A method for expressway mainline lane management and control and entry ramp coordinated control

Abstract

The application relates to a fast road main line lane control and entrance ramp cooperative control method, and belongs to the intelligent transportation field. The method comprises the following steps: S1, multiple vehicle detectors are respectively installed on the main line lane and the entrance ramp, and lane flow, vehicle speed and density of corresponding detection points are acquired; S2, a main line lane control model is constructed: the lane expected flow rate ratio of vehicles driving to the merging area on the main line is calculated, then the traffic operation state level of each lane on the main line at the merging area is obtained in combination with traffic operation state level division rules, and the level is adjusted according to the conditions of each lane; and S3, an entrance ramp control model is constructed: the entrance ramp adjustment rate in the current control period is calculated, and is compared with the ramp traffic flow to judge, so that the green light duration of the ramp control signal lamp is obtained. The application can increase the traffic flow of the ramp into the main line, improve the traffic capacity of the merging area, and reduce the lane changing times of vehicles in the merging area.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of intelligent transportation, and relates to a method for coordinated control of main line lane management and control and entrance ramp of expressway. BACKGROUND

[0002] Since the vehicles on the entrance ramp of expressway merge into the main line at the merging area, which only interferes with the two outer lanes of the main line, the existing control strategy of the entrance ramp does not consider this special situation, and is not coordinated with the main line lane management and control, so that the control of the entrance ramp is not effective in the application of multi-lane expressway. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a method for coordinated control of main line lane management and control and entrance ramp of expressway, which overcomes the problems of low utilization rate of inner lanes, frequent lane changing at the merging area, and drivers unable to know the lane marking method and traffic running conditions of the front merging area in advance in the control strategy of the entrance ramp of multi-lane expressway, improves the traffic capacity of the merging area of the main line, reduces the risk of traffic safety, and improves the fine management level of the merging area of expressway.

[0004] To achieve the above purpose, the present application provides the following technical scheme:

[0005] A method for coordinated control of main line lane management and control and entrance ramp of expressway, specifically comprising the following steps:

[0006] S1: installing a plurality of vehicle detectors on the main line lane and the entrance ramp respectively to obtain the lane flow, speed and density information of the corresponding detection points; specifically including:

[0007] On the main line lane, vehicle detector I, vehicle detector II and vehicle detector III are installed at the merging area, 50m upstream of the ramp merging nose, and 0.5km upstream of the installation position of the LED information release screen, respectively, to obtain the traffic flow data of each lane of the main line;

[0008] On the entrance ramp, a ramp control signal lamp is arranged at the entrance of the acceleration lane, a stop line is arranged 15m to 40m upstream of the entrance ramp from the ramp control signal lamp, and a vehicle detector IV is arranged;

[0009] S2: constructing a main line lane management and control model, specifically including: using the traffic flow of each lane upstream of the main line obtained by the vehicle detector III and the ramp traffic flow obtained by the vehicle detector IV, calculating the traffic flow at the vehicle detector III in the current control period k, and thus calculating the lane expected flow rate ratio of the vehicles driving to the merging area on each lane of the main line; then combining the traffic running state grade division rule to obtain the traffic running state grade of each lane of the merging area of the main line, and adjusting the grade according to the situation of each lane;

[0010] S3: constructing an entrance ramp control model, specifically comprising: calculating the entrance ramp adjustment rate in the current control period k by subtracting the traffic flow of the two lanes outside the main line obtained by the vehicle detector II from the capacity of the two lanes outside the main line, and comparing it with the ramp traffic flow obtained by the vehicle detector IV to determine the length of time for which the green light of the ramp control signal lamp is kept.

[0011] S4: determining whether the average speed of the two lanes outside the main line of the merging area is not greater than the free-flow speed of the main line multiplied by a reduction factor, or whether the sum of the traffic flow of the two lanes outside the main line upstream and the ramp traffic flow is not greater than the capacity of the two lanes outside the main line of the merging area multiplied by a reduction factor; if so, the entrance ramp control model is started; otherwise, the main line lane control model is started.

[0012] Further, in step S1, within the range of 0.5 km to 1.5 km upstream of the main line from the merging area, an LED information release screen is installed to release the lane control traffic state of the merging area to remind the driver to choose the driving lane in advance.

