Intersection stage green light time optimization method, apparatus, device and storage medium

Abstract

The embodiments of the present application provide a method and a device for optimizing green light time of an intersection for a stage, an apparatus equipment and a storage medium. The method includes: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio of each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters. The technical solutions of the present application obtain the stage flow rate ratios based on the critical flow direction of each stage, and then obtain the stage green signal ratios, so that the stage green signal ratio is more accurate and the effect of the optimized signal control timing scheme is improved.

Description

[0001] The present application claims the priority benefit of Chinese Patent application No. 202211676382.0, named "METHOD AND DEVICE FOR OPTIMIZING GREEN LIGHT TIME OF AN INTERSECTION FOR A STAGE, APPARATUS AND STORAGE MEDIUM" and filed with the China National Intellectual Property Administration on December 26, 2022.Technical Filed

[0002] The present application relates to the field of intelligent transportation, and in particular to an optimization a method and a device for optimizing signal control time assignment of an intersection, an apparatus and a storage medium.Background Art

[0003] At present, when optimizing signal control time assignment of an intersection for a stage, flow rate ratios of flow directions are evaluated at least based on data from the detectors at the lane stop lines and the lane departure lines, and then signal control time assignment strategy of the intersection is optimized accordingly.

[0004] However, in the traditional intersections, there are only detectors at the lane stop lines. Even when the flow rate ratios of the flow directions are obtained, optimizing of the signal control time assignment strategy solely based on the flow rate ratios of the flow directions overlooks the impact of saturation flows of some flow directions, thereby resulting in that optimizing of the signal control time assignment strategy fails to meet the time assignment requirements of the flow directions.Summary

[0005] In view of this, embodiments of the present application provide a method and a device for optimizing green light time of an intersection for a stage, an apparatus and a storage medium. The method includes: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio of each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters. The embodiments of the present application obtain the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0006] In a first aspect, the embodiments of the present application provide a method for optimizing green light time of an intersection for a stage, comprising: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio of each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters.

[0007] In this way, the stage flow rate ratio for each of the stages is obtained based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and the stage green signal ratio of each of the stages is obtained based on the stage flow rate ratios for the stages, so that the stage green signal ratio is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0008] In a possible implementation of the first aspect, optimizing green light times of the intersection for the stages based on the stage green signal ratios for stages and signal control configuration parameters comprises: obtaining a time length of a signal control cycle of a signal control time assignment scheme based on the signal control configuration parameters; optimizing the green light times for the stages based on the signal control cycle and the stage green signal ratios for the stages, wherein the green light time for each of the stages is greater than or equal to the maximum value of a stage minimum green light time for that stage and a product of the time length of the signal control cycle and the stage green signal ratio for that stage, and the signal control configuration parameters include the stage minimum green light time. In some embodiments, the signal control configuration parameters further include historical signal control time assignment schemes.

[0009] In this wary, the green light times for the stages obtained based on the green signal ratios meets the traffic demand for the stages, which improves the smoothness of the road.

[0010] In a possible implementation of the first aspect, obtaining a time length of a signal control cycle of the signal control time assignment scheme based on the signal control configuration parameters includes: obtaining a first time length of the signal control cycle based on the signal control configuration parameters, wherein the first time length is a time length that is most frequently used by the signal control cycle in the historical signal control time assignment schemes; obtaining a minimum cycle based on the stage minimum green light time of each of the stages and an all-red time, wherein the time length of the minimum cycle is the sum of the stage minimum green light times for the stages in a signal control cycle and the total all-red time in a signal control cycle; and optimizing the time length of the signal control cycle based on the first time length and the minimum cycle, wherein the time length of the signal control cycle is greater than or equal to the maximum value of the first time length and the time length of the minimum cycle.

[0011] In this way, the time length of the signal control cycle obtained based on the signal control configuration parameters inherits the requirement of the time length of the historical signal control cycle that is most frequently used, while satisfying the requirements of the stage minimum green light time and the all-red time between stages.

[0012] In a possible implementation of the first aspect, the lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time; obtaining the flow direction flow rate ratios and the flow direction adjustment coefficients based on the lane evaluation indicators and the lane configuration data includes: the flow direction flow rate ratio of each of the flow directions is equal to the lane flow rate ratio of a reference lane of that flow direction, and the flow direction adjustment coefficient of each of the flow directions is obtained based on the lane green light utilization rate and the lane idle time of the reference lane of that flow direction, wherein the lane green light utilization rate of the reference lane of each of the flow directions is the largest among lanes having the same flow direction relationship as the reference lane. In some embodiments, the lane idle time of each lane is a time length from the moment at which the lane flow drops to zero for the first time after the green light is on to the end of the green light, the lane green light utilization rate of each lane is used to evaluate a green light time utilization efficiency of that lane based on a lane saturation flow of that lane, and the lane flow rate ratio of each lane is the ratio of a lane departure flow to a lane capacity of that lane.

[0013] In this way, the flow direction flow rate ratio of each flow direction is obtained based on the lane flow rate ratio of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0014] In a possible implementation of the first aspect, the flow direction adjustment coefficient of each of the flow directions varies positively between 1 and a fifth predefined value with the lane green time utilization rate when the lane idle time of the reference lane of that flow direction is greater than or equal to a third predefined value and the lane green time utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value.

[0015] In this way, the flow direction adjustment coefficient of each flow direction is obtained based on the lane green time utilization rate and the lane idle time of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0016] In a possible implementation of the first aspect, if a flow direction includes one-way lanes, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among all lanes of that flow direction.

[0017] In this way, the lane with the highest lane green time utilization rate is preferentially selected as the reference lane, so that the flow direction flow rate ratio obtained based on the reference lane can meet the traffic demand of the lanes of the flow direction.

[0018] In one possible implementation of the first aspect, the lane green time utilization rate of each of the lanes is a ratio of the sum of a lane saturation release time of that lane and a remaining saturation release time of that lane to a maximum lane green time of that lane, wherein the remaining saturation release time of each of the lanes is a time required for a lane flow of that lane after the saturation release time and before the maximum lane green light time to pass at a lane saturation flow of that lane; and the lane saturation release time of each of the lanes is a time length from a moment at which a green light of that lane is on to a moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

[0019] In this way, the lane green time utilization rate obtained based on the lane saturation release time and the maximum lane green time is more accurate.

[0020] In a possible implementation of the first aspect, the lane saturation flow of each of the lanes is a value at a first quantile, sorted from low to high, of non-zero lane flows of that lane within an evaluation period, and each of the lane flows is a flow detected by a lane detector within one detection cycle.

[0021] In this way, compared with the lane design capacity, the lane green time utilization rate calculated by using the lane saturation flow rate obtained based on the actual lane flow is more accurate.

[0022] In a possible implementation of the first aspect, if a lane saturation release time of a lane is greater than or equal to a actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a calculated lane green light time, a detection cycle and a protection interval, and if the lane saturation release time of that lane is less than the actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a minimum lane green light time, the detection cycle and the protection interval; a calculated lane green light time of each lane is a time length from a moment at which a green light of that lane is on to a moment at which a lane flow of that lane drops to zero for the first time within a signal control cycle, and the minimum lane green light time of each lane is a sum of a time required for a total flow of that lane to pass at the lane saturation flow of that lane and a lane lost time. In some embodiments, the protection interval and the detection cycle change positively.

[0023] In this way, the accurate maximum lane green light time is obtained based on the lane saturation release time, the calculated lane green light time and the minimum lane green light time, thereby obtaining a more accurate green light utilization rate.

[0024] In a second aspect, embodiments of the present application provide a device for optimizing green light time of an intersection for a stage, comprising: a flow direction traffic evaluation module configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on detector data and lane configuration data of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction, and the detector data at least includes lane flow of each lane of the intersection in detection cycles; a stage indicator acquisition module configured to obtain stage flow rate ratio of the intersection for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtain stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the stage flow rate ratio for each of the stages is in direct proportion to the product for that stage, and the critical flow direction of each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; a signal control time assignment optimization module configured to optimize green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters.

[0025] In this way, the stage flow rate ratio for each of the stages is obtained based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and the stage green signal ratio of each of the stages is obtained based on the stage flow rate ratios for the stages, so that the stage green signal ratio is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improve.

[0026] In a possible implementation of the second aspect, the signal control time assignment optimization module is further configured to: obtain a time length of a signal control cycle of a signal control time assignment scheme based on the signal control configuration parameters; and optimize the green light times for the stages based on the signal control cycle and the stage green signal ratios for the stages, wherein the green light time for each of the stages is greater than or equal to the maximum value of a stage minimum green light time for that stage and a product of the time length of the signal control cycle and the stage green signal ratio for that stage, and the signal control configuration parameters include the stage minimum green light time. In some embodiments, the signal control configuration parameters further include historical signal control time assignment schemes.

[0027] In this wary, the green light times for the stages obtained based on the green signal ratios meets the traffic demand for the stages, which improves the smoothness of the road.

[0028] In a possible implementation of the second aspect, for obtaining of the time length of the signal control cycle of the signal control time assignment scheme based on the signal control configuration parameters, the signal control time assignment optimization module is specifically configured to: obtain a first time length of the signal control cycle based on the signal control configuration parameters, wherein the first time length is a time length that is most frequently used by the signal control cycle in the historical signal control time assignment schemes; obtain a minimum cycle based on the stage minimum green light time of each of the stages and an all-red time, wherein the time length of the minimum cycle is the sum of the stage minimum green light times for the stages in a signal control cycle and the total all-red time in a signal control cycle; and optimize the time length of the signal control cycle based on the first time length and the minimum cycle, wherein the time length of the signal control cycle is greater than or equal to the maximum value of the first time length and the time length of the minimum cycle.

[0029] In this way, the time length of the signal control cycle obtained based on the signal control configuration parameters inherits the requirement of the time length of the historical signal control cycle that is most frequently used, while satisfying the requirements of the stage minimum green light time and the all-red time between stages.

[0030] In a possible implementation of the second aspect, the lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time; the flow direction flow rate ratio of each of the flow directions is equal to the lane flow rate ratio of a reference lane of that flow direction, and the flow direction adjustment coefficient of each of the flow directions is obtained based on the lane green light utilization rate and the lane idle time of the reference lane of that flow direction, wherein the lane green light utilization rate of the reference lane of each of the flow directions is the largest among lanes having the same flow direction relationship as the reference lane. In some embodiments, the lane idle time of each lane is a time length from the moment at which the lane flow drops to zero for the first time after the green light is on to the end of the green light, the lane green light utilization rate of each lane is used to evaluate a green light time utilization efficiency of that lane based on a lane saturation flow of that lane, and the lane flow rate ratio of each lane is the ratio of a lane departure flow to a lane capacity of that lane.

[0031] In this way, the flow direction flow rate ratio of each flow direction is obtained based on the lane flow rate ratio of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0032] In a possible implementation of the second aspect, the flow direction adjustment coefficient of each of the flow directions varies positively between 1 and a fifth predefined value with the lane green time utilization rate when the lane idle time of the reference lane of that flow direction is greater than or equal to a third predefined value and the lane green time utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value.

[0033] In this way, the flow direction adjustment coefficient of each flow direction is obtained based on the lane green time utilization rate and the lane idle time of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0034] In a possible implementation of the second aspect, if a flow direction includes one-way lanes, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among all lanes of that flow direction.

