An adaptive control method for highway interchanges

Abstract

The present invention discloses an adaptive control method for highway interchanges, which relates to the field of intelligent transportation technology. It can provide a means based on big data for calculating the safe driving distance of interchange ramp vehicles merging into the main line, provide a basis for controlling the merging of vehicles into the main line, and also provide a method for calculating the merging conditions of vehicles under assisted driving and automatic driving conditions. The present invention includes: when a vehicle merges safely into a target lane on an interchange ramp, the average headway and average speed of the vehicles in the target lane are automatically calculated, and the environmental conditions at this time are recorded; the average speed is discretized, and the discrete speed is corresponded to the average headway under this environmental condition, and the average headway corresponding to the subsequent same environmental condition and discrete speed is used to automatically update the average headway calculated before, and a corresponding table of different discrete speeds and average headway under various environmental conditions is obtained, and the interchange ramp vehicles are adaptively controlled accordingly.

Description

Technical Field

[0001] The present invention relates to the field of intelligent transportation technology, and in particular to an adaptive control method for highway interconnections based on big data. Background Art

[0002] With the continuous development of science and technology and the times, my country's infrastructure construction capacity has been continuously improved, and the technical standards for high-grade highway construction have been continuously improved. The application of new materials and new processes has improved the performance of highway pavement in terms of flatness, deflection, load-bearing capacity, and anti-skid ability to varying degrees; at the same time, with the continuous evolution of vehicle manufacturing technology, vehicle braking performance and tire anti-skid performance have also been improved to varying degrees; in addition, vehicle autonomous braking systems are also being gradually promoted, different levels of assisted driving technologies are being gradually applied, and autonomous driving technology has also achieved rapid development; the above reasons have jointly promoted the shortening of safe driving distances during vehicle driving. It can be foreseen that with the gradual improvement of assisted driving and autonomous driving technologies, the maximum traffic carrying capacity of roads will be effectively improved, and the safe distance of vehicle driving will be further shortened.

[0003] Due to the great changes in today's infrastructure, driving conditions such as vehicle braking, active braking, and assisted driving compared to the past, and the continuous increase in the number of cars has made highway conditions more and more complicated. Therefore, how to analyze and deal with the safe driving distance of highway vehicles and the timing for ramp vehicles to merge into the main line under different environmental conditions has become a problem that needs to be studied. Summary of the invention

[0004] The embodiment of the present invention provides an adaptive control method for a highway interchange, provides a calculation method for the safe driving distance of a highway interchange ramp vehicle merging into a main line, and provides a basis for adaptively controlling the ramp vehicle to safely merge into the main line.

[0005] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0006] S1. When a vehicle is detected merging into a target lane from an interchange ramp, vehicle data of vehicles traveling in the target lane is obtained, wherein the vehicle data includes the number of vehicles, the speed of each vehicle, and the headway between two adjacent vehicles;

[0007] S2, calculating the average headway between adjacent vehicles in the target lane, and calculating the average speed of the vehicles in the target lane;

[0008] S3, discretizing the average vehicle speed, and reducing the discretized average vehicle speed to one of a plurality of different discrete vehicle speeds, wherein the reduced discrete vehicle speed corresponds to the average headway of vehicles in the target lane at this moment;

[0009] S4, iteratively updating the calculated average headway distance, wherein the iterative update is divided according to environmental conditions, and by iteratively updating for different environmental conditions, a corresponding table between discrete vehicle speeds and average headway distances under different environmental conditions is obtained;

[0010] S5. Use the correspondence table of discrete vehicle speeds and average headway distances to adaptively control the intercommunication traffic. The obtained correspondence table can be used as a basis for controlling ramp vehicles to merge into the target lane. In subsequent applications, this correspondence table can be sent to the control end device; it can also be used as statistical data on the headway distances of vehicles merging into the ramp at different speeds under assisted driving or automatic driving conditions, and has a comparative reference value with the current artificially prescribed driving distances. In short, the correspondence table calculated and updated in this embodiment has many subsequent uses, which are not limited by this embodiment.

