A networked traffic signal light controller and an intelligent control method for traffic signal lights with emergency vehicle priority

Abstract

The present invention discloses a networked traffic signal light controller and an intelligent control method for traffic signal lights with priority for emergency vehicles. The networked traffic signal light controller is used to execute an intelligent control method for traffic signal lights with priority for emergency vehicles. The method makes full use of traffic density information of ordinary vehicles and networked emergency vehicle information to realize ordinary vehicle scheduling and multi-priority emergency vehicle scheduling, and solves the task of vehicle scheduling at traffic intersections. In the traffic scenario where emergency vehicles of multiple priorities appear on the road and emergency vehicles enter at the same time in multiple phases, the present invention realizes the timing scheduling and control of the signal lights of networked emergency vehicles and ordinary vehicles, can accurately handle the problem of priority passage of emergency vehicles, and enable emergency vehicles to quickly pass through the intersection while ensuring safety. At the same time, the efficiency of vehicles passing through the intersection is improved, proving the practicality of a networked traffic signal light controller and an intelligent control method for traffic signal lights with priority for emergency vehicles.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent transportation, and in particular relates to a networked traffic signal light controller and an intelligent control method for a traffic signal light with emergency vehicle priority. Background Art

[0002] With the continuous development of urbanization and the continuous improvement of people's living standards, the cost of traffic congestion is getting higher and higher, and the pressure on urban traffic is increasing. Traffic congestion, especially the congestion caused by emergency vehicles, has become an important aspect of urban governance and the protection of people's lives and property. One way to reduce traffic congestion is to intelligently control the phase of traffic lights according to the current traffic density on the road to dispatch vehicles and ensure priority passage for emergency vehicles as much as possible.

[0003] In related technologies, most traffic lights are still controlled by pre-set fixed time, without real-time observation of vehicle information on the road, nor can they sense emergency vehicles, and cannot dynamically and adaptively update scheduling strategies according to real-time traffic. A few traffic lights have realized an intersection emergency vehicle priority system built through wireless communication technology, which effectively alleviates the problem of emergency vehicle congestion. For example, in the document "Design of Intelligent Networked Intersection Signal Control System Based on V2X, Lu Tao, Computer Technology and Development, 2021", an intelligent networked intersection signal control system is designed based on the V2X network, which can realize accurate perception and control of intersection traffic elements. The system consists of four parts: human-computer interaction, vehicle-mounted terminal, roadside terminal and signal control. Vehicles exchange position, speed, acceleration and other information through the V2X network. The roadside equipment sends the phase, timing and other information of the traffic light to the vehicle through the V2X network, realizing advanced assisted driving applications such as green wave speed guidance, emergency vehicle priority and left turn assistance, which can effectively improve the efficiency of intersection traffic and reduce the incidence of traffic accidents.

[0004] However, the above research is a theoretical model proposed under the scenario that all vehicles on the road are equipped with V2X communication modules. It does not cross-integrate the intelligent timing scheduling of traffic lights for emergency vehicles in the Internet of Vehicles and ordinary vehicles, and does not consider the real-time road conditions. It cannot guarantee the safety and efficiency of emergency vehicles and ordinary vehicles when they cross each other. Summary of the invention

[0005] In order to overcome the deficiencies in the prior art, the present invention provides a networked traffic light controller and an intelligent control method for traffic lights with priority for emergency vehicles. The method is applied to the networked traffic light controller NTLC (Networked Traffic Light Controller), fully utilizing the road vehicle image information to monitor the road conditions in real time, and obtaining the density of each traffic flow and ordinary vehicle traffic in each phase; fully utilizing the networked emergency vehicle information and traffic density information received through wireless communication interaction to calculate the weight, and then performing the timing scheduling and control of the networked emergency vehicle and ordinary vehicle traffic lights, and finally realizing the intelligent control of traffic lights with priority for emergency vehicles, overcoming the defect of the existing method that it is not possible to refer to the real-time road conditions and simultaneously schedule emergency vehicles and ordinary vehicles, and at the same time, through the information reservation mechanism, accurately handling the problem of priority passage of emergency vehicles, so that emergency vehicles can quickly pass through the intersection while ensuring safety, and at the same time improving the efficiency of vehicles passing through the intersection.