[0035] In this way, the lane with the highest lane green time utilization rate is preferentially selected as the reference lane, so that the flow direction flow rate ratio obtained based on the reference lane can meet the traffic demand of the lanes of the flow direction.

[0036] In one possible embodiment of the second aspect, the lane green time utilization rate of each of the lanes is a ratio of the sum of a lane saturation release time of that lane and a remaining saturation release time of that lane to a maximum lane green time of that lane, wherein the remaining saturation release time of each of the lanes is a time required for a lane flow of that lane after the saturation release time and before the maximum lane green light time to pass at a lane saturation flow of that lane; and the lane saturation release time of each of the lanes is a time length from a moment at which a green light of that lane is on to a moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

[0037] In this way, the lane green time utilization rate obtained based on the lane saturation release time and the maximum lane green time is more accurate.

[0038] In one possible embodiment of the second aspect, the lane saturation flow of each of the lanes is a value at a first quantile, sorted from low to high, of non-zero lane flows of that lane within an evaluation period, and each of the lane flows is a flow detected by a lane detector within one detection cycle.

[0039] In this way, compared with the lane design capacity, the lane green time utilization rate calculated by using the lane saturation flow rate obtained based on the actual lane flow is more accurate.

[0040] In one possible embodiment of the second aspect, if a lane saturation release time of a lane is greater than or equal to a actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a calculated lane green light time, a detection cycle and a protection interval, and if the lane saturation release time of that lane is less than the actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a minimum lane green light time, the detection cycle and the protection interval; a calculated lane green light time of each lane is a time length from a moment at which a green light of that lane is on to a moment at which a lane flow of that lane drops to zero for the first time within a signal control cycle, and the minimum lane green light time of each lane is a sum of a time required for a total flow of that lane to pass at the lane saturation flow of that lane and a lane lost time. In some embodiments, the protection interval and the detection cycle change positively.

[0041] In this way, the accurate maximum lane green light time is obtained based on the lane saturation release time, the calculated lane green light time and the minimum lane green light time, thereby obtaining a more accurate green light utilization rate.

[0042] In a third aspect, embodiments of the present application provide a computing apparatus, comprising: a bus; a communication interface connected to the bus; at least one processor connected to the bus; and at least one memory connected to the bus and storing program instructions that, when executed by the at least one processor, cause the at least one processor to perform the method according to any of the implementations of the first aspect.

[0043] In a fourth aspect, embodiments of the present application provide a computer-readable storage medium storing thereon program instructions that, when executed by a computer, cause the computer to perform the method according to any of the implementations of the first aspect.Brief Description of the Drawings

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be appreciated that the following drawings only show some embodiments of the present application, and thus should not be regarded as a limitation for the scope of the present application. Other relevant drawings could be obtained based on these drawings without creative efforts for those skilled in the art. Fig. 1 is a schematic flowchart of Embodiment one of a method for optimizing green light time of an intersection for a stage of the present application. Fig. 2 is a schematic flowchart of an embodiment of a method for evaluating flow direction of intersection in Embodiment two of a method for optimizing green light time of an intersection for a stage of the present application. Fig. 3 is a schematic flowchart of an embodiment of a method for evaluating stage green signal ratio of an intersection in Embodiment two of an method for optimizing green light time of an intersection for a stage of the present application. Fig. 4 is a schematic flowchart of an embodiment of a method for optimizing green light time of an intersection for a stage based on stage green signal ratio in Embodiment two of a method for optimizing green light time of an intersection for a stage of the present application. Fig. 5 is a schematic structural diagram of Embodiment one of a device for optimizing green light time of an intersection for a stage of the present application. Fig. 6A is a schematic structural diagram of Embodiment two of a device for optimizing green light time of an intersection for a stage of the present application; Fig. 6B is a schematic structural diagram of a flow direction traffic evaluation module of Embodiment two of a device for optimizing green light time of an intersection for a stage of the present application. Fig. 6C is a schematic structural diagram of a signal control time assignment optimization module of Embodiment two of a device for optimizing green light time of an intersection for a stage of the present application. Fig. 7 is a schematic structural diagram of an embodiment of a computing apparatus of the present application. Detail Description

[0045] In the following description, reference is made to "some embodiments," which describe a subset of all possible embodiments. It should be appreciated that "some embodiments" may refer to the same subset or different subsets of all possible embodiments, and may be combined with each other when there is no conflict.

[0046] In the following description, terms such as "first / second / third" or "module A, module B, module C" are used only to distinguish similar objects or different embodiments, and do not represent a specific order for the objects. It can be appreciated that, where permissible, specific orders or sequences may be interchanged so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0047] In the following description, step labels indicating steps, such as S110, S120, ..., do not necessarily mean that the steps will be executed in this order. Where permissible, the orders of the steps may be interchanged, or the steps may be executed simultaneously.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present application. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0049] Embodiments of the present application provide a method and a device for optimizing green light time of an intersection for a stage, an apparatus, and a storage medium. The method includes: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each flow direction changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages in a signal control time assignment scheme based on the stage green signal ratios for the stages and signal control configuration parameters. The embodiments of the present application obtain the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio for a stage is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0050] The embodiments of the present application will be illustrated below in conjunction with the accompanying drawings.

[0051] First, Embodiment one of a method for optimizing green light time of an intersection for a stage is illustrated in conjunction with Fig. 1.

[0052] Embodiment one of the method for optimizing green light time of an intersection for a stage obtains flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each flow direction changes positively with a saturation level of that flow direction; obtains stage flow rate ratio for each of the stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtains the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage; and optimizes green light times of the intersection for the stages in the signal control time assignment scheme based on the stage green signal ratio for the stages and signal control configuration parameters. The embodiment of the present application obtains the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio for a stage is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0053] Fig. 1 illustrates a flowchart of Embodiment one of the method for optimizing green light time of an intersection for a stage, which includes steps S110 to S140.

[0054] At the step S110, the lane evaluation indicators and the lane configuration data of the lanes of the intersection are acquired.

[0055] The lane configuration data includes lane traffic capacities and flow direction relationships of the lanes. The flow direction relationships are correspondences between related lanes and flow directions, including seven types: straight, left return, right return, straight and right return, straight and left return, straight and left return and right return, and left return and right return. A straight lane, a left-turn lane, and a right-turn lane are one-way lanes, while other lanes are mixed lanes. In some embodiments, the flow direction relationships also include a U turn. Since few vehicles present the U-turn at lanes, the U-turn flow direction is not considered in the embodiments of the present application.

[0056] At the step S120, the flow direction flow rate ratios and the flow direction adjustment coefficients of the flow directions of the intersection are obtained based on the lane evaluation indicators and the lane configuration data.

[0057] The flow direction flow rate ratio of each flow direction is used to evaluate the relationship between a flow and a traffic capacity of that flow direction. The flow direction adjustment coefficients of the flow directions are used to evaluate saturation levels of the flow directions and adjust the flow direction flow rate ratios of the flow directions for a stage when calculating the stage flow rate ratio for the stage. The higher the saturation level of a flow direction is, the larger its flow direction adjustment coefficient will be.

[0058] In some embodiments, the flow rate ratios and lane green light utilization rates of the lanes are acquired; then, a lane with the largest lane green light utilization rate in a flow direction is selected as a reference lane of that flow direction, and a lane flow rate ratio of the reference lane is used as the flow direction flow rate ratio of that flow direction.

[0059] In some embodiments, the flow rate ratios of the lanes are acquired; then, an average value of the flow rate ratios of lanes of a flow direction is selected as the flow direction flow rate ratio of that flow direction.

[0060] At the step S130, the stage green signal ratio of the intersection for each of the stages is obtained based on the flow direction flow rate ratios and the flow direction adjustment coefficients.

[0061] The stage flow rate ratio for each of the stages is obtained based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction of the intersection for that stage, and the stage green signal ratio for each of the stages is obtained based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage.

[0062] In some embodiments, the stage green signal ratio for each of the stages is a ratio of the stage flow rate ratio for that stage and the sum of the stage flow rate ratios for the stages.

[0063] Therefore, when the green light utilization rate is high (i.e., high flow), there is an inaccuracy problem in the statistics of the flow direction flow rate ratios due to saturation. The stage flow rate ratio obtained based on the flow direction flow rate ratios and the flow direction adjustment coefficients can improve the accuracy of the statistics of the stage flow rate ratios.

[0064] At the step S140, a signal control time assignment scheme of the intersection is adjusted based on the stage green signal ratios for the stages, wherein adjusted items of the signal control time assignment scheme include green light times for stages in a signal control cycle.

[0065] In some embodiments, the green light time assigned to each of the stages is obtained by multiplying a preset signal cycle by the stage green signal ratio for that stage.

[0066] In other embodiments, the green light time assigned to each of the stages is obtained by multiplying the stage green signal ratio for that stage by a signal control cycle that is historically most frequently used.

[0067] In summary, Embodiment one of the method for optimizing green light time of an intersection for a stage obtains the flow direction flow rate ratios and the flow direction adjustment coefficients of the flow directions of the intersection based on the lane evaluation indicators and the lane configuration data of the lanes of the intersection, wherein the flow direction adjustment coefficient of each flow direction changes positively with the saturation level of that flow direction; obtains the stage flow rate ratio for each of the stages based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction of the intersection for that stage, and obtains the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage; and optimizes the green light times of the intersection for the stages in the signal control time assignment scheme based on the stage green signal ratio for the stages and the signal control configuration parameters. The embodiment of the present application obtains the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio for a stage is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0068] Embodiment two of the method for optimizing green light time of an intersection for a stage is a detailed implementation of Embodiment one of the method for optimizing green light time of an intersection for a stage, which comprises: an embodiment of a method for evaluating a flow direction of an interaction, an embodiment of a method for evaluating stage green signal ratio, and an embodiment of a method for optimizing the green light time of an intersection for a stage based on stage green signal ratio. These three embodiments are introduced below.

[0069] Fig. 2 illustrates a flowchart of the embodiment of the method for evaluating a flow direction of an intersection, which includes steps S1210 and S1220.

[0070] At the step S1210, lane evaluation indicators of the lanes are obtained based on data from detectors at lane stop lines.

[0071] The lane evaluation indicators are obtained based on the data from the detectors over an evaluation period, wherein the evaluation period comprises multiple signal control cycles. Each signal control cycle has a distinct weighting coefficient in indicator calculation, and a signal control cycle closer to the end of the evaluation period has a higher weighting coefficient. In this embodiment, the lane evaluation indicators are first obtained for each signal control cycle, and then a weighted sum of these indicators is computed using the weighting coefficients of the signal control cycles of the evaluation period.

[0072] The lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time.

[0073] The lane flow rate ratio of each lane is the ratio of a lane departure flow to a lane traffic capacity of that lane, wherein the lane traffic capacity of each lane is obtained from lane configuration data.

[0074] The lane idle time of each lane is a time length from the moment at which the lane flow drops to zero for the first time after the green light is on to the end of the green light.

[0075] The lane green light utilization rate of each lane is used to evaluate a green light time utilization efficiency of that lane based on a lane saturation flow of that lane.

[0076] The lane departure flow of each lane is an average lane flow of that lane within a signal control cycle, with units of vehicles per hour in this embodiment.

