A signal lamp control method for step-by-step generation of a stage structure phase scheme

Abstract

A signal light control method for step-by-step generation of a stage structure phase scheme belongs to the technical field of intelligent traffic signal control. To improve traffic efficiency, the present invention includes constructing a phase generation method at the bottom layer, generating motor vehicle phase steering information by considering lane group settings and light group settings, determining the preferred signal light type, generating motor vehicle phase combinations and pedestrian phases; constructing a basic stage set generation method at the middle layer, adding traffic flow conflict information to the traffic flow, generating a basic vehicle stage set through the motor vehicle phase combinations, and combining the pedestrian phases with the basic vehicle stage set to generate a basic stage set; constructing a cycle stage combination scheme generation method at the top layer, obtaining a set of feasible cycle stage combination schemes by combining and screening the basic stage set, and then using a linear programming model to solve for the sum of the key flow ratios to screen for the minimum sum of the key flow ratios as the target to obtain an optimal cycle stage combination scheme. The present invention improves the traffic efficiency at intersections.

Description

Technical Field

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

[0002] Traffic signal phase optimization is one of the key contents of signal optimization and is a bridge connecting the traffic organization channelization design and signal timing optimization at intersections. Phase optimization needs to determine issues such as which phases there are, which phases will be released simultaneously, and the number of releases. By dividing reasonable phases, phase optimization can reduce the conflicts of vehicle flows in different directions at intersections and improve the traffic efficiency at the same time. The key is to control the number of phases well. The number of phases determines traffic safety and traffic efficiency. The more phases there are, the smaller the conflicts, but the phase lost time will also increase, and vice versa.

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

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

[0005] To achieve the above object, the present invention is realized through the following technical solutions:

[0006] A signal lamp control method for step-by-step generation of a stage structure phase scheme includes the following steps:

[0007] S1. Construct a bottom-layer phase generation method, including a motor vehicle phase generation method and a pedestrian phase generation method. Considering the lane group setting and the lamp group setting, generate the motor vehicle phase turning information, and then determine the preferentially selected signal lamp type according to the lamp group and the motor vehicle phase turning information, and generate the motor vehicle phase combination and the pedestrian phase;

[0008] S2. Construct a middle-layer basic stage set generation method. First, add traffic flow conflict information to the traffic flow, and then generate a basic vehicle stage set through the motor vehicle phase combination, and combine the pedestrian phase with the basic vehicle stage set to generate a basic stage set;

[0009] S3. Construct a top-layer cycle stage combination scheme generation method. By combining the basic stage sets, then screening to obtain a set of feasible cycle stage combination schemes, and then using a linear programming model to solve the sum of the key flow ratios, and finally screening with the minimum sum of the key flow ratios as the target to obtain the optimal cycle stage combination scheme.

[0010] Further, the specific implementation method for constructing the motor vehicle phase generation method in step S1 includes the following steps:

[0011] S1.1. Extract the turning information contained within the motor vehicle phase;

[0012] S1.1.1. Perform turning combination according to the lane group settings: Combine the turning information contained in each lane into a turning set. Set an approach lane group to contain a first list of turning sets A. Perform a union operation on the turning sets with intersections within the first list of turning sets A to obtain the first turning information phase_bases-1;

[0013] S1.1.2. Perform turning combination according to the light group settings: Combine the turning information contained in each light group into a turning set. Set an approach light group to contain a second list of turning sets B. If the turning set in phase_bases-1 exists in the second list of turning sets B, skip it. Otherwise, determine whether the turning set in phase_bases-1 is a proper subset of the second list of turning sets B. If so, add the superset in the second list of turning sets B to phase_base-1, and perform a union operation on the turning sets with intersections within phase_base-1 to obtain the second turning information phase_bases-2;

[0014] S1.1.3. Detect whether there is a separately released U-turn set {'U'} and a separately released left-turn set {'L'} in phase_bases-2. If they exist, combine them into a special requirements set {'U', 'L'}. After combination, obtain the third turning information phase_base-3;

[0015] S1.2. Based on the turning information obtained in step S1.1, screen the light groups to obtain the motor vehicle phase combinations;

[0016] S1.2.1. Set the phase type classification rules for U-turns and left-turns. Then, for the U-turn protected phase and the left-turn protected phase, set the left turn of the light group in this direction to avoid being released simultaneously with the oncoming straight-ahead traffic; for the U-turn permitted phase and the left-turn permitted phase, set the light group in this direction to be released simultaneously with the oncoming straight-ahead traffic;

[0017] S1.2.2. Use all elements in the second list of turning sets B to generate a third list of turning sets C through all combinations. Screen the turning sets that conform to the third turning information phase_base-3 obtained in step S1.1 to form a list of light group turning sets light_bases;

[0018] S1.2.3. Select the best combination of lamp groups from the list of lamp group steering sets obtained in step S1.2.2 to form the motor vehicle phase; the selection method is to directly select if there is only one combination of lamp groups, and if there are multiple groups, compare them. The comparison requirement is to give priority to selecting the round cake lamp ball if there are round cake lamps ball in both this direction and the oncoming direction and the left turns in both this direction and the oncoming direction are permissive phases, otherwise give priority to selecting the arrow lamp arrow.

