Traffic light signal timing optimization method and system at road intersection

Abstract

The present invention discloses a signal timing optimization method and system for traffic lights at road intersections, which obtain vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection; determine whether the current traffic flow generates a gathering wave scenario; if a gathering wave scenario is generated, determine whether the gathering wave scenario is generated after a set time range from the moment when the green light is turned on, or is generated at the moment when the green light is turned on; if it is the former, determine the first phase difference of the traffic light according to the acquired data; if it is the latter, determine the second phase difference of the traffic light according to the acquired data; if no gathering wave scenario is generated, determine the third phase difference of the traffic light according to the acquired data; and re-time the traffic light at the current road intersection according to the determined first phase difference of the traffic light, the second phase difference of the traffic light, or the third phase difference of the traffic light, and output the re-timing result.

Description

Technical Field

[0001] The present invention relates to the field of intelligent transportation technology, and in particular to a method and system for optimizing the timing of traffic light signals at road intersections. Background Art

[0002] The statements in this section merely mention background art related to the present invention and do not necessarily constitute prior art.

[0003] Due to the rapid economic development, the continuous expansion of urban scale, the increase in the use of cars, the disadvantages of traditional traffic lights have gradually emerged, and the problem of urban congestion has become more and more serious. Urban congestion will not only lead to the decline of various economic and social functions, but also cause the continuous deterioration of the urban living environment, becoming an "urban disease" that hinders development. The most direct impact of urban congestion on social life is the increase in residents' travel time and cost. The increase in travel costs not only affects work efficiency, but also inhibits people's daily activities, greatly reduces urban vitality, and the quality of life of residents also declines. In addition, urban congestion has also led to an increase in accidents, and the increase in accidents has exacerbated congestion.

[0004] At present, the traffic flow distribution at urban road intersections is uneven, the arrival is highly random, and the traffic is complex and changeable. Therefore, a reasonable phase of traffic lights at intersections is particularly important. The main purpose of the phase of traffic lights at intersections is to properly separate traffic flows that conflict with each other or interfere with each other, and reduce traffic conflicts and interference at intersections. The phase design of traffic lights is a key step in signal timing, which determines the scientificity and rationality of the timing plan and directly affects the traffic safety and smoothness of road intersections. Phase design should improve the utilization of time and space resources at intersections. Too many phases will lead to an increase in lost time, thereby reducing the traffic capacity and traffic efficiency of the intersection; too few phases will reduce efficiency due to serious conflicts. Therefore, a reasonable intersection phase difference is the key to improving the operating efficiency of urban intersections. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the present invention provides a method and system for optimizing the timing of traffic light signals at road intersections; the timing can be scientifically and reasonably coordinated, the operating efficiency can be improved, the traffic safety can be guaranteed, and the quality of life of residents can be improved.

[0006] In a first aspect, the present invention provides a method for optimizing the timing of traffic light signals at road intersections;

[0007] The signal timing optimization method of traffic lights at road intersections includes:

[0008] In response to the traffic signal retiming instruction, obtaining vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection;

[0009] Determine whether the current traffic flow generates a gathering wave scenario;

[0010] If a gathering wave scenario is generated, it is determined whether the gathering wave scenario is generated after the set time range from the moment the green light comes on, or when the green light comes on;

[0011] If it is generated after the set time range from the moment the green light turns on, determining the first phase difference of the traffic light according to the acquired data;

[0012] If it is generated when the green light is on, determining the second phase difference of the traffic light according to the acquired data;

[0013] If the gathering wave scenario is not generated, determining a third phase difference of the traffic light according to the acquired data;

[0014] The traffic lights at the current road intersection are re-timed according to the determined first phase difference of the traffic lights, the second phase difference of the traffic lights or the third phase difference of the traffic lights, and the re-timing result is output.

[0015] In a second aspect, the present invention provides a traffic light signal timing optimization system for a road intersection;

[0016] Traffic light signal timing optimization system at road intersections, including:

[0017] An acquisition module, configured to: in response to a traffic signal retiming instruction, acquire vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection;

[0018] A first judgment module is configured to: judge whether the current traffic flow generates a gathering wave scenario, if yes, enter the second judgment module; if no, enter the third judgment module;

[0019] The second judgment module is configured to: judge whether the gathering wave scene is generated after a set time range from the green light on time, or is generated at the green light on time;

[0020] If it is generated after the set time range from the moment the green light turns on, determining the first phase difference of the traffic light according to the acquired data;

[0021] If it is generated when the green light is on, determining the second phase difference of the traffic light according to the acquired data;

[0022] A third judgment module is configured to: if no gathering wave scene is generated, determine a third phase difference of the traffic light according to the acquired data;

[0023] The output module is configured to re-time the traffic lights at the current road intersection according to the determined first phase difference of the traffic lights, the second phase difference of the traffic lights or the third phase difference of the traffic lights, and output the re-timing result.