[0077] The lane saturation flow of each lane is used to evaluate the sustainable saturation traffic capacity of that lane, the duration of which is beyond at least one detection cycle. In some embodiments, the saturation flow is defined as the maximum value of a value at the first quantile, sorted from low to high, of non-zero lane flows of that lane within the evaluation period and a second predefined value. The highest lane flow represents an instantaneous saturation value that is not sustainable, whereas the value at the first quantile of the lane flows is generally regarded as the saturation traffic capacity that is sustainable. For example, the first quantile is 70%, and when the detection cycle is 6 seconds, the second predefined value is 2.5 vehicles per detection cycle.

[0078] In this way, the lane saturation flow evaluates the sustainable and real lane saturation flow based on actual traffic data.

[0079] In some embodiments, the lane evaluation indicators further include at least one of a lane saturation release time, a calculated lane green light time, a maximum lane green light time, and a minimum lane green light time.

[0080] The lane saturation release time of each lane is a time length from the moment at which the green light of that lane is on to the moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

[0081] The calculated lane green light time of each lane is a time length from the moment at which the green light of that lane is on to the moment at which the lane flow of that lane drops to zero for the first time within a signal control cycle.

[0082] The minimum lane green light time of each lane is a sum of a time required for the total flow of that lane to pass at the lane saturation flow of that lane and a lane lost time.

[0083] If the lane saturation release time of a lane is greater than or equal to the actual green light time of this lane, the maximum lane green light time of this lane is equal to a sum of the calculated lane green light time, the detection cycle, and a predefined protection interval. If the lane saturation release time of a lane is less than the actual green light time of this lane, the maximum lane green light time of this lane is equal to a sum of the minimum lane green light time, the detection cycle, and the predefined protection interval. In some embodiments, the maximum lane green light time is calculated as follows. (1) If the lane saturation release time is greater than or equal to the actual green light time: (2) If the lane saturation release time is less than the actual green light time: Maximum lane green light time = Minimum lane green light time + Detection cycle + Predefined protection interval.

[0084] The lane green light utilization rate for each lane is the ratio of the sum of the lane saturation release time and a remaining saturation release time of that lane to the maximum lane green light time of that lane. The remaining saturation release time is the time required for a lane flow of the corresponding lane between the saturation release time and the maximum green light time to pass at the lane saturation flow. The flow between the lane saturation release time and the maximum lane green light time is derived by proportional conversion from the flow between the lane saturation release time and the calculated lane green light time.

[0085] In some embodiments, the lane green light utilization rate is calculated using Equation (1): Lane green light utilization rate = Lane saturation release time + Remaining lane saturation release time Maximun lane green light time Remaining lane saturation release time = Flow between Calculated lane green light time and Lane saturation release time Lane saturation release time ∗ Remaining conversion factor Remaining conversion factor = Maximun lane green light time − Lane saturation release time Calculated lane green light time − Lane saturation release time

[0086] In this way, by using the above method, the lane green light utilization rate is evaluated more accurately through the minimum lane green light time, the calculated lane green light time, the lane saturation release time and the maximum lane green light time.

[0087] At the step S1220, the flow direction flow rate ratios and the flow direction adjustment coefficients of the flow directions of the intersection are obtained based on the lane evaluation indicators and flow direction relationships of the lanes.

[0088] The flow direction flow rate ratio of each flow direction is equal to the lane flow rate ratio of the reference lane of that flow direction, wherein the reference lane of each flow direction is determined based on the lane green light utilization rates of the lanes corresponding to that flow direction. In some embodiments, if a flow direction includes one-way lanes, the reference lane of that flow direction is the one-way lane with the highest lane green light utilization rate in the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate in all the lanes of that flow direction.

[0089] The flow direction adjustment coefficient of each flow direction varies positively starting from 1 with the lane green time utilization rate when the lane green light utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value, and is set to a fifth predefined value when the lane idle time of the reference lane is less than a third predefined value. For example, the third predefined value is set to 5 seconds, the fourth predefined value to 0.5, and the fifth predefined value to 1.5. In some embodiments, the flow direction adjustment coefficient (denoted as ffq) is calculated as follows. (A) If the lane idle time of the reference lane is less than 5 seconds, ffq is set to the fifth predefined value; otherwise, it proceeds to (B). (B) If the lane green light utilization rate of the reference lane is less than 0.5, ffq is set to 1 and ffq is calculated using Equation (2). ffq = 1 + Lane green light utilization rate − 0.5 0.5 ∗ Fifth predefined value − 1

[0090] For example, the third predefined value is set to 5 seconds and the fourth predefined value is set to 0.5.

[0091] Thus, the embodiment of the method for evaluating a flow direction of an intersection determines the reference lane of a flow direction based on the lane green light utilization rates of the lanes of that flow direction. If the vehicles in the reference lane can pass through completely, vehicles in other lanes of the same flow direction will also pass through completely. By using the lane flow rate ratio of the reference lane as the flow direction flow rate ratio and optimizing the green light time of the flow direction based on this flow direction flow rate ratio, traffic flow efficiency is improved. The flow direction adjustment coefficient obtained from the lane idle time and the lane green light utilization rate of the reference lane is used to adjust the flow direction flow rate ratio when calculating the stage flow rate ratio, which further improves the effect of the optimized signal control time assignment scheme.

[0092] Fig. 3 illustrates a schematic flowchart of the embodiment of the method for evaluating stage green signal ratio of an intersection, which includes steps S1310 to S1330.

[0093] At the step S1310, the critical flow direction for each of the stages is determined based on the flow direction flow rate ratios of the flow directions for that stage.

[0094] The critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage.

[0095] At the step S1320, the stage flow rate ratio for each of the stages is obtained based on the critical flow direction for that stage.

[0096] The stage flow rate ratio for each of the stages is equal to the product of the flow direction flow rate ratio, the flow direction adjustment coefficient, and a flow direction weight coefficient of the critical flow direction for that stage. The flow direction weight coefficient is a manually configured parameter determined based on the ease of traffic in the flow direction. When the ease of traffic in the flow direction is ignored, the stage flow rate ratio for each of the stages is equal to the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction for that stage.

[0097] At the step S1330, the stage green signal ratio for each of the stages is obtained based on the stage flow rate ratios for the stages.

[0098] The stage green signal ratio for each of the stages is equal to a ratio of the stage flow rate ratio for that stage to a total flow rate ratio, wherein the total flow rate ratio is the sum of the stage flow rate ratios of the stages.

[0099] In some embodiments, the stage green signal ratio is calculated using Equation (3). Flow direction i = Flow direction with the largest flow direction flow rate in the caculatin stage Stage flow rate ratio = Flow direction flow rate ratio of i ∗ Flow direction adjustment coefficient of i ∗ Flow direction weight coefficient of i Stage green signal ratio = Stage flow rate ratio ∑ Stage flow rate ratios for the stages

[0100] In this way, the embodiment of the method for evaluating stage green signal ratio of an intersection obtains the stage flow rate ratios from the flow direction flow rate ratios and the flow direction adjustment coefficients, so that the stage green signal ratio calculated based on the stage flow rate ratios is more accurate, which improves the effect of the signal control time assignment scheme optimized based on the stage green signal ratio. Additionally, the stage green signal ratio is calculated by selecting the flow direction with the largest flow rate ratio in a stage, which further improves the effect of the signal control time assignment scheme optimized based on the stage green signal ratio.

[0101] Fig. 4 is a schematic flowchart of the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio, which includes steps S1410 and 1420.

[0102] At the step S1410, an optimized time length of the signal control cycle and a stage minimum green light time for each of the stages are obtained based on the signal control configuration parameters.

[0103] The signal control configuration parameters include at least historical signal time assignment schemes and the stage minimum green light time for each of the stages.

[0104] The step of obtaining the time length of the signal control cycle based on the signal control configuration parameters includes the following steps. (1) A first time length of the signal control cycle is obtained based on the signal control configuration parameters, wherein the first time length is a time length that is most frequently used by the signal control cycle in the historical signal control time assignment schemes. (2) A minimum cycle is obtained based on the stage minimum green light time of each of the stages and an all-red time, wherein the time length of the minimum cycle is the sum of the stage minimum green light times for the stages in a signal control cycle and the total all-red time in a signal control cycle. (3) The time length of the signal control cycle is optimized based on the first time length and the minimum cycle. The time length of the signal control cycle is greater than or equal to the maximum value of the first time length and the time length of the minimum cycle.

[0105] In some embodiments, the signal control configuration parameters further include a maximum cycle. If the time length of the signal control cycle obtained through the above method is greater than the time length of the maximum cycle, the time length of the signal control cycle is adjusted to the time length of the maximum cycle.

[0106] At the step S 1420, green light times for the stages are obtained based on the optimized time length of the signal control cycle, the stage green signal ratios, and the stage minimum green light times.

[0107] The green light time for each of the stages is greater than or equal to the maximum value of the stage minimum green light time for that stage and the product of the optimized time length of the signal control cycle and the stage green signal ratio for that stage.

[0108] In some embodiments, this step includes the following sub-steps. (A) the green light time is assigned for each of the stages in the signal control cycle based on the stage green signal ratios and the optimized time length of the signal control cycle and that stage is marked.

[0109] If a stage is an invalid stage, the green light time for that stage = the stage minimum green light time, and that stage is marked.

[0110] If a stage is not an invalid stage, the green light time for that stage = the optimized time length of the signal control cycle * the stage green signal ratio for that stage. If the green light time for a stage is less than the stage minimum green light time, the green light time for that stage is adjusted to the stage minimum green light time and that stage is marked.

[0111] (B) The number N of marked stages is acquired; when N = 0, assignment of the green light time is complete; otherwise, sub-steps (C), (D), and (E) are executed in sequence, and then the sub-step (B) is executed in a loop.

[0112] (C) A quotient obtained by dividing the stage green signal ratio for each of unmarked stages by the sum of the stage green signal ratios for all the unmarked stages is taken as a new stage green signal ratio for that unmarked stage, and a difference obtained by subtracting N times of the stage minimum green light time from the optimized time length of the signal control cycle is taken as a new time length of the signal control cycle.

[0113] (D) The product of the new stage green signal ratio for each of the unmarked stages and the new time length of the signal control cycle is taken as the green light time for that unmarked stage.

[0114] (E) N is set to zero, and the unmarked stages are traversed, wherein when the new green light time for a stage is less than the stage minimum green light time, the green light time for that stage is adjusted to the stage minimum green light time, that stage is marked, and the number N of marked stages is accumulated.

[0115] Thus, the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio obtains the time length of the signal control cycle based on the signal control configuration parameters, and assigns green light times of the intersection for the stages based on the stage green signal ratios, wherein the assigned green light time is greater than or equal to the configured stage minimum green light time. This improves the effect of the optimized signal time assignment scheme.

[0116] In summary, Embodiment two of the method for optimizing green light time of an intersection for a stage evaluates the lane green light utilization rate more accurately through the minimum lane green light time, the calculated lane green light time, the lane saturation release time, and the maximum lane green light time, thereby determining the accurate reference lanes of the flow directions and obtaining the accurate flow direction flow rate ratios and flow direction adjustment coefficients. Meanwhile, the stage green signal ratios are calculated by selecting the flow directions with the largest flow direction flow rate ratio, which further improves the effect of the signal time assignment scheme optimized based on the stage green signal ratios.

[0117] Device embodiments of the present application are illustrated in conjunction with Figs. 5 to 6C.

