Signalized intersection control device and method with waiting area under colored Petri net

Abstract

The present invention relates to the technical field of traffic signal control, and specifically to a control device and method for a signalized intersection with a waiting area under a colored Petri net. Define an intersection; construct a modular model of the intersection path according to the definition of the intersection; construct a modular model of intersection path signal control according to the definition of the intersection, including a path signal control model without a waiting area and a path signal control model with a waiting area; construct a Petri net model of the intersection by combining the modular models of the path to establish a control model for the signalized intersection. The model constructed by the present invention can flexibly switch the signal lights of the waiting area and the non-waiting area, and is suitable for various types of intersections with and without waiting areas, and can reduce or even avoid traffic accidents caused by drivers being unable to respond in time due to signal light switching.

Description

Technical Field

[0001] The invention relates to the technical field of traffic signal control, and in particular to a control device and method for a signal intersection containing a waiting area under a colored Petri net. Background Art

[0002] Many traffic accidents occur near intersections. These traffic accidents occur because the driver does not react to the change of the signal light in time, or because the signal light status changes after the vehicle enters the intersection, and the vehicles on the conflicting path enter the intersection and collide, or because the vehicles in the waiting area block the vehicles entering the intersection. In order to minimize or even avoid the occurrence of such traffic accidents, a more optimized control algorithm is needed to optimize the intersection signal lights, so that the signal lights of the intersection with the waiting area can be better coordinated and switched more flexibly to be suitable for various types of intersections. The present invention establishes a control device and method, which can flexibly control the signal lights in the waiting area, so as to solve the signal control problem of the intersection and the signal conflict problem of the intersection with the waiting area. Summary of the invention

[0003] In order to solve the technical problem that it is difficult to establish signal control for all types in the prior art, the purpose of the present invention is to provide a signal intersection control device and method containing a waiting area under a colored Petri net, and the technical solution adopted is as follows:

[0004] In a first aspect, an embodiment of the present invention provides a control device for a signalized intersection with a waiting area under a colored Petri net, the control device comprising the following modules:

[0005] Initial definition module, used to define intersections;

[0006] A vehicle representation module is used to determine the position of a vehicle counter according to the definition of the intersection; different colored tokens are used to represent different vehicle types;

[0007] A first modular model building module is used to build a modular model of the intersection path according to the definition of the intersection;

[0008] A second modular model building module is used to build a modular model of intersection path signal control according to the definition of the intersection, including a path signal control model without a waiting area and a path signal control model with a waiting area;

[0009] The control model building module is used to build a Petri net model of the intersection by combining the intersection path and the modular model of the intersection path signal control, and establish a control model of the intersection.

[0010] In a possible implementation, defining an intersection includes:

[0011] Differentiate the entrance roads:

[0012] First, they are distinguished by path. When lanes at different entrances have the same path, they are classified as the same entrance road.

[0013] Then, according to the lane distinction, when different paths share the same entrance road, the entrance roads shared by different paths belong to the same entrance road;

[0014] The path without waiting area is divided into the entrance road to the intersection , the non-changeable lane immediately following the entrance road , the path through the intersection followed by the immutable lane , respectively , and describe Enter The front part, entering But didn't enter Parts and entry part of;

[0015] The path to be traveled is divided into the entrance road to the intersection , the non-changeable lane immediately following the entrance road , the waiting area immediately following the non-changeable lane , followed by the path where the waiting area will leave the intersection , respectively , , and describe Enter The front part, entering But didn't enter part, enter But didn't enter Parts and entry part.

[0016] In a possible implementation, determining the position of the vehicle counter according to the definition of the intersection includes:

[0017] A first vehicle counter is placed on the entrance road of the intersection, wherein the distance between the vehicle counter and the intersection is not less than the distance that a vehicle passes within one green light duration when traveling at a free speed, and not greater than the distance that a vehicle passes within two green light durations;

[0018] A second vehicle counter is provided at the entrance of each non-changeable lane close to the intersection;

[0019] A third vehicle counter is respectively set at the exit of each path entering the intersection; wherein the exit of the intersection is the entrance of the waiting area;

[0020] A fourth vehicle counter is respectively set at the exit of each path from the intersection;

[0021] A fifth vehicle counter is respectively arranged at the exit of each path from the waiting area.

[0022] In a possible implementation, the tokens of different colors are used to represent different vehicle models, including:

[0023] The upstream counter of each entrance road corresponds to a transition separately. The transition is provided with a unique library to represent the vehicle model, which is connected by a bidirectional directed arc. The library representing the vehicle model has the same number of tokens as the number of vehicle models, and the number and color of the tokens in the library remain unchanged. The color of each token represents a vehicle model.