[0024] In a third aspect, the present invention further provides an electronic device, comprising:

[0025] a memory for non-transitory storage of computer-readable instructions; and

[0026] a processor for executing the computer readable instructions,

[0027] When the computer-readable instructions are executed by the processor, the method described in the first aspect is executed.

[0028] In a fourth aspect, the present invention further provides a storage medium that non-temporarily stores computer-readable instructions, wherein when the non-temporary computer-readable instructions are executed by a computer, the instructions of the method described in the first aspect are executed.

[0029] In a fifth aspect, the present invention further provides a computer program product, comprising a computer program, wherein the computer program is used to implement the method described in the first aspect when running on one or more processors.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention can scientifically and reasonably coordinate time, improve operation efficiency, ensure traffic safety, and improve the quality of life of residents. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 The calculation process of generating a gathering wave scene after the green light turns on in the first embodiment;

[0034] Figure 2 The calculation process of generating a gathering wave scene when the green light is on in the first embodiment;

[0035] Figure 3 This is the calculation process of the scenario in which no gathering wave is generated in the first embodiment. DETAILED DESCRIPTION

[0036] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0037] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0039] In this embodiment, all data is obtained in compliance with laws and regulations and based on the user's consent, and is used legally.

[0040] Embodiment 1

[0041] This embodiment provides a method for optimizing the timing of traffic light signals at road intersections;

[0042] The signal timing optimization method of traffic lights at road intersections includes:

[0043] S101: In response to a traffic signal retiming instruction, obtaining vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection;

[0044] S102: Determine whether the current traffic flow generates a gathering wave scenario, if yes, proceed to S103; if no, proceed to S104;

[0045] S103: Determine whether the gathering wave scene is generated after a set time range from the moment the green light turns on, or is generated at the moment the green light turns on;

[0046] If it is generated after the set time range from the moment the green light turns on, determining the first phase difference of the traffic light according to the acquired data;

[0047] If it is generated when the green light is on, determining the second phase difference of the traffic light according to the acquired data;

[0048] S104: If no gathering wave scenario is generated, determining a third phase difference of the traffic light according to the acquired data;

[0049] S105: re-timing the traffic lights at the current road intersection according to the determined first phase difference of the traffic lights, the second phase difference of the traffic lights, or the third phase difference of the traffic lights, and outputting the re-timing result.

[0050] Figure 1 The calculation process of generating the gathering wave scenario after the green light comes on; Figure 2 The calculation process for generating the rally wave scenario when the green light comes on; Figure 3 This is the calculation process for the scenario where no gathering wave is generated;

[0051] Furthermore, the obtaining of vehicle traffic data of the current road intersection and vehicle traffic data of the previous road intersection specifically includes:

[0052] The length of the road section L, the length of the vehicle queue before the green light comes on L1, the initial phase difference T0 of the current intersection, the start time t1 of the vehicle queue before the green light comes on, the non-assembly time period t3 after the green light comes on, and the assembly wave speed V 集 , Green Wave Speed ​​V 绿 , Average speed of queue clearing V 平 .

[0053] The aggregate wave velocity is acquired through the camera at the road intersection.

[0054] Furthermore, the step S102: determining whether the current traffic flow generates a gathering wave scenario specifically includes:

[0055] The camera captures images of vehicle flow on the road, identifies the images, and determines whether the current traffic flow produces a gathering wave scenario.

[0056] It should be understood that the vehicles traveling in a queue slow down at the entrance of the bottleneck section and queue up one after another to form a high-density queue. The traffic wave formed is called a gathering wave.

[0057] Furthermore, the step S103: determining that the gathering wave scene is generated after a set time range from the moment the green light turns on, where the set time range can be randomly set according to demand, for example, set to 10 seconds or 15 seconds.

[0058] Furthermore, if the phase difference is generated after a set time range from the green light on time, determining the first phase difference of the traffic light according to the acquired data specifically includes:

[0059] S103-a1: Calculate the starting wave speed;

[0060] S103-a2: Calculate the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on, based on the starting wave speed;

[0061] S103-a3: Determine the length of the assembly queue after the green light comes on based on the speed of the starting wave and the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on;

[0062] S103-a4: Determine the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light comes on; calculate the time for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light comes on; determine the maximum phase difference of the previous road intersection according to the time for vehicles to dissipate in the dynamic queue length;

[0063] S103-a5: Determine a first phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase difference at the previous road intersection.

[0064] Furthermore, the step S103-a1: calculating the starting wave velocity specifically includes:

[0065] Starting wave speed V 启 , find the formula:

[0066]

[0067] Among them, L1 represents the length of the vehicle queue before the green light comes on, and t1 represents the starting time of the vehicle queue before the green light comes on.

