Method and system for determining mainline continuous entry spacing on a highway under heterogeneous traffic flow

Abstract

The application discloses a kind of expressway main line continuous entry spacing determination method and system under heterogeneous traffic flow, wherein, including the following steps: step S1: based on the traffic flow data analysis vehicle driving behavior, vehicle type is divided into artificial driving vehicle and automatic driving vehicle;Step S2: based on lane changing decision-making process, the lane changing behavior model corresponding to lane changing scene is constructed;Step S3: the length of upstream zone acceleration lane and the distance of midstream zone merging safety sight distance are added, and the spacing of continuous entry is obtained;It can provide methodological guidance for the main line continuous entry spacing determination under the heterogeneous traffic flow that may appear in actual expressway, to guarantee the traffic safety and traffic efficiency under heterogeneous traffic flow.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of highway design, in particular to a method and system for determining the spacing of continuous entrances on the main line of a highway under heterogeneous traffic flow. BACKGROUND

[0002] With the continuous development of autonomous driving technology, in the future, before fully deploying autonomous vehicles, they will coexist with manually driven vehicles for a long time, and the heterogeneous traffic flow composed of autonomous vehicles and manually driven vehicles will replace the single manually driven vehicle flow. The mutual influence between manually driven vehicles and autonomous vehicles poses a challenge to traffic operation to adapt to heterogeneous traffic flow. The continuous entrance section on the main line of the highway is one of the important nodes that affect the traffic operation of the highway. Not only is there a merging and merging, but there are also lane changing, following and pushing behaviors between two entrances. The complex driving behaviors make it more difficult to design the continuous entrance section. The spacing of continuous entrances is a key indicator of the design of continuous entrance sections. There are great differences between autonomous vehicles and manually driven vehicles, and the driving behavior of vehicles on the continuous entrance section under heterogeneous traffic flow will be more complex. Therefore, the reasonable setting of the spacing of continuous entrances is of great significance to improve the traffic safety and efficiency in the entire interchange range.

[0003] At present, in determining the value of the spacing of continuous entrances, the parameter system in the "Highway Route Design Specification" (JTG D20-2017) is based on single manually driven vehicle flow, without considering the influence of autonomous vehicles, and the driving behavior of vehicles on the continuous entrance section is not comprehensive enough. In determining the spacing of continuous entrances, the spacing of continuous entrances is mainly divided into the length of the acceleration lane and the safe merging distance, and more attention is paid to manually driven vehicles, and less attention is paid to heterogeneous traffic flow environment. The mutual influence between vehicles under heterogeneous traffic flow environment is not fully reflected.

[0004] The driving behavior on the continuous entrance section under heterogeneous traffic flow environment is more complex, and the influence of heterogeneous traffic flow on the value of the spacing of continuous entrances on the highway should be further explored to determine the spacing of continuous entrances that can meet the traffic safety and efficiency under heterogeneous traffic flow, improve the safety and road traffic efficiency of vehicles driving on the main line of the continuous entrance section, and have certain practical significance for the construction of future intelligent highways. SUMMARY

[0005] The purpose of the present application is to provide a method and system for determining the spacing of continuous entrances on the main line of a highway under heterogeneous traffic flow, which can provide methodological guidance for determining the spacing of continuous entrances on the main line under heterogeneous traffic flow that may occur in actual highways, to ensure traffic safety and efficiency under heterogeneous traffic flow.

[0006] The application discloses a method for determining the interval of a continuous entrance of a main line of an expressway under a heterogeneous traffic flow, which is characterized by comprising the following steps.

[0007] Step S1: obtaining traffic flow data under a heterogeneous traffic flow environment, analyzing vehicle driving behaviors based on the traffic flow data, and dividing vehicle types into manually driven vehicles and automatically driven vehicles;

[0008] Step S2: dividing a lane-changing scene according to the vehicle type of a lane-changing vehicle and the vehicle type of a rear vehicle of a target lane after lane-changing, determining the lane-changing scene according to the penetration rate of an automatically driven vehicle, analyzing a lane-changing decision process based on the lane-changing scene, dividing the lane-changing decision process into position judgment, gap judgment, initial decision of the lane-changing vehicle, decision of the rear vehicle of the target lane after lane-changing and re-decision of the lane-changing vehicle, and constructing a lane-changing behavior model corresponding to the lane-changing scene based on the lane-changing decision process;

[0009] Step S3: calculating the length of an acceleration section of an upstream acceleration lane based on vehicle acceleration and vehicle merging speed, calculating the length of a gap determination section of the upstream acceleration lane based on gap waiting distance and gap adjustment distance, determining the length of a gradual change section of the upstream acceleration lane based on a preset standard, adding the length of the acceleration section of the upstream acceleration lane, the length of the gap determination section of the upstream acceleration lane and the length of the gradual change section of the upstream acceleration lane to obtain the length of the upstream acceleration lane, calculating the reaction distance of a merging safety sight distance of a middle stream based on vehicle running speed and vehicle reaction time, calculating the decision distance of the merging safety sight distance of the middle stream based on vehicle running speed and vehicle decision time, calculating the lane-changing distance of the merging safety sight distance of the middle stream or the deceleration distance of the merging safety sight distance of the middle stream based on lane-changing decision, and adding the reaction distance of the merging safety sight distance of the middle stream, the decision distance of the merging safety sight distance of the middle stream and the lane-changing distance of the merging safety sight distance of the middle stream or the deceleration distance of the merging safety sight distance of the middle stream to obtain the distance of the merging safety sight distance of the middle stream, and adding the length of the upstream acceleration lane and the distance of the merging safety sight distance of the middle stream to obtain the interval of the continuous entrance.

[0010] Preferably, the method for obtaining the traffic flow data under the heterogeneous traffic flow environment in step S1 comprises the following steps: taking aerial photographs at fixed time intervals by using a drone to collect video data of the continuous entrance road section of the main line of the expressway, extracting trajectory data of each vehicle in the video data of the continuous entrance road section of the main line of the expressway by using trajectory extraction software, setting different lane regions for the video data of the continuous entrance road section of the main line of the expressway, and obtaining the traffic flow data under the heterogeneous traffic flow environment.

[0011] Preferably, the different lane regions for the video data of the continuous entrance road section of the main line of the expressway comprise an inner lane of the main line, an outer lane of the main line, an upstream acceleration lane and a downstream acceleration lane.

[0012] Preferably, the lane-changing scenario in step S2 is divided according to the vehicle type of the lane-changing vehicle and the vehicle type of the vehicle behind the target lane, and the lane-changing scenario includes:

[0013] The first lane-changing scenario: the vehicle type of the lane-changing vehicle and the vehicle type of the vehicle behind the target lane are both autonomous vehicles;

[0014] The second lane-changing scenario: the vehicle type of the lane-changing vehicle is an autonomous vehicle, and the vehicle type of the vehicle behind the target lane is a manually driven vehicle;

[0015] The third lane-changing scenario: the vehicle type of the lane-changing vehicle is a manually driven vehicle, and the vehicle type of the vehicle behind the target lane is an autonomous vehicle;

[0016] The fourth lane-changing scenario: the vehicle type of the lane-changing vehicle and the vehicle type of the vehicle behind the target lane are both manually driven vehicles;

[0017] In step S2, the lane-changing scenario is determined according to the penetration rate of the autonomous vehicle, and the expression of the penetration rate of the autonomous vehicle is:

[0018]

[0019] Wherein, p1 represents the penetration rate of the autonomous vehicle in the lane where the lane-changing vehicle is located before lane changing, and p2 represents the penetration rate of the autonomous vehicle in the lane where the lane-changing vehicle is located after lane changing, represents the traffic volume of the autonomous vehicle in the lane where the lane-changing vehicle is located before lane changing, represents the traffic volume of the autonomous vehicle in the lane where the lane-changing vehicle is located after lane changing, Q1 represents the total traffic volume in the lane where the lane-changing vehicle is located before lane changing, and Q2 represents the total traffic volume in the lane where the lane-changing vehicle is located after lane changing.

