A bus priority traffic light real-time timing optimization method, system and device

Abstract

This invention belongs to the field of intelligent transportation, specifically relating to a method, system, and device for real-time traffic light timing optimization with bus priority. It ensures bus priority by adjusting the green light duration in real-time at each intersection based on real-time traffic flow. The method includes the following steps: 1. Presetting the intersection's traffic rules, the range of green light control duration, and the traffic light changing sequence, and determining the initial traffic signal phase duration; 2. Monitoring and statistically analyzing vehicle arrival rates in each direction at the intersection using video surveillance equipment; 3. Calculating the average delay time in each direction at the intersection using a modified Webster model; 4. Calculating the total delay time in each direction at the intersection per unit time; 5. Reallocating the initial green light duration based on the total delay time; 6. Extending the green light in a timely manner according to the bus's location to ensure bus passage. This invention solves the problems of traffic light control communication modes being unsuitable for traffic flow changes, having low communication efficiency, and easily causing congestion.

Description

Technical Field

[0001] This invention belongs to the field of intelligent transportation, specifically relating to a method, system, and device for optimizing real-time traffic light timing for bus priority. Background Technology

[0002] With the development of electronic information technology and the advancement of urban transportation, the construction of three-dimensional transportation systems is becoming increasingly sophisticated. However, at the micro-level, the coordination between technology and the three key elements of transportation (people, vehicles, and roads) is insufficient. This seriously hinders the development of urban transportation systems, reduces the efficiency of the flow of goods and pedestrians, and exacerbates road congestion, especially during peak hours when traffic is heavy and pedestrians are sluggish. This not only reduces the experience for road users but also creates greater risks of road accidents.

[0003] Intelligent Traffic Systems (ITS) represent the future direction of transportation systems. They effectively integrate advanced information technology, data communication and transmission technology, electronic sensing technology, control technology, sensor technology, electronic control technology, automatic control theory, operations research, artificial intelligence, and other computer technologies into the entire ground traffic management system. This results in a comprehensive, real-time, accurate, and efficient transportation management system that operates across a wide area. Currently, the development of ITS is still in the early stages of research and testing; many new technologies are not yet mature and have not been widely adopted.

[0004] Taking traffic lights at intersections as an example, in a mature intelligent transportation system, traffic lights at intersections should be able to adaptively adjust according to the traffic flow on the road to maximize the vehicle capacity of the road. However, in the current stage of roads, the duration of traffic lights is mainly adjusted and preset by the traffic management department based on the spatiotemporal distribution characteristics of the traffic flow on the road. After the traffic signal system is debugged, the duration of traffic lights will remain fixed. This traditional method of traffic light management at intersections has at least the following disadvantages: (1) It cannot distinguish the traffic density of different types of vehicles, and cannot reasonably allocate the right-of-way between social vehicles and urban public transport systems, resulting in the inability to effectively improve the traffic volume on the road. (2) The timing of traffic lights at intersections cannot be dynamically adjusted according to peak or regular periods, resulting in severe road congestion during peak hours and limiting the efficiency of road traffic. (3) Some sections of roads with irregular structures are prone to traffic accidents due to road congestion, reducing the safety of road traffic. Summary of the Invention

[0005] In order to solve the problem that the timing of existing traffic lights cannot adapt to the spatiotemporal distribution of traffic flow, thereby reducing road traffic efficiency and safety;

[0006] This invention is achieved using the following technical solution:

[0007] A real-time traffic light timing optimization method prioritizing public transportation is provided. This method adjusts the green light duration in each phase at each intersection in real time based on real-time traffic flow, prioritizing public buses, thereby maximizing traffic flow. The traffic light timing optimization method provided by this invention includes the following steps:

[0008] 1. Preset the traffic rules for the intersection, preset the range of green light control duration and the sequence of traffic light changes, and determine the initial traffic signal phase duration.