[0024] In a possible implementation, the modular model of the intersection path includes:

[0025] A Petri net model is constructed for all the paths of the intersection, and a modular model of each path is constructed; for a path with a waiting area, the modular model corresponding to the part entering the intersection exit includes a model of the waiting area and a modular model assuming that the waiting area does not exist.

[0026] In a possible implementation, the construction of a modular model for intersection path signal control includes:

[0027] In the first signal control model, vehicles passing through the intersection are controlled by a set of signals. Two places are used to represent the red light state and the green light state respectively, and two transitions are used to represent the signal switching from red light to green light and from green light to red light respectively.

[0028] The second signal control model, based on the first signal control model, adds two more places to represent the green light state of the entry and exit zone signal lights and the red light state of the entry and exit zone signal lights. The red light state of the entry and exit zone signal lights is shared with the place representing the red light state in the first signal control model. Two transitions are added to represent the signal switching of the entry and exit zone signal lights from red to green and from green to red.

[0029] Select one of the two signal control models in the same phase, add a Petri net structure represented by or consisting of a library place and two transitions, and connect the two transitions to the library place representing the green light in the first signal control model and the library place representing the waiting area signal light in the second signal control model through directed arcs; at the same time, add another library place to ensure that the phase can select one of the signal control models instead of the other signal control model.

[0030] In a possible implementation, the Petri net model of the intersection is constructed by combining the intersection path and the modular model of the intersection path signal control, and the control model of the intersection is established, including:

[0031] For each path at the intersection, all modular models belonging to the path are connected from top to bottom through directed arcs according to the driving direction of the vehicles on the current path.

[0032] In a possible implementation, the method further includes:

[0033] Based on the Petri net model of the intersection, a signal control model capable of eliminating conflicts is constructed according to path conflicts;

[0034] The path conflicts include: 1. conflicts between the path in the green light state and other paths in the current phase;

[0035] 2. If a path in the green light state in the next phase has a waiting area, there is a conflict between the waiting area and the path in the green light state in the current phase;

[0036] 3. If there are multiple paths with waiting areas in the next phase, there will be conflicts between the waiting areas of these paths.

[0037] In a possible implementation, constructing a signal control model capable of eliminating conflicts includes:

[0038] Connect the red light state of the path to the transition of the conflicting path to the green light through a directed arc to ensure that the path that conflicts with the current path cannot turn on the green light at the same time to eliminate the first conflict;

[0039] If there is a conflicting path with a waiting area on the current path, the library indicating the red light state of the current path is connected to the conflicting path through a directed arc to switch the signal of entering the waiting area to the green light transition, so as to ensure that when the current path is in the green light state, if the waiting area of ​​the conflicting path prevents the vehicles of the current path from passing through the intersection, the green light controlling the vehicles to enter the waiting area cannot be turned on at the same time, so as to eliminate the second conflict;

[0040] If there is a conflict between the current path with a waiting area and other paths with waiting areas, the third conflict is eliminated by connecting the red light of the two paths as if the path has no waiting area and the transition of the green light of the waiting area in the other path.

[0041] In a second aspect, a method for controlling a signalized intersection with a waiting area under a colored Petri net is provided, the method comprising the following steps:

[0042] Define intersections;

[0043] According to the definition of the intersection, the position of the vehicle counter is determined; different colored tokens are used to represent different vehicle types;

[0044] According to the definition of the intersection, a modular model of the intersection path is constructed;

[0045] According to the definition of the intersection, a modular model of intersection path signal control is constructed, including a path signal control model without a waiting area and a path signal control model with a waiting area;

[0046] By combining the modular models of intersection paths and intersection path signal control, a Petri net model of the intersection is constructed, and a control model of the intersection is established.

[0047] In a possible implementation, the path signal control model must always satisfy:

[0048] 1. Each path represents the state of the traffic light in the library, one of which has a token and the other does not have a token;

[0049] 2. Among the places where the paths represent the traffic light states of the same group of signals, one of them has a token, and for each path in the green light state, all conflicting paths of the path have tokens in the places representing the red light state;

[0050] 3. When the traffic light of the current path changes from red to green, all paths that conflict with the current path have tokens in the red light state corresponding to the library; after the traffic light of the current path changes to green, these tokens will be locked in the above-mentioned library indicating the red light state until the traffic lights of all conflicting paths switch to red;

[0051] 4. At the beginning of phase N, it is required that phase N+1 is known. When the green light of phase N is turned on, if the paths with waiting areas in phase N+1 conflict with the paths in phase N, then these paths are controlled as paths without waiting areas; if the paths with waiting areas in phase N+1 do not conflict with the paths in phase N, then the green lights for entering the waiting areas are turned on when the phase N light is green, and the signals for these paths to exit the waiting areas are red in phase N and green in phase N+1. At the same time, the waiting areas of these paths cannot conflict with any of the paths, otherwise they are controlled as paths without waiting areas.

