A linkage control system and method for highway entrance ramps, toll booths and connecting intersections

Abstract

The present invention relates to a linkage control system and method for highway entrance ramps, toll booths, and connecting intersections, and belongs to the field of intelligent transportation technology. The linkage control method includes a vehicle exiting the highway control algorithm, a vehicle entering the highway control algorithm, and an intersection signal control algorithm; the vehicle exiting the highway control algorithm is linked to the toll booth discharge control module, by adjusting the number of various types of toll lanes enabled in the toll booth exit direction. The vehicle entering the highway control algorithm is linked to the entrance ramp control module and the toll booth discharge control module; the entrance ramp control module adjusts the timing and number of ramp vehicles merging into the main line according to the remaining traffic capacity of the merging area and the acceptable queue length of the ramp. The intersection signal control algorithm is linked to the toll booth discharge control module and the signal intersection control module; in a non-congested state, signal timing is performed with the goal of minimizing the average delay of vehicles at the intersection. The present invention can improve the overall traffic efficiency and ensure its traffic safety, efficiency, and smooth operation.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent transportation technology and relates to a linkage control system and method for an expressway entrance ramp, a toll station and a connecting intersection. Background Art

[0002] With the acceleration of urbanization, it's become common for highway toll stations to be located in urban areas. However, due to urban land restrictions, the distance between toll stations and connecting intersections is relatively close. This leads to increasingly frequent problems, such as congested queues at toll station entrances overflowing into connecting intersections, causing traffic congestion at intersections, and congested queues at toll station exits overflowing into toll stations due to the limited traffic capacity of connecting intersections. If toll station congestion persists, the congested queues will overflow into the main line, affecting vehicles on the main line from exiting the highway and posing certain driving safety risks. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a linkage control system and method for highway entrance ramps, toll stations and connecting intersections, so as to improve the overall traffic efficiency of highway toll stations and connecting intersections, and ensure their safe, efficient and smooth operation.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A linkage control system for highway entrance ramps, toll booths, and connecting intersections, including an entrance ramp control module, a toll booth discharge control module, and a signalized intersection control module;

[0006] The entrance ramp control module is arranged at the entrance ramp of the merging area of ​​the expressway, and two entrance ramps are arranged according to the number of merging areas. The two merging areas are numbered I and II, and are equipped with the following supporting features: a ramp signal light is arranged at the starting point of the acceleration lane, a ramp stop line is marked on the entrance ramp a certain distance (20m to 50m) upstream of the ramp signal light, and a ramp vehicle detector (k1, k2) is arranged. A main line vehicle detector (m1, m2) is arranged upstream of the main line of the merging area.

[0007] The toll station discharge control module is installed at the toll station to control the number of toll lanes of various types at the toll station. The toll plaza on the side close to the highway is called the inner plaza, and the other side is called the outer plaza. Detectors K4 and K6 are installed at the inner plaza and outer plaza of the toll station exit respectively. Detectors K3 and K5 are installed at the inner plaza and outer plaza of the toll station entrance respectively to obtain traffic data of the inner and outer plazas of the toll station.

[0008] The signalized intersection control module is set at the intersection connecting to the toll station, and is used to control the release of turning vehicles at the intersection; starting from the entrance road of the intersection connected to the toll station, the entrance roads are numbered as east, north, west and south entrances in a counterclockwise direction, and detectors k7, k8, k9 and k10 are respectively set correspondingly to obtain traffic data of each entrance road of the intersection.

[0009] Furthermore, the system's linkage control method includes a vehicle disembarking high-speed control algorithm, a vehicle entering high-speed control algorithm, and an intersection signal control algorithm;

[0010] The vehicle exit control algorithm is linked to the toll station discharge control module, which adjusts the number of various toll lanes enabled in the direction of the toll station exit to avoid congestion in the square in the direction of the toll station exit, affecting the main line vehicles from exiting the highway and causing driving safety hazards;

[0011] The vehicle access control algorithm links the entrance ramp control module and the toll station discharge control module; the entrance ramp control module adjusts the timing and number of ramp vehicles merging into the main line based on the remaining traffic capacity of the merging area and the acceptable queue length of the ramp to avoid traffic congestion in the merging area; if the queue length of the entrance ramp exceeds the acceptable queue length, the toll station entrance direction discharge control is implemented to reduce the traffic flow entering the highway from the toll station; at the toll station entrance direction, the toll station discharge control module adjusts the number of various types of toll lanes activated in the toll station entrance direction to ensure that the traffic flow entering the highway and the queue length in the square outside the toll station entrance direction meet the requirements, thereby avoiding congestion of the entrance ramp queue at the toll station or congestion of the queue in the square outside the toll station entrance direction at the connecting intersection;

[0012] The intersection signal control algorithm links the toll station discharge control module and the signal intersection control module; in a non-congested state, signal timing is performed with the goal of minimizing the average delay per vehicle at the intersection; at the same time, the following constraints must be met: the traffic capacity of the east entrance must ensure that the congestion queue at the east entrance does not extend to the toll station; the flow rate allowed to enter the lanes on the exit side of the east entrance at each turn of the intersection must ensure that the congestion queue outside the square in the direction of the toll station entrance will not extend to the connecting intersection; if the above intersection signal timing optimization model does not have an optimal solution, it means that the intersection is in a congested state, so signal timing is performed with the goal of maximizing the number of vehicles passing through the intersection, and the above constraints must also be met.

