Signal lamp control method for step-by-step generation of phase structure phase scheme

Abstract

The invention discloses a signal lamp control method for step-by-step generation of a phase structure phase scheme, and belongs to the technical field of intelligent traffic signal control. In order to improve the passing efficiency, the method comprises the steps of constructing a phase generation method of a bottom layer, considering lane group setting and lamp group setting to generate motor vehicle phase steering information, determining a priority selection signal lamp type, and generating a motor vehicle phase combination and a pedestrian phase; constructing a basic stage set generation method of a middle layer, adding traffic flow conflict information to traffic flow, generating a basic vehicle stage set through motor vehicle phase combination, and combining pedestrian phases with the basic vehicle stage set to generate a basic stage set; and constructing a cycle stage combination scheme generation method of a top layer, carrying out combination screening on the basic stage sets to obtain a feasible cycle stage combination scheme set, solving the sum of key flow directions and flow ratios by utilizing a linear programming model, and screening the minimum sum of the key flow directions and flow ratios as a target to obtain an optimal cycle stage combination scheme. The traffic efficiency of the intersection is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent traffic signal control, and in particular relates to a signal light control method for step-by-step generation of a phase structure scheme. Background Art

[0002] Traffic signal phase optimization is one of the key contents of signal optimization, and it is a bridge connecting intersection traffic organization channelization design and signal timing optimization. Phase optimization needs to determine which phases there are, which phases will be released at the same time, and the number of releases. Phase optimization can reduce the conflict between vehicles in different directions at the intersection by dividing the phases reasonably, and improve traffic efficiency at the same time. The key is to control the number of phases. The number of phases determines traffic safety and traffic efficiency. The more phases, the less conflict, but the phase loss time will also increase, and vice versa.

[0003] Currently, signal phase optimization design is performed based on manual experience and conflict rules, and there is an urgent need for a complete and quantifiable method for the design process. Summary of the invention

[0004] The problem to be solved by the present invention is to improve the traffic efficiency, and a signal light control method for step-by-step generation of a phase structure scheme is proposed.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions: A signal light control method for step-by-step generation of a phase structure phase scheme comprises the following steps: S1. Construct the underlying phase generation method, including the motor vehicle phase generation method and the pedestrian phase generation method, consider the lane group setting and the light group setting, generate the motor vehicle phase steering information, and then determine the priority signal light type according to the light group and the motor vehicle phase steering information, and generate the motor vehicle phase combination and the pedestrian phase; S2. Construct a basic phase set generation method at the middle level, first add traffic flow conflict information to the traffic flow, then generate a basic vehicle phase set by combining motor vehicle phases, and combine pedestrian phases with the basic vehicle phase set to generate a basic phase set; S3. Construct a top-level cycle phase combination scheme generation method by combining the basic phase sets and then screening to obtain a feasible cycle phase combination scheme set. Then use the linear programming model to solve the sum of the key flow ratios, and finally screen the sum of the key flow ratios as the minimum to obtain the optimal cycle phase combination scheme.

[0006] Furthermore, the specific implementation method of constructing the motor vehicle phase generation method in step S1 includes the following steps: S1.1. Extracting steering information contained in the motor vehicle phase; S1.1.1. Perform turn merging according to lane group settings: merge the turn information contained in each lane into a turn set, set an entry lane group to include a first turn set list A, perform a union operation on the turn sets with intersections in the first turn set list A, and obtain the first turn information phase_bases-1; S1.1.2. Merge turns according to the light group settings: merge the turn information contained in each light group into a turn set, set an entrance road light group to contain the second turn set list B, if the turn set in phase_bases-1 exists in the second turn set list B, skip it, otherwise determine whether the turn set in phase_bases-1 is a true subset of the second turn set list B, if so, add the parent set in the second turn set list B to phase_base-1, and perform a union operation on the turn sets with intersections in phase_base-1 to obtain the second turn information phase_bases-2; S1.1.3. Check whether there is a U-turn set {'U'} and a left-turn set {'L'} released separately in phase_bases-2. If so, merge them into a special demand set {'U', 'L'}, and obtain the third turning information phase_base-3 after merging. S1.2. Based on the steering information obtained in step S1.1, the light group is screened to obtain a motor vehicle phase combination; S1.2.1. Set the phase type classification rules for U-turn and left turn, and then set the current direction light group to avoid releasing the opposite straight-moving vehicles at the same time for the U-turn protection phase and the left turn protection phase; set the current direction light group to release the opposite straight-moving vehicles at the same time for the U-turn permission phase and the left turn permission phase; S1.2.2. Use all elements in the second turn set list B to generate a third turn set list C, filter the turn set in accordance with the third turn information phase_base-3 obtained in step S1.1, to form a light group turn set list light_bases; S1.2.3. Select the best light group combination from the light group turn set list obtained in step S1.2.2 to become the motor vehicle phase; the selection method is to directly select if there is only one light group combination, and to compare if there are multiple groups. The comparison requirement is that if there are circular light balls in both the current direction and the opposite direction and the left turn in both the current direction and the opposite direction are both permissive phases, the circular light ball is given priority, otherwise the arrow light arrow is given priority.

