Intelligent traffic guide marking and intelligent traffic control method based on vehicle-road collaboration

Abstract

The present invention relates to a vehicle-road collaborative intelligent traffic guide marking and an intelligent traffic control method. A vehicle-road collaborative intelligent traffic guide marking comprises a ground photoelectric guide marking, a vehicle flow detection sensor and a control chip; the sensor detects the vehicle flow of each entrance lane phase green light time at a road intersection, and transmits the detected vehicle flow information data to the control chip; the control chip uses a signal timing optimization algorithm to calculate an optimized signal timing scheme based on the detected vehicle flow information, and transmits the optimized signal timing scheme to a signal controller. A road intersection intelligent traffic control method based on the vehicle-road collaborative intelligent traffic guide marking, connects the LED light strips laid in the guide arrows of the intersection motor vehicle entrance lane and the lane divider to the control chip, and the control chip is connected to the signal controller to achieve synchronous display of the color of the LED light strip and its corresponding direction signal light.

Description

Technical Field

[0001] The present invention relates to a method for controlling traffic signals at a road intersection, and in particular to an intelligent traffic guide marking at a road intersection and an intelligent traffic control method for vehicle-road collaboration. Background Art

[0002] With the continuous increase in the number of motor vehicles in my country, urban road traffic congestion and traffic pollution are becoming increasingly serious. Urban road intersections are nodes in the urban road network and play an important role in the urban road network, but they are also frequent points of traffic accidents and traffic congestion. The setting of traffic guide markings (motor vehicle entrance guide arrows and lane dividers) and signal lights at intersections plays an important role in guiding and controlling vehicles to pass through intersections efficiently and smoothly.

[0003] Existing road intersections have problems such as single function of traffic guide markings, low visibility at night and in foggy weather, and some intersection lights that cannot be set with green waves cannot dynamically adjust signal timing according to real-time traffic flow. Therefore, if the function of the ground guide markings at the entrance of the intersection can be increased so that they can emit light at night or when there is insufficient light, and the surface guide markings at the entrance of the intersection can be intelligently integrated with the traffic lights; through real-time traffic detection at the intersection, the effective coupling of intersection signal timing and traffic demand can be achieved, and the optimal signal timing after coupling can be fed back to the signal lights and intersection guide markings in real time through the signal control machine. This is of great significance for making full use of the intersection's spatiotemporal resources, reducing the exhaust pollution of motor vehicles at the intersection, improving the traffic efficiency of the intersection, and improving the traffic safety issues at the intersection.

[0004] In order to make full use of the time and space resources of intersections, reduce traffic accidents at intersections, and improve the efficiency of intersection traffic, relevant scholars at home and abroad have conducted design research on intersection guide markings. For example, the Chinese utility model patent (CN215164865U) discloses a ground traffic marking luminous indicator device, which mainly lays LED light strips around the zebra crossing, lane dividers and guide arrows at the intersection, and synchronizes their colors with the signal lights. The invention patent application with announcement number CN113793519A, "A lighting system for lane dividers at intersections linked with signal lights", lays LED lights on the lane dividers and links them with the signal lights in real time. The utility model patent (CN215417030U) discloses a road ground light control system linked with signal lights, burying geographic lights linked with signal lights on both sides of each lane divider at the intersection, so that the colors of the geographic lights and signal lights change synchronously. Xu Haoran, Cui Sheng, Jin Jiquan, etc. used video detectors and machine vision technology to take photos of the road surface for oncoming vehicles, detect whether there are vehicles in the lane where the green light is located, and dynamically adjust the signal timing based on the detection results (Intelligent traffic light system based on machine vision [J]. Hebei Agricultural Machinery, 2021(1): 88-89.). Yang Xuanbing, Meng Lingfei, etc. used infrared sensors to detect vehicle flow and designed a signal light that can be adjusted in real time (A design of an intelligent traffic light system based on Arduino UNO [J]. Yangtze River Information and Communication, 2021(2): 124-126.). Yao Y, Wang K, Xiong G. Use fixed cameras to collect traffic videos and use virtual coils to detect the flow of each lane (Embedded technology and algorithm for video-based vehicle queue length detection [C]. Service Operations and Logistics, and Informatics (SOLI), 2013 IEEE International Conference on. IEEE, 2013: 45-50.).

