A cloud-edge collaborative intersection overflow control method, system, device and medium

Abstract

The present invention relates to a cloud-edge collaborative intersection overflow control method, system, device and medium, wherein the method comprises: responding to the overflow alarm information at the intersection exit, determining the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections; according to the overflow response at the edge end, obtaining the dissipation speed of the overflow congestion / gathering based on the acquired inflow and outflow flow of the overflow section; determining the green light adjustment time based on the dissipation speed, the preset number of overflow vehicles and the green light time, and combining the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections to generate and adjust the signal control scheme of the downstream intersection and / or the overflow intersection; after the queue is dissipated, gradually adjusting the green light time until the departure rate of the overflow section is not less than the arrival rate, and restoring to the scheme before the dynamic adjustment. The present invention successfully solves many problems existing in the existing intersection coordination schemes through cloud-edge collaborative, intelligent signal timing control and dynamic adjustment strategies.

Description

Technical Field

[0001] The present invention relates to the field of intelligent transportation technology, and in particular to a cloud-edge collaborative intersection overflow control method, system, device and medium. Background Art

[0002] In modern urban traffic management, intersection overflow has become one of the important factors causing traffic congestion and safety accidents. When the number of vehicles at an intersection exceeds its designed carrying capacity, overflow will occur. If this situation is not handled promptly and effectively, it will not only significantly reduce the traffic efficiency of the intersection, but may also further cause a chain reaction on surrounding roads, ultimately leading to a wider range of traffic paralysis.

[0003] Traditional traffic signal control systems usually rely on fixed signal timing schemes to deal with intersection overflow challenges. However, this fixed scheme has significant deficiencies in flexibility and real-time performance. Since it cannot be adjusted in a timely manner according to dynamic factors such as actual traffic flow and road conditions, and does not exclude the influence of upstream and downstream waiting areas, it is often ineffective in dealing with overflow problems and may even lead to further deterioration of the overflow situation. This lack of adaptability in signal control has made it difficult to meet the complex and ever-changing traffic management needs of modern cities. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a cloud-edge collaborative intersection overflow control method, system, equipment and medium, which solves the technical problem that the existing intersection coordination scheme cannot be adjusted in time according to dynamic factors such as actual traffic flow and road conditions and does not eliminate the influence of upstream and downstream waiting areas, resulting in road section capacity overflow.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, an embodiment of the present invention provides a cloud-edge collaborative intersection overflow control method, comprising:

[0009] In response to the intersection exit overflow alarm information, determine the overflow exit direction and the phase of the associated flow direction of the upstream and downstream intersections;

[0010] According to the overflow response at the edge, the dissipation speed of overflow congestion / aggregation is calculated based on the inflow and outflow flow of the overflow section obtained;

[0011] Determine the green light adjustment time based on the obtained dissipation speed of overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generate and dynamically adjust the signal control plan of the downstream intersection and / or overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections;

[0012] After the queue on the overflow section dissipates, the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection is gradually adjusted until the departure rate of the overflow section is not less than the arrival rate, and the original signal control scheme before the dynamic adjustment is restored.

[0013] Optionally, according to the overflow response of the edge end, obtaining the dissipation speed of the overflow congestion / aggregation based on the acquired inflow and outflow traffic of the overflow section includes:

[0014] After the edge end implements overflow response according to the overflow alarm information at the intersection exit, the real-time inflow and outflow flow data of the overflow section are obtained through the detection equipment deployed at the edge end;

[0015] The acquired real-time inflow traffic data and outflow traffic data are processed to calculate the total inflow traffic and total outflow traffic of the overflow section respectively. The inflow traffic is the sum of the left-turn, straight-ahead, and right-turn inflow traffic of the associated phase flowing into the overflow section, and the outflow traffic is the sum of the left-turn, straight-ahead, and right-turn outflow traffic of the associated phase flowing out of the overflow section.

[0016] Calculate the congestion build-up / dissipation speed based on the total inflow and outflow data;

[0017] When overflow is detected at the intersection exit, the overflow response at the edge end includes:

[0018] The following operations are performed on the downstream intersection: if the associated phase of the downstream intersection is a red light, the associated phase green light is started early; if the associated phase of the downstream intersection is a green light, a green light is added to extend the time;

[0019] The following operations are performed on the overflow intersection: if the associated phase of the overflow intersection is a red light, the red light time is extended; if the associated phase of the overflow intersection is a green light, the green light is disconnected early; if the next phase is still an associated phase, the phase is jumped to a non-associated phase.

[0020] Optionally, determining the green light adjustment time based on the obtained dissipation speed of the overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generating a signal control scheme for the downstream intersection and / or the overflow intersection in combination with the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections includes:

[0021] Determine the time required for dissipation based on the dissipation speed of the overflow congestion / agglomeration and the preset number of overflow vehicles;

[0022] Add a green light at the downstream intersection to extend the time and form a dissipating wave;

[0023] Allocate the green light extension time to the left-turn and through-travel outflow phases of the downstream intersection according to a set ratio, and calculate the flow rate and the departure rate of the overflow section of the left-turn and through-travel outflow phases of the downstream intersection after allocating the green light extension time, so as to determine the adjusted dissipation speed of overflow congestion / aggregation;

[0024] With the goal of clearing the queue, the green light time for straight and left turns in the associated phase of the downstream intersection is solved, and the green light extension time of the non-associated phase of the downstream intersection is reduced while keeping the cycle unchanged;

[0025] If the green light time for straight and left turns in the associated phase of the downstream intersection is the maximum green light time, the maximum green light time for the associated phase of the downstream intersection is configured, and the inflow phase of the overflow intersection is reduced by one green light to shorten the time;

[0026] Allocate the shortened green light time to the left-turn and through-travel inflow phases of the overflow intersection according to a set ratio, and calculate the flow rate of the left-turn and through-travel inflow phases of the overflow intersection after allocating the shortened green light time and the arrival rate of the overflow section to determine the adjusted dissipation speed of the overflow congestion / aggregation;

[0027] With the goal of clearing the queue, the green light time for straight and left turns in the associated phases of the overflow intersection is solved, and the green light time for non-associated phases of the overflow intersection is shortened while keeping the cycle unchanged;

[0028] If the green light times for straight and left turns in the associated phases of the overflow intersection both take the minimum green light time, then configure the maximum green light time for the associated phases of the downstream intersection and the minimum green light time for the associated phases of the overflow intersection, and request manual intervention.

