Estimation Method for State Change of Following Vehicles Considering Lateral Interference under Two-Lane Driving

Abstract

The present invention discloses a method for estimating the state change of a following vehicle considering lateral interference under two-lane driving. The steps include: S01. Constructing a simulation analysis environment under two-lane driving conditions; S02. Obtaining vehicle trajectory data and lane geometric dimension data and inputting them into the simulation analysis environment to perform vector decomposition to obtain the speed vector of the cutting-in vehicle and the decomposition results of the spacing vector; S03. In the simulation analysis environment, when the cutting-in vehicle starts to enter the target lane, estimating the state change between the cutting-in vehicle and each following vehicle; S04. Calculating the interference factor and the attenuation factor in the simulation analysis environment; S05. Obtaining the influence degree of the lateral interference on the following vehicle and the correlation characteristics between the front and rear vehicles in the following vehicle fleet; S06. Estimating the remaining area of the lane according to the spacing vector. The present invention considers the lateral interference generated by a vehicle cutting into a lane, and can effectively improve the accuracy of analyzing the state change of the following vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of microscopic traffic flow modeling and analysis, and particularly to a method for estimating the state change of following vehicles considering lateral interference under two-lane driving. Background Art

[0002] Under the condition of two-lane driving, affected by the vehicle in the adjacent lane cutting into the target lane, after the following vehicle fleet in the target lane is laterally cut in and interfered, the following behavior of the vehicle will change, the vehicle speed and following distance will change immediately, and the traffic flow characteristics of the following vehicle fleet will also be affected. How to quantify the impact of lateral cutting on the following vehicle and even the following vehicle fleet is of great significance.

[0003] When modeling and analyzing the impact of lateral cutting on following vehicles in microscopic traffic flow modeling, currently, the method of available cutting gap or setting virtual vehicles is usually adopted. For example, some practitioners have proposed a vehicle following model considering lateral offset, which integrates the lateral offset and the hindrance acceleration into the following model, and a cross-following model considering lateral interference, which constructs a staggered following model by introducing the lateral gap of adjacent vehicles to realize the analysis of the change from following behavior to overtaking behavior. However, although the vehicle following models constructed by the above methods consider the influence of the laterally cutting-in vehicle, they only simply consider the changes in one-dimensional parameters such as vehicle distance and speed. When the laterally cutting-in vehicle enters the target lane, it not only reflects the changes in one-dimensional parameters such as vehicle distance and speed, but also involves the influence of the cutting-in vehicle on the following vehicle and the following vehicle fleet, such as the lateral displacement change of the following vehicle, the remaining drivable area of the lane, the headway distance within the fleet, etc. Moreover, the vehicle and traffic flow parameters change with time and are related to the action time of the cutting-in vehicle on the following vehicle fleet. Therefore, when using the above model for analysis, when the cutting-in vehicle enters the target lane and generates a lateral offset, it is actually impossible to quantify the influence on the vehicles in the target lane. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: aiming at the technical problems existing in the prior art, the present invention provides a method for estimating the state change of following vehicles considering lateral interference under two-lane driving, which considers the lateral interference generated by the vehicle cutting into the target lane on the following vehicles in the lane, can improve the accuracy and effectiveness of the speed-spacing analysis of following vehicles, and quantify the influence of the laterally cutting-in vehicle on the following vehicles.

[0005] To solve the above technical problem, the technical solution proposed by the present invention is:

[0006] A method for estimating the state change of following vehicles considering lateral interference under two-lane driving, the steps include:

[0007] Step S01. Construct a simulation analysis environment including a leading vehicle on the target lane, a cutting-in vehicle on the adjacent lane, and a following vehicle on the target lane, for simulating the changes in the speed characteristics of the following vehicle and the vehicle fleet when the cutting-in vehicle cuts into the target lane and generates lateral interference under the condition of two-lane driving;

[0008] Step S02. Obtain the vehicle trajectory data and lane geometric dimension data of the cutting-in vehicle and input them into the simulation analysis environment, extract the instantaneous velocity vector of the cutting-in vehicle when it cuts into the target lane and perform vector decomposition to obtain the decomposition result of the cutting-in vehicle's velocity vector, and extract the instantaneous displacement vector of the cutting-in vehicle when it cuts into the lane, the spacing vectors between the cutting-in vehicle and the front and rear vehicles in the target lane, and after vector decomposition, obtain the decomposition result of the spacing vector between the cutting-in vehicle and the following vehicle in the driving direction;

[0009] Step S03. In the simulation analysis environment, when the cutting-in vehicle starts to enter the target lane, estimate the state changes between the cutting-in vehicle and each following vehicle according to the decomposition result of the cutting-in vehicle's velocity vector, the decomposition result of the spacing vector, and the speed characteristics of the following vehicle;

[0010] Step S04. In the simulation analysis environment, calculate the interference factor and the attenuation factor of the vehicle cutting-in effect in the vehicle fleet composed of all following vehicles. The interference factor is obtained according to the state of the following vehicle and the defined interference state, and the interference state includes the spacing and speed difference between the following vehicle and the cutting-in vehicle. The attenuation factor is obtained according to the defined speed change characteristics of the following vehicle;

[0011] Step S05. According to the interference factor and the attenuation factor, obtain the influence degree of the lateral interference on the displacement and speed of the following vehicle during the process of the cutting-in vehicle entering the following vehicle fleet and the correlation characteristics between the front and rear vehicles in the following vehicle fleet;

[0012] Step S06. Estimate the remaining area of the lane according to the spacing vectors of the cutting-in vehicle, the following vehicle, and the leading vehicle.

[0013] Further, in step S01, in the constructed simulation analysis environment, by analyzing the lateral interference on the first following vehicle in the target lane when the cutting-in vehicle cuts into the target lane according to the vehicle trajectory data, the following characteristics of the first following vehicle and the second following vehicle and the changes in the speed characteristics of the vehicle fleet are evolved by using the following model. The first following vehicle is the nearest following vehicle after the cutting-in vehicle cuts into the target lane, and the second following vehicle is the second nearest following vehicle after the cutting-in vehicle cuts into the target lane.