[0006] In order to make the content of the present invention clearer, the concepts of traffic flow and phase are first explained:

[0007] Traffic flow: The flow of vehicles arriving in the same direction and forming the same queue on one or more lanes is defined as traffic flow tf i (0≤i≤N-1, N≤3n);

[0008] Where i is the number of the traffic flow in the intersection, n is a positive integer representing the number of traffic flows coming from the intersection, and each traffic flow has at most three directions: right turn, straight, and left turn. Therefore, there are at most 3n traffic flows at each intersection. When i = 3m, it means tf i is a right-turn traffic flow, when i=3m+1, it means tf i is a straight traffic flow, i = 3m + 2, indicating tf i It is a left-turning traffic flow;

[0009] For example, tf0 represents the traffic flow turning right at the first intersection, tf1 represents the traffic flow going straight at the first intersection, tf2 represents the traffic flow turning left at the first intersection, and tf3 represents the traffic flow turning right at the second intersection;

[0010] It should be noted that a traffic flow tf i There is more than one lane in the system, let the kth lane be L k , each traffic flow corresponds to a set of lanes it contains According to this definition, the traffic direction represented by the traffic flow is determined by the traffic flow subscript.

[0011] Phase: Define the set of all signal lights as signal light group D pAt the same time, the light group has two states, red and green, and the phase P j Is a state of a signal light group, represented by:

[0012]

[0013] Where 0≤j≤M, M represents the number of phases, P j,绿灯 Indicates that in phase P j Traffic light in medium green state, P j,红灯 The signal light is in red state;

[0014] It should be noted that P j,绿灯 There will be no conflict between the released traffic flows, and each phase corresponds to a set of released traffic flows.

[0015] Define the initial phase P 初始 When the system is activated, all lanes at the intersection are closed to traffic. 初始 It is expressed as:

[0016]

[0017] In order to make the content of the invention more clearly described, it is also necessary to briefly explain the concepts of traffic flow weight, phase weight, traffic flow urgency weight and phase urgency:

[0018] Traffic flow weight: Traffic flow weight It corresponds to the congestion degree of traffic flow in this direction and is a real number greater than 0. The larger its value is, the higher the congestion degree of the traffic flow and the higher the urgency. Conversely, the lower the congestion degree of the traffic flow and the lower the urgency.

[0019] Phase Weight: Phase Weight is the phase P j Medium j,绿灯 The weighted sum of the corresponding traffic flow weights is a real number greater than 0. Since one phase corresponds to multiple traffic flows, the congestion level of each traffic flow corresponding to the phase should be considered when evaluating the congestion level of the phase.

[0020] Traffic flow urgency weight: Traffic flow urgency weight is a real number greater than 0, and its value corresponds to the congestion level of connected emergency vehicles in the traffic flow in that direction.

[0021] Phase Urgency: Phase Urgency When there is a connected emergency vehicle, phase P j The weight of .

[0022] The present invention is based on each phase P in the intersection phase set j The weight of the corresponding traffic flow Phase selection and timing are performed.

[0023] In the traffic scenario of the present invention, there are two types of vehicles: ordinary vehicles and networked emergency vehicles:

[0024] Ordinary vehicles, including:

[0025] (1) Vehicles without networked communication modules installed. These vehicles account for the majority of vehicles on the road and are unable to communicate with the wireless communication module of the networked traffic light controller at the intersection. The networked traffic light controller NTLC obtains the traffic density through the camera for weight calculation;

[0026] (2) Vehicles that have installed networked communication modules but have not issued emergency vehicle reservation information. This type of vehicle accounts for a very small number of vehicles on the road. They are equipped with networked communication modules and can communicate with the wireless communication module of the networked traffic light controller at the intersection.

[0027] Networked emergency vehicles: including vehicles that are equipped with networked communication modules and issue emergency vehicle reservation information. In the traffic scenario of the present invention, it is assumed that all emergency vehicles that need to perform emergency rescue tasks are equipped with networked communication modules and can communicate with the wireless communication module in the networked traffic light controller at the intersection, and obtain priority right of way through the reservation mechanism under any circumstances.

[0028] After the networked traffic light controller NTLC executes the vehicle dispatch initialization program, it enters the vehicle dispatch program;

[0029] If there is no networked emergency vehicle on the road, the networked traffic light controller NTLC collects image information of vehicles on the road through the camera within a fixed time interval Δt, and obtains the traffic density information of ordinary vehicles on each lane and the waiting time of traffic in each direction based on the image recognition algorithm. Subsequently, the NTLC calculates the weight of each traffic flow based on the traffic density information of ordinary vehicles and the waiting time of traffic flow. Finally, according to Calculate phase weight The phase with the largest weight is selected and the timing is calculated.