[0013] Further, in step S1, the lane line between the inner two lanes and the outer two lanes on the main line is painted as a solid line to avoid interference of ramp merging with the inner two lanes.

[0014] Further, in step S1, the content displayed on the LED information release screen includes:

[0015] (1) the painting method of each lane line and edge line of the merging area, and which one of solid line, dashed line, and dashed-solid line it belongs to, so that the driver can determine whether each lane of the merging area is allowed to change lanes, and whether it is allowed to change lanes to the left or to the right; the painting method of the lane line and edge line displayed on the LED information release screen needs to be consistent with the actual painting method of the merging area ahead;

[0016] (2) the traffic state of each lane of the merging area, which is displayed by a color bar; the driver can determine the traffic state of each lane of the merging area according to the color displayed by the color bar, combined with the painting method of the marking line and the lane number marker displayed on the LED information release screen, so as to serve as a judgment information condition for the driver to choose the lane in advance;

[0017] (3) graphical display with text.

[0018] Further, in step S2, the calculation formula of the lane flow rate ratio of the merging area is:

[0019]

[0020]

[0021]

[0022]

[0023] Where, p i (k) represents the expected flow rate ratio of lane i in the merging zone control cycle k; i∈{1,2,3,4} represent mainline lane 1, lane 2, lane 3 and lane 4 respectively; Traffic flow in lane i during control period k, pcu / h, obtained by vehicle detector III; The control period k is the ramp traffic flow obtained by vehicle detector IV, pcu / h; c0 is the mainline single-lane capacity, pcu / h; λ3 is the proportion of the ramp merging flow to the mainline lane 3, 0≤λ3<0.5; λ4 is the proportion of the ramp merging flow to the mainline lane 4, 0.5<λ4≤1.0, λ3+λ4=1.

[0024] Furthermore, in step S2, the level is adjusted according to the condition of each lane, specifically including: if the operating status level of lane 1 and lane 2 is not lower than that of lane 3 and lane 4, the operating status level of lane 1 and lane 2 is adjusted to one level lower than that of lane 3 and lane 4; wherein, based on the direction of travel, the main line lanes are numbered from left to right as lane 1, lane 2, lane 3 and lane 4 respectively.

[0025] Furthermore, in step S3, the regulation rate of the k-entry ramp in the current control cycle is calculated, and the expression is:

[0026]

[0027] Where r(k) is the ramp regulation rate during control period k, pcu / h; c 34 The capacity of the two lanes outside the main line in the merging zone is measured in pcu / h. Traffic flow rate (pcu / h) of the two outer lanes of the main line during control period k, obtained by vehicle detector II.

[0028] Furthermore, in step S3, the ramp adjustment rate of the current control period k is compared with the ramp traffic flow obtained by vehicle detector IV. If the ramp adjustment rate r(k) is not less than the ramp traffic flow obtained by vehicle detector IV, the following judgment is made: If the ramp control signal light remains green, then the green light duration for the ramp control signal light will be calculated.

[0029]

[0030] Where T(k) is the duration of control cycle k, in seconds; g(k) is the green light duration of the ramp control signal light in control cycle k, in seconds; s rThe saturation flow rate of the ramp is pcu / h.

[0031] The beneficial effects of this invention are as follows: This invention can be applied to merging areas of expressways, highways, ordinary roads, and urban roads for refined and intelligent management of merging areas. By setting up LED information display screens upstream of the mainline merging area to show the lane traffic status of the merging area ahead and the merging situation of vehicles from ramps, it guides drivers to choose the inner lane in advance to balance the traffic flow of each lane in the merging area, reduce the traffic flow of the two outer lanes of the mainline, increase the utilization rate of the inner lanes, increase the traffic flow of ramps merging into the mainline, improve the traffic capacity of the merging area, and at the same time reduce the number of lane changes in the merging area, ensuring efficient, safe, and smooth traffic operation in the merging area.

[0032] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0034] Figure 1 This is a schematic diagram of the expressway mainline lane control and entrance ramp coordinated control system of the present invention;

[0035] Figure 2 This is a flowchart of the method for coordinated control of mainline lane management and entrance ramps on expressways according to the present invention;

[0036] Figure 3 This is a schematic diagram of an LED information display screen. Detailed Implementation

[0037] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0038] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0039] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0040] Please see Figures 1-3 This invention provides a mainline lane control and entrance ramp coordination control system for expressways, comprising:

[0041] 1. The collaborative control system includes a mainline lane control module and an entrance ramp control module.