[0009] 2. By installing video surveillance equipment, vehicles coming from all directions at the intersection are monitored in real time, distinguishing between buses and other vehicles and counting them; then, the arrival rate of buses in the i-th phase and j-th direction is calculated. and the arrival rate of social vehicles in the i-th phase and j-th direction

[0010] III. Calculating the average delay time d at the intersection in different phases and directions using the modified Webster model. ij :

[0011]

[0012] Where T represents the cycle length of the traffic light control signal; λ represents the effective green light duration; Q represents the traffic flow; and x represents the vehicle saturation on the road.

[0013] IV. Based on the arrival rates of buses and private vehicles in the i-th phase and j-th direction. and And the average delay time d(i,j), calculate the total delay time D in each phase and direction within a unit time t. ij :

[0014]

[0015] Among them, P s P represents the average number of passengers carried by a social vehicle. b This indicates the average number of passengers a bus can carry.

[0016] 5. Preset adjustment period Ts. After each adjustment period Ts is reached, calculate the total delay time D for each phase and direction based on the previous step. ij Following the principle that the longer the delay, the longer the green light duration, the initial green light duration t for each phase and direction within the light control signal cycle T is determined. ij Reassignment will be carried out.

[0017] VI. Within any traffic light cycle T, based on the monitored positions of buses traveling upwards on the road, determine the green light duration sufficient for buses to pass continuously, and extend the green light as needed, determining the extension time t. e :

[0018]

[0019] Among them, S v The distance between the video surveillance equipment and the monitored vehicle is represented by S; the distance between adjacent intersections is represented by v; the average speed of the vehicle is represented by t. s This indicates the average start-up time of the vehicle.

[0020] As a further improvement of the present invention, in step one, for a crossroads, straight ahead is denoted as s, left turn as l, east-west direction as 1, and north-south direction as 2. Then, the phase and direction codes of the traffic lights during the passage of traffic at the intersection include: east-west straight ahead s1, east-west left turn l1; north-south straight ahead s2, north-south left turn l2; the green light display sequence within a complete traffic light control cycle is: s1→l1→s2→l2.

[0021] As a further improvement of the present invention, in step one, the preset traffic rules stipulate that right-turning vehicles are not restricted by traffic light signals. In the initial traffic phase duration, the green light duration for left-turning and straight-going vehicles in the same direction is equal, and in each phase, the shortest green light duration is set to 20 seconds, and the longest green light duration is set to 120 seconds.

[0022] As a further improvement of the present invention, in step two, the arrival rate of buses and social vehicles in the i-th phase and j-th direction... and All are calculated using the following formula:

[0023]

[0024] As a further improvement of the present invention, in step five, the initial green light duration t for each phase and direction... ij The allocation method is as follows:

[0025] (1) Determine the original total green light duration t0 for each phase and direction of the current road segment.

[0026] (2) Obtain the total delay time D for each phase and direction. ij .

[0027] (3) Total delay time D for each phase and direction ij After normalization, the weights σ for each phase and direction are obtained. ij .

[0028] (4) The green light duration t for each phase and directionij The first constraint is that the green light duration should not exceed the preset range, and the second constraint is that the sum of the green light durations in all phases and directions should not exceed the original total green light duration t0; based on the weighting coefficient σ ij Green light duration t for each phase and direction ij Adjustments will be made.

[0029] As a further improvement of the present invention, in step five, the initial green light duration t for each phase and direction... ij The optimization function used in the allocation process is as follows:

[0030]

[0031] This invention includes a real-time traffic light timing optimization system for bus priority. It employs the aforementioned real-time traffic light timing optimization method for bus priority, adjusting the green light duration for each phase at each intersection in real time within a preset traffic control area. This real-time traffic light timing optimization system includes: video surveillance equipment, an image processing module, a target tracking module, an arrival rate statistics module, a delay time generation module, a green light duration update module, and a green light duration fine-tuning module.

[0032] Among them, video surveillance equipment is installed at each intersection within the traffic control area to capture images of vehicles coming from the opposite direction at each intersection.

[0033] The image processing module is used to acquire road condition images collected by video surveillance equipment, and then perform image recognition and target classification on the road condition images to identify buses and other vehicles passing by on the road.

[0034] The target tracking module is used to track the position of buses on the road based on the image recognition results from the image processing module, and to determine the vehicle's speed v and distance S. v .

