i and following vehicle j. i It is a flag for information exchange between the following vehicle and the lead vehicle.

[0022] Furthermore, the formula for calculating the composite displacement error in its unconstrained form is as follows:

[0023]

[0024] Among them, l i It is the transformed Funnel error variable, φ pi (t) is the Funnel performance function.

[0025] Furthermore, the formula for calculating the reference braking torque of the vehicle is:

[0026]

[0027] Among them, T Mi It is the reference braking torque of the vehicle, M i g Ti and r i These are the mass of the following vehicle i, the overall reduction ratio, and the effective wheel radius, β. DXC1 β DXC2 β DXC3 k DXCi1 k DXCi2 and k DXCi3 All are positive numbers; S DXSi It is a sliding mode variable; It is the position disturbance term following vehicle i. ∏ ij Q is the information exchange flag between following vehicle i and following vehicle j. j It is a flag indicating information exchange between the following vehicle (j) and the lead vehicle. σ pi and σ vi These are the composite displacement error of the following vehicle i and its first derivative, where v0 is the velocity of the lead vehicle, and φ is the velocity of the lead vehicle. pi It is a Funnel performance function. Both Ψ(·) and Ψ(·) are nonlinear functions; sign(·) is a sign function; β DXS It is a constant, l i It is the transformed Funnel error variable.

[0028] This invention also discloses a multi-vehicle cooperative braking control system for ensuring safe distances between vehicles, comprising: a data acquisition module for acquiring the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle respectively; a cooperative braking triggering module for determining whether the vehicles are in multi-vehicle cooperative braking based on the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle; if not in multi-vehicle cooperative braking, returning to the previous step; if in multi-vehicle cooperative braking, proceeding to the next step; and a composite braking module for calculating the reference braking torque of the vehicle, and braking the vehicle based on the reference braking torque, thereby enabling real-time braking operation for all vehicles through multi-vehicle cooperative braking.

[0029] The present invention also discloses a computer-readable storage medium storing a computer program, which is executed by a processor to implement any of the above-mentioned multi-vehicle cooperative braking control methods for ensuring safe distance between vehicles.

[0030] The present invention has the following advantages due to the adoption of the above technical solutions:

[0031] 1. This invention employs a road scene recognition module, which adjusts the safe distance strategy online based on the current road scene in which the vehicle is located. This approach can balance road driving safety and traffic efficiency and is applicable to various road scenarios.

[0032] 2. This invention adopts a composite error hard funnel constraint module, which integrates safety distance constraints into the design of multi-vehicle system cooperative braking control algorithm. This enables multi-vehicle system cooperative braking control that strictly guarantees the safety distance between vehicles, greatly improving the safety of multi-vehicle system cooperative braking process.

[0033] 3. This invention employs an interference observation module, which can quickly estimate unknown disturbance terms in a multi-vehicle system and perform feedforward compensation, exhibiting strong robustness and adaptability to complex environments. Attached Figure Description

[0034] Figure 1 This is a flowchart of a multi-vehicle cooperative braking control method for ensuring safe distance between vehicles in an embodiment of the present invention;

[0035] Figure 2 This is a flowchart illustrating the calculation of the reference braking torque of the vehicle in the multi-vehicle system cooperative braking control process according to one embodiment of the present invention.