[0020] Preferably, the lane-changing decision process analysis in step S2 based on the lane-changing scenario includes: based on the acceptable gap model, the acceptable gap of the manually driven vehicle and the autonomous vehicle is calculated respectively; according to the difference of the interaction degree between the manually driven vehicle and the autonomous vehicle, the lane-changing mode is divided into direct lane-changing, assisted lane-changing and aggressive lane-changing; according to the lane position and traffic environment of the vehicle located in the continuous entry section, the lane-changing intention of the lane-changing vehicle is divided into mandatory lane-changing intention and arbitrary lane-changing intention.

[0021] Preferably, the expression of the acceptable gap model is:

[0022]

[0023] Wherein, G 人 (x) represents the acceptable gap of the manually driven vehicle, G 自 (x) represents the acceptable gap of the autonomous vehicle, and Smax represents the critical acceptable gap required for direct lane changing, S min represents the critical acceptable gap required for aggressive lane changing, x represents the lane position of the lane-changing vehicle on the continuous entry section, x1 represents the start of the mergeable section, x2 represents the start of the transition section, x3 represents the end of the mergeable section, and x4 represents the end of the midstream zone.

[0024] Preferably, the expression of the length of the acceleration section of the upstream zone acceleration lane in step S3 is:

[0025]

[0026] wherein L1 represents the length of the acceleration section of the upstream zone acceleration lane, v represents the vehicle speed, η represents the rate of change of acceleration with respect to the vehicle speed, v b represents the vehicle speed when performing merging, v a represents the vehicle speed at the nose of the upstream zone merging, and ζ represents the acceleration when the vehicle speed is 0.

[0027] The length of the gap determination section of the upstream zone acceleration lane in step S3 is divided into a gap waiting distance and a gap adjustment distance; wherein the expression of the gap waiting distance is:

[0028]

[0029] wherein l wait represents the gap waiting distance, represents the size of the nth gap of the outermost lane of the main line, L car represents the vehicle body length, v b represents the vehicle speed when the vehicle of the acceleration lane performs merging, represents the vehicle speed of the gap preceding vehicle of the nth gap of the outermost lane of the main line;

[0030] wherein the expression of the gap adjustment distance is:

[0031]

[0032] wherein L adjust represents the gap adjustment distance, S TF represents the safety distance that the vehicle of the acceleration lane and the gap preceding vehicle should maintain, L car represents the vehicle body length, represents the vehicle speed of the gap preceding vehicle of the nth gap of the outermost lane of the main line, v b represents the vehicle speed when the vehicle of the acceleration lane performs merging;

[0033] The expression of the length of the gap determination section of the upstream zone acceleration lane is:

[0034] L2 = l wait + adjust ;

[0035] wherein L2 represents the length of the upstream zone acceleration lane gap determining section, l wait represents the gap waiting distance, l adjust represents the gap adjusting distance;

[0036] The expression of the length of the upstream zone acceleration lane in step S3 is:

[0037] L J = L1 + L2 + L3;

[0038] wherein L J represents the length of the upstream zone acceleration lane, L1 represents the length of the upstream zone acceleration lane acceleration section, L2 represents the length of the upstream zone acceleration lane gap determining section, and L3 represents the length of the upstream zone acceleration lane gradual section.

[0039] Preferably, the reaction distance expression of the midstream zone merging safety sight distance in step S3 is:

[0040] L4 = v c t r ;

[0041] wherein L4 represents the reaction distance of the midstream zone merging safety sight distance, v c represents the vehicle operating speed at the start of the outermost lane of the main line in the midstream zone, and t r represents the vehicle reaction time;

[0042] The decision distance expression of the midstream zone merging safety sight distance in step S3 is:

[0043] L5 = v c t d ;

[0044] wherein L5 represents the decision distance of the midstream zone merging safety sight distance, v c represents the vehicle operating speed at the start of the outermost lane of the main line in the midstream zone, and t d represents the vehicle decision time;

[0045] The lane changing distance or deceleration distance expression of the midstream zone merging safety sight distance in step S3 is:

[0046]

[0047] wherein L6 represents the lane changing distance or deceleration distance of the midstream zone merging safety sight distance, S TF represents the safe lane changing distance between the lane changing vehicle and the front vehicle of the target lane, and L carL represents the length of the vehicle body, τ represents the execution time of the vehicle lane changing, v c represents the vehicle operating speed of the vehicle at the start of the outermost lane of the main line in the middle-upstream zone, represents the vehicle operating speed of the gap front vehicle of the first gap in the inner lane after the vehicle passing reaction decision of the outermost lane in the middle-upstream zone, K1 represents the time of gap elimination, and K2 represents the time of brake force rise;

[0048] The distance expression of the merging safety sight distance in the middle-upstream zone in step S3 is:

[0049] L H = L4+L5+L6;

[0050] wherein, L H represents the distance of the merging safety sight distance in the middle-upstream zone, L4 represents the reaction distance of the merging safety sight distance in the middle-upstream zone, L5 represents the decision distance of the merging safety sight distance in the middle-upstream zone, and L6 represents the lane changing distance of the merging safety sight distance in the middle-upstream zone or the deceleration distance of the merging safety sight distance in the middle-upstream zone.

[0051] To achieve the second purpose, the system for determining the distance between the main line continuous entrances on the expressway under the heterogeneous traffic flow designed by the present application is characterized in that it comprises:

[0052] A traffic flow data acquisition module is configured to acquire traffic flow data under a heterogeneous traffic flow environment, analyze vehicle driving behavior based on the traffic flow data, and divide vehicle types into manually driven vehicles and automatically driven vehicles.

[0053] A lane changing behavior model construction module is configured to divide lane changing scenarios according to the vehicle type of the lane changing vehicle and the vehicle type of the vehicle behind the target lane after lane changing, determine the lane changing scenario according to the penetration rate of the automatically driven vehicle, analyze the lane changing decision process based on the lane changing scenario, divide the lane changing decision process into position judgment, gap judgment, lane changing vehicle preliminary decision, vehicle behind the target lane decision, and lane changing vehicle re-decision, and construct a lane changing behavior model corresponding to the lane changing scenario based on the lane changing decision process.

[0054] The spacing calculation model construction module is configured to calculate the length of the acceleration section of the upstream zone acceleration lane based on vehicle acceleration and vehicle merging speed, calculate the length of the gap determination section of the upstream zone acceleration lane based on gap waiting distance and gap adjustment distance, determine the length of the gradual transition section of the upstream zone acceleration lane based on a preset standard, and add the length of the acceleration section of the upstream zone acceleration lane, the length of the gap determination section of the upstream zone acceleration lane, and the length of the gradual transition section of the upstream zone acceleration lane to obtain the length of the upstream zone acceleration lane; calculate the reaction distance of the merging safety sight distance of the middle zone based on vehicle operating speed and vehicle reaction time, calculate the decision distance of the merging safety sight distance of the middle zone based on vehicle operating speed and vehicle decision time, calculate the lane changing distance of the merging safety sight distance of the middle zone or the deceleration distance of the merging safety sight distance of the middle zone based on lane changing decision, and add the reaction distance of the merging safety sight distance of the middle zone, the decision distance of the merging safety sight distance of the middle zone, and the lane changing distance of the merging safety sight distance of the middle zone or the deceleration distance of the merging safety sight distance of the middle zone to obtain the distance of the merging safety sight distance of the middle zone; and add the length of the upstream zone acceleration lane and the distance of the merging safety sight distance of the middle zone to obtain the spacing of the continuous entrance.

[0055] To achieve the above-mentioned purpose of the third aspect of the present application, a computer program product is designed, which includes computer instructions for enabling a computer to execute the above-mentioned method for determining the spacing of the continuous entrance of the main line of the expressway under the heterogeneous traffic flow.

[0056] The present application has the following beneficial effects:

[0057] (1) The method and system for determining the spacing of the continuous entrance of the main line of the expressway under the heterogeneous traffic flow take into account the differences in vehicle driving behavior under the mixed traffic environment of manually driven vehicles and autonomous vehicles; by distinguishing vehicle types and lane changing scenarios, a lane changing behavior model is constructed that is more in line with the characteristics of actual traffic flow; further, lane changing scenarios are analyzed and determined based on the lane changing decision-making process (position judgment, gap judgment, initial decision of lane changing vehicle, decision of vehicle behind target lane after lane changing, and re-decision of lane changing vehicle) and the penetration rate of autonomous vehicles; compared with traditional spacing determination methods that only consider a single vehicle type, the present application can more accurately capture the interaction and lane changing behavior of different types of vehicles in heterogeneous traffic flow, thereby improving the accuracy and reliability of the determination of the spacing of the continuous entrance of the main line.