[0013] Furthermore, the vehicle high-speed control algorithm specifically includes the following steps:

[0014] S11: Using the traffic flow and queue length in the toll station exit direction obtained by detector k4, the minimum regulation rate in the toll station exit direction under the queue length constraint is calculated for the two charging types of ETC and MTC, as shown in formulas (1) to (3); then proceed to S12;

[0015]

[0016]

[0017]

[0018] Where: γ ab,min (k) is the minimum adjustment rate of toll station direction a and toll type b under the queue length constraint within k cycles, pcu / s; δ ab (k) is the proportion of toll station direction a that chooses toll type b within period k; q a (k) is the traffic flow in direction a of the toll station during period k, pcu / s; T a (k) is the control cycle length of the toll station direction a within the k cycle, s; τ ab (k) is the queue length of toll station direction a and toll type b in period k, pcu; τ ab,max is the queue length threshold for toll station direction a and toll type b, pcu; τ a,max is the maximum number of queued vehicles that can be accommodated in the toll station direction a, pcu; ε a is the acceptable queue length reduction coefficient for the toll station direction a, 0≤ε a ≤1; a is the direction of the toll station, a∈{1,2} represents the exit and entrance respectively; b is the toll type, b∈{E,M} represents ETC and MTC respectively;

[0019] S12: Taking into account the operating cost of the toll station and the time cost of drivers and passengers, under the constraints of the maximum number of toll lanes that can be enabled and the minimum adjustment rate, determine the actual adjustment rate of various toll lanes in the toll station exit direction, as shown in formula (4); the larger the actual adjustment rate value, the higher the operating cost of the toll station; the smaller the actual adjustment rate value, the higher the time cost of drivers and passengers; (a larger actual adjustment rate value results in a higher operating cost of the toll station; a smaller actual adjustment rate value results in a higher time cost of drivers and passengers); proceed to S13;

[0020]

[0021] Where: γ ab (k) is the actual adjustment rate of toll station direction a and toll type b in period k, pcu / s; μ ab is the service rate of a single lane of toll type b at toll station direction a, pcu / s; N abThe maximum number of toll lanes set for toll station direction a and toll type b;

[0022] S13: Under the premise that the traffic capacity is greater than the actual regulation rate, determine the minimum number of toll lanes required to be activated for each toll type at the toll station exit; then proceed to the intersection signal control algorithm;

[0023]

[0024] Where: n ab (k) is the number of toll lanes enabled for toll type b in direction a of the toll station during cycle k.

[0025] Furthermore, the vehicle high-speed control algorithm specifically includes the following steps:

[0026] S21: On-ramp control;

[0027] S211: Calculate the entrance ramp adjustment rate based on the remaining traffic capacity of the expressway merging area using the mainline flow obtained by the mainline detectors m1 and m2 upstream of the merging area, as shown in formula (6); then proceed to S212;

[0028]

[0029] Where: γ x (k) is the ramp adjustment rate of the merging area x in period k, pcu / s; c x is the merging area x capacity, pcu / s; q mx (k) is the upstream flow rate of the main line of the merging area x in period k, pcu / s; x is the merging area number, x∈{1,2} represents merging area 1 and merging area 2 respectively;

[0030] S212: Calculate the green light duration of the ramp signal light using the relationship between the ramp flow rate and the ramp regulation rate obtained by detectors k1 and k2, as shown in formula (7); then proceed to S213;

[0031]

[0032] Where: g x (k) is the duration of the green light of the ramp signal light in the merging area x in cycle k, s; C x (k) is the duration of the signal light cycle at the merging area x ramp within the k-cycle, s; s x is the saturation flow rate of the merging area x ramp, pcu / s; q x (k) is the flow rate of the merging area x ramp in period k, pcu / s;

[0033] S213: Calculate the minimum regulation rate of each entrance ramp under the queue length constraint, as shown in formula (8); determine whether there is an entrance ramp whose regulation rate is less than the corresponding minimum regulation rate; if so, go to S23; if not, go to S22;

[0034]

[0035]

[0036] Where: γ x,min (k) is the minimum ramp adjustment rate of the merging area x under the queue length constraint within the k-cycle period, pcu / s; T x (k) is the control period length of the confluence area x within the k period, s; ​​τ x (k) is the ramp queue length of the merging area x in period k, pcu; τ x,max is the maximum number of queued vehicles that can be accommodated on the entrance ramp of the merging area x, pcu; ε x is the acceptable queue length reduction factor for the merging area x entrance ramp, 0≤ε x ≤1;

[0037] S22: discharge control at the toll station entrance;

[0038] S221: Using the flow rate and queue length outside the toll station entrance direction obtained by detector k5, the minimum regulation rate of the toll station entrance direction under the queue length constraint is calculated for the two charging types of ETC and MTC, as shown in formulas (10) to (12); then proceed to S222;

[0039]

[0040]

[0041]

[0042] S222: Determine whether there is a certain toll type in the toll station entrance direction where the traffic capacity is still less than the minimum adjustment rate even when all toll lanes are activated; if so, set the allowed adjustment rate in the toll station entrance direction equal to the traffic capacity and proceed to S24; if not, proceed to S223;