[0036] Figure 3 This is a structural diagram of a multi-vehicle cooperative braking control system that ensures safe distance between vehicles in another embodiment of the present invention. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is described in detail through specific embodiments. However, it should be understood that the specific embodiments are provided only for a better understanding of the present invention and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terminology used is for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] To address the problems in existing technologies, such as stringent requirements for initial position errors in multi-vehicle systems and potential singularities in multi-vehicle cooperative control systems that rely on preset performance control techniques to account for safe distance constraints, which can easily induce instability in the multi-vehicle cooperative control system and lead to vehicle collisions, this invention proposes a multi-vehicle cooperative braking control method, system, and readable medium that ensures safe distances between vehicles. This method acquires the vehicle's acceleration, velocity, and displacement using sensors; it also acquires the acceleration, velocity, and displacement of the lead vehicle and adjacent vehicles using a communication device. Based on this, a cooperative braking triggering device determines whether the multi-vehicle system is in cooperative braking mode. If cooperative braking is in effect, the cooperative braking control device calculates the vehicle's reference braking torque under a given hard constraint of safe distance. A composite braking device applies braking to the vehicles based on the reference braking torque, achieving cooperative braking control of the multi-vehicle system. Finally, a storage device backs up the multi-vehicle cooperative braking process data. This invention can be widely applied in the field of multi-vehicle cooperative braking. It employs a road scene recognition module to adjust the safe distance strategy online based on the current road scene, balancing road safety and traffic efficiency, and is applicable to various road scenarios. The present invention will now be described in detail with reference to the accompanying drawings and through embodiments.

[0039] Example 1

[0040] This implementation discloses a multi-vehicle cooperative braking control method to ensure safe distance between vehicles, such as... Figure 1 As shown, it includes the following steps:

[0041] S1 obtains the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle, respectively.

[0042] The data acquisition module acquires the vehicle's own acceleration, velocity, and displacement; it also acquires the acceleration, velocity, and displacement of the lead vehicle and neighboring vehicles. The data acquisition module includes sensors and an on-board communication device. The sensors acquire the vehicle's own acceleration, velocity, and displacement; the on-board communication device acquires the acceleration, velocity, and displacement of the lead vehicle and neighboring vehicles.

[0043] S2 determines whether multiple vehicles are in coordinated braking based on the acceleration, speed, and displacement of the vehicle, the lead vehicle, and the adjacent vehicles. If they are not in coordinated braking, it returns to the previous step; if they are in coordinated braking, it proceeds to the next step.

[0044] The formula for determining whether multiple vehicles are engaged in coordinated braking is as follows:

[0045]

[0046] Among them, f lag It is a multi-vehicle coordinated braking indicator, f lag =1 indicates that the multi-vehicle system is currently in cooperative braking mode, f lag=0 indicates that the multi-vehicle system is not currently engaged in coordinated braking, P dl0b It is the opening of the brake pedal of the lead vehicle, P dlLim It is the brake pedal opening threshold value, P dldLim It is the first derivative threshold value of the brake pedal opening; t 0bra It is the continuous braking time of the lead car, T Limit It is the critical value for coordinated braking time.

[0047] S3 calculates the reference braking torque of the vehicle under a given hard constraint of safe distance. The vehicle brakes according to the reference braking torque. Through multi-vehicle cooperative braking, the braking operation of all vehicles is performed in real time, and the data generated in the multi-vehicle cooperative braking process is stored.

[0048] like Figure 2 As shown, the method for calculating the reference braking torque of a vehicle under a given hard constraint of safe distance includes the following steps:

[0049] S3.1 Define the multi-vehicle communication topology; based on the multi-vehicle communication topology, identify the road scene where the current vehicle is located online, and obtain the vehicle-to-vehicle safe distance strategy according to the road scene.

[0050] In this embodiment, rule-based or deep learning technologies are used to identify the road scene where the vehicle is currently located online. Typical scenarios include, but are not limited to, urban congested driving scenarios, urban low-speed driving scenarios, suburban road driving scenarios, and highway driving scenarios.

[0051] The safe distance strategy for obtaining the workshop distance based on the road scenario adopts a variable headway safe distance strategy, and its calculation formula is as follows:

[0052]

[0053] Wherein, Δp0 and Δp i These are the minimum safe distance and the safe distance for the i-th vehicle, respectively; h 0i It is the absolute headway parameter, h 1i It is a relative headway parameter, and h 0i ,h 1i >0 is a positive constant; h i (tv i (t) v i-1 (t) is the headway; Δp0, h 0i and h 1i These are all parameters related to the road scene, v i (t) is the speed of the following vehicle i. The above parameters can be dynamically set according to the road scenario in which the multi-vehicle system is located.

