A mixed traffic flow control method, device, equipment and storage medium

Abstract

The application discloses a mixed traffic flow control method, device and equipment and a storage medium. The method comprises the following steps: determining a first relationship in a preset offline control period according to the traffic flow of each road section in a target road network, the passing time of each road section and the non-admission traffic flow matched by each start-stop point combination; determining the target value of the traffic flow of each road section when the first relationship satisfies a first constraint condition; wherein the first constraint condition comprises a flow distribution constraint, a first road capacity constraint, a signal lamp time constraint, a signal lamp phase difference constraint, a road section passing time constraint and a first relationship value constraint; and determining the green light on duration of each road section signal lamp according to the target value of the traffic flow of each road section, so as to realize the mixed traffic flow control in the target road network. The technical scheme solves the problem that the over-saturation phenomenon of the mixed traffic flow is difficult to effectively eliminate, and can greatly reduce the passing cost while improving the signal control coordination of the road network.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of traffic control, and in particular to a mixed traffic flow control method, device, equipment and storage medium. BACKGROUND

[0002] With the rapid increase of urban residents' travel demand, traffic congestion frequently occurs in cities at all levels, causing huge economic losses. As a simple means of urban intersection traffic management, signal control has been widely used worldwide. In order to realize the orderly organization of intersection, the signal control platform divides different traffic flows into a series of conflict-free phases, and assigns the traffic right of intersection to each phase in turn. When the traffic demand exceeds the capacity of the road network and traffic overflow occurs, the traffic will enter the oversaturated state. In the oversaturated state, the traffic flow cannot dissipate within the green light time, and the signal control strategy will fail.

[0003] At present, the main way to eliminate oversaturation is through coordinated signal control strategy. However, due to the complexity of traffic state description and control strategy optimization, the existing coordinated signal control strategy is usually designed for the main road in the road network, which is difficult to effectively eliminate the oversaturation phenomenon and cannot realize the overall coordinated signal control of the system. SUMMARY

[0004] The present application provides a mixed traffic flow control method, device, equipment and storage medium to solve the problem that the oversaturation phenomenon of mixed traffic flow is difficult to effectively eliminate, which can improve the coordination of road network signal control while greatly reducing the travel cost.

[0005] According to one aspect of the present application, a mixed traffic flow control method is provided, the method comprising:

[0006] determining a first relationship in a preset offline control period according to the traffic flow of each road segment in the target road network, the travel time of each road segment, and the non-admission traffic flow matched by each start-end point combination; wherein the start-end point combination is determined based on the entrance and exit of the target road network; and the road segment includes intersection road segment, connection road segment, entrance road segment and exit road segment;

[0007] determining the target value of the traffic flow of each road segment when the first relationship satisfies a first constraint condition; wherein the first constraint condition includes flow allocation constraint, first road capacity constraint, signal light time constraint, signal light phase difference constraint, road travel time constraint and first relationship value constraint;

[0008] determining the green light duration of the signal light of each road segment according to the target value of the traffic flow of each road segment, so as to realize the control of mixed traffic flow in the target road network.

[0009] According to another aspect of the present application, there is provided a control device for mixed traffic flow, comprising:

[0010] a first relationship determining module configured to determine a first relationship in a preset off-line control period according to traffic flow of each road segment in a target road network, travel time of each road segment, and non-admission traffic flow matched with each origin-destination combination, wherein the origin-destination combination is determined based on entries and exits of the target road network, and the road segment includes intersection road segment, connection road segment, entry road segment, and exit road segment;

[0011] a target value determining module configured to determine target values of traffic flow of each road segment when the first relationship satisfies a first constraint condition, wherein the first constraint condition includes flow distribution constraint, first road capacity constraint, signal time constraint, signal phase difference constraint, road travel time constraint, and first relationship value constraint;

[0012] a traffic flow control module configured to determine green light on duration of a signal of each road segment according to the target values of traffic flow of each road segment, so as to realize mixed traffic flow control in the target road network.

[0013] According to another aspect of the present application, there is provided an electronic device, comprising:

[0014] at least one processor; and

[0015] a memory connected with the at least one processor; wherein

[0016] the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the control method for mixed traffic flow according to any one of the embodiments of the present application.

[0017] According to another aspect of the present application, there is provided a computer readable storage medium storing computer instructions for enabling a processor to execute the control method for mixed traffic flow according to any one of the embodiments of the present application when executed by the processor.

[0018] The technical scheme of the embodiment of the application is as follows: according to the traffic flow of each road section in the target road network, the passing time of each road section, and the non-admission traffic flow matched by each start-stop point combination, a first relationship is determined within a preset off-line control period; then when the first relationship satisfies a first constraint condition, a target value of the traffic flow of each road section is determined; wherein the first constraint condition comprises a flow distribution constraint, a first road capacity constraint, a signal lamp time constraint, a signal lamp phase difference constraint, a road section passing time constraint, and a first relationship value constraint; according to the target value of the traffic flow of each road section, the green light on duration of the signal lamp of each road section is determined, so as to realize the mixed traffic flow control in the target road network. The scheme takes the whole target road network as an object to design a coordinated signal control strategy, solves the problem that the over-saturation phenomenon of the mixed traffic flow is difficult to eliminate effectively, and can greatly reduce the passing cost while improving the coordination of the road network signal control.