[0035] The arrival rate statistics module is used to count the actual number of buses and private vehicles arriving on the current road segment within a preset sampling period, and then calculate the arrival rate of buses and private vehicles in the i-th phase and j-th direction. and

[0036] The delay time generation module is used to calculate the arrival rates of buses and private vehicles in the i-th phase and j-th direction based on the arrival rate statistics module. and And the average delay time d at the intersection in different phases and directions calculated using the modified Webster model. ij Generate the total delay time D for each phase and direction of the intersection within a unit time t. ij .

[0037] The green light duration update module is used to determine the total delay time D for each phase at each intersection based on the delay time generation module. ij The initial green light duration for each phase is periodically adjusted. This ensures that the initial green light duration for each phase does not exceed preset upper and lower limits, and that the newly adjusted initial green light duration for each phase is positively correlated with the total delay time in the previous sampling period.

[0038] The green light duration fine-tuning module is used to obtain the output of the target tracking module and extend the green light duration of the current phase when the bus approaches the intersection, ensuring that the bus approaching the intersection can pass quickly without exceeding the upper limit of the green light duration.

[0039] As a further improvement of the present invention, the data generation strategy of the delay time generation module is as follows:

[0040] First, the modified Webster model is used to calculate the average delay time d at the intersection in different phases and directions. ij :

[0041]

[0042] Where T represents the cycle length of the traffic light control signal; λ represents the effective green light duration; Q represents the traffic flow; and x represents the vehicle saturation on the road.

[0043] Then, the total delay time D in each phase and direction within a unit time t is calculated using the following formula. ij :

[0044]

[0045] Among them, P s P represents the average number of passengers carried by a social vehicle. b This indicates the average number of passengers a bus can carry.

[0046] As a further improvement of the present invention, the green light duration fine-tuning module generates the extension time t of the green light for each phase. e The formula is as follows:

[0047]

[0048] Among them, S v The distance between the video surveillance equipment and the monitored vehicle is represented by S; the distance between adjacent intersections is represented by v; the average speed of the vehicle is represented by t. s This indicates the average start-up time of the vehicle.

[0049] The present invention also includes a real-time traffic light timing optimization device for bus priority, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the aforementioned real-time traffic light timing optimization method for bus priority; furthermore, it periodically adjusts the green light duration of each phase in the next adjustment cycle based on the total delay time of each phase in the previous adjustment cycle; and within each traffic light control cycle, it appropriately extends the green light duration of the corresponding phase based on the approach status of the bus to the intersection, so as to ensure that buses approaching the intersection can pass quickly.

[0050] The technical solution provided by this invention has the following beneficial effects:

[0051] 1. This solution overcomes the problem that traditional traffic lights cannot assign different traffic priorities to different vehicles, thus hindering the improvement of passenger capacity per unit time. Through the object-oriented green light fine-tuning strategy in this invention, a public transport priority strategy can be implemented at the signal timing level, greatly alleviating travel pressure and improving traffic flow.

[0052] 2. The solution provided by this invention can optimize traffic light timing by using real-time traffic information uploaded by the road video monitoring system. By adaptively adjusting the green light duration of the signal to match the uneven spatial and temporal distribution of traffic flow on the road, the road's traffic capacity can be utilized to the maximum extent.

[0053] 3. Comparative simulation experiments show that this invention, by optimizing traffic light timing to prioritize bus passage, can increase traffic volume within a certain time frame, aligning with the people-oriented principle. Furthermore, by improving road traffic efficiency, this invention helps reduce the incidence of road congestion and enhances vehicle driving safety. Attached Figure Description

[0054] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0055] Figure 1 This is a flowchart of the steps in a real-time traffic light timing optimization method for bus priority provided in Embodiment 1 of the present invention.

[0056] Figure 2 This is a state diagram of east-west straight traffic flow with phase code s1 at an intersection.

[0057] Figure 3 This is a state diagram of east-west left-turning traffic flow with phase code l1 at an intersection.