[0011] Furthermore, before S1, it also includes: S0, real-time monitoring of the outermost lane of the main line merging area of ​​the expressway, and using it as the target lane; it should be noted that for different interchanges, the length of the target lane will vary according to actual conditions; the main line merging area includes the main line area where the ramp of the expressway begins to merge with the main line and ends to merge.

[0012] Specifically, in S1, the headway distance between two adjacent vehicles is obtained, including: obtaining the distance between the headway of a vehicle in the target lane and the headway of a vehicle immediately behind the vehicle; wherein, if the vehicle in the acquired target lane is the last vehicle in the target lane, the distance from the vehicle to the end of the target lane is taken as the headway distance.

[0013] Specifically, in S2, the average headway distance between adjacent vehicles in the target lane is: the average of the distances between the head of each vehicle in the target lane and the head of the vehicle immediately behind the vehicle; the average speed of the vehicle is the average of the speeds of all vehicles in the target lane.

[0014] Specifically, in S3, the discretization processing of the average speed includes: establishing a speed interval with the minimum and maximum speeds of all vehicles in the target lane as the boundary values ​​of the interval, taking a number of discrete speed points (at least 1) in the speed interval, and dividing the speed interval into small speed intervals through the discrete speed points; determining the small speed interval in which the average speed is located, and reducing the average speed to one of the boundary values ​​of the small speed interval. In practical applications, it is not limited whether it is reduced to the boundary value on the left or the boundary value on the right. In this embodiment, it can be selected to reduce to a closer boundary value.

[0015] Specifically, the environmental conditions include: a combination of time periods and weather conditions; the time periods include at least daytime and nighttime; the weather conditions include at least possible weather types such as sunny, cloudy, rainy, windy, snowy, foggy and haze; the environmental conditions can be expressed in the form of "daytime - sunny", "daytime - rainy, windy", "nighttime - snowy" and the like.

[0016] Specifically, the iterative update for the same environmental conditions as in S3 includes: in the subsequent time of the same environmental conditions as in S3, the average headway distance corresponding to the discrete vehicle speed value that is the same as the vehicle speed value of the reduced discrete vehicle speed in S3 is used to iteratively update the average headway distance calculated in the previous time in the corresponding table; wherein a corresponding table of discrete vehicle speeds and average headway distances is established for each environmental condition. The corresponding table of discrete vehicle speeds and average headway distances under different environmental conditions needs to be continuously updated using the vehicle driving data generated in the target lane in the subsequent time, so that the table always reflects the latest traffic status of the current interconnection.

[0017] Specifically, in S5, the adaptive control of the intercommunication flow at least includes: obtaining the vehicle data of the vehicle currently traveling on the target lane, and reducing it again using the current vehicle data to obtain the reduced discrete vehicle speed and average headway; if the average headway at this time is less than the safe merging distance corresponding to the discrete vehicle speed recorded in the corresponding table, it is determined that the state of the ramp vehicle merging into the main line is unsafe at this time, and corresponding flow limiting measures can be taken at the checkpoint at the ramp entrance to prohibit or slow down the ramp vehicle from merging into the main line. In the preferred embodiment, twice the average headway in the table corresponding to the discrete vehicle speed and the average headway is used as the safe merging distance corresponding to the discrete vehicle speed.

[0018] The adaptive control method for highway interchange provided by the embodiment of the present invention is based on the actual data of a large number of vehicles safely merging, and uses big data to calculate the average headway distance, providing a calculation method for the safe driving distance of vehicles merging into the main line of the highway interchange ramp, and providing a basis for controlling the safe merging of ramp vehicles. In practical applications, since the corresponding table can be continuously refreshed, the longer the use, the more stable the results can be obtained. In addition, for each different interchange, different time periods and weather conditions are comprehensively considered, and different corresponding tables are generated accordingly, which is highly targeted. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the following drawings describe only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A schematic diagram of a method flow chart provided by an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of ramp vehicles merging into the main line in a specific example provided by an embodiment of the present invention. The main elements in the figure include a radar-vision integrated device, a merging area, vehicles in the target lane, vehicles that safely merge into the target lane from the ramp, and other vehicles. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0023] The purpose of the present invention is to provide a scientific method for determining the safe driving distance of highway vehicles and the timing of ramp vehicles merging into the main line under different environmental conditions under current driving conditions, so as to provide a basis for highway driving safety and ramp adaptive control.