[0030] During the execution of the timing plan, if the networked traffic light controller NTLC receives the networked emergency vehicle reservation information from the on-board networked communication module, it means that a networked emergency vehicle has entered the current road section and is already within the dispatch range of the intersection. At this time, the networked traffic light controller NTLC stops the current timing plan, and displays the yellow light n seconds in advance for vehicle buffering (0≤n≤3), and switches to the multi-priority emergency vehicle dispatching procedure. After the networked traffic light controller NTLC receives the networked emergency vehicle reservation information, it adds the networked emergency vehicle to the networked emergency vehicle processing queue of the corresponding phase according to the networked emergency vehicle reservation information. Then calculate the urgency of each phase And the phase with the greatest phase urgency is selected.

[0031] When an emergency vehicle passes, if the networked traffic light controller NTLC receives the networked emergency vehicle reservation information, it will add the networked emergency vehicle to the networked emergency vehicle processing queue of the corresponding phase. And continue to monitor vehicle information; if NTLC receives information about a connected emergency vehicle passing through, it removes the vehicle from the connected emergency vehicle processing queue in that phase If there are still networked emergency vehicles that need to pass in this phase, the phase will not be changed. If all networked emergency vehicles have passed in this phase, that is, If it is empty and there are still connected emergency vehicles in other phases, the phase urgency is recalculated and the phase right of way is reallocated; if all emergency vehicles on the road have passed, that is, the processing queue of all phases If both are empty, the multi-priority emergency vehicle dispatching ends and jumps to the normal vehicle dispatching.

[0032] The technical solution of the present invention is:

[0033] A networked traffic signal light controller, comprising:

[0034] A wireless communication module, used to interact with a networked communication module installed in the vehicle and receive networked emergency vehicle reservation information and passing information;

[0035] Cameras are used to monitor the traffic flow conditions in each direction in real time and collect image information of vehicles on the road;

[0036] The networked traffic light controller is used to calculate the timing plan, execute vehicle scheduling and control decisions on the status of the traffic lights.

[0037] According to the networked traffic signal light controller, a method for intelligently controlling a traffic signal light with emergency vehicle priority is implemented, comprising the following steps:

[0038] Step 1, the networked traffic signal light controller performs vehicle dispatch initialization, including normal vehicle dispatch initialization and multi-priority emergency vehicle dispatch initialization;

[0039] Step 2: If the wireless communication module does not receive the networked emergency vehicle reservation information, the networked traffic light controller performs ordinary vehicle dispatching, and the wireless communication module continues to monitor the networked emergency vehicle reservation information until the networked emergency vehicle reservation information is received. The networked traffic light controller sets the current traffic light to yellow for n seconds and executes step 3 at the same time;

[0040] Step 3, if the wireless communication module receives the networked emergency vehicle reservation information, the networked traffic light controller performs multi-priority emergency vehicle dispatch, and at the same time, the wireless communication module monitors the networked emergency vehicle reservation information and emergency vehicle passing information, until there is no networked emergency vehicle reservation information and all networked emergency vehicle passing information is received, the networked traffic light controller performs step 2;

[0041] Step 4, repeat steps 2 and 3 to implement intelligent control of traffic lights with emergency vehicle priority.

[0042] Furthermore, the vehicle scheduling initialization in step 1 specifically includes:

[0043] Normal vehicle dispatch initialization:

[0044] Initialize traffic flow tf according to the intersection shape i (0≤i≤N-1, N≤3n);

[0045] Where i is the number of the traffic flow at the intersection, n is a positive integer representing the number of traffic flows coming from the intersection, and each traffic flow has at most three directions: right turn, straight, and left turn. Therefore, each intersection has at most 3n traffic flows; a traffic flow tf i There is more than one lane in the system, let the kth lane be L k , each traffic flow corresponds to a set of lanes it contains Used to determine the traffic direction represented by the traffic flow through the traffic flow subscript;

[0046] Initialize the set of all signal lights, that is, signal light group D p , initialize all weights, including traffic flow weights Phase Weight Traffic flow urgency weight Phase Urgency And initialize its value to 0; initialize the phase of all signal light groups to P 初始 ; Initialize each phase P j , and initialize its released traffic flow set

[0047] Multi-priority emergency vehicle dispatch initialization:

[0048] Each phase corresponds to a connected emergency vehicle processing queue The queue stores data structures describing the status information of connected emergency vehicles. <id,tf i ,v id ,t id ,e id >, where id is the unique identifier of the connected emergency vehicle, tf i is the traffic flow, v id is the speed, t id is the waiting time at the intersection, e id For urgency.