[0058] Figure 4This is a state diagram of the north-south straight traffic flow with phase code s2 at an intersection.

[0059] Figure 5 This is a state diagram of north-south left-turning traffic flow with phase code l2 at an intersection.

[0060] Figure 6 This is a flowchart of the allocation method for redistributing the initial green light duration in each phase and direction in Embodiment 1 of the present invention.

[0061] Figure 7 This is a model diagram of the crossroads created during the simulation process of Embodiment 1 of the present invention.

[0062] Figure 8 This is a diagram illustrating the traffic flow during the simulation process of Embodiment 1 of the present invention.

[0063] Figure 9 This is an architecture diagram of a real-time traffic light timing optimization system for bus priority provided in Embodiment 2 of the present invention. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0065] Example 1

[0066] This embodiment provides a real-time traffic light timing optimization method prioritizing public transportation. It adjusts the green light duration for each phase at each intersection based on real-time traffic flow, prioritizing public buses, thereby maximizing traffic capacity. The main adjustment strategies of this method include periodic adjustment and object-oriented adjustment. "Periodic adjustment" analyzes whether the real-time traffic flow of each phase at the intersection matches the ideal traffic flow corresponding to the preset green light duration allocation scheme (in this embodiment, public buses and private vehicles are counted separately) within a preset sampling period. If they match, the current green light duration allocation scheme is maintained in the next sampling period; otherwise, the green light duration for each phase is reallocated based on the real-time traffic flow in the next sampling period. This ensures that phases with higher traffic flow receive greater passage authority, i.e., longer green light durations. "Object-oriented adjustment" identifies and classifies approaching vehicles at each intersection. When a public bus is detected, the green light duration is appropriately increased to ensure the public bus can pass quickly, essentially granting it greater "intersection passage" authority.

[0067] Specifically, such as Figure 1As shown, the traffic light timing optimization method provided in this embodiment includes the following steps:

[0068] Step 1: Preset the traffic rules for the intersection, preset the range of green light control duration and the sequence of traffic light changes, and determine the initial traffic signal phase duration.

[0069] To better distinguish traffic flow from different directions, this embodiment uses phase coding for vehicles traveling in different directions at intersections. Specifically, straight-ahead traffic is denoted as 's', left-turn traffic as 'l', east-west traffic as '1', and north-south traffic as '2', and so on. Figure 2-5 As shown, the phase and direction codes of the traffic lights during intersection passage include: east-west straight s1, east-west left turn l1; north-south straight s2, north-south left turn l2.

[0070] To better illustrate the solution in this embodiment, the following general assumptions are made for the traffic light-controlled passage scenario at an intersection:

[0071] (1) In the initial state, the maximum green light duration is 120 seconds, and the minimum duration is 20 seconds. Simultaneously, the green light duration is the same for vehicles turning left and going straight; the yellow light duration remains fixed. The green light display sequence within a complete light control signal cycle is: s1→l1→s2→l2.

[0072] (2) Due to the principle of bus priority, when a bus appears in a certain phase, the green light time of that phase should be increased, and we expect that the increased time will allow the bus to successfully pass the green light just from the edge of the video monitoring.

[0073] (3) All buses traveling on this section of road can be accurately identified. The starting time of buses and other vehicles is the same, and buses and other vehicles travel at the same speed and maintain a constant speed at the intersection.

[0074] Step 2: Monitor vehicles coming from all directions at the intersection in real time using installed video surveillance equipment, distinguish between buses and other vehicles, and count their numbers; then calculate the arrival rate of buses in the i-th phase and j-th direction. and the arrival rate of social vehicles in the i-th phase and j-th direction

[0075] In this embodiment, the green light duration for each phase is set based on the estimated theoretical traffic flow, while the arrival rate of buses and private vehicles in the i-th phase and j-th direction is... and All are calculated using the following formula:

[0076]

[0077] Step 3: Calculate the average delay time d at the intersection for different phases and directions using the modified Webster model. ij :

[0078]

[0079] Where T represents the cycle length of the traffic light control signal; λ represents the effective green light duration; Q represents the traffic flow; and x represents the vehicle saturation on the road.