[0024] Specifically, an embodiment of the present invention provides an adaptive control method for highway interconnection, such as Figure 1 As shown, including:

[0025] S0. Real-time monitoring of the outermost lane of the main line merging area, i.e., the target lane; for different interchanges, the length of the target lane may vary according to the actual situation; the main line merging area is the main line area from the beginning to the end of the merging of the ramp and the main line; Figure 2 As shown;

[0026] Preferably, a radar-vision integrated device is used to monitor the target lane in real time to capture relevant parameters such as the number of vehicles in the target lane, the head-to-head distance, and the vehicle speed.

[0027] S1. When a vehicle is detected to be safely merging into a target lane from an interchange ramp, the number of vehicles traveling in the target lane at that time, the speed of each vehicle, and the headway between two adjacent vehicles are obtained;

[0028] Preferably, a radar-vision integrated device is used to determine the behavior of vehicles merging safely from the ramp into the target lane. The obtaining of the headway distance between two adjacent vehicles traveling on the target lane at that time includes: obtaining the distance between the headway of a vehicle in the target lane and the headway of the vehicle immediately behind the vehicle; in particular, for the last vehicle in the target lane, the distance from the vehicle to the end of the target lane can be taken as the headway distance.

[0029] S2, calculating the average headway between adjacent vehicles in the target lane; at the same time, calculating the average speed of the vehicles in the target lane;

[0030] The average headway between adjacent vehicles in the target lane is the average of the distances between the head of each vehicle in the target lane and the head of the vehicle immediately behind the vehicle; the average speed of the vehicle is the average of the speeds of all vehicles in the target lane.

[0031] S3, discretizing the average vehicle speed so that the average vehicle speed is reduced to one of a number of different discrete vehicle speeds, and making the discrete vehicle speed correspond to the average headway between vehicles in the target lane at this moment;

[0032] The discretization processing of the average vehicle speed includes:

[0033] The possible minimum and maximum values ​​of the vehicle speed in the target lane are taken as the speed interval, and a number of discrete speed points are taken within the speed interval to divide the speed interval into a number of small speed intervals; the small speed interval in which the average speed is located is determined, and the average speed is reduced to one of the boundary values ​​of the small speed interval.

[0034] S4. In combination with environmental conditions, the average headway distance corresponding to the same environmental conditions and the same discrete vehicle speed in the subsequent time is used to iteratively update the average headway distance calculated under the same conditions in the previous time, and finally a corresponding table of discrete vehicle speeds and average headway distances under different environmental conditions is obtained.

[0035] The environmental conditions include: a combination of time periods and weather conditions; the time periods include at least daytime and nighttime; the weather conditions include the types of weather that the location of the interconnection may face, such as sunny, cloudy, rainy, windy, snowy, foggy, haze, etc.; the environmental conditions can be expressed in the form of "daytime - sunny", "daytime - rainy, windy", "nighttime - snowy", and the like.

[0036] The correspondence table between discrete vehicle speeds and average headway distances under different environmental conditions needs to be continuously updated using vehicle driving data generated in the target lane in the subsequent period of time, so that the table always reflects the latest traffic status of the current interconnection.

[0037] S5. Based on the correspondence table between discrete vehicle speeds and average headway distances, adaptive control is performed on the intercommunication traffic.

[0038] The twice of the average headway distance in the table of correspondence between discrete vehicle speeds and average headway distances is recorded as the safe merging distance corresponding to the corresponding discrete vehicle speed.