[0058] (2) The method and system for determining the continuous entry spacing of the main line of the expressway under the heterogeneous traffic flow, when calculating the continuous entry spacing, consider the safe sight distance of the upstream zone acceleration lane and the midstream zone merging; in the upstream zone, not only the acceleration section length is considered, but also the gap determination section length is calculated through the gap waiting distance and the gap adjustment distance, and the length of the upstream zone acceleration lane gradual change section is determined based on the preset standard, reflecting the actual needs of the vehicle in the process of finding and adjusting to the acceptable gap; in the midstream zone, the reaction distance, the decision distance and the lane changing or deceleration distance are considered to ensure that the merging vehicle has enough safe sight distance; this comprehensive entry spacing calculation, compared with the traditional method of only considering a single factor (such as only considering the acceleration distance), can more comprehensively guarantee the safety of vehicle driving and the efficiency of road traffic. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 A flowchart of a method for determining the continuous entry spacing of the main line of the expressway under the heterogeneous traffic flow is shown.

[0060] Figure 2 A comparative diagram showing the difference between the relative speed and acceleration of the manually driven vehicle and the automatic driving vehicle is shown.

[0061] Figure 3 A comparative diagram showing the difference between the braking processes of the manually driven vehicle and the automatic driving vehicle is shown.

[0062] Figure 4 A scene diagram of each lane changing scene is shown.

[0063] Figure 5 A diagram showing the change of the acceptable gap is shown.

[0064] Figure 6 A decision flowchart of the first lane changing scene is shown.

[0065] Figure 7 A decision flowchart of the second lane changing scene is shown.

[0066] Figure 8 A decision flowchart of the third lane changing scene is shown.

[0067] Figure 9 A decision flowchart of the fourth lane changing scene is shown.

[0068] Figure 10 A road section composition diagram of the continuous entry spacing is shown.

[0069] Figure 11A schematic diagram showing the length division of each segment of the acceleration lane according to an embodiment of the present application.

[0070] Figure 12 A schematic diagram showing the length division of each segment of the acceleration lane according to an embodiment of the present application.

[0071] Figure 13 A schematic diagram showing the gap waiting process according to an embodiment of the present application.

[0072] Figure 14 A schematic diagram showing the gap adjustment process according to an embodiment of the present application.

[0073] Figure 15 A schematic diagram showing the distance division of each distance of the merge safety sight distance according to an embodiment of the present application.

[0074] Figure 16 A schematic diagram showing the scenario of the completion of the lane changing decision stage according to an embodiment of the present application.

[0075] Figure 17 A schematic diagram showing the difference comparison of the deceleration process of the manually driven vehicle and the autonomous vehicle according to an embodiment of the present application.

[0076] Figure 18 A schematic diagram showing the flow of the continuous entry spacing calculation model according to an embodiment of the present application.

[0077] Figure 19 A schematic diagram showing the modules of the expressway mainline continuous entry spacing determination system under heterogeneous traffic flow according to an embodiment of the present application. DETAILED DESCRIPTION

[0078] Exemplary embodiments of the present disclosure will be described below in greater detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0079] Embodiment 1

[0080] As shown in the drawings, the present embodiment provides a method for determining the continuous entry spacing of the expressway mainline under heterogeneous traffic flow, which comprises the following steps: Figure 1

[0081] Step S1: Obtain the traffic flow data under the heterogeneous traffic flow environment, analyze the vehicle driving behavior based on the traffic flow data, and divide the vehicle types into manually driven vehicles and autonomous vehicles.

[0082] ​Step S2: dividing the lane-changing scene according to the vehicle type of the lane-changing vehicle and the vehicle type of the vehicle behind the target lane after lane-changing, determining the lane-changing scene according to the penetration rate of the autonomous vehicle, analyzing the lane-changing decision-making process based on the lane-changing scene, dividing the lane-changing decision-making process into position judgment, gap judgment, lane-changing vehicle initial decision, vehicle behind the target lane decision, and lane-changing vehicle re-decision, and constructing a lane-changing behavior model corresponding to the lane-changing scene based on the lane-changing decision-making process;

[0083] Step S3: calculating the length of the acceleration section of the upstream zone acceleration lane based on the vehicle acceleration and the vehicle merging speed, calculating the length of the gap determination section of the upstream zone acceleration lane based on the gap waiting distance and the gap adjustment distance, determining the length of the gradual transition section of the upstream zone acceleration lane based on a preset standard, adding the length of the acceleration section of the upstream zone acceleration lane, the length of the gap determination section of the upstream zone acceleration lane, and the length of the gradual transition section of the upstream zone acceleration lane to obtain the length of the upstream zone acceleration lane, calculating the reaction distance of the merging safety sight distance of the middle zone based on the vehicle running speed and the vehicle reaction time, calculating the decision distance of the merging safety sight distance of the middle zone based on the vehicle running speed and the vehicle decision time, calculating the lane-changing distance of the merging safety sight distance of the middle zone or the deceleration distance of the merging safety sight distance of the middle zone based on the lane-changing decision, and adding the reaction distance of the merging safety sight distance of the middle zone, the decision distance of the merging safety sight distance of the middle zone, and the lane-changing distance of the merging safety sight distance of the middle zone or the deceleration distance of the merging safety sight distance of the middle zone to obtain the distance of the merging safety sight distance of the middle zone, and adding the length of the upstream zone acceleration lane and the distance of the merging safety sight distance of the middle zone to obtain the spacing of the continuous entrance.

[0084] Based on the above embodiment, the method for obtaining traffic flow data in a heterogeneous traffic flow environment in step S1 includes: using a drone to take pictures of the continuous entrance section of the main line of the expressway at intervals of ten minutes, collecting video data of the continuous entrance section of the main line of the expressway, when statistically analyzing the overall traffic flow, the sample size is as shown in formula (1), when statistically analyzing the speed of the 85th percentile, the sample size is as shown in formula (2).

[0085]

[0086]

[0087] In formulas (1) and (2), n represents the minimum sample size, t represents the distribution statistic, t=1.96 at a 95% confidence level, σ represents the overall standard deviation, when the overall standard deviation is unknown, the sample standard deviation S is used instead, S represents the sample standard deviation, U represents a statistical type constant, for example, when the average vehicle speed is 0, the U of the 85th percentile vehicle speed can be 1.04, and E represents the allowed deviation accuracy, for example, the running speed error can be 2-5 km / h, and the E of the vehicle headway can be 1.5 s.

[0088] The origin of the coordinate system of the collected data is set as the intersection of the right lane line of the outermost lane and the vertical line of the upstream zone merging nose end by trajectory extraction software, such as DataFromSky, to take the vehicle forward direction as the x-axis and the direction perpendicular to the vehicle forward direction as the y-axis, extract the trajectory data of each vehicle in the video data of the continuous entry section of the main line of the expressway, set different lane areas for the video data of the continuous entry section of the main line of the expressway, including the inner lane of the main line, the outer lane of the main line, the upstream acceleration lane and the downstream acceleration lane, and obtain the traffic flow data in the heterogeneous traffic flow environment.

[0089] As shown in Figure 2 , the time period when the vehicle in the data is in a stable following state is selected for analysis, and the relative speed and acceleration comparison chart method is used to calibrate the reaction time. The peak and valley of the relative speed of the front and rear vehicles in the comparison chart method and the peak and valley of the acceleration of the immediately following vehicle are a pair of stimulus-response, and the delay between the peak and valley is the reaction time of the following vehicle. Figure 3 As shown in , the process of starting to decelerate and brake of the automatic driving and manual driving vehicles is analyzed. The change range of deceleration of the manual driving vehicle is larger when braking, and the braking process is more urgent. In comparison, the change range of deceleration of the automatic driving vehicle is more moderate when braking. Under the same initial speed, the braking time required by the manual driving vehicle is shorter. The manual driving vehicle and the automatic driving vehicle are analyzed through the differences in reaction time and braking process.