[0029] Optionally, the signal control scheme for dynamically adjusting the downstream intersection and / or the overflow intersection includes:

[0030] The larger one of the cycles at the overflow intersection and the downstream intersection is selected as the common cycle, and the downstream intersection is determined as the key intersection;

[0031] The phase with the largest associated flow direction is selected as the coordination phase;

[0032] Calculate the difference between the end time of the signal control scheme of the overflow intersection and the downstream intersection, and use the obtained difference as the first phase difference of the signal control scheme of the current downstream intersection and / or the overflow intersection;

[0033] Calculate the coordinated phase difference, and adjust the coordinated phase difference according to the requirements of coordinated control, and then obtain the phase difference change;

[0034] Configure the overflow intersection and downstream intersection to use the green-to-signal ratio of their original solutions;

[0035] If the phase difference variation is positive or negative, adjusting the signal control scheme of the downstream intersection and / or the overflow intersection based on the cycle of the overflow intersection, the cycle of the downstream intersection and the phase difference variation;

[0036] Based on the adjusted signal control scheme of the downstream intersection and / or the overflow intersection, the green light time of the coordinated phase-associated flow direction of the overflow intersection is verified to determine whether the green light time of the coordinated phase-associated flow direction of the overflow intersection is less than or equal to the corresponding green light time of the downstream intersection;

[0037] If the green light time of the flow direction associated with the coordinated phase of the overflow intersection is not less than or equal to the corresponding green light time of the downstream intersection, the flow direction that exceeds the time is subject to early disconnection processing;

[0038] in,

[0039] The phase difference change is:

[0040] Δt p =min[t p -t' p |,|T-(t p -t' p )|]

[0041] Where, t p is the coordinated phase difference, t' p is the coordinated phase difference after adjustment, T is the common period;

[0042] When the phase difference change is greater than 0, adjust the cycle T tran :

[0043] T tran =min[T1,T2]+Δt p ;

[0044] When the phase difference change is less than 0, adjust the cycle T tran :

[0045] T tran =max[T1,T2]+Δt p .

[0046] Optionally, after determining the green light adjustment time based on the obtained dissipation speed of the overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generating and dynamically adjusting the signal control scheme of the downstream intersection and / or the overflow intersection in combination with the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections, it also includes:

[0047] When the green light time of the downstream associated phase increases, monitor whether the dissipation period will cause vehicle overflow at the exit of the downstream section;

[0048] If the departure rate of the downstream section exit is greater than or equal to the arrival rate, the current signal control scheme will continue to be maintained;

[0049] If the exit rate of the downstream section exit is less than the arrival rate, determine whether the set overflow judgment condition is met;

[0050] If the overflow judgment condition is not met, the green light time of the corresponding outflow phase of at least two adjacent sections of the downstream section is increased by accumulating second by second to increase the exit rate of the overflow at the downstream section outlet until the overflow judgment condition is met;

[0051] After the overflow judgment conditions are met, recalculate and verify whether the capacity of all affected sections is met;

[0052] The overflow judgment condition is:

[0053] (g+Δg)·(Q i+1,in -Q i+1,out )≤l i+1 ;

[0054] In the formula, g is the green light time, Δg is the green light adjustment time, Q i+1,in is the exit rate of the downstream section’s exit overflow, Q i+1,out is the overflow rate at the downstream exit, l i+1 The number of vehicles queuing on the downstream road segment.

[0055] Optionally, after the queue of the overflow section is dissipated, the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection is gradually adjusted until the departure rate of the overflow section is not less than the arrival rate, and the original signal control scheme before the dynamic adjustment is restored includes:

[0056] After the queue on the overflow section begins to dissipate, gradually reduce the green light time of the associated phase of the downstream intersection, record the changes in the departure rate and arrival rate of the overflow section after each adjustment, until the departure rate of the overflow section is not less than the arrival rate, and gradually restore the green light time to the original signal control scheme before dynamic adjustment;

[0057] If the condition that the departure rate is not less than the arrival rate cannot be met by adjusting the associated phase of the downstream intersection alone, the green light time of the associated phase of the overflow intersection is gradually increased simultaneously or separately, and the changes in the departure rate and arrival rate of the overflow section after each adjustment are recorded;

[0058] By continuously adjusting the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection until the departure rate of the overflow section is no less than the arrival rate, the green light time is gradually restored to the original signal control scheme before the dynamic adjustment.

[0059] Optionally, if there is no intersection downstream of the overflow intersection or the downstream intersection is uncontrollable,

[0060] Receive and transmit the alarm information of the overflow section to the central server to obtain the upstream and downstream road network relationship of the overflow section, and determine the overflow exit direction and the associated flow phase of the upstream and downstream intersections;

[0061] According to the red or green light status of the associated phase of the overflow intersection, the red light time of the overflow intersection is extended accordingly or the green light is turned off early;

[0062] Configure the number of overflow vehicles that need to be dissipated immediately, and use the saturated headway to calculate the time required to leave;

[0063] According to the time required to leave, adjust the green light time of the downstream intersection and the green light time of the upstream intersection;

[0064] If there is no alarm information of overflow section in the next cycle, the schemes of upstream and downstream intersections will be gradually restored to the original signal control scheme until the traffic volume returns to the pre-congestion level;

[0065] If there is still alarm information about overflow sections in the next cycle, configure the maximum green light time for the downstream associated phase operation and the minimum green light time for the upstream associated phase operation, and request manual disposal.

[0066] In a second aspect, an embodiment of the present invention provides a cloud-edge collaborative intersection overflow control system, including:

[0067] A signal determination module, for responding to the overflow alarm information at the intersection exit, determining the overflow exit direction and the phase of the associated flow direction of the upstream and downstream intersections;

[0068] A dissipation speed output module is used to obtain the dissipation speed of overflow congestion / aggregation based on the overflow response of the edge end and the inflow and outflow flow of the overflow section;

[0069] A scheme generation and adjustment module is used to determine the green light adjustment time based on the obtained dissipation speed of overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generate and dynamically adjust the signal control scheme of the downstream intersection and / or the overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections;

[0070] The scheme callback module is used to gradually adjust the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection after the queue of the overflow section dissipates, until the departure rate of the overflow section is not less than the arrival rate, and restore to the original signal control scheme before dynamic adjustment.

[0071] In a third aspect, an embodiment of the present invention provides a cloud-edge collaborative intersection overflow control device, including:

[0072] At least one detection device, deployed at the edge, configured to obtain various types of traffic information and generate intersection exit overflow alarm information;

[0073] The edge processing center is configured to implement overflow response according to the intersection exit overflow alarm information transmitted by the detection device;

[0074] The central server is configured to execute the cloud-edge collaborative intersection overflow control method as described above, and to communicate with the edge processing center to achieve data interaction and instruction delivery;

[0075] And, at least one database configured to store and process data generated by the interaction with the central server and the edge processing center.

[0076] In a fourth aspect, an embodiment of the present invention provides a computer-readable medium having computer executable instructions stored thereon, which, when executed by a processor, implements the method for cloud-edge collaborative intersection overflow control as described above.

[0077] (III) Beneficial effects

[0078] The beneficial effects of the present invention are:

[0079] First, the present invention receives overflow alarm information at intersection exits in real time through cloud-edge collaboration, and quickly determines the overflow direction and related flow phase, thus achieving accurate grasp of traffic conditions. This function greatly improves the timeliness and pertinence of traffic management.