[0068] Furthermore, the step S103-a2: calculating the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on, according to the starting wave speed, specifically includes:

[0069] The time difference t2 between the moment when the start wave meets the assembly wave and the moment when the start wave reaches the end of the queue before the green light comes on is obtained by the formula:

[0070] V 启 t2=V 集 (t1-t3)+t2V 集 ; (1-2)

[0071]

[0072] Substituting formula (1-1) into the above formula, we can get formula (1-3):

[0073]

[0074] Among them, V 集 represents the velocity of the gathering wave, V 启It represents the starting wave speed, t1 represents the starting time of the vehicle queue before the green light comes on, t3 represents the non-assembly time after the green light comes on, and L1 represents the length of the vehicle queue before the green light comes on.

[0075] Further, the step S103-a3: determining the length of the assembled queue after the green light comes on according to the starting wave speed and the time difference between the moment when the starting wave meets the assembled wave and the moment when the starting wave reaches the end of the queue before the green light comes on, specifically includes:

[0076] The length of the assembly queue after the green light comes on is L2:

[0077] L2=t2×Vstart;(1-5)

[0078]

[0079]

[0080] Among them, V 集 represents the velocity of the gathering wave, V 启 represents the starting wave speed, t1 represents the starting time of the vehicle queue before the green light comes on, t2 represents the time difference between the time when the starting wave meets the assembly wave and the time when the starting wave reaches the end of the queue before the green light comes on, t3 represents the non-assembly time period after the green light comes on, and L1 represents the length of the vehicle queue before the green light comes on.

[0081] Furthermore, the step S103-a4: determining the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light is on, specifically includes:

[0082] T1: The minimum phase difference of the upstream intersection T1min is used to ensure that when the upstream vehicle arrives at the end of the queue, the start wave just propagates to the end of the queue, and the straight-going vehicles at the previous intersection do not queue;

[0083]

[0084] Among them, t1 represents the start time of the vehicle queue before the green light comes on, t2 represents the time difference between the time when the starting wave meets the assembly wave and the time when the starting wave reaches the end of the queue before the green light comes on, L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the assembly queue after the green light comes on, L represents the length of the road section, T0 represents the initial phase difference of the current intersection, V 绿 Indicates the green wave speed;

[0085] Substituting formula (1-4) and (1-7) into formula (1-8), we can obtain:

[0086]

[0087] Among them, T0 represents the initial phase difference of the current intersection, t1 represents the time when the vehicles start queuing before the green light comes on, t3 represents the time when the vehicles are not assembled after the green light comes on, and V 绿 Indicates the green wave speed, V 集 represents the speed of the assembly wave, L represents the length of the road section, and L1 represents the length of the vehicle queue before the green light comes on.

[0088] Further, the method of calculating the time for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light is on; and determining the maximum phase difference of the previous road intersection according to the time for vehicles to dissipate in the dynamic queue length, specifically includes:

[0089] Dynamic queue length Vehicle dissipation time t4:

[0090]

[0091] Among them, L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the assembly queue after the green light comes on, and V 平 It indicates the average speed at which the queue is cleared;

[0092] The formula for calculating the maximum value of the phase difference T1 at the upstream intersection is:

[0093] The maximum value of T1 is used to ensure that when the last car in the queue reaches the stop line, the upstream car also reaches the stop line, so there is no green light time loss;

[0094]

[0095] Among them, T0 represents the initial phase difference of the current intersection, t1 represents the start time of the vehicle queue before the green light comes on, t2 represents the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on, t4 represents the time length of the dynamic queue length, L represents the length of the road section, V 绿 Indicates the green wave speed;

[0096] Substituting formula (1-7) and (1-10) into formula (1-11), we get:

[0097]

[0098] Among them, T0 represents the initial phase difference of the current intersection, t1 represents the time when the vehicles start queuing before the green light comes on, t3 represents the time when the vehicles are not assembled after the green light comes on, and V 绿 Indicates the green wave speed, V 集 represents the velocity of the gathering wave, V 平 It represents the average speed at which vehicles in the queue are cleared, L represents the length of the road section, L1 represents the length of the vehicle queue before the green light comes on, and L2 represents the length of the assembled queue after the green light comes on.

[0099] It should be understood that the lost green time refers to the green time that cannot be effectively utilized by vehicles. The lost green time includes the starting delay time of the front-row vehicles at the start of the green signal at the intersection and the lost time of vehicle deceleration and stopping during the yellow light after the green light ends. Without lost green time, vehicles can effectively utilize the green time.

[0100] Further, in step S103-a5: determining the first phase difference of the traffic signal according to the minimum and maximum values of the forward and reverse two-way phase differences of the previous road intersection specifically includes:

[0101] The value range of the phase difference T obtained for the forward and reverse two-way lanes:

[0102] The value range of T should be greater than the larger value of the forward and reverse T1min and less than the smaller value of the forward and reverse T1max;

[0103] max(forward T1min, reverse T1min) < T < min(forward T1max, reverse T1max).