[0019] Furthermore, in step S1.1, the classification rule for the phase type of U-turn is set as follows: when the number of U-turn lanes ≥ 2 or the number of oncoming straight lanes ≥ 4, it is a U-turn protected phase, otherwise it is a U-turn permissive phase.

[0020] Furthermore, in step S1.1, the classification rule for the phase type of left turn is as follows:

[0021] When the number of left turn lanes ≥ 2 or the number of oncoming straight lanes ≥ 4 or the driving speed of oncoming straight vehicles ≥ 72 km / h or when the number of oncoming straight lanes is equal to 1, the left turn flow × the oncoming straight flow ≥ 50000 pcu / h or when the number of oncoming straight lanes is equal to 2 or 3, the left turn flow × the oncoming straight flow ≥ 100000 pcu / h, it is a left turn protected phase;

[0022] When the above rules are not met or the left turn flow ≤ 60 pcu / h or when the number of oncoming straight lanes is equal to 1, the left turn flow × the oncoming straight flow < 50000 pcu / h or when the number of oncoming straight lanes is equal to 2 or 3, the left turn flow × the oncoming straight flow < 100000 pcu / h, it is a left turn permissive phase.

[0023] Furthermore, step S1 also includes a method for generating pedestrian phases. Set a pedestrian phase for each pedestrian lamp. If there is a second crossing, distinguish whether the pedestrian lamp is at the approach lane or the departure lane according to the direction of the traffic flow and the order of passing through the signal lamp to obtain the pedestrian phase.

[0024] Furthermore, the specific implementation method of step S2 includes the following steps:

[0025] S2.1. Add traffic flow conflict information to the traffic flow;

[0026] S2.1.1. Input the basic traffic flow conflict table;

[0027] S2.1.2. Starting from the U-turn and left turn signal lamp types, judge that if there is a traffic flow that is a U-turn protected phase or a left turn protected phase, then add traffic flow conflict information to this traffic flow and the oncoming straight traffic flow;

[0028] S2.1.3. Starting from the lamp group setting, if there is a left-turn or U-turn arrow lamp, add traffic flow conflict information to this traffic flow and the oncoming straight traffic flow;

[0029] S2.1.4. Starting from the lane setting, if there is a straight 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 oncoming straight traffic flow;

[0030] S2.2. Generate a basic vehicle phase set through motor vehicle phase combinations;

[0031] S2.2.1. Set that the motor vehicle phase combination does not include the right-turn dedicated arrow lamp phase, and generate a potential phase set - 1 for the motor vehicle phase combination;

[0032] S2.2.2. Judge whether there are conflicts among all traffic flows included in the potential phase set - 1. If there are conflicts, delete the conflicting traffic flows to obtain the potential phase set - 2;

[0033] S2.2.3. Screen the phases in the potential phase set - 2, and delete the phase subsets in the phases existing in the potential phase set - 2 to form the potential phase set - 3;

[0034] S2.2.4. Add a right-turn dedicated arrow lamp to the potential phase set - 3, and the right-turn phase is released simultaneously with the phase in this direction to form the basic vehicle phase set;

[0035] S2.3. After the judgment based on the pedestrian phase, combine the pedestrian phase with the basic vehicle phase set to generate the basic phase set;

[0036] S2.3.1. Judge whether there is a pedestrian independent phase. If there is, bind all pedestrian phases and no longer release the pedestrian phase in other phases. Otherwise, continue to judge the parent phase and corrected phase of the pedestrian phase. When there is a parent phase of the pedestrian phase and no corrected phase of the pedestrian phase, release the pedestrian phase;

[0037] S2.3.2. Combine the basic vehicle phase set with the pedestrian phase to obtain the basic phase set.

[0038] Furthermore, the judgment method of the pedestrian independent phase in step S2.3.1 is as follows:

[0039] If the total pedestrian flow ≥ 3000 ped / h or the pedestrian flow of at least 3 branches ≥ 800 ped / h or the pedestrian flow of at least two directions of diagonal crossing ≥ 800 ped / h or there is a pedestrian flow that cannot follow the motor vehicle, set the pedestrian independent phase;

[0040] Otherwise, pedestrians are released simultaneously with the straight-through motor vehicles in the same import direction.