[0080] Furthermore, the present invention uses the overflow response mechanism at the edge to intelligently obtain the road network relationship between the upstream and downstream of the overflow section and calculate the dissipation speed of the overflow queue. This not only provides a scientific basis for the subsequent green light time adjustment, but also ensures the effectiveness and rationality of traffic diversion measures.

[0081] More importantly, the present invention can dynamically adjust the green light time according to the dissipation speed, and dissipate the vehicles stuck in the intersection through refined signal timing control. This dynamic adjustment strategy not only effectively prevents the exit from overflowing again, but also significantly improves the traffic efficiency of the road section, thereby alleviating urban traffic congestion.

[0082] In addition, the invention also coordinates the flow direction of entering and leaving the overflow section, ensuring the balance of vehicle arrival rate and departure rate. This innovative measure not only optimizes traffic flow, but also reduces traffic safety risks caused by overflow of road section capacity.

[0083] Therefore, the present invention improves the effect of intersection overflow control in all aspects through cloud-edge collaboration, intelligent signal timing control and dynamic adjustment strategy, and successfully solves many problems existing in existing intersection coordination schemes, such as the inability to make timely adjustments based on dynamic factors such as actual traffic flow and road conditions, and the failure to exclude the influence of upstream and downstream waiting areas. Its beneficial effect is not only reflected in improving the efficiency and accuracy of urban traffic management, but also in providing a safer and smoother travel environment for urban residents. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 A flowchart of a cloud-edge collaborative intersection overflow control method provided by an embodiment of the present invention;

[0085] Figure 2 A schematic diagram of intersection overflow of a cloud-edge collaborative intersection overflow control method provided in an embodiment of the present invention;

[0086] Figure 3 A specific flow chart of step S1 of a cloud-edge collaborative intersection overflow control method provided by an embodiment of the present invention;

[0087] Figure 4 A specific flow chart of a part of step S3 of a cloud-edge collaborative intersection overflow control method provided by an embodiment of the present invention;

[0088] Figure 5 A green light adjustment time calculation process of a cloud-edge collaborative intersection overflow control method provided in an embodiment of the present invention;

[0089] Figure 6 A specific flow chart of another part of step S3 of a cloud-edge collaborative intersection overflow control method provided by an embodiment of the present invention;

[0090] Figure 7 A specific flow chart of step S4 of a cloud-edge collaborative intersection overflow control method provided by an embodiment of the present invention;

[0091] Figure 8 An overall flow chart of a cloud-edge collaborative intersection overflow control method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0092] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0093] like Figure 1 As shown, a cloud-edge collaborative intersection overflow control method proposed in an embodiment of the present invention includes: responding to overflow alarm information at an intersection exit, determining the overflow exit direction and the associated flow phase of upstream and downstream intersections; according to the overflow response of the edge end, obtaining the dissipation speed of the overflow congestion / gathering based on the acquired inflow and outflow flow of the overflow section; determining the green light adjustment time based on the obtained dissipation speed of the overflow congestion / gathering, the preset number of overflow vehicles and the green light time, and generating and dynamically adjusting the signal control scheme of the downstream intersection and / or the overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections; after the queue of the overflow section is dissipated, gradually adjusting the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection until the departure rate of the overflow section is not less than the arrival rate, and restoring to the original signal control scheme before the dynamic adjustment.

[0094] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0095] Specifically, an embodiment of the present invention provides a cloud-edge collaborative intersection overflow control method, including:

[0096] S1. In response to overflow alarm information at an intersection exit, determine the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections.

[0097] Edge detection equipment includes traffic flow monitors, cameras, vehicle identification systems, etc., which are distributed at various key nodes of the road traffic network to collect traffic data in real time. When the edge detection equipment detects vehicle overflow on a certain road section, it will immediately generate an alarm message and send the information to the central server and the edge processing center. After receiving the alarm message, the central server will quickly parse and process it to determine the overflow exit direction and the associated flow phase of the upstream and downstream intersections. This includes information such as the topological structure of the traffic network where the overflow section is located, the traffic conditions of the adjacent sections, and possible traffic flow directions.

[0098] Obviously, according to Figure 2 , the red arrow flow direction represents the upstream associated flow direction phase, that is, the vehicles are driving from these directions to the overflow section; and the green arrow flow direction represents the downstream associated flow direction phase, that is, the vehicles are driving from the overflow section to these directions.

[0099] S2. According to the overflow response at the edge, the dissipation speed of the overflow congestion / aggregation is calculated based on the obtained inflow and outflow traffic of the overflow section.

[0100] Furthermore, if Figure 3 As shown, step S2 includes:

[0101] S11. After the edge end implements an overflow response according to the overflow alarm information at the intersection exit, the real-time inflow flow data and outflow flow data of the overflow section are obtained through the detection equipment deployed at the edge end.

[0102] Specifically, when overflow is detected at the intersection exit, the overflow response at the edge end includes: performing the following operations on the downstream intersection: if the associated phase of the downstream intersection is a red light, the green light of the associated phase is turned on early; if the associated phase of the downstream intersection is a green light, a green light is added to extend the time. Performing the following operations on the overflow intersection: if the associated phase of the overflow intersection is a red light, the red light time is extended; if the associated phase of the overflow intersection is a green light, the green light is turned off early; if the next phase is still an associated phase, the phase is jumped to a non-associated phase. In this way, traffic flow can be controlled more effectively to avoid multiple consecutive phases being affected by overflow.

[0103] Through the implementation of the above strategies, the edge processing center can quickly respond to the overflow situation at the intersection exit based on real-time traffic data. This is a relatively extensive emergency response, laying the foundation for further detailed overflow control by the central server in subsequent cycles.

[0104] S12. Process the acquired real-time inflow traffic data and outflow traffic data, and calculate the total inflow traffic and total outflow traffic of the overflow section respectively. The inflow traffic is the sum of the left-turn, straight-ahead, and right-turn inflow traffic of the associated phases flowing into the overflow section, and the outflow traffic is the sum of the left-turn, straight-ahead, and right-turn outflow traffic of the associated phases flowing out of the overflow section.

[0105] S13. Calculate the congestion gathering / dissipation speed based on the total inflow flow and the total outflow flow data. In a specific embodiment, the overflow queue dissipation speed is calculated as follows:

[0106] v w =Q i,out -Q i,in

[0107] Q i,out =q l,out +q s,out +q r,out

[0108] Q i,in =q l,in +q s,in +q r,in

[0109] In the formula, Q i,out is the outflow flow of the overflow section, q l,out ,q s,out ,q r,out They are the outflow phase flow rates of left turn, straight going and right turn in the associated phase respectively. i,in is the inflow flow of the overflow section, q l,in ,q s,in ,q r,in is the associated phase left, straight, and right flow into the overflow section (Note: for the flow into the overflow section from different directions, see Figure 2 , without considering U-turn input). w It is the speed of congestion gathering / dissipation (a positive value means congestion is dissipating, and a negative value means congestion is gathering).