[0052] The embodiments of the present invention have at least the following beneficial effects:

[0053] Refining the entrance roads of intersections can more completely express the details of traffic demand and make the traffic model modular.

[0054] By using colored Petri nets to establish a basic framework, different car models can be distinguished well, so as to provide optimization solutions for different car models.

[0055] The intersection is modeled modularly, and a complete intersection model is constructed by combining modular models. It has strong universality and is applicable to various types of intersections with and without waiting areas.

[0056] The model includes the simulation of the traffic lights in the waiting area and the non-waiting area, and can flexibly switch the traffic lights in the waiting area and the non-waiting area.

[0057] The model includes the simulation of various path conflicts in all directions of the intersection and in the waiting and non-waiting areas, which can reduce or even avoid traffic accidents caused by drivers' inability to respond in time due to traffic light switching.

[0058] For the road intersection signal model that meets the requirements of the present invention, there are no other restrictions except for the restrictions on the signal combination of conflicting paths, and the timing scheme has the largest adjustable space, thereby improving the traffic capacity of the intersection. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 A schematic diagram of a module of a signalized intersection control device including a waiting area under a colored Petri net provided by an embodiment of the present invention;

[0061] Figure 2 A schematic diagram of the position of a vehicle counter provided by an embodiment of the present invention;

[0062] Figure 3 A schematic diagram of a Petri net model without a waiting area provided by an embodiment of the present invention;

[0063] Figure 4 A schematic diagram of a Petri net model with a path in a waiting area provided by an embodiment of the present invention;

[0064] Figure 5 A schematic diagram of an intersection provided by an embodiment of the present invention, in which there are no shared lanes in each direction of the intersection, but the left-turn lanes are all provided with waiting areas;

[0065] Figure 6 A partial schematic diagram of a signalized intersection control device including a waiting area under a colored Petri net provided by an embodiment of the present invention;

[0066] Figure 7 A flowchart of a method for controlling a signalized intersection with a waiting area under a colored Petri net provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following, in combination with the accompanying drawings and preferred embodiments, a signal intersection control device and method containing a waiting area under a colored Petri net proposed by the present invention, its specific implementation method, structure, characteristics and effects are described in detail as follows.

[0068] In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0069] Among them, in the description of the embodiments of the present invention, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a way to describe the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" refers to two or more than two.

[0070] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0071] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0072] The embodiments of the present invention are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present invention are also applicable to similar technical problems.

[0073] The specific scheme of the signalized intersection control device and method with a waiting area under a colored Petri net provided by the present invention is described in detail below in conjunction with the accompanying drawings.

[0074] Embodiment 1:

[0075] See also Figure 1 , which shows a module schematic diagram of a signal intersection control device containing a waiting area under a colored Petri net provided in Example 1, and the following modules of the model:

[0076] The initial definition module 10 is used to define the intersection.

[0077] First distinguish the entrance roads:

[0078] First, the lanes are divided according to the paths. When the lanes at different entrances have the same paths, the lanes at different entrances are classified as the same entrance road.

[0079] Then, according to the lane distinction, when different paths share the same entrance road, the entrance roads shared by different paths belong to the same entrance road;

[0080] The path without waiting area is divided into the entrance road to the intersection , the non-changeable lane immediately following the entrance road , the path through the intersection followed by the immutable lane , respectively , and describe Enter The front part, entering But didn't enter Parts and entry part of;

[0081] The path to be traveled is divided into the entrance road to the intersection , the non-changeable lane immediately following the entrance road , the waiting area immediately following the non-changeable lane , followed by the path where the waiting area will leave the intersection , respectively , , and describe Enter The front part, entering But didn't enter part, enter But didn't enter Parts and entry part.

[0082] According to the usual intersection road layout, the entrance road to the intersection and its collection , Each immutable lane entering the intersection at the lower end and its collection , the non-changeable lane immediately following the intersection on a path without a waiting area The path through the intersection and its collection , a path with a waiting area is followed by an immutable lane Waiting area and its collection , followed by The path through the intersection and its collection , where vehicles with different turns are already in the lanes of the corresponding paths; entrance roads , , respectively , express Enter The front part, entering But not entering the intersection exit; if the path does not have a waiting area, the path entering the intersection exit starts from the path that passes through the intersection. ,use Indicates entry If the path has a waiting area, the path entering the intersection starts from the waiting area. and ,use and Respectively indicate immediately after Enter Parts and entry part.

[0083] The vehicle representation module 20 is used to determine the position of the vehicle counter according to the definition of the intersection; different colored tokens are used to represent different vehicle models.