[0041] Further, the method for judging the mother phase and the correction phase of the pedestrian phase in step S2.3.1 is as follows:

[0042] For the one-way crossing pedestrian phase, the mother phase of the pedestrian phase is set as the straight-through motor vehicle phase in the clockwise vertical direction;

[0043] For the two-way crossing pedestrian phase, the mother phase of the pedestrian phase at the import lane is set as the phases of all motor vehicles in the oncoming and vertical directions, and the correction phase of the pedestrian phase is the phases of all motor vehicles in this direction;

[0044] For the two-way crossing pedestrian phase, the mother phase of the pedestrian phase at the export lane is set as the phases of all other motor vehicles, and the correction phase of the pedestrian phase is the phases of the motor vehicles including the oncoming straight-through motor vehicles and the motor vehicles passing through this export lane and using arrow lights.

[0045] Further, the specific implementation method of step S3 includes the following steps:

[0046] S3.1. Combine through the basic phase set, set the number of general phases to 2 to (number of forks + 2), generate the potential cycle phase combination scheme -1, where the number of forks is the number of branch forks at the intersection, equivalent to the number of branches at the intersection;

[0047] S3.2. In the potential cycle phase combination scheme -1, for each phase, based on the mother phase of the pedestrian phase and the correction phase of the pedestrian phase, select the pedestrian phase to join the phase, and generate the potential cycle phase combination scheme -2; then judge whether all motor vehicle phases and pedestrian phases are covered in the potential cycle phase combination scheme -2, and obtain the set of feasible cycle phase combination schemes after screening;

[0048] S3.3. For the set of feasible cycle phase combination schemes, solve the sum of the critical flow ratios through the linear programming model, and then select the optimal cycle phase combination scheme with the minimum sum of the critical flow ratios as the goal.

[0049] Further, the specific implementation method of step S3.3 includes the following steps:

[0050] S3.3.1. Set the objective function as the minimum sum of the critical flow ratios, and the expression is:

[0051] ;

[0052] Among them, is the critical lane group flow ratio of the i th phase, n is the number of cycle phases;

[0053] 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. The expression is:

[0054] ;

[0055] where, is the flow ratio of traffic flow k, is the stage set of traffic flow k.

[0056] Advantages of the present invention:

[0057] The signal lamp control method for step-by-step generation of a stage structure phase scheme according to the present invention provides a complete, clear, and implementable method for step-by-step generation of a stage structure phase scheme, whereby the phase scheme generation can be automated, avoiding the complete dependence on manual experience for design.

[0058] The signal lamp control method for step-by-step generation of a stage structure phase scheme according to the present invention proposes a convenient and efficient calculation model for the flow ratio of the key flow direction. The phase generation result can not only avoid traffic flow conflicts but also maximize the utilization of the green light time, improving the traffic efficiency of the intersection. Description of the drawings

[0059] Figure 1 is a flow chart of the signal lamp control method for step-by-step generation of a stage structure phase scheme according to the present invention. Specific embodiments

[0060] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to 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 a part of the embodiments of the present invention, rather than all of the specific embodiments. Usually, the components of the specific embodiments of the present invention described and shown in the accompanying drawings herein can be arranged and designed in various different configurations, and the present invention can also have other embodiments.

[0061] Therefore, the detailed description of the specific embodiments of the present invention provided in the accompanying drawings below is not intended to limit the scope of the claimed present invention, but only represents the selected specific embodiments of the present invention. All other specific embodiments obtained by those skilled in the art based on the specific embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0062] To further understand the content, features, and effects of the present invention, the following specific embodiments are exemplified and described in detail in conjunction with the attached Figure 1 as follows:

[0063] Embodiment 1:

[0064] A signal lamp control method for step - by - step generation of a stage - structure phase scheme, comprising the following steps:

[0065] S1. Construct a basic phase generation method, including a motor vehicle phase generation method and a pedestrian phase generation method. Considering the lane group setting and the lamp group setting, generate the motor vehicle phase steering information, and then determine the preferentially selected signal lamp type according to the lamp group and the motor vehicle phase steering information, and generate the motor vehicle phase combination and the pedestrian phase;

[0066] Further, the specific implementation method for constructing the motor vehicle phase generation method in step S1 includes the following steps:

[0067] S1.1. Extract the steering information included in the motor vehicle phase;