[0118] Fig. 5 shows a structure of Embodiment one of a device for optimizing green light time of an intersection for a stage, which includes: a data acquisition module 510, a flow direction traffic evaluation module 520, a stage indicator acquisition module 530, and a signal control time assignment optimization module 540.

[0119] The data acquisition module 510 is configured to acquire lane evaluation indicators and lane configuration data of lanes of an intersection. Principles and advantages of this module may be referred to the step S110 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0120] The flow direction traffic evaluation module 520 is configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of the intersection based on the lane evaluation indicators and the lane configuration data. Principles and advantages of this module may be referred to the step S120 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0121] The stage indicator acquisition module 530 is configured to obtain stage green signal ratio of the intersection for each of stages based on the flow direction flow rate ratios for the stages and the flow direction adjustment coefficients. Principles and advantages of this module may be referred to the step S130 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0122] The signal control time assignment optimization module 540 is configured to adjust a signal control time assignment scheme of the intersection based on the stage green signal ratios for the stages, wherein adjusted items of the signal control time assignment scheme include green light times for stages in a signal control cycle. Principles and advantages of this module may be referred to the step S140 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0123] Figure 6A shows a structure of Embodiment two of the device for optimizing green light time of an intersection for a stage, which includes a data acquisition module 610, a flow direction traffic evaluation module 620, a stage indicator acquisition module 630, and a signal control time assignment optimization module 640.

[0124] The data acquisition module 610 is configured to acquire data from detectors at lane stop lines and lane configuration data for lanes of an intersection.

[0125] The flow direction traffic evaluation module 620 is configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of the intersection based on the data from the detectors at the lane stop line and the lane configuration data for the lanes. Principles and advantages of this module may be referred to the embodiment of the method for evaluating a flow direction of an interaction.

[0126] The stage indicator acquisition module 630 is configured to obtain stage green signal ratio of the intersection for each of stages based on the flow direction flow rate ratios for the stages and flow direction adjustment coefficients. Principles and advantages of this module may be referred to the embodiment of the method for evaluating stage green signal ratio of an intersection.

[0127] The signal control time assignment optimization module 640 is configured to adjust a signal control time assignment scheme of the intersection based on the stage green signal ratios for the stages, wherein adjusted items of the signal control time assignment scheme include green light times for stages in a signal control cycle. Principles and advantages of this module may be referred to the embodiment of the method for optimizing green light time of an intersection for a stage.

[0128] Figure 6B shows a structure of the flow direction traffic evaluation module 620, which includes: a lane indicator acquisition module 6210 and a flow direction indicator acquisition module 6220.

[0129] The lane indicator acquisition module 6210 is configured to obtain lane evaluation indicators of the lanes based on the data from the detectors at the lane stop line. Principles and advantages of this module may be referred to the step S1210 of the embodiment of the method for evaluating a flow direction of an intersection.

[0130] The flow direction indicator acquisition module 6220 is configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients for the flow directions of the intersection based on the lane evaluation indicators and flow direction relationships of the lanes. Principles and advantages of this module may be referred to the step S1220 of the embodiment of the method for evaluating a flow direction of an intersection.

[0131] Figure 6C shows a structure of the signal control time assignment optimization module 640, which includes: a signal control cycle acquisition module 6410 and a green light time optimization module 6420.

[0132] The signal control cycle acquisition module 6410 is configured to obtain an optimized time length of the signal control cycle and a stage minimum green light time for each of the stages based on signal control configuration parameters. Principles and advantages of this module may be referred to the step S1410 of the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio.

[0133] The green light time optimization module 6420 is configured to obtain green light times of the stages based on the time length of the signal control cycle, the stage green signal ratios, and the stage minimum green light times. Principles and advantages of this module may be referred to the step S1420 of the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio.

[0134] Another embodiment of the present application provides a traffic control system, which comprises traffic lights disposed at an intersection, a controller, and the device for optimizing green light time of an intersection for a stage provided in the above embodiments. The traffic lights and the controller are communicatively connected to the device for optimizing green light time of an intersection for a stage via communication. The controller is configured to receive the green light time of the intersection for each of the stages transmitted by the device for optimizing green light time of an intersection for a stage, and control, according to the received green light time of the intersection for each of the stages, the traffic lights to display at corresponding light colors and durations, thereby instructing travelling of traffic objects.

[0135] An embodiment of the present application further provides a computing apparatus, which is described in detail below with reference to Fig. 7.

[0136] The computing apparatus 700 includes a processor 710, a memory 720, a communication interface 730, and a bus 740.

[0137] It should be appreciated that the communication interface 730 in the computing apparatus 700 shown in this figure may be used for communication with other devices.

[0138] The processor 710 may be connected to the memory 720. The memory 720 may be used to store program codes and data. Therefore, the memory 720 may be a storage unit inside the processor 710, an external storage unit independent of the processor 710, or a component including both the storage unit inside the processor 710 and the external storage unit independent of the processor 710.

[0139] Optionally, the computing apparatus 700 may further include the bus 740. The memory 720 and the communication interface 730 may be connected to the processor 710 via the bus 740. The bus 740 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, and the like. The bus 740 may be classified as address bus, data bus, control bus, and the like. For ease of representation, only one line is shown in the figure, but this does not indicate only one bus or one type of bus.

[0140] It should be appreciated that in the embodiments of the present application, the processor 710 may employ a central processing unit (CPU). The processor may also be other general-purpose processor, a digital signal processors (DSP), an application-specific integrated circuits (ASIC), a field programmable gate arrays (FPGA) or other programmable logic devices discrete gate or transistor logic devices discrete hardware component, and the like. The general-purpose processor may be a microprocessor, any conventional processor, or the like. Alternatively, the processor 710 employs one or more integrated circuits for executing relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0141] The memory 720 may include a read-only memory and a random access memory, and provide instructions and data to the processor 710. A part of the processor 710 may also include a non-volatile random access memory. For example, the processor 710 may also store information about the type of the storage device.

[0142] When the computing apparatus 700 is running, the processor 710 executes the computer execution instructions in the memory 720 to perform the operational steps of the embodiments of the method.

[0143] It should be appreciated that the computing apparatus 700 according to the embodiments of the present application may correspond to the subject performing the methods according to the various embodiments of the present application, and the above-described and other operations and / or functions of each module in the computing apparatus 700 are respectively for implementing the corresponding processes of the methods in this embodiment. For the sake of simplicity, it will not be elaborated herein.

[0144] Those skilled in the art can appreciate that the units and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals may use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the present application.

[0145] Those skilled in the art will clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above may refer to the corresponding procedures in the foregoing method embodiments, and will not be elaborated here.

[0146] In the several embodiments provided in the present application, it should be appreciated that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not executed. Additionally, the shown or discussed mutual coupling, direct coupling, or communication connections may be indirect coupling or communication connections via some interfaces, devices, or units, which may be in electrical, mechanical, or other forms.

[0147] The units described as separate components may or may not be physically separated. Components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Part or all of the units may be selected according to actual needs to achieve the objectives of the embodiments herein.

[0148] Furthermore, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically independently, or two or more units may be integrated into one unit.

[0149] If the functions are implemented in the form of software functional units and sold or used as independent products, they may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application-in essence, or the part that makes a contribution over the prior art-may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (such as a personal computer, server, or network device) to perform all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage media include: a USB flash drive, a portable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disc, and other media capable of storing program code.

[0150] An embodiment of the present application provides a computer-readable storage medium storing thereon a computer program that, when executed by a processor, performs the operational steps of the method embodiments.

[0151] The computer storage medium of the present application embodiments may employ any combination of one or more computer-readable media. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include an electrical connection with one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In this document, a computer-readable storage medium may be any tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device.

[0152] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, in which computer-readable program code is embodied. Such a propagated data signal may be in various forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0153] Program code contained on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, and the like, or any suitable combination of the foregoing.

[0154] Computer program code for performing the operations of the present application may be written in one or more programming languages or combinations thereof, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional procedural programming languages such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0155] It should be appreciated that the above are only preferred embodiments of the present application and the technical principles employed. Those skilled in the art should be appreciated that the present application is not limited to the specific embodiments described herein, and that various obvious modifications, rearrangements, and substitutions may be made by those skilled in the art without deviating from the scope of protection of the present application. Therefore, although the present application has been described in relatively detailed terms through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, it may further include more other equivalent embodiments, all of which fall within the protection scope of the present application.

Examples

Embodiment Construction

[0045]In the following description, reference is made to "some embodiments," which describe a subset of all possible embodiments. It should be appreciated that "some embodiments" may refer to the same subset or different subsets of all possible embodiments, and may be combined with each other when there is no conflict.

[0046]In the following description, terms such as "first / second / third" or "module A, module B, module C" are used only to distinguish similar objects or different embodiments, and do not represent a specific order for the objects. It can be appreciated that, where permissible, specific orders or sequences may be interchanged so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0047]In the following description, step labels indicating steps, such as S110, S120, ..., do not necessarily mean that the steps will be executed in this order. Where permissible, the orders of the step...

[0001] The present application claims the priority benefit of Chinese Patent application No. 202211676382.0, named "METHOD AND DEVICE FOR OPTIMIZING GREEN LIGHT TIME OF AN INTERSECTION FOR A STAGE, APPARATUS AND STORAGE MEDIUM" and filed with the China National Intellectual Property Administration on December 26, 2022.Technical Filed

[0002] The present application relates to the field of intelligent transportation, and in particular to an optimization a method and a device for optimizing signal control time assignment of an intersection, an apparatus and a storage medium.Background Art

[0003] At present, when optimizing signal control time assignment of an intersection for a stage, flow rate ratios of flow directions are evaluated at least based on data from the detectors at the lane stop lines and the lane departure lines, and then signal control time assignment strategy of the intersection is optimized accordingly.

[0004] However, in the traditional intersections, there are only detectors at the lane stop lines. Even when the flow rate ratios of the flow directions are obtained, optimizing of the signal control time assignment strategy solely based on the flow rate ratios of the flow directions overlooks the impact of saturation flows of some flow directions, thereby resulting in that optimizing of the signal control time assignment strategy fails to meet the time assignment requirements of the flow directions.Summary

[0005] In view of this, embodiments of the present application provide a method and a device for optimizing green light time of an intersection for a stage, an apparatus and a storage medium. The method includes: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio of each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters. The embodiments of the present application obtain the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0006] In a first aspect, the embodiments of the present application provide a method for optimizing green light time of an intersection for a stage, comprising: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio of each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters.

[0007] In this way, the stage flow rate ratio for each of the stages is obtained based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and the stage green signal ratio of each of the stages is obtained based on the stage flow rate ratios for the stages, so that the stage green signal ratio is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0008] In a possible implementation of the first aspect, optimizing green light times of the intersection for the stages based on the stage green signal ratios for stages and signal control configuration parameters comprises: obtaining a time length of a signal control cycle of a signal control time assignment scheme based on the signal control configuration parameters; optimizing the green light times for the stages based on the signal control cycle and the stage green signal ratios for the stages, wherein the green light time for each of the stages is greater than or equal to the maximum value of a stage minimum green light time for that stage and a product of the time length of the signal control cycle and the stage green signal ratio for that stage, and the signal control configuration parameters include the stage minimum green light time. In some embodiments, the signal control configuration parameters further include historical signal control time assignment schemes.