[0104] Wherein, the forward T1min represents the minimum value of the phase difference of the upstream intersection of the forward lane, the forward T1max represents the maximum value of the phase difference of the upstream intersection of the forward lane; the reverse T1min represents the minimum value of the phase difference of the upstream intersection of the reverse lane, and the reverse T1max represents the maximum value of the phase difference of the upstream intersection of the reverse lane.

[0105] Further, if it is generated at the moment when the green light is on, then determining the second phase difference of the traffic signal according to the obtained data specifically includes:

[0106] S103-b1: calculating the starting wave speed;

[0107] S103-b2: according to the starting wave speed, calculating the time difference between the moment when the starting wave and the gathering wave meet and the moment when the starting wave reaches the end of the queue before the green light is on;

[0108] S103-b3: according to the starting wave speed and the time difference between the moment when the starting wave and the gathering wave meet and the moment when the starting wave reaches the end of the queue before the green light is on, determining the length of the gathering queue after the green light is on;

[0109] S103-b4: according to the length of the gathering queue after the green light is on, determining the minimum value of the phase difference of the previous road intersection; according to the length of the gathering queue after the green light is on, calculating the dissipation time of the dynamic queue length of the vehicle; according to the dissipation time of the dynamic queue length of the vehicle, determining the maximum value of the phase difference of the previous road intersection;

[0110] S103-b5: determining the second phase difference of the traffic signal according to the minimum and maximum values of the forward and reverse two-way phase differences of the previous road intersection.

[0111] Furthermore, the step S103-b1: calculating the starting wave velocity specifically includes:

[0112] Starting wave speed V 启 Find the formula:

[0113]

[0114] Wherein: L1 represents the length of the vehicle queue before the green light comes on, and t1 represents the start time of the vehicle queue before the green light comes on.

[0115] Furthermore, the step S103-b2: calculating the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on, according to the starting wave speed, specifically includes:

[0116] The formula for calculating t2 time is:

[0117] V 启 t2=V 集 t1+t2V 集 ; (2-2)

[0118] Where: V 集 represents the velocity of the gathering wave, V 启 represents the speed of the starting wave, t1 represents the time when the vehicles queue up before the green light comes on, and t2 represents the time difference between the time when the starting wave meets the assembly wave and the time when the starting wave reaches the end of the queue before the green light comes on;

[0119] Substituting formula (2-1) into formula (2-2) yields formula (2-3):

[0120]

[0121] Where: V 集 It represents the speed of the assembly wave, t1 represents the starting time of the vehicle queue before the green light comes on, and L1 represents the length of the vehicle queue before the green light comes on.

[0122] Further, the step S103-b3: determining the length of the assembled queue after the green light comes on according to the starting wave speed and the time difference between the moment when the starting wave meets the assembled wave and the moment when the starting wave reaches the end of the queue before the green light comes on, specifically includes:

[0123] The length of the assembly queue after the green light comes on is L2:

[0124] L2=t2×V 启 ; (2-4)

[0125]

[0126]

[0127] Among them: t1 represents the time when the vehicles start queuing before the green light comes on, t2 represents the time difference between the time when the starting wave meets the assembly wave and the time when the starting wave reaches the end of the queue before the green light comes on, V 集 represents the velocity of the gathering wave, V 启 It indicates the starting wave speed, and L1 indicates the length of the vehicle queue before the green light comes on.

[0128] Furthermore, the step S103-b4: determining the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light is on, specifically includes:

[0129] The minimum value of T1 ensures that when the upstream vehicle arrives at the end of the queue, the start wave just propagates to the end of the queue, and the straight vehicles at the upstream intersection cannot form a queue. The formula for calculating the minimum value of T1 is:

[0130]

[0131] Where: T0 represents the initial phase difference of the current intersection, t1 represents the start time of the vehicle queue before the green light comes on, t2 represents the time difference between the moment when the start wave meets the assembly wave and the moment when the start wave reaches the end of the queue before the green light comes on, L represents the length of the road section, L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the assembly queue after the green light comes on, V 绿 Indicates the green wave speed.

[0132] Substituting formula (2-3) and (2-6) into the above formula, we can get:

[0133]

[0134] Where: T0 represents the initial phase difference of the current intersection, t1 represents the start time of the vehicle queue before the green light comes on, L represents the length of the road section, L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the vehicle queue after the green light comes on, V 集 represents the velocity of the gathering wave, V 绿 Indicates the green wave speed.

[0135] Further, the method of calculating the time for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light is on; and determining the maximum phase difference of the previous road intersection according to the time for vehicles to dissipate in the dynamic queue length, specifically includes:

[0136] Dynamic queue length Vehicle dissipation time t4:

[0137]

[0138] Where: L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the assembly queue after the green light comes on, V 平 It indicates the average speed at which the queue is cleared;

[0139] Formula for calculating the maximum value of T1:

[0140] The minimum value of T1 needs to ensure that when the upstream vehicle arrives at the end of the queue, the starting wave just propagates to the end of the queue, and the straight-through vehicles from the upstream intersection cannot form a queue.