[0090] Based on the above embodiment, the lane changing scene is divided according to the vehicle type of the lane changing vehicle and the vehicle type of the rear vehicle of the lane changing target lane in step S2, as shown in Figure 4 , the lane changing scene includes:

[0091] The first lane changing scene: the vehicle type of the lane changing vehicle and the vehicle type of the rear vehicle of the lane changing target lane are both automatic driving vehicles;

[0092] The second lane changing scene: the vehicle type of the lane changing vehicle is an automatic driving vehicle, and the vehicle type of the rear vehicle of the lane changing target lane is a manual driving vehicle;

[0093] The third lane changing scene: the vehicle type of the lane changing vehicle is a manual driving vehicle, and the vehicle type of the rear vehicle of the lane changing target lane is an automatic driving vehicle;

[0094] The fourth lane changing scene: the vehicle type of the lane changing vehicle and the vehicle type of the rear vehicle of the lane changing target lane are both manual driving vehicles;

[0095] Based on the above embodiment, the lane changing scene is determined according to the penetration rate of the automatic driving vehicle in step S2, and the expression of the penetration rate of the automatic driving vehicle is shown as formula (3).

[0096]

[0097] In formula (3), p1 represents the penetration rate of the autonomous vehicle in the lane where the lane-changing vehicle is located before lane changing, p2 represents the penetration rate of the autonomous vehicle in the lane where the lane-changing vehicle is located after lane changing, represents the traffic volume of the autonomous vehicle in the lane where the lane-changing vehicle is located before lane changing, represents the traffic volume of the autonomous vehicle in the lane where the lane-changing vehicle is located after lane changing, veh / h, Q1 represents the total traffic volume in the lane where the lane-changing vehicle is located before lane changing, and Q2 represents the total traffic volume in the lane where the lane-changing vehicle is located after lane changing, veh / h.

[0098] Based on the above embodiment, the lane-changing decision process based on the lane-changing scenario in step S2 includes: based on the acceptable gap model, the acceptable gaps of the human-driven vehicle and the autonomous vehicle are calculated respectively; according to the difference in the interaction degree between the human-driven vehicle and the autonomous vehicle, the lane-changing mode is divided into direct lane-changing, assisted lane-changing and aggressive lane-changing; and according to the lane position and traffic environment of the vehicle located in the continuous entry section, the lane-changing intention of the lane-changing vehicle is divided into mandatory lane-changing intention and arbitrary lane-changing intention.

[0099] In this embodiment, the part of the merging section of the acceleration lane except the gradual section is divided into three sections, so the acceptable gap of the human-driven vehicle changes twice, and the acceptable gap of the autonomous vehicle changes linearly. At the same time, the acceptable gap of the vehicle in the middle reaches does not change with the change of the position. The change trend of the acceptable gap is as shown in Figure 5 .

[0100] The expression of the acceptable gap model is shown in formula (4) and (5).

[0101]

[0102] In formula (4) and (5), G 人 (x) represents the acceptable gap of the human-driven vehicle, m, G 自 (x) represents the acceptable gap of the autonomous vehicle, m, S max represents the critical acceptable gap required for direct lane-changing, m, S min represents the critical acceptable gap required for aggressive lane-changing, m, x represents the lane position of the lane-changing vehicle in the continuous entry section, m, x1 represents the start point of the merging section, m, x2 represents the start point of the gradual section, m, x3 represents the end point of the merging section, m, and x4 represents the end point of the middle reaches, m.

[0103] According to the vehicle interaction process, the lane-changing decisions in the four lane-changing scenarios are analyzed respectively.

[0104] In the first lane-changing scenario, the vehicle types of both the lane-changing vehicle and the vehicle following in the target lane after lane change are autonomous vehicles. The lane-changing decision-making process of the lane-changing vehicle is as follows Figure 6 shown; in the first lane-changing scenario, according to the different decisions of the lane-changing vehicle and the vehicle following in the target lane at each stage, there are three behaviors in total: direct lane change, assisted lane change, and aggressive lane change;

[0105] When the vehicle is at x1 ≤ x < x2, if the gap in the target lane satisfies G > S max , the lane-changing vehicle performs a direct lane change; if the gap in the target lane satisfies S min ≤ G < S max , the lane change will have an impact on the vehicle following in the target lane, then the lane-changing vehicle performs an assisted lane change;

[0106] When the vehicle is at x2 ≤ x < x3, since it is at the transition section of the acceleration lane at this time, the urgency of lane change is relatively high. As long as the gap in the target lane satisfies G > S min , the lane-changing vehicle performs an aggressive lane change.

[0107] In the second lane-changing scenario, the vehicle type of the lane-changing vehicle is an autonomous vehicle, and the vehicle type of the vehicle following in the target lane after lane change is a human-driven vehicle. The lane-changing decision-making process of the lane-changing vehicle is as follows Figure 7 shown; in the second lane-changing scenario, according to the different decisions of the lane-changing vehicle and the vehicle following in the target lane at each stage, there are four behaviors in total: direct lane change, assisted lane change, aggressive lane change, and lane change failure;

[0108] When the vehicle is at x1 ≤ x < x2, if the gap in the target lane satisfies G > S max , then the lane-changing vehicle performs a direct lane change; if the gap in the target lane satisfies S min ≤ G < S max , the lane change will have an impact on the vehicle following in the target lane. If the driver of the vehicle following in the target lane is a general type driver or a conservative type driver, then they will decelerate and give way, and the lane-changing vehicle performs an assisted lane change; if the driver of the vehicle following in the target lane is an anxious type driver, then they will reject the lane change request, and the lane-changing vehicle abandons the lane change and waits for the next gap;

[0109] When the vehicle is at x2 ≤ x < x3, since it is at the transition section of the acceleration lane at this time, the urgency of lane change is relatively high. As long as the gap in the target lane satisfies G > S min , the lane-changing vehicle performs an aggressive lane change.

[0110] In the third lane-changing scenario, the vehicle type of the lane-changing vehicle is a human-driven vehicle, and the vehicle type of the vehicle following in the target lane after lane change... The lane-changing decision-making process of the lane-changing vehicle is as follows Figure 8is shown; in the third lane changing scenario, according to the different decisions of the lane changing vehicle and the target lane rear vehicle in each stage, there are four behaviors of direct lane changing, assisted lane changing, aggressive lane changing and lane changing failure;

[0111] When the vehicle is in x1≤x<(2x1+x2) / 3, if the target lane gap satisfies G>G 人 (x), the lane changing vehicle performs direct lane changing. If the target lane gap satisfies S min ≤G<G 人 (x), if the lane changing vehicle driver is an impatient driver, the lane changing vehicle will perform lane changing, and if the target lane rear vehicle is an automatic driving vehicle, the lane changing vehicle will slow down and give way, and the lane changing vehicle performs assisted lane changing; if the lane changing vehicle driver is a general driver or a conservative driver, the lane changing vehicle will give up lane changing and wait for the next gap;

[0112] When the vehicle is in (2x1+x2) / 3≤x<(x1+2x2) / 3, if the target lane gap satisfies G>G 人 (x), the lane changing vehicle performs lane changing, which will affect the target lane rear vehicle, but the target lane rear vehicle is an automatic driving vehicle and chooses to slow down and give way, so the lane changing vehicle performs assisted lane changing. If the target lane gap satisfies S min ≤G<G 人 (x), the acceptable gap satisfies the gap requirement of aggressive lane changing, if the lane changing vehicle driver is an impatient driver or a general driver, the lane changing vehicle will perform lane changing and aggressive lane changing; if the lane changing vehicle driver is a conservative driver, the lane changing vehicle will give up lane changing and wait for the next gap;

[0113] When the vehicle is in (x1+2x2) / 3≤x<x3, if the target lane gap satisfies G>G 人 (x), the acceptable gap satisfies the gap requirement of aggressive lane changing, and since the vehicle is at the end of the acceleration lane at this time, the lane changing urgency is greater, as long as the target lane gap satisfies G>S min , the lane changing vehicle performs aggressive lane changing.