[0007] Furthermore, the phase type classification rule for the U-turn is set in step S1.1 to satisfy the U-turn protection phase if the number of U-turn lanes is ≥2 or the number of opposite straight lanes is ≥4, otherwise it is a U-turn permission phase.

[0008] Furthermore, the phase type classification rule for the left turn is set in step S1.1 as follows: The phase is a left-turn protection phase if the number of left-turn lanes is ≥ 2, the number of oncoming through lanes is ≥ 4, the speed of oncoming through vehicles is ≥ 72 km / h, or when the number of oncoming through lanes is equal to 1, the left-turn flow rate × the target through flow rate is ≥ 50,000 pcu / h, or when the number of oncoming through lanes is equal to 2 or 3, the left-turn flow rate × the target through flow rate is ≥ 100,000 pcu / h. When the above rules are not met or the left-turn flow rate ≤ 60pcu / h, or when the number of opposite through lanes is equal to 1, the left-turn flow rate × the target through flow rate < 50000pcu / h, or when the number of opposite through lanes is equal to 2 or 3, the left-turn flow rate × the target through flow rate < 100000pcu / h, it is a left-turn permitted phase.

[0009] Furthermore, step S1 also includes a method for generating a pedestrian phase, in which a pedestrian phase is set for each pedestrian light. If there is a second street crossing, the direction of the traffic flow and the order of passing the signal lights are used to distinguish whether the pedestrian light is at the entrance or exit, and the pedestrian phase is obtained.

[0010] Furthermore, the specific implementation method of step S2 includes the following steps: S2.1. Add traffic flow conflict information to the traffic flow; S2.1.1. Input the basic traffic flow conflict table; S2.1.2. Based on the U-turn and left turn signal light types, if there is a traffic flow in a U-turn protection phase or a left turn protection phase, add traffic flow conflict information to the traffic flow and the opposite straight traffic flow; S2.1.3. Based on the light group settings, if there is an arrow light for a left turn or a U-turn, add traffic flow conflict information to the traffic flow and the opposite straight traffic flow; S2.1.4. Based on the lane setting, if there is a through lane on the left side of the U-turn lane, add traffic flow conflict information to the U-turn traffic flow in this direction and the through traffic flow in the opposite direction; S2.2. Generate a basic vehicle phase set by combining vehicle phases; S2.2.1. Set the motor vehicle phase combination to exclude the right turn dedicated arrow light phase, and generate a potential phase set -1 for the motor vehicle phase combination; S2.2.2. Determine whether there is a conflict between all traffic flows included in the potential stage set-1. If there is a conflict, delete the conflicting traffic flows to obtain the potential stage set-2. S2.2.3. Screening the stages in the potential stage set-2, deleting a stage subset of the stages in the potential stage set-2, and forming a potential stage set-3; S2.2.4. Add a right-turn dedicated arrow light to the potential phase set-3, and the right-turn phase is released at the same time as the phase of the current direction to form a basic vehicle phase set; S2.3. After judging the pedestrian phase, the pedestrian phase is combined with the basic vehicle phase set to generate a basic phase set; S2.3.1. Determine whether there is an independent pedestrian phase. If so, bind all pedestrian phases and do not release pedestrian phases in other phases. Otherwise, continue to determine the parent phase and modified phase of the pedestrian phase. If the parent phase of the pedestrian phase exists and the modified phase of the pedestrian phase does not exist, release the pedestrian phase. S2.3.2. Combine the basic vehicle phase set with the pedestrian phase to obtain the basic phase set.