[0043]

[0044]

[0045] Where: γ a (k) is the permissible adjustment rate of the toll station direction a within the k-cycle, pcu / s;

[0046] S223: Taking into account the operating costs of the toll station and the time costs of drivers and passengers, under the constraints of the maximum number of toll lanes that can be activated and the minimum adjustment rate, the actual adjustment rates of various toll lanes in the direction of the toll station entrance are determined, as shown in formula (15); then proceed to S224;

[0047]

[0048] S224: Under the premise that the traffic capacity is greater than the actual regulation rate, determine the minimum number of toll lanes that need to be activated for various toll types in the toll station entrance direction; then proceed to S24;

[0049]

[0050]

[0051] S23: Modification of discharge control at toll station entrance;

[0052] S231: When the calculated capacity of the expressway merging area does not meet the merging requirements of the main line and ramps, the maximum traffic flow allowed onto the expressway is controlled by releasing the traffic at the toll station entrance; then proceed to S2312;

[0053]

[0054] Where: q a ' ＝1 (k) is the maximum traffic flow allowed to enter the highway from the toll station entrance during the k-cycle period, pcu / s; δ x (k) is the proportion of people traveling on the merging area x entrance ramp in cycle k;

[0055] S232: Under the premise that the maximum traffic flow allowed to enter the highway is not less than the actual regulation rate, determine the regulation rate allowed in the direction of the toll station entrance and the maximum number of toll lanes allowed to be activated for each toll type; then proceed to S24;

[0056]

[0057] S24: Using the queue length outside the toll station entrance obtained by detector k5, calculate the traffic flow allowed to enter the toll station entrance from the connecting intersection under the queue length constraint; and enter the intersection signal control algorithm.

[0058]

[0059] Where: q a ″ ＝1 (k) is the traffic flow rate allowed to enter the outer square of the toll station entrance from the connecting intersection, pcu / s; τ a(k) is the queue length at the toll station in direction a during period k, pcu.

[0060] Furthermore, the intersection signal control algorithm specifically includes the following steps:

[0061] S31: Determine the flow restriction of the east entrance of the intersection;

[0062] S311: Using the queue length of the east entrance of the connecting intersection obtained by the detector k7, the minimum adjustment rate of the east entrance of the intersection under the queue length constraint is calculated; then the process proceeds to S312;

[0063]

[0064] Where: γ i,min (k) is the minimum adjustment rate of intersection entrance i under the queue length constraint within the k-cycle period, pcu / s; T I (k) is the control cycle length of the intersection within the k-cycle, s; τ i (k) is the queue length at intersection entrance i in period k, pcu; τ i,max is the maximum number of queued vehicles that can be accommodated at the intersection entrance i, pcu; ε i is the acceptable queue length reduction coefficient at intersection entrance i, 0≤ε i ≤1; i is the direction of the intersection entrance, i∈{1,2,3,4} represents the east, north, west and south entrances respectively;

[0065] S312: Taking into account the travel delays of drivers and passengers at toll booths and connecting intersections, determine the actual regulation rate at the east entrance of the intersection under the constraints of the maximum allowable flow rate and the minimum regulation rate, as shown in formula (4). Generally, a larger value helps to reduce delays. Go to S313;

[0066]

[0067] Where: γ i (k) is the regulation rate of intersection entrance i in period k, pcu / s;

[0068] S313: Calculate the flow of each turn at the east entrance of the intersection and give the capacity constraint; then proceed to S33;

[0069]

[0070] Where: q ij (k) is the traffic flow from import i to import j in period k, pcu / s; δ ij (k) is the flow rate ratio of inlet i to inlet j in cycle k; λ ij (k) is the green credit ratio of import i to import j in period k, C(k) is the intersection signal cycle duration in cycle k, s; n ij is the number of lanes from import i to j; s ij is the saturation flow rate of a single lane from entrance i to j, pcu / s; j is the intersection turn, j{l,s,r} represents left turn, straight ahead, and right turn, respectively;

[0071] S32: The sum of the traffic volume of all exit lanes turning into the east entrance at the intersection should not be greater than the traffic volume allowed to enter the outer square of the toll station entrance from the connecting intersection; turn into S33;

[0072] (q 2l (k)+q 3s (k)+q 4r (k))≤q′ a ′(k),a=2 (24) Where: q′ a ′(k) is the traffic flow in the square outside a in the direction of the toll station during period k, pcu / s;

[0073] S33: Under non-congested conditions, the intersection signal timing is carried out with the goal of minimizing the average delay of vehicles at the intersection; the intersection signal phase scheme is designed using the classic double-loop phase structure; it is determined whether the optimization model (25) has an optimal solution. If so, the linkage control strategy is adopted; if not, the process proceeds to S34;

[0074]

[0075] st

[0076]

[0077] Where: d ij (k) is the average delay of import vehicle i turning to vehicle j in cycle k, s; g ij (k) is the phase green light time of import i turning to j in cycle k, s; g min ,g max are the minimum and maximum green light duration, s; C min ,C max are the minimum and maximum signal cycle duration, s; Y max is the upper limit of saturation; I is the green light interval, s;

[0078] S34: Under congestion conditions, the intersection signal timing is performed with the goal of maximizing the number of vehicles passing through the intersection; and the linkage control strategy is switched;

[0079]

[0080] st

[0081]

[0082] Where: β is the intersection flow coefficient.