[0054] S3.2 Based on the workshop safety distance strategy, establish a multi-vehicle system model and control target, and calculate the composite displacement error of the multi-vehicle cooperative braking process.

[0055] Establish a multi-vehicle system model and control objective, where the formula for the multi-vehicle system model is:

[0056]

[0057] Where, p i and v i These are the displacement and speed of the following vehicle i, respectively; T Mi It is the total braking torque following vehicle i; M i g Ti and r i These are the mass of the following vehicle i, the overall reduction ratio, and the effective wheel radius; It is the position disturbance term of the following vehicle i; the position disturbance term of the following vehicle i includes, but is not limited to, parameter uncertainty and time-varying external disturbances.

[0058] For the following vehicle i, the formula for the control objective of the cooperative braking process is:

[0059]

[0060] Where p0 and v0 are the displacement and velocity of the lead vehicle, respectively, and Δp i v is the safe distance for the i-th vehicle. i (t) is the speed of the following car i.

[0061] The formula for calculating the composite displacement error during multi-vehicle coordinated braking is as follows:

[0062]

[0063] Where, σ pi and σ vi These are the composite displacement error of the following vehicle i and its first derivative term; Δp i0 and Δp ij These are the safe distances from following vehicle i to the lead vehicle and from following vehicle j, respectively. ij Q is the information exchange flag between following vehicle i and following vehicle j. i It is a flag for information exchange between the following vehicle and the lead vehicle.

[0064] In this embodiment,

[0065] ∏ ij The specific formula for the information exchange flag between following vehicle i and following vehicle j is as follows:

[0066]

[0067] Q i This is the information exchange flag between the following vehicle (i) and the lead vehicle. The specific formula is as follows:

[0068]

[0069] The equations for the composite displacement error and the first-order derivative term of the following vehicle i are constructed as follows:

[0070]

[0071] S3.3 Based on the road scenario, a hard funnel constraint is formulated for the composite displacement error, and the composite displacement error is converted into an unconstrained form.

[0072] In this embodiment, based on the road scenario, a hard Funnel performance constraint for composite displacement error is formulated, and the specific formula is as follows:

[0073] -φ pi (t)≤σ pi ≤+φ pi (t)

[0074] Where, +φ pi (t) and -φ pi (t) represents the upper and lower boundaries of the composite displacement error of the following vehicle i, respectively, and the specific formula is as follows:

[0075]

[0076] Where, φ pi0 φ pi∞ and These are the Funnel performance functions φ pi Initial value, final value, and convergence rate of φ; pi0 φ pi∞ and These are all parameters related to the road scene and can be dynamically set according to the current road scene of the multi-vehicle system.

[0077] The formula for calculating composite displacement error in unconstrained form is as follows:

[0078]

[0079] Among them, l i It is the transformed Funnel error variable, φ pi (t) is the Funnel performance function. The first and second derivative terms of the transformed Funnel error variable are expressed as follows:

[0080]

[0081] in,

[0082] S3.4 Observe the unknown disturbance terms in the cooperative braking process of the multi-vehicle system online, and calculate the reference braking torque of the vehicle based on the unknown disturbance terms.

[0083] In this embodiment, a fixed-time disturbance observer is used to observe the unknown disturbance term during the cooperative braking process of the multi-vehicle system. The specific formula is as follows:

[0084]

[0085] in, and These are the system state σ pi σ vi and The estimated value, It is state σ pi The estimation error, κ DXOj >0, j=1,2,3,4,5,6 are positive constants; α DXOj >0, j=1,2,3, and α DXOj =j(α) DXO -1)+1, α DXO ∈(0 1) are positive constants; β DXOj >1, j=1,2,3, and β DXOj =j(β) DXO -1)+1,β DXO ∈(0 1) are positive constants; It is a positive number; sign(·) is the sign function.