[0110] S3. Determine the green light adjustment time based on the obtained dissipation speed of the overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generate and dynamically adjust the signal control plan for the downstream intersection and / or overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections.

[0111] Furthermore, if Figure 4 As shown, step S3 includes:

[0112] S31. Determine the time required for dissipation of the overflow congestion / aggregation according to the dissipation speed of the overflow congestion / aggregation and the preset number of overflow vehicles.

[0113] S32. Add a green light at the downstream intersection to extend the time and form a dissipating wave.

[0114] S33, allocating the green light extension time to the left-turn and straight-ahead outflow phases of the downstream intersection according to a set ratio, and calculating the flow rate and the departure rate of the overflow section of the left-turn and straight-ahead outflow phases of the downstream intersection after the green light extension time is allocated, so as to determine the adjusted dissipation speed of the overflow congestion / aggregation.

[0115] S34. With the goal of clearing the stranded queue, the green light time for straight and left turns in the associated phase of the downstream intersection is solved, and, under the premise of keeping the cycle unchanged, the green light extension time of the non-associated phase of the downstream intersection is reduced.

[0116] S35. If the green light times for going straight and turning left at the associated phase of the downstream intersection are both the maximum green light time, configure the maximum green light time for the associated phase of the downstream intersection, and reduce the green light time for the inflow phase of the overflow intersection.

[0117] S36. Allocate the shortened green light time to the left-turn and straight-ahead inflow phases of the overflow intersection according to a set ratio, and calculate the flow rate of the left-turn and straight-ahead inflow phases of the overflow intersection after allocating the shortened green light time and the arrival rate of the overflow section to determine the adjusted dissipation speed of the overflow congestion / aggregation.

[0118] S37, with the goal of clearing the stranded queue, solve the green light time for straight and left turns in the associated phase of the overflow intersection, and, under the premise of keeping the cycle unchanged, increase the green light shortening time of the non-associated phase of the overflow intersection.

[0119] S38. If the green light times for straight and left turns in the associated phase of the overflow intersection are both the minimum green light times, configure the maximum green light time for the associated phase of the downstream intersection and the minimum green light time for the associated phase of the overflow intersection, and request manual intervention.

[0120] In a specific embodiment, reference Figure 5 In the traffic congestion control strategy, a key goal is to ensure that the overflow queue vehicles in the intersection can be dispersed in the next cycle. This is mainly achieved by adjusting the green light time to ensure that the queue dissipation speed multiplied by the green light time of the next cycle is greater than or equal to the current overflow queue length.

[0121] First, we need to determine the time t required for dissipation:

[0122]

[0123] Among them, l n To preset the number of overflow vehicles (a parameter configured according to the intersection conditions).

[0124] In the process of generating the signal control plan for the downstream intersection, a green light extension time Δg is added to the downstream intersection. out , forming an evanescent wave.

[0125] Specifically, the green light is extended by Δg out Assigned to left turn and through phases:

[0126] Δg l,out +Δg s,out =Δg out ,

[0127] Where, Δg out is the total green time increase, Δg l,out , Δg s,out The green light time increased for left turn and straight going.

[0128] Furthermore, the green light time for left turns and straight driving downstream is increased:

[0129] g′ l,out =g l,out +Δg l,out , g' s,out =g s,out +Δg s,out

[0130] Among them, g l,out , g s,out is the green light time for the left turn and straight outflow phase, g′ l,out , g' s,out It is the adjusted green light time for left turn and straight outgoing phase.

[0131] Then, calculate the flow rate after adding the green light time:

[0132]

[0133] Among them, q l,out ,q s,out is the phase flow of left turn and straight flow. l,out , q' s,out It is the outflow phase flow rate for left turn and straight going after adjustment.

[0134] After adjustment, the departure rate of the overflow section is:

[0135] Q' out =q' s,out +q′ l,out +q r,out

[0136] The dissipation speed at this time is:

[0137] v w =Q' out -Q i,in

[0138] The goal of the signal control scheme at the downstream intersection is to ensure that the congestion in the intersection can be dissipated when the next left turn cycle and the green light time end. To this end, let t = g' l +g' s In order to optimize the traffic efficiency of the intersection and relieve congestion, a key parameter t is introduced, which represents the ratio of the number of stranded vehicles to the dissipation speed, that is, the time required for the stranded vehicles to dissipate. The goal of this invention is to adjust the traffic signal so that t can exactly match the green light time for left turn and straight. In this way, when the green light ends, all vehicles parked at the intersection can be released, thereby maximizing the traffic capacity of the intersection. In this way, by t = g' l +g' s Solving for g′ l,out and g' s,out The value of , that is, the green light time for straight and left turn operation in the associated phase, while the non-associated phase is reduced by Δg out (Allocate according to the original time ratio) to keep the cycle unchanged.

[0139] If g′ l,out and g′ l,inTake the maximum green light time, then the downstream intersection associated phase runs the maximum green light time, and the overflow intersection inflow phase reduces one green light to shorten the time Δg in At this time, the same method is used to form the signal control scheme for the overflow intersection:

[0140] Then, shorten the green light by Δg in Assigned to left turn and through phases:

[0141] Δg l,in +Δg s,in =Δg in ,

[0142] Where, Δg in is the total green time reduction, Δg l,out , Δg s,out The green light time for left turn and straight going phases is reduced respectively.

[0143] For overflow intersections, reduce the green light time for left turns and straight driving:

[0144] g′ l,in =g l,in -Δg l,in , g' s,in =g s,in -Δg s,in

[0145] Among them, g l,in , g s,in is the green light time associated with the left turn and straight going phases, g′ l,in , g' s,in It is the adjusted green light time for the associated left turn and straight going phases.

[0146] Calculate the flow rate after the green light of the associated phase is reduced:

[0147]

[0148] Among them, q l,in ,q s,out is the phase flow of left turn and straight flow. l,in , q' s,in It is the outflow phase flow rate for left turn and straight going after adjustment.

[0149] After adjustment, the arrival rate of the overflow section is:

[0150] Q′ in =q' s,in +q′ l,in +q r,in

[0151] The dissipation speed at this time is:

[0152] v w =Q′ out -Q′ in

[0153] Finally, the dissipation time is obtained:

[0154]

[0155] Let t = g l,max +g l,min (That is, when the next cycle of left turn and green light time of downstream ends, the congestion in the intersection will dissipate), and the solution is g′ l,in and g' s,in The value of the non-associated phase increases by Δg in (allocated according to the original time ratio) to keep the cycle unchanged. If g′ l,in and g' s,in If the minimum green light time is obtained, the minimum green light will be run and manual intervention will be requested.