[0141]

[0142] Where: T0 represents the initial phase difference of the current intersection, t1 represents the starting time of vehicle queuing before the green light comes on, t2 represents the time difference between the moment when the starting wave meets the agglomeration wave and the moment when the starting wave reaches the end of the queue before the green light comes on, t4 represents the dissipation time of the vehicles in the dynamic queue length, L represents the road section length, and V 绿 represents the green wave speed;

[0143] Substituting formulas (2-3) and (2-9) into (2-10), we can get:

[0144]

[0145] Where: T0 represents the initial phase difference of the current intersection, t1 represents the starting time of vehicle queuing before the green light comes on, L represents the road section length, L1 represents the vehicle queuing length before the green light comes on, L2 represents the agglomeration queuing length after the green light comes on, and V 绿 represents the green wave speed, and V 平 represents the average speed of clearing the queuing vehicles, and V 集 represents the agglomeration wave speed.

[0146] Furthermore, in step S103-b5: determining the second phase difference of the traffic signal according to the minimum and maximum values of the forward and reverse phase differences of the previous road intersection, specifically including:

[0147] Range of values for the phase difference T obtained by forward and reverse directions:

[0148] The range of values of T should be greater than the larger value of T1min in the forward and reverse lanes and less than the smaller value of T1max in the forward and reverse lanes.

[0149] max(forward T1min, reverse T1min) < T < min(forward T1max, reverse T1max).

[0150] Where: forward T1min represents the minimum value of the phase difference of the upstream intersection in the forward lane, and forward T1max represents the maximum value of the phase difference of the upstream intersection in the forward lane.

[0151] Furthermore, if no agglomeration wave scenario occurs, then determine the third phase difference of the traffic signal according to the acquired data, specifically including:

[0152] S104-1: Calculate the dissipation time of the vehicles in the dynamic queue length;

[0153] S104-2: Determine the minimum phase difference of the previous road intersection;

[0154] S104-3: Determine the maximum phase difference of the previous road intersection according to the time it takes for the vehicles in the dynamic queue to dissipate;

[0155] S104-4: Determine a second phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase difference at the previous road intersection.

[0156] Furthermore, the step S104-1: calculating the dynamic queue length vehicle dissipation time specifically includes:

[0157] Dynamic queue length Vehicle dissipation time t4:

[0158]

[0159] Where: L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the assembly queue after the green light comes on, V 平 Indicates the average speed at which vehicles in a queue are cleared.

[0160] Furthermore, the step S104-2: determining the minimum phase difference of the previous road intersection specifically includes:

[0161] The formula for obtaining the minimum value of T1 is:

[0162] The minimum value of T1 needs to ensure that when the upstream vehicle reaches the end of the queue, the starting wave just propagates to the end of the queue, and the straight vehicles coming from the upstream intersection cannot form a queue.

[0163]

[0164] Where: T0 represents the initial phase difference of the current intersection, t1 represents the start time of the vehicle queue before the green light comes on, L represents the length of the road section, L1 represents the length of the vehicle queue before the green light comes on, L2 represents the length of the vehicle queue after the green light comes on, V 绿 Indicates the green wave speed.

[0165] Furthermore, the step S104-3: determining the maximum phase difference of the previous road intersection according to the dynamic queue length vehicle dissipation time specifically includes:

[0166] The formula for calculating the maximum value of T1 is:

[0167] The minimum value of T1 needs to ensure that when the upstream vehicle reaches the end of the queue, the starting wave just propagates to the end of the queue, and the straight vehicles coming from the upstream intersection cannot form a queue.

[0168]

[0169] Wherein: T0 represents the initial phase difference of the current intersection, t1 represents the starting moment of vehicle queuing before the green light comes on, t4 represents the dissipation duration of the dynamic queuing length of vehicles, L represents the road section length, and V 绿 represents the green wave speed;

[0170] Substituting formula (3-1) into the above formula, we can get:

[0171]

[0172] Wherein: T0 represents the initial phase difference of the current intersection, t1 represents the starting moment of vehicle queuing before the green light comes on, L represents the road section length, L1 represents the vehicle queuing length before the green light comes on, L2 represents the aggregated queuing length after the green light comes on, and V 绿 represents the green wave speed, and V 平 represents the average speed for clearing queuing vehicles.

[0173] Further, the step S104-4: determining the second phase difference of the traffic signal according to the minimum and maximum values of the forward and reverse phase differences of the previous road intersection, specifically includes:

[0174] Obtaining the value range of the phase difference T in the forward and reverse directions:

[0175] The value range of T should be greater than the larger value of T1min in the forward and reverse lanes and less than the smaller value of T1max in the forward and reverse directions.

[0176] max(forward T1min, reverse T1min) < T < min(forward T1max, reverse T1max).