[0019] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1A is a flow chart of a mixed traffic flow control method according to the first embodiment of the application;

[0022] Figure 1B is a schematic diagram of a target road network according to the embodiment of the application;

[0023] Figure 1C is a start-stop point combination distribution schematic diagram of a target road network according to the embodiment of the application;

[0024] Figure 1D is a schematic diagram of intersection node division according to the embodiment of the application;

[0025] Figure 1E is a schematic diagram of a connected road section according to the embodiment of the application;

[0026] Figure 1F is a phase design schematic diagram according to the embodiment of the application;

[0027] Figure 2 is a flow chart of a mixed traffic flow control method according to the second embodiment of the application;

[0028] Figure 3 This is a schematic diagram of the structure of a control device for mixed traffic flow provided in Embodiment 3 of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of an electronic device that implements the control method for mixed traffic flow according to an embodiment of the present invention. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices. The acquisition, storage, use, and processing of data in the technical solutions of this application all comply with the relevant provisions of national laws and regulations.

[0032] Example 1

[0033] Figure 1A This is a flowchart illustrating a mixed traffic flow control method provided in Embodiment 1 of the present invention. This embodiment is applicable to mixed traffic flow control scenarios in road networks. The method can be executed by a mixed traffic flow control device, which can be implemented in hardware and / or software and can be configured in an electronic device. Figure 1A As shown, the method includes:

[0034] S110. Based on the traffic flow of each road segment in the target road network, the travel time of each road segment, and the non-accessible traffic flow matched by each start-end point combination, determine the first relationship within the preset offline control period; wherein, the start-end point combination is determined based on the entrance and exit of the target road network; the road segment includes intersection road segment, connecting road segment, entrance road segment, and exit road segment.

[0035] The scheme can be executed by a traffic control platform, which can control signals inside and at the boundary of a target road network, thereby achieving effective mixed traffic flow management. The mixed traffic flow can include autonomous vehicles and manually driven vehicles. Figure 1B is a schematic diagram of a target road network according to an embodiment of the present application. As shown in Figure 1B , the shaded area can represent an internal area of the target road network, and the area where the entrances and exits of the target road network are located can be a boundary area of the road network. The dots represent intersections of the target road network, and the arrows represent passable directions of road segments.

[0036] In order to finely analyze the target road network, the traffic control platform can mark each intersection of the target road network and set multiple groups of start and end point combinations. The start and end point combinations can be determined according to the entrances and exits of the target road network. Figure 1C is a schematic diagram of start and end point combinations of a target road network according to an embodiment of the present application, as shown in Figure 1C , each intersection is marked with a number, and O-D pairs represent start and end point combinations of the target road network, where O represents the starting point of the mixed traffic flow entering the target road network, D represents the terminal point of the mixed traffic flow exiting the target road network, and O and D with the same number subscript represent a start and end point combination. It should be noted that the traffic control platform can set start and end point combinations according to actual needs of the target road network, or can determine start and end point combinations by arranging and combining all entrances and exits in the target road network.

[0037] The traffic control platform can take the entrances in the target road network as entrance nodes and the exits as exit nodes. The set of entrance nodes of the target road network is represented as The set of exit nodes is represented as In order to represent the conflict relationship of the mixed traffic flow at the intersection, the traffic control platform can also set separation nodes and merging nodes. The separation nodes represent the positions where the mixed traffic flow separates into different passable directions, including straight, left turn and right turn. The merging nodes represent the positions where the mixed traffic flow from different passable directions converges. Figure 1D is a schematic diagram of intersection node division according to an embodiment of the present application, taking Figure 1D a two-way six-lane intersection as an example, there are 12 separation nodes and 12 merging nodes at the intersection. The traffic control platform can unify the separation nodes and the merging nodes into intersection nodes, represented as , to represent the set of intersection nodes.

[0038] The traffic control platform can abstract the target road network into a directed graph structure, represented as , where represents the set of road segments, a set of nodes, According to the node types of the start and end points of the road segment, the traffic control platform can divide the road segment types into intersection road segments, connection road segments, entry road segments and exit road segments. It is easy to understand that the end point of the entry road segment is an entry node and the start point is a separation node; the end point of the exit road segment is a merging node and the start point is an exit node. As shown in Figure 1D the end point of the intersection road segment is a separation node and the start point is a merging node of the same intersection. Figure 1E is a schematic diagram of a connection road segment provided by an embodiment of the present application, as shown in Figure 1E the end point of the connection road segment is a merging node and the start point is a separation node of an adjacent intersection. The intersection road segment set of the target road network is represented as The connection road segment set is represented as The entry road segment set is represented as The exit road segment set is represented as The traffic control platform can represent the road segment set other than the intersection road segment as The traffic control platform can represent the intersection as n and the intersection set as

[0039] For the target road network, the mixed traffic flow of the intersection is controlled by the traffic light. In order to realize the coordination of the control between intersections, the traffic control platform sets an offline control period to realize the signal control of each intersection in the target road. At the same time, the traffic control platform sets a fixed timing signal control strategy for each intersection according to the offline control period. In order to ensure that the mixed traffic flow of each traffic direction has no conflict, the traffic control platform needs to set at least four phases to allocate the right of way of the intersection to the conflicting flow. Figure 1F is a schematic diagram of phase design provided by an embodiment of the present application, and the four phases can include phase 1, phase 2, phase 3 and phase 4 as shown in Figure 1F It is worth noting that the traffic control platform does not consider the right turn traffic flow in the phase design because the right turn traffic flow does not have a conflict relationship with the traffic flow of other traffic directions. Therefore, in each phase, the mixed traffic flow of two traffic directions can have the right of way at the same time.