[0042] The mainline lane control module is located 0.5km to 1.5km upstream of the merging zone on the mainline. It displays lane traffic status during the merging phase via LED information displays to remind drivers to choose their lanes in advance. The mainline lanes are numbered from left to right as Lane 1, Lane 2, Lane 3, and Lane 4, based on the direction of travel. Road markings indicating "Lane 1," "Lane 2," "Lane 3," and "Lane 4" are painted on the mainline lanes at the LED information display locations. The outer two lanes within a merging zone extending 450m downstream from the merging nose of the ramp are designated as the merging zone. Within this zone, the lane line between Lane 2 and Lane 3 is painted as a solid line to avoid interference from the merging on the inner two lanes. Vehicle detectors 1, 2, and 3 are installed in the merging impact zone, 50m upstream of the merging nose of the ramp, and 0.5km upstream of the LED information display locations to collect traffic flow data for each lane on the mainline.

[0043] The entrance ramp control module is set on the entrance ramp of the merging area to adjust the merging flow of the ramp to avoid serious interference with the main line; a ramp control signal light is set on the entrance ramp at the starting point of the acceleration lane, and a stop line is set upstream of the entrance ramp 15m to 40m away from the ramp control signal light. At the same time, vehicle detector 4 is set.

[0044] 2. The LED information display screen in the mainline lane control module displays the following content:

[0045] 1) The marking method of each lane line and edge line in the merging area, and whether it is a solid line, dashed line, or a combination of solid and dashed lines, is used to help drivers determine whether lane changes are permitted in the merging area, and whether lane changes to the left or right are allowed. The marking method of lane lines and edge lines displayed on the LED information display screen must be consistent with the actual marking method of the merging area ahead.

[0046] 2) The traffic status of each lane in the merging area is displayed via lane status color bars. The display colors and corresponding traffic statuses are shown in Table 1. Drivers can determine the traffic status of each lane in the merging area by combining the lane markings and lane number markings displayed on the LED information display screen with the colors shown on the lane status color bars. This information serves as a basis for drivers to make informed lane selection decisions.

[0047] Table 1 RGB values ​​for traffic operation status display color scheme

[0048] Status level Uncongested Moderately congested Severely congested Color scheme Rank number Status level 1 2 3 4 5 R 0 153 255 255 255 G 128 204 255 153 0 B 0 0 0 0 0

[0049] 3) Since the first two items are both graphic, in order to improve the recognizability of the LED information display screen, a text prompt message is added: "Pay attention to the status of each lane in the merging area, please select your driving lane in advance."

[0050] 3. Adopt a coordinated release of control strategies between the mainline lane control module and the entrance ramp control module.

[0051] Step 1: Use vehicle detectors to obtain lane-specific traffic flow, speed, and density information at each detection point. Proceed to Step 2, and simultaneously determine whether the average speed of vehicles in the two outer lanes of the merging zone is not greater than the free-flow speed of the mainline multiplied by a reduction factor, or whether the sum of the traffic flow from the upstream mainline's two outer lanes and the ramp traffic flow is not greater than the capacity of the two outer lanes of the merging zone's mainline multiplied by a reduction factor. If so, proceed to Step 3. The judgment conditions are as follows:

[0052]

[0053]

[0054] in, The control period k is the average vehicle speed (km / h) of the two outer lanes of the main line obtained by vehicle detector 1; υ f Main free-flow velocity, km / h; δ υ The reduction factor for the velocity judgment condition is 0 ≤ δ υ ≤1; The traffic flow (pcu / h) of the two outer lanes of the main line during the control period k obtained by vehicle detector 2; Traffic flow at ramp k, pcu / h, obtained from vehicle detector 4 during control period k; 34 The capacity of the two lanes outside the mainline in the merging zone is pcu / h; δ q The reduction factor for flow rate determination, 0 ≤ δ q ≤1.

[0055] Step 2: Activate the mainline lane control module.