[0014] Further, when extracting the instantaneous velocity vector of the cutting-in vehicle into the lane and performing vector decomposition in step S02, specifically, the instantaneous velocity vector of the cutting-in vehicle into the lane is extracted for vector decomposition to obtain the tangential direction velocity component and the normal direction velocity component of the vehicle trajectory in a specified period. The steps include:

[0015] Construct a lane coordinate system using the vehicle trajectory data under the constraint of the lane geometric dimensions, define the driving direction as the x-axis direction, the velocity component in the x-axis direction as the driving speed, and the velocity component in the y-axis direction as the cutting-in speed. Define the state vectors of the leading vehicle, the cutting-in vehicle, the first following vehicle, and the second following vehicle within a specified period. The state vectors include displacement vectors, velocity vectors, and acceleration vectors;

[0016] Use the method of vector decomposition to project the state vectors onto the coordinate axes to obtain the projections of the cutting-in vehicle trajectory velocity vector onto the coordinate axis directions, and further obtain the magnitudes of the instantaneous components of the cutting-in vehicle trajectory tangential direction velocity vector on the x and y axes as:

[0017]

[0018] Among them, is the velocity in the tangential direction, is the velocity in the normal direction, and θ 切 is the acute angle formed by the tangential direction of the cutting-in vehicle's instantaneous trajectory and the lane center line direction;

[0019] And obtain the decomposition components of the velocity vectors of the leading vehicle, the first following vehicle, the second following vehicle, and each following vehicle within the vehicle platoon on the x and y axes.

[0020] Further, in step S02, extracting the instantaneous displacement vector of the cutting-in vehicle into the lane and the spacing vectors between the cutting-in vehicle and the front and rear vehicles in the target lane includes:

[0021] Extract the instantaneous displacement vector of the cutting-in vehicle into the lane, use the method of vector decomposition to project the instantaneous displacement vector onto the coordinate axes to obtain the projection of the cutting-in vehicle trajectory displacement vector onto the coordinate axis directions, and obtain the magnitudes of the instantaneous components of the cutting-in vehicle trajectory tangential direction displacement vector on the x and y axes as:

[0022]

[0023] Among them, is the displacement vector in the tangential direction, is the displacement vector in the normal direction, and the vector direction is from the cutting-in vehicle to the queue vehicle direction, is the acute angle between the vehicle driving direction of the cutting-in vehicle and the distance vector, and the magnitude of the component in the x-axis direction is x切x Satisfy:

[0024]

[0025] That is, the magnitude of the component in the x-axis direction is x 切x Maintain the minimum safety threshold to avoid collision between the cutting-in vehicle and the first following vehicle, where is the speed of the first following vehicle, is the acceleration of the first following vehicle;

[0026] According to the velocity vector of the cutting-in vehicle in the x-axis direction The velocity vector of the cutting-in vehicle in the y-axis direction And the velocity vector of the first following vehicle in the x-axis direction The velocity vector of the first following vehicle in the y-axis direction Obtain the spacing vector according to the following formula Parameters that change with time

[0027]

[0028] And according to the projected length of the vehicle body length of the cutting-in vehicle in the x-axis direction of the target lane and the component length of the spacing vector in the x-axis direction, calculate the headway h according to the following formula In the x-axis direction: s :

[0029]

[0030] Wherein, is the displacement vector of the cutting-in vehicle in the x-axis direction, θ 切 Is the acute angle formed by the tangent direction of the instantaneous trajectory of the cutting-in vehicle and the center line direction of the lane.

[0031] Furthermore, the step S03 includes:

[0032] According to the velocity vector of the cutting-in vehicle, the decomposition result of the spacing vector, and the velocity vector of the first following vehicle, use the full speed difference model to estimate the velocity change and position change of the cutting-in vehicle and the first following vehicle in the tangential direction, and obtain the velocity difference and spacing change between the cutting-in vehicle and the first following vehicle. The full speed difference model is:

[0033]

[0034] Wherein, is the acceleration of the nth following vehicle, is the speed of the nth following vehicle, Δx n(t) is the displacement change of the nth following vehicle, a is the sensitivity coefficient, λ is the speed difference weight coefficient, and V(·) is the optimized speed function;

[0035] Use the trajectory data fitting model to estimate the speeds and position changes of the cutting-in vehicle and the first following vehicle in the normal direction, obtain the speed and position change components of the first following vehicle and the cutting-in vehicle in the x-axis and y-axis directions, and then obtain the estimated value of the vehicle trajectory at the next moment, and use the vehicle trajectory data to fit the trajectory curve to predict the change of the direction angle.

[0036] Further, the calculation of the interference factor in step S04 includes:

[0037] Define the state of the first following vehicle using the spacing and speed difference between the first following vehicle and the leading vehicle, and define the interference state using the spacing and speed difference between the interfering vehicle and the following vehicle; in the interference state, the proportion of the displacement of the first following vehicle in the total displacement is defined as P1, and in the following state, the proportion of the displacement of the first following vehicle in the total displacement is defined as (1 - P1). Define the interference parameter α1 of the first following vehicle as:

[0038]

[0039] Using the classical following model and the trajectory data fitting method, obtain the displacement change of the second following vehicle in the x-axis direction, and the lateral displacement of the second following vehicle in the y-axis direction caused by the lateral displacement of the first following vehicle in the y-axis direction, and estimate the trajectory vector of the second following vehicle; define the displacement proportion of the second following vehicle under the longitudinal guidance of the first following vehicle as P2, and the displacement proportion under the lateral influence of the first following vehicle as (1 - P2). Define the interference parameter α2 of the second following vehicle as:

[0040]

[0041] Then, the interference parameter of the ith following vehicle in the following vehicle platoon is obtained as:

[0042]

[0043] In step S05, use α1, α2,..., α i Analyze the influence effect of the cutting-in vehicle on the moving displacement of the following vehicle i in the following vehicle platoon.