[0040] According to the traffic flow of each road segment, the travel time of each road segment and the non-admission traffic flow matched by each start and end point combination in the target road network, the traffic control platform can determine a first relationship in the offline control period. The offline control period can be a relatively long period of time, such as one day, six hours, etc. The first relationship can represent the total travel cost of all vehicles in the target road network.

[0041] S120, determining a target value of the traffic flow of each road segment when the first relationship satisfies a first constraint condition; wherein the first constraint condition comprises a flow distribution constraint, a first road capacity constraint, a signal light time constraint, a signal light phase difference constraint, a road segment travel time constraint, and a first relationship value constraint.

[0042] The traffic control platform can determine a target value of the traffic flow of each road segment when the first relationship satisfies a first constraint condition. The first constraint condition can include a flow distribution constraint, a first road capacity constraint, a signal light time constraint, a signal light phase difference constraint, a road segment travel time constraint, and a first relationship value constraint. The flow distribution constraint can be a constraint determined by distributing the mixed traffic flow entering the target road network, the first road capacity constraint can be a constraint determined based on the lane capacity in the target road network, the signal light time constraint can be a constraint on the length of time that a signal light is on in the target road network, the signal light phase difference constraint can be a constraint on the phase relationship of the signal lights in the target road network, and the road segment travel time constraint can be a constraint on the travel time of each road segment in the target road network.

[0043] S130, determining the length of time that a green light of each signal light is on based on the target value of the traffic flow of each road segment to achieve mixed traffic flow control in the target road network.

[0044] The traffic control platform can determine one or more calculation results of the first relationship based on the flow distribution constraint, the first road capacity constraint, the signal light time constraint, the signal light phase difference constraint, and the road segment travel time constraint. The calculation results can represent the total travel cost of all vehicles in the target road network. The traffic control platform can sort the calculation results and determine the target value of the traffic flow of each road segment based on the first relationship value constraint. The first relationship value constraint can be to take the minimum value of the calculation results. Based on the target value of the traffic flow of each road segment, the traffic control platform can determine the length of time that a green light of each road segment is on based on the relationship between the traffic flow of each road segment and the length of time that a signal light is on in the first road capacity constraint to achieve mixed traffic flow control in the target road network.

[0045] The technical solution determines a first relationship in a preset off-line control period according to traffic flow of each road section in a target road network, passing time of each road section and non-admission traffic flow matched by each start-end point combination; then, when the first relationship satisfies a first constraint condition, target values of the traffic flow of each road section are determined; wherein the first constraint condition includes flow distribution constraint, first road capacity constraint, signal lamp time constraint, signal lamp phase difference constraint, road section passing time constraint and first relationship value constraint; according to the target values of the traffic flow of each road section, the green light on duration of the signal lamp of each road section is determined to realize mixed traffic flow control in the target road network. The scheme solves the problem that the over-saturation phenomenon of mixed traffic flow is difficult to effectively eliminate by taking the whole target road network as an object to design a coordinated signal control strategy, and can greatly reduce the passing cost while improving the signal control coordination of the road network.

[0046] Embodiment two

[0047] Figure 2 A flow chart of a mixed traffic flow control method provided for the second embodiment of the application is shown in the figure, and the embodiment is refined based on the above-mentioned embodiment. As shown in the figure, the method comprises the following steps. Figure 2

[0048] S210, a first relationship in a preset off-line control period is determined according to traffic flow of each road section in a target road network, passing time of each road section and non-admission traffic flow matched by each start-end point combination; wherein the start-end point combination is determined based on the entrance and exit of the target road network; and the road section includes intersection road section, connecting road section, entrance road section and exit road section.

[0049] In a specific scheme, the first relationship can be expressed as wherein ij represents a road section with node i as the start point and node j as the end point, represents a road section set, π ij represents traffic flow of the road section ij, t ij represents passing time on the road section ij, w represents start-end point combination index, represents a start-end point combination set, represents non-admission traffic flow matched by the start-end point combination w, T H represents an off-line control period; it can be understood that, represents total passing time of vehicles entering the target road network, represents total waiting time of vehicles not entering the target road network at the entrance.

[0050] ​The scheme adds the time cost of the vehicle entering the target road network and the time cost of the vehicle not entering the target road network as a first relationship, and is beneficial to design the optimal signal control strategy according to the overall traffic cost of the target road network.

[0051] In the first relationship, when the first constraint condition is satisfied, the target value of the traffic flow of each road section is determined; wherein the first constraint condition includes a flow distribution constraint, a first road capacity constraint, a signal lamp time constraint, a signal lamp phase difference constraint, a road section travel time constraint and a first relationship value constraint.