[0086] The formula for calculating the reference braking torque of a vehicle is:

[0087]

[0088] Among them, T Mi It is the reference braking torque of the vehicle, M i g Ti and r i These are the mass of the following vehicle i, the overall reduction ratio, and the effective wheel radius, β. DXC1 β DXC2 β DXC3 k DXCi1 k DXCi2 and k DXCi3 All are positive constants, β DXC1 >1, β DXC1 β DXC2 <1、β DXC1 β DXC3 >1、k DXCi1 >1、kDXCi2 >0 and k DXCi3 >0;S DXSi It is a sliding mode variable; It is the position disturbance term following vehicle i. ∏ ij Q is the information exchange flag between following vehicle i and following vehicle j. j It is a flag indicating information exchange between the following vehicle (j) and the lead vehicle. σ pi and σ vi These are the composite displacement error of the following vehicle i and its first derivative, where v0 is the velocity of the lead vehicle, and φ is the velocity of the lead vehicle. pi It is a Funnel performance function. Both Ψ(·) and Ψ(·) are nonlinear functions; sign(·) is a sign function; β DXS It is a constant, l i It is the transformed Funnel error variable.

[0089] S DXSi It is the sliding mode variable, and its specific formula is:

[0090]

[0091] in,

[0092] K DXSa ,K DXSb >0, ρ DXS ,β DXs >1, p DXS and q DXS It is a positive constant that satisfies q DXS ρ DXS >1 and

[0093] And Ψ(·) are nonlinear functions, and their specific formulas are as follows:

[0094]

[0095]

[0096] S3.5 Determine whether regenerative braking is working. If regenerative braking is not working, the regenerative braking torque is set to zero. If regenerative braking is working, the front axle braking torque, rear axle braking torque, regenerative braking torque, and friction braking torque are distributed according to the vehicle's reference braking torque.

[0097] The front axle braking torque and rear axle braking torque are distributed using the I-curve; the regenerative braking torque and friction braking torque are distributed according to the principle of prioritizing regenerative braking and compensating for friction braking, as shown in the following formula:

[0098]

[0099] Among them, T lim It is the motor torque boundary, T MBi It is the regenerative braking torque, T HBi It is the friction braking torque.

[0100] Example 2

[0101] Based on the same inventive concept, this embodiment discloses a multi-vehicle cooperative braking control system for ensuring safe distances between vehicles, such as... Figure 3 As shown, it includes: a data acquisition module, a cooperative braking triggering module, and a composite braking module;

[0102] The data acquisition module is used to acquire the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle respectively. The data acquisition module includes a sensing device 1 and an on-board communication device 2. The sensor 1 acquires the driving acceleration, velocity, and displacement of the vehicle, and the on-board communication device 2 acquires the driving acceleration, velocity, and displacement of the lead vehicle and the adjacent vehicle.

[0103] The coordinated braking trigger module includes a coordinated braking trigger device 3, which is used to determine whether multiple vehicles are in coordinated braking based on the acceleration, speed and displacement of the vehicle, the lead vehicle and the adjacent vehicle. If they are not in coordinated braking, the system returns to the previous step; if they are in coordinated braking, the system proceeds to the next step.

[0104] The composite braking module is used to calculate the reference braking torque of the vehicle itself. The vehicle brakes based on this reference braking torque, and through multi-vehicle coordinated braking, real-time braking operations are performed on all vehicles. The composite braking module includes a coordinated braking control device 4, a composite braking device 5, and a storage device 6. The coordinated braking control device 4 is used to calculate the reference braking torque of the vehicle itself based on the operating status of the vehicle, the lead vehicle, and adjacent vehicles. The composite braking device 5 is used for the vehicle itself to brake based on its reference braking torque, and real-time braking operations are performed on all vehicles through multi-vehicle coordinated braking. The storage device 6 is used to store the multi-vehicle system coordinated braking process data.