[0080] Step 4: Based on the arrival rates of buses and private vehicles in the i-th phase and j-th direction. and And the average delay time d(i,j), calculate the total delay time D in each phase and direction within a unit time t. ij :

[0081]

[0082] Among them, P s P represents the average number of passengers carried by a social vehicle. b This indicates the average number of passengers a bus can carry.

[0083] Step 5: Preset adjustment period Ts. After each adjustment period Ts is reached, calculate the total delay time D for each phase and direction based on the previous step. ij Following the principle that the longer the delay, the longer the green light duration, the initial green light duration t for each phase and direction within the light control signal cycle T is determined. ij Reassignment will be carried out.

[0084] In this embodiment, as Figure 6 As shown, the initial green light duration t for each phase and direction ij The allocation method is as follows:

[0085] (1) Determine the original total green light duration t0 for each phase and direction of the current road segment.

[0086] (2) Obtain the total delay time D for each phase and direction. ij .

[0087] (3) Total delay time D for each phase and direction ij After normalization, the weights σ for each phase and direction are obtained. ij .

[0088] (4) The green light duration t for each phase and direction ij The first constraint is that the green light duration should not exceed the preset range, and the second constraint is that the sum of the green light durations in all phases and directions should not exceed the original total green light duration t0; based on the weighting coefficient σij Green light duration t for each phase and direction ij Make adjustments;

[0089] Specifically, the initial green light duration t for each phase and direction ij The optimization function used in the allocation process is as follows:

[0090]

[0091] Step Six: Within any traffic light cycle T, based on the monitored positions of buses traveling upwards on the road, determine the green light duration sufficient for buses to pass continuously, and extend the green light as needed, determining the extension time t. e :

[0092]

[0093] Among them, S v The distance between the video surveillance equipment and the monitored vehicle is represented by S; the distance between adjacent intersections is represented by v; the average speed of the vehicle is represented by t. s This indicates the average start-up time of the vehicle.

[0094] Simulation test

[0095] To compare whether the traffic light timing optimization scheme provided in this embodiment can improve the vehicle traffic efficiency at the intersection, this embodiment also uses the TraCI interface in the traffic model simulation tool SUMO to conduct simulation tests on the scheme of this embodiment and the traditional fixed-duration light-controlled traffic scheme, and statistically analyzes the test results of the two.

[0096] 1. Traditional solution

[0097] All vehicles proceed according to the established signals, with the signal light duration remaining fixed. The green light duration for vehicles turning left and going straight at intersections is the same; the yellow light duration remains fixed; vehicles turning right are not controlled by signals.

[0098] 2. Traffic light timing optimization scheme

[0099] When the TraCI control signal lights detect a bus in the north-south direction, the time of phase 3 is reduced or the time of phase 1 is increased. When no bus is detected in the north-south direction, the signal lights function normally.

[0100] (2.1) The rules for periodic regulation are as follows:

[0101] The sampling period is 10 minutes, meaning the green light duration for each phase at the intersection is updated every 10 minutes. Timing restarts when phase s1 ends. When the green light is in phase s2, the arrival rates of public and private vehicles in phase l2 within the monitoring range are recorded. When the green light is in phase l2, the arrival rates of the other three phases within the monitoring range are recorded, and the total delay is automatically calculated. Weights are determined based on the total delay, and the green light duration is reinitialized.

[0102] (2.2) The rules for object-oriented control are:

[0103] Throughout the process, the approach of buses to the intersection is constantly monitored, and the green light time is extended as needed to ensure the shortest green light time and the longest waiting time.

[0104] 3. Simulation of vehicle passage process

[0105] Create road networks and intersections in simulation software, where the intersection model is as follows: Figure 7 As shown in the diagram. A custom traffic flow is defined, with east-west traffic consisting of passengers and north-south traffic consisting of buses, with the number of buses being much smaller than that of passengers. It is assumed that a passenger vehicle carries a unit passenger capacity, while a bus vehicle carries four times the passenger capacity. A general simulation is performed, recording the traffic volume over half an hour. The simulation results are shown in the diagram. Figure 8 As shown.