[0056] Step 2.1: Using the traffic flow of each lane upstream of the main line obtained by vehicle detector 3 and the ramp traffic flow obtained by vehicle detector 4, calculate the traffic flow at vehicle detector 3 in the current control cycle k. If the expected flow rate ratio of each lane is to be formed when traveling to the merging zone, the calculation formula is shown in equations (3) to (6). The traffic operation status of each lane in the merging zone is given in conjunction with Table 2.

[0057]

[0058]

[0059]

[0060]

[0061] Where, p i (k) represents the expected flow rate ratio of lane i in the merging zone control cycle k; i∈{1,2,3,4} represent lane 1, lane 2, lane 3 and lane 4 respectively; λ is the traffic flow on lane i in control period k obtained by vehicle detector 3, pcu / h; c0 is the single-lane capacity of the main line, pcu / h; λ3 is the proportion of the inflow from the ramp to the main line lane 3, 0≤λ3<0.5; λ4 is the proportion of the inflow from the ramp to the main line lane 4, 0.5<λ4≤1.0, λ3+λ4=1.

[0062] Table 2 Classification of Traffic Operation Status Levels

[0063] Uncongested 1 2 3 4 5 Moderately congested Severely congested Value range Color scheme ​ ​ ​ [[0, γ1]] [(γ1, γ2]] [(γ2, γ3]] [(g3, g4)] [(γ4, 1]] ​ 1 2 3 4 5

[0064] Note: In Table 2, γ j The threshold for classifying the running status level is j∈{1,2,3,4}.

[0065] Step 2.2: If the operating status level of lane 1 and lane 2 is not lower than that of lane 3 and lane 4, adjust the operating status level of lane 1 and lane 2 to one level lower than that of lane 3 and lane 4.

[0066] Step 2.3: Input the above calculation results into the mainline lane control module, and use the LED information display screen to display the traffic operation status of the merging lanes ahead, reminding drivers to choose the appropriate lane in advance. Proceed to 3.4.

[0067] Step 3: Start the entrance ramp control module.

[0068] Step 3.1: Calculate the entrance ramp regulation rate by subtracting the traffic flow of the two outer lanes of the mainline obtained from vehicle detector 2 from the capacity of the two outer lanes of the mainline in the merging zone. See below.

[0069]

[0070] Where r(k) is the ramp regulation rate during control period k, pcu / h.

[0071] Step 3.2: If the ramp adjustment rate calculated above is not less than the ramp traffic flow obtained by vehicle detector 4, the ramp control signal light will remain green. Otherwise, the green light duration of the ramp control signal light will be calculated using formula (9).

[0072]

[0073] Where T(k) is the duration of control cycle k, in seconds; g(k) is the green light duration of the ramp control signal light in control cycle k, in seconds; s r The saturation flow rate of the ramp is pcu / h.

[0074] Step 3.3: Activate the ramp control lights, input the above calculation results into the ramp control lights, and execute the entrance ramp control strategy. Proceed to Step 4.