[0009] In this wary, the green light times for the stages obtained based on the green signal ratios meets the traffic demand for the stages, which improves the smoothness of the road.

[0010] In a possible implementation of the first aspect, obtaining a time length of a signal control cycle of the signal control time assignment scheme based on the signal control configuration parameters includes: obtaining a first time length of the signal control cycle based on the signal control configuration parameters, wherein the first time length is a time length that is most frequently used by the signal control cycle in the historical signal control time assignment schemes; obtaining a minimum cycle based on the stage minimum green light time of each of the stages and an all-red time, wherein the time length of the minimum cycle is the sum of the stage minimum green light times for the stages in a signal control cycle and the total all-red time in a signal control cycle; and optimizing the time length of the signal control cycle based on the first time length and the minimum cycle, wherein the time length of the signal control cycle is greater than or equal to the maximum value of the first time length and the time length of the minimum cycle.

[0011] In this way, the time length of the signal control cycle obtained based on the signal control configuration parameters inherits the requirement of the time length of the historical signal control cycle that is most frequently used, while satisfying the requirements of the stage minimum green light time and the all-red time between stages.

[0012] In a possible implementation of the first aspect, the lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time; obtaining the flow direction flow rate ratios and the flow direction adjustment coefficients based on the lane evaluation indicators and the lane configuration data includes: the flow direction flow rate ratio of each of the flow directions is equal to the lane flow rate ratio of a reference lane of that flow direction, and the flow direction adjustment coefficient of each of the flow directions is obtained based on the lane green light utilization rate and the lane idle time of the reference lane of that flow direction, wherein the lane green light utilization rate of the reference lane of each of the flow directions is the largest among lanes having the same flow direction relationship as the reference lane. In some embodiments, the lane idle time of each lane is a time length from the moment at which the lane flow drops to zero for the first time after the green light is on to the end of the green light, the lane green light utilization rate of each lane is used to evaluate a green light time utilization efficiency of that lane based on a lane saturation flow of that lane, and the lane flow rate ratio of each lane is the ratio of a lane departure flow to a lane capacity of that lane.

[0013] In this way, the flow direction flow rate ratio of each flow direction is obtained based on the lane flow rate ratio of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0014] In a possible implementation of the first aspect, the flow direction adjustment coefficient of each of the flow directions varies positively between 1 and a fifth predefined value with the lane green time utilization rate when the lane idle time of the reference lane of that flow direction is greater than or equal to a third predefined value and the lane green time utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value.

[0015] In this way, the flow direction adjustment coefficient of each flow direction is obtained based on the lane green time utilization rate and the lane idle time of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0016] In a possible implementation of the first aspect, if a flow direction includes one-way lanes, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among all lanes of that flow direction.

[0017] In this way, the lane with the highest lane green time utilization rate is preferentially selected as the reference lane, so that the flow direction flow rate ratio obtained based on the reference lane can meet the traffic demand of the lanes of the flow direction.

[0018] In one possible implementation of the first aspect, the lane green time utilization rate of each of the lanes is a ratio of the sum of a lane saturation release time of that lane and a remaining saturation release time of that lane to a maximum lane green time of that lane, wherein the remaining saturation release time of each of the lanes is a time required for a lane flow of that lane after the saturation release time and before the maximum lane green light time to pass at a lane saturation flow of that lane; and the lane saturation release time of each of the lanes is a time length from a moment at which a green light of that lane is on to a moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

[0019] In this way, the lane green time utilization rate obtained based on the lane saturation release time and the maximum lane green time is more accurate.

[0020] In a possible implementation of the first aspect, the lane saturation flow of each of the lanes is a value at a first quantile, sorted from low to high, of non-zero lane flows of that lane within an evaluation period, and each of the lane flows is a flow detected by a lane detector within one detection cycle.

[0021] In this way, compared with the lane design capacity, the lane green time utilization rate calculated by using the lane saturation flow rate obtained based on the actual lane flow is more accurate.

[0022] In a possible implementation of the first aspect, if a lane saturation release time of a lane is greater than or equal to a actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a calculated lane green light time, a detection cycle and a protection interval, and if the lane saturation release time of that lane is less than the actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a minimum lane green light time, the detection cycle and the protection interval; a calculated lane green light time of each lane is a time length from a moment at which a green light of that lane is on to a moment at which a lane flow of that lane drops to zero for the first time within a signal control cycle, and the minimum lane green light time of each lane is a sum of a time required for a total flow of that lane to pass at the lane saturation flow of that lane and a lane lost time. In some embodiments, the protection interval and the detection cycle change positively.

[0023] In this way, the accurate maximum lane green light time is obtained based on the lane saturation release time, the calculated lane green light time and the minimum lane green light time, thereby obtaining a more accurate green light utilization rate.

[0024] In a second aspect, embodiments of the present application provide a device for optimizing green light time of an intersection for a stage, comprising: a flow direction traffic evaluation module configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on detector data and lane configuration data of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction, and the detector data at least includes lane flow of each lane of the intersection in detection cycles; a stage indicator acquisition module configured to obtain stage flow rate ratio of the intersection for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtain stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the stage flow rate ratio for each of the stages is in direct proportion to the product for that stage, and the critical flow direction of each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; a signal control time assignment optimization module configured to optimize green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters.

[0025] In this way, the stage flow rate ratio for each of the stages is obtained based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and the stage green signal ratio of each of the stages is obtained based on the stage flow rate ratios for the stages, so that the stage green signal ratio is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improve.

[0026] In a possible implementation of the second aspect, the signal control time assignment optimization module is further configured to: obtain a time length of a signal control cycle of a signal control time assignment scheme based on the signal control configuration parameters; and optimize the green light times for the stages based on the signal control cycle and the stage green signal ratios for the stages, wherein the green light time for each of the stages is greater than or equal to the maximum value of a stage minimum green light time for that stage and a product of the time length of the signal control cycle and the stage green signal ratio for that stage, and the signal control configuration parameters include the stage minimum green light time. In some embodiments, the signal control configuration parameters further include historical signal control time assignment schemes.

[0027] In this wary, the green light times for the stages obtained based on the green signal ratios meets the traffic demand for the stages, which improves the smoothness of the road.

[0028] In a possible implementation of the second aspect, for obtaining of the time length of the signal control cycle of the signal control time assignment scheme based on the signal control configuration parameters, the signal control time assignment optimization module is specifically configured to: obtain a first time length of the signal control cycle based on the signal control configuration parameters, wherein the first time length is a time length that is most frequently used by the signal control cycle in the historical signal control time assignment schemes; obtain a minimum cycle based on the stage minimum green light time of each of the stages and an all-red time, wherein the time length of the minimum cycle is the sum of the stage minimum green light times for the stages in a signal control cycle and the total all-red time in a signal control cycle; and optimize the time length of the signal control cycle based on the first time length and the minimum cycle, wherein the time length of the signal control cycle is greater than or equal to the maximum value of the first time length and the time length of the minimum cycle.

[0029] In this way, the time length of the signal control cycle obtained based on the signal control configuration parameters inherits the requirement of the time length of the historical signal control cycle that is most frequently used, while satisfying the requirements of the stage minimum green light time and the all-red time between stages.

[0030] In a possible implementation of the second aspect, the lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time; the flow direction flow rate ratio of each of the flow directions is equal to the lane flow rate ratio of a reference lane of that flow direction, and the flow direction adjustment coefficient of each of the flow directions is obtained based on the lane green light utilization rate and the lane idle time of the reference lane of that flow direction, wherein the lane green light utilization rate of the reference lane of each of the flow directions is the largest among lanes having the same flow direction relationship as the reference lane. In some embodiments, the lane idle time of each lane is a time length from the moment at which the lane flow drops to zero for the first time after the green light is on to the end of the green light, the lane green light utilization rate of each lane is used to evaluate a green light time utilization efficiency of that lane based on a lane saturation flow of that lane, and the lane flow rate ratio of each lane is the ratio of a lane departure flow to a lane capacity of that lane.

[0031] In this way, the flow direction flow rate ratio of each flow direction is obtained based on the lane flow rate ratio of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0032] In a possible implementation of the second aspect, the flow direction adjustment coefficient of each of the flow directions varies positively between 1 and a fifth predefined value with the lane green time utilization rate when the lane idle time of the reference lane of that flow direction is greater than or equal to a third predefined value and the lane green time utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value.

[0033] In this way, the flow direction adjustment coefficient of each flow direction is obtained based on the lane green time utilization rate and the lane idle time of the reference lane of that flow direction, thereby obtaining a more accurate stage green signal ratio.

[0034] In a possible implementation of the second aspect, if a flow direction includes one-way lanes, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among all lanes of that flow direction.

[0035] In this way, the lane with the highest lane green time utilization rate is preferentially selected as the reference lane, so that the flow direction flow rate ratio obtained based on the reference lane can meet the traffic demand of the lanes of the flow direction.

[0036] In one possible embodiment of the second aspect, the lane green time utilization rate of each of the lanes is a ratio of the sum of a lane saturation release time of that lane and a remaining saturation release time of that lane to a maximum lane green time of that lane, wherein the remaining saturation release time of each of the lanes is a time required for a lane flow of that lane after the saturation release time and before the maximum lane green light time to pass at a lane saturation flow of that lane; and the lane saturation release time of each of the lanes is a time length from a moment at which a green light of that lane is on to a moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

[0037] In this way, the lane green time utilization rate obtained based on the lane saturation release time and the maximum lane green time is more accurate.

[0038] In one possible embodiment of the second aspect, the lane saturation flow of each of the lanes is a value at a first quantile, sorted from low to high, of non-zero lane flows of that lane within an evaluation period, and each of the lane flows is a flow detected by a lane detector within one detection cycle.

[0039] In this way, compared with the lane design capacity, the lane green time utilization rate calculated by using the lane saturation flow rate obtained based on the actual lane flow is more accurate.

[0040] In one possible embodiment of the second aspect, if a lane saturation release time of a lane is greater than or equal to a actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a calculated lane green light time, a detection cycle and a protection interval, and if the lane saturation release time of that lane is less than the actual green light time of that lane, the maximum lane green light time of that lane is equal to a sum of a minimum lane green light time, the detection cycle and the protection interval; a calculated lane green light time of each lane is a time length from a moment at which a green light of that lane is on to a moment at which a lane flow of that lane drops to zero for the first time within a signal control cycle, and the minimum lane green light time of each lane is a sum of a time required for a total flow of that lane to pass at the lane saturation flow of that lane and a lane lost time. In some embodiments, the protection interval and the detection cycle change positively.

[0041] In this way, the accurate maximum lane green light time is obtained based on the lane saturation release time, the calculated lane green light time and the minimum lane green light time, thereby obtaining a more accurate green light utilization rate.

[0042] In a third aspect, embodiments of the present application provide a computing apparatus, comprising: a bus; a communication interface connected to the bus; at least one processor connected to the bus; and at least one memory connected to the bus and storing program instructions that, when executed by the at least one processor, cause the at least one processor to perform the method according to any of the implementations of the first aspect.