[0039] The reduced discrete vehicle speed and average headway of the vehicle currently traveling on the target lane are obtained. If the average headway is smaller than the safe merging distance corresponding to the same discrete vehicle speed in the table, it is determined that it is unsafe for the ramp vehicle to merge into the main line at this time. Corresponding flow limiting measures can be taken at the checkpoint at the ramp entrance to prohibit or slow down the ramp vehicle from merging into the main line.

[0040] In this embodiment, in S3, the vehicle speed interval can be evenly divided into several small vehicle speed intervals with a speed increment of 5 km / h, and the discrete vehicle speeds are defined as the boundary values ​​of these small vehicle speed intervals. Assuming that the maximum average speed in the target lane obtained by the integrated radar vision device is 150km / h and the minimum average speed is 0km / h, the speed range of the target lane is [0km / h, 150km / h]; within this speed range, a number of discrete speed points of 5km / h, 10km / h, 15km / h, 20km / h, ..., 140km / h, 145km / h are taken in this range with a speed increment of 5km / h, and the speed range [0km / h, 150km / h] is divided into a number of small speed ranges [0km / h, 5km / h], [5km / h, 10km / h], [10km / h, 15km / h], [15km / h, 20km / h], ..., [140km / h, 145km / h], [145km / h, 150km / h];

[0041] Furthermore, for the average speed falling within a certain small speed interval, the average speed is reduced to the boundary value of the small speed interval closer to the average speed; if the average speed is exactly in the middle of the small speed interval, the average speed is reduced to the boundary value on the right side of the small speed interval; for example, for the small speed interval [100km / h, 105km / h], assuming the average speed is 101km / h, the speed is reduced to 100km / h; assuming the average speed is 102.5km / h, the speed is reduced to 105km / h; assuming the average speed is 104.5km / h, the speed is reduced to 105km / h.

[0042] In this embodiment, in S4, in actual application, the weather conditions can be appropriately adjusted according to the climate environment in which the communication is located to cover most weather types; the weather conditions can also be divided more finely and different weather types can be divided according to levels.

[0043] Among them, the correspondence table between different discrete vehicle speeds and average headway distances under different environmental conditions needs to be continuously updated using the vehicle driving data generated by the target lane in the subsequent time, so that the table always reflects the latest traffic status of the current interchange.

[0044] For example, the table of correspondence between discrete vehicle speed and average headway can be updated in the following way. Taking the "daytime-sunny" environment condition as an example, assuming that after the vehicle safely merges into the main line from the ramp, the reduced discrete vehicle speed in the target lane is 90km / h, the average headway is 50m, and the number of vehicles in the target lane is 5;

[0045] Table 1 Correspondence between initial discrete vehicle speed and average headway

[0046]

[0047] In the subsequent time, if the environmental condition is also "daytime-sunny", after a vehicle completes the safe merging from the ramp to the main line, the reduced discrete speed in the target lane is also 90km / h, and the average headway at this time is 60m, and the number of vehicles in the target lane is 4; then the updated number of vehicles is 5+4=9, and the updated average headway is (50m*5+60m*4) / (5+4)=54.44m, that is:

[0048] Table 2 Updated correspondence between discrete vehicle speed and average headway

[0049]

[0050] The corresponding table of discrete vehicle speed and average headway distance under other environmental conditions can be calculated in the same way. The corresponding table of discrete vehicle speed and average headway distance can be established and stored in a relational database.

[0051] In this embodiment, in S5, a table of correspondence between discrete vehicle speeds and average headway distances can be used as a basis for controlling the safe merging of interchange ramp vehicles into the main line: twice the average headway distance in the table is recorded as the safe merging distance corresponding to the corresponding discrete vehicle speed; before the ramp vehicle merges into the main line, the real-time average headway distance corresponding to the reduced discrete vehicle speed of the vehicle in the target lane is captured; if this real-time average headway distance is greater than or equal to the safe merging distance corresponding to the same discrete vehicle speed in the corresponding table, it is considered that the timing for the ramp vehicle to merge into the target lane at this moment is safe; otherwise, it is considered that the timing for the ramp vehicle to merge into the main line is unsafe, and corresponding measures can be taken for the vehicles on the ramp to merge into the main line to prohibit or slow down the merging of the ramp vehicle into the main line.