[0106] Finally, the vehicle traffic data under the two different strategies were statistically analyzed: the traditional scheme had a traffic volume of 59 bus vehicles and 308 passenger vehicles, carrying 544 passengers. The scheme provided in this embodiment, however, had a traffic volume of 126 bus vehicles and 259 passenger vehicles, carrying 763 passengers. Analysis of the above database shows that the scheme provided in this embodiment increased the bus traffic volume by 113.6% compared to the traditional scheme, decreased the traffic volume of private vehicles by 15.9%, but increased the passenger capacity by 40.3%. Therefore, the scheme provided in this embodiment actually improves road traffic efficiency and has higher social value.

[0107] Example 2

[0108] Based on the scheme in Example 1, this embodiment further provides a real-time traffic light timing optimization system with bus priority. It employs the real-time traffic light timing optimization method with bus priority as described in Example 1, adjusting the green light duration for each phase at each intersection in real time within a preset traffic control area. Figure 9As shown, this type of real-time traffic light timing optimization system includes: video surveillance equipment, image processing module, target tracking module, arrival rate statistics module, delay time generation module; green light duration update module, and green light duration fine-tuning module.

[0109] The video surveillance equipment is installed at each intersection within the traffic control area to capture images of oncoming vehicles. An image processing module acquires these images, performs image recognition and target classification, and identifies buses and other vehicles passing by. A target tracking module tracks the location of buses on the road based on the image recognition results from the image processing module, determining their speed (v) and distance (S). v .

[0110] The arrival rate statistics module is used to count the actual number of buses and private vehicles arriving on the current road segment within a preset sampling period, and then calculate the arrival rate of buses and private vehicles in the i-th phase and j-th direction. and

[0111] The delay time generation module is used to calculate the arrival rates of buses and private vehicles in the i-th phase and j-th direction based on the arrival rate statistics module. and And the average delay time d at the intersection in different phases and directions calculated using the modified Webster model. ij Generate the total delay time D for each phase and direction of the intersection within a unit time t. ij The data generation strategy for the delay time generation module is as follows:

[0112] First, the modified Webster model is used to calculate the average delay time d at the intersection in different phases and directions. ij :

[0113]

[0114] Where T represents the cycle length of the traffic light control signal; λ represents the effective green light duration; Q represents the traffic flow; and x represents the vehicle saturation on the road.

[0115] Then, the total delay time D in each phase and direction within a unit time t is calculated using the following formula. ij :

[0116]

[0117] Among them, P s P represents the average number of passengers carried by a social vehicle. b This indicates the average number of passengers a bus can carry.

[0118] The green light duration update module is used to determine the total delay time D for each phase at each intersection based on the delay time generation module. ij The initial green light duration for each phase is periodically adjusted. This ensures that the initial green light duration for each phase does not exceed preset upper and lower limits, and that the newly adjusted initial green light duration for each phase is positively correlated with the total delay time in the previous cycle. The optimized function used in the green light duration update module is as follows:

[0119]

[0120] The green light duration fine-tuning module receives the output from the target tracking module and extends the green light duration for the current phase as a bus approaches the intersection, ensuring the bus can pass quickly without exceeding the maximum green light duration limit. The green light duration fine-tuning module generates the extension time t for each phase of the green light. e The formula is as follows:

[0121]

[0122] Among them, S v The distance between the video surveillance equipment and the monitored vehicle is represented by S; the distance between adjacent intersections is represented by v; the average speed of the vehicle is represented by t. s This indicates the average start-up time of the vehicle.

[0123] Example 3

[0124] Building upon embodiments 1 and 2, this embodiment further provides a real-time traffic light timing optimization device for bus priority, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the steps of the real-time traffic light timing optimization method for bus priority as described in embodiment 1.

[0125] In this embodiment, the real-time traffic light timing optimization device for bus priority is actually the data processing device used to implement the scheme in Embodiment 1. This data processing device is actually a type of computer device. The computer device in this embodiment can be an embedded terminal capable of executing programs, a tablet computer, a laptop computer, a desktop computer, a rack server, a blade server, a tower server, or a cabinet server (including independent servers or server clusters composed of multiple servers), etc. The computer device in this embodiment includes, but is not limited to, a memory and a processor that can communicate with each other via a system bus.