[0083] The beneficial effects of the present invention are that the present invention can be applied to scenarios where signal control is adopted at highway toll stations and connecting intersections, and can be used for refined intelligent coordinated linkage control of entrance ramps, toll stations and connecting intersections, thereby improving their overall traffic efficiency and ensuring their safe, efficient and smooth operation.

[0084] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0086] Figure 1 This is a schematic diagram of the structure of the linkage control system for the expressway entrance ramp, toll station and connecting intersection of the present invention;

[0087] Figure 2 The figure is a flow chart of the method for controlling the linkage of the entrance ramp, toll booth and connecting intersection of the expressway according to the present invention. DETAILED DESCRIPTION

[0088] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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 illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0089] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0090] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships 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 direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0091] See also Figures 1 and 2 The present invention provides a linkage control system for highway entrance ramps, toll stations and connecting intersections, as shown in Figure 1, the system includes an entrance ramp control module, a toll station discharge control module and a signal intersection control module.

[0092] The on-ramp control module is installed at the entrance ramp of a highway merging area, with two locations installed, corresponding to the number of merging areas. The two merging areas are numbered 1 and 2, and equipped with the following features: a ramp signal light is installed at the start of the acceleration lane, a ramp stop line is marked on the entrance ramp a certain distance upstream from the ramp signal light, and ramp vehicle detectors (k1 and k2) are installed. Mainline vehicle detectors (m1 and m2) are installed upstream of the mainline of the merging area.

[0093] The toll station discharge control module is installed at the toll station to control the number of active toll lanes of various types. The toll plaza on the highway side is called the inner plaza, and the one on the other side is called the outer plaza. Detectors K4 and K6 are installed at the inner and outer plazas, respectively, toward the toll station exit. Detectors K3 and K5 are installed at the inner and outer plazas, respectively, toward the toll station entrance, to collect traffic data from the inner and outer plazas.

[0094] The signalized intersection control module is installed at the intersection connecting to the toll booth and is used to control the release of turning vehicles at the intersection. Starting from the intersection entrance of the toll booth, the entrances are numbered counterclockwise as the east, north, west, and south entrances. Detectors k7, k8, k9, and k10 are installed in corresponding locations to collect traffic data from each entrance.

[0095] The linkage control method of the above system includes a vehicle exiting the highway control algorithm, a vehicle entering the highway control algorithm and an intersection signal control algorithm.

[0096] The vehicle exit control algorithm is linked to the toll station discharge control module. By adjusting the number of various types of toll lanes activated in the direction of the toll station exit, it can avoid congestion in the square in the direction of the toll station exit to the main line, affecting the main line vehicles from exiting the highway and causing driving safety hazards.

[0097] The vehicle entry control algorithm integrates the entry ramp control module and the toll station discharge control module. The entry ramp control module adjusts the timing and number of ramp vehicles merging into the main line based on the remaining capacity of the merging area and the acceptable ramp queue length to avoid traffic congestion in the merging area. If the entry ramp queue length exceeds the acceptable queue length, discharge control is implemented toward the toll station entrance to reduce traffic flow entering the highway from the toll station. At the toll station entrance, the toll station discharge control module adjusts the number of toll lanes of various types activated toward the toll station entrance to ensure that traffic flow entering the highway and the queue length outside the toll station entrance meet requirements, thereby preventing congestion from the entry ramp to the toll station or from the toll station entrance plaza to the connecting intersection.

[0098] The intersection signal control algorithm integrates the toll station discharge control module and the signalized intersection control module. In a non-congested state, signal timing is optimized to minimize average vehicle delay at the intersection. This is subject to the following constraints: The east entrance capacity must ensure that congestion queues at the east entrance do not extend to the toll station; The flow rate allowed into the east entrance exit lanes at each intersection must ensure that congestion queues in the plaza outside the toll station entrance do not extend to the connecting intersection. If the above intersection signal timing optimization model does not have an optimal solution, indicating that the intersection is congested, signal timing is optimized to maximize the number of vehicles passing through the intersection, while also meeting the above constraints.

[0099] Specifically,

[0100] 1) Vehicle high-speed control algorithm

[0101] 1.1) Using the traffic flow and queue length in the plaza at the toll station exit obtained by detector k4, the minimum regulation rate at the toll station exit under queue length constraints is calculated for each of the two toll types, ETC and MTC, as shown in equations (1) to (3). Proceed to 1.2).

[0102]

[0103]

[0104]

[0105] Where: γ ab,min (k) is the minimum adjustment rate of toll station direction a and toll type b under the queue length constraint within k cycles, pcu / s; δab (k) is the proportion of toll station direction a that chooses toll type b within period k; q a (k) is the traffic flow in direction a of the toll station during period k, pcu / s; T a (k) is the control cycle length of the toll station direction a within the k cycle, s; τ ab (k) is the queue length of toll station direction a and toll type b in period k, pcu; τ ab,max is the queue length threshold for toll station direction a and toll type b, pcu; τ a,max is the maximum number of queued vehicles that can be accommodated in the toll station direction a, pcu; ε a is the acceptable queue length reduction coefficient for the toll station direction a, 0≤ε a ≤1; a is the direction of the toll station, a∈{1,2} represents the exit and entrance respectively; b is the toll type, b∈{E,M} represents ETC and MTC respectively.