[0156] In summary, the adjustment logic of the above two schemes follows the principle of increasing the green light time of the corresponding phase at the downstream intersection to increase the vehicle departure rate (in the oversaturated state, increasing the green light ratio corresponds to an increase in the flow of traffic flow), and reducing the green light time of the corresponding phase at the upstream intersection to reduce the vehicle arrival rate, thereby changing the road section from congestion gathering to congestion dissipation. By reasonably adjusting the green light time of the traffic lights, the departure rate and arrival rate of vehicles can be effectively controlled, thereby dissipating traffic congestion and restoring the normal traffic capacity of the road.

[0157] Furthermore, dynamically adjusting the signal control scheme of the downstream intersection and / or the overflow intersection includes: selecting the phase of the associated flow direction with the largest flow as the coordination phase; calculating the difference in the end time of the signal control scheme of the overflow intersection and the downstream intersection, and using the obtained difference as the first phase difference of the signal control scheme of the current downstream intersection and / or the overflow intersection; calculating the coordination phase difference, and adjusting the coordination phase difference according to the demand of coordinated control, and then obtaining the phase difference change; configuring the overflow intersection and the downstream intersection to adopt the green signal ratio of their respective original schemes; if the phase difference change is positive or negative, The signal control scheme of the downstream intersection and / or the overflow intersection is adjusted based on the cycle of the overflow intersection, the cycle of the downstream intersection and the phase difference change; the green light time of the coordinated phase-associated flow direction at the overflow intersection is verified based on the adjusted signal control scheme of the downstream intersection and / or the overflow intersection to determine whether the green light time of the coordinated phase-associated flow direction at the overflow intersection is less than or equal to the corresponding green light time at the downstream intersection; if the green light time of the coordinated phase-associated flow direction at the overflow intersection is not less than or equal to the corresponding green light time at the downstream intersection, early disconnection processing is implemented for the flow direction that exceeds the time.

[0158] In a specific embodiment, it is then necessary to adjust the phase difference coordinated control for the generated signal control scheme for the downstream intersection and / or the overflow intersection. The following are the key parameters and adjustment steps of the coordinated control:

[0159] (1) Cycle: Select the larger cycle of the two intersections as the common cycle, T = max[T1, T2].

[0160] (2) Critical intersection: Set the downstream intersection as the critical intersection and use it as a benchmark for coordinated control.

[0161] (3) Coordination phase: According to the configuration file, when accessing traffic data, the phase where the associated flow direction with the largest flow is located is selected as the coordination phase.

[0162] (4) Phase difference: Calculate the difference in the end time of the response plans of the two intersections as the first phase difference t of the current plan p0 , according to the coordinated phase difference = first phase difference + all phase times before the coordinated phase, calculate the coordinated phase difference t p , adjust the phase difference t' p =-3 (configurable). The phase difference change is

[0163]

[0164] (5) Green-to-signal ratio: the green-to-signal ratio of the original plan for each intersection.

[0165] Based on the above parameters and steps, the following adjustment plan is formulated:

[0166] ①Δt p >0, adjust the cycle T tran :

[0167] T tran =min[T1,T2]+Δt p ;

[0168] ②Δt p When <0, adjust the cycle T tran,i :

[0169] T tran =max[T1,T2]+Δt p ;

[0170] After calculating the adjustment plan, the green light time needs to be checked: the green light time of the overflow intersection coordination phase associated flow direction is less than or equal to the downstream intersection, g in ≤g out If the conditions are not met, the out-of-time flow will be issued for early disconnection to ensure the overall efficiency and safety of the traffic signal system.

[0171] Next, if Figure 6As shown, after determining the green light adjustment time based on the obtained dissipation speed of the overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and dynamically adjusting the signal control scheme of the downstream intersection and / or the overflow intersection in combination with the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections, it also includes:

[0172] A31. When the green light time of the downstream associated phase increases, monitor whether the dissipation period will cause vehicle overflow at the downstream road section exit.

[0173] A32. If the departure rate of the downstream section exit is greater than or equal to the arrival rate, continue to maintain the current signal control plan.

[0174] A33. If the departure rate of the downstream section exit is less than the arrival rate, determine whether the set overflow judgment condition is met.

[0175] A34. If the overflow judgment condition is not met, the green light time of the corresponding outflow phase of at least two adjacent sections of the downstream section is increased by accumulating second by second to increase the exit rate of the overflow at the downstream section outlet until the overflow judgment condition is met.

[0176] A35. After the overflow judgment conditions are met, recalculate and verify whether the capacity of all affected sections is met.

[0177] In a specific embodiment, when the downstream associated phase time increases, the corresponding downstream exit traffic volume increases. At this time, an important judgment needs to be made, that is, whether this increase will cause overflow at the downstream section exit during the dissipation period (the same logic applies to the upstream).

[0178] First, define the capacity of the downstream intersection, taking the through lane as an example:

[0179]

[0180] Among them, l i+1,s is the number of vehicles queuing on the downstream section, L i+1 is the length of the downstream section, l v is the saturated headway, and n is the number of lanes.

[0181] If Q i+1,out ≥Q i+1,in , then continue without making any adjustments.

[0182] If Q i+1,out <Q i+1,in Let the overflow judgment condition be: (g+Δg)·(Q i+1,in -Q i+1,out )≤l i+1 If not, the green light time of the outflow phase corresponding to the downstream i+2 segment is increased by seconds so that Q i+1,outIncrease until the inequality is satisfied. Among them, g is the green light time, Δg is the green light adjustment time, Q i+1,in is the exit rate of the downstream section’s exit overflow, Q i+1,out is the overflow rate at the downstream exit, l i+1 The number of vehicles queuing on the downstream section.

[0183] Through the above-mentioned logical adjustment and calculation, it is ensured that the adjusted green light time can meet the capacity requirements of all affected road sections.

[0184] S4. After the queue on the overflow section dissipates, gradually adjust the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection until the departure rate of the overflow section is not less than the arrival rate, and restore to the original signal control scheme before the dynamic adjustment.

[0185] Furthermore, if Figure 7 As shown, step S4 includes:

[0186] S41. After the queue on the overflow section begins to dissipate, gradually reduce the green light time of the associated phase at the downstream intersection, record the changes in the departure rate and arrival rate of the overflow section after each adjustment, until the departure rate of the overflow section is not less than the arrival rate, and gradually restore the green light time to the original signal control scheme before the dynamic adjustment.

[0187] S42. If the condition that the departure rate is not less than the arrival rate cannot be met by adjusting the associated phase of the downstream intersection alone, the green light time of the associated phase of the overflow intersection is gradually increased simultaneously or separately, and the changes in the departure rate and arrival rate of the overflow section after each adjustment are recorded.

[0188] S43, by continuously adjusting the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection until the departure rate of the overflow section is not less than the arrival rate, the green light time is gradually restored to the original signal control scheme before the dynamic adjustment.

[0189] After the queue in the intersection is dissipated, the green light time is adjusted (the phase associated with the downstream intersection decreases second by second, and the phase associated with the overflow intersection accumulates second by second) to ensure that the departure rate of the corresponding section is just greater than or equal to the arrival rate (just means that the current Q is satisfied). i,out ≥Q i,in , then increase the downstream phase green light time / decrease the overflow intersection phase green light time, then Q i,out <Q i,in ) until it is reduced (increased) to the original plan, and the adjustment is ended.