[0068] S1.1.1. Perform steering merging according to the lane group setting: Merge the steering information included in each lane into a steering set. Set an approach lane group to include a first steering set list A, and perform a union operation on the steering sets with intersections in the first steering set list A to obtain the first steering information phase_bases - 1;

[0069] S1.1.2. Perform steering merging according to the lamp group setting: Set the steering information included in each lamp group to be merged into a steering set. Set an approach lane lamp group to include a second steering set list B. If the steering set in phase_bases - 1 exists in the second steering set list B, skip it; otherwise, determine whether the steering set in phase_bases - 1 is a proper subset of the second steering set list B. If so, add the parent set in the second steering set list B to phase_base - 1, and perform a union operation on the steering sets with intersections in phase_base - 1 to obtain the second steering information phase_bases - 2;

[0070] S1.1.3. Detect whether there is a separately released U - turn set {'U'} and a separately released left - turn set {'L'} in phase_bases - 2. If so, merge them into a special requirement set {'U', 'L'}, and after merging, obtain the third steering information phase_base - 3;

[0071] Further, the phase type classification rule for setting U - turn in step S1.1 is that when the number of U - turn lanes ≥ 2 or the number of oncoming straight - through lanes ≥ 4, it is a U - turn protected phase, otherwise it is a U - turn permitted phase;

[0072] Further, the phase type classification rule for setting left - turn in step S1.1 is:

[0073] When the number of left-turn lanes ≥ 2, or the number of oncoming straight lanes ≥ 4, or the driving speed of oncoming straight vehicles ≥ 72 km / h, or when the number of oncoming straight lanes is equal to 1, the left-turn flow × the oncoming straight flow ≥ 50,000 pcu / h, or when the number of oncoming straight lanes is equal to 2 or 3, the left-turn flow × the oncoming straight flow ≥ 100,000 pcu / h, it is a left-turn protected phase;

[0074] When the above rules are not met, or the left-turn flow ≤ 60 pcu / h, or when the number of oncoming straight lanes is equal to 1, the left-turn flow × the oncoming straight flow < 50,000 pcu / h, or when the number of oncoming straight lanes is equal to 2 or 3, the left-turn flow × the oncoming straight flow < 100,000 pcu / h, it is a left-turn permitted phase;

[0075] S1.2. Based on the turning information obtained in step S1.1, screen the light groups to obtain the motor vehicle phase combinations;

[0076] S1.2.1. Set the phase type classification rules for U-turn and left-turn. Then, for the U-turn protected phase and the left-turn protected phase, set that the left-turn of the light group in this direction is avoided from being released simultaneously with the oncoming straight; for the U-turn permitted phase and the left-turn permitted phase, set that the light group in this direction is released simultaneously with the oncoming straight;

[0077] S1.2.2. Use all elements in the second turning set list B to generate a full combination to form the third turning set list C, and screen the turning sets in the third turning information phase_base-3 obtained in step S1.1 to form the light group turning set list light_bases;

[0078] S1.2.3. Select the best light group combination from the light group turning set list obtained in step S1.2.2 as the motor vehicle phase; the selection method is that if there is only one light group combination, it is directly selected. If there are multiple groups, a comparison is made. The comparison requirement is that if there are round lights ball in both this direction and the oncoming direction and the left-turns in both this direction and the oncoming direction are permitted phases, the round lights ball is preferred. Otherwise, the arrow lights arrow are preferred;

[0079] Furthermore, the method for generating the pedestrian phase is also included in step S1. Set a pedestrian phase for each pedestrian light. If there is a second crossing, distinguish whether the pedestrian light is at the approach lane or the departure lane according to the direction of the traffic flow and the order of passing through the signal lights to obtain the pedestrian phase;

[0080] Furthermore, the phases in step S1 are divided into two categories: vehicle flow phases and pedestrian phases. The phase determines which traffic flows can be released simultaneously by controlling the light groups. The generation of the phase needs to meet the following requirements:

[0081] Only those with exactly the same time right-of-way for traffic flows in the same direction can form a phase;

[0082] Judge whether the right-of-way of motor vehicle traffic flows in the same direction is exactly the same according to the lane group and signal group settings. The time right-of-way of all turning traffic flows included in the same lane should be the same; if a signal group only supports the simultaneous release of some turning traffic flows, their time right-of-way should be the same; in addition, there are also some special cases, such as some traffic flows being suitable for simultaneous release and being placed in one phase;

[0083] A phase controls traffic flows by controlling signal groups. Motor vehicle signal groups are divided into two categories: round lights (ball type) and turning arrow lights (arrow type). There are different signal group combinations for the directions of the same group of turning traffic flows. The selection of signal groups should not only consider the release relationship of traffic flows in this direction, but also consider the release relationship between traffic flows in this direction and those in the oncoming direction;

[0084] Each signal group for pedestrians constitutes a phase. Pedestrian crossing is divided into one-time crossing and two-time crossing. One-time crossing corresponds to one signal group, and two-time crossing corresponds to two signal groups;

[0085] The set of phases must cover all traffic flows.