[0052] The traffic control platform can determine the target value of the traffic flow of each road section when the first relationship satisfies the first constraint condition. ij In the scheme, optionally, the flow distribution constraint includes:

[0053]

[0054]

[0055]

[0056]

[0057] Wherein, w represents the start and end point combination index, represents the start and end point combination set, d w represents the admitted traffic flow matched with the start and end point combination w, represents the non-admitted traffic flow matched with the start and end point combination w, r represents the path index in the start and end point combination w, represents the path set in the start and end point combination w, represents the feasible path set of all start and end point combinations, f r represents the traffic flow on the path r in the start and end point combination, ij represents the road section with the starting node i and the ending node j, represents the road section set, represents the association relationship between the road section ij and the path r, π ij represents the traffic flow of the road section ij.

[0058] The scheme refines the flow constraint of the target road network according to the start and end point combination and the road section, which is beneficial to realize the refined road network research, and further determine the signal control strategy more suitable for the actual situation of the road network.

[0059] ​It is easy to understand that the traffic flow allocated to each road segment cannot exceed the maximum capacity of the road segment, and the mixed traffic flow on each road segment within the intersection is controlled by the signal light, that is, the traffic flow that can be dissipated in each signal control period is determined by the green light duration. Compared with the offline control period, the signal control period can be a smaller time period, such as 60 seconds, 120 seconds, etc. In order to achieve good mixed traffic flow control, the offline control period T H may be an integer multiple of the signal control period T C .

[0060] It should be noted that on each road segment, the lane capacity is highly related to the minimum headway between vehicles in the following mode. In the mixed traffic flow composed of autonomous vehicles and manually driven vehicles, there are four vehicle following modes: (1) autonomous vehicle following autonomous vehicle, (2) autonomous vehicle following manually driven vehicle, (3) manually driven vehicle following autonomous vehicle, and (4) manually driven vehicle following manually driven vehicle.

[0061] For mode (1), the following autonomous vehicle can communicate with the front vehicle, so the headway between the two vehicles can be small. For mode (2), the following autonomous vehicle cannot communicate with the front vehicle, and can obtain distance, speed, etc. information through sensing devices, and then obtain the distance interval and speed difference between the two vehicles, so the headway between the two vehicles can be larger than that in mode (1). In modes (3) and (4), for manually driven vehicles, the type of the vehicle in front has no obvious effect on the following mode, so the headway can be equal.

[0062] The headway of mode (1) can be represented as h AA , the headway of mode (2) can be represented as h AH , and the headway of modes (3) and (4) can be represented as h HX . The traffic occupancy rate of autonomous vehicles is represented as P CAV , and the occurrence probabilities of the above three following modes can be represented as:

[0063]

[0064]

[0065]

[0066] wherein, represents the occurrence probability of mode (1), represents the occurrence probability of mode (2), represents the occurrence probability of modes (3) and (4). The average headway of the mixed traffic flow can be represented as:

[0067] Thus, the first road capacity constraint can include:

[0068]

[0069]

[0070] wherein β∈(0,1) represents a buffer parameter, represents a set of entry nodes, represents a set of exit nodes, represents a set of intersections, represents a set of road segments between node n1 and node n2 outside the intersection, ij represents a road segment with the starting point of the road segment being node i and the ending point of the road segment being node j, π ij represents the traffic flow of road segment ij, represents the number of lanes of road segment between node n1 and node n2, h f represents the average headway of mixed traffic flow, T C represents the signal control cycle of the signal light, g ij represents the green time of road segment ij, represents a set of intersection road segments, L ij represents the number of lanes of intersection road segment ij.

[0071] The above scheme performs road capacity constraints on intersection road segments and non-intersection road segments respectively according to the characteristics of road segments, which is conducive to realizing fine description of the target road network and ensuring the stability of the signal control strategy

[0072] It can be understood that, taking the example of setting four traffic phases for each intersection, the traffic control center can allocate the traffic right to the four phases in turn to ensure the conflict-free of vehicle traffic. Therefore, the signal light time constraint can include:

[0073]

[0074]

[0075] The signal light phase difference constraint includes:

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] wherein, denotes a set of intersections, n denotes an intersection index, m denotes a phase index, phase 1 denotes a first pair of left-turn phases, phase 2 denotes a first pair of straight phases, phase 3 denotes a second pair of left-turn phases, phase 4 denotes a second pair of straight phases, denotes a green time of intersection n phase m, G min denotes a minimum green time, G max denotes a maximum green time, g ij denotes a green time on link ij, denotes a set of mixed traffic flow directions of intersection n phase m, T C denotes a signal control cycle of a signal light, denotes a phase difference of intersection n phase m, θ i denotes a phase difference of node i, denotes a periodicity description parameter of signal control,

[0084] For different types of links, the traffic control platform can set link travel time constraints respectively. Specifically, the link travel time constraints can include intersection link constraints, connection link constraints, exit link constraints, and entrance link constraints; the intersection link, connection link, exit link, and entrance link are determined based on the node type of the link start point and the link end point; the node type includes a split node, a merge node, an entrance node, and an exit node. The intersection link constraint includes:

[0085]

[0086]

[0087]

[0088] wherein, denotes a set of intersection links, t ij denotes a travel time on link ij with node i as the link start point and node j as the link end point, denotes a travel time on link ij at the maximum speed, θ i denotes a phase difference of node i, determined according to the current phase of node i, θ j denotes a phase difference of node j, determined according to the current phase of node j, TC denotes the signal control period of the signal light, a ij denotes a periodicity description parameter of the phase difference.