[0177] Wherein: forward T1min represents the minimum value of the phase difference of the upstream intersection of the forward lane, forward T1max represents the maximum value of the phase difference of the upstream intersection of the forward lane; reverse T1min represents the minimum value of the phase difference of the upstream intersection of the reverse lane, and reverse T1max represents the maximum value of the phase difference of the upstream intersection of the reverse lane.

[0178] Further, re-timing the traffic signal of the current road intersection according to the determined first phase difference, second phase difference or third phase difference of the traffic signal. It should be understood that the phase of the traffic signal refers to the time given for the corresponding release of traffic flows in different directions. The phase difference of the traffic signal refers to the time difference between the release phases in the same direction at adjacent intersections.

[0179] The present invention mainly calculates the algorithm of the intersection phase difference according to the relationship between the queuing length at the intersection when the green light starts, the vehicle platoon starting wave speed, the subsequent vehicle aggregation queuing, and the green wave speed.

[0180] The indicators involved can be divided into two categories: detection indicators and calculation indicators. The calculated target value is the value range of T1.

[0181] Use an infrared measuring instrument to measure the actual length of the center line of the highway from the current road intersection to the previous road intersection, that is, the length of the road section L. Install an infrared sensing device under the ground of the road section along the direction of the road section. The device can sense the distance from the front of the first car that stops before a green light in a lane to the rear of the last car that stops when the green light just comes on, that is, the queue length L1 before the green light comes on. Determine the relative phase difference of adjacent intersections. According to the actual driving of the vehicle to follow the traffic flow, record the time of passing each intersection respectively, and remove the parking time and the influence of the queued vehicles, the phase difference T0 of the current intersection can be calculated. The queue start time t1 before the green light comes on and the unassembled time t2 after the green light comes on can be directly obtained.

[0182] Embodiment 2

[0183] This embodiment provides a traffic light signal timing optimization system for a road intersection;

[0184] Traffic light signal timing optimization system at road intersections, including:

[0185] An acquisition module, configured to: in response to a traffic signal retiming instruction, acquire vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection;

[0186] A first judgment module is configured to: judge whether the current traffic flow generates a gathering wave scenario, if yes, enter the second judgment module; if no, enter the third judgment module;

[0187] The second judgment module is configured to: judge whether the gathering wave scene is generated after a set time range from the green light on time, or is generated at the green light on time;

[0188] If it is generated after the set time range from the moment the green light turns on, determining the first phase difference of the traffic light according to the acquired data;

[0189] If it is generated when the green light is on, determining the second phase difference of the traffic light according to the acquired data;

[0190] A third judgment module is configured to: if no gathering wave scene is generated, determine a third phase difference of the traffic light according to the acquired data;

[0191] The output module is configured to re-time the traffic lights at the current road intersection according to the determined first phase difference of the traffic lights, the second phase difference of the traffic lights or the third phase difference of the traffic lights, and output the re-timing result.

[0192] It should be noted that the acquisition module, the first judgment module, the second judgment module, the third judgment module and the output module correspond to steps S101 to S105 in Embodiment 1, and the examples and application scenarios implemented by the modules and the corresponding steps are the same, but are not limited to the contents disclosed in Embodiment 1. It should be noted that the modules as part of the system can be executed in a computer system such as a set of computer executable instructions.

[0193] The description of each embodiment in the above embodiments has different emphases. For parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0194] The proposed system can be implemented in other ways. For example, the system embodiment described above is only illustrative, and the division of the modules is only a logical function division. In actual implementation, there may be other division methods, such as multiple modules can be combined or integrated into another system, or some features can be ignored or not executed.

[0195] Embodiment 3

[0196] This embodiment also provides an electronic device, including: one or more processors, one or more memories, and one or more computer programs; wherein the processor is connected to the memory, and the one or more computer programs are stored in the memory. When the electronic device is running, the processor executes the one or more computer programs stored in the memory so that the electronic device executes the method described in the above embodiment one.

[0197] It should be understood that in this embodiment, the processor may be a central processing unit CPU, and the processor may also be other general-purpose processors, digital signal processors DSP, application-specific integrated circuits ASIC, off-the-shelf programmable gate arrays FPGA or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0198] The memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0199] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software.

[0200] The method in the first embodiment can be directly embodied as a hardware processor, or a combination of hardware and software modules in the processor. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0201] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with this embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0202] Embodiment 4

[0203] This embodiment further provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, the method described in the first embodiment is completed.