[0086] S2. Method for generating the basic phase set in the middle layer. First, add traffic flow conflict information to the traffic flows, then generate the basic vehicle phase set through motor vehicle phase combination, and combine the pedestrian phase with the basic vehicle phase set to generate the basic phase set;

[0087] Furthermore, the specific implementation method of step S2 includes the following steps:

[0088] S2.1. Add traffic flow conflict information to the traffic flows;

[0089] S2.1.1. Input the basic traffic flow conflict table;

[0090] S2.1.2. Starting from the types of U-turn and left-turn signal lights, judge that if there is a traffic flow with a U-turn protected phase or a left-turn protected phase, add traffic flow conflict information to this traffic flow and the oncoming straight traffic flow;

[0091] S2.1.3. Starting from the signal group settings, judge that if there is an arrow light for left turn or U-turn, add traffic flow conflict information to this traffic flow and the oncoming straight traffic flow;

[0092] S2.1.4. Starting from the lane settings, judge that if there is a straight lane to the left of the U-turn lane, add traffic flow conflict information to the U-turn traffic flow in this direction and the oncoming straight traffic flow;

[0093] S2.2. Generate a set of basic vehicle phases through motor vehicle phase combinations;

[0094] S2.2.1. Set the motor vehicle phase combination not to include the right-turn dedicated arrow light phase, and generate a potential phase set - 1 for the motor vehicle phase combination;

[0095] S2.2.2. Determine whether there are conflicts between all traffic flows included in the potential phase set - 1. If there are conflicts, delete the conflicting traffic flows to obtain the potential phase set - 2;

[0096] S2.2.3. Screen the phases in the potential phase set - 2, and delete the phase subsets in the phases existing in the potential phase set - 2 to form the potential phase set - 3;

[0097] S2.2.4. Add a right-turn dedicated arrow light to the potential phase set - 3, and the right-turn phase is released simultaneously with the phase in this direction to form a set of basic vehicle phases;

[0098] S2.3. After the judgment based on the pedestrian phase, combine the pedestrian phase with the set of basic vehicle phases to generate a set of basic phases;

[0099] S2.3.1. Determine whether there is a pedestrian independent phase. If there is, bind all pedestrian phases and no pedestrian phases are released in other phases. Otherwise, continue to judge the parent phase and correction phase of the pedestrian phase. When there is a parent phase of the pedestrian phase and no correction phase of the pedestrian phase, release the pedestrian phase;

[0100] Furthermore, the judgment method for the pedestrian independent phase in step S2.3.1 is as follows:

[0101] If the total pedestrian flow ≥ 3000 ped / h or the pedestrian flow of at least 3 branches ≥ 800 ped / h or the pedestrian flow of at least two directions of diagonal crossing ≥ 800 ped / h or there is a pedestrian flow that cannot follow the motor vehicle, set the pedestrian independent phase;

[0102] Otherwise, the pedestrians follow the straight motor vehicle in the same import direction and are released simultaneously;

[0103] Furthermore, the judgment method for the parent phase and correction phase of the pedestrian phase in step S2.3.1 is as follows:

[0104] For the one-way crossing pedestrian phase, set the parent phase of the pedestrian phase as the straight motor vehicle phase in the clockwise vertical direction;

[0105] For the two-way crossing pedestrian phase, set the parent phase of the import lane pedestrian phase as all motor vehicle phases in the opposite and vertical directions, and the correction phase of the pedestrian phase as all motor vehicle phases in this direction;

[0106] For the mother phase of the pedestrian phase set at the exit lane for the secondary crosswalk, the mother phase is all other motor vehicle phases, and the corrected phase of the pedestrian phase is the motor vehicle phase including oncoming straight traffic and the motor vehicle phase passing through this exit lane and using arrow lights;

[0107] S2.3.2. Combine the basic vehicle phase set with the pedestrian phase to obtain the basic phase set;

[0108] Furthermore, a phase is a combination of a motor vehicle phase and a pedestrian phase, and there should be no conflicts in the traffic flows released in a basic phase. The generation of a basic phase needs to meet the following requirements:

[0109] There should be no conflicts in the traffic flows released within the basic phase;

[0110] The basic phase should contain as many non-conflicting traffic flows as possible to make more full use of the green light time.