[0190] In addition, if there is no intersection downstream of the overflow intersection or the downstream intersection is uncontrollable, the alarm information of the overflow section is received and transmitted to the central server to obtain the upstream and downstream road network relationship of the overflow section, and determine the overflow exit direction and the phase of the associated flow direction of the upstream and downstream intersections; according to the red light or green light status of the associated phase of the overflow intersection, the red light time of the overflow intersection is correspondingly extended or the green light is executed early; the number of overflow vehicles that need to be dissipated immediately is configured, and the saturated headway is used to calculate the time required for departure; according to the time required for departure, the green light time of the associated flow direction of the downstream intersection and the green light time of the associated flow direction of the upstream intersection are adjusted; if there is no alarm information of the overflow section in the next cycle, the scheme of the upstream and downstream intersections will be gradually restored to the original signal control scheme until the traffic returns to the pre-congestion level; if there is still alarm information of the overflow section in the next cycle, the downstream associated phase is configured to run the maximum green light time, the upstream associated phase is configured to run the minimum green light time, and manual disposal is requested.

[0191] In another specific embodiment, first, an intersection exit overflow alarm is received, and the overflow exit direction and the overflow intersection-related flow direction are determined.

[0192] Next, determine the signal operation plan, and when overflow is detected:

[0193] (1) If the phase associated with the overflow intersection is a red light, the red light time will be extended.

[0194] (2) If the associated phase of the overflow intersection is green, the green light is disconnected early. If the next phase is still an associated phase, the phase is jumped to a non-associated phase.

[0195] Furthermore, calculate the green light adjustment time: configure the number of overflow vehicles that need to be dissipated immediately l n . Using the saturated headway time t n Calculate l n Time required to leave is t.

[0196] t=l n ·t n

[0197] Default n The queue length that overflows in one cycle will overflow again in the next cycle. n .

[0198] Considering that the overflowing queue vehicles in one cycle may still cause overflow in the next cycle, it is necessary to adjust the green light time of the upstream and downstream signal lights. Specifically, the green light time of the downstream signal associated flow direction is increased by t, while the green light time of the upstream associated flow direction is reduced by t. This adjustment is specific to each flow direction and is determined according to the green light time ratio of the original plan. If the adjusted green light time exceeds the maximum or minimum limit, the corresponding maximum or minimum green light time is run.

[0199] After the next cycle dissipates, the upstream intersection signal switches back to the original plan, and the downstream intersection remains unchanged. The algorithm ends when it is detected that the inflow direction of the upstream intersection has returned to the pre-congestion level and the downstream is switched back to the original plan.

[0200] If there is still an export overflow alarm in the next cycle, the downstream associated phase will run the maximum green light time, the upstream associated phase will run the minimum green light time, and manual disposal will be requested.

[0201] In addition, an embodiment of the present invention provides a cloud-edge collaborative intersection overflow control system, including:

[0202] The signal judgment module is used to respond to the overflow alarm information at the intersection exit and determine the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections.

[0203] The dissipation speed output module is used to calculate the dissipation speed of overflow congestion / aggregation based on the overflow response of the edge end and the acquired inflow and outflow flow of the overflow section.

[0204] The scheme generation and adjustment module is used to determine the green light adjustment time based on the obtained dissipation speed of overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and to generate and dynamically adjust the signal control scheme of the downstream intersection and / or overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections.

[0205] The scheme callback module is used to gradually adjust the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection after the queue of the overflow section dissipates, until the departure rate of the overflow section is not less than the arrival rate, and restore to the original signal control scheme before dynamic adjustment.

[0206] In addition, an embodiment of the present invention provides a cloud-edge collaborative intersection overflow control device, including: at least one detection device, deployed at the edge, configured to obtain various types of traffic information and generate intersection exit overflow alarm information; an edge processing center, configured to implement overflow response according to the intersection exit overflow alarm information transmitted by the detection device; a central server, configured to execute the cloud-edge collaborative intersection overflow control method as described above, and communicate with the edge processing center to realize data interaction and instruction issuance; and at least one database, configured to store and process data generated by the interaction with the central server and the edge processing center.

[0207] The edge processing center is the core part of the device, which is specially configured to execute the above-mentioned cloud-edge collaborative intersection overflow control method. This processing center not only has powerful computing capabilities, but also can quickly respond to and process real-time traffic information collected by edge detection devices, thereby ensuring smooth and safe traffic at intersections.

[0208] The central server plays an important role in centralized management and coordination of edge operations. It is closely connected to the edge processing center and realizes real-time data interaction and accurate instruction delivery through an efficient communication network. In addition, the central server also communicates with at least one database, which not only facilitates data storage and retrieval, but also provides a solid foundation for subsequent data analysis and optimization.

[0209] In order to obtain various types of traffic information in real time, the embodiment of the present invention deploys at least one detection device at the edge. These devices can accurately monitor and collect traffic data at intersections, such as vehicle flow, vehicle speed, etc., and provide accurate and timely input information for the edge processing center.

[0210] Finally, the embodiment of the present invention is also equipped with at least one database specifically used to store and process data related to intersection overflow control. These databases not only have huge capacity, but also have efficient data processing and analysis capabilities, providing strong data support for the stable operation of the entire system. Through this cloud-edge collaborative intersection overflow control device, the embodiment of the present invention can achieve precise control of intersection traffic, effectively prevent and solve intersection overflow problems, thereby improving the overall efficiency and safety of urban traffic.

[0211] Furthermore, an embodiment of the present invention provides a computer-readable medium having computer-executable instructions stored thereon, and when the executable instructions are executed by a processor, the method for cloud-edge collaborative intersection overflow control as described above is implemented.

[0212] The embodiment of the present invention further provides a computer-readable medium on which specific computer-executable instructions are stored. When these instructions are executed by the processor, they can implement the aforementioned cloud-edge collaborative intersection overflow control method. Through this design, the embodiment of the present invention not only provides an implementation method for the method, but also enables the method to be conveniently deployed and applied on various computing devices through computer-readable media, thereby effectively promoting and applying cloud-edge collaborative intersection overflow control technology, bringing substantial convenience and benefits to traffic management and control.

[0213] In summary, the embodiments of the present invention provide a cloud-edge collaborative intersection overflow control method, system, device and medium. The general idea is: when the present invention detects overflow, it immediately executes the early disconnection / extension strategy to deal with the overflow alarm in time. The vehicles blocked in the intersection are dissipated through signal timing control, and the flow direction entering and leaving the overflow section is coordinated to be released at the same time. At the same time, the arrival rate and departure rate of vehicles entering and leaving the overflow section are guaranteed to prevent the exit from overflowing again.