[0084] The vehicle counter is mainly used to detect whether the vehicle has reached the next part of its path. Figure 2 , Figure 2 This is a schematic diagram of the vehicle counter location. Figure 2 Among them, Counter1, Counter2, Counter3, Counter4 and Counter5 represent the set vehicle counters.

[0085] The entrance road to the intersection has a large distance to the first vehicle counter Counter1, the distance between the vehicle counter and the intersection is not less than the distance that the vehicle passes within one green light duration when driving at free speed, and not greater than the distance that the vehicle passes within two green light durations;

[0086] A second vehicle counter Counter2 is set at the entrance of each immutable lane close to the intersection;

[0087] A third vehicle counter Counter3 is set at each exit of each path entering the intersection; wherein the exit of the intersection is the entrance of the waiting area;

[0088] A fourth vehicle counter Counter4 is respectively set at the exit of each path from the intersection;

[0089] A fifth vehicle counter Counter5 is respectively set at the exit of each path from the waiting area.

[0090] The upstream counter of each entry road corresponds to a transition , the transition has a dedicated library Represents the vehicle model, through a bidirectional directed arc and transition Connected; indicates the location of the vehicle model There are the same number of tokens as the number of car models, and the number and color of tokens in the library remain unchanged. The color of each token represents a car model.

[0091] The first modular model building module 30 is used to build a modular model of the intersection path according to the definition of the intersection.

[0092] A Petri net model is constructed for all the paths of the intersection, and a modular model of each path is constructed; for a path with a waiting area, the modular model corresponding to the part entering the intersection exit includes a model of the waiting area and a modular model assuming that the waiting area does not exist.

[0093] The second modular model building module 40 is used to build a modular model of intersection path signal control according to the definition of the intersection, including a path signal control model without a waiting area and a path signal control model with a waiting area.

[0094] For paths without waiting areas, there is a unique signal control model for control. Vehicles passing through intersections are controlled by a set of signals, and a modular model including path signal control is constructed. For paths with waiting areas, there are two signal control models at the same time. The first one is to treat the path with the waiting area as the path without the waiting area, and vehicles passing through the intersection are controlled by a set of signals. The second one is that vehicles entering and exiting the waiting area are controlled by two sets of signals respectively, and a modular model of signal control including the above two mechanisms is constructed.

[0095] Specifically, a path signal control model without a waiting area is constructed:

[0096] Using two libraries and Respectively represent the red light state and the green light state, using two transitions and Represent the signal switching from red to green and from green to red, and connect the library representing the green light state to the transition entering the intersection exit superior.

[0097] Specifically, a path signal control model with a waiting area is constructed, and the model includes two modular models of signal control:

[0098] In the first signal control model, vehicles passing through the intersection are controlled by a set of signals and two libraries are used. and Respectively represent the red light state and the green light state, using two transitions and Respectively represent the signal switching of red light switching to green light and green light switching to red light;

[0099] In the second signal control model, vehicles entering and exiting the waiting area are controlled by two sets of signals, one set of signals controls vehicles entering the waiting area, and the other set of signals controls vehicles leaving the waiting area and passing through the intersection.

[0100] The second signal control model adds two more libraries based on the first signal control model. and They represent the green light state of the signal light in the waiting area and the state of the signal light in the exit waiting area respectively. The red light state of the signal light in the waiting area is shared with the library representing the red light state in the first mechanism. Two transitions are added They respectively indicate the signal switching of the traffic light in the waiting area from red to green and from green to red.

[0101] Two signal control models select one of them in the same phase and add a library and two changes , The Petri net structure is composed of or, and the two transitions are connected to the library representing the green light in the first mechanism through directed arcs. and the second mechanism indicates the location of the waiting area signal light On the other hand, we define the directed arc ; At the same time, add another library To ensure that the phase can select one of the signal control models without triggering another signal control model, define a directed arc , , and .

[0102] The control model building module 50 is used to build a Petri net model of the intersection by combining the intersection path and the modular model of the intersection path signal control, and establish a control model of the intersection.

[0103] See also Figure 3 , Figure 3 This is a schematic diagram of the Petri net model without a waiting area; please refer to Figure 4 , Figure 4 It is a schematic diagram of a Petri net model with a path in the waiting area.

[0104] Connect all modular models on the same path, including modular models of all intersection paths on the path and modular models of intersection path signal control.

[0105] According to the direction of vehicle travel, the modular model of the intersection path is connected from top to bottom with unidirectional directed arcs to the transition representing the exit; in the first signal control model, each path through the intersection There is a corresponding change ; In the second signal control model, each waiting area There is a corresponding change , the path through the intersection There is a corresponding change .

[0106] The evolution of two signal models and Connect to the same library At the same time, the library Connect to Up, Change The triggering indicates that the vehicle in the path leaves the intersection.

[0107] Indicates the green light status of the library , and The corresponding changes , and Connected with bidirectional directed arcs.