[0052] For example, the specific implementation process of this embodiment in practical application may include:

[0053] The climate conditions in the area where a certain interchange is located are mainly sunny, rainy, snowy, and foggy. The length of the merging area of ​​the interchange is 250m, and the radar-visual integrated device is used to detect the outer lane of the merging area (target lane). On a certain day when the weather at the interchange is sunny, at a certain moment, a vehicle merges safely from the ramp into the main line. The radar-visual integrated device captures the merging behavior of the vehicle, and counts that there are 5 vehicles in the target lane at this moment, with an average speed of 91.3km / h and an average headway of 48.2m; the average speed is reduced to the nearest boundary value of 90km / h in the small speed interval [90km / h, 95km / h] as the reduced discrete speed; the reduced discrete speed, average headway and number of vehicles in the target lane are added to the corresponding table of discrete speed and average headway under the "daytime-sunny" environmental condition stored in the relational database.

[0054] Table 3 Correspondence between discrete vehicle speed and average headway distance under daytime-sunny environment conditions

[0055]

[0056] In the subsequent time, if the environmental factor is also sunny during the day, and another vehicle merges safely into the main line from the ramp, the radar vision integrated device captures the merging behavior of the vehicle, and then counts the number of vehicles in the target lane at this moment as 4, with an average speed of 89.1km / h and an average headway of 49.7m; the average speed is reduced to the nearest boundary value of 90km / h in the small speed range [85km / h, 90km / h] as the reduced discrete speed; since the discrete speed of 90km / h already exists in the corresponding table of discrete speed and average headway under the "daytime-sunny" environmental condition, the current data needs to be used to update the existing data in the table:

[0057] Update the number of vehicles to: 5+4=9;

[0058] Update the average headway to: (48.2*5+49.7*4) / (5+4)=48.87;

[0059] The updated correspondence table is:

[0060]

[0061] When a vehicle safely merges under the same environmental conditions, the data in the table is calculated or updated in the same way to obtain the final correspondence table between discrete vehicle speed and average headway distance under the "daytime-sunny" environmental condition.

[0062]

[0063] The corresponding table of discrete vehicle speed and average headway distance under environmental conditions such as "daytime - rain", "nighttime - snow", and "daytime - fog" is calculated in the same way as the corresponding table of discrete vehicle speed and average headway distance under the environmental condition of "daytime - sunny".

[0064] Table 4 Correspondence between discrete vehicle speed and average headway distance under daytime-rainy environment

[0065]

[0066] Table 5 Correspondence between discrete vehicle speed and average headway distance under night-time snowy environment

[0067]

[0068] Table 6 Correspondence between discrete vehicle speed and average headway distance in daytime-fog environment

[0069]

[0070]

[0071] The correspondence table between discrete vehicle speeds and average headway distances under different environmental conditions can be used as a reference for the safe driving distance at the corresponding interchange under the same environmental conditions.

[0072] In combination with specific application scenarios, a solution of Embodiment 2 may be designed, including:

[0073] The climate conditions in the area where a certain interchange is located are mainly sunny and rainy. The length of the merging area of ​​the interchange is 300m. The radar-visual integrated device is used to detect the outer lane of the merging area (target lane). On a certain day when the weather of the interchange is sunny, at a certain moment, a vehicle merges safely into the main line from the ramp. The radar-visual integrated device captures the merging behavior of the vehicle and counts that there are 6 vehicles in the target lane at this moment, with an average speed of 85.1km / h and an average headway of 49.4m; the average speed is reduced to the nearest boundary value of 85km / h in the small speed interval [85km / h, 90km / h] as the reduced discrete speed; the reduced discrete speed, average headway and number of vehicles in the target lane are added to the corresponding table of discrete speed and average headway under the "daytime-sunny" environmental condition stored in the relational database.