[0089] Since the vehicle's passing at the intersection is controlled by the signal light, there is a case that the vehicle stops and waits for the green light time before entering the intersection. Therefore, the traffic control platform can represent the vehicle delay caused by the signal light in the passing time of the corresponding connecting road segment. Specifically, for the connecting road segment ij, the passing time of the vehicle includes the total time from when the vehicle leaves the merging node i to when the vehicle enters the intersection through the separation node j. The connecting road segment constraint can include:

[0090]

[0091]

[0092] wherein, denotes the set of connecting road segments.

[0093] For the exit road segment, since the vehicle's leaving is not limited by the signal control, the exit road segment constraint can include: wherein, denotes the set of exit road segments.

[0094] For the entry road segment, the arriving vehicles are continuous and stable, and thus the average waiting time of the vehicle on the entry road segment is half of the signal control period, i.e. The entry road segment constraint can include: wherein, denotes the set of entry road segments.

[0095] The scheme sets the passing time constraints for the intersection road segment, the connecting road segment, the exit road segment, and the entry road segment respectively, which improves the reliability of the signal control strategy.

[0096] S230, according to the target value of the traffic flow of each road segment, determining the length of the green light of each road segment signal light to realize the mixed traffic flow control in the target road network.

[0097] Since p in the first relationship is ij ×t ij a nonlinear term, the traffic control platform can solve the first relationship and the first constraint condition as a mixed integer nonlinear programming (MINLP) problem. According to the target value of the traffic flow of each road segment Relationship between road segment traffic flow and green light length in first road capacity constraint The traffic control platform can determine the green light duration of each road segment

[0098] The traffic control platform can control the mixed traffic flow in the target road network according to the green light duration of each road segment.

[0099] S240, when the second relationship satisfies the second constraint condition, determining the green light duration of each entry signal light in the target road network in the preset online control period to realize the access control of the mixed traffic flow.

[0100] After determining the signal light duration of each road segment in the target road network, the traffic control platform can obtain the green light duration of each road segment in the current offline control period, and determine the green light duration of the associated road segment signal light of the upstream and downstream connected road segments in the green light duration of each road segment.

[0101] According to the traffic flow of the upstream and downstream connected road segments in the last online control period, the green light duration of the associated road segment signal light of the upstream and downstream connected road segments, the number of lanes of the upstream and downstream connected road segments, the average headway of the mixed traffic flow, and the traffic capacity of the upstream and downstream connected road segments, the traffic flow prediction result of the current online control period is determined. According to the traffic flow prediction result, the traffic control platform can determine the second road capacity constraint. The traffic control platform can obtain the traffic demand at the entrance in advance, and determine the entry flow limit constraint according to the traffic flow entering the target road network through the entrance cannot exceed the entry traffic demand. According to the second road capacity constraint, the entry flow limit constraint and the second relationship constraint, the traffic control platform can determine the green light duration of each entry signal light in the target road network in the current online control period.

[0102] The second relationship is determined according to the cumulative length of each entry vehicle in the target road network and the vehicle retention flow in the online control period. The second relationship can represent the total travel cost of the vehicle entering the target road network and not passing through the path in each online control period.

[0103] The technical scheme determines a first relationship in a preset off-line control period according to traffic flow of each road section in a target road network, passing time of each road section and non-admission traffic flow matched by each start-stop point combination; then, when the first relationship satisfies a first constraint condition, target values of the traffic flow of each road section are determined; wherein the first constraint condition includes a flow distribution constraint, a first road capacity constraint, a signal lamp time constraint, a signal lamp phase difference constraint, a road section passing time constraint and a first relationship value constraint; according to the target values of the traffic flow of each road section, the green light on duration of the signal lamp of each road section is determined, so as to realize mixed traffic flow control in the target road network. The scheme takes the whole target road network as an object to design a coordinated signal control strategy, solves the problem that the over-saturation phenomenon of mixed traffic flow is difficult to eliminate effectively, and can greatly reduce the passing cost while improving the coordination of road network signal control.

[0104] Embodiment three

[0105] Figure 3 A structure schematic diagram of a mixed traffic flow control device provided for the embodiment three of the application is shown in the figure. Figure 3 The device includes:

[0106] A first relationship determination module 310 is configured to determine a first relationship in a preset off-line control period according to traffic flow of each road section in a target road network, passing time of each road section and non-admission traffic flow matched by each start-stop point combination; wherein the start-stop point combination is determined based on the entrance and exit of the target road network; and the road section includes an intersection road section, a connecting road section, an entrance road section and an exit road section.

[0107] A target value determination module 320 is configured to determine target values of the traffic flow of each road section when the first relationship satisfies a first constraint condition; wherein the first constraint condition includes a flow distribution constraint, a first road capacity constraint, a signal lamp time constraint, a signal lamp phase difference constraint, a road section passing time constraint and a first relationship value constraint.

[0108] A traffic flow control module 330 is configured to determine the green light on duration of the signal lamp of each road section according to the target values of the traffic flow of each road section, so as to realize mixed traffic flow control in the target road network.