[0105] In this embodiment, the cooperative braking control device 4 specifically includes a communication topology design module 41, a road scene recognition module 42, a safety distance design module 43, a composite error calculation module 44, a composite error hard constraint module 45, a composite error conversion module 46, an interference observation module 47, a reference braking torque calculation module 48, a regenerative braking torque enabling module 49, and a braking torque distribution module 410. The communication topology design module 41 is used to formulate the communication topology of the multi-vehicle system. The road scene recognition module 42 determines the road scene where the vehicle is located based on the vehicle's operating status. Based on the current road scene, the safety distance design module 43 formulates a safety distance strategy for the corresponding scene. The composite displacement error calculation module 44 is used to calculate the composite displacement error during the cooperative braking process of the multi-vehicle system; the composite error hard constraint module 45 designs the composite displacement error constraint under the current road scenario; the composite error conversion module 46 converts the constrained composite error into an unconstrained error form; the disturbance observation module 47 is used to estimate the unknown disturbance term of the system; the reference braking torque calculation module 48 is used to calculate the total reference braking torque of the vehicle; the regenerative braking torque enabling module 49 is used to determine whether the current regenerative braking motor is working; the braking torque distribution module 410 is used to distribute the front axle braking torque, rear axle braking torque, regenerative braking torque and friction braking torque.

[0106] Example 3

[0107] Based on the same inventive concept, this embodiment discloses a computer-readable storage medium storing a computer program, which is executed by a processor to implement any of the above-mentioned multi-vehicle cooperative braking control methods for ensuring safe distance between vehicles.

[0108] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0109] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0110] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0111] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific embodiments of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention. The above content is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A multi-vehicle cooperative braking control method for ensuring safe distance between vehicles, characterized in that, Includes the following steps: Obtain the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle respectively; Based on the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicle, determine whether the multiple vehicles are in multi-vehicle cooperative braking. If they are not in multi-vehicle cooperative braking, return to the previous step; if they are in multi-vehicle cooperative braking, proceed to the next step. The reference braking torque of the vehicle is calculated, and the vehicle brakes according to the reference braking torque. Through the multi-vehicle coordinated braking, the braking operation of all vehicles is performed in real time. The method for calculating the reference braking torque of a vehicle is as follows: Develop a multi-vehicle communication topology; Based on the multi-vehicle communication topology, the road scene where the current vehicle is located is identified online, and a safe distance strategy between vehicles is obtained according to the road scene. Based on the workshop safety distance strategy, a multi-vehicle system model and control target are established, and the composite displacement error of the multi-vehicle cooperative braking process is calculated. Based on the road scenario, a hard funnel constraint for the composite displacement error is formulated, and the composite displacement error is converted into an unconstrained form. The unknown disturbance terms of the multi-vehicle system's cooperative braking process are observed online, and the reference braking torque of the vehicle is calculated based on the unknown disturbance terms. Determine whether regenerative braking is working. If regenerative braking is not working, the regenerative braking torque is set to zero. If regenerative braking is working, the front axle braking torque, rear axle braking torque, regenerative braking torque, and friction braking torque are distributed according to the vehicle's reference braking torque.

2. The multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in claim 1, characterized in that, The formula for determining whether multiple vehicles are in a state of coordinated braking is as follows: in, It is a multi-vehicle coordinated braking indicator. This indicates that the multi-vehicle system is currently in coordinated braking mode. This indicates that the multi-vehicle system is not currently engaged in coordinated braking. It refers to the opening of the brake pedal of the lead vehicle. It is the brake pedal opening threshold value. It is the first derivative threshold value of the brake pedal opening; It is the continuous braking time of the lead vehicle. It is the critical value for coordinated braking time.