[0126] In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, etc. In some embodiments, the memory can be an internal storage unit of a computer device, such as the hard disk or RAM of the computer device. In other embodiments, the memory can also be an external storage device of the computer device, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the computer device. Of course, the memory can also include both internal storage units and external storage devices of the computer device. In this embodiment, the memory is typically used to store the operating system and various application software installed on the computer device. In addition, the memory can also be used to temporarily store various types of data that have been output or will be output.

[0127] In some embodiments, the processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. This processor is typically used to control the overall operation of a computer device. In this embodiment, the processor is used to run program code stored in memory or process data to execute steps such as the real-time traffic light timing optimization method for bus priority described in Embodiment 1. This achieves the following: periodically adjusting the green light duration of each phase in the next adjustment cycle based on the total delay time of each phase in the previous adjustment cycle; and appropriately extending the green light duration of the corresponding phase within each traffic light control signal cycle based on the approach status of the bus to the intersection, to ensure that buses approaching the intersection pass through quickly.

[0128] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A bus priority traffic light real-time timing optimization method, characterized in that, It is used for taking bus priority as principle, adjusting green light time length on each phase according to real-time traffic flow at each intersection, and realizing optimization target of maximum traffic flow; the traffic signal timing optimization method comprises the following steps: I. presetting traffic rules of intersection, presetting range of green light control time length and red-green light conversion sequence, and determining initial traffic signal phase time length; II. Real-time monitoring of vehicles in each direction at the intersection by installed video monitoring equipment, distinguishing among them buses and social vehicles and counting the number; further calculating the arrival rate of buses in the i-th phase in the j-th direction and the arrival rate of social vehicles in the i-th phase in the j-th direction III. Using the Modified Webster Model to Calculate Average Delay Time d for Different Phases and Directions at an Intersection ij : Wherein, T represents cycle length of light control signal cycle; λ represents effective green light time length; Q represents traffic flow; x represents vehicle saturation in road; Four, the arrival rate of buses and social vehicles in the i-th phase and j-th direction and and the average delay time d(i,j), the total delay time D in each phase and direction in unit time t is calculated ij : where P s represents the average number of people carried by a social vehicle; P b represents the average number of people carried by a bus; 5. Preset adjustment period Ts. After each adjustment period Ts is reached, calculate the total delay time D for each phase and direction based on the previous step. ij Following the principle that the longer the delay, the longer the green light duration, the initial green light duration t for each phase and direction within the light control signal cycle T is determined. ij Reassignment; Six, in any light control signal cycle T, according to the monitored bus position on the road to the top, determine the green light duration that meets the bus continuous passing, and extend the green light in time, determine the extension time t e : wherein S v represents the distance of the video monitoring device from the monitored vehicle; S represents the distance of the adjacent intersection; v represents the average speed of the vehicle; t s represents the average start-up time of the vehicle.

2. The bus priority traffic light real-time timing optimization method of claim 1, wherein: In step one, for cross intersection, straight line is recorded as s, left turn is recorded as l, east-west direction is recorded as 1, and south-north direction is recorded as 2, then phase and direction coding of light control signal in traffic process of intersection comprises: east-west straight line s1, east-west left turn l1; south-north straight line s2, south-north left turn l2; green light display sequence in a complete light control signal cycle is: s1→l1→s2→l2.

3. The transit priority traffic light real-time timing optimization method of claim 1, wherein: In step one, in preset traffic rules, right turn vehicle is not limited by light control signal; in initial traffic phase time length, green light time length of left turn and straight line vehicle in same direction is equal, and in each phase, the shortest time length of green light is set as 20 seconds, and the longest time length is set as 120 seconds.