[0204] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for optimizing the timing of traffic lights at road intersections, characterized in that: include: In response to the traffic signal retiming instruction, obtaining vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection; Determine whether the current traffic flow generates a gathering wave scenario; If a gathering wave scenario is generated, it is determined whether the gathering wave scenario is generated after the set time range from the moment the green light comes on, or when the green light comes on; If the phase difference is generated after the set time range from the green light on time, the first phase difference of the traffic light is determined according to the acquired data, specifically including: Step (11): Calculate the starting wave velocity; Step (12): Based on the starting wave speed, calculate the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on; Step (13): Determine the length of the assembly queue after the green light comes on based on the speed of the starting wave and the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on; Step (14): Determine the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light comes on; calculate the time it takes for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light comes on; determine the maximum phase difference of the previous road intersection according to the time it takes for vehicles to dissipate in the dynamic queue length; Step (15): determining a first phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase differences at the previous road intersection; If it is generated when the green light is on, the second phase difference of the traffic light is determined according to the acquired data, specifically including: Step (21): Calculate the starting wave velocity; Step (22): Calculate the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on, based on the starting wave speed; Step (23): Determine the length of the assembly queue after the green light comes on based on the speed of the starting wave and the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on; Step (24): Determine the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light comes on; calculate the time it takes for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light comes on; and determine the maximum phase difference of the previous road intersection according to the time it takes for vehicles to dissipate in the dynamic queue length; Step (25): determining a second phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase difference at the previous road intersection; If the gathering wave scenario is not generated, the third phase difference of the traffic light is determined according to the acquired data, specifically including: Step (31): Calculate the dynamic queue length and the time it takes for vehicles to disappear; Step (32): Determine the minimum phase difference of the previous road intersection; Step (33): Determine the maximum phase difference of the previous road intersection according to the dynamic queue length and the time it takes for vehicles to dissipate; Step (34): determining a third phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase differences at the previous road intersection; The traffic lights at the current road intersection are re-timed according to the determined first phase difference of the traffic lights, the second phase difference of the traffic lights or the third phase difference of the traffic lights, and the re-timing result is output.

2. The method for optimizing the timing of traffic lights at road intersections as claimed in claim 1, characterized in that: In the step (14), the time it takes for vehicles in the dynamic queue to dissipate is calculated based on the length of the assembled queue after the green light comes on; According to the dynamic queue length vehicle dissipation time, determine the maximum phase difference of the previous road intersection, including: Dynamic queue length Vehicle dissipation time : ；（1-10） in, Indicates the length of the vehicle queue before the green light comes on. Indicates the length of the assembly queue after the green light comes on. It indicates the average speed at which the queue is cleared; The maximum value formula is: The maximum value is used to ensure that when the last car in the queue reaches the stop line, the upstream car also reaches the stop line, so there is no green light time loss; max= + + + ;(1-11) in, Indicates the initial phase difference of the current intersection, Indicates the time when the vehicle queue starts before the green light comes on. It represents the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on. The dynamic queue length is the time it takes for vehicles to dissipate, L is the length of the road section, Indicates the green wave speed; Substituting formula (1-10) into formula (1-11) yields: max= + + + ;(1-12) in, Indicates the initial phase difference of the current intersection, Indicates the time when the vehicle queue starts before the green light comes on. Indicates the time when the green light comes on but no assembly is done. represents the green wave speed, represents the gathering wave velocity, represents the average speed at which queued vehicles are cleared, L represents the length of the road section, Indicates the length of the vehicle queue before the green light comes on. Indicates the length of the assembly queue after the green light comes on.

3. The method for optimizing the timing of traffic lights at road intersections as claimed in claim 1, characterized in that: In the step (24), the time it takes for vehicles in the dynamic queue to dissipate is calculated based on the length of the assembled queue after the green light comes on; According to the dynamic queue length vehicle dissipation time, determine the maximum phase difference of the previous road intersection, including: Dynamic queue length Vehicle dissipation time : ；（2-9） in: Indicates the length of the vehicle queue before the green light comes on. Indicates the length of the assembly queue after the green light comes on. It indicates the average speed at which the queue is cleared; The maximum value formula is: The minimum value needs to ensure that when the upstream vehicle arrives at the end of the queue, the start wave just propagates to the end of the queue, and the straight vehicles at the upstream intersection cannot form a queue; max= + + + ;(2-10) in: Indicates the initial phase difference of the current intersection, Indicates the time when the vehicle queue starts before the green light comes on. It represents the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on. The dynamic queue length is the time it takes for vehicles to dissipate, L is the length of the road section, Indicates the green wave speed; Substituting formula (2-9) into (2-10) yields: max= + + + ;(2-11) in: Indicates the initial phase difference of the current intersection, It indicates the time when the vehicles start queuing before the green light comes on, L indicates the length of the road section, Indicates the length of the vehicle queue before the green light comes on. Indicates the length of the assembly queue after the green light comes on. represents the green wave speed, represents the average speed at which the queue is cleared. represents the gathering wave velocity.