[0011] Furthermore, the determination method of the pedestrian independent stage in step S2.3.1 is: If the total pedestrian flow is ≥3000 ped / h or the pedestrian flow of at least three branches is ≥800 ped / h or the pedestrian flow of at least two directions of diagonal crossing is ≥800 ped / h or there is no pedestrian flow that can follow motor vehicles, then the pedestrian independent stage is set; Otherwise, pedestrians will be released at the same time as motor vehicles going straight in the same entrance direction.

[0012] Furthermore, the method for determining the parent phase and the modified phase of the pedestrian phase in step S2.3.1 is as follows: For a pedestrian crossing phase, the parent phase of the pedestrian phase is set to the phase of the straight-moving motor vehicle in the clockwise vertical direction; For the secondary pedestrian crossing phase, the parent phase of the pedestrian phase of the entrance is set to the phases of all motor vehicles in the opposite and vertical directions, and the correction phase of the pedestrian phase is set to the phases of all motor vehicles in this direction; For the secondary pedestrian crossing phase, the parent phase of the pedestrian phase of the exit lane is set to the phases of all other motor vehicles, and the correction phase of the pedestrian phase is the phase of motor vehicles that include the phases of motor vehicles going straight in the opposite direction and the phases of motor vehicles that pass through the exit lane and use arrow lights.

[0013] Furthermore, the specific implementation method of step S3 includes the following steps: S3.1. Combine the basic stage set, set the general stage number to 2 ~ (number of forks + 2), generate a potential cycle stage combination plan - 1, the number of forks is the number of branches and forks at the intersection, which is equal to the number of branches at the intersection; S3.2. In the potential cycle phase combination scheme-1, for each phase, based on the parent phase of the pedestrian phase and the modified phase of the pedestrian phase, the pedestrian phase is selected to join the phase to generate the potential cycle phase combination scheme-2; then, it is determined whether the potential cycle phase combination scheme-2 covers all motor vehicle phases and pedestrian phases, and a feasible cycle phase combination scheme set is obtained after screening; S3.3. For the set of feasible cycle phase combination schemes, the sum of the critical flow rate ratios is solved through the linear programming model, and then the optimal cycle phase combination scheme is selected with the goal of minimizing the sum of the critical flow rate ratios.

[0014] Furthermore, the specific implementation method of step S3.3 includes the following steps: S3.3.1. Set the objective function to minimize the sum of the key flow ratios, expressed as: ; in, For the i The flow ratio of key lane groups in each stage, n is the number of cycle stages; S3.3.2. Set the constraint condition that the flow ratio of the key flow direction in each stage should be greater than the flow ratio of each traffic flow, expressed as: ; in, is the flow ratio of traffic flow k, is the set of stages of traffic flow k.

[0015] Beneficial effects of the present invention: The signal light control method for step-by-step generation of a phase scheme of a stage structure described in the present invention provides a complete, clear and feasible distribution generation method of a phase scheme of a stage structure, thereby automatically completing the generation of the phase scheme and avoiding complete reliance on manual experience for design.

[0016] The signal light control method of the stage structure phase scheme step-by-step generation described in the present invention proposes a convenient and efficient key flow direction flow ratio calculation model. The phase generation result can not only avoid traffic flow conflicts, but also maximize the use of green light time and improve the traffic efficiency of intersections. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention provides a flow chart of a signal light control method generated step by step by a phase structure phase scheme. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the specific embodiments described are only part of the embodiments of the present invention, rather than all of the specific embodiments. The components of the specific embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations, and the present invention can also have other embodiments.

[0019] Therefore, the following detailed description of the specific embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected specific embodiments of the present invention. Based on the specific embodiments of the present invention, all other specific embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0020] In order to further understand the content, features and effects of the present invention, the following specific implementation methods are given as examples, and the attached Figure 1 The detailed instructions are as follows:

[0021] Embodiment 1: A signal light control method for step-by-step generation of a phase structure phase scheme comprises the following steps: S1. Construct the underlying phase generation method, including the motor vehicle phase generation method and the pedestrian phase generation method, consider the lane group setting and the light group setting, generate the motor vehicle phase steering information, and then determine the priority signal light type according to the light group and the motor vehicle phase steering information, and generate the motor vehicle phase combination and the pedestrian phase; Furthermore, the specific implementation method of constructing the motor vehicle phase generation method in step S1 includes the following steps: S1.1. Extracting steering information contained in the motor vehicle phase; S1.1.1. Perform turn merging according to lane group settings: merge the turn information contained in each lane into a turn set, set an entry lane group to include a first turn set list A, perform a union operation on the turn sets with intersections in the first turn set list A, and obtain the first turn information phase_bases-1; S1.1.2. Merge turns according to the light group settings: merge the turn information contained in each light group into a turn set, set an entrance road light group to contain the second turn set list B, if the turn set in phase_bases-1 exists in the second turn set list B, skip it, otherwise determine whether the turn set in phase_bases-1 is a true subset of the second turn set list B, if so, add the parent set in the second turn set list B to phase_base-1, and perform a union operation on the turn sets with intersections in phase_base-1 to obtain the second turn information phase_bases-2; S1.1.3. Check whether there is a U-turn set {'U'} and a left-turn set {'L'} released separately in phase_bases-2. If so, merge them into a special demand set {'U', 'L'}, and obtain the third turning information phase_base-3 after merging. Furthermore, the phase type classification rule of the U-turn is set in step S1.1 to be a U-turn protection phase if the number of U-turn lanes is ≥ 2 or the number of opposite straight lanes is ≥ 4, otherwise it is a U-turn permission phase; Furthermore, the phase type classification rule for the left turn is set in step S1.1 as follows: The phase is a left-turn protection phase if the number of left-turn lanes is ≥ 2, the number of oncoming through lanes is ≥ 4, the speed of oncoming through vehicles is ≥ 72 km / h, or when the number of oncoming through lanes is equal to 1, the left-turn flow rate × the target through flow rate is ≥ 50,000 pcu / h, or when the number of oncoming through lanes is equal to 2 or 3, the left-turn flow rate × the target through flow rate is ≥ 100,000 pcu / h. When the above rules are not met or the left-turn flow rate is ≤60pcu / h, or when the number of opposite through lanes is equal to 1, the left-turn flow rate × the target through flow rate <50000pcu / h, or when the number of opposite through lanes is equal to 2 or 3, the left-turn flow rate × the target through flow rate <100000pcu / h, it is a left-turn permission phase; S1.2. Based on the steering information obtained in step S1.1, the light group is screened to obtain a motor vehicle phase combination; S1.2.1. Set the phase type classification rules for U-turn and left turn, and then set the current direction light group to avoid releasing the opposite straight-moving vehicles at the same time for the U-turn protection phase and the left turn protection phase; set the current direction light group to release the opposite straight-moving vehicles at the same time for the U-turn permission phase and the left turn permission phase; S1.2.2. Use all elements in the second turn set list B to generate a third turn set list C, filter the turn set in accordance with the third turn information phase_base-3 obtained in step S1.1, to form a light group turn set list light_bases; S1.2.3. Select the best light group combination from the light group turn set list obtained in step S1.2.2 to become the motor vehicle phase; the selection method is to directly select if there is only one light group combination, and to compare if there are multiple groups. The comparison requirement is that if there are round light balls in both the current direction and the opposite direction and the left turn in both the current direction and the opposite direction are both permissive phases, the round light ball is preferred, otherwise the arrow light is preferred; Furthermore, step S1 also includes a method for generating a pedestrian phase, wherein a pedestrian phase is set for each pedestrian light, and if there is a second street crossing, the direction of the traffic flow and the order of passing the signal lights are used to distinguish whether the pedestrian light is in the entrance lane or the exit lane, and the pedestrian phase is obtained; Furthermore, the phases in step S1 are divided into two categories: vehicle phases and pedestrian phases. The phases determine which traffic flows can be released at the same time by controlling the light groups. The generation of phases needs to meet the following requirements: Only when the time right of way of traffic flow in the same direction is completely consistent can it become a phase; According to the lane group and light group settings, it is determined whether the motor vehicle traffic flow in the same direction has completely consistent right of way. The time right of way of all turning traffic flows contained in the same lane should be consistent; if the light group only supports the release of certain turning traffic flows together, their time right of way should be consistent; in addition, there are some special cases, such as if some traffic flows are suitable for being released together, they are placed in one phase; Phase control is achieved by controlling the light group to control traffic flow. The motor vehicle light group is divided into two types: round pancake lights (ball type) and turn arrow lights (arrow type). The same group of turn traffic flow has different light group combinations. The selection of light groups should not only consider the release relationship of traffic flow in this direction, but also the release relationship between traffic flow in this direction and traffic flow in the opposite direction; Each pedestrian light group constitutes a phase. Pedestrian crossing is divided into single crossing and double crossing. Single crossing corresponds to one light group, and double crossing corresponds to two light groups. The phase set must cover all traffic flows.