[0005] However, most of the current research on luminous traffic guide markings at road intersections focuses on lane dividers. Although a few scholars have studied guide arrows, the research content mainly focuses on the synchronous display of signal light color and marking color. Regarding intersection flow detection, most of the existing detection methods use video detection technology, and the cost of virtual coil detection is relatively high. What is important and critical is that the existing research does not use intersection guide markings to perform real-time detection of intersection vehicles, does not use vehicle detection results in a timely manner for dynamic adjustment of intersection signal timing, and does not transmit the signal timing adjustment results to the signal controller in a timely manner and realize real-time control of signal lights and ground guide markings through the signal controller. In this way, the dynamic balance between traffic demand and signal timing cannot be achieved, which is important for making full use of intersection spatiotemporal resources, improving intersection traffic efficiency, and then for smooth roads and reducing intersection vehicle exhaust emissions. Summary of the invention

[0006] In view of the shortcomings of the existing technology, the present invention proposes a vehicle-road collaborative intelligent traffic guide marking to improve the traffic efficiency and traffic safety of the intersection, which increases the function of the ground guide marking at the intersection and maximizes its efficiency.

[0007] At the same time, based on the intelligent traffic guide markings of vehicle-road collaboration, a intelligent traffic control method of vehicle-road collaboration at road intersections is proposed. Through dynamic closed-loop optimization of intersection signal timing, a dynamic balance between intersection signal control and traffic demand is achieved, thereby improving intersection traffic efficiency and traffic safety.

[0008] The present invention aims at the following problems: the visibility of the guide arrows and lane dividers of the motor vehicle entrance lanes at urban road intersections is low at night and in foggy weather. When the driver passes through the intersection, the front vehicle blocks the view and the driver cannot see the front signal light, causing vehicle delays, mistakenly running red lights and traffic congestion. In addition, some intersection signal lights cannot dynamically adjust the signal timing according to real-time traffic needs. The present invention proposes the following technical ideas:

[0009] Illuminating ground guide arrows and lane dividers are set at the entrance of the intersection, and their colors are synchronized with the traffic lights; a vehicle detector is set at the guide arrow to detect traffic flow information in real time; the detected vehicle information is automatically calculated by the signal timing algorithm to obtain a more optimized signal timing plan; finally, the optimized signal timing information is transmitted to the signal controller in real time, and the signal controller controls the traffic lights, guide arrows and lane dividers to achieve a dynamic closed loop.

[0010] Invention technical solution:

[0011] A vehicle-road collaborative intelligent traffic guide marking, comprising:

[0012] 1) A ground photoelectric guide marking composed of LED light strips is arranged at the guide arrows and lane dividers of the road intersections. A light-controlled switch is connected to the LED light strips of the photoelectric guide markings to control them to emit light in a dark light state; and the LED light strips are connected to the signal light control instructions output by the signal controller to achieve synchronous display of the color of the LED light strips and the color of the signal light;

[0013] 2) A vehicle flow detection sensor installed at the center of the guide arrow near the stop line; and

[0014] 3) Control chip;

[0015] The vehicle flow detection sensor detects the vehicle flow during the green light time of each entrance lane at the road intersection, and transmits the detected vehicle flow information to the control chip in real time;

[0016] The control chip uses a signal timing optimization algorithm to calculate an optimized signal timing plan based on the detected vehicle flow information, and transmits the optimized signal timing plan to the signal controller, which controls the traffic lights and the ground photoelectric guide markings to synchronize and dynamically link.

[0017] By setting a vehicle detector at the guide arrow, the traffic flow information is detected in real time; the control chip automatically calculates the optimal adjustment plan for the signal timing of the next cycle at the intersection based on the detected vehicle information (the traffic flow data of the last three consecutive cycles); finally, the optimized signal timing plan is transmitted to the signal controller in a timely manner, and the signal controller controls the synchronous linkage of the traffic lights and the ground traffic guide markings in real time, realizing dynamic closed-loop management of traffic control at road intersections, thereby achieving intelligent dynamic linkage between the intersection traffic lights and the ground traffic guide markings.