4. The method for optimizing the timing of traffic lights at road intersections as claimed in claim 1, characterized in that: The calculation of the dynamic queue length vehicle dissipation time in step (31) specifically includes: Dynamic queue length Vehicle dissipation time : ；（3-1） in: Indicates the length of the vehicle queue before the green light comes on. Indicates the length of the assembly queue after the green light comes on. It indicates the average speed at which the queue is cleared; According to the dynamic queue length vehicle dissipation time, determine the maximum phase difference of the previous road intersection, including: The maximum value formula is: The minimum value needs to ensure that when the upstream vehicle arrives at the end of the queue, the start wave just propagates to the end of the queue, and the straight vehicles at the upstream intersection cannot form a queue; max= + + in: Indicates the initial phase difference of the current intersection, Indicates the time when the vehicle queue starts before the green light comes on. The dynamic queue length is the time it takes for vehicles to dissipate, L is the length of the road section, Indicates the green wave speed; Substituting formula (3-1) into the above formula, we can get: max= + + in: Indicates the initial phase difference of the current intersection, It indicates the time when the vehicles start queuing before the green light comes on, L indicates the length of the road section, Indicates the length of the vehicle queue before the green light comes on. Indicates the length of the assembly queue after the green light comes on. represents the green wave speed, It indicates the average speed at which the queue is cleared; According to the minimum and maximum values ​​of the forward and reverse bidirectional phase differences of the previous road intersection, the third phase difference of the traffic light is determined, specifically including: Obtain phase difference in both positive and negative directions The value range of is: The value range should be larger than the forward and reverse two-way lanes The maximum value of min should be smaller than the positive and negative bidirectional values. Small value of max; max(positive min, reverse min)< < min(positive max, reverse max); Among them: forward min represents the minimum phase difference of the upstream intersection of the positive lane. max indicates the maximum phase difference of the upstream intersection of the forward lane; min represents the minimum phase difference of the upstream intersection of the reverse lane. max represents the maximum phase difference of the upstream intersection of the reverse lane.

5. A traffic light signal timing optimization system at a road intersection, characterized in that: include: An acquisition module, configured to: in response to a traffic signal retiming instruction, acquire vehicle traffic data of a current road intersection and vehicle traffic data of a previous road intersection; A first judgment module is configured to: judge whether the current traffic flow generates a gathering wave scenario, if yes, enter the second judgment module; if no, enter the third judgment module; The second judgment module is configured to: judge whether the gathering wave scene is generated after a set time range from the green light on time, or is generated at the green light on time; If the phase difference is generated after the set time range from the green light on time, the first phase difference of the traffic light is determined according to the acquired data, specifically including: Step (11): Calculate the starting wave velocity; Step (12): Based on the starting wave speed, calculate the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on; Step (13): Determine the length of the assembly queue after the green light comes on based on the speed of the starting wave and the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on; Step (14): Determine the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light comes on; calculate the time it takes for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light comes on; determine the maximum phase difference of the previous road intersection according to the time it takes for vehicles to dissipate in the dynamic queue length; Step (15): determining a first phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase differences at the previous road intersection; If it is generated when the green light is on, the second phase difference of the traffic light is determined according to the acquired data, specifically including: Step (21): Calculate the starting wave velocity; Step (22): Calculate the time difference between the moment when the starting wave meets the gathering wave and the moment when the starting wave reaches the end of the queue before the green light comes on, based on the starting wave speed; Step (23): Determine the length of the assembly queue after the green light comes on based on the speed of the starting wave and the time difference between the moment when the starting wave meets the assembly wave and the moment when the starting wave reaches the end of the queue before the green light comes on; Step (24): Determine the minimum phase difference of the previous road intersection according to the length of the assembled queue after the green light comes on; calculate the time it takes for vehicles to dissipate in the dynamic queue length according to the length of the assembled queue after the green light comes on; and determine the maximum phase difference of the previous road intersection according to the time it takes for vehicles to dissipate in the dynamic queue length; Step (25): determining a second phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase difference at the previous road intersection; The third judgment module is configured to: if no gathering wave scene is generated, determine the third phase difference of the traffic light according to the acquired data, specifically including: Step (31): Calculate the dynamic queue length and the time it takes for vehicles to disappear; Step (32): Determine the minimum phase difference of the previous road intersection; Step (33): Determine the maximum phase difference of the previous road intersection according to the dynamic queue length and the time it takes for vehicles to dissipate; Step (34): determining a third phase difference of the traffic light according to the minimum and maximum values ​​of the forward and reverse bidirectional phase differences at the previous road intersection; The output module is configured to: re-time the traffic lights at the current road intersection according to the determined first phase difference of the traffic lights, the second phase difference of the traffic lights, or the third phase difference of the traffic lights, and output the re-timing result.

6. An electronic device, comprising: a memory for non-transitory storage of computer readable instructions; as well as a processor for executing the computer readable instructions, When the computer-readable instructions are executed by the processor, the method described in any one of claims 1 to 4 is executed.

7. A storage medium, characterized in that: The computer-readable instructions are non-transitorily stored, wherein when the computer-readable instructions are executed by a computer, the instructions of the method according to any one of claims 1 to 4 are executed.

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