3. The multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in claim 1, characterized in that, The workshop safety distance strategy adopts a variable headway safety distance strategy, and its calculation formula is as follows: in, and They are the first i Minimum safe distance and safe distance between vehicles; It is the absolute headway parameter. It is a relative headway parameter; It is the headway; , and These are all parameters related to the road scene. It is a following vehicle i The speed of travel.

4. The multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in claim 1, characterized in that, The formula for the multi-vehicle system model is: in, and They are following vehicles i The displacement and velocity of the journey; It is a following vehicle i Total braking torque; , and They are following vehicles i Mass, overall reduction ratio, and effective wheel radius; It is a following vehicle i Position disturbance term; For following vehicles i The formula for the control objective of the coordinated braking process is: in, and These are the displacement and speed of the lead car, respectively. It is the first i Safe distance between vehicles It is a following vehicle i The speed of travel.

5. The multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in claim 1, characterized in that, The formula for calculating the composite displacement error in the multi-vehicle cooperative braking process is as follows: in, and They are following vehicles i The composite displacement error and its first derivative term; and They are following vehicles i To the lead car, following car j Safe distance, It is a following vehicle i and following vehicle j Information exchange flags between them It is a following vehicle i Information exchange marker between the lead vehicle and the vehicle.

6. The multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in claim 5, characterized in that, The formula for calculating the composite displacement error in its unconstrained form is as follows: in, It is the transformed Funnel error variable. It is a Funnel performance function.

7. The multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in claim 6, characterized in that, The formula for calculating the reference braking torque of the vehicle is as follows: in, It is the reference braking torque of the vehicle. , and They are following vehicles i The mass, overall reduction ratio, and effective wheel radius, , , and All are positive numbers; It is a sliding mode variable; It is a following vehicle i The positional disturbance term, , It is a following vehicle i and following vehicle j Information exchange flags between them It is a following vehicle j Information exchange marker between the lead vehicle and the vehicle in the lead vehicle , , and They are following vehicles i The composite displacement error and its first derivative term, That's the speed of the lead car. It is a Funnel performance function. and All are nonlinear functions; It is a symbolic function; ; It is a constant. It is the transformed Funnel error variable.

8. A multi-vehicle cooperative braking control system for ensuring safe distances between vehicles, characterized in that, include: The data acquisition module is used to acquire the acceleration, velocity, and displacement of the vehicle, the lead vehicle, and the adjacent vehicles, respectively. The coordinated braking trigger module is used to determine whether multiple vehicles are in coordinated braking based on the acceleration, speed and displacement of the vehicle, the lead vehicle and the adjacent vehicle; The composite braking module is used to calculate the reference braking torque of the vehicle, and the vehicle brakes according to the reference braking torque. Through the multi-vehicle coordinated braking, real-time braking operation is performed on all vehicles. The method for calculating the reference braking torque of a vehicle is as follows: Develop a multi-vehicle communication topology; Based on the multi-vehicle communication topology, the road scene where the current vehicle is located is identified online, and a safe distance strategy between vehicles is obtained according to the road scene. Based on the workshop safety distance strategy, a multi-vehicle system model and control target are established, and the composite displacement error of the multi-vehicle cooperative braking process is calculated. Based on the road scenario, a hard funnel constraint for the composite displacement error is formulated, and the composite displacement error is converted into an unconstrained form. The unknown disturbance terms of the multi-vehicle system's cooperative braking process are observed online, and the reference braking torque of the vehicle is calculated based on the unknown disturbance terms. Determine whether regenerative braking is working. If regenerative braking is not working, the regenerative braking torque is set to zero. If regenerative braking is working, the front axle braking torque, rear axle braking torque, regenerative braking torque, and friction braking torque are distributed according to the vehicle's reference braking torque.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which is executed by a processor to implement the multi-vehicle cooperative braking control method for ensuring safe distance between vehicles as described in any one of claims 1-7.

Images