[0214] like Figure 8 Specifically, when the downstream intersection of the overflow intersection is controllable, the present invention will take the following steps:

[0215] If the downstream intersection of the overflow intersection is controllable, the overflow alarm of the intersection exit will be received first, and the direction of the overflow exit and the phase of the associated flow direction of the upstream and downstream intersections will be determined. Subsequently, the edge end will implement the overflow response. When the exit overflow is detected, for the downstream intersection, if the associated phase is red, the green light will be started in advance; if it is green, the extension time of the green light will be increased. For the overflow intersection, if the associated phase is red, the red light time will be extended; if it is green, the green light will be early disconnected, and if the next phase is still an associated phase, it will jump to a non-associated phase.

[0216] Next, the signal control schemes for the overflow intersection and the downstream intersection are coordinated, including adjustments in terms of cycle, green-to-signal ratio, and phase difference. At the same time, considering that the increase in the downstream associated phase time may lead to an increase in downstream exit traffic, it will be determined whether the downstream section exit will overflow during the dissipation period, and corresponding measures will be taken to eliminate the impact of the upstream and downstream intersections. Finally, after queuing in the dissipation intersection, the green light time will be adjusted so that the green light time of the associated phase of the downstream intersection decreases second by second, while the green light time of the associated phase of the overflow intersection increases second by second, to ensure that the departure rate of the corresponding section is just greater than or equal to the arrival rate.

[0217] However, when there is no intersection downstream of the overflow intersection or the downstream intersection is uncontrollable: the process will be slightly different. After receiving the intersection exit overflow alarm and determining the overflow exit direction and the associated flow direction, the step of determining the signal operation plan will be entered. When overflow is detected, according to the status of the traffic lights in the associated phase, corresponding measures such as extending the red light time or executing early green light disconnection will be taken. The adjustment time of the green light will then be calculated, and the signal of the upstream intersection will be restored to the original plan after the next cycle dissipates, while the downstream intersection remains unchanged. The downstream intersection will not switch back to the original plan until the flow of each inflow direction of the upstream intersection is detected to have returned to the pre-congestion level, and the algorithm ends at this time.

[0218] It is worth mentioning that if no overflow alarm is received, and empty discharge is detected or there is no overflow after running for 6 cycles, the process ends.

[0219] Since the system / device described in the above embodiments of the present invention is a system / device used to implement the method of the above embodiments of the present invention, a person skilled in the art can understand the specific structure and deformation of the system / device based on the method described in the above embodiments of the present invention, and thus will not be described in detail here. All systems / devices used in the method of the above embodiments of the present invention belong to the scope of protection of the present invention.

[0220] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0221] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0222] It should be noted that in the claims, any reference numerals placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third, etc., is for convenience of expression only and does not indicate any order. These words may be understood as part of the component name.

[0223] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0224] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after knowing the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0225] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include these modifications and variations.

Claims

1. A cloud-edge collaborative intersection overflow control method, characterized in that: include: In response to the intersection exit overflow alarm information, determine the overflow exit direction and the phase of the associated flow direction of the upstream and downstream intersections; According to the overflow response at the edge, the dissipation speed of overflow congestion / aggregation is calculated based on the inflow and outflow flow of the overflow section obtained; Determine the green light adjustment time based on the obtained dissipation speed of overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generate and dynamically adjust the signal control plan of the downstream intersection and / or overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections; After the queue on the overflow section dissipates, the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection is gradually adjusted until the departure rate of the overflow section is not less than the arrival rate, and the original signal control scheme before the dynamic adjustment is restored.

2. The cloud-edge collaborative intersection overflow control method according to claim 1, characterized in that: According to the overflow response at the edge, the dissipation speed of overflow congestion / aggregation is obtained based on the inflow and outflow traffic of the overflow section, including: After the edge end implements overflow response according to the overflow alarm information at the intersection exit, the real-time inflow and outflow flow data of the overflow section are obtained through the detection equipment deployed at the edge end; The acquired real-time inflow traffic data and outflow traffic data are processed to calculate the total inflow traffic and total outflow traffic of the overflow section respectively. The inflow traffic is the sum of the left-turn, straight-ahead, and right-turn inflow traffic of the associated phase flowing into the overflow section, and the outflow traffic is the sum of the left-turn, straight-ahead, and right-turn outflow traffic of the associated phase flowing out of the overflow section. Calculate the congestion build-up / dissipation speed based on the total inflow and outflow data; When overflow is detected at the intersection exit, the overflow response at the edge end includes: The following operations are performed on the downstream intersection: if the associated phase of the downstream intersection is a red light, the associated phase green light is started early; if the associated phase of the downstream intersection is a green light, a green light is added to extend the time; The following operations are performed on the overflow intersection: if the associated phase of the overflow intersection is a red light, the red light time is extended; if the associated phase of the overflow intersection is a green light, the green light is disconnected early; if the next phase is still an associated phase, the phase is jumped to a non-associated phase.

3. The cloud-edge collaborative intersection overflow control method according to claim 1, characterized in that: The green light adjustment time is determined based on the obtained dissipation speed of the overflow congestion / gathering, the preset number of overflow vehicles and the green light time, and the signal control scheme for the downstream intersection and / or the overflow intersection is generated in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections, including: Determine the time required for dissipation based on the dissipation speed of the overflow congestion / agglomeration and the preset number of overflow vehicles; Add a green light at the downstream intersection to extend the time and form a dissipating wave; Allocate the green light extension time to the left-turn and through-travel outflow phases of the downstream intersection according to a set ratio, and calculate the flow rate and the departure rate of the overflow section of the left-turn and through-travel outflow phases of the downstream intersection after allocating the green light extension time, so as to determine the adjusted dissipation speed of overflow congestion / aggregation; With the goal of clearing the queue, the green light time for straight and left turns in the associated phase of the downstream intersection is solved, and the green light extension time of the non-associated phase of the downstream intersection is reduced while keeping the cycle unchanged; If the green light time for straight and left turns in the associated phase of the downstream intersection is the maximum green light time, the maximum green light time for the associated phase of the downstream intersection is configured, and the inflow phase of the overflow intersection is reduced by one green light to shorten the time; Allocate the shortened green light time to the left-turn and through-travel inflow phases of the overflow intersection according to a set ratio, and calculate the flow rate of the left-turn and through-travel inflow phases of the overflow intersection after allocating the shortened green light time and the arrival rate of the overflow section to determine the adjusted dissipation speed of the overflow congestion / aggregation; With the goal of clearing the queue, the green light time for straight and left turns in the associated phases of the overflow intersection is solved, and the green light time for non-associated phases of the overflow intersection is shortened while keeping the cycle unchanged; If the green light times for straight and left turns in the associated phases of the overflow intersection both take the minimum green light time, then configure the maximum green light time for the associated phases of the downstream intersection and the minimum green light time for the associated phases of the overflow intersection, and request manual intervention.