[0022] S2. Construct a basic phase set generation method at the middle level, first add traffic flow conflict information to the traffic flow, then generate a basic vehicle phase set by combining motor vehicle phases, and combine pedestrian phases with the basic vehicle phase set to generate a basic phase set; Furthermore, the specific implementation method of step S2 includes the following steps: S2.1. Add traffic flow conflict information to the traffic flow; S2.1.1. Input the basic traffic flow conflict table; S2.1.2. Based on the U-turn and left turn signal light types, if there is a traffic flow in a U-turn protection phase or a left turn protection phase, add traffic flow conflict information to the traffic flow and the opposite straight traffic flow; S2.1.3. Based on the light group settings, if there is an arrow light for a left turn or a U-turn, add traffic flow conflict information to the traffic flow and the opposite straight traffic flow; S2.1.4. Based on the lane setting, if there is a through lane on the left side of the U-turn lane, add traffic flow conflict information to the U-turn traffic flow in this direction and the through traffic flow in the opposite direction; S2.2. Generate a basic vehicle phase set by combining vehicle phases; S2.2.1. Set the motor vehicle phase combination to exclude the right turn dedicated arrow light phase, and generate a potential phase set -1 for the motor vehicle phase combination; S2.2.2. Determine whether there is a conflict between all traffic flows included in the potential stage set-1. If there is a conflict, delete the conflicting traffic flows to obtain the potential stage set-2. S2.2.3. Screening the stages in the potential stage set-2, deleting a stage subset of the stages in the potential stage set-2, and forming a potential stage set-3; S2.2.4. Add a right-turn dedicated arrow light to the potential phase set-3, and the right-turn phase is released at the same time as the phase of the current direction to form a basic vehicle phase set; S2.3. After judging the pedestrian phase, the pedestrian phase is combined with the basic vehicle phase set to generate a basic phase set; S2.3.1. Determine whether there is an independent pedestrian phase. If so, bind all pedestrian phases and do not release pedestrian phases in other phases. Otherwise, continue to determine the parent phase and modified phase of the pedestrian phase. If the parent phase of the pedestrian phase exists and the modified phase of the pedestrian phase does not exist, release the pedestrian phase. Furthermore, the determination method of the pedestrian independent stage in step S2.3.1 is: If the total pedestrian flow is ≥3000 ped / h or the pedestrian flow of at least three branches is ≥800 ped / h or the pedestrian flow of at least two directions of diagonal crossing is ≥800 ped / h or there is no pedestrian flow that can follow motor vehicles, then the pedestrian independent stage is set; Otherwise, pedestrians will be released at the same time as the motor vehicles going straight in the same entrance direction; Furthermore, the method for determining the parent phase and the modified phase of the pedestrian phase in step S2.3.1 is as follows: For a pedestrian crossing phase, the parent phase of the pedestrian phase is set to the phase of the straight-moving motor vehicle in the clockwise vertical direction; For the secondary pedestrian crossing phase, the parent phase of the pedestrian phase of the entrance is set to the phases of all motor vehicles in the opposite and vertical directions, and the correction phase of the pedestrian phase is set to the phases of all motor vehicles in this direction; For the secondary pedestrian crossing phase, the parent phase of the pedestrian phase of the exit lane is set to the phases of all other motor vehicles, and the correction phase of the pedestrian phase is the phase of the motor vehicle that is going straight in the opposite direction and the phase of the motor vehicle that passes the exit lane and uses the arrow light; S2.3.2. Combine the basic vehicle phase set with the pedestrian phase to obtain the basic phase set; Furthermore, a phase is a combination of a motor vehicle phase and a pedestrian phase, and the traffic flows released in a basic phase cannot conflict. The generation of a basic phase needs to meet the following requirements: There should be no conflict in the traffic flows released during the basic phase; The basic phase tries to include more non-conflicting traffic flows to make better use of the green light time.

[0023] S3. Construct a top-level cycle phase combination scheme generation method by combining the basic phase sets and then screening to obtain a feasible cycle phase combination scheme set. Then use the linear programming model to solve the sum of the key flow ratios, and finally screen the sum of the key flow ratios as the minimum to obtain the optimal cycle phase combination scheme.