[0106] 1.2) Taking into account the operating costs of the toll station and the time costs of drivers and passengers, and subject to the constraints of the maximum number of enabled toll lanes and the minimum adjustment rate, determine the actual adjustment rates for the various toll lanes at the toll station exit, as shown in Equation (4). A larger actual adjustment rate results in higher operating costs for the toll station; a smaller actual adjustment rate results in higher time costs for drivers and passengers. Proceed to 1.3).

[0107]

[0108] Where: γ ab (k) is the actual adjustment rate of toll station direction a and toll type b in period k, pcu / s; μ ab is the service rate of a single lane of toll type b at toll station direction a, pcu / s; N ab The maximum number of toll lanes set for toll type b at toll station direction a.

[0109] 1.3) Under the premise that the traffic capacity is greater than the actual regulation rate, determine the minimum number of toll lanes required for each toll type at the toll station exit. Go to 3.1).

[0110]

[0111] Where: n ab (k) is the number of toll lanes enabled for toll type b in direction a of the toll station during cycle k.

[0112] 2) High-speed control algorithm on vehicles

[0113] 2.1) Entrance ramp control

[0114] 2.1.1) Using the mainline flow data obtained by the upstream mainline detectors m1 and m2 in the merging area, the on-ramp adjustment rate is calculated based on the remaining capacity of the expressway merging area, as shown in Equation (6). Proceed to 2.1.2).

[0115]

[0116] Where: γ x (k) is the ramp adjustment rate of the merging area x in period k, pcu / s; c x is the merging area x capacity, pcu / s; q mx (k) is the upstream flow rate of the main line of merging area x in period k, pcu / s; x is the merging area number, x∈{1,2} represents merging area 1 and merging area 2 respectively.

[0117] 2.1.2) Using the relationship between the ramp flow rate and the ramp regulation rate obtained by detectors k1 and k2, calculate the green light duration of the ramp signal, as shown in formula (7). Proceed to 2.1.3).

[0118]

[0119] Where: g x (k) is the duration of the green light of the ramp signal light in the merging area x in cycle k, s; C x (k) is the duration of the signal light cycle at the merging area x ramp within the k-cycle, s; s x is the saturation flow rate of the merging area x ramp, pcu / s; q x (k) is the ramp flow rate of the merging area x in period k, pcu / s.

[0120] 2.1.3) Calculate the minimum regulation rate for each on-ramp under the queue length constraint, as shown in Equation (8). Determine whether any on-ramp has a regulation rate less than the corresponding minimum regulation rate. If so, proceed to 2.3); if not, proceed to 2.2).

[0121]

[0122]

[0123] Where: γ x,min (k) is the minimum ramp adjustment rate of the merging area x under the queue length constraint within the k-cycle period, pcu / s; T x (k) is the control period length of the confluence area x within the k period, s; ​​τ x (k) is the ramp queue length of the merging area x in period k, pcu; τ x,max is the maximum number of queued vehicles that can be accommodated on the entrance ramp of the merging area x, pcu; ε xis the acceptable queue length reduction factor for the merging area x entrance ramp, 0≤ε x ≤1.

[0124] 2.2) Discharge control at toll station entrance.

[0125] 2.2.1) Using the data from detector k5 on the flow rate and queue length at the toll station entrance, the minimum regulation rate at the toll station entrance under the queue length constraint is calculated for both ETC and MTC toll types, as shown in formulas (10) to (12).

[0126] Go to 2.2.2).

[0127]

[0128]

[0129]

[0130] 2.2.2) Determine whether there is a specific toll type at the toll station entrance where the capacity is still less than the minimum adjustment rate even when all toll lanes are enabled. If so, set the allowable adjustment rate at the toll station entrance equal to the capacity and proceed to 2.4). If not, proceed to 2.2.3).

[0131]

[0132]

[0133] Where: γ a (k) is the permissible adjustment rate of the toll station direction a within the k cycle, pcu / s.

[0134] 2.2.3) Taking into account the operating costs of the toll station and the time costs of drivers and passengers, and subject to the constraints of the maximum number of enabled toll lanes and the minimum regulation rate, determine the actual regulation rates for the various toll lanes at the toll station entrance, as shown in Equation (15). Proceed to 2.2.4).

[0135]

[0136] 2.2.4) Under the premise that the traffic capacity is greater than the actual regulation rate, determine the minimum number of toll lanes required for each toll type at the toll station entrance. Go to 2.4).

[0137]

[0138]

[0139] 2.3) Correction of discharge control at toll station entrance.

[0140] 2.3.1) When the calculated capacity of the expressway merging area does not meet the merging requirements of the mainline and ramps, the maximum traffic flow allowed onto the expressway is controlled by releasing traffic at the toll station entrance. Proceed to 2.3.2).

[0141]

[0142] Where: q′ a＝1 (k) is the maximum traffic flow allowed to enter the highway from the toll station entrance during the k-cycle period, pcu / s; δ x (k) is the proportion of people choosing to drive on the merging area x entrance ramp in cycle k.