4. The transit priority traffic light real-time timing optimization method of claim 1, wherein: In step two, the arrival rate of buses and social vehicles in the i-th phase and j-th direction and are calculated by the following formula:

5. The transit priority traffic light real-time timing optimization method of claim 1, wherein: In step five, the starting green light duration t in each phase and direction is allocated as follows: ij The allocation method is as follows: (1) determining original green light total time length t0 of each phase and direction on current road section; (2) Obtain the total delay time D in each phase and direction ij ; (3) Total delay time D in each phase and direction ij Normalization is performed to obtain the weight σ in each phase and direction ij ; (4) the green light duration t in each phase and direction ij The first constraint is that each green light duration t does not exceed a preset green light control duration range, and the second constraint is that the total of green light durations in all phases and directions does not exceed the original total green light duration t0. According to the weight coefficient σ ij The green light duration t in each phase and direction ij is adjusted.

6. The transit priority traffic light real-time timing optimization method of claim 5, wherein: In step five, the initial green light duration t in each phase and direction is allocated ij The optimization function used in the allocation process is as follows:

7. A transit priority traffic light real-time timing optimization system, characterized in that: It adopts the bus priority traffic signal real-time timing optimization method in any one of claims 1-6, and adjusts green light time length of each phase at each intersection in a preset traffic control range in real time; The traffic signal real-time timing optimization system comprises: Video monitoring device installed on each intersection of traffic control range in vehicle direction, for acquiring road condition image of each vehicle direction at intersection; Image processing module for acquiring road condition image collected by the video monitoring device, then performing image recognition and target classification on the road condition image, and identifying bus and social vehicle passing on the road; a target tracking module for tracking the position of the bus on the road based on the image recognition result of the image processing module, and determining the speed v and the distance S of the vehicle v ; An arrival rate statistics module is configured to count the actual number of buses and social vehicles arriving at the current road section in a preset sampling period, and then calculate the arrival rate of buses and social vehicles in the i-th phase and the j-th direction and a delay time generation module for generating total delay time D in each phase and direction of the intersection in unit time t according to the arrival rate of buses and social vehicles in the i-th phase and the j-th direction calculated by the arrival rate statistics module and and the average delay time d in different phases and directions of the intersection calculated by the modified Webster model ij , generating total delay time D in each phase and direction of the intersection in unit time t ij ; a green light duration updating module, configured to determine the total delay time D of each phase of each intersection according to the delay time generating module ij periodically adjusting the green light initial duration of each phase; ensuring that the green light initial duration of each phase does not exceed the preset upper and lower limits, and that the newly adjusted green light initial duration of each phase is positively correlated with the total delay time in the last period; and Green light time length fine adjustment module for acquiring output of the target tracking module, and prolonging green light time length of current phase when bus approaches intersection, ensuring that bus approaching intersection passes quickly on the basis of not exceeding upper limit of green light time length.

8. The transit priority traffic light real-time timing optimization system of claim 7, wherein: Data generation strategy of the delay time generation module is as follows: First, the average delay time d of different phases and directions at the intersection is calculated by using the modified Webster model ij : Wherein, T represents cycle length of light control signal cycle; λ represents effective green light time length; Q represents traffic flow; x represents vehicle saturation in road; The total delay time D in each phase and direction in unit time t is calculated by the following equation ij : where P s represents the average number of people carried by a social vehicle; P b represents the average number of people carried by a bus.

9. The transit priority traffic light real-time timing optimization system of claim 7, wherein: The green light length fine adjustment module generates the extension time t of each phase green light e The formula is as follows: wherein S v represents the distance of the video monitoring device from the monitored vehicle; S represents the distance of the adjacent intersection; v represents the average speed of the vehicle; t s represents the average start-up time of the vehicle.

10. A bus priority traffic light real-time timing optimization device, characterized in that, It comprises memory, processor, and computer program stored on memory and executable on processor, and the processor implements steps of the bus priority traffic signal real-time timing optimization method in any one of claims 1-6 when executing the computer program, and then realizes periodic adjustment of green light time length of each phase in next adjustment cycle according to total delay time of each phase in last adjustment cycle, and appropriately prolongs green light time length of corresponding phase in each light control signal cycle according to approaching state of bus and intersection, to ensure that bus approaching intersection passes quickly.

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