[0018] The vehicle-road collaborative intelligent traffic guide marking, the control chip uses the signal timing dynamic adjustment algorithm to dynamically optimize the intersection signal timing according to the detected traffic flow information, and calculates the optimized signal timing plan, and the process includes the following steps:

[0019] S1, detect the passing of vehicles within the last or n saturated headway time of the green light, and determine whether there are still queued vehicles that cannot pass or pass in advance at the end of the green light time of the lane;

[0020] S2: At intersections with a small proportion of large vehicles, detection can be performed in the last 5 seconds of the green light; at intersections with a large proportion of large vehicles, detection can be performed in the last 6 seconds of the green light; if two or more vehicles pass through the lane within the last 5 or 6 seconds of the green light, it is considered that there is a phenomenon that the queued vehicles did not completely pass through the intersection during the green light period; if one or no vehicle passes, it is considered that the green light time is not fully utilized and there is a waste of green light time;

[0021] S3, in order to eliminate the influence of accidental factors, take the results of 6 judgments in three consecutive cycles of the two opposite lanes in this phase. When 3 or more of the 6 judgments show that the queued vehicles have not completely passed through the intersection during the green light period, the green light time of this phase will be increased by 5s or 6s in the next cycle: when 2 or less of the 6 judgments show that the number of vehicles passing within the last 5s or 6s is less than one, the green light time of the corresponding phase of this lane will be reduced by 5s or 6s in the next cycle.

[0022] A method for intelligent traffic control at a road intersection based on the intelligent traffic guide marking of vehicle-road collaboration is provided, wherein the LED light strips laid in the guide arrows of the motor vehicle entrance lane and the lane dividers of the intersection are connected to a control chip, and the control chip is connected to a signal control machine, so as to realize synchronous display of the color of the LED light strips and the corresponding direction signal lights, and the process includes:

[0023] 1) Use infrared sensors to detect the number of vehicles passing through each import lane during the green light time of each signal cycle;

[0024] 2) The control chip uses the signal timing dynamic adjustment algorithm to dynamically optimize the intersection signal timing according to the detected traffic flow information, and finally transmits the optimized signal timing plan to the signal control machine in a timely manner.

[0025] In the intelligent traffic control method for road intersections, when vehicles queue up to pass through the intersection, the saturated headway time basically tends to be stable. Therefore, it is only necessary to detect whether there are saturated vehicles passing within the time of the last or n saturated headways of the green light, and it can be concluded with a high probability whether there are still queued vehicles at the end of the green light time of the lane that cannot pass or pass in advance.

[0026] In order to avoid being affected by chance, the intelligent traffic control method for road intersections can detect whether two or more vehicles pass within the last two saturated headway times of a green light; according to the distribution of saturated headway times between different vehicle type combinations, the detection can be performed in the last 5 seconds of the green light at intersections with a smaller proportion of large vehicles, and in the last 6 seconds of the green light at intersections with a larger proportion of large vehicles.

[0027] The control chip automatically determines whether there is a phenomenon of queued vehicles failing to fully pass through the intersection during the green light period based on the number of vehicles detected passing through the corresponding lane within the last 5s or 6s of the green light. If two or more vehicles pass through the lane within the last 5s or 6s of the green light, it is considered that there is a phenomenon of queued vehicles failing to fully pass through the intersection during the green light period. If one vehicle passes or no vehicle passes, it is considered that the green light time is not fully utilized and there is a waste of green light time.

[0028] In order to further eliminate the influence of randomness, the intelligent traffic control method for road intersections takes the results of 6 judgments in three consecutive cycles for the two opposite lanes of the phase. When there are 3 or more cases in the 6 judgments that the queued vehicles have not completely passed through the intersection during the green light period, the green light passage time of the phase will be increased by 5s or 6s in the next cycle: when there are 2 or less cases in the six judgments that the number of vehicles passing within the last 5s or 6s is less than one, the green light passage time of the corresponding phase of the lane will be reduced by 5s or 6s in the next cycle.

[0029] Beneficial effects of the invention:

[0030] 1. The vehicle-road collaborative intelligent traffic guide marking of the present invention increases the function of the ground guide marking at the intersection, and improves the traffic efficiency and traffic safety of the intersection. This study uses infrared sensor obstacle avoidance technology, light control technology, LED light strip display technology, chip control technology and signal timing optimization algorithm to design a smart traffic guide marking with four functions of automatic lighting at night and in foggy weather, synchronous display of signal light color, real-time detection of traffic flow on the entrance road, dynamic optimization of signal timing and timely feedback of optimization results to signal lights and guide markings, and coordinated linkage.