[0111] S3. Construct a method for generating the top-level cycle phase combination scheme. By combining the basic phase set, then screening to obtain the set of feasible cycle phase combination schemes, and then using the linear programming model to solve the sum of the key flow ratios, and finally screening with the minimum sum of the key flow ratios as the goal to obtain the optimal cycle phase combination scheme.

[0112] Furthermore, the specific implementation method of step S3 includes the following steps:

[0113] S3.1. Combine through the basic phase set, set the number of general phases to 2 to (number of forks + 2), and generate the potential cycle phase combination scheme -1. The number of forks is the number of branch forks at the intersection, which is equivalent to the number of branches at the intersection;

[0114] S3.2. In the potential cycle phase combination scheme -1, for each phase, based on the mother phase of the pedestrian phase and the corrected phase of the pedestrian phase, select the pedestrian phase to be added to the phase to generate the potential cycle phase combination scheme -2; then determine whether all motor vehicle phases and pedestrian phases are covered in the potential cycle phase combination scheme -2, and obtain the set of feasible cycle phase combination schemes after screening;

[0115] S3.3. For the set of feasible cycle phase combination schemes, solve the sum of the key flow ratios through the linear programming model, and then select the optimal cycle phase combination scheme with the minimum sum of the key flow ratios as the goal.

[0116] Furthermore, the specific implementation method of step S3.3 includes the following steps:

[0117] S3.3.1. Set the objective function to the minimum sum of the key flow ratios, and the expression is:

[0118] ;

[0119] Among them, is the flow ratio of the key lane group in the i th stage, n is the number of cycle stages;

[0120] 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. The expression is:

[0121] ;

[0122] Among them, is the flow ratio of traffic flow k, is the stage set of traffic flow k.

[0123] Furthermore, the cycle stage plan is formed by screening the basic stage set. There may be multiple sets of cycle stage plans, and the optimal plan needs to be determined through comparison and selection. The generation of the cycle stage plan needs to meet the following requirements:

[0124] All phases within the cycle must be released at least once;

[0125] Select the optimal cycle stage combination plan with the minimum sum of the flow ratios of the key lane groups as the goal.

[0126] The technical key points and points to be protected in the present invention are:

[0127] 1. The logical steps of a complete method for generating a phase plan of the stage structure, including: the underlying phase generation method, the middle-level basic stage generation method, and the top-level cycle stage plan generation method.

[0128] 2. The solution steps of three methods (the underlying phase generation method, the middle-level basic stage generation method, and the top-level cycle stage plan generation method) and the technical methods clearly defined in the key steps of the methods.

[0129] 3. The linear programming model of the sum of the flow ratios of the key flow directions.

[0130] The abbreviations and definitions of key terms in the present invention are:

[0131] Time right of way: A vehicle obtains the time right of way when it gets a green light at an intersection, and the vehicle can pass through the intersection during this period.

[0132] Stage structure: That is, a signal cycle plan is divided into multiple stages according to the time right of way of each traffic flow.

[0133] ball-type lamp: A round cake lamp. When the round cake lamp is green, all traffic flows in that direction obtain the time right of way.

[0134] Arrow-shaped lights: Steering arrow lights, including U-turn arrow lights, left-turn arrow lights, straight-ahead arrow lights, and right-turn arrow lights. When the arrow light is green, the corresponding steering traffic flow has absolute right of way, and no other conflicting traffic flows are allowed to proceed simultaneously.

[0135] Phase (signal phase): One or several traffic flows having the same right of way in terms of time within a traffic signal cycle is called a signal phase.

[0136] Stage: Composed of one or several phases, within which the time right of way of all traffic flows remains unchanged.

[0137] Cycle stage plan: The stage plan included within one signal cycle.

[0138] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0139] Although the present application has been described above with reference to specific embodiments, various improvements can be made thereto and components can 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 can be combined with each other in any way, and the cases of these combinations are not exhaustively described in this specification only for the sake of saving space and 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 stage structure phase scheme, characterized in that, It includes the following steps: S1. Construct the underlying phase generation method, including the motor vehicle phase generation method and the pedestrian phase generation method. Considering the lane group setting and the light group setting, generate the motor vehicle phase steering information. Then, according to the light group and the motor vehicle phase steering information, determine the preferred signal light type, and generate the motor vehicle phase combination and the pedestrian phase; S2. Construct the middle-level basic phase set generation method. First, add traffic flow conflict information to the traffic flow. Then, generate the basic vehicle phase set through the motor vehicle phase combination, and combine the pedestrian phase with the basic vehicle phase set to generate the basic phase set; S3. Construct the top-level cycle phase combination scheme generation method. By combining the basic phase sets, then screening to obtain the set of feasible cycle phase combination schemes. Then, use the linear programming model to solve the sum of the critical flow ratios of the key flow directions. Finally, select the optimal cycle phase combination scheme with the minimum sum of the critical flow ratios of the key flow directions as the goal; The specific implementation method of step S3 includes the following steps: S3.