[0143] 2.3.2) Under the premise that the maximum traffic flow allowed on the highway is not less than the actual regulation rate, determine the permissible regulation rate at the toll station entrance and the maximum number of toll lanes permitted for each toll type. Proceed to 2.4).

[0144]

[0145] 2.4) Using the queue length at the toll station entrance obtained by detector k5, calculate the traffic flow allowed to enter the toll station entrance from the connecting intersection, subject to the queue length constraint. Go to 3.2).

[0146]

[0147] Where: q′ a ' ＝1 (k) is the traffic flow rate allowed to enter the outer square of the toll station entrance from the connecting intersection, pcu / s; τ a (k) is the queue length at the toll station in direction a during period k, pcu.

[0148] 3) Intersection signal control algorithm

[0149] 3.1) Determine the traffic flow constraints at the east entrance of the intersection.

[0150] 3.1.1) Using the queue length at the east entrance of the connecting intersection obtained by detector k7, calculate the minimum adjustment rate at the east entrance of the intersection under the queue length constraint. Proceed to 3.3.1.2.

[0151]

[0152] Where: γ i,min (k) is the minimum adjustment rate of intersection entrance i under the queue length constraint within the k-cycle period, pcu / s; T I (k) is the control cycle length of the intersection within the k-cycle, s; τ i(k) is the queue length at intersection entrance i in period k, pcu; τ i,max is the maximum number of queued vehicles that can be accommodated at the intersection entrance i, pcu; ε i is the acceptable queue length reduction coefficient at intersection entrance i, 0≤ε i ≤1; i is the direction of the intersection entrance, i∈{1,2,3,4} represents the east, north, west and south entrances respectively.

[0153] 3.1.2) Taking into account the travel delays of drivers and passengers at toll booths and connecting intersections, determine the actual regulation rate at the east entrance of the intersection, subject to the constraints of the maximum allowable flow rate and the minimum regulation rate, as shown in Equation (4). Generally, choosing a larger value helps reduce travel delays. Proceed to 3.1.3).

[0154]

[0155] 3.1.3) Calculate the flow rate at each turn at the east entrance of the intersection and assign capacity constraints. Proceed to 3.3).

[0156]

[0157] Where: q ij (k) is the traffic flow from import i to import j in period k, pcu / s; δ ij (k) is the flow rate ratio of inlet i to inlet j in period k; λ ij (k) is the green credit ratio of import i to import j in period k, g ij (k) is the phase green light time of the entrance i turning to j in the k cycle, s; C(k) is the intersection signal cycle length in the k cycle, s; n ij is the number of lanes from import i to j; s ij is the saturation flow rate of a single lane from entrance i to j, pcu / s; j is the intersection turn, and j{l,s,r} represents left turn, straight ahead, and right turn, respectively.

[0158] 3.2) The sum of the traffic volume in each exit lane of the intersection turning into the east entrance should not exceed the traffic volume allowed to enter the outer plaza of the toll station entrance from the connecting intersection. Proceed to 3.3).

[0159] (q 2l (k)+q 3s (k)+q 4r (k))≤q a ″(k),a=2 (24)

[0160] 3.3) Under non-congested conditions, intersection signal timing is performed with the goal of minimizing average vehicle delay at the intersection. A classic double-loop phase structure is used to design the intersection signal phase scheme. Determine whether the optimization model (25) has an optimal solution. If so, proceed to 4); if not, proceed to 3.4.

[0161]

[0162] st

[0163]

[0164] Where: d ij (k) is the average delay of import vehicle i turning to vehicle j in cycle k, s; g min ,g max are the minimum and maximum green light duration, s; C min ,C max are the minimum and maximum signal cycle duration, s; Y max is the upper limit of saturation; I is the green light interval, s.

[0165] 3.4) Under congestion conditions, adjust intersection signal timing to maximize the number of vehicles passing through the intersection. Proceed to 4).

[0166]

[0167] st

[0168]

[0169] Where: β is the intersection flow coefficient.

[0170] 4) Input the calculated results into the on-ramp control module, the toll station discharge control module, and the signalized intersection control module to implement the coordinated control strategy for the highway on-ramp, toll station, and connecting intersection. Update the traffic data obtained by the detector and proceed to 1).