[0109] In the scheme, optionally, the flow distribution constraint includes:

[0110]

[0111]

[0112]

[0113]

[0114] where w denotes a start-end point combination index, denotes a set of start-end point combinations, d w denotes the admitted traffic flow on path r in start-end point combination w, denotes the non-admitted traffic flow on path r in start-end point combination w, r denotes a path index in start-end point combination w, denotes a set of paths in start-end point combination w, denotes a set of feasible paths for all start-end point combinations, f r denotes the traffic flow on path r in start-end point combination w, ij denotes a link with link origin node i and link end node j, denotes a set of links, denotes the association between link ij and path r, π ij denotes the traffic flow on link ij.

[0115] In one possible implementation, the first road capacity constraint includes:

[0116]

[0117]

[0118] where β ∈ (0, 1) denotes a buffer parameter, denotes a set of entry nodes, denotes a set of exit nodes, denotes a set of intersections, denotes a set of links between node n1 and node n2 that are outside the intersection, ij denotes a link with link origin node i and link end node j, π ij denotes the traffic flow on link ij, denotes the number of lanes for the link between node n1 and node n2, h f denotes the average headway of the mixed traffic flow, T C denotes the signal control cycle of the signal light, g ij denotes the green time on link ij, denotes a set of intersection links, L ij denotes the number of lanes for intersection link ij. Optionally, the signal light constraint includes:

[0119]

[0120]

[0121] The signal light phase difference constraint includes:

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129] wherein, denotes a set of intersection road segments, n denotes an intersection road segment index, m denotes a phase index, phase 1 denotes a first pair of left-turn phases, phase 2 denotes a first pair of straight phases, phase 3 denotes a second pair of left-turn phases, and phase 4 denotes a second pair of straight phases, denotes a green time of intersection road segment n phase m, G min denotes a minimum green time, G max denotes a maximum green time, g ij denotes a green time on road segment ij, denotes a set of mixed traffic flow directions of intersection n phase m, T C denotes a signal control cycle of a signal light, denotes a phase difference of intersection road segment n phase m, θ i denotes a phase difference of node i, denotes a periodicity description parameter of signal control,

[0130] In a preferred scheme, the road segment travel time constraints include intersection road segment constraints, connecting road segment constraints, exit road segment constraints, and entry road segment constraints; the intersection road segment, connecting road segment, exit road segment, and entry road segment are determined based on a node type of a road segment start point and a road segment end point; the node type includes a split node, a merge node, an entry node, and an exit node;

[0131] the road segment end point of the intersection road segment is a split node, and the road segment start point is a merge node of the same intersection;

[0132] the road segment end point of the connecting road segment is a merge node, and the road segment start point is a split node of an adjacent intersection;

[0133] the road segment end point of the entry road segment is an entry node, and the road segment start point is a split node;

[0134] The road segment endpoint of the exit road segment is a merging node, and the road segment starting point is an exit node;

[0135] The intersection road segment constraint comprises:

[0136]

[0137]

[0138]

[0139] The connection road segment constraint comprises:

[0140]

[0141]

[0142]

[0143] The exit road segment constraint comprises:

[0144] The entry road segment constraint comprises:

[0145] Wherein, represents a set of intersection road segments, represents a set of connection road segments, represents a set of exit road segments, represents a set of entry road segments, ij represents the travel time on the road segment ij with the road segment starting point being node i and the road segment endpoint being node j, represents the travel time on the road segment ij at the maximum speed, i represents the phase difference of node i, determined according to the current phase of node i, j represents the phase difference of node j, determined according to the current phase of node j, C represents the signal control period of the signal light, ij represents the periodicity description parameter of the phase difference.

[0146] In this embodiment, the first relationship is Wherein, ij represents a road segment with the road segment starting point being node i and the road segment endpoint being node j, represents a set of road segments, ij represents the traffic flow of the road segment ij, ij represents the travel time on the road segment ij, and w represents a start-end point combination

[0147] index, represents a set of start-end point combinations, T represents the non-admitted traffic flow matched with the start-stop point combination w H represents an offline control period;

[0148] The first relationship formula value constraint is determined according to the sorting result of each calculation result of the first relationship formula; each calculation result of the first relationship formula satisfies the traffic distribution constraint, the first road capacity constraint, the signal light time constraint, the signal light phase difference constraint and the road section travel time constraint.

[0149] On the basis of the above scheme, optionally, the device further comprises an admission control module, configured to:

[0150] When the predetermined second relationship formula satisfies the second constraint condition, the green light on duration of each entry signal light of the target road network in the preset online control period is determined to realize the admission control of the mixed traffic flow;

[0151] The second relationship formula is determined according to the cumulative length of each entry vehicle of the target road network and the vehicle residence flow in the online control period; the second constraint condition includes the second road capacity constraint, the entry flow limit constraint and the second relationship formula value constraint;

[0152] The second road capacity constraint is determined based on the traffic flow prediction result of the upstream and downstream road sections of the target road network in the current online control period;

[0153] The traffic flow prediction result is determined according to the traffic flow of the upstream and downstream connected road sections of the target road network in the last online control period, the green light on duration of the associated road section signal light of the upstream and downstream connected road sections, the number of lanes of the upstream and downstream connected road sections, the average headway of the mixed traffic flow and the traffic capacity of the upstream and downstream connected road sections.