[0049] Furthermore, the phase P j and the P 初始 Specifically:

[0050] The phase P j Indicates signal light group D p Status:

[0051]

[0052] Where 0≤j≤M, M is the number of phases, P j,绿灯 Indicates that in phase P j Traffic light in medium green state, P j,红灯 The signal light is in red state;

[0053] The P 初始 It is the initial phase, indicating that all lanes at the intersection are prohibited from passing when the system is started:

[0054]

[0055] Furthermore, the ordinary vehicle dispatch in step 2 specifically includes the following sub-steps:

[0056] Step 2.1, the networked traffic signal light controller obtains ordinary vehicle traffic density information based on road vehicle image information through an image recognition algorithm;

[0057] The cameras in each direction collect n consecutive frames of road vehicle image information (1≤n≤5) within a fixed time interval Δt, and extract the number of vehicles in each lane on each frame image. And obtain the waiting time of the first ordinary vehicle arriving at the intersection in each traffic flow Among them, L k represents the lane to which it belongs, and n represents the nth frame;

[0058] If the networked traffic signal light controller does not obtain the traffic density information of ordinary vehicles in the current road vehicle image, and all processing queues are empty, the traffic density information of ordinary vehicles is obtained again according to the real-time road vehicle image information;

[0059] Step 2.2: If the networked traffic signal light controller obtains ordinary vehicle traffic density information, phase weight and timing calculation are performed according to the ordinary vehicle traffic density information, including:

[0060] Traffic flow i The number of vehicles in the continuous n frames of road vehicle images is Where n is an integer greater than or equal to 1, the number of vehicles The calculation formula is expressed as:

[0061]

[0062] Then calculate the trend parameters of each traffic flow change The calculation formula is expressed as:

[0063]

[0064] Then the traffic flow tf i Weight The calculation formula is expressed as:

[0065]

[0066] Among them, u1 and u2 are weights, which are natural numbers used to adjust the influence factors of each parameter on the overall weight and also play a role in data standardization;

[0067] Among them, f is the density function, and its input is the number of vehicles in each frame The output is the traffic density of the lane;

[0068] Phase p j Weight The calculation formula is expressed as:

[0069]

[0070] The networked traffic signal light controller calculates the timing and obtains the timing plan. If there are n phases at the intersection and the i-th phase p i The weight is the largest, then P i The calculation formula of the obtained timing PT is expressed as:

[0071]

[0072] Among them, T is the maximum timing time that can be obtained for each phase and is set by the user;

[0073] Step 2.3, the networked traffic signal light controller executes the timing plan and continuously monitors the networked emergency vehicle reservation information through the wireless communication module;

[0074] If the wireless communication module does not receive the networked emergency vehicle reservation information, the networked traffic signal light controller waits for the current timing plan to end before recalculating the weights of each phase and regenerating the timing plan;

[0075] If the wireless communication module receives the reservation information of the networked emergency vehicle, the networked traffic light controller will change the current phase to yellow light n seconds in advance, and add the networked emergency vehicle that has made the reservation to the networked emergency vehicle processing queue. Then perform multi-priority emergency vehicle dispatch.

[0076] Furthermore, the multi-priority emergency vehicle dispatch in step 3 specifically includes the following sub-steps:

[0077] Step 3.1: The networked traffic light controller calculates the urgency of each phase, selects the phase with the greatest urgency, and releases the corresponding Traffic flow in

[0078] Fill in the networked emergency vehicle status information according to the networked emergency vehicle reservation information obtained by the wireless communication module <id,tf i ,v id ,t id ,e id >, calculate the traffic flow emergency weight according to the networked emergency vehicle status information If tf i There are N connected emergency vehicles, and tf i The maximum speed limit is v max , then the traffic flow tf i The calculation formula of the traffic flow emergency weight is expressed as:

[0079]

[0080] Among them, r1, r2, r3, and r4 are weights, which are all natural numbers, used to adjust the influence factors of each parameter on the overall weight, and also play the role of data standardization;

[0081] Phase P j Phase urgency The calculation formula is expressed as:

[0082]

[0083] Step 3.2, the wireless communication module continuously monitors the reservation information and passing information of the networked emergency vehicle;

[0084] If the wireless communication module receives the information that the networked emergency vehicle has passed, the networked traffic light controller deletes The corresponding vehicle information is as follows;

[0085] If all the passing information of the networked emergency vehicles in the phase is received, and there are still networked emergency vehicles in other phases, the networked traffic light controller re-executes the multi-priority emergency vehicle dispatch, otherwise it does not change the phase and waits for all the networked emergency vehicles in the phase to pass safely;

[0086] If the connected emergency vehicle processing queue corresponding to each phase When both are empty, that is, when all the networked emergency vehicles on the road have passed the intersection, the networked traffic light controller executes ordinary vehicle scheduling, otherwise, re-executes multi-priority emergency vehicle scheduling.

[0087] Furthermore, the ordinary vehicles include vehicles without an Internet-connected communication module installed, and vehicles with an Internet-connected communication module installed but without emergency vehicle reservation information issued;

[0088] The networked emergency vehicle includes a vehicle equipped with a networked communication module and sending out emergency vehicle reservation information, and the emergency vehicles have different priorities.