[0044] Further, the calculation of the attenuation factor in step S04 includes:

[0045] Use the vehicle speed and position to update the corresponding moment to define the attenuation factor κ of the lateral cut-in on the following vehicle platoon j , that is, the attenuation factor κ jIt is defined that the time period from the deceleration moment of the first following vehicle in the following vehicle platoon to the moment when it accelerates to the target vehicle speed is used as the denominator, and the time period from the deceleration moment of the last affected vehicle j in the platoon to the moment when it accelerates to the target vehicle speed is used as the numerator. The specific calculation formula is as follows:

[0046]

[0047] Among them, the factor κ j has a value range of [0, 1]. When the value is 0, that is, when the first following vehicle in the platoon is in the process of being cut in by the cutting-in vehicle, the cutting-in effect does not decay; when the value starts to appear as 1, that is, the effect brought by the cutting-in vehicle in the following vehicle platoon has completely decayed, that is, the effect does not affect the following vehicle j in the following vehicle platoon, and j corresponds to the vehicle number at the end of the decay of the cutting-in effect of the cutting-in vehicle;

[0048] In the step S05, the attenuation factor κ j is used to analyze the influence effect of the cutting-in vehicle on the vehicle speed of the following vehicles in the following vehicle platoon.

[0049] Furthermore, in the step S05, according to the interference factor and the attenuation factor, the correlation characteristics between the front and rear vehicles in the following vehicle platoon include:

[0050] The correlation characteristics between the front and rear following vehicles in the target lane are described by using the correlation index λ(L), and the change law of the correlation characteristics under normal driving and the condition of interference is obtained. The calculation expression of the correlation index λ(L) is:

[0051]

[0052] Among them, L is the distance between the front and rear vehicles traveling in the same lane in the traveling direction, L min , L max are respectively the minimum distance and the maximum distance between the front and rear vehicles traveling in the same lane in the traveling direction, k is the weight coefficient, and L -1 is the reciprocal of the distance.

[0053] Furthermore, the step S06 includes:

[0054] It is defined that the lane passing area of the first following vehicle is the product of the integral of the vehicle spacing change speed V L (t) and the vehicle width w, that is:

[0055] w·∫V L (t)dt

[0056] Define the cut-in influence area as the rectangle formed by the projection of the length of the cut-in vehicle body in the x-axis direction and the projection of the vehicle width, that is, the calculation expression of the cut-in influence area is:

[0057] (L 切x - ∫v(t)cosθdt)·(w 车道y - ∫v(t)sinθdt)

[0058] where L 切x is the distance between the cut-in vehicle and the following vehicle in the x-axis direction, w 车道y is the lane width of the target lane, v(t) is the speed function of the cut-in vehicle, and θ is the angle between the vehicle cut-in direction and the lane centerline direction;

[0059] Considering the speed projections of the cut-in vehicle in the x and y directions during the cut-in process, the remaining available driving area A of the lane is estimated according to the following formula:

[0060] A = w·∫V L (t)dt - (L 切x - ∫v(t)cosθdt)·(w 车道y - ∫v(t)sinθdt).

[0061] Furthermore, the step S06 further includes obtaining the change law of the remaining area of the target lane during the vehicle cut-in process according to the estimated remaining available driving area of the lane

[0062] Compared with the prior art, the advantages of the present invention are as follows:

[0063] 1. Aiming at the lateral interference phenomenon generated by a vehicle cutting into a target lane on the following vehicle in the target lane, the present invention uses the vector analysis method to obtain the two-dimensional decomposition of the lateral interference, and obtains the two-dimensional decomposition components of the cut-in vehicle speed during the cut-in process, as well as the decomposition results of the distance vector between the cut-in vehicle and the following vehicle in the target lane. It can expand the method of analyzing the following characteristics mainly relying on the single-dimensional parameter of vehicle distance to two dimensions, and then can use the remaining available driving area of the lane to quantify the influence of the lateral interference after cutting in on the following vehicle and the vehicle fleet in the target lane.

[0064] 2. By considering the lateral interference generated by a vehicle cutting into a target lane on the following vehicle in the lane under the two-lane driving condition, combining the vector decomposition method and the following model, the present invention can effectively analyze the changes in the distance and vehicle speed of the following vehicle in the tangential and normal directions under the lateral interference, and accurately estimate the state of the following vehicle in the lane after the vehicle cuts in, that is, the speed-distance change state, and solve the problem of low estimation accuracy in traditional microscopic traffic flow simulation schemes due to only considering the distance in the forward direction of the vehicle and ignoring the lateral distance in actual vehicle driving. Description of the Drawings

[0065] Figure 1 This is a schematic diagram showing the detailed implementation process of the method for estimating the state change of a following vehicle considering lateral interference under two-lane driving in this embodiment.

[0066] Figure 2 This is a schematic diagram showing the principle of following of a lateral interference vehicle under a two-lane scenario in a specific application embodiment of the present invention.

[0067] Figure 3 This is a schematic diagram showing the principle of decomposition of the tangential velocity in the driving trajectory direction of a cutting-in vehicle in a specific application embodiment of the present invention.

[0068] Figure 4 This is a schematic diagram showing the characteristic result of interference parameter obtained in a specific application embodiment of the present invention.

[0069] Figure 5 This is a schematic diagram showing the characteristic result of the change of the attenuation factor obtained in a specific application embodiment of the present invention.

[0070] Figure 6 This is a schematic diagram showing the characteristic result of the correlation curve obtained in a specific application embodiment of the present invention.

[0071] Figure 7 This is a schematic diagram showing the cutting-in projection result of a vehicle on the target lane in a specific application embodiment of the present invention.