[0024] Furthermore, the specific implementation method of step S3 includes the following steps: S3.1. Combine the basic stage set, set the general stage number to 2 ~ (number of forks + 2), generate a potential cycle stage combination plan - 1, the number of forks is the number of branches and forks at the intersection, which is equal to the number of branches at the intersection; S3.2. In the potential cycle phase combination scheme-1, for each phase, based on the parent phase of the pedestrian phase and the modified phase of the pedestrian phase, the pedestrian phase is selected to join the phase to generate the potential cycle phase combination scheme-2; then, it is determined whether the potential cycle phase combination scheme-2 covers all motor vehicle phases and pedestrian phases, and a feasible cycle phase combination scheme set is obtained after screening; S3.3. For the set of feasible cycle phase combination schemes, the sum of the critical flow rate ratios is solved through the linear programming model, and then the optimal cycle phase combination scheme is selected with the goal of minimizing the sum of the critical flow rate ratios.

[0025] Furthermore, the specific implementation method of step S3.3 includes the following steps: S3.3.1. Set the objective function to minimize the sum of the key flow ratios, expressed as: ; in, For the i The flow ratio of key lane groups in each stage, n is the number of cycle stages; S3.3.2. Set the constraint condition that the flow ratio of the key flow direction in each stage should be greater than the flow ratio of each traffic flow, expressed as: ; in, is the flow ratio of traffic flow k, is the set of stages of traffic flow k.

[0026] Furthermore, the cycle phase plan is formed by screening the basic phase set. There may be multiple sets of cycle phase plans, and the best plan needs to be selected. The generation of the cycle phase plan needs to meet the following requirements: All phases must be released at least once within the cycle; The optimal cycle phase combination scheme is selected with the goal of minimizing the sum of the flow ratios of the key lane group.

[0027] The key technical points and points to be protected of the present invention are: 1. A complete set of logical steps for the step-by-step generation method of the phase scheme of the phase structure, including: the bottom-level phase generation method, the middle-level basic phase generation method, and the top-level periodic phase scheme generation method.

[0028] 2. The technical methods that have been clarified in the solution steps and key step methods of the three methods (bottom-level phase generation method, middle-level basic phase generation method and top-level cycle phase solution generation method).

[0029] 3. Linear programming model of the sum of key flow ratios.

[0030] The abbreviations and key terms used in the present invention are defined as follows: Time right of way: When a vehicle obtains the green light at an intersection, it obtains the time right of way, and the vehicle can pass through the intersection during this period of time.

[0031] Stage structure: a signal cycle plan is divided into multiple stages according to the time right of way of each traffic flow.

[0032] Ball-type light: a circular light. When the circular light is green, all traffic flows in that direction are granted the time right of way.

[0033] Arrow-type lights: Turn arrow lights, including U-turn arrow lights, left turn arrow lights, straight arrow lights and right turn arrow lights. When the arrow light is green, the turning traffic flow obtains absolute right of way and other conflicting traffic flows are not allowed to pass at the same time.

[0034] Phase (signal phase): The time when one or several traffic flows obtain the right of way at exactly the same time within a traffic signal cycle is called a signal phase.

[0035] Stage: A stage consists of one or several phases, and the time right of way of all traffic flows in the stage remains unchanged.

[0036] Cycle phase plan: The phase plan contained in a signal cycle.

[0037] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0038] Although the present application has been described above with reference to specific embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various features in the specific embodiments disclosed in the present application may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A signal light control method for step-by-step generation of a phase structure phase scheme, characterized in that: The steps include: S1. Construct the underlying phase generation method, including the motor vehicle phase generation method and the pedestrian phase generation method, consider the lane group setting and the light group setting, generate the motor vehicle phase steering information, and then determine the priority signal light type according to the light group and the motor vehicle phase steering information, and generate the motor vehicle phase combination and the pedestrian phase; S2. Construct a basic phase set generation method at the middle level, first add traffic flow conflict information to the traffic flow, then generate a basic vehicle phase set by combining motor vehicle phases, and combine pedestrian phases with the basic vehicle phase set to generate a basic phase set; S3. Construct a top-level cycle phase combination scheme generation method by combining the basic phase sets and then screening to obtain a feasible cycle phase combination scheme set. Then use the linear programming model to solve the sum of the key flow ratios, and finally screen the sum of the key flow ratios as the minimum to obtain the optimal cycle phase combination scheme.

2. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 1, characterized in that: The specific implementation method of constructing the motor vehicle phase generation method in step S1 includes the following steps: S1.

1. Extracting steering information contained in the motor vehicle phase; S1.1.

1. Perform turn merging according to lane group settings: merge the turn information contained in each lane into a turn set, set an entry lane group to include a first turn set list A, perform a union operation on the turn sets with intersections in the first turn set list A, and obtain the first turn information phase_bases-1; S1.1.

2. Merge turns according to the light group settings: merge the turn information contained in each light group into a turn set, set an entrance road light group to contain the second turn set list B, if the turn set in phase_bases-1 exists in the second turn set list B, skip it, otherwise determine whether the turn set in phase_bases-1 is a true subset of the second turn set list B, if so, add the parent set in the second turn set list B to phase_base-1, and perform a union operation on the turn sets with intersections in phase_base-1 to obtain the second turn information phase_bases-2; S1.1.

3. Check whether there is a U-turn set {'U'} and a left-turn set {'L'} released separately in phase_bases-2. If so, merge them into a special demand set {'U', 'L'}, and obtain the third turning information phase_base-3 after merging. S1.

2. Based on the steering information obtained in step S1.1, the light group is screened to obtain a motor vehicle phase combination; S1.2.

1. Set the phase type classification rules for U-turn and left turn, and then set the current direction light group to avoid releasing the opposite straight-moving vehicles at the same time for the U-turn protection phase and the left turn protection phase; set the current direction light group to release the opposite straight-moving vehicles at the same time for the U-turn permission phase and the left turn permission phase; S1.2.

2. Use all elements in the second turn set list B to generate a third turn set list C, filter the turn set in accordance with the third turn information phase_base-3 obtained in step S1.1, to form a light group turn set list light_bases; S1.2.

3. Select the best light group combination from the light group turn set list obtained in step S1.2.2 to become the motor vehicle phase; the selection method is to directly select if there is only one light group combination, and to compare if there are multiple groups. The comparison requirement is that if there are circular light balls in both the current direction and the opposite direction and the left turn in both the current direction and the opposite direction are both permissive phases, the circular light ball is given priority, otherwise the arrow light arrow is given priority.

3. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 2, characterized in that: The phase type classification rule for setting the U-turn in step S1.1 is that if the number of U-turn lanes is ≥2 or the number of opposite straight lanes is ≥4, it is a U-turn protection phase, otherwise it is a U-turn permission phase.

4. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 3, characterized in that: The phase type classification rule for setting the left turn in step S1.1 is: The phase is a left-turn protection phase if the number of left-turn lanes is ≥ 2, the number of oncoming through lanes is ≥ 4, the speed of oncoming through vehicles is ≥ 72 km / h, or when the number of oncoming through lanes is equal to 1, the left-turn flow rate × the target through flow rate is ≥ 50,000 pcu / h, or when the number of oncoming through lanes is equal to 2 or 3, the left-turn flow rate × the target through flow rate is ≥ 100,000 pcu / h. When the above rules are not met or the left-turn flow rate is ≤60pcu / h or when the number of opposite through lanes is 1, the left-turn flow rate × the target through flow rate <50000pcu / h or when the number of opposite through lanes is 2 or 3, the left-turn flow rate × the target through flow rate <100000pcu / h: left turn permission phase.

5. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 4, characterized in that: Step S1 also includes a method for generating a pedestrian phase. A pedestrian phase is set for each pedestrian light. If there is a second street crossing, the direction of the traffic flow and the order of passing the signal lights are used to distinguish whether the pedestrian light is at the entrance or exit, and the pedestrian phase is obtained.

6. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 5, characterized in that: The specific implementation method of step S2 includes the following steps: S2.

1. Add traffic flow conflict information to the traffic flow; S2.1.

1. Input the basic traffic flow conflict table; S2.1.

2. Based on the U-turn and left turn signal light types, if there is a traffic flow in a U-turn protection phase or a left turn protection phase, add traffic flow conflict information to the traffic flow and the opposite straight traffic flow; S2.1.

3. Based on the light group settings, if there is an arrow light for a left turn or a U-turn, add traffic flow conflict information to the traffic flow and the opposite straight traffic flow; S2.1.