4. The cloud-edge collaborative intersection overflow control method according to claim 1, characterized in that: Dynamically adjust signal control solutions for downstream intersections and / or overflow intersections include: The larger one of the cycles at the overflow intersection and the downstream intersection is selected as the common cycle, and the downstream intersection is determined as the key intersection; The phase with the largest associated flow direction is selected as the coordination phase; Calculate the difference between the end time of the signal control scheme of the overflow intersection and the downstream intersection, and use the obtained difference as the first phase difference of the signal control scheme of the current downstream intersection and / or the overflow intersection; Calculate the coordinated phase difference, and adjust the coordinated phase difference according to the requirements of coordinated control, and then obtain the phase difference change; Configure the overflow intersection and downstream intersection to use the green-to-signal ratio of their original solutions; If the phase difference variation is positive or negative, adjusting the signal control scheme of the downstream intersection and / or the overflow intersection based on the cycle of the overflow intersection, the cycle of the downstream intersection and the phase difference variation; Based on the adjusted signal control scheme of the downstream intersection and / or the overflow intersection, the green light time of the coordinated phase-associated flow direction of the overflow intersection is verified to determine whether the green light time of the coordinated phase-associated flow direction of the overflow intersection is less than or equal to the corresponding green light time of the downstream intersection; If the green light time of the flow direction associated with the coordinated phase of the overflow intersection is not less than or equal to the corresponding green light time of the downstream intersection, the flow direction that exceeds the time is subject to early disconnection processing; in, The phase difference change is: Δt p =min[|t p -t' p |,|T-(t p -t' p )|] Where, t p is the coordination phase difference, t' p is the coordinated phase difference after adjustment, T is the common period; When the phase difference change is greater than 0, adjust the cycle T tran : T tran =min[T1,T2]+Δt p ; When the phase difference change is less than 0, adjust the cycle T tran : T tran =max[T1,T2]+Δt p 。 5. The cloud-edge collaborative intersection overflow control method according to claim 1, characterized in that: The green light adjustment time is determined based on the obtained dissipation speed of the overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and the signal control scheme of the downstream intersection and / or the overflow intersection is generated and dynamically adjusted in combination with the overflow exit direction and the associated flow direction phase of the upstream and downstream intersections. The following also includes: When the green light time of the downstream associated phase increases, monitor whether the dissipation period will cause vehicle overflow at the exit of the downstream section; If the departure rate of the downstream section exit is greater than or equal to the arrival rate, the current signal control scheme will continue to be maintained; If the exit rate of the downstream section exit is less than the arrival rate, determine whether the set overflow judgment condition is met; If the overflow judgment condition is not met, the green light time of the corresponding outflow phase of at least two adjacent sections of the downstream section is increased by accumulating second by second to increase the exit rate of the overflow at the downstream section outlet until the overflow judgment condition is met; After the overflow judgment conditions are met, recalculate and verify whether the capacity of all affected sections is met; The overflow judgment condition is: (g+Δg)·(Q i+1,in -Q i+1,out )≤l i+1 ; In the formula, g is the green light time, Δg is the green light adjustment time, Q i+1,in is the exit rate of the downstream section’s exit overflow, Q i+1,out is the overflow rate at the downstream road exit, l i+1 The number of vehicles queuing on the downstream section.

6. The cloud-edge collaborative intersection overflow control method according to claim 1, characterized in that: After the queue on the overflow section dissipates, the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection is gradually adjusted until the departure rate of the overflow section is not less than the arrival rate. The original signal control scheme before the dynamic adjustment is restored includes: After the queue on the overflow section begins to dissipate, gradually reduce the green light time of the associated phase of the downstream intersection, record the changes in the departure rate and arrival rate of the overflow section after each adjustment, until the departure rate of the overflow section is not less than the arrival rate, and gradually restore the green light time to the original signal control scheme before dynamic adjustment; If the condition that the departure rate is not less than the arrival rate cannot be met by adjusting the associated phase of the downstream intersection alone, the green light time of the associated phase of the overflow intersection is gradually increased simultaneously or separately, and the changes in the departure rate and arrival rate of the overflow section after each adjustment are recorded; By continuously adjusting the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection until the departure rate of the overflow section is no less than the arrival rate, the green light time is gradually restored to the original signal control scheme before the dynamic adjustment.

7. The cloud-edge collaborative intersection overflow control method according to any one of claims 1 to 6, characterized in that: If there is no intersection downstream of the overflow intersection or the downstream intersection is uncontrollable, Receive and transmit the alarm information of the overflow section to the central server to obtain the upstream and downstream road network relationship of the overflow section, and determine the overflow exit direction and the associated flow phase of the upstream and downstream intersections; According to the red or green light status of the associated phase of the overflow intersection, the red light time of the overflow intersection is extended accordingly or the green light is turned off early; Configure the number of overflow vehicles that need to be dissipated immediately, and use the saturated headway to calculate the time required to leave; According to the time required to leave, adjust the green light time of the downstream intersection and the green light time of the upstream intersection; If there is no alarm information of overflow section in the next cycle, the schemes of upstream and downstream intersections will be gradually restored to the original signal control scheme until the traffic volume returns to the pre-congestion level; If there is still alarm information about overflow sections in the next cycle, configure the maximum green light time for the downstream associated phase operation and the minimum green light time for the upstream associated phase operation, and request manual disposal.

8. A cloud-edge collaborative intersection overflow control system, characterized in that: include: A signal determination module, for responding to the overflow alarm information at the intersection exit, determining the overflow exit direction and the phase of the associated flow direction of the upstream and downstream intersections; A dissipation speed output module is used to obtain the dissipation speed of overflow congestion / aggregation based on the overflow response of the edge end and the inflow and outflow flow of the overflow section; A scheme generation and adjustment module is used to determine the green light adjustment time based on the obtained dissipation speed of overflow congestion / aggregation, the preset number of overflow vehicles and the green light time, and generate and dynamically adjust the signal control scheme of the downstream intersection and / or the overflow intersection in combination with the overflow exit direction and the associated flow phase of the upstream and downstream intersections; The scheme callback module is used to gradually adjust the green light time of the associated phase of the downstream intersection and / or the associated phase of the overflow intersection after the queue of the overflow section dissipates, until the departure rate of the overflow section is not less than the arrival rate, and restore to the original signal control scheme before the dynamic adjustment.

9. A cloud-edge collaborative intersection overflow control device, characterized in that: include: At least one detection device, deployed at the edge, configured to obtain various types of traffic information and generate intersection exit overflow alarm information; The edge processing center is configured to implement overflow response according to the intersection exit overflow alarm information transmitted by the detection device; A central server, configured to execute the cloud-edge collaborative intersection overflow control method according to any one of claims 1 to 7, and to communicate with the edge processing center to realize data interaction and instruction issuance; And, at least one database configured to store and process data generated by the interaction with the central server and the edge processing center.

10. A computer-readable medium having computer-executable instructions stored thereon, characterized in that: When the executable instructions are executed by the processor, the cloud-edge collaborative intersection overflow control method as described in any one of claims 1-7 is implemented.

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