[0072] Figure 8 This is a schematic diagram showing the characteristic result of the change of the remaining available passing area of the lane of the following vehicle (following vehicle 1) under the action of lateral interference in a specific application embodiment of the present invention. Detailed Embodiment

[0073] The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0074] As Figure 1 shown, the steps of the method for estimating the state change of a following vehicle considering lateral interference under two-lane driving in this embodiment include:

[0075] Step S01. Construct a simulation analysis environment including a leading vehicle on the target lane, a cutting-in vehicle on the adjacent lane, and a following vehicle on the target lane, so as to simulate the change of the speed characteristics of the following vehicle and the vehicle fleet when the cutting-in vehicle cuts into the target lane and generates lateral interference under the condition of two-lane driving.

[0076] As Figure 2As shown, under the condition of two-lane driving, in this embodiment, the main analysis object is the cutting-in vehicle in the current lane driving into the target lane. When the cutting-in vehicle in the current lane drives into the target lane, a simulation analysis environment is constructed with the leading vehicle, the following vehicle 1 (i.e., the first following vehicle), and the following vehicle 2 (i.e., the second following vehicle) of the following vehicle in the target lane. The following vehicle 1 is the nearest following vehicle after the cutting-in vehicle cuts into the target lane, and the following vehicle 2 is the second nearest following vehicle after the cutting-in vehicle cuts into the target lane. In the simulation analysis environment, according to the vehicle trajectory data analysis, a lateral interference is generated to the following vehicle 1 in the target lane when the vehicle cuts into the target lane. Therefore, the following characteristics of the following vehicle 1 and the following vehicle 2 and the change of the vehicle fleet speed characteristics are evolved by using the following model.

[0077] Step S02. Obtain the vehicle trajectory data and lane geometric dimension data of the cutting-in vehicle and input them into the simulation analysis environment, extract the instantaneous velocity vector of the cutting-in vehicle when it cuts into the lane and perform vector decomposition to obtain the cutting-in vehicle speed vector decomposition result, and extract the instantaneous displacement vector of the cutting-in vehicle when it cuts into the target lane, the spacing vectors between the cutting-in vehicle and the front and rear vehicles in the target lane, and after vector decomposition, obtain the spacing vector decomposition result of the cutting-in vehicle and the following vehicle in the driving direction.

[0078] In this embodiment, the vehicle trajectory data is first collected by using an in-vehicle OBD (On-Board Diagnostic) device. Under the constraint of the lane geometric dimensions, a lane coordinate system is constructed, as Figure 3 shown. The driving direction is defined as the x-axis direction, the speed component in the x-axis direction is defined as the driving speed, the speed component in the y-axis direction is defined as the cutting-in speed, and the displacement vector of the leading vehicle in the defined time period t + Δt speed vector acceleration vector displacement vector of the cutting-in vehicle speed vector acceleration vector displacement vector of the following vehicle 1 speed vector acceleration vector displacement vector of the first-level following vehicle 2 speed vector acceleration vector

[0079] Using the method of vector decomposition, project the vector onto the coordinate axes to obtain the projection of the cutting-in vehicle trajectory speed vector in the coordinate axis direction. Define the speed in the tangent direction (i.e., the x-axis direction) as the speed in the normal direction (i.e., the y-axis direction) as The instantaneous component magnitudes of the cutting-in vehicle trajectory tangent direction speed vector on the x and y axes are obtained as:

[0080]

[0081] Among them, θ 切 is defined as the acute angle formed by the tangent direction of the instantaneous trajectory of the cutting-in vehicle and the direction of the lane center line.

[0082] Similarly, the decomposition components of the velocity vectors of the leading vehicle, following vehicle 1, following vehicle 2, and following vehicle i in the convoy on the x and y axes are obtained.

[0083] Velocity of the leading vehicle:

[0084]

[0085] Velocity of following vehicle 1:

[0086]

[0087] Velocity of following vehicle 2:

[0088]

[0089] Velocity of following vehicle i:

[0090]

[0091] Further analyze the relative position relationship between the cutting-in vehicle and the leading vehicle and following vehicle 1. Using the method of vector decomposition, project the displacement vector onto the coordinate axes to obtain the projection of the cutting-in vehicle's trajectory displacement vector in the coordinate axis directions. Define the displacement vector in the tangent direction as The displacement in the normal direction is The magnitudes of the instantaneous components of the cutting-in vehicle's trajectory tangent direction displacement vector on the x and y axes are respectively:

[0092]

[0093] The vector direction is from the cutting-in vehicle to the convoy vehicle direction, which is defined as the acute angle between the convoy vehicle's driving direction and the distance vector, and is the acute angle between the cutting-in vehicle's driving direction and the distance vector.

[0094] To ensure driving safety, the magnitude of the component in the x-axis direction should maintain the minimum safety threshold to avoid collision between the cutting-in vehicle and following vehicle 1, that is, the magnitude of the component in the x-axis direction x 切x satisfies:

[0095]

[0096] Among them, is the speed of the first following vehicle, is the acceleration of the first following vehicle.

[0097] As Figure 3 shown, for the spacing between the cutting-in vehicle and the following vehicle 1, that is, the spacing between the first vehicles in the queue of vehicles, the spacing vector The parameter that changes with time is This velocity vector is composed of the velocity vector of the following vehicle 1 in the x-axis direction of the driving direction in the queue and the velocity vector of the cutting-in vehicle in the y-axis direction in the x-axis direction, that is:

[0098]

[0099] In this embodiment, the headway h is defined in combination with the concept of headway s , and the headway h s is a scalar, which is defined by the projection length of the body length of the cutting-in vehicle in the x-axis direction of the target lane and the component length of the spacing vector in the x-axis direction, that is:

[0100]

[0101] Step S03. In the simulation analysis environment, when the cutting-in vehicle starts to enter the target lane, according to the decomposition results of the cutting-in vehicle velocity vector, the spacing vector, and the velocity characteristics of the following vehicles, estimate the state changes between the cutting-in vehicle and each following vehicle.