[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A linkage control system for highway entrance ramps, toll booths and connecting intersections, characterized in that: The system includes an entrance ramp control module, a toll station discharge control module, and a signalized intersection control module; The entrance ramp control module is installed at the entrance ramp of the merging area of ​​the expressway, and two merging areas are installed according to the number of merging areas. The two merging areas are numbered I and II, and are equipped with the following supporting facilities: a ramp signal light is installed at the starting point of the acceleration lane, a ramp stop line is marked on the entrance ramp a certain distance upstream from the ramp signal light, and a ramp vehicle detector (k1, k2) is installed. A main line vehicle detector (m1, m2) is installed upstream of the main line of the merging area. The toll station discharge control module is installed at the toll station to control the number of toll lanes of various types at the toll station. The toll plaza on the side close to the highway is called the inner plaza, and the other side is called the outer plaza. Detectors K4 and K6 are installed at the inner plaza and outer plaza of the toll station exit respectively. Detectors K3 and K5 are installed at the inner plaza and outer plaza of the toll station entrance respectively to obtain traffic data of the inner and outer plazas of the toll station. The signalized intersection control module is set at the intersection where the toll station is connected, and is used to control the release of turning vehicles at the intersection; starting from the entrance road of the intersection connected to the toll station, the entrance roads are numbered as east, north, west and south entrances in a counterclockwise direction, and detectors k7, k8, k9 and k10 are respectively set correspondingly to obtain traffic data of each entrance road of the intersection; The system's linkage control method includes a vehicle disembarking high-speed control algorithm, a vehicle entering high-speed control algorithm, and an intersection signal control algorithm; The vehicle exit control algorithm is linked to the toll station discharge control module to adjust the number of toll lanes of various types enabled at the toll station exit, specifically including the following steps: S11: Using the square flow rate and queue length in the toll station exit direction obtained by detector k4, the minimum regulation rate in the toll station exit direction under the queue length constraint is calculated for the two charging types of ETC and MTC, as shown in formulas (1) to (3); then proceed to S12; (1) (2) (3) Where: for Toll booth direction under queue length constraint within the cycle Charge Type Minimum regulation rate; for Toll station direction within the cycle Select the fee type proportion; for Toll station direction within the cycle Traffic flow; for Toll station direction within the cycle The length of the control cycle; for Toll station direction within the cycle Charge Type The queue length; To the toll booth Charge Type The queue length threshold; To the toll booth The maximum number of queued vehicles that can be accommodated; To the toll booth Acceptable queue length reduction factor, ; To the toll booth direction. Respectively represent the exit and entrance; For the charging type, Respectively represent ETC and MTC; S12: Taking into account the operating cost of the toll station and the time cost of drivers and passengers, under the constraints of the maximum number of toll lanes that can be enabled and the minimum adjustment rate, determine the actual adjustment rate of various toll lanes in the exit direction of the toll station, as shown in formula (4); the larger the actual adjustment rate value, the higher the operating cost of the toll station; the smaller the actual adjustment rate value, the higher the time cost of drivers and passengers; then proceed to S13; (4) Where: for Toll station direction within the cycle Charge Type The actual regulation rate; To the toll booth Charge Type Single lane service rate; To the toll booth Charge Type The maximum number of toll lanes set; S13: Under the premise that the traffic capacity is greater than the actual regulation rate, determine the minimum number of toll lanes required to be activated for each toll type at the toll station exit; then proceed to the intersection signal control algorithm; (5) Where: for Toll station direction within the cycle Charge Type The number of enabled toll lanes.

2. The linkage control system according to claim 1, characterized in that: The vehicle access control algorithm links the entrance ramp control module and the toll station discharge control module; the entrance ramp control module adjusts the timing and number of ramp vehicles merging into the main line based on the remaining traffic capacity of the merging area and the acceptable queue length of the ramp to avoid traffic congestion in the merging area; if the queue length of the entrance ramp exceeds the acceptable queue length, the toll station entrance direction discharge control is implemented to reduce the traffic flow entering the highway from the toll station; at the toll station entrance direction, the toll station discharge control module adjusts the number of various types of toll lanes activated in the toll station entrance direction to ensure that the traffic flow entering the highway and the queue length in the square outside the toll station entrance direction meet the requirements, thereby avoiding congestion of the entrance ramp queue at the toll station or congestion of the queue in the square outside the toll station entrance direction at the connecting intersection; The intersection signal control algorithm links the toll station discharge control module and the signal intersection control module; in a non-congested state, signal timing is performed with the goal of minimizing the average delay per vehicle at the intersection; at the same time, the following constraints must be met: the traffic capacity of the east entrance must ensure that the congestion queue at the east entrance does not extend to the toll station; the flow rate allowed to enter the lanes on the exit side of the east entrance at each turn of the intersection must ensure that the congestion queue outside the square in the direction of the toll station entrance will not extend to the connecting intersection; if the above intersection signal timing optimization model does not have an optimal solution, it means that the intersection is in a congested state, so signal timing is performed with the goal of maximizing the number of vehicles passing through the intersection, and the above constraints must also be met.