[0114] In the fourth lane changing scenario, the vehicle type of the lane changing vehicle and the vehicle type of the target lane rear vehicle are both manual driving vehicles, and the lane changing decision process of the lane changing vehicle is as shown in Figure 9 ; in the fourth lane changing scenario, according to the different decisions of the lane changing vehicle and the target lane rear vehicle in each stage, there are four behaviors of direct lane changing, assisted lane changing, aggressive lane changing and lane changing failure;

[0115] When the vehicle is in x1≤x<(2x1+x2) / 3, if the target lane gap satisfies G>G 人 (x), the lane changing vehicle performs direct lane changing. If the target lane gap satisfies S min ≤G<G人 (x), if the lane-changing vehicle driver is a normal or conservative type driver, the lane-changing vehicle will give up the lane-changing and wait for the next gap;

[0116] When the vehicle is in (2x1+x2) / 3≤x<(x1+2x2) / 3, if the target lane gap satisfies G>G 人 (x), the lane-changing vehicle performs lane-changing, which will affect the target lane rear vehicle, if the target lane rear vehicle driver is a normal or conservative type driver, the lane-changing vehicle will give way and perform assisted lane-changing, if the target lane rear vehicle driver is an impatient type driver, the lane-changing vehicle will give up the lane-changing. If the target lane gap satisfies S min ≤G<G 人 (x), the acceptable gap satisfies the gap requirement of aggressive lane-changing, if the lane-changing vehicle driver is an impatient or normal type driver, the lane-changing vehicle will perform lane-changing, if the target lane rear vehicle driver is a normal or conservative type driver, the lane-changing vehicle will give way and perform assisted lane-changing, if the target lane rear vehicle driver is an impatient type driver, the lane-changing vehicle will give up the lane-changing; if the lane-changing vehicle driver is a conservative type driver, the lane-changing vehicle will give up the lane-changing and wait for the next gap;

[0117] When the vehicle is in (x1+2x2) / 3≤x<x3, if the target lane gap satisfies G>G 人 (x), the acceptable gap satisfies the gap requirement of aggressive lane-changing, since the vehicle is at the end of the acceleration lane at this time, the lane-changing urgency is greater, as long as the target lane gap satisfies G>S min , the lane-changing vehicle performs aggressive lane-changing.

[0118] As shown in FIG. 1, according to the driving requirements of vehicles on the continuous entry section, the continuous entry spacing is divided into two parts, the length of the upstream zone acceleration lane and the distance of the midstream zone merging safety sight distance. Figure 10 As shown in FIG. 2, the part of the solid line prohibiting merging is called the isolation section, and the part of the dashed line allowing the acceleration lane vehicle to merge into the main line is called the mergable section.

[0119] Figure 11 As shown in FIG. 3, the part of the solid line prohibiting merging is called the isolation section, and the part of the dashed line allowing the acceleration lane vehicle to merge into the main line is called the mergable section.

[0120] As shown in FIG. 4, the part of the solid line prohibiting merging is called the isolation section, and the part of the dashed line allowing the acceleration lane vehicle to merge into the main line is called the mergable section. Figure 12 ​As shown, the acceleration lane isolation section is defined as an acceleration section according to the driving behavior, and the part of the merging section other than the gradual section is called a gap determination section. The acceleration lane length is composed of the acceleration section, the gap determination section, and the gradual section.

[0121] In this embodiment, a calculation model of the acceleration section length is constructed based on a linear change model of acceleration.

[0122] Based on the above embodiment, the expression of the length of the acceleration section of the upstream zone acceleration lane in step S3 is shown as formula (6).

[0123]

[0124] In formula (6), L1 represents the length of the acceleration section of the upstream zone acceleration lane, m, v represents the vehicle operating speed, m / s, and η represents the change rate of acceleration to the vehicle operating speed, m / s 3 , v b represents the vehicle operating speed when performing merging, m / s, v a represents the vehicle operating speed at the merging nose end of the upstream zone, m / s, and ζ represents the acceleration when the vehicle operating speed is 0, m / s 2 .

[0125] As shown in Figure 13 , after the vehicle of the acceleration lane drives through the acceleration section, the gap determination process starts; the first gap of the outermost lane of the main line is judged, if the lane changing condition is met, the gap adjustment is performed to change lanes, if the lane changing condition is not met, the current gap is abandoned, and the second gap of the outermost lane of the main line is waited for, and the lane changing condition is judged again. The distance driven during the waiting for the acceptable gap before the vehicle of the acceleration lane enters the gap adjustment stage is the gap waiting distance.

[0126] As shown in Figure 14 , if the vehicle R of the acceleration lane performs lane changing in the first gap , the gap waiting distance is 0; if the vehicle R performs lane changing in the second gap , the gap waiting distance is the distance driven when the vehicle R and the vehicle 2 are in the same section; if the vehicle R performs lane changing in the nth gap , the gap waiting distance is the distance driven when the vehicle L and the vehicle n are in the same section.

[0127] Based on the above embodiment, the length of the gap determination section of the upstream zone acceleration lane in step S3 is divided into the gap waiting distance and the gap adjustment distance; wherein the expression of the gap waiting distance is shown as formula (7).

[0128]

[0129] In formula (7), l waitrepresents the gap waiting distance, m, represents the size of the nth gap of the outermost lane of the main line, m, L car represents the vehicle body length, m, v b represents the vehicle operating speed when the vehicle in the acceleration lane performs merging, m / s, represents the vehicle operating speed of the gap front vehicle of the nth gap of the outermost lane of the main line, m / s;

[0130] When the vehicle in the acceleration lane passes through the gap waiting stage and determines that a certain gap in the outermost lane of the main line can perform lane changing, the position relationship between the vehicle and the gap needs to be adjusted so that the vehicle and the gap front vehicle satisfy the safe lane changing condition. The distance traveled by the vehicle in this process is the gap adjustment distance.

[0131] In the gap adjustment process, the vehicle R in the acceleration lane should be adjusted to a distance S TF from the nth vehicle in the outermost lane of the main line.

[0132] The gap adjustment distance expression is shown in equation (8).

[0133]

[0134] In equation (8), l adjust represents the gap adjustment distance, m, S TF represents the safe distance that the vehicle in the acceleration lane and the gap front vehicle should maintain, m, L car represents the vehicle body length, m, represents the vehicle operating speed of the gap front vehicle of the nth gap of the outermost lane of the main line, m / s, v b represents the vehicle operating speed when the vehicle in the acceleration lane performs merging, m / s;

[0135] The length expression of the upstream zone acceleration lane gap determination section is shown in equation (9).

[0136]

[0137] In equation (9), L2 represents the length of the upstream zone acceleration lane gap determination section, m, l wait represents the gap waiting distance, m, l adjust represents the gap adjustment distance, m;

[0138] Compared with manually driven vehicles, the steering operation of autonomous vehicles is more accurate and stable. Therefore, autonomous vehicles have good adaptability to the provisions of the “Highway Interchange Design Details” (JTG / TD21-2014) regarding the length of the transition section, and do not need to be modified.

[0139] The length and the gradual rate of the gradual section of the parallel acceleration lane are shown in Table 1 according to the Design Specification for Highway Grade Separation (JTG / TD21-2014).

[0140] Table 1 Length and gradual rate of the gradual section of the parallel acceleration lane

[0141]

[0142] Based on the above embodiment, the expression of the length of the upstream zone acceleration lane in step S3 is shown as formula (10).

[0143] L J = L1+ L2+ L3 (10)

[0144] In formula (10), L J represents the length of the upstream zone acceleration lane, m, L1 represents the length of the acceleration section of the upstream zone acceleration lane, m, L2 represents the length of the gap determination section of the upstream zone acceleration lane, m, and L3 represents the length of the gradual section of the upstream zone acceleration lane, m.

[0145] As shown in Figure 15 , by analyzing the driving behavior of the vehicle in the process of deceleration or in-lane changing in the middle zone, it can be known that the merging safety sight distance is composed of reaction distance, decision distance, lane changing or deceleration distance.

[0146] When there is a vehicle at the downstream entrance, the vehicle at the start position of the outer lane in the middle zone will have a reaction stage, and after the reaction stage ends, the existence of the downstream entrance vehicle is determined. The reaction stage is relatively short, and it can be considered that the vehicle is uniformly driven in this process.

[0147] Based on the above embodiment, the expression of the reaction distance of the merging safety sight distance in the middle zone in step S3 is shown as formula (11).