[0102] In this embodiment, specifically according to the cutting-in vehicle velocity vector, the decomposition results of the spacing vector, and the velocity vector of the following vehicle 1, based on the classical full speed difference following model, use the acceleration integral equation to estimate the velocity change and position change of the cutting-in vehicle and the following vehicle 1 in the tangential direction, obtain the velocity difference and position difference between the two vehicles in the x-axis direction, and then according to the vehicle speed and acceleration characteristics of the following vehicle 1, use the following model to estimate the vehicle speed and acceleration changes of the following vehicle 2.

[0103] The above classical full speed difference model is specifically:

[0104]

[0105] Among them, is the acceleration of the nth following vehicle, is the velocity of the nth following vehicle, Δx n (t) is the displacement change amount of the nth following vehicle, a is the sensitivity coefficient, λ is the velocity difference weight coefficient, and V(·) is the optimized velocity function.

[0106] Furthermore, for the speed and position changes of the cutting-in vehicle and the following vehicle 1 in the normal direction, the trajectory data fitting model can be used for estimation and prediction. After obtaining the speed and position change components of the following vehicle 1 and the cutting-in vehicle in the x-axis and y-axis directions, the vehicle trajectory is reconstructed using the vector reconstruction method to obtain the estimated value of the vehicle trajectory at the next moment. The trajectory curve can also be fitted using the vehicle trajectory data to predict the change in the direction angle.

[0107] Step S04. In the simulation analysis environment, calculate the interference factor and the attenuation factor of the vehicle cutting-in effect in the following vehicle fleet composed of all following vehicles. The interference factor is defined based on the state of the following vehicle and the interference state, and the interference state includes the distance and speed difference between the following vehicle and the cutting-in vehicle. The attenuation factor is defined based on the speed change characteristics of the following vehicle.

[0108] In this embodiment, the following state 1 is first defined using parameters such as the distance and speed difference between the following vehicle 1 and the leading vehicle, and the interference state is defined using parameters such as the distance and speed difference between the interfering vehicle and the following vehicle. Under the interference state, the proportion of the displacement of the following vehicle 1 in its total displacement is defined as P1, and under the following state, the proportion of the displacement of the following vehicle 1 in its total displacement is defined as (1 - P1). The interference parameter of the following vehicle 1 is defined as:

[0109]

[0110] Similarly, using the classical following model and the trajectory data fitting method, the displacement change of the following vehicle 2 in the x-axis direction and the lateral displacement of the following vehicle 2 in the y-axis direction caused by the lateral displacement of the following vehicle 1 in the y-axis direction are obtained. At the same time, using the method of displacement vector reconstruction, the trajectory vector of the following vehicle 2 is estimated. The proportion of the displacement of the following vehicle 2 under the longitudinal guidance of the following vehicle 1 is defined as P2, and the proportion of the displacement of the following vehicle 2 under the lateral influence of the following vehicle 1 is defined as (1 - P2). The interference parameter of the following vehicle 2 is defined as:

[0111]

[0112] Similarly, the interference parameter of the following vehicle i in the following vehicle fleet is obtained as:

[0113]

[0114] Using the vehicle speed and position to update the corresponding time to define the attenuation factor κ of the lateral cutting-in on the following vehicle fleet j , and this attenuation factor is specifically defined as using the time period from the moment when the following vehicle 1 in the following vehicle fleet decelerates to the moment when it accelerates to the target vehicle speed as the denominator, and the last affected vehicle j in the fleet from the moment when it decelerates to the moment when it accelerates to the target vehicle speed The time period is the numerator, and the specific calculation formula is:

[0115]

[0116] Among them, the factor κ j The value range is [0, 1]. When the value is 0, that is, when the first vehicle in the vehicle platoon (the following vehicle 1) is in the process of being cut in by the cutting-in vehicle, the cutting-in effect does not decay; when the value starts to appear as 1, that is, in the following vehicle platoon, the effect brought by the cutting-in vehicle has completely decayed, that is, the effect does not affect the following vehicle j in the following vehicle platoon. The serial number j corresponds to the vehicle serial number when the cutting-in effect of the cutting-in vehicle ends. The j value and the moment t can be calibrated using the following vehicle speed data.

[0117] Step S05. According to the interference factor and the attenuation factor, obtain the influence degree of the lateral interference on the displacement and speed of the following vehicle during the process of the cutting-in vehicle driving into the following vehicle platoon and the correlation characteristics between the front and rear vehicles in the following vehicle platoon.

[0118] Regarding the analysis of the interference factor parameters, considering that when the cutting-in vehicle drives into the following vehicle platoon, due to the cutting-in vehicle entering the target lane, it generates lateral interference to the following vehicles in the target lane. The trajectory of the following vehicle 1 will be composed of the following displacement and the lateral offset displacement. Similarly, according to the fitting of the following vehicle model and the trajectory data, the trajectory of the subsequent vehicle of the following vehicle 1, that is, the following vehicle 2, is composed of the following displacement and the lateral offset displacement. Therefore, the interference factor parameters are used to define the influence effect of the cutting-in vehicle on the displacement of the following vehicles in the following vehicle platoon. In this embodiment, (α1, α2,..., α i ) is used to analyze the influence effect of the cutting-in vehicle on the moving displacement of the following vehicle i in the following vehicle platoon. The analysis result of the interference parameter characteristics obtained in the specific application embodiment is as Figure 4 shown, where the abscissa corresponds to the following vehicle i, and the ordinate corresponds to the interference parameter characteristic α i .

[0119] Regarding the analysis of the attenuation factor parameters, considering that when the cutting-in vehicle drives into the following vehicle platoon, due to the cutting-in vehicle entering the target lane, it generates lateral interference to the following vehicles in the target lane. The vehicle speed of the following vehicle 1 will be composed of the following vehicle speed and the lateral offset vehicle speed. Similarly, according to the fitting of the following vehicle model and the trajectory data, the speed of the subsequent vehicle of the following vehicle 1, that is, the following vehicle 2, is composed of the following speed and the lateral offset speed. Therefore, the attenuation factor parameters are used to define the influence effect of the cutting-in vehicle on the vehicle speed of the following vehicles in the following vehicle platoon. In this embodiment, the attenuation factor κ j is used to analyze the influence effect of the cutting-in vehicle on the vehicle speed of the following vehicle. In the specific application embodiment, the change characteristics of the attenuation factor obtained are as Figure 5As shown, where the abscissa corresponds to the vehicle number when the cut-in vehicle produces the end of the attenuation of the cut-in effect for j, and the ordinate corresponds to the attenuation factor κ j .