[0074] Table 7 Correspondence between discrete vehicle speed and average headway distance under daytime-sunny environment conditions

[0075]

[0076] In the subsequent time, if the environmental factor is also sunny during the day, and another vehicle merges safely into the main line from the ramp, the radar vision integrated device captures the merging behavior of the vehicle, and then counts the number of vehicles in the target lane at this moment as 7, the average speed is 83.7km / h, and the average headway is 41.9m; ​​the average speed is reduced to the nearest boundary value of 85km / h in the small speed range [80km / h, 85km / h] as the reduced discrete speed; because the discrete speed of 85km / h already exists in the corresponding table of discrete speed and average headway under the "daytime-sunny" environmental condition, it is necessary to use the current data to update the existing data in the table:

[0077] Update the number of vehicles to: 6+7=13;

[0078] Update the average headway to: (49.4*6+41.9*7) / (6+7)=45.36;

[0079] The updated correspondence table is:

[0080]

[0081] When a vehicle safely merges under the same environmental conditions, the data in the table is calculated or updated in the same way to obtain the final correspondence table between discrete vehicle speed and average headway distance under the "daytime-sunny" environmental condition.

[0082]

[0083] The corresponding table of discrete vehicle speed and average headway distance under environmental conditions such as "daytime - rainy", "nighttime - sunny", and "nighttime - rainy" is calculated in the same way as the corresponding table of discrete vehicle speed and average headway distance under environmental conditions such as "daytime - sunny".

[0084] Table 8 Correspondence between discrete vehicle speed and average headway distance under daytime-rainy environment conditions

[0085]

[0086] The correspondence table between discrete vehicle speeds and average headway distances under different environmental conditions can be used as a reference for the safe driving distances at the corresponding interchanges under the same environmental conditions, and can also be used as a basis for controlling the safe merging of vehicles on interchange ramps into the main line under the same environmental conditions: before the vehicle merges into the main line, if the average headway distance of the captured vehicles in the target lane at the reduced discrete vehicle speed is greater than or equal to twice the average headway distance at the same discrete vehicle speed in the corresponding table, it is considered that the timing for the vehicle to merge into the target lane at this moment is safe; otherwise, it is considered that the timing for the vehicle to merge into the main line is unsafe, and corresponding measures can be taken to prohibit the vehicle from merging into the main line on the ramp.

[0087] For this interchange, assume that at a certain moment, the average speed of vehicles on the target lane of the interchange captured by the radar vision integrated device is 78.9 km / h, the average headway is 86.7 m, and the environmental condition is "daytime - sunny"; the discrete speed after reducing the average speed is 80 km / h. By looking up the corresponding table of discrete speed and average headway under the environmental condition of "daytime - sunny", it can be seen that the average headway corresponding to the discrete speed of 80 km / h is 42.71 m. Since 86.7 m>=2*42.71 m, it can be considered that it is safe for vehicles to merge into the main line from the ramp at this moment, and the ramp vehicles can be released.

[0088] Assume that at a certain moment, the average speed of vehicles on the interchange target lane captured by the radar vision integrated device is 81.4km / h, the average headway is 96.1m, and the environmental condition is "daytime-rainy"; the discrete speed after reducing the average speed is 80km / h. By looking up the corresponding table of discrete speed and average headway under the "daytime-rainy" environmental condition, it can be seen that the average headway corresponding to the discrete speed of 80km / h is 51.06m. Since 96.1m<2*51.06m, it can be considered that it is unsafe for vehicles to merge into the main line from the ramp at this moment, and it is necessary to suspend or prohibit vehicles on the ramp.

[0089] In this embodiment, the average headway distance can be calculated in a big data manner based on the actual data of a large number of vehicles safely merging, which provides a calculation method for the safe driving distance for vehicles merging into the main line at the interchange ramp of the highway, and provides a basis for controlling the safe merging of vehicles on the ramp. The longer the use, the more stable the results can be, which is scientific; different corresponding tables are generated for different interchanges, which is highly targeted; different time periods and weather conditions are comprehensively considered, which is highly adaptable; the situations under assisted driving and automatic driving conditions are coordinated, which is forward-looking; the calculation logic of this method is simple, the technical solution is easy to implement, and it has strong ease of use and good promotion and application value.