[0089] Compared with the prior art, the present invention has the following beneficial effects:

[0090] The present invention integrates the adaptive scheduling of ordinary vehicles and the scheduling method of networked emergency vehicles. It extracts the image information of road vehicles in real time through image recognition algorithm, monitors the traffic conditions of ordinary vehicles, and establishes an information reservation mechanism through the wireless communication module and the networked communication module installed on the emergency vehicle, so as to obtain the status information of the networked emergency vehicle in time, and then calculate the most reasonable phase allocation and signal light timing plan. While ensuring the priority passage of emergency vehicles, it also guarantees the intelligent scheduling of intersections for ordinary vehicles to the greatest extent, and minimizes the impact on the traffic efficiency of ordinary vehicles.

[0091] When performing emergency vehicle dispatch, the present invention divides the priority of emergency vehicles more finely through various evaluation parameters. In traffic scenarios where emergency vehicles of multiple priorities appear on the road and emergency vehicles enter in multiple phases at the same time, the emergency vehicle processing queue is sorted according to the priority of the emergency vehicle, thereby ensuring efficient and accurate dispatch of multiple emergency vehicles and improving the overall traffic efficiency of multiple emergency vehicles, and proving the practicability of a networked traffic signal light controller and an intelligent control method for traffic signals with priority for emergency vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 The figure is a schematic diagram of the system structure of a method for intelligently controlling a traffic light with emergency vehicle priority in an embodiment of the present invention.

[0093] Figure 2 The figure is a logic flow chart of an intelligent control method for a traffic light with emergency vehicle priority in an embodiment of the present invention. DETAILED DESCRIPTION

[0094] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail and completely in conjunction with the accompanying drawings and specific embodiments. It should be noted that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention, and the embodiments do not limit the scope of protection of the present invention.

[0095] Example

[0096] At traffic intersections, use Figure 1 The structure of the intelligent control system of the traffic light with emergency vehicle priority shown in the figure includes a networked traffic light controller NTLC equipped with a wireless communication module and a camera, a networked emergency vehicle and a normal vehicle;

[0097] There is no limitation on the types and performances of various devices, and any scheduling method of this form is within the protection scope of the present invention.

[0098] The subject of the present invention is a networked emergency vehicle and an ordinary vehicle, wherein the NTLC collects road vehicle image information through a camera, and the networked emergency vehicle needs to interact with the NTLC through a reservation mechanism. Through the image recognition algorithm, the NTLC will obtain the traffic density information of ordinary vehicles based on the collected road vehicle image information, make phase decisions based on the traffic density information of ordinary vehicles and the status information of the networked emergency vehicle, and perform intelligent timing. Among them, the image recognition algorithm and the decision algorithm are not limited.

[0099] like Figure 2 As shown, a method for intelligently controlling a traffic light with emergency vehicle priority comprises the following steps:

[0100] Step A: Vehicle dispatch initialization

[0101] A1: Normal vehicle dispatch initialization

[0102] When applying to an intersection for the first time or when the basic settings of the method need to be changed, D needs to be initialized according to the shape of the intersection. p , initialize all weights, including traffic flow weights Phase Weight Traffic flow urgency weight Phase Urgency And initialize its value to 0. All light groups are initialized to phase P 初始 Initialization phase P j , and initialize its released traffic flow set

[0103] In this step, the initialized intersection can be a crossroads, a T-junction, or any other irregularly shaped intersection with traffic lights;

[0104] The phase of the initialized intersection information light can be a common dual-phase, three-phase or any complex non-conflicting phase setting;

[0105] In order to better describe the correspondence between traffic flow and phase, the four directions of east, south, west and north are corresponded to the letters E, S, W, and N respectively. The direction from south to north is recorded as SN, the direction from east to west is recorded as EW, and so on.

[0106] In this embodiment, the intersection is an intersection with an angle of 90°, and the compatible signal group set of the intersection includes three phases P1, P2, and P3, and each traffic flow of the intersection includes two lanes. Phase P1 includes traffic flows tf1, tf0, tf4, and tf3 in four directions of EW, EN, WE, and WS; phase P2 includes traffic flows tf2 and tf5 in two directions of WN and ES; phase P3 includes traffic flows tf6, tf9, tf8, tf7, and tf8 in six directions of NS, SN, NW, NE, SW, and SE. 10 、tf 11 .