[0154] The mixed traffic flow control device provided by the embodiments of the present application can execute the mixed traffic flow control method provided by any embodiment of the present application, and has the corresponding function modules and beneficial effects of the execution method.

[0155] Embodiment four

[0156] Figure 4A schematic diagram of an electronic device 410 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0157] like Figure 4 As shown, the electronic device 410 includes at least one processor 411 and a memory, such as a read-only memory (ROM) 412 or a random access memory (RAM) 413, communicatively connected to the at least one processor 411. The memory stores computer programs executable by the at least one processor. The processor 411 can perform various appropriate actions and processes based on the computer program stored in the ROM 412 or loaded from storage unit 418 into the RAM 413. The RAM 413 may also store various programs and data required for the operation of the electronic device 410. The processor 411, ROM 412, and RAM 413 are interconnected via a bus 414. An input / output (I / O) interface 415 is also connected to the bus 414.

[0158] Multiple components in electronic device 410 are connected to I / O interface 415, including: input unit 416, such as keyboard, mouse, etc.; output unit 417, such as various types of displays, speakers, etc.; storage unit 418, such as disk, optical disk, etc.; and communication unit 419, such as network card, modem, wireless transceiver, etc. Communication unit 419 allows electronic device 410 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0159] Processor 411 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 411 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 411 performs the various methods and processes described above, such as methods for controlling mixed traffic flows.

[0160] In some embodiments, the control method of mixed traffic flow can be implemented as a computer program tangibly embodied in a computer readable storage medium, e.g., storage unit 418. In some embodiments, parts or all of the computer program can be loaded and / or installed onto electronic device 410 via, e.g., ROM 412 and / or communication unit 419. When the computer program is loaded onto RAM 413 and executed by processor 411, one or more steps of the above-described control method of mixed traffic flow can be performed. Alternatively, in other embodiments, processor 411 can be configured to perform the control method of mixed traffic flow by other means, e.g., with the aid of firmware.

[0161] Various implementations of the systems and techniques described above can be realized in digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0162] Computer programs used to implement the methods of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the computer program, when executed by the processor of the machine, implements the functions / acts specified in the flowcharts and / or block diagrams. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine and partially on a remote machine or entirely on a remote machine or server.

[0163] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0164] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0165] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0166] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0167] It should be understood that the various forms of flow shown above can be reordered, added to, or have steps deleted. For example, the steps described in the present application can be performed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, and this is not limited herein.

[0168] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A control method of a mixed traffic flow, characterized by, The method comprises: determining a first relationship in a preset off-line control period according to traffic flow of each road section in a target road network, passing time of each road section, and non-admission traffic flow matched with each start-end point combination; wherein the start-end point combination is determined based on the entrance and exit of the target road network; the road section comprises an intersection road section, a connecting road section, an entrance road section, and an exit road section; and the first relationship represents total passing cost of all vehicles in the target road network; when the first relationship satisfies a first constraint condition, determining target values of traffic flow of each road section; wherein the first constraint condition comprises a flow distribution constraint, a first road capacity constraint, a signal time constraint, a signal phase difference constraint, a road passing time constraint, and a first relationship value constraint; determining the green light duration of each road signal according to the target values of traffic flow of each road section, so as to realize mixed traffic flow control in the target road network; wherein the flow distribution constraint comprises: where w denotes the origin-destination combination index, denotes the set of origin-destination combinations, d w denotes the admitted traffic flow matching the origin-destination combination w, denotes the non-admitted traffic flow matching the origin-destination combination w, r denotes the path index in the origin-destination combination w, denotes the set of paths in the origin-destination combination w, denotes the set of feasible paths for all origin-destination combinations, f r denotes the traffic flow on path r in the origin-destination combination, ij denotes the link with the origin node i and the end node j, denotes the set of links, denotes the association between link ij and path r, π ij denotes the traffic flow on link ij; the first road capacity constraint comprises: where β ∈ (0, 1) represents a buffer parameter, represents an entrance node set, represents an exit node set, represents a set of intersections, represents a set of road segments between node n1 and node n2 outside the intersection, ij represents a road segment with the starting point of the road segment being node i and the ending point of the road segment being node j, π ij represents the traffic flow of the road segment ij, represents the number of lanes of the road segment between node n1 and node n2, h f represents the average headway of the mixed traffic flow, T C represents the signal control cycle of the signal light, g ij represents the green time of the road segment ij, represents a set of intersection road segments, L ij represents the number of lanes of the intersection road segment ij.