1. Combine through the basic phase sets, set the number of general phases to 2 to (the number of branches + 2), and generate the potential cycle phase combination scheme -1. The number of branches is the number of branch channels of the intersection, which is equivalent to the number of branches of the intersection; S3.

2. In the potential cycle phase combination scheme -1, for each phase, based on the mother phase of the pedestrian phase and the corrected phase of the pedestrian phase, select the pedestrian phase to join the phase to generate the potential cycle phase combination scheme -2. Then, determine whether all the motor vehicle phases and pedestrian phases are covered in the potential cycle phase combination scheme -2, and obtain the set of feasible cycle phase combination schemes after screening; S3.

3. For the set of feasible cycle phase combination schemes, solve the sum of the critical flow ratios of the key flow directions through the linear programming model, and then select the optimal cycle phase combination scheme with the minimum sum of the critical flow ratios of the key flow directions as the goal; The specific implementation method of step S3.3 includes the following steps: S3.3.

1. Set the objective function as the minimum sum of the critical flow ratios of the key flow directions, and the expression is: where x i is the critical lane group flow ratio in the i-th stage, and n is the number of cycle stages; S3.3.

2. Set the constraint condition as that the critical flow ratio of each phase should be greater than the flow ratio of each traffic flow, and the expression is: Among them, tf k is the flow ratio of traffic flow k, and W k is the set of phases of traffic flow k.

2. The signal lamp control method generated step by step according to the stage structure phase scheme described in 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. Extract the steering information included in the motor vehicle phase; S1.1.

1. Conduct steering merging according to the lane group setting: Merge the steering information included in each lane into a steering set. Set an approach lane group to include the first steering set list A, and perform the union operation on the steering sets with intersections in the first steering set list A to obtain the first steering information phase_bases - 1; S1.1.

2. Perform turning combination according to the lamp group settings: Combine the turning information included in each lamp group into a turning set. Set that an approach lane lamp group includes a second turning set list B. If the turning set in phase_bases - 1 exists in the second turning set list B, skip it; otherwise, determine whether the turning set in phase_bases - 1 is a proper subset of the second turning set list B. If so, add the superset in the second turning set list B to phase_base - 1, and perform a union operation on the turning sets with intersections in phase_base - 1 to obtain the second turning information phase_bases - 2; S1.1.

3. Detect whether there is a separately released U - turn set {'U'} and a separately released left - turn set {'L'} in phase_bases - 2. If they exist, merge them into a special requirement set {'U', 'L'}. After merging, obtain the third turning information phase_base - 3; S1.

2. Based on the turning information obtained in step S1.1, screen the lamp groups to obtain the motor vehicle phase combinations; S1.2.

1. Set the phase type classification rules for U - turn and left - turn. Then, for the U - turn protected phase and the left - turn protected phase, set that the left - turn of the lamp group in this direction is avoided from being released simultaneously with the oncoming straight - through traffic; for the U - turn permitted phase and the left - turn permitted phase, set that the lamp group in this direction is released simultaneously with the oncoming straight - through traffic; S1.2.

2. Use all elements in the second turning set list B to generate a third turning set list C through full combination, and screen the turning sets that meet the third turning information phase_base - 3 obtained in step S1.1 to form a lamp group turning set list light_bases; S1.2.

3. Select the best lamp group combination from the lamp group turning set list obtained in step S1.2.2 as the motor vehicle phase. The selection method is as follows: If there is only one lamp group combination, directly select it; if there are multiple groups, conduct a comparison. The comparison requirement is that if there are round - cake lights ball in both this direction and the oncoming direction and the left - turns in both this direction and the oncoming direction are permitted phases, then preferentially select the round - cake lights ball; otherwise, preferentially select the arrow lights arrow.

3. The signal lamp control method generated step by step according to the phase scheme of the stage structure described in claim 2, characterized in that, In step S1.1, the phase type classification rule for setting U - turn is that when the number of U - turn lanes ≥ 2 or the number of oncoming straight - through lanes ≥ 4, it is a U - turn protected phase; otherwise, it is a U - turn permitted phase.