[0107] A2: Emergency vehicle dispatch initialization;

[0108] Initialize the emergency vehicle handling program, each phase corresponds to a networked emergency vehicle handling queue The queue stores data structures describing the status information of emergency vehicles <id,tf i ,v id ,t id ,e id >, the parameters are the unique identifier of the emergency vehicle, the traffic flow it belongs to, the speed, the waiting time at the intersection and the urgency.

[0109] In this step, the type of connected emergency vehicle is not limited, and it can be an ambulance, fire truck, police car or even any vehicle equipped with a connected communication module that encounters an emergency.

[0110] In this step, the method for obtaining the status information of the networked emergency vehicle is not limited. The status information can be obtained through an image recognition algorithm, or it can be obtained by the emergency vehicle sending it to the intersection information monitoring device.

[0111] For example, at the above intersection, a fire truck enters at phase P1 and a police car on routine patrol enters at phase P2. These two emergency vehicles send their respective status information to NTLC through the communication network. <id,q i ,v i ,t i ,e i >.

[0112] Step B: General vehicle dispatch

[0113] The ordinary vehicle in this embodiment may be a vehicle that is not equipped with an Internet-connected communication module or a vehicle that is equipped with an Internet-connected communication module but has not sent reservation information.

[0114] B1: Obtain the traffic density information of ordinary vehicles through image recognition algorithm. The specific acquisition method is as follows:

[0115] First, the cameras in each direction collect n = 3 frames of continuous road vehicle image information within a fixed time interval Δt = 5s. Then, NTLC extracts the number of vehicles in each lane in each frame based on the image recognition algorithm. And obtain the waiting time of the first vehicle arriving at the intersection in each traffic flow Among them, L k represents the lane to which it belongs, and n represents the nth frame, for example, N 11 Represents the number of vehicles in the first frame of image collected on lane 1.

[0116] In this step, ordinary vehicles may be trucks, vans, buses, cars, sports cars and other common vehicles on the road that are not in emergency situations.

[0117] The image recognition algorithm may be deepsort, yolov5 or other image recognition algorithms.

[0118] B2: Phase weight and timing scheme calculation;

[0119] According to the traffic density information of ordinary vehicles, a suitable weight calculation formula is selected to calculate the traffic weight of each traffic flow, and then the weight of each phase is obtained according to the phase to which each traffic flow belongs.

[0120] First, calculate the trend parameters of each traffic flow The number of vehicles in the traffic flow tends to increase or decrease, and the weight is given an increase or decrease coefficient accordingly. i The number of vehicles in the continuous n-frame image acquisition is Each traffic flow Calculated by formula (1), the traffic flow change trend parameter can be calculated by formula (2):

[0121]

[0122]

[0123] Then the traffic flow tf i Weight It can be calculated by formula (3):

[0124]

[0125] Next, P j The phase weight It can be calculated by formula (4).

[0126]

[0127] Then the phase with the largest weight is selected to grant the right of way and the timing is generated according to the weight ratio of each phase;

[0128] In this embodiment, there are currently three phases at the intersection, and their weights have been generated by the above steps, and their weights are PW1, PW2, and PW3, respectively. Among them, PW1 is the largest, that is, the current phase No. 1 is selected to give it the right of way, and the timing time PT1 obtained can be calculated by formula (5):

[0129]

[0130] Among them, T is the maximum timing time that each phase can obtain.

[0131] B3: The wireless communication module of the networked traffic light controller NTLC monitors the networked emergency vehicle reservation information;

[0132] While executing the timing plan in B2, NTLC continuously monitors the intersection information. If it does not receive the reservation information of the connected emergency vehicle, it will wait until the current timing plan is about to end, recalculate the weights of each phase, and regenerate the timing plan. If it receives the reservation information of the connected emergency vehicle, it will turn the current phase to yellow light n seconds in advance, use multi-priority emergency vehicle scheduling, and jump to step C.

[0133] Step C: Multi-priority emergency vehicle dispatch

[0134] C1: Calculate the phase urgency of each phase and select the phase with the largest phase urgency.

[0135] Fill in the connected emergency vehicle status information based on the connected emergency vehicle reservation information obtained by the wireless communication module <id,tf i ,v id ,t id,e id >, calculate the traffic flow emergency weight based on these parameter information If the traffic flow tf i There are N connected emergency vehicles, and tf i The maximum speed limit is v max , then tf i The traffic flow emergency weight can be calculated by formula (6):

[0136]

[0137] Among them, r1, r2, r3, and r4 are weights, which are natural numbers used to adjust the influence factors of each parameter on the overall weight, and also play a role in data standardization.

[0138] Next, phase P j Phase urgency It can be calculated by formula (7):

[0139]

[0140] Select the phase with the greatest phase urgency and release the corresponding Traffic flow in .