[0108] It should be noted that the Petri net model of the intersection through this path can simulate the driving process of vehicles through the intersection:

[0109] When a vehicle enters each path, except for the number and type of tokens in the library representing the vehicle model, the vehicle counters arranged on the path will trigger the corresponding transitions of the vehicle counters in turn according to the direction of its travel. The transitions will transfer the tokens colored by the vehicle model in the corresponding library in the direction of the directed arc.

[0110] For each , each time the counter at the most upstream counts a car of a certain model, Is triggered once, Add a token with the color of the car model, and The number of tokens in and their types remain unchanged.

[0111] When the lane at the bottom of w cannot be changed The counter at the entrance counts each time a car of a certain model enters. , Is triggered once, The number of tokens with the color of the model decreases by one, and The number of tokens with the color of the vehicle type increases by one; whenever a vehicle of a certain type moves from a non-changeable lane Enter the path or waiting area hour, Decrease the model's token by one, and or Add a token of the model; a car of a certain model moves from the waiting area Enter the path hour, Decrease the model's token by one, and Add a token corresponding to the model;

[0112] When a vehicle of a certain model When leaving, is triggered, causing Subtract a token with the model as the color.

[0113] In some embodiments, based on the Petri net model of the intersection, a signal control model capable of eliminating conflicts is constructed according to path conflicts, and the path conflicts include:

[0114] 1. Conflict between the path in the green light state in the current phase and other paths;

[0115] 2. If a path in the green light state in the next phase has a waiting area, there is a conflict between the waiting area and the path in the green light state in the current phase;

[0116] 3. If there are multiple paths with waiting areas in the next phase, there will be conflicts between the waiting areas of these paths.

[0117] Based on the Petri net model of the intersection, a signal control model capable of eliminating conflicts is constructed according to the path conflicts, including:

[0118] The library in the red light state of the path is connected to the transition of its conflicting path switching to the green light through a directed arc to ensure that the path that conflicts with the current path cannot turn on the green light at the same time, thereby eliminating the first conflict.

[0119] In some embodiments, each Conflicting Paths The restriction that the green lights cannot be on at the same time, that is, the definition of directed arcs and .

[0120] If there is a conflicting path with a waiting area on the current path, the library indicating the red light state of the current path is connected to the conflicting path through a directed arc, and the signal for entering the waiting area is switched to the green light transition to ensure that when the current path is in the green light state, if the waiting area of ​​the conflicting path hinders the vehicles on the current path from passing through the intersection, the green light controlling the vehicles to enter the waiting area cannot be turned on at the same time, thereby eliminating the second conflict.

[0121] In some embodiments, each Conflicting Path Waiting Area The restriction that the green lights cannot be on at the same time, that is, the definition of directed arcs and .

[0122] If there is a conflict between the current path with a waiting area and other paths with waiting areas, the third conflict is eliminated by connecting the red light of the two paths as if the path has no waiting area and the transition of the green light of the waiting area in the other path.

[0123] Add a path with a waiting area. If there is a conflict between the waiting areas and the paths with the same waiting areas, the green lights cannot be turned on at the same time. That is, define a directed arc. and .

[0124] Embodiment 2:

[0125] See also Figure 7 , Figure 7 A flowchart of a method for controlling a signalized intersection with a waiting area under a colored Petri net provided in Example 2, the method comprising:

[0126] Step S1, defining an intersection;

[0127] Step S2, determining the position of the vehicle counter according to the definition of the intersection; using tokens of different colors to represent different vehicle types;

[0128] Step S3, constructing a modular model of the intersection path according to the definition of the intersection;

[0129] Step S4, constructing a modular model of intersection path signal control according to the definition of the intersection, including a path signal control model without a waiting area and a path signal control model with a waiting area;

[0130] Step S5, constructing a Petri net model of the intersection by combining the intersection path and the modular model of the intersection path signal control, and establishing a control model of the intersection.

[0131] In some embodiments, the control method for a signalized intersection with a waiting area under a colored Petri net requires that, during the entire control process, the path signal control model must satisfy the following conditions:

[0132] 1. When the path represents the traffic light state, one of the places has a token and the other does not;

[0133] 2. Among the places where the paths represent the traffic light states of the same group of signals, one of them has a token, and for each path in the green light state, all conflicting paths of the path have tokens in the places representing the red light state;

[0134] 3. When the traffic light of the current path changes from red to green, all paths that conflict with the path have tokens in the storage places indicating the red light state; after the traffic light of the current path changes to green, these tokens will be locked in the above storage places indicating the red light state until the traffic lights of all conflicting paths switch to red;

[0135] 4. At the beginning of phase N, it is required that phase N+1 is known. When the green light of phase N is turned on, if the paths with waiting areas in phase N+1 conflict with the paths in phase N, then these paths are controlled as paths without waiting areas; if the paths with waiting areas in phase N+1 do not conflict with the paths in phase N, then the green lights for entering the waiting areas are turned on when the phase N light is green, and the signals for these paths to exit the waiting areas are red in phase N and green in phase N+1. At the same time, the waiting areas of these paths cannot conflict with any of the paths, otherwise they are controlled as paths without waiting areas.