4. The signal lamp control method generated step by step according to the stage structure phase scheme described in claim 3, characterized in that, In step S1.1, the phase type classification rule for setting left - turn is as follows: When the number of left - turn lanes ≥ 2 or the number of oncoming straight - through lanes ≥ 4 or the driving speed of oncoming straight - through vehicles ≥ 72 km / h or when the number of oncoming straight - through lanes is equal to 1, the left - turn flow × the oncoming straight - through flow ≥ 50000 pcu / h or when the number of oncoming straight - through lanes is equal to 2 or 3, the left - turn flow × the oncoming straight - through flow ≥ 100000 pcu / h, it is a left - turn protected phase; When the above rules are not met, or when the left-turn flow rate ≤ 60 pcu / h, or when the number of oncoming straight lanes = 1, left-turn flow rate × oncoming straight flow rate < 50000 pcu / h, or when the number of oncoming straight lanes = 2 or 3, left-turn flow rate × oncoming straight flow rate< 100000 pcu / h, it is a left-turn permitted phase.

5. The signal lamp control method generated step by step according to the stage structure phase scheme described in claim 4, characterized in that, The generation method of the pedestrian phase is also included in step S1. A pedestrian phase is set for each pedestrian light. If there is a second crossing, the traffic flow direction and the order of passing through the signal lights are used to distinguish whether the pedestrian light is on the approach lane or the departure lane, and the pedestrian phase is obtained.

6. The signal lamp control method generated step by step according to the phase scheme of the stage structure described in 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. Starting from the types of U-turn and left-turn signal lights, judge that if there is a traffic flow with a U-turn protected phase or a left-turn protected phase, add traffic flow conflict information to this traffic flow and the oncoming straight traffic flow; S2.1.

3. Starting from the lamp group setting, judge that if there is a left-turn or U-turn arrow lamp, add traffic flow conflict information to this traffic flow and the oncoming straight traffic flow; S2.1.

4. Starting from the lane setting, judge that if there is a straight 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 oncoming straight traffic flow; S2.

2. Generate a basic vehicle phase set through the combination of motor vehicle phases; S2.2.

1. Set that the motor vehicle phase combination does not include the right-turn dedicated arrow lamp phase, and generate a potential phase set - 1 for the motor vehicle phase combination; S2.2.

2. Judge whether there are conflicts between all traffic flows included in the potential phase set - 1. If there are conflicts, delete the conflicting traffic flows to obtain the potential phase set - 2; S2.2.

3. Screen the phases in the potential phase set - 2, and delete the phase subsets in the phases existing in the potential phase set - 2 to form the potential phase set - 3; S2.2.

4. Add a right-turn dedicated arrow lamp to the potential phase set - 3, and the right-turn phase is released simultaneously with the phase in this direction to form the basic vehicle phase set; S2.

3. After the judgment of the pedestrian phase, combine the pedestrian phase with the basic vehicle phase set to generate the basic phase set; S2.3.

1. Judge whether there is a pedestrian independent phase. If there is, bind all pedestrian phases and no pedestrian phase is released in other phases. Otherwise, continue to judge the mother phase and correction phase of the pedestrian phase. When there is a mother phase of the pedestrian phase and no correction phase of the pedestrian phase, 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 lamp control method generated step by step according to the phase scheme of the stage structure as claimed in claim 6, characterized in that, The judgment method of the pedestrian independent phase in step S2.3.1 is: If the total pedestrian flow ≥ 3000 ped / h or the pedestrian flow of at least 3 branches ≥ 800 ped / h or the pedestrian flow of at least two directions of diagonal crossing ≥ 800 ped / h or there is a pedestrian flow that cannot follow the motor vehicle, set the pedestrian independent phase; Otherwise, the pedestrians follow the straight motor vehicle in the same approach direction and are released simultaneously.

8. A signal lamp control method generated step by step according to the stage structure phase scheme as claimed in claim 7, characterized in that, The judgment method of the mother phase and correction phase of the pedestrian phase in step S2.3.1 is: For the one-time crossing pedestrian phase, set the mother phase of the pedestrian phase as the straight motor vehicle phase in the clockwise vertical direction; For the import lane pedestrian phase of the secondary crosswalk pedestrian phase setting, the mother phase of the pedestrian phase is all motor vehicle phases in the oncoming and perpendicular directions, and the corrected phase of the pedestrian phase is all motor vehicle phases in this direction; For the export lane pedestrian phase of the secondary crosswalk pedestrian phase setting, the mother phase of the pedestrian phase is all other motor vehicle phases, and the corrected phase of the pedestrian phase is the motor vehicle phase including oncoming straight traffic, and the motor vehicle phase passing through this export lane and using arrow lights.

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