[0043] In a fourth aspect, embodiments of the present application provide a computer-readable storage medium storing thereon program instructions that, when executed by a computer, cause the computer to perform the method according to any of the implementations of the first aspect.Brief Description of the Drawings

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be appreciated that the following drawings only show some embodiments of the present application, and thus should not be regarded as a limitation for the scope of the present application. Other relevant drawings could be obtained based on these drawings without creative efforts for those skilled in the art. Fig. 1 is a schematic flowchart of Embodiment one of a method for optimizing green light time of an intersection for a stage of the present application. Fig. 2 is a schematic flowchart of an embodiment of a method for evaluating flow direction of intersection in Embodiment two of a method for optimizing green light time of an intersection for a stage of the present application. Fig. 3 is a schematic flowchart of an embodiment of a method for evaluating stage green signal ratio of an intersection in Embodiment two of an method for optimizing green light time of an intersection for a stage of the present application. Fig. 4 is a schematic flowchart of an embodiment of a method for optimizing green light time of an intersection for a stage based on stage green signal ratio in Embodiment two of a method for optimizing green light time of an intersection for a stage of the present application. Fig. 5 is a schematic structural diagram of Embodiment one of a device for optimizing green light time of an intersection for a stage of the present application. Fig. 6A is a schematic structural diagram of Embodiment two of a device for optimizing green light time of an intersection for a stage of the present application; Fig. 6B is a schematic structural diagram of a flow direction traffic evaluation module of Embodiment two of a device for optimizing green light time of an intersection for a stage of the present application. Fig. 6C is a schematic structural diagram of a signal control time assignment optimization module of Embodiment two of a device for optimizing green light time of an intersection for a stage of the present application. Fig. 7 is a schematic structural diagram of an embodiment of a computing apparatus of the present application. Detail Description

[0045] In the following description, reference is made to "some embodiments," which describe a subset of all possible embodiments. It should be appreciated that "some embodiments" may refer to the same subset or different subsets of all possible embodiments, and may be combined with each other when there is no conflict.

[0046] In the following description, terms such as "first / second / third" or "module A, module B, module C" are used only to distinguish similar objects or different embodiments, and do not represent a specific order for the objects. It can be appreciated that, where permissible, specific orders or sequences may be interchanged so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0047] In the following description, step labels indicating steps, such as S110, S120, ..., do not necessarily mean that the steps will be executed in this order. Where permissible, the orders of the steps may be interchanged, or the steps may be executed simultaneously.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present application. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0049] Embodiments of the present application provide a method and a device for optimizing green light time of an intersection for a stage, an apparatus, and a storage medium. The method includes: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each flow direction changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages in a signal control time assignment scheme based on the stage green signal ratios for the stages and signal control configuration parameters. The embodiments of the present application obtain the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio for a stage is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0050] The embodiments of the present application will be illustrated below in conjunction with the accompanying drawings.

[0051] First, Embodiment one of a method for optimizing green light time of an intersection for a stage is illustrated in conjunction with Fig. 1.

[0052] Embodiment one of the method for optimizing green light time of an intersection for a stage obtains flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each flow direction changes positively with a saturation level of that flow direction; obtains stage flow rate ratio for each of the stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtains the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage; and optimizes green light times of the intersection for the stages in the signal control time assignment scheme based on the stage green signal ratio for the stages and signal control configuration parameters. The embodiment of the present application obtains the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio for a stage is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0053] Fig. 1 illustrates a flowchart of Embodiment one of the method for optimizing green light time of an intersection for a stage, which includes steps S110 to S140.

[0054] At the step S110, the lane evaluation indicators and the lane configuration data of the lanes of the intersection are acquired.

[0055] The lane configuration data includes lane traffic capacities and flow direction relationships of the lanes. The flow direction relationships are correspondences between related lanes and flow directions, including seven types: straight, left return, right return, straight and right return, straight and left return, straight and left return and right return, and left return and right return. A straight lane, a left-turn lane, and a right-turn lane are one-way lanes, while other lanes are mixed lanes. In some embodiments, the flow direction relationships also include a U turn. Since few vehicles present the U-turn at lanes, the U-turn flow direction is not considered in the embodiments of the present application.

[0056] At the step S120, the flow direction flow rate ratios and the flow direction adjustment coefficients of the flow directions of the intersection are obtained based on the lane evaluation indicators and the lane configuration data.

[0057] The flow direction flow rate ratio of each flow direction is used to evaluate the relationship between a flow and a traffic capacity of that flow direction. The flow direction adjustment coefficients of the flow directions are used to evaluate saturation levels of the flow directions and adjust the flow direction flow rate ratios of the flow directions for a stage when calculating the stage flow rate ratio for the stage. The higher the saturation level of a flow direction is, the larger its flow direction adjustment coefficient will be.

[0058] In some embodiments, the flow rate ratios and lane green light utilization rates of the lanes are acquired; then, a lane with the largest lane green light utilization rate in a flow direction is selected as a reference lane of that flow direction, and a lane flow rate ratio of the reference lane is used as the flow direction flow rate ratio of that flow direction.

[0059] In some embodiments, the flow rate ratios of the lanes are acquired; then, an average value of the flow rate ratios of lanes of a flow direction is selected as the flow direction flow rate ratio of that flow direction.

[0060] At the step S130, the stage green signal ratio of the intersection for each of the stages is obtained based on the flow direction flow rate ratios and the flow direction adjustment coefficients.

[0061] The stage flow rate ratio for each of the stages is obtained based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction of the intersection for that stage, and the stage green signal ratio for each of the stages is obtained based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage.

[0062] In some embodiments, the stage green signal ratio for each of the stages is a ratio of the stage flow rate ratio for that stage and the sum of the stage flow rate ratios for the stages.

[0063] Therefore, when the green light utilization rate is high (i.e., high flow), there is an inaccuracy problem in the statistics of the flow direction flow rate ratios due to saturation. The stage flow rate ratio obtained based on the flow direction flow rate ratios and the flow direction adjustment coefficients can improve the accuracy of the statistics of the stage flow rate ratios.

[0064] At the step S140, a signal control time assignment scheme of the intersection is adjusted based on the stage green signal ratios for the stages, wherein adjusted items of the signal control time assignment scheme include green light times for stages in a signal control cycle.

[0065] In some embodiments, the green light time assigned to each of the stages is obtained by multiplying a preset signal cycle by the stage green signal ratio for that stage.

[0066] In other embodiments, the green light time assigned to each of the stages is obtained by multiplying the stage green signal ratio for that stage by a signal control cycle that is historically most frequently used.

[0067] In summary, Embodiment one of the method for optimizing green light time of an intersection for a stage obtains the flow direction flow rate ratios and the flow direction adjustment coefficients of the flow directions of the intersection based on the lane evaluation indicators and the lane configuration data of the lanes of the intersection, wherein the flow direction adjustment coefficient of each flow direction changes positively with the saturation level of that flow direction; obtains the stage flow rate ratio for each of the stages based on the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction of the intersection for that stage, and obtains the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage; and optimizes the green light times of the intersection for the stages in the signal control time assignment scheme based on the stage green signal ratio for the stages and the signal control configuration parameters. The embodiment of the present application obtains the stage flow rate ratio for each of the stages based on the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction for that stage, and then obtain the stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, so that the stage green signal ratio for a stage is more accurate when there are saturation lanes in the stage, and the effect of the optimized signal control time assignment scheme is improved.

[0068] Embodiment two of the method for optimizing green light time of an intersection for a stage is a detailed implementation of Embodiment one of the method for optimizing green light time of an intersection for a stage, which comprises: an embodiment of a method for evaluating a flow direction of an interaction, an embodiment of a method for evaluating stage green signal ratio, and an embodiment of a method for optimizing the green light time of an intersection for a stage based on stage green signal ratio. These three embodiments are introduced below.

[0069] Fig. 2 illustrates a flowchart of the embodiment of the method for evaluating a flow direction of an intersection, which includes steps S1210 and S1220.

[0070] At the step S1210, lane evaluation indicators of the lanes are obtained based on data from detectors at lane stop lines.

[0071] The lane evaluation indicators are obtained based on the data from the detectors over an evaluation period, wherein the evaluation period comprises multiple signal control cycles. Each signal control cycle has a distinct weighting coefficient in indicator calculation, and a signal control cycle closer to the end of the evaluation period has a higher weighting coefficient. In this embodiment, the lane evaluation indicators are first obtained for each signal control cycle, and then a weighted sum of these indicators is computed using the weighting coefficients of the signal control cycles of the evaluation period.

[0072] The lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time.

[0073] The lane flow rate ratio of each lane is the ratio of a lane departure flow to a lane traffic capacity of that lane, wherein the lane traffic capacity of each lane is obtained from lane configuration data.

[0074] The lane idle time of each lane is a time length from the moment at which the lane flow drops to zero for the first time after the green light is on to the end of the green light.

[0075] The lane green light utilization rate of each lane is used to evaluate a green light time utilization efficiency of that lane based on a lane saturation flow of that lane.

[0076] The lane departure flow of each lane is an average lane flow of that lane within a signal control cycle, with units of vehicles per hour in this embodiment.

[0077] The lane saturation flow of each lane is used to evaluate the sustainable saturation traffic capacity of that lane, the duration of which is beyond at least one detection cycle. In some embodiments, the saturation flow is defined as the maximum value of a value at the first quantile, sorted from low to high, of non-zero lane flows of that lane within the evaluation period and a second predefined value. The highest lane flow represents an instantaneous saturation value that is not sustainable, whereas the value at the first quantile of the lane flows is generally regarded as the saturation traffic capacity that is sustainable. For example, the first quantile is 70%, and when the detection cycle is 6 seconds, the second predefined value is 2.5 vehicles per detection cycle.

[0078] In this way, the lane saturation flow evaluates the sustainable and real lane saturation flow based on actual traffic data.

[0079] In some embodiments, the lane evaluation indicators further include at least one of a lane saturation release time, a calculated lane green light time, a maximum lane green light time, and a minimum lane green light time.

[0080] The lane saturation release time of each lane is a time length from the moment at which the green light of that lane is on to the moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

[0081] The calculated lane green light time of each lane is a time length from the moment at which the green light of that lane is on to the moment at which the lane flow of that lane drops to zero for the first time within a signal control cycle.

[0082] The minimum lane green light time of each lane is a sum of a time required for the total flow of that lane to pass at the lane saturation flow of that lane and a lane lost time.

[0083] If the lane saturation release time of a lane is greater than or equal to the actual green light time of this lane, the maximum lane green light time of this lane is equal to a sum of the calculated lane green light time, the detection cycle, and a predefined protection interval. If the lane saturation release time of a lane is less than the actual green light time of this lane, the maximum lane green light time of this lane is equal to a sum of the minimum lane green light time, the detection cycle, and the predefined protection interval. In some embodiments, the maximum lane green light time is calculated as follows. (1) If the lane saturation release time is greater than or equal to the actual green light time: (2) If the lane saturation release time is less than the actual green light time: Maximum lane green light time = Minimum lane green light time + Detection cycle + Predefined protection interval.

[0084] The lane green light utilization rate for each lane is the ratio of the sum of the lane saturation release time and a remaining saturation release time of that lane to the maximum lane green light time of that lane. The remaining saturation release time is the time required for a lane flow of the corresponding lane between the saturation release time and the maximum green light time to pass at the lane saturation flow. The flow between the lane saturation release time and the maximum lane green light time is derived by proportional conversion from the flow between the lane saturation release time and the calculated lane green light time.