[0141] For example, in the above scenario, the urgency of the fire truck is significantly higher than that of the police car on daily patrol, so the traffic flow set in the phase where the fire truck is located is released.

[0142] C2: The wireless communication module of the networked traffic light controller NTLC monitors the reservation information and passing information of networked emergency vehicles;

[0143] When a connected emergency vehicle passes through an intersection, it needs to send a passing message to the wireless communication module of the connected traffic light controller at the intersection to notify the intersection that it has passed safely. After receiving the passing message, the NTLC deletes the corresponding passing vehicle information.

[0144] If all the networked emergency vehicles in that phase have passed safely and there are still networked emergency vehicles in other phases, repeat the multi-priority emergency vehicle dispatch; otherwise, do not change the phase and wait for all the networked emergency vehicles in that phase to pass safely.

[0145] If the connected emergency vehicle processing queues corresponding to each phase are empty, that is, all connected emergency vehicles on the road have passed the intersection, it will be transferred to ordinary vehicle dispatch, otherwise, multiple priority emergency vehicle dispatch will be repeated.

[0146] Step D: Repeat steps B and C until the system crashes.

[0147] This article uses specific examples to illustrate the principles and implementation schemes of the present invention. The above is only a common example of the present invention, which is used to help understand the method and core ideas of the present invention, and is not used to limit the present invention. At the same time, for those of ordinary skill in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent control method for a traffic light with emergency vehicle priority, implemented by a networked traffic light controller, characterized in that: The networked traffic signal light controller comprises: A wireless communication module, used to interact with a networked communication module installed in the vehicle and receive networked emergency vehicle reservation information and passing information; Cameras are used to monitor the traffic flow conditions in each direction in real time and collect image information of vehicles on the road; The networked traffic signal light controller is used to calculate the timing plan, execute vehicle scheduling and control decisions on the status of the signal light; The intelligent control method of the traffic signal light with emergency vehicle priority comprises the following steps: Step 1, the networked traffic signal light controller performs vehicle dispatch initialization, including normal vehicle dispatch initialization and multi-priority emergency vehicle dispatch initialization; Step 2: If the wireless communication module does not receive the networked emergency vehicle reservation information, the networked traffic signal light controller performs ordinary vehicle dispatching, and the wireless communication module continues to monitor the networked emergency vehicle reservation information until the networked emergency vehicle reservation information is received. The networked traffic signal light controller sets the current traffic signal light to yellow and keeps it on for n seconds. d Execute step 3 at the same time; Step 3, if the wireless communication module receives the networked emergency vehicle reservation information, the networked traffic light controller performs multi-priority emergency vehicle dispatch, and at the same time, the wireless communication module monitors the networked emergency vehicle reservation information and emergency vehicle passing information, until there is no networked emergency vehicle reservation information and all networked emergency vehicle passing information is received, the networked traffic light controller performs step 2; Step 4, repeating steps 2 and 3 to realize intelligent control of traffic lights with priority for emergency vehicles; The ordinary vehicle dispatching in step 2 specifically includes the following sub-steps: Step 2.1, the networked traffic signal light controller obtains ordinary vehicle traffic density information based on road vehicle image information through an image recognition algorithm; The cameras in each direction collect n consecutive images within a fixed time interval Δt. b Frame road vehicle image information, 1≤n b ≤5, extract the number of vehicles in each lane on each frame image And obtain the waiting time of the first ordinary vehicle arriving at the intersection in each traffic flow Among them, L k Represents the lane to which it belongs, n b Represents the nth b frame; If the networked traffic signal light controller does not obtain the traffic density information of ordinary vehicles in the current road vehicle image, and all processing queues are empty, the traffic density information of ordinary vehicles is obtained again according to the real-time road vehicle image information; Step 2.2: If the networked traffic signal light controller obtains ordinary vehicle traffic density information, phase weight and timing calculation are performed according to the ordinary vehicle traffic density information, including: Traffic flow i In continuous n b The number of vehicles in the frame road vehicle image is Among them, n b is an integer greater than or equal to 1, the number of vehicles The calculation formula is expressed as: Then calculate the trend parameters of each traffic flow change The calculation formula is expressed as: Then the traffic flow tf i Weight The calculation formula is expressed as: Among them, u1 and u2 are weights, which are natural numbers used to adjust the influence factors of each parameter on the overall weight and also play a role in data standardization; Among them, f is the density function, and its input is the number of vehicles in each frame The output is the traffic density of the lane; P j The phase weight The calculation formula is expressed as: The networked traffic light controller calculates the timing and obtains the timing plan. If there are n intersections, c phases, and the i-th phase P i The weight is the largest, then P i The calculation formula of the obtained timing PT is expressed as: Among them, T is the maximum timing time that can be obtained for each phase and is set by the user; Step 2.3, the networked traffic signal light controller executes the timing plan and continuously monitors the networked emergency vehicle reservation information through the wireless communication module; If the wireless communication module does not receive the networked emergency vehicle reservation information, the networked traffic signal light controller waits for the current timing plan to end before recalculating the weights of each phase and regenerating the timing plan; If the wireless communication module receives the reservation information of the networked emergency vehicle, the networked traffic light controller will change the current phase to yellow light n seconds in advance, and add the networked emergency vehicle that has made the reservation to the networked emergency vehicle processing queue. Then perform multi-priority emergency vehicle dispatch.