[0136] In some embodiments, a two-way six-lane road intersection is used as an example for explanation, assuming that there are no shared lanes in each direction of the intersection, but the left-turn lanes are all provided with waiting areas.

[0137] See also Figure 5 As shown, Figure 5 This is a schematic diagram of an intersection where there are no shared lanes in all directions, but the left-turn lanes are all equipped with waiting areas; among them, wl is the left-turn lane of the westbound entrance road; ws is the straight lane of the westbound entrance road; wr is the right-turn lane of the westbound entrance road; nl is the left-turn lane of the northbound entrance road; ns is the straight lane of the northbound entrance road; nr is the right-turn lane of the northbound entrance road; el is the left-turn lane of the eastbound entrance road; es is the straight lane of the eastbound entrance road; er is the right-turn lane of the eastbound entrance road; sl is the left-turn lane of the southbound entrance road; ss is the straight lane of the southbound entrance road; sr is the right-turn lane of the southbound entrance road.

[0138] See also Figure 6 , Figure 6 A partial schematic diagram of the control model of a signalized intersection based on colored Petri nets.

[0139] To distinguish the entrance road and path direction of the intersection, Figure 6 The places and transitions in the model are distinguished by adding \_xy after the names used in the above model construction, where x = w,n,e,s represents the four entrances of west, north, east and south, and y = l,s,r represents left turn, straight ahead and right turn.

[0140] Figure 6 The paths that conflict with the left-turn paths of the middle and west entrances are the left turn and straight-ahead of the north entrance, the straight-ahead of the east entrance, and the left turn of the south entrance; Figure 6 The paths that conflict with the straight paths of the middle and west entrances are the straight path of the north entrance, the left turn of the east entrance, and the left turn and straight path of the south entrance. Figure 6 The paths that conflict with the left-turn path of the north entrance are the left turn and straight-ahead of the east entrance, the straight-ahead of the south entrance, and the left turn of the west entrance; Figure 6 The paths that conflict with the straight path of the north entrance are the straight path of the east entrance, the left turn of the south entrance, and the left turn and straight path of the west entrance; Figure 6 The paths that conflict with the left-turn path of the east entrance are the left turn and straight-ahead of the south entrance, the straight-ahead of the west entrance, and the left turn of the north entrance; Figure 6 The paths that conflict with the straight path of the east entrance are the straight path of the south entrance, the left turn of the west entrance, and the left turn and straight path of the north entrance; Figure 6 The paths that conflict with the left-turn path of the south entrance are the left turn and straight-ahead of the west entrance, the straight-ahead of the north entrance, and the left turn of the east entrance; Figure 6 The paths that conflict with the straight path of the south entrance are the straight path of the west entrance, the left turn of the north entrance, and the left turn and straight path of the east entrance.

[0141] It should be noted that the path with the waiting area needs to lock the change of the signal controlling the waiting area with the red light library of the path.

[0142] Specifically, taking the green light for the left turn at the west entrance of the intersection as an example, in order to avoid conflicts, the traffic light of the conflicting path of the left turn path at the west entrance cannot be green.

[0143] Assume that the N+1 phase is obtained according to the traffic volume forecast, in which the left-turn path wl at the west entrance is green. Then when the waiting area of ​​path wl has no conflict with the path with green light in phase N, and the waiting area of ​​wl does not conflict with the waiting area of ​​the path in phase N+1, the green light for wl to enter the waiting area is turned on in phase N; if the waiting area of ​​path wl has no conflict with the path with green light in phase N, but the waiting area of ​​wl conflicts with the waiting area of ​​the path in phase N+1, the green light for wl to enter the waiting area is turned on in phase N, and all the paths with waiting areas that conflict with wl are controlled as paths without waiting areas. As mentioned above, it is assumed that the control mechanism of path wl is the second type, that is, it is controlled by two sets of signals for entering and exiting the waiting area.

[0144] When the green light of phase N is turned on, the green light of wl entering the waiting area is turned on at the same time. The library Green\_wl(w,d,z) has a token. The vehicle enters the waiting area (w,d,z) from (w,d). When the token moves to Choose\_wl(w,d,p), because the signal for entering the waiting area is green and the signal for exiting the waiting area is red, the other mechanism will not be triggered at this time. After entering the waiting area, the vehicle waits for the signal for exiting the waiting area to turn green before passing through the intersection.