2. The method of claim 1, wherein, the signal time constraint comprises: the signal phase difference constraint comprises: wherein, denotes the set of intersections, n denotes the intersection index, m denotes the phase index, phase 1 denotes the first pair of left-turn phases, phase 2 denotes the first pair of straight phases, phase 3 denotes the second pair of left-turn phases, phase 4 denotes the second pair of straight phases, denotes the green time of intersection n phase m, G min denotes the minimum green time, G max denotes the maximum green time, g ij denotes the green time on link ij, denotes the set of mixed traffic flow directions of intersection n phase m, T C denotes the signal control cycle of a signal, denotes the phase difference of intersection n phase m, Θ i denotes the phase difference of node i, denotes the periodicity description parameter of signal control, 3. The method of claim 1, wherein, the road passing time constraint comprises intersection road section constraint, connecting road section constraint, exit road section constraint, and entrance road section constraint; the intersection road section, the connecting road section, the exit road section, and the entrance road section are determined based on the node type of the road section start point and the road section end point; and the node type comprises a separation node, a convergence node, an entrance node, and an exit node; the road section end point of the intersection road section is a separation node, and the road section start point is a convergence node of the same intersection; the road section end point of the connecting road section is a convergence node, and the road section start point is a separation node of an adjacent intersection; the road section end point of the entrance road section is an entrance node, and the road section start point is a separation node; the road section end point of the exit road section is a convergence node, and the road section start point is an exit node; the intersection road section constraint comprises: the connecting road section constraint comprises: The exit link constraints include: The entry link constraints include: wherein, denotes a set of intersection links, denotes a set of connecting links, denotes a set of exit links, denotes a set of entry links, t ij denotes the travel time on link ij with node i as the start of the link and node j as the end of the link, denotes the travel time on link ij at maximum speed, θ i denotes the phase difference of node i, determined according to the current phase of node i, θ j denotes the phase difference of node j, determined according to the current phase of node j, T C denotes the signal control period of the signal light, α ij denotes the periodicity description parameter of the phase difference.

4. The method of claim 1, wherein, The first relationship is where ij represents a road segment with the start node i and the end node j, represents a road segment set, π ij represents the traffic flow of the road segment ij, t ij represents the travel time on the road segment ij, w represents a start-end node combination index, represents a start-end node combination set, represents the non-admitted traffic flow matched by the start-end node combination w, T h represents an off-line control period; the first relationship value constraint is determined according to the sorting result of each calculation result of the first relationship; each calculation result of the first relationship satisfies the flow distribution constraint, the first road capacity constraint, the signal time constraint, the signal phase difference constraint, and the road passing time constraint.

5. The method according to any one of claims 1 to 4, characterized in that, after determining the green light duration of each road signal, the method further comprises: when a second relationship satisfies a second constraint condition, determining the green light duration of each entrance signal of the target road network in a preset on-line control period, so as to realize admission control of the mixed traffic flow; wherein the second relationship is determined according to the cumulative length of each entrance vehicle and the vehicle detention flow of the target road network in the on-line control period; and the second constraint condition comprises a second road capacity constraint, an entrance flow limitation constraint, and a second relationship value constraint; the second road capacity constraint is determined based on the traffic flow prediction result of the upstream and downstream road sections of the target road network in the current on-line control period; ​ The traffic flow prediction result is determined according to traffic flows of upstream and downstream connecting road sections of the target road network in a previous online control period, green light on durations of associated road section traffic lights of the upstream and downstream connecting road sections, numbers of lanes of the upstream and downstream connecting road sections, average headway of mixed traffic flows, and traffic capacities of the upstream and downstream connecting road sections.

6. A control device for mixed traffic flow, characterized by Comprise: A first relationship determination module is configured to determine a first relationship in a preset offline control period according to traffic flows of road sections in the target road network, travel times of the road sections, and non-admission traffic flows matched with each origin-destination combination, wherein the origin-destination combination is determined based on entries and exits of the target road network, the road sections comprise intersection road sections, connecting road sections, entry road sections, and exit road sections, and the first relationship represents a total travel cost of all vehicles in the target road network; A target value determination module is configured to determine target values of the traffic flows of the road sections when the first relationship satisfies a first constraint condition, wherein the first constraint condition comprises a flow distribution constraint, a first road capacity constraint, a traffic light time constraint, a traffic light phase difference constraint, a road section travel time constraint, and a first relationship value constraint; A traffic flow control module is configured to determine green light on durations of traffic lights of the road sections according to the target values of the traffic flows of the road sections, so as to implement mixed traffic flow control in the target road network. The flow distribution constraint comprises: where w denotes the origin-destination combination index, denotes the set of origin-destination combinations, d w denotes the admitted traffic flow matching the origin-destination combination w, denotes the non-admitted traffic flow matching the origin-destination combination w, r denotes the path index in the origin-destination combination w, denotes the set of paths in the origin-destination combination w, denotes the set of feasible paths for all origin-destination combinations, f r denotes the traffic flow on path r in the origin-destination combination, ij denotes the link with the origin node i and the end node j, denotes the set of links, denotes the association between link ij and path r, π ij denotes the traffic flow on link ij; The first road capacity constraint comprises: where β ∈ (0, 1) represents a buffer parameter, represents an entrance node set, represents an exit node set, represents a crossing set, represents a link set between node n1 and node n2 outside the crossing, ij represents a link with the link start node i and the link end node j, π ij represents the traffic flow of link ij, represents the number of lanes of the link between node n1 and node n2, h f represents the average headway of the mixed traffic flow, T C represents the signal control cycle of the signal light, g ij represents the green time of link ij, represents a crossing link set, l ij represents the number of lanes of the crossing link ij.

7. An electronic device, comprising: The electronic device comprises: At least one processor; and A memory connected with the at least one processor in communication; wherein The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the mixed traffic flow control method in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions, and the computer instructions are used to enable the processor to implement the mixed traffic flow control method in any one of claims 1-5 when executed.

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