[0031] 2. The vehicle-road collaborative intelligent traffic guide marking of the present invention adopts a design scheme that links the guide arrows at the intersection entrance and the luminous guide markings of the lane dividers, which can correctly guide vehicles to pass through the intersection safely and efficiently under low visibility conditions, so as to maximize their efficiency.

[0032] 3. The present invention designs an installation method and protection measures for infrared sensor detectors in the guide arrows of the entrance lanes of intersections. An infrared sensor is installed in the guide arrows closest to the stop line of the entrance lanes of motor vehicles at the intersection to detect vehicle information. By analyzing the position and size of the guide markings at the intersection, the installation position, installation depth and protection measures of the infrared sensor for detecting vehicle flow and the LED light strip for realizing its active light emission are determined. The present invention designs the specific position, installation depth and protection measures for laying out the LED light strips on the guide arrows and lane dividers.

[0033] 4. The vehicle-road collaborative intelligent traffic guide marking of the present invention proposes a technology that connects the signal timing optimization adjustment scheme with traffic lights, ground LED light strips and vehicle detectors in real time, thereby realizing the dynamic coupling of the signal timing scheme with traffic demand and the dynamic optimization adjustment of the signal timing, reducing vehicle travel delays at intersections, improving intersection traffic efficiency, and reducing traffic pollution at intersections. Embedded technology is used to realize luminous intersection guide markings, linkage between guide markings and traffic lights, guide arrow line flow detection, and a dynamic optimization method for intersection signal timing based on guide arrow flow detection, thereby designing an intelligent traffic guide marking.

[0034] 5. The present invention proposes a smart traffic control method for road intersections based on vehicle-road collaboration. Based on the smart traffic guide markings based on vehicle-road collaboration, a dynamic balance between intersection signal control and traffic demand is achieved. It has the advantages of simple installation, low cost, high feasibility, rapid mass production, and no need for long-term on-site debugging. After being installed at the intersection, it can effectively improve the traffic efficiency of the intersection, improve the safety of the intersection, and reduce the exhaust emissions of motor vehicles at the intersection.

[0035] 6. The intelligent traffic control method for road-road coordination at road intersections of the present invention proposes a method for dynamically optimizing intersection signal timing according to whether the queued vehicles can completely pass through the intersection or pass through the intersection in advance during the green light period, and designs an adjustment optimization program. According to the saturated headway, a technology is proposed to detect the number of vehicles passing through the green light time in the last 5s (intersections with a smaller proportion of large vehicles) or 6s (intersections with a larger proportion of large vehicles) using a vehicle detector to determine whether there are queued vehicles that have not completely passed through the intersection or passed through the intersection in advance during the green light period.

[0036] 7. The present invention proposes a smart traffic control method for road-vehicle coordination at road intersections. It adopts infrared sensing technology, analyzes the saturated headway of queued vehicles, and intelligently determines whether there is a queuing phenomenon and then dynamically adjusts the signal timing through a smart signal light control algorithm. It realizes the comprehensive linkage of luminous guide markings, guide marking flow detection, dynamic adjustment of signal timing based on flow detection, and smart signal lights based on the signal timing adjustment results, thereby achieving a real-time dynamic balance between intersection signal control and traffic demand. The technical verification was carried out by making a physical model, and the results showed that the design scheme is feasible, can effectively improve the traffic efficiency and traffic safety of the intersection, and has a good prospect for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The technical route of the intelligent traffic guide marking and vehicle-road collaborative intelligent traffic control method of the present invention;

[0038] Figure 2 The figure shows the layout of the LED light strip with a directional arrow (going straight);

[0039] Figure 3 The figure shows the layout of the LED light strips on the lane dividers;

[0040] Figure 4 Shown is a schematic diagram of the embedded cross section of the LED light strip with guide arrows and lane dividers;

[0041] Figure 5 The figure shows the circuit diagram of the signal light, guide arrow and lane dividing line LED light linkage;

[0042] Figure 6The figure shows a cross-sectional schematic diagram of the infrared sensor layout at the intersection guide arrow;

[0043] Figure 7 The shown diagram is a flow detection circuit diagram with a guiding arrow;

[0044] Figure 8 Shown is a flow chart of the signal timing algorithm of the present invention;

[0045] Fig. 9 The figure shows the physical model making and function realization diagram;

[0046] Fig.10 The figure shows the overall circuit diagram of the intelligent traffic guide marking of the present invention;

[0047] In the figure, number 1 is a waterproof LED light strip, 2 is the guide arrow body, 3 is the lane dividing line body, 4 is transparent concrete, 5 is a large groove, 6 is a small groove, 7 is a uniform light plate, 8 is an infrared sensor, 9 is a waterproof metal shell, 10 is plastic steel mud; 11 is a power signal transmission line, and 12 represents the road surface. DETAILED DESCRIPTION

[0048] In order to make the technical concept and advantages of the invention more clearly understood, the technical solution of the invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the following embodiments are only used to explain and illustrate the preferred implementation methods of the invention and should not constitute a limitation on the scope of the patent protection required by the invention.