[0145] At the end of phase N, the path of phase N turns red. At this time, there is a token in the red light warehouse of the path that conflicts with path wl. After the wl transition is enabled, there is a token in the green light warehouse of the exit waiting area. The exit waiting area signal turns on the green light and the vehicle passes through the intersection.

[0146] The embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. There may be other divisions in actual implementation. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection of devices or units through some interfaces, which may be electrical, mechanical or other forms.

[0147] It should also be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0148] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0149] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0150] The above contents are only specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A signalized intersection control device with a waiting area under a colored Petri net, characterized in that: The control device includes the following modules: Initial definition module, used to define intersections; A vehicle representation module, for determining a vehicle counter position according to a definition of the intersection; Different colored tokens are used to represent different vehicle types; wherein, according to the definition of the intersection, the position of the vehicle counter is determined, including: a first vehicle counter is placed on the entrance road of the intersection, the distance between the vehicle counter and the intersection is not less than the distance that the vehicle passes within one green light duration when traveling at a free speed, and not greater than the distance that the vehicle passes within two green light durations; a second vehicle counter is set at the entrance of each immutable lane close to the intersection; a third vehicle counter is set at the exit of each path entering the intersection; wherein the exit of the intersection is the entrance to the waiting area; a fourth vehicle counter is set at the exit of each path leaving the intersection; a fifth vehicle counter is set at the exit of each path leaving the waiting area; When a vehicle is traveling on each path, except for the number and type of tokens in the library representing the vehicle model, the vehicle counters arranged on the path will trigger the corresponding transitions of the vehicle counters in turn according to the direction of the vehicle. The transitions will transfer the tokens with the color of the vehicle model in the corresponding library in the direction of the directed arc. A first modular model building module is used to build a modular model of the intersection path according to the definition of the intersection; A second modular model building module is used to build a modular model of intersection path signal control according to the definition of the intersection, including a path signal control model without a waiting area and a path signal control model with a waiting area; The control model building module is used to build a Petri net model of the intersection by combining the modular model of the intersection path and the intersection path signal control, and to establish a control model of the intersection that can eliminate the conflict based on the path conflict.

2. The signalized intersection control device with waiting area under colored Petri net according to claim 1 is characterized in that: The intersection definition includes: Differentiate the entrance roads: First, they are distinguished by path. When lanes at different entrances have the same path, they are classified as the same entrance road. Then, according to the lane distinction, when different paths share the same entrance road, the entrance roads shared by different paths belong to the same entrance road; The path without waiting area is divided into the entrance road to the intersection , the non-changeable lane immediately following the entrance road , the path through the intersection followed by the immutable lane , respectively , and describe Enter The front part, entering But didn't enter Parts and entry part of; The path to be traveled is divided into the entrance road to the intersection , the non-changeable lane immediately following the entrance road , the waiting area immediately following the non-changeable lane , followed by the path where the waiting area will leave the intersection , respectively , , and describe Enter The front part, entering But didn't enter part, enter But didn't enter Parts and entry part.

3. The signalized intersection control device with waiting area under colored Petri net according to claim 1 is characterized in that: The tokens of different colors are used to represent different models, including: In the modular model of each entrance road, the most upstream counter corresponds to a transition alone. The transition is equipped with a unique library to represent the vehicle type, which is connected by a bidirectional directed arc. The library representing the vehicle type has the same number of tokens as the number of vehicle types, and the number and color of the tokens in the library remain unchanged. The color of each token represents a vehicle type.

4. The signalized intersection control device with waiting area under colored Petri net according to claim 1 is characterized in that: The modular model of the intersection path includes: A Petri net model is constructed for all the paths of the intersection, and a modular model of each path is constructed; for a path with a waiting area, the modular model corresponding to the part entering the intersection exit includes a model of the waiting area and a modular model assuming that the waiting area does not exist.

5. The signalized intersection control device with waiting area under colored Petri net according to claim 3 is characterized in that: The modular model for constructing intersection path signal control includes: In the first signal control model, vehicles passing through the intersection are controlled by a set of signals. Two places are used to represent the red light state and the green light state respectively, and two transitions are used to represent the signal switching from red light to green light and from green light to red light respectively. The second signal control model, based on the first signal control model, adds two more places to represent the green light state of the entry and exit zone signal lights and the red light state of the entry and exit zone signal lights. The red light state of the entry and exit zone signal lights is shared with the place representing the red light state in the first signal control model. Two transitions are added to represent the signal switching of the entry and exit zone signal lights from red to green and from green to red. Select one of the two signal control models in the same phase, add a Petri net structure represented by or consisting of a library place and two transitions, and connect the two transitions to the library place representing the green light in the first signal control model and the library place representing the waiting area signal light in the second signal control model through directed arcs; at the same time, add another library place to ensure that the phase can select one of the signal control models instead of the other signal control model.