3. The linkage control system according to claim 2, characterized in that: The vehicle high-speed control algorithm specifically includes the following steps: S21: On-ramp control; S211: Calculate the entrance ramp adjustment rate based on the remaining traffic capacity of the expressway merging area using the mainline flow obtained by the mainline detectors m1 and m2 upstream of the merging area, as shown in formula (6); then proceed to S212; (6) Where: for Confluence area within the cycle The entrance ramp adjustment rate; For the confluence area traffic capacity; for Confluence area within the cycle Mainline upstream flow; Number the confluence area. They represent confluence area 1 and confluence area 2 respectively; S212: Calculate the green light duration of the ramp signal light using the relationship between the ramp flow rate and the ramp regulation rate obtained by detectors k1 and k2, as shown in formula (7); then proceed to S213; (7) Where: for Confluence area within the cycle The duration of the green light on the ramp signal light; for Confluence area within the cycle Ramp signal cycle duration; For the confluence area Ramp saturation flow rate; for Confluence area within the cycle Ramp flow; S213: Calculate the minimum regulation rate of each entrance ramp under the queue length constraint, as shown in formula (8); determine whether there is an entrance ramp whose regulation rate is less than the corresponding minimum regulation rate; if so, go to S23; if not, go to S22; (8) (9) Where: for Merging area under queue length constraint within a period The minimum regulation rate of the entrance ramp; for Confluence area within the cycle The length of the control cycle; for Confluence area within the cycle Ramp queue length; For the confluence area The maximum number of queued vehicles that the entrance ramp can accommodate; For the confluence area Acceptable queue length reduction factor for entrance ramps, ; S22: discharge control at the toll station entrance; S221: Using the flow rate and queue length outside the toll station entrance direction obtained by detector k5, the minimum regulation rate of the toll station entrance direction under the queue length constraint is calculated for the two charging types of ETC and MTC, as shown in formulas (10) to (12); then proceed to S222; (10) (11) (12) S222: Determine whether there is a certain toll type in the toll station entrance direction where the traffic capacity is still less than the minimum adjustment rate even when all toll lanes are activated; if so, set the allowed adjustment rate in the toll station entrance direction equal to the traffic capacity and proceed to S24; if not, proceed to S223; (13) (14) Where: for Toll station direction within the cycle The allowable regulation rate; S223: Taking into account the operating costs of the toll station and the time costs of drivers and passengers, under the constraints of the maximum number of toll lanes that can be activated and the minimum adjustment rate, the actual adjustment rates of various toll lanes in the direction of the toll station entrance are determined, as shown in formula (15); then proceed to S224; (15) S224: Under the premise that the traffic capacity is greater than the actual regulation rate, determine the minimum number of toll lanes that need to be activated for various toll types in the toll station entrance direction; then proceed to S24; (16) (17) S23: Modification of discharge control at toll station entrance; S231: When the calculated capacity of the expressway merging area does not meet the merging requirements of the main line and ramps, the maximum traffic flow allowed onto the expressway is controlled by releasing the traffic at the toll station entrance; then proceed to S2312; (18) Where: for Toll station direction within the cycle a The maximum traffic volume allowed on the highway; for Select the confluence area within the cycle proportion of on-ramp travel; S232: Under the premise that the maximum traffic flow allowed to enter the highway is not less than the actual regulation rate, determine the regulation rate allowed in the direction of the toll station entrance and the maximum number of toll lanes allowed to be activated for each toll type; then proceed to S24; (19) S24: Using the queue length outside the toll station entrance obtained by detector k5, calculate the traffic flow allowed to enter the toll station entrance from the connecting intersection under the queue length constraint; then proceed to the intersection signal control algorithm; (20) Where: for k Toll station direction within the cycle a Traffic flow from the connecting intersection to the outer square towards the toll station entrance is allowed; for Toll station direction within the cycle The queue length.

4. The linkage control system according to claim 3, characterized in that: The intersection signal control algorithm specifically includes the following steps: S31: Determine the flow restriction of the east entrance of the intersection; S311: Using the queue length of the east entrance of the connecting intersection obtained by the detector k7, the minimum adjustment rate of the east entrance of the intersection under the queue length constraint is calculated; then the process proceeds to S312; (21) Where: for Intersection entrance under queue length constraint within cycle Minimum regulation rate; for The length of the control cycle of the intersection within the cycle; for Intersection entrance within the cycle The queue length; For intersection entrance The maximum number of queued vehicles that can be accommodated; For intersection entrance Acceptable queue length reduction factor, ; The direction of the intersection entrance road, They represent east, north, west, and south imports respectively; S312: Taking into account the travel delays of drivers and passengers at the toll station and the connecting intersection, under the constraints of the maximum allowable flow rate and the minimum regulation rate, determine the actual regulation rate of the east entrance of the intersection, as shown in formula (4); then proceed to S313; (22) Where: for Intersection entrance within the cycle The regulation rate; S313: Calculate the flow of each turn at the east entrance of the intersection and give the capacity constraint; then proceed to S33; (23) Where: for Imports during the cycle Steering Traffic flow; for Imports during the cycle Steering Traffic ratio; for Imports during the cycle Steering Green letter ratio, ; for The duration of the intersection signal cycle within the cycle; For import Steering Number of driving lanes; For import Steering Single lane saturation flow rate; Turning at an intersection, They represent left turn, straight ahead and right turn respectively; S32: The sum of the traffic volume of all exit lanes turning into the east entrance at the intersection should not be greater than the traffic volume allowed to enter the outer square of the toll station entrance from the connecting intersection; turn into S33; (24) S33: Under non-congested conditions, the intersection signal timing is carried out with the goal of minimizing the average delay of vehicles at the intersection; the intersection signal phase scheme is designed using the classic double-loop phase structure; it is determined whether the optimization model (25) has an optimal solution. If so, the linkage control strategy is adopted; if not, the process proceeds to S34; (25) Where: for Imports during the cycle Steering All vehicles are delayed; for Imports during the cycle Steering Phase green light time; They are the minimum and maximum green light duration respectively; They are the minimum and maximum values ​​of the signal cycle duration respectively; is the upper limit of saturation; Green light interval time; S34: Under congestion conditions, the intersection signal timing is performed with the goal of maximizing the number of vehicles passing through the intersection; and the linkage control strategy is switched; (26) Where: is the intersection flow coefficient.

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