[0085] In some embodiments, the lane green light utilization rate is calculated using Equation (1): Lane green light utilization rate = Lane saturation release time + Remaining lane saturation release time Maximun lane green light time Remaining lane saturation release time = Flow between Calculated lane green light time and Lane saturation release time Lane saturation release time ∗ Remaining conversion factor Remaining conversion factor = Maximun lane green light time − Lane saturation release time Calculated lane green light time − Lane saturation release time

[0086] In this way, by using the above method, the lane green light utilization rate is evaluated more accurately through the minimum lane green light time, the calculated lane green light time, the lane saturation release time and the maximum lane green light time.

[0087] At the step S1220, the flow direction flow rate ratios and the flow direction adjustment coefficients of the flow directions of the intersection are obtained based on the lane evaluation indicators and flow direction relationships of the lanes.

[0088] The flow direction flow rate ratio of each flow direction is equal to the lane flow rate ratio of the reference lane of that flow direction, wherein the reference lane of each flow direction is determined based on the lane green light utilization rates of the lanes corresponding to that flow direction. In some embodiments, if a flow direction includes one-way lanes, the reference lane of that flow direction is the one-way lane with the highest lane green light utilization rate in the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate in all the lanes of that flow direction.

[0089] The flow direction adjustment coefficient of each flow direction varies positively starting from 1 with the lane green time utilization rate when the lane green light utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value, and is set to a fifth predefined value when the lane idle time of the reference lane is less than a third predefined value. For example, the third predefined value is set to 5 seconds, the fourth predefined value to 0.5, and the fifth predefined value to 1.5. In some embodiments, the flow direction adjustment coefficient (denoted as ffq) is calculated as follows. (A) If the lane idle time of the reference lane is less than 5 seconds, ffq is set to the fifth predefined value; otherwise, it proceeds to (B). (B) If the lane green light utilization rate of the reference lane is less than 0.5, ffq is set to 1 and ffq is calculated using Equation (2). ffq = 1 + Lane green light utilization rate − 0.5 0.5 ∗ Fifth predefined value − 1

[0090] For example, the third predefined value is set to 5 seconds and the fourth predefined value is set to 0.5.

[0091] Thus, the embodiment of the method for evaluating a flow direction of an intersection determines the reference lane of a flow direction based on the lane green light utilization rates of the lanes of that flow direction. If the vehicles in the reference lane can pass through completely, vehicles in other lanes of the same flow direction will also pass through completely. By using the lane flow rate ratio of the reference lane as the flow direction flow rate ratio and optimizing the green light time of the flow direction based on this flow direction flow rate ratio, traffic flow efficiency is improved. The flow direction adjustment coefficient obtained from the lane idle time and the lane green light utilization rate of the reference lane is used to adjust the flow direction flow rate ratio when calculating the stage flow rate ratio, which further improves the effect of the optimized signal control time assignment scheme.

[0092] Fig. 3 illustrates a schematic flowchart of the embodiment of the method for evaluating stage green signal ratio of an intersection, which includes steps S1310 to S1330.

[0093] At the step S1310, the critical flow direction for each of the stages is determined based on the flow direction flow rate ratios of the flow directions for that stage.

[0094] The critical flow direction for each of the stages is the flow direction with the largest flow direction flow rate ratio in that stage.

[0095] At the step S1320, the stage flow rate ratio for each of the stages is obtained based on the critical flow direction for that stage.

[0096] The stage flow rate ratio for each of the stages is equal to the product of the flow direction flow rate ratio, the flow direction adjustment coefficient, and a flow direction weight coefficient of the critical flow direction for that stage. The flow direction weight coefficient is a manually configured parameter determined based on the ease of traffic in the flow direction. When the ease of traffic in the flow direction is ignored, the stage flow rate ratio for each of the stages is equal to the product of the flow direction flow rate ratio and the flow direction adjustment coefficient of the critical flow direction for that stage.

[0097] At the step S1330, the stage green signal ratio for each of the stages is obtained based on the stage flow rate ratios for the stages.

[0098] The stage green signal ratio for each of the stages is equal to a ratio of the stage flow rate ratio for that stage to a total flow rate ratio, wherein the total flow rate ratio is the sum of the stage flow rate ratios of the stages.

[0099] In some embodiments, the stage green signal ratio is calculated using Equation (3). Flow direction i = Flow direction with the largest flow direction flow rate in the caculatin stage Stage flow rate ratio = Flow direction flow rate ratio of i ∗ Flow direction adjustment coefficient of i ∗ Flow direction weight coefficient of i Stage green signal ratio = Stage flow rate ratio ∑ Stage flow rate ratios for the stages

[0100] In this way, the embodiment of the method for evaluating stage green signal ratio of an intersection obtains the stage flow rate ratios from the flow direction flow rate ratios and the flow direction adjustment coefficients, so that the stage green signal ratio calculated based on the stage flow rate ratios is more accurate, which improves the effect of the signal control time assignment scheme optimized based on the stage green signal ratio. Additionally, the stage green signal ratio is calculated by selecting the flow direction with the largest flow rate ratio in a stage, which further improves the effect of the signal control time assignment scheme optimized based on the stage green signal ratio.

[0101] Fig. 4 is a schematic flowchart of the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio, which includes steps S1410 and 1420.

[0102] At the step S1410, an optimized time length of the signal control cycle and a stage minimum green light time for each of the stages are obtained based on the signal control configuration parameters.

[0103] The signal control configuration parameters include at least historical signal time assignment schemes and the stage minimum green light time for each of the stages.

[0104] The step of obtaining the time length of the signal control cycle based on the signal control configuration parameters includes the following steps. (1) A first time length of the signal control cycle is obtained based on the signal control configuration parameters, wherein the first time length is a time length that is most frequently used by the signal control cycle in the historical signal control time assignment schemes. (2) A minimum cycle is obtained based on the stage minimum green light time of each of the stages and an all-red time, wherein the time length of the minimum cycle is the sum of the stage minimum green light times for the stages in a signal control cycle and the total all-red time in a signal control cycle. (3) The time length of the signal control cycle is optimized based on the first time length and the minimum cycle. The time length of the signal control cycle is greater than or equal to the maximum value of the first time length and the time length of the minimum cycle.

[0105] In some embodiments, the signal control configuration parameters further include a maximum cycle. If the time length of the signal control cycle obtained through the above method is greater than the time length of the maximum cycle, the time length of the signal control cycle is adjusted to the time length of the maximum cycle.

[0106] At the step S 1420, green light times for the stages are obtained based on the optimized time length of the signal control cycle, the stage green signal ratios, and the stage minimum green light times.

[0107] The green light time for each of the stages is greater than or equal to the maximum value of the stage minimum green light time for that stage and the product of the optimized time length of the signal control cycle and the stage green signal ratio for that stage.

[0108] In some embodiments, this step includes the following sub-steps. (A) the green light time is assigned for each of the stages in the signal control cycle based on the stage green signal ratios and the optimized time length of the signal control cycle and that stage is marked.

[0109] If a stage is an invalid stage, the green light time for that stage = the stage minimum green light time, and that stage is marked.

[0110] If a stage is not an invalid stage, the green light time for that stage = the optimized time length of the signal control cycle * the stage green signal ratio for that stage. If the green light time for a stage is less than the stage minimum green light time, the green light time for that stage is adjusted to the stage minimum green light time and that stage is marked.

[0111] (B) The number N of marked stages is acquired; when N = 0, assignment of the green light time is complete; otherwise, sub-steps (C), (D), and (E) are executed in sequence, and then the sub-step (B) is executed in a loop.

[0112] (C) A quotient obtained by dividing the stage green signal ratio for each of unmarked stages by the sum of the stage green signal ratios for all the unmarked stages is taken as a new stage green signal ratio for that unmarked stage, and a difference obtained by subtracting N times of the stage minimum green light time from the optimized time length of the signal control cycle is taken as a new time length of the signal control cycle.

[0113] (D) The product of the new stage green signal ratio for each of the unmarked stages and the new time length of the signal control cycle is taken as the green light time for that unmarked stage.

[0114] (E) N is set to zero, and the unmarked stages are traversed, wherein when the new green light time for a stage is less than the stage minimum green light time, the green light time for that stage is adjusted to the stage minimum green light time, that stage is marked, and the number N of marked stages is accumulated.

[0115] Thus, the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio obtains the time length of the signal control cycle based on the signal control configuration parameters, and assigns green light times of the intersection for the stages based on the stage green signal ratios, wherein the assigned green light time is greater than or equal to the configured stage minimum green light time. This improves the effect of the optimized signal time assignment scheme.

[0116] In summary, Embodiment two of the method for optimizing green light time of an intersection for a stage evaluates the lane green light utilization rate more accurately through the minimum lane green light time, the calculated lane green light time, the lane saturation release time, and the maximum lane green light time, thereby determining the accurate reference lanes of the flow directions and obtaining the accurate flow direction flow rate ratios and flow direction adjustment coefficients. Meanwhile, the stage green signal ratios are calculated by selecting the flow directions with the largest flow direction flow rate ratio, which further improves the effect of the signal time assignment scheme optimized based on the stage green signal ratios.

[0117] Device embodiments of the present application are illustrated in conjunction with Figs. 5 to 6C.

[0118] Fig. 5 shows a structure of Embodiment one of a device for optimizing green light time of an intersection for a stage, which includes: a data acquisition module 510, a flow direction traffic evaluation module 520, a stage indicator acquisition module 530, and a signal control time assignment optimization module 540.

[0119] The data acquisition module 510 is configured to acquire lane evaluation indicators and lane configuration data of lanes of an intersection. Principles and advantages of this module may be referred to the step S110 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0120] The flow direction traffic evaluation module 520 is configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of the intersection based on the lane evaluation indicators and the lane configuration data. Principles and advantages of this module may be referred to the step S120 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0121] The stage indicator acquisition module 530 is configured to obtain stage green signal ratio of the intersection for each of stages based on the flow direction flow rate ratios for the stages and the flow direction adjustment coefficients. Principles and advantages of this module may be referred to the step S130 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0122] The signal control time assignment optimization module 540 is configured to adjust a signal control time assignment scheme of the intersection based on the stage green signal ratios for the stages, wherein adjusted items of the signal control time assignment scheme include green light times for stages in a signal control cycle. Principles and advantages of this module may be referred to the step S140 of Embodiment one of the method for optimizing green light time of an intersection for a stage.

[0123] Figure 6A shows a structure of Embodiment two of the device for optimizing green light time of an intersection for a stage, which includes a data acquisition module 610, a flow direction traffic evaluation module 620, a stage indicator acquisition module 630, and a signal control time assignment optimization module 640.

[0124] The data acquisition module 610 is configured to acquire data from detectors at lane stop lines and lane configuration data for lanes of an intersection.

[0125] The flow direction traffic evaluation module 620 is configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of the intersection based on the data from the detectors at the lane stop line and the lane configuration data for the lanes. Principles and advantages of this module may be referred to the embodiment of the method for evaluating a flow direction of an interaction.

[0126] The stage indicator acquisition module 630 is configured to obtain stage green signal ratio of the intersection for each of stages based on the flow direction flow rate ratios for the stages and flow direction adjustment coefficients. Principles and advantages of this module may be referred to the embodiment of the method for evaluating stage green signal ratio of an intersection.