[0075] Step 4: At the end of each control cycle, determine whether to end the mainline lane control and entrance ramp coordinated control. If yes, end the control; if no, go to step 1, and at the same time determine whether the traffic data obtained by the detector in N consecutive cycles does not meet formula (1) and formula (2). If yes, close the entrance ramp control module; if no, go to step 3.1.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for lane-specific control and coordinated control of entrance ramps on a mainline of an expressway, characterized in that, The method specifically includes the following steps: S1: Multiple vehicle detectors are installed on the mainline lanes and entrance ramps to obtain lane flow, speed, and density at the corresponding detection points; specifically including: On the main line lanes, vehicle detector I, vehicle detector II and vehicle detector III are installed at the merging area, upstream of the merging nose of the ramp, and upstream of the LED information display screen installation location, respectively. On the entrance ramp, ramp control lights are installed at the entrance ramp at the starting point of the acceleration lane, and a stop line is installed upstream of the entrance ramp. At the same time, vehicle detector IV is installed. On the main road, the lane lines between the inner two lanes and the outer two lanes are painted as solid lines. S2: Construct a mainline lane-specific control model, specifically including: using the traffic flow of each lane upstream of the mainline obtained by vehicle detector III and the ramp traffic flow obtained by vehicle detector IV, to calculate the current control cycle. k The traffic flow at vehicle detector III and the ramp traffic flow at vehicle detector IV are used to calculate the expected flow rate ratio of vehicles traveling from each lane on the main line to the merging area. Then, the traffic operation status level of each lane on the main line in the merging area is obtained by combining the traffic operation status level classification rules, and the level is adjusted according to the situation of each lane. The traffic operation status level is numbered as 1, 2, 3, 4, and 5, which correspond to smooth flow, basically smooth flow, light congestion, moderate congestion, and severe congestion, respectively. The formula for calculating the lane expected flow ratio in the merging zone is: in, For the control cycle of the merging zone k Middle lane i Expected flow rate ratio; i ∈{1,2,3,4} represent lane 1, lane 2, lane 3 and lane 4 of the main line, respectively; Control cycle obtained for vehicle detector III k Middle lane i Traffic flow on the road; Control cycle obtained for vehicle detector IV k Ramp traffic flow; The main line has a single-lane capacity. The percentage of the impact of ramp merging traffic on mainline lane 3. ; The percentage of the impact of the ramp merging traffic on lane 4 of the main line. , ; The lane status will be adjusted according to the conditions of each lane. Specifically, if the operating status level of lane 1 and lane 2 is not lower than that of lane 3 and lane 4, the operating status level of lane 1 and lane 2 will be adjusted to one level lower than that of lane 3 and lane 4. The main lanes will be numbered as lane 1, lane 2, lane 3 and lane 4 from left to right based on the direction of travel. S3: Construct the entrance ramp control model, specifically including: calculating the current control cycle by subtracting the traffic flow of the two outer lanes of the mainline obtained by vehicle detector II from the capacity of the two outer lanes of the mainline in the merging zone. k The entry ramp adjustment rate is compared with the ramp traffic flow obtained by vehicle detector IV to determine the duration of the green light for the ramp control signal. S4: Determine whether the average speed of the two lanes outside the main line in the merging zone is not greater than the free-flow speed of the main line multiplied by the reduction factor; if so, start the entrance ramp control model calculation; otherwise, start the main line lane control model calculation.

2. The method for lane-specific control and entrance ramp coordinated control of expressway mainline according to claim 1, characterized in that, In step S1, within a range of 0.5km to 1.5km upstream of the merging zone on the main line, LED information display screens are installed to display the traffic status of the lanes in the merging zone.

3. The method for lane-specific control and coordinated control of entrance ramps on expressways according to claim 1, characterized in that, In step S1, the content displayed on the LED information display screen includes: (1) The marking method of each lane line and edge line in the merging area, and whether it is a solid line, dashed line, or a combination of solid and dashed lines, so as to help drivers judge whether lane changes are allowed in each lane of the merging area, and whether lane changes to the left or right are allowed; the marking method of lane lines and edge lines displayed on the LED information display screen must be consistent with the actual marking method of the merging area ahead. (2) The traffic status of each lane in the merging area is displayed by the lane status display color bar; the driver combines the merging area marking method and road lane number marking displayed on the LED information display screen, and judges the traffic status of each lane in the merging area according to the color displayed by each lane status display color bar, so as to use the judgment information conditions for the driver to select lanes in advance. (3) Graphics are supplemented by text display.

4. The method for lane-specific control and coordinated control of entrance ramps on expressways according to claim 1, characterized in that, In step S3, the current control cycle is calculated. k The entrance ramp regulation rate is expressed as: in, To control the cycle k The ramp adjustment rate; The capacity is two lanes outside the main line in the merging zone. Control cycle obtained for vehicle detector II k Traffic flow on the two outer lanes of the main line.

5. The method for lane-specific control and coordinated control of entrance ramps on expressways according to claim 1, characterized in that, In step S3, the current control cycle is... k The ramp adjustment rate is compared with the ramp traffic flow obtained by vehicle detector IV to determine the appropriate adjustment rate. Not less than the ramp traffic flow obtained by vehicle detector IV If the green light is applied, the ramp control signal light will remain constantly green; otherwise, the green light duration for the ramp control signal light will be calculated. in, To control the cycle k The duration of the cycle; To control the cycle k The duration of the green light for ramp control traffic lights; The saturation flow rate of the ramp.

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