4. Based on the lane setting, if there is a through lane on the left side of the U-turn lane, add traffic flow conflict information to the U-turn traffic flow in this direction and the through traffic flow in the opposite direction; S2.

2. Generate a basic vehicle phase set by combining vehicle phases; S2.2.

1. Set the motor vehicle phase combination to exclude the right turn dedicated arrow light phase, and generate a potential phase set -1 for the motor vehicle phase combination; S2.2.

2. Determine whether there is a conflict between all traffic flows included in the potential stage set-1. If there is a conflict, delete the conflicting traffic flows to obtain the potential stage set-2. S2.2.

3. Screening the stages in the potential stage set-2, deleting a stage subset of the stages in the potential stage set-2, and forming a potential stage set-3; S2.2.

4. Add a right-turn dedicated arrow light to the potential phase set-3, and the right-turn phase is released at the same time as the phase of the current direction to form a basic vehicle phase set; S2.

3. After judging the pedestrian phase, the pedestrian phase is combined with the basic vehicle phase set to generate a basic phase set; S2.3.

1. Determine whether there is an independent pedestrian phase. If so, bind all pedestrian phases and do not release pedestrian phases in other phases. Otherwise, continue to determine the parent phase and modified phase of the pedestrian phase. If the parent phase of the pedestrian phase exists and the modified phase of the pedestrian phase does not exist, release the pedestrian phase. S2.3.

2. Combine the basic vehicle phase set with the pedestrian phase to obtain the basic phase set.

7. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 6, characterized in that: The determination method of the pedestrian independent stage in step S2.3.1 is: If the total pedestrian flow is ≥3000 ped / h or the pedestrian flow of at least three branches is ≥800 ped / h or the pedestrian flow of at least two directions of diagonal crossing is ≥800 ped / h or there is no pedestrian flow that can follow motor vehicles, then the pedestrian independent stage is set; Otherwise, pedestrians will be released at the same time as motor vehicles going straight in the same entrance direction.

8. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 7, characterized in that: The method for determining the parent phase and the modified phase of the pedestrian phase in step S2.3.1 is: For a pedestrian crossing phase, the parent phase of the pedestrian phase is set to the phase of the straight-moving motor vehicle in the clockwise vertical direction; For the secondary pedestrian crossing phase, the parent phase of the pedestrian phase of the entrance is set to the phases of all motor vehicles in the opposite and vertical directions, and the correction phase of the pedestrian phase is set to the phases of all motor vehicles in this direction; For the secondary pedestrian crossing phase, the parent phase of the pedestrian phase of the exit lane is set to the phases of all other motor vehicles, and the correction phase of the pedestrian phase is the phase of motor vehicles that include the phases of motor vehicles going straight in the opposite direction and the phases of motor vehicles that pass through the exit lane and use arrow lights.

9. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 8, characterized in that: The specific implementation method of step S3 includes the following steps: S3.

1. By combining the basic stage set, set the general stage number to 2 ~ (number of forks + 2), generate a potential cycle stage combination plan - 1, the number of forks is the number of branches of the intersection, which is equal to the number of branches of the intersection; S3.

2. In the potential cycle phase combination scheme-1, for each phase, based on the parent phase of the pedestrian phase and the modified phase of the pedestrian phase, the pedestrian phase is selected to join the phase to generate the potential cycle phase combination scheme-2; then, it is determined whether the potential cycle phase combination scheme-2 covers all motor vehicle phases and pedestrian phases, and a feasible cycle phase combination scheme set is obtained after screening; S3.

3. For the set of feasible cycle phase combination schemes, the sum of the critical flow rate ratios is solved through the linear programming model, and then the optimal cycle phase combination scheme is selected with the goal of minimizing the sum of the critical flow rate ratios.

10. The signal light control method of step-by-step generation of a phase structure phase scheme according to claim 9, characterized in that: The specific implementation method of step S3.3 includes the following steps: S3.3.

1. Set the objective function to minimize the sum of the key flow ratios, expressed as: ； in, For the i The flow ratio of key lane groups in each stage, n is the number of cycle stages; S3.3.

2. Set the constraint condition that the flow ratio of the key flow direction in each stage should be greater than the flow ratio of each traffic flow, expressed as: ； in, is the flow ratio of traffic flow k, is the set of stages of traffic flow k.

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