[0148] L4 = v c t r (11)

[0149] In formula (11), L4 represents the reaction distance of the merging safety sight distance in the middle zone, m, v c represents the running speed of the vehicle at the start position of the outermost lane of the main line in the middle zone, m / s, and t r represents the reaction time of the vehicle, s.

[0150] After the vehicle passes through the reaction process, it needs a certain time to make a decision, that is, to take lane changing measures or deceleration measures subsequently, and this process can be approximately considered as uniform driving of the vehicle.

[0151] Based on the above embodiment, the expression of the decision distance of the merging safety sight distance in the middle zone in step S3 is shown as formula (12).

[0152] L5 = v c t d (12)

[0153] In equation (12), L5 represents the decision distance for safe line-of-sight at the midstream confluence, m, v c This indicates the vehicle speed at the starting point of the outermost lane of the main line in the middle reaches, in m / s and t. d The vehicle decision time is represented by s, and in this embodiment, the decision time for the manually driven vehicle is t. d The value is 1.6s, representing the time t for autonomous vehicles. d The value is 0.5s;

[0154] like Figure 16 As shown, after the decision-making phase, if the first gap in the inner lane... If the gap is acceptable, vehicle M adjusts its position relative to the gap and then performs a lane change; if the first gap in the inner lane... If the lane-changing conditions are not met, vehicle M will decelerate at the downstream merging nose to a passing speed v at the merging nose. d This avoids conflicts with downstream vehicles entering the area. The distance required by a vehicle after the decision-making stage varies depending on the vehicle's decision-making outcome.

[0155] Analysis of drivers' lane-changing patterns reveals that when calculating lane-changing distance, it is unnecessary to consider the waiting gap process; only the distance required for gap adjustment and lane-changing execution needs to be calculated. The expression for lane-changing distance is shown in equation (13).

[0156]

[0157] In equation (13), S TF Indicates the safe lane-changing distance between the vehicle changing lanes and the vehicle in front in the target lane, in meters (m); L car The vehicle length is represented in meters (m); τ represents the lane-changing execution time in seconds (s); v c This indicates the vehicle speed at the starting point of the outermost lane of the main line in the middle reaches, in m / s; This indicates the speed of the vehicle ahead of the vehicle in the first gap of the inner lane after the vehicle in the outermost lane of the middle section has made a reaction decision, in m / s.

[0158] When conditions do not allow for lane changing to the inside lane, the vehicle will continue to travel in the outermost lane and will employ a deceleration strategy, reducing its speed from v. c Down to v d To avoid conflicts with vehicles merging downstream. Different vehicle types have different deceleration processes and require different deceleration distances.

[0159] like Figure 17As shown, the deceleration process of the manually driven vehicle can be divided into a gap elimination phase, a brake force rising phase, and a uniform deceleration phase; since the automatic driving vehicle can stably and accurately control the actuator to generate brake deceleration after making a deceleration decision, the automatic driving vehicle does not have a gap elimination phase.

[0160] The vehicle travel distance expression in the entire deceleration phase is shown in equation (14).

[0161]

[0162] In equation (14), v c represents the vehicle operating speed at the start of the outermost lane of the main line in the middle zone, m / s, K1 represents the time for gap elimination, s, K1 of the manually driven vehicle in the present embodiment is 0.05 s, and K1 of the automatic driving vehicle is 0 s, K2 represents the time for brake force rising, s, K2 of the manually driven vehicle in the present embodiment is 0.3 s, and K2 of the automatic driving vehicle is 0.4 s.

[0163] Based on the above embodiment, the lane changing distance of the merging safety sight distance in the middle zone or the deceleration distance of the merging safety sight distance in the middle zone in step S3 is expressed by equation (14).

[0164]

[0165] In equation (15), L6 represents the lane changing distance of the merging safety sight distance in the middle zone or the deceleration distance of the merging safety sight distance in the middle zone, m, S TF represents the safe lane changing distance between the lane changing vehicle and the front vehicle of the target lane, m, L car represents the vehicle body length, m, τ represents the execution time of vehicle lane changing, s, v c represents the vehicle operating speed at the start of the outermost lane of the main line in the middle zone, m / s, represents the vehicle operating speed of the gap front vehicle of the first gap of the inner lane after the vehicle in the outermost lane of the middle zone makes a reaction decision, m / s, K1 represents the time for gap elimination, s, K1 of the manually driven vehicle in the present embodiment is 0.05 s, and K1 of the automatic driving vehicle is 0 s, K2 represents the time for brake force rising, s, K2 of the manually driven vehicle in the present embodiment is 0.3 s, and K2 of the automatic driving vehicle is 0.4 s;

[0166] Based on the above embodiment, the distance expression of the merging safety sight distance in the middle zone in step S3 is shown in equation (16).

[0167] L H = L4 + L5 + L6 (16)

[0168] In equation (16), L HL4 represents the reaction distance of the midstream zone merging safety sight distance, m, L5 represents the decision distance of the midstream zone merging safety sight distance, m, L6 represents the lane changing distance of the midstream zone merging safety sight distance or the deceleration distance of the midstream zone merging safety sight distance, m.

[0169] According to different decisions, the value of L6 is different, and the value expression is shown in formula (17).

[0170]

[0171] In formula (17), L 6，换道 is the distance required when the vehicle decides to change lanes inward, m; L 6，减速 is the distance required when the vehicle decides to decelerate, m.

[0172] Embodiment 2

[0173] As Figure 18 shown, the embodiment of the application provides a continuous entry spacing calculation model, comprising:

[0174] A solving algorithm for continuous entry spacing calculation is designed based on Monte Carlo simulation by using Python programming, which simulates the randomness of traffic flow by using the Monte Carlo method, and designs the continuous entry spacing by determining the length of the appropriate percentile.

[0175] According to the regulation of the target reliability of the highway pavement structure, the reliability probability is selected as 95%. In the embodiment, the preset length of the upstream zone acceleration lane gap determination section is 500 m, the reliable length under the current preset length is determined, and then iterative calculation is performed until the relative error between the reliable length under the condition that the preset length of the upstream zone acceleration lane gap determination section is 500 m and the preset length of the upstream zone acceleration lane gap determination section is controlled within a certain range λ, at this time, the length of the upstream zone acceleration lane gap determination section is the average value of the reliable length under the condition that the preset length of the upstream zone acceleration lane gap determination section is 500 m and the preset length of the upstream zone acceleration lane gap determination section; according to the related research on the length calculation method of the parallel type acceleration lane of the urban expressway, the value of λ is 0.01.

[0176] In the embodiment, taking the road section from Xiaochang District to Xiaonan District of Beijing-Hong Kong-Macao Expressway (G4) as an example, in order to obtain the basic traffic flow data required for simulation, the traffic volume data during the Spring Festival transportation in the past three years of the road section is counted, and the annual average traffic volume is taken as the simulation times, as shown in Table 2.

[0177] Table 2: Spring Festival traffic volume of Xiaochang District to Xiaonan District from 2019 to 2021

[0178]

[0179] According to Table 2, the total traffic volume of the expressway from 2019 to 2021 is 2.08 million times, and the average of the total traffic volume of three years is about 0.7 million times, so the average of the total traffic volume of three years 0.7 million is taken as the simulation times Y for Monte Carlo simulation calculation in this embodiment.

[0180] In the length calculation process of the acceleration section of the upstream zone acceleration lane, according to the data analysis results of the trajectory extraction software, in this embodiment, the acceleration value when the vehicle operating speed is 0 is ζ=4.4871, and the change rate of acceleration to vehicle operating speed is η=0.2359. According to the proportion of different types of drivers, the probability of anxious type drivers in traffic flow is w1=0.2, the probability of general type drivers is w2=0.6, and the probability of conservative type drivers is w3=0.2. The parameter distribution involved in the continuous entrance spacing calculation model is shown in Table 3.

[0181] Table 3 Random parameter distribution

[0182]

[0183] According to the determined model parameters, the calculation values of different components are obtained. Among them, the calculation result of the acceleration section length is 33.79m; according to the provisions of “Highway Interchange Design Details” (JTG / TD21-2014), when the design vehicle operating speed of the main line is 100km / h, the length of the parallel type acceleration lane transition section is 80m.