[0120] In this embodiment, the correlation index λ(L) is specifically used to describe the correlation characteristics between the front and rear following vehicles in the target lane, and then the change law curve of this characteristic under normal driving and the presence of interference is obtained. The calculation formula of the correlation index λ(L) is:

[0121]

[0122] where L is the distance between two vehicles traveling in the same lane in the traveling direction, L min , L max are respectively the minimum distance and the maximum distance between two vehicles traveling in the same lane in the traveling direction, k is the weight coefficient, and L -1 is the reciprocal of the distance.

[0123] In the specific application embodiment, the change characteristics of the distance between the following vehicle 1 and the following vehicle 2 in the target lane are obtained according to the above steps, and the change law of the vehicle distance under no interference and the presence of interference in the target lane is quantified through the correlation factor λ(L). The obtained results are as Figure 6 described, where Figure 6 (a) corresponds to the correlation curve characteristic under no interference influence, Figure 6 (b) in is the correlation curve characteristic under the influence of interference. When the distance between vehicles exceeds the threshold interval, there is no interaction between the front and rear vehicles, that is, when the distance between the two vehicles is greater than L max , there is no correlation between the vehicles, and the front vehicle does not attract the rear vehicle. When the distance between the two vehicles is less than L min , to ensure safety, the front vehicle repels the rear vehicle. Therefore, when the distance between the two vehicles enters a certain interval, the rear vehicle will maintain following the front vehicle, and attraction and repulsion will occur repeatedly, and the distance between the two vehicles will oscillate.

[0124] The cut-in projection of the vehicle in the target lane is as Figure 7 shown, where Figure 7 (a) corresponds to the initial stage of cut-in. When the following vehicle 2 approaches the following vehicle 1, that is, when the interval between the two vehicles reaches the threshold interval, there is no lateral cut-in interference at this time. To ensure following safety, the speed of the following vehicle 2 will change slowly, and outside the threshold interval of the interval between the two vehicles, the following vehicle 2 will travel at the maximum safe speed designed for the road. The middle and late stages of cut-in are as Figure 7 (b) shown. When the following vehicle 2 approaches the following vehicle 1 and the interval between the two vehicles enters the threshold interval, if there is a lateral cut-in interference from a vehicle in the adjacent lane at this time, the following vehicle 1 will significantly decelerate to maintain following safety, and may even decelerate to 0. Outside the threshold of the interval between the two vehicles, the following vehicle 2 will travel according to the maximum safe speed designed for the road.

[0125] Step S06. Estimate the remaining area of the lane based on the spacing vectors of the cutting-in vehicle, the following vehicle, and the leading vehicle.

[0126] Considering that the cutting-in vehicle in the target lane reduces the available driving space of the following vehicle under the action of lateral interference, in this embodiment, the influence of the laterally cutting-in vehicle on the following vehicle is analyzed by using the remaining driving area of the following vehicle. As Figure 8 shown, in the simulation analysis environment, the influence of lateral cutting-in on the spacing change can be analyzed. When the lateral cutting-in starts to enter the target lane, the vehicle spacing between the leading vehicle and the following vehicle 1, and the remaining passing area of the lane of the following vehicle 1 will be squeezed. The lane passing area of the following vehicle 1 is defined as the product of the integral of the vehicle spacing change speed V L (t) and the vehicle width w, that is:

[0127] w·∫V L (t)dt (16)

[0128] In this embodiment, a rectangular area estimation method is specifically used to estimate the cutting-in influence area: the cutting-in influence area is defined as a rectangle formed by the projection of the body length of the cutting-in vehicle in the x-axis direction and the projection of the vehicle width. The cutting-in influence area is as shown in the formula:

[0129] (L 切x -∫v(t)cosθdt)·(w 车道y -∫v(t)sinθdt) (17)

[0130] where L 切x is the spacing between the cutting-in vehicle and the following vehicle in the x-axis direction, w 车道y is the lane width of the target lane, v(t) is the speed function of the cutting-in vehicle, and θ is the angle between the vehicle cutting-in direction and the lane center line direction.

[0131] When the drivable area of the lane is squeezed, for the following vehicle, the area of the drivable area of the lane will change. Considering the velocity projections of the cutting-in vehicle in the x and y directions during the cutting-in process, the estimation formula for the remaining drivable area of the lane is specifically as follows:

[0132] A=w·∫V L (t)dt-(L 切x -∫v(t)cosθdt)·(w 车道y -∫v(t)sinθdt) (18)

[0133] Through the above steps, this embodiment can analyze the change in the remaining drivable lane area in the target lane caused by a lateral cut-in, and then obtain the change law of the remaining drivable lane area in the target lane due to the lateral cut-in. In a specific application embodiment, the change characteristics of the remaining lane area of the following vehicle 1 under the influence of the lateral cut-in vehicle are as Figure 8 shown.

[0134] In view of the lateral interference phenomenon caused by a vehicle cutting into a target lane to the following vehicle in the target lane, the present invention uses a vector analysis method to obtain the two-dimensional decomposition of the lateral interference, and obtains the two-dimensional decomposition components of the cut-in vehicle speed during the cut-in process and the decomposition result of the spacing vector between the cut-in vehicle and the following vehicle in the target lane. The method of analyzing following characteristics mainly relying on a single-dimensional parameter of vehicle spacing is extended to two dimensions. Furthermore, the area of the remaining drivable area of the lane is used to quantify the impact of the lateral interference cut-in on the following vehicle and the vehicle platoon in the target lane, which can effectively analyze the changes in the spacing and vehicle speed of the following vehicle in the tangential and normal directions under the lateral interference, improve the accuracy and effectiveness of the estimation, and solve the problem of low estimation accuracy in traditional microscopic traffic flow simulation schemes due to only considering the spacing in the forward direction of the vehicle while ignoring the lateral spacing in actual vehicle driving.