[0090] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An adaptive control method for highway interchanges, It is characterized in that include: S0. Real-time monitoring of the outermost lane of the main line merging area of ​​the expressway and using it as the target lane; The main line merging area includes the main line area from the beginning to the end of the merging of the ramp and the main line of the expressway; S1. When a vehicle is detected merging into the target lane from the interchange ramp, vehicle data of the vehicles traveling in the target lane is obtained, wherein the vehicle data includes the number of vehicles, the speed of each vehicle, and the headway between two adjacent vehicles; S2, calculating the average headway between adjacent vehicles in the target lane, and calculating the average speed of the vehicles in the target lane; S3, discretizing the average vehicle speed, and reducing the discretized average vehicle speed to one of the discrete vehicle speeds, wherein the reduced discrete vehicle speed corresponds to the average headway of vehicles in the target lane at this moment; S4, iteratively updating the calculated average headway distance, wherein the iterative update is divided according to environmental conditions, and by iteratively updating for different environmental conditions, a corresponding table between discrete vehicle speeds and average headway distances under different environmental conditions is obtained; S5, using the correspondence table between discrete vehicle speeds and average headway distances to adaptively control the intercommunication flow; In S5, adaptively controlling the intercommunication traffic at least includes: obtaining vehicle data of vehicles currently traveling on the target lane, and reducing again using the current vehicle data to obtain reduced discrete vehicle speeds and average headway distances; If the average headway at this time is less than the safe merging distance corresponding to the discrete vehicle speed recorded in the corresponding table, it is determined that the state of the ramp vehicle merging into the main line at this time is unsafe; The twice of the average headway distance in the table of correspondence between discrete vehicle speeds and average headway distances is used as the safe merging distance corresponding to the discrete vehicle speed.

2. The method according to claim 1, It is characterized in that In S1, the headway distance between two adjacent vehicles is obtained, including: Obtaining the distance between the front of a vehicle in the target lane and the front of a vehicle immediately behind the vehicle; If the vehicle in the acquired target lane is the last vehicle in the target lane, the distance from the vehicle to the end of the target lane is taken as the headway.

3. The method according to claim 1 or 2, It is characterized in that In S2, the average headway distance between adjacent vehicles in the target lane is: the average of the distances between the head of each vehicle in the target lane and the head of the vehicle immediately behind the vehicle; the average speed of the vehicle is the average of the speeds of all vehicles in the target lane.

4. The method according to claim 1, It is characterized in that In S3, the discretization process of the average vehicle speed includes: A speed interval is established by taking the minimum and maximum speeds of all vehicles in the target lane as boundary values ​​of the interval, taking at least one discrete speed point in the speed interval, and dividing the speed interval into small speed intervals by the discrete speed points; The low vehicle speed interval in which the average vehicle speed is located is determined, and the average vehicle speed is reduced to one of the boundary values ​​of the low vehicle speed interval in which the average vehicle speed is located.

5. The method according to claim 1, It is characterized in that The environmental conditions include: a combination of time period and weather conditions; The time period at least includes: daytime and nighttime; The weather conditions include at least: sunny, cloudy, rainy, windy, snowy, foggy and hazy.

6. The method according to claim 1, It is characterized in that By iteratively updating according to different environmental conditions, a corresponding table of discrete vehicle speeds and average headway distances under different environmental conditions is obtained, including: Combined with the environmental conditions, the average headway distance corresponding to the same environmental conditions and the same discrete vehicle speed in the subsequent time is used to iteratively update the average headway distance calculated under the same conditions in the previous time, and finally a corresponding table of discrete vehicle speeds and average headway distances under different environmental conditions is obtained; Among them, a correspondence table between discrete vehicle speeds and average headway distance is established for each environmental condition.

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