[0184] In the remaining spacing components, as the penetration rate of autonomous vehicles increases, the calculation results decrease accordingly, the reduction of gap determination section and lane changing or deceleration distance is relatively uniform, and the reduction of reaction distance and decision distance is relatively uniform in the process of the penetration rate of autonomous vehicles from 0 to 80%, and the reduction is relatively large in the process of the penetration rate of autonomous vehicles from 80% to 100%.

[0185] In this embodiment, the continuous entrance spacing under different penetration rates of autonomous vehicles is calculated and analyzed for the continuous entrance road section with the main line being double lane, the design vehicle operating speed of the main line being 100km / h, and the design vehicle operating speed of the ramp being 40km / h, and the recommended values of the continuous entrance spacing under different penetration rates of autonomous vehicles are shown in Table 4.

[0186] Table 4 Continuous entrance spacing calculation results

[0187]

[0188] As can be seen from Table 4, the greater the penetration rate of autonomous vehicles, the smaller the recommended value of the continuous entrance spacing, which shows that the mixing of autonomous vehicles can effectively meet the needs of various driving behaviors of vehicles on the continuous entrance road section, and save road resources.

[0189] Embodiment 3

[0190] As Figure 19 shown, the embodiment of the application provides a system for determining the distance between continuous entrances on a highway main line under heterogeneous traffic flow, which comprises:

[0191] a traffic flow data acquisition module, configured to acquire traffic flow data under a heterogeneous traffic flow environment, analyze vehicle driving behavior based on the traffic flow data, and divide vehicle types into manually driven vehicles and automatically driven vehicles;

[0192] a lane changing behavior model construction module, configured to divide a lane changing scene according to the vehicle type of a lane changing vehicle and the vehicle type of a vehicle behind a target lane of the lane changing vehicle, analyze a lane changing decision process based on the lane changing scene, divide the lane changing decision process into position judgment, gap judgment, initial decision of the lane changing vehicle, decision of the vehicle behind the target lane, and re-decision of the lane changing vehicle, and construct a lane changing behavior model corresponding to the lane changing scene based on the lane changing decision process;

[0193] a distance calculation model construction module, configured to calculate the length of an acceleration section of an acceleration lane in an upstream area based on vehicle acceleration and vehicle merging speed, calculate the length of a gap determination section of the acceleration lane in the upstream area based on gap waiting distance and gap adjustment distance, calculate the length of a gradual change section of the acceleration lane in the upstream area based on a preset standard, add the length of the acceleration section of the acceleration lane in the upstream area, the length of the gap determination section of the acceleration lane in the upstream area, and the length of the gradual change section of the acceleration lane in the upstream area to obtain the length of the acceleration lane in the upstream area, calculate the reaction distance of a merging safety sight distance in a middle area based on vehicle running speed and vehicle reaction time, calculate the decision distance of the merging safety sight distance in the middle area based on vehicle running speed and vehicle decision time, calculate the lane changing distance of the merging safety sight distance in the middle area or the deceleration distance of the merging safety sight distance in the middle area based on lane changing decision, and add the reaction distance of the merging safety sight distance in the middle area, the decision distance of the merging safety sight distance in the middle area, and the lane changing distance of the merging safety sight distance in the middle area or the deceleration distance of the merging safety sight distance in the middle area to obtain the distance of the merging safety sight distance in the middle area, and add the length of the acceleration lane in the upstream area and the distance of the merging safety sight distance in the middle area to obtain the distance between the continuous entrances.

[0194] Embodiment 3

[0195] The embodiments disclosed herein provide a computer program product, for example, computer program instructions, when executed by a computer, can invoke or provide the method and / or technical solutions according to the present application through the operation of the computer. Those skilled in the art should understand that the form of the computer program instructions in the computer readable medium includes but is not limited to source files, executable files, installation package files, etc. Correspondingly, the way in which the computer program instructions are executed by the computer includes but is not limited to: the computer directly executing the instructions, or the computer executing the corresponding compiled program after compiling the instructions, or the computer reading and executing the instructions, or the computer executing the corresponding installed program after reading and installing the instructions. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described programs and modules can refer to the corresponding process description in the foregoing method embodiments, which will not be described here.

[0196] The algorithms and displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems can be used with programs in accordance with the teachings herein, or it can prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will be apparent from the description above. In addition, the present application is not intended to be limited to any particular programming language. It will be appreciated that there are many programming languages that can be used to implement the teachings herein, and any such programming language can be used in connection with the various aspects of the application. The descriptions above are intended to cover all possible implementations of the application.

[0197] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been described in detail in order to avoid obscuring the understanding of this description.

[0198] Similarly, it is to be understood that the narrative provided above with respect to the exemplary embodiments of the present application sometimes collectively sets forth various features in a single embodiment, drawing, or description of such for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various aspects of the present application. However, the method of this disclosure is not to be interpreted to reflect an intention that the claimed application requires more features than are explicitly recited in each claim. Rather, it is to be understood that the inventive aspects lie in fewer than all of the features of a single disclosed embodiment. Accordingly, the claims as follows are hereby expressly incorporated into this detailed description of the embodiments of the present application, with each claim acting as a separate embodiment of the application.

Claims

1. A method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow, characterized in that, Includes the following steps: Step S1: Obtain traffic flow data under heterogeneous traffic flow environment, analyze vehicle driving behavior based on the traffic flow data, and classify vehicle types into manually driven vehicles and autonomous vehicles. Step S2: Classify the lane-changing scenario based on the vehicle type of the vehicle changing lanes and the vehicle type of the vehicle following in the target lane. The lane-changing scenario includes: First lane-changing scenario: Both the vehicle type of the vehicle changing lanes and the vehicle type of the vehicle following the target lane are autonomous vehicles. Second lane-changing scenario: The vehicle type of the vehicle changing lanes is an autonomous vehicle, and the vehicle type of the vehicle after changing lanes to the target lane is a manually driven vehicle. The third lane-changing scenario: The vehicle type of the vehicle changing lanes is a manually driven vehicle, and the vehicle type of the vehicle after changing lanes to the target lane is an autonomous vehicle. Fourth lane-changing scenario: Both the vehicle type of the vehicle changing lanes and the vehicle type of the vehicle following in the target lane are manually driven vehicles. Lane-changing scenarios are determined based on the penetration rate of autonomous vehicles, whereby the penetration rate of autonomous vehicles is expressed as: Where p1 represents the penetration rate of autonomous vehicles in the lane the lane-changing vehicle was in before the lane change, p $ This indicates the penetration rate of autonomous vehicles in the lane where the lane-changing vehicle is located after the lane change. This indicates the traffic volume of autonomous vehicles in the lane the vehicle was in before changing lanes. Q represents the traffic volume of autonomous vehicles in the lane where the lane-changing vehicle is located after the lane change, and Q1 represents the total traffic volume in the lane where the lane-changing vehicle was located before the lane change. $ This indicates the total traffic volume in the lane where the vehicle that changed lanes is located after the lane change. Based on the lane-changing scenario analysis, the lane-changing decision-making process is divided into position judgment, gap judgment, initial decision of the lane-changing vehicle, decision of the vehicle following the lane-changing target lane, and re-decision of the lane-changing vehicle. Based on the lane-changing decision-making process, a lane-changing behavior model corresponding to the lane-changing scenario is constructed. Step S3: Calculate the length of the acceleration segment of the upstream acceleration lane based on vehicle acceleration and merging speed; calculate the length of the gap determination segment of the upstream acceleration lane based on gap waiting distance and gap adjustment distance; determine the length of the transition segment of the upstream acceleration lane based on a preset standard; add the lengths of the acceleration segment, gap determination segment, and transition segment of the upstream acceleration lane to obtain the length of the upstream acceleration lane; calculate the reaction distance of the midstream merging safety sight distance based on vehicle speed and reaction time. The decision distance for safe merging sight distance in the midstream area is calculated based on vehicle operating speed and vehicle decision time. The lane-changing distance or deceleration distance for safe merging sight distance in the midstream area is calculated based on lane-changing decisions. The reaction distance, decision distance, lane-changing distance, or deceleration distance for safe merging sight distance in the midstream area are added together to obtain the distance of safe merging sight distance in the midstream area. The distance of continuous entrances is obtained by adding the length of the acceleration lane in the upstream area and the distance of safe merging sight distance in the midstream area.