[0135] The above is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for estimating the state change of a following vehicle considering lateral interference under two-lane driving, characterized in that the steps Including: Step S01. Construct a simulation analysis environment including a leading vehicle on the target lane, a cutting-in vehicle on the adjacent lane, and a following vehicle on the target lane, for simulating the changes in the speed characteristics of the following vehicle and the vehicle platoon when the cutting-in vehicle cuts into the target lane and generates lateral interference under the condition of two-lane driving; Step S02. Obtain the vehicle trajectory data and lane geometric dimension data of the cutting-in vehicle and input them into the simulation analysis environment, extract the instantaneous velocity vector of the cutting-in vehicle when it cuts into the target lane and perform vector decomposition to obtain the decomposition result of the cutting-in vehicle velocity vector, and extract the instantaneous displacement vector of the cutting-in vehicle when it cuts into the lane, the spacing vectors between the cutting-in vehicle and the front and rear vehicles in the target lane, and after vector decomposition, obtain the decomposition result of the spacing vector between the cutting-in vehicle and the following vehicle in the driving direction; Step S03. In the simulation analysis environment, when the cutting-in vehicle starts to enter the target lane, estimate the state changes between the cutting-in vehicle and each following vehicle according to the decomposition result of the cutting-in vehicle velocity vector, the decomposition result of the spacing vector, and the speed characteristics of the following vehicle; Step S04. In the simulation analysis environment, calculate the interference factor and the attenuation factor of the vehicle cutting-in effect in the following vehicle platoon composed of all following vehicles. The interference factor is obtained according to the state of the following vehicle and the interference state definition, and the interference state includes the spacing and speed difference between the following vehicle and the cutting-in vehicle. The attenuation factor is obtained according to the speed change characteristics of the following vehicle; Step S05. According to the interference factor and the attenuation factor, obtain the influence degree of the lateral interference on the displacement and speed of the following vehicle during the process of the cutting-in vehicle entering the following vehicle platoon and the correlation characteristics between the front and rear vehicles in the following vehicle platoon; Step S06. Estimate the remaining area of the lane according to the spacing vectors of the cutting-in vehicle, the following vehicle, and the leading vehicle; The said Step S03 includes: According to the cutting-in vehicle velocity vector, the decomposition result of the spacing vector, and the velocity vector of the first following vehicle, use the full speed difference model to estimate the velocity change and position change of the cutting-in vehicle and the first following vehicle in the tangential direction, and obtain the speed difference and spacing change between the cutting-in vehicle and the first following vehicle. The full speed difference model is: wherein, is the acceleration of the nth following vehicle, is the speed of the nth following vehicle, Δx n (t) is the displacement change of the nth following vehicle, a is the sensitivity coefficient, λ is the speed difference weight coefficient, and V(·) is the optimal speed function; Use the trajectory data fitting model to estimate and predict the velocity and position changes of the cutting-in vehicle and the first following vehicle in the normal direction, obtain the velocity and position change components of the first following vehicle and the cutting-in vehicle in the x-axis and y-axis directions, and then obtain the estimated value of the vehicle trajectory at the next moment, and use the vehicle trajectory data to fit the trajectory curve to predict the change of the direction angle.

2. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to claim 1, characterized in that, In the said Step S01, in the constructed simulation analysis environment, by analyzing the lateral interference on the first following vehicle in the target lane when the cutting-in vehicle cuts into the target lane according to the vehicle trajectory data, use the following model to evolve the following characteristics of the first following vehicle and the second following vehicle and the change of the vehicle platoon speed characteristics. The first following vehicle is the nearest following vehicle after the cutting-in vehicle cuts into the target lane, and the second following vehicle is the second nearest following vehicle after the cutting-in vehicle cuts into the target lane.

3. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to claim 2, wherein When performing vector decomposition on the instantaneous velocity vector of the cutting-in vehicle in the cutting-in lane in step S02, specifically, vector decomposition is performed on the instantaneous velocity vector of the cutting-in vehicle in the cutting-in lane to obtain the tangential direction velocity component and the normal direction velocity component of the vehicle trajectory in a specified period. The steps include: Construct a lane coordinate system under the constraint of lane geometric dimensions using vehicle trajectory data, define the driving direction as the x-axis direction, define the velocity component in the x-axis direction as the driving speed, and define the velocity component in the y-axis direction as the cutting-in speed. Define the state vectors of the leading vehicle, cutting-in vehicle, first following vehicle, and second following vehicle within a specified period. The state vectors include displacement vectors, velocity vectors, and acceleration vectors. Use the method of vector decomposition to project the state vectors onto the coordinate axes to obtain the projections of the cutting-in vehicle trajectory velocity vector onto the coordinate axis directions, and further obtain the instantaneous component magnitudes of the cutting-in vehicle trajectory tangential direction velocity vector on the x and y axes as: Among them, is the velocity in the tangential direction, is the velocity in the normal direction, and θ 切 is the acute angle formed by the tangential direction of the instantaneous trajectory of the cutting-in vehicle and the direction of the lane center line; And obtain the decomposition components of the velocity vectors of the leading vehicle, first following vehicle, second following vehicle, and each following vehicle within the vehicle platoon on the x and y axes.

4. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to claim 3, characterized in that In the aforementioned step S02, extracting the instantaneous displacement vector of the cutting-in vehicle when cutting into the lane and the spacing vectors between the cutting-in vehicle and the vehicles in front and behind in the target lane includes: Extract the instantaneous displacement vector of the cutting-in vehicle when cutting into the lane. Use the method of vector decomposition to project the instantaneous displacement vector onto the coordinate axes to obtain the projection of the cutting-in vehicle trajectory displacement vector onto the coordinate axis directions, and obtain the instantaneous component magnitudes of the cutting-in vehicle trajectory tangential direction displacement vector on the x and y axes as: and Among them, is the displacement vector in the tangent direction, is the displacement vector in the normal direction, and the vector direction points from the cutting-in vehicle to the queue vehicle direction, is the acute angle between the vehicle driving direction of the cutting-in vehicle and the distance vector, and the component size x in the x-axis direction 切x satisfies: That is, the component magnitude x in the x-axis direction 切x Maintain the minimum safety threshold to avoid collision between the cutting-in vehicle and the first following vehicle, where is the speed of the first following vehicle, is the acceleration of the first following vehicle; According to the velocity vector of the cutting-in vehicle in the x-axis direction The velocity vector of the cutting-in vehicle in the y-axis direction And the velocity vector of the first following vehicle in the x-axis direction The velocity vector of the first following vehicle in the y-axis direction The spacing vector is obtained according to the following formula The parameter varying with time and the projected length in the x-axis direction of the target lane and the spacing vector according to the body length of the cutting-in vehicle Calculate the headway h according to the component length in the x-axis direction by the following formula s : Among them, is the displacement vector of the cutting-in vehicle in the x-axis direction, and θ 切 is the acute angle formed by the tangent direction of the instantaneous trajectory of the cutting-in vehicle and the direction of the lane center line.

5. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to any one of claims 1 to 4, characterized in that Calculating the interference factor in step S04 includes: Define the state of the first following vehicle using the distance and speed difference between the first following vehicle and the leading vehicle, and define the interference state using the distance and speed difference between the interfering vehicle and the following vehicle. Under the interference state, the proportion of the displacement of the first following vehicle in the total displacement is defined as P1, and under the following state, the proportion of the displacement of the first following vehicle in the total displacement is defined as (1 - P1). Define the interference parameter α1 of the first following vehicle as: Using the classical following model and the trajectory data fitting method, obtain the displacement change of the second following vehicle in the x-axis direction, and the lateral displacement of the second following vehicle in the y-axis direction caused by the lateral displacement of the first following vehicle in the y-axis direction, and estimate the trajectory vector of the second following vehicle. Define the displacement proportion of the second following vehicle under the longitudinal guidance of the first following vehicle as P2, and the displacement proportion of the second following vehicle under the lateral influence of the first following vehicle as (1 - P2). Define the interference parameter α2 of the second following vehicle as: Then obtain the interference parameter of the i-th following vehicle in the following vehicle platoon as: In step S05, use α1, α2,..., α i Analyze the influence effect of the cutting-in vehicle on the moving displacement of the following vehicle i in the following vehicle platoon.

6. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to any one of claims 1 to 4, characterized in that Calculating the attenuation factor in step S04 includes: Update the attenuation factor κ corresponding to the lateral cut-in impact on the following vehicle platoon by using the vehicle speed and position at the corresponding moment j , that is, the attenuation factor κ j is defined as follows: taking the time period from the deceleration moment to the moment when the first following vehicle in the following vehicle platoon accelerates to the target vehicle speed as the denominator, and the time period from the deceleration moment to the moment when the last affected vehicle j in the platoon accelerates to the target vehicle speed as the numerator. The specific calculation formula is as follows: Among them, factor κ j The value range is [0, 1]. When the value is 0, it means that when the first following vehicle in the vehicle platoon is in the process of being cut in by the cutting-in vehicle, the cutting-in effect has no attenuation; when the value starts to appear as 1, it means that the effect brought by the cutting-in vehicle in the following vehicle platoon has been completely attenuated, that is, the effect does not affect the following vehicle j in the following vehicle platoon, and j corresponds to the vehicle serial number at the end of the attenuation of the cutting-in effect generated by the cutting-in vehicle. In the step S05, the attenuation factor κ is used j Analyze the influence effect of the cutting-in vehicle on the vehicle speed of the following vehicles in the following vehicle platoon 7. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to any one of claims 1 to 4, characterized in that, In step S05, according to the interference factor and attenuation factor, obtain the correlation characteristics between the front and rear vehicles in the following vehicle platoon, including: Use the correlation index λ(L) to describe the correlation characteristics between the front and rear following vehicles in the target lane, and obtain the variation law of the correlation characteristics under normal driving and the presence of interference. The calculation expression of the correlation index λ(L) is: Among them, L is the distance between two vehicles traveling in the same lane in the driving direction, L min and L max are respectively the minimum distance and the maximum distance between two vehicles traveling in the same lane in the driving direction, k is the weight coefficient, and L -1 is the reciprocal of the distance.

8. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to any one of claims 1 to 4, characterized in that, The said step S06 includes: Define the lane passing area of the first following vehicle as the product of the integral of the speed of change of the vehicle-to-vehicle distance V L (t) and the vehicle width w, i.e.: w·∫V L (t)dt Define the cut-in influence area as a rectangle formed by the projection of the length of the cut-in vehicle body in the x-axis direction and the projection of the vehicle width, that is, the calculation expression of the cut-in influence area is: (L 切x -∫v(t)cosθdt)·(w 车道y -∫v(t)sinθdt) Among them, L 切x is the spacing between the cutting-in vehicle and the following vehicle in the x-axis direction, w 车道y is the lane width of the target lane, v(t) is the speed function of the cutting-in vehicle, and θ is the angle between the vehicle cutting-in direction and the lane centerline direction; Considering the velocity projections of the cut-in vehicle in the x and y directions during the cut-in process, estimate the remaining available driving area A of the lane according to the following formula: A = w·∫V L (t)dt - (L 切x -∫ v (t)cosθdt)·(w 车道y -∫v(t)sinθdt).

9. The method for estimating the state change of a following vehicle considering lateral interference under two-lane driving according to any one of claims 1 to 4, characterized in that The said step S06 further includes obtaining the variation law of the remaining area of the target lane during the vehicle cut-in process based on the estimated remaining available driving area of the lane.

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