6. The signalized intersection control device with waiting area under colored Petri net according to claim 1 is characterized in that: The method of constructing a Petri net model of the intersection and establishing a control model of the intersection by combining the intersection path and the modular model of the intersection path signal control includes: For each path at the intersection, all modular models belonging to the path are connected from top to bottom through directed arcs according to the driving direction of the vehicles on the current path.

7. The signalized intersection control device with waiting area under colored Petri net according to claim 1 is characterized in that: Also includes: Based on the Petri net model of the intersection, a signal control model capable of eliminating conflicts is constructed according to path conflicts; The path conflicts include:

1. conflicts between the path in the green light state and other paths in the current phase; 2. If a path in the green light state in the next phase has a waiting area, there is a conflict between the waiting area and the path in the green light state in the current phase; 3. If there are multiple paths with waiting areas in the next phase, there will be conflicts between the waiting areas of these paths.

8. The signalized intersection control device with waiting area under colored Petri net according to claim 6 is characterized in that: The signal control model capable of eliminating conflicts is constructed, including: Connect the red light state of the path to the transition of the conflicting path to the green light through a directed arc to ensure that the path that conflicts with the current path cannot turn on the green light at the same time to eliminate the first conflict; If there is a conflicting path with a waiting area on the current path, the library indicating the red light state of the current path is connected to the conflicting path through a directed arc to switch the signal of entering the waiting area to the green light transition, so as to ensure that when the current path is in the green light state, if the waiting area of ​​the conflicting path prevents the vehicles of the current path from passing through the intersection, the green light controlling the vehicles to enter the waiting area cannot be turned on at the same time, so as to eliminate the second conflict; If there is a conflict between the current path with a waiting area and other paths with waiting areas, the third conflict is eliminated by connecting the red light of the two paths as if the path has no waiting area and the transition of the green light of the waiting area in the other path.

9. A control method for a signalized intersection with a waiting area under a colored Petri net, characterized in that: The method comprises the following steps: Define intersections; According to the definition of the intersection, the position of the vehicle counter is determined; tokens of different colors are used to represent different vehicle types; wherein, according to the definition of the intersection, the position of the vehicle counter is determined, including: a first vehicle counter is placed on the entrance road of the intersection, the distance between the vehicle counter and the intersection is not less than the distance that the vehicle passes within one green light duration when traveling at a free speed, and not more than the distance that the vehicle passes within two green light durations; a second vehicle counter is set at the entrance of each immutable lane close to the intersection; a third vehicle counter is set at the exit of each path entering the intersection; wherein the exit of the intersection is the entrance to the waiting area; a fourth vehicle counter is set at the exit of each path leaving the intersection; a fifth vehicle counter is set at the exit of each path leaving the waiting area; When a vehicle is traveling on each path, except for the number and type of tokens in the library representing the vehicle model, the vehicle counters arranged on the path will trigger the corresponding transitions of the vehicle counters in turn according to the direction of the vehicle. The transitions will transfer the tokens with the color of the vehicle model in the corresponding library in the direction of the directed arc. According to the definition of the intersection, a modular model of the intersection path is constructed; According to the definition of the intersection, a modular model of intersection path signal control is constructed, including a path signal control model without a waiting area and a path signal control model with a waiting area; By combining the modular models of intersection paths and intersection path signal control, a Petri net model of the intersection is constructed. Based on the path conflicts, a control model of the intersection that can eliminate conflicts is established.

10. The method for controlling a signalized intersection with a waiting area under a colored Petri net according to claim 9, characterized in that: The path signal control model must always satisfy:

1. Each path represents the state of the traffic light in the library, one of which has a token and the other does not have a token; 2. Among the places where the paths represent the traffic light states of the same group of signals, one of them has a token, and for each path in the green light state, all conflicting paths of the path have tokens in the places representing the red light state; 3. When the traffic light of the current path changes from red to green, all paths that conflict with the current path have tokens in the storage places indicating the red light state; When the traffic light of the current path turns green, these tokens will be locked in the above-mentioned library indicating the red light state until the traffic lights of all conflicting paths turn red; 4. At the beginning of phase N, it is required that phase N+1 is known. When the green light of phase N is turned on, if the paths with waiting areas in phase N+1 conflict with the paths in phase N, then these paths are controlled as paths without waiting areas; if the paths with waiting areas in phase N+1 do not conflict with the paths in phase N, then the green lights for entering the waiting areas are turned on when the phase N light is green, and the signals for these paths to exit the waiting areas are red in phase N and green in phase N+1. At the same time, the waiting areas of these paths cannot conflict with any of the paths, otherwise they are controlled as paths without waiting areas.

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