2. The method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow according to claim 1, characterized in that, The method for obtaining traffic flow data under heterogeneous traffic flow environment in step S1 includes: using drones to take aerial photos at fixed time intervals to collect video data of continuous entrance sections of the main line of the highway; extracting trajectory data of each vehicle from the video data of continuous entrance sections of the main line of the highway using trajectory extraction software; setting different lane areas for the video data of continuous entrance sections of the main line of the highway to obtain traffic flow data under heterogeneous traffic flow environment.

3. The method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow according to claim 2, characterized in that, Different lane zones are set for video data of continuous entrance sections of the highway mainline, including: inner lane of the mainline, outer lane of the mainline, upstream acceleration lane and downstream acceleration lane.

4. The method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow according to claim 1, characterized in that, Step S2, based on the lane-changing scenario analysis, includes the following steps: calculating the acceptable gap for both manually driven and autonomous vehicles based on the acceptable gap model; classifying lane-changing methods into direct lane changing, assisted lane changing, and aggressive lane changing based on the difference in the degree of interaction between manually driven and autonomous vehicles; and classifying the lane-changing intention of the vehicle into mandatory lane-changing intention and arbitrary lane-changing intention based on the vehicle's lane position and traffic environment in a continuous entrance road segment.

5. The method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow according to claim 2, characterized in that, The expression for the acceptable gap model is: Among them, G 人 (x) represents the acceptable clearance for manually driven vehicles, G 自 (x) represents the acceptable gap for autonomous vehicles, S ％ax S represents the critical acceptable clearance required for a direct lane change. ％+, The threshold for an aggressive lane change is indicated by x, where x represents the lane position of the changing vehicle in the continuous entry segment, and x1 represents the starting point of the merging segment. $ x3 represents the starting point of the transition segment, and x3 represents the ending point of the segment into which the transition can occur. - This indicates the end point of the middle reaches.

6. The method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow according to claim 1, characterized in that, The expression for the length of the acceleration segment of the upstream acceleration lane in step S3 is: Where L1 represents the length of the acceleration section of the upstream acceleration lane, v represents the vehicle speed, η represents the rate of change of acceleration with respect to vehicle speed, and v2 represents the vehicle speed during merging. a ζ represents the vehicle speed at the confluence nose in the upstream region, and ζ represents the acceleration when the vehicle speed is 0. In step S3, the length of the upstream acceleration lane gap determination segment is divided into gap waiting distance and gap adjustment distance; wherein, the expression for the gap waiting distance is: Among them, l 7a+8 Indicates the waiting distance between intervals. L represents the size of the nth gap in the outermost lane of the main line. a； v1 represents the vehicle's length, and v2 represents the vehicle's speed when vehicles in the acceleration lane merge. This indicates the speed of the vehicle ahead of the nth gap in the outermost lane of the main line; The expression for the gap adjustment distance is as follows: Among them, l a<＝>s8 S indicates the gap adjustment distance. BC L indicates the safe distance that vehicles in the acceleration lane and the vehicle in front should maintain. a； Indicates the length of the vehicle body. v1 represents the vehicle speed ahead of the nth gap in the outermost lane of the main line, and v2 represents the vehicle speed when vehicles in the acceleration lane merge. The length expression for the upstream acceleration lane gap determination segment is: L $ ＝l 7a+8 +l a<＝>s8 ； Among them, L $ l represents the length of the segment used to determine the clearance between acceleration lanes in the upstream region. 7a+8 Indicates the waiting distance, l a<＝>s8 Indicates the gap adjustment distance; The expression for the length of the upstream acceleration lane in step S3 is: L D L1+L $ +L3; Among them, L D L represents the length of the upstream acceleration lane, and L1 represents the length of the acceleration segment of the upstream acceleration lane. $ L1 represents the length of the defined section of the acceleration lane gap in the upstream area, and L2 represents the length of the transition section of the acceleration lane in the upstream area.

7. The method for determining the spacing between continuous entrances to a highway mainline under heterogeneous traffic flow according to claim 1, characterized in that, The reaction distance expression for the midstream confluence safety line of sight in step S3 is: L - =v:t ； ; Among them, L - The reaction distance representing the safe sight distance at the midstream merging point; v: the vehicle speed at the starting point of the outermost lane of the mainline in the midstream area; t ； Indicates vehicle reaction time; The decision distance expression for the safe line-of-sight distance in the midstream merging zone in step S3 is: L E =v : t < ; Among them, L E v represents the decision distance for safe sight distance at the midstream confluence, v represents the vehicle speed at the starting point of the outermost lane of the mainline in the midstream area, and t represents the vehicle speed at the starting point of the outermost lane of the mainline in the midstream area. < Indicates the vehicle's decision-making time; The expression for the lane-changing distance or deceleration distance of the midstream merging safe sight distance in step S3 is as follows: Among them, L F S represents the lane-changing distance or deceleration distance for safe merging sight distance in the midstream area. BC L represents the safe lane-changing distance between the vehicle changing lanes and the vehicle in front in the target lane. a； τ represents the vehicle's length, τ represents the execution time for lane changing, and v represents the vehicle's speed at the starting point of the outermost lane of the mainline in the middle reaches. K1 represents the speed of the vehicle ahead of the vehicle in the first gap in the inner lane after the vehicle in the outermost lane has made a reaction decision. K represents the time it takes for the gap to disappear. $ v represents the time it takes for the braking force to increase. < Indicates the speed at which the confluence nose passes; The distance expression for the safe line-of-sight distance of the midstream merging zone in step S3 is: L J =L - +L E +L F ; Among them, L J L represents the safe line-of-sight distance at the confluence of the middle reaches of the river. - L represents the reaction distance for safe line-of-sight during midstream merging. E L represents the decision distance for safe line-of-sight during the midstream confluence. F This indicates the lane-changing distance or deceleration distance for safe merging visibility in the midstream area.

8. A system for determining the continuous entrance spacing of a highway mainline under heterogeneous traffic flow as described in claims 1-7, characterized in that, include: The traffic flow data acquisition module is used to acquire traffic flow data under heterogeneous traffic flow environments, analyze vehicle driving behavior based on the traffic flow data, and classify vehicle types into manually driven vehicles and autonomous vehicles. The lane-changing behavior model construction module is used to classify lane-changing scenarios based on the vehicle type of the lane-changing vehicle and the vehicle type of the vehicle following the target lane. It determines the lane-changing scenario based on the penetration rate of autonomous vehicles, analyzes the lane-changing decision process based on the lane-changing scenario, and divides the lane-changing decision process into position judgment, gap judgment, initial decision of the lane-changing vehicle, decision of the vehicle following the target lane, and re-decision of the lane-changing vehicle. Based on the lane-changing decision process, it constructs a lane-changing behavior model corresponding to the lane-changing scenario. The spacing calculation model construction module is used to calculate the length of the acceleration segment of the upstream acceleration lane based on vehicle acceleration and vehicle merging speed, calculate the length of the gap determination segment of the upstream acceleration lane based on gap waiting distance and gap adjustment distance, determine the length of the transition segment of the upstream acceleration lane based on preset standards, and add the length of the acceleration segment of the upstream acceleration lane, the length of the gap determination segment of the upstream acceleration lane, and the length of the transition segment of the upstream acceleration lane to obtain the length of the upstream acceleration lane. The reaction distance for safe merging sight distance in the midstream area is calculated based on vehicle speed and reaction time. The decision distance for safe merging sight distance in the midstream area is calculated based on vehicle speed and decision time. The lane-changing distance or deceleration distance for safe merging sight distance in the midstream area is calculated based on lane-changing decisions. The reaction distance, decision distance, lane-changing distance, or deceleration distance for safe merging sight distance in the midstream area are added together to obtain the distance of safe merging sight distance in the midstream area. The distance of continuous entrances is obtained by adding the length of the acceleration lane in the upstream area and the distance of safe merging sight distance in the midstream area.

9. A computer program product, characterized in that, The method includes computer instructions for causing a computer to execute the method for determining the continuous entrance spacing of a highway mainline under heterogeneous traffic flow as described in claim 1.

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