2. According to claim 1, a method for intelligently controlling a traffic light with emergency vehicle priority, characterized in that: The vehicle scheduling initialization in step 1 specifically includes: Normal vehicle dispatch initialization: Initialize traffic flow tf according to the intersection shape i , 0≤i≤N-1, N≤3n a ; Among them, i is the number of the traffic flow in the intersection, n a is a positive integer representing the number of traffic coming from the intersection. Each incoming traffic has at most three directions: right turn, straight ahead, and left turn. Therefore, each intersection has at most 3n a traffic flow; a traffic flow tf i There is more than one lane in the system, let the kth lane be L k , each traffic flow corresponds to a set of lanes it contains Used to determine the traffic direction represented by the traffic flow through the traffic flow subscript; Initialize the set of all signal lights, that is, signal light group D P , initialize all weights, including traffic flow weights Phase Weight Traffic flow urgency weight Phase Urgency And initialize its value to 0; initialize the phase of all signal light groups to P 初始 ; Initialize each phase P j , and initialize its released traffic flow set Multi-priority emergency vehicle dispatch initialization: Each phase corresponds to a connected emergency vehicle processing queue The queue stores data structures describing the status information of connected emergency vehicles. <id,tf i ,v id ,t id ,e id >, where id is the unique identifier of the connected emergency vehicle, tf i is the traffic flow, v id is the speed, t id is the waiting time at the intersection, e id For urgency.

3. According to claim 2, a method for intelligently controlling a traffic light with emergency vehicle priority, characterized in that: The phase P j and the P 初始 Specifically: The phase P j Indicates signal light group D p Status: Where 0≤j≤M, M is the number of phases, P j,绿灯 Indicates that in phase P j Traffic light in medium green state, P j,红灯 The signal light is in red state; The P 初始 It is the initial phase, indicating that all lanes at the intersection are prohibited from passing when the system is started:

4. According to claim 1, a method for intelligently controlling a traffic light with emergency vehicle priority, characterized in that: The multi-priority emergency vehicle dispatch in step 3 specifically includes the following sub-steps: Step 3.1: The networked traffic light controller calculates the urgency of each phase, selects the phase with the greatest urgency, and releases the corresponding Traffic flow in Fill in the networked emergency vehicle status information according to the networked emergency vehicle reservation information obtained by the wireless communication module <id,tf i ,v id ,t id ,e id >, calculate the traffic flow emergency weight according to the networked emergency vehicle status information If tf i There are N connected emergency vehicles, and tf i The maximum speed limit is v max , then the traffic flow tf i The calculation formula of the traffic flow emergency weight is expressed as: Among them, r1, r2, r3, and r4 are weights, which are all natural numbers, used to adjust the influence factors of each parameter on the overall weight, and also play the role of data standardization; Phase P j Phase urgency The calculation formula is expressed as: Step 3.2, the wireless communication module continuously monitors the reservation information and passing information of the networked emergency vehicle; If the wireless communication module receives the information that the networked emergency vehicle has passed, the networked traffic light controller deletes The corresponding vehicle information is as follows; If all the passing information of the networked emergency vehicles in the phase is received, and there are still networked emergency vehicles in other phases, the networked traffic light controller re-executes the multi-priority emergency vehicle dispatch, otherwise it does not change the phase and waits for all the networked emergency vehicles in the phase to pass safely; If the connected emergency vehicle processing queue corresponding to each phase When both are empty, that is, when all the networked emergency vehicles on the road have passed the intersection, the networked traffic light controller executes ordinary vehicle scheduling, otherwise, re-executes multi-priority emergency vehicle scheduling.

5. The intelligent control method for traffic lights with emergency vehicle priority according to any one of claims 1 to 4, characterized in that: The ordinary vehicles include vehicles without networked communication modules installed, and vehicles with networked communication modules installed but without emergency vehicle reservation information issued; The networked emergency vehicle includes a vehicle equipped with a networked communication module and sending out emergency vehicle reservation information, and the emergency vehicles have different priorities.

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