[0127] The signal control time assignment optimization module 640 is configured to adjust a signal control time assignment scheme of the intersection based on the stage green signal ratios for the stages, wherein adjusted items of the signal control time assignment scheme include green light times for stages in a signal control cycle. Principles and advantages of this module may be referred to the embodiment of the method for optimizing green light time of an intersection for a stage.

[0128] Figure 6B shows a structure of the flow direction traffic evaluation module 620, which includes: a lane indicator acquisition module 6210 and a flow direction indicator acquisition module 6220.

[0129] The lane indicator acquisition module 6210 is configured to obtain lane evaluation indicators of the lanes based on the data from the detectors at the lane stop line. Principles and advantages of this module may be referred to the step S1210 of the embodiment of the method for evaluating a flow direction of an intersection.

[0130] The flow direction indicator acquisition module 6220 is configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients for the flow directions of the intersection based on the lane evaluation indicators and flow direction relationships of the lanes. Principles and advantages of this module may be referred to the step S1220 of the embodiment of the method for evaluating a flow direction of an intersection.

[0131] Figure 6C shows a structure of the signal control time assignment optimization module 640, which includes: a signal control cycle acquisition module 6410 and a green light time optimization module 6420.

[0132] The signal control cycle acquisition module 6410 is configured to obtain an optimized time length of the signal control cycle and a stage minimum green light time for each of the stages based on signal control configuration parameters. Principles and advantages of this module may be referred to the step S1410 of the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio.

[0133] The green light time optimization module 6420 is configured to obtain green light times of the stages based on the time length of the signal control cycle, the stage green signal ratios, and the stage minimum green light times. Principles and advantages of this module may be referred to the step S1420 of the embodiment of the method for optimizing green light time of an intersection for a stage based on stage green signal ratio.

[0134] Another embodiment of the present application provides a traffic control system, which comprises traffic lights disposed at an intersection, a controller, and the device for optimizing green light time of an intersection for a stage provided in the above embodiments. The traffic lights and the controller are communicatively connected to the device for optimizing green light time of an intersection for a stage via communication. The controller is configured to receive the green light time of the intersection for each of the stages transmitted by the device for optimizing green light time of an intersection for a stage, and control, according to the received green light time of the intersection for each of the stages, the traffic lights to display at corresponding light colors and durations, thereby instructing travelling of traffic objects.

[0135] An embodiment of the present application further provides a computing apparatus, which is described in detail below with reference to Fig. 7.

[0136] The computing apparatus 700 includes a processor 710, a memory 720, a communication interface 730, and a bus 740.

[0137] It should be appreciated that the communication interface 730 in the computing apparatus 700 shown in this figure may be used for communication with other devices.

[0138] The processor 710 may be connected to the memory 720. The memory 720 may be used to store program codes and data. Therefore, the memory 720 may be a storage unit inside the processor 710, an external storage unit independent of the processor 710, or a component including both the storage unit inside the processor 710 and the external storage unit independent of the processor 710.

[0139] Optionally, the computing apparatus 700 may further include the bus 740. The memory 720 and the communication interface 730 may be connected to the processor 710 via the bus 740. The bus 740 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, and the like. The bus 740 may be classified as address bus, data bus, control bus, and the like. For ease of representation, only one line is shown in the figure, but this does not indicate only one bus or one type of bus.

[0140] It should be appreciated that in the embodiments of the present application, the processor 710 may employ a central processing unit (CPU). The processor may also be other general-purpose processor, a digital signal processors (DSP), an application-specific integrated circuits (ASIC), a field programmable gate arrays (FPGA) or other programmable logic devices discrete gate or transistor logic devices discrete hardware component, and the like. The general-purpose processor may be a microprocessor, any conventional processor, or the like. Alternatively, the processor 710 employs one or more integrated circuits for executing relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0141] The memory 720 may include a read-only memory and a random access memory, and provide instructions and data to the processor 710. A part of the processor 710 may also include a non-volatile random access memory. For example, the processor 710 may also store information about the type of the storage device.

[0142] When the computing apparatus 700 is running, the processor 710 executes the computer execution instructions in the memory 720 to perform the operational steps of the embodiments of the method.

[0143] It should be appreciated that the computing apparatus 700 according to the embodiments of the present application may correspond to the subject performing the methods according to the various embodiments of the present application, and the above-described and other operations and / or functions of each module in the computing apparatus 700 are respectively for implementing the corresponding processes of the methods in this embodiment. For the sake of simplicity, it will not be elaborated herein.

[0144] Those skilled in the art can appreciate that the units and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals may use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the present application.

[0145] Those skilled in the art will clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above may refer to the corresponding procedures in the foregoing method embodiments, and will not be elaborated here.

[0146] In the several embodiments provided in the present application, it should be appreciated that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not executed. Additionally, the shown or discussed mutual coupling, direct coupling, or communication connections may be indirect coupling or communication connections via some interfaces, devices, or units, which may be in electrical, mechanical, or other forms.

[0147] The units described as separate components may or may not be physically separated. Components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Part or all of the units may be selected according to actual needs to achieve the objectives of the embodiments herein.

[0148] Furthermore, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically independently, or two or more units may be integrated into one unit.

[0149] If the functions are implemented in the form of software functional units and sold or used as independent products, they may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application-in essence, or the part that makes a contribution over the prior art-may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (such as a personal computer, server, or network device) to perform all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage media include: a USB flash drive, a portable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disc, and other media capable of storing program code.

[0150] An embodiment of the present application provides a computer-readable storage medium storing thereon a computer program that, when executed by a processor, performs the operational steps of the method embodiments.

[0151] The computer storage medium of the present application embodiments may employ any combination of one or more computer-readable media. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include an electrical connection with one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In this document, a computer-readable storage medium may be any tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device.

[0152] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, in which computer-readable program code is embodied. Such a propagated data signal may be in various forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0153] Program code contained on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, and the like, or any suitable combination of the foregoing.

[0154] Computer program code for performing the operations of the present application may be written in one or more programming languages or combinations thereof, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional procedural programming languages such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0155] It should be appreciated that the above are only preferred embodiments of the present application and the technical principles employed. Those skilled in the art should be appreciated that the present application is not limited to the specific embodiments described herein, and that various obvious modifications, rearrangements, and substitutions may be made by those skilled in the art without deviating from the scope of protection of the present application. Therefore, although the present application has been described in relatively detailed terms through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, it may further include more other equivalent embodiments, all of which fall within the protection scope of the present application.

Examples

Embodiment Construction

[0045]In the following description, reference is made to "some embodiments," which describe a subset of all possible embodiments. It should be appreciated that "some embodiments" may refer to the same subset or different subsets of all possible embodiments, and may be combined with each other when there is no conflict.

[0046]In the following description, terms such as "first / second / third" or "module A, module B, module C" are used only to distinguish similar objects or different embodiments, and do not represent a specific order for the objects. It can be appreciated that, where permissible, specific orders or sequences may be interchanged so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0047]In the following description, step labels indicating steps, such as S110, S120, ..., do not necessarily mean that the steps will be executed in this order. Where permissible, the orders of the step...

Claims

1. A method for optimizing green light time of an intersection for a stage, <b>characterized by comprising: obtaining flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on lane evaluation indicators and lane configuration data of lanes of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction; obtaining stage flow rate ratio for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtaining a stage green signal ratio of each of the stages based on the stage flow rate ratios for the stages, wherein the critical flow direction for each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and optimizing green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters.

2. The method of claim 1, <b>characterized in that, optimizing green light times of the intersection for the stages based on the stage green signal ratios for stages and signal control configuration parameters comprises: obtaining a time length of a signal control cycle of a signal control time assignment scheme based on the signal control configuration parameters; optimizing the green light times for the stages based on the signal control cycle and the stage green signal ratios for the stages, wherein the green light time for each of the stages is greater than or equal to the maximum value of a stage minimum green light time for that stage and a product of the time length of the signal control cycle and the stage green signal ratio for that stage, and the signal control configuration parameters include the stage minimum green light time.

3. The method of claim 1, <b>characterized in that, the lane evaluation indicators include at least one of a lane flow rate ratio, a lane green light utilization rate, and a lane idle time; obtaining the flow direction flow rate ratios and the flow direction adjustment coefficients based on the lane evaluation indicators and the lane configuration data includes that: the flow direction flow rate ratio of each of the flow directions is equal to the lane flow rate ratio of a reference lane of that flow direction, and the flow direction adjustment coefficient of each of the flow directions is obtained based on the lane green light utilization rate and the lane idle time of the reference lane of that flow direction, wherein the lane green light utilization rate of the reference lane of each of the flow directions is the largest among lanes having the same flow direction relationship as the reference lane.

4. The method of claim 3, characterized in that, the flow direction adjustment coefficient of each of the flow directions varies positively between 1 and a fifth predefined value with the lane green time utilization rate when the lane idle time of the reference lane of that flow direction is greater than or equal to a third predefined value and the lane green time utilization rate of the reference lane of that flow direction is greater than or equal to a fourth predefined value.

5. The method of claim 3, <b>characterized in that, if a flow direction includes one-way lanes, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among the one-way lanes of that flow direction; otherwise, the reference lane of that flow direction is the lane with the highest lane green light utilization rate among all lanes of that flow direction.

6. The method of claim 3, <b>characterized in that, the lane green time utilization rate of each of the lanes is a ratio of the sum of a lane saturation release time of that lane and a remaining saturation release time of that lane to a maximum lane green time of that lane, wherein the remaining saturation release time of each of the lanes is a time required for a lane flow of that lane after the saturation release time and before the maximum lane green light time to pass at a lane saturation flow of that lane; and the lane saturation release time of each of the lanes is a time length from a moment at which a green light of that lane is on to a moment at which the lane flow of that lane drops to the lane saturation flow for the first time within a signal control cycle.

7. The method of claim 6, characterized in that, the lane saturation flow of each of the lanes is a value at a first quantile, sorted from low to high, of non-zero lane flows of that lane within an evaluation period, and each of the lane flows is a flow detected by a lane detector within one detection cycle.

8. A device for optimizing green light time of an intersection for a stage, <b>characterized by comprising: a flow direction traffic evaluation module configured to obtain flow direction flow rate ratios and flow direction adjustment coefficients of flow directions of an intersection based on detector data and lane configuration data of the intersection, wherein the flow direction adjustment coefficient of each of the flow directions changes positively with a saturation level of that flow direction, and the detector data at least includes lane flow of each lane of the intersection in detection cycles; a stage indicator acquisition module configured to obtain stage flow rate ratio of the intersection for each of stages based on a product of the flow direction flow rate ratio and the flow direction adjustment coefficient of a critical flow direction of the intersection for that stage, and obtain stage green signal ratio for each of the stages based on the stage flow rate ratios for the stages, wherein the stage flow rate ratio for each of the stages is in direct proportion to the product for that stage, and the critical flow direction of each of the stages is a flow direction with the largest flow direction flow rate ratio in that stage; and a signal control time assignment optimization module configured to optimize green light times of the intersection for the stages based on the stage green signal ratios for the stages and signal control configuration parameters.

9. A computing apparatus, <b>characterized by comprising: a bus; a communication interface connected to the bus; at least one processor connected to the bus; and at least one memory connected to the bus and storing program instructions that, when executed by the at least one processor, cause the at least one processor to perform the method according to any one of claims 1-7.

10. A computer-readable storage medium characterized by storing thereon program instructions that, when executed by a computer, cause the computer to perform the method according to any one of claims 1-7.

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