[0049] Example 1

[0050] See also Figure 1 The vehicle-road collaborative intelligent traffic guide marking of the present invention comprises:

[0051] 1) A ground photoelectric guide marking composed of LED light strips is arranged at the guide arrows and lane dividers of the road intersections. A light-controlled switch is connected to the LED light strips of the photoelectric guide markings to control them to emit light in a dark light state; and the LED light strips are connected to the signal light control instructions output by the signal controller to achieve synchronous display of the color of the LED light strips and the color of the signal light;

[0052] 2) A vehicle flow detection sensor installed at the center of the guide arrow near the stop line; and

[0053] 3) Control chip;

[0054] The vehicle flow detection sensor detects the vehicle flow during the green light time of each entrance lane at the road intersection, and transmits the detected vehicle flow information to the control chip in real time;

[0055] The control chip uses a signal timing optimization algorithm to calculate an optimized signal timing plan based on the detected vehicle flow information, and transmits the optimized signal timing plan to the signal controller, which controls the traffic lights and the ground photoelectric guide markings to synchronize and dynamically link.

[0056] The present invention detects the traffic flow information in real time by setting a vehicle detector at the guide arrow; the control chip automatically calculates the optimal adjustment plan for the signal timing of the next cycle of the intersection according to the detected vehicle information (preferably, using the traffic flow data of the latest three consecutive cycles); finally, the optimized signal timing plan is timely transmitted to the signal controller, and the signal controller controls the synchronous linkage of the traffic lights and the ground traffic guide markings in real time, so as to realize the dynamic closed-loop management of traffic control at the road intersection, thereby achieving the intelligent dynamic linkage between the intersection signal lights and the ground traffic guide markings.

[0057] Example 2

[0058] The vehicle-road collaborative intelligent traffic guide marking of this embodiment is different from that of Embodiment 1 in that it further limits the LED light strip to be arranged at the edge of the ground guide arrow at the entrance of the road intersection, and its contour shape is the same as the contour shape of the guide arrow; the LED light strip at the lane dividing line is arranged on the left lane dividing line of each motor vehicle entrance lane.

[0059] The schematic diagram of the layout of the intersection guide arrow LED light strip is as follows Figure 2 As shown in the figure (taking the straight line as an example, the others are the same), the layout diagram of the LED light strips on the lane dividers of the intersection is as follows Figure 3 In the figure, 1 is a waterproof LED light strip, 2 is a guide arrow body, 3 is a lane dividing line body, and 11 represents a power signal transmission line.

[0060] Example 3

[0061] See also Figure 4 The vehicle-road cooperative intelligent traffic guide marking of this embodiment is different from that of Embodiment 1 and Embodiment 2 in that the embedded cross-section design of the LED light strip in the intersection guide arrow and lane divider is further disclosed: Figure 4 As shown, the LED light strip is arranged in a large groove 5 with a depth of 18mm and a width of 10mm, a small groove 6 with a depth of 5mm and a width of 5mm is arranged in the middle of the large groove 5, a waterproof LED light strip with a width of 5mm and a thickness of 2mm is placed in the small groove, and a light homogenizing plate 7 with a width of 10mm and a thickness of 2mm is arranged above the small groove 6; finally, a transparent concrete 4 with a thickness of 16mm and a shape matching the large groove is embedded in the large groove to keep it horizontal with the ground; the LED light strip is connected to a light-controlled switch.

[0062] Example 4

[0063] See also Figure 6 The vehicle-road cooperative intelligent traffic guide marking of this embodiment is different from the previous embodiments in that the vehicle flow detection sensor 8 is further defined as being arranged in the middle of the first group of guide arrows near the stop line of each entrance lane. The sensor is packaged with a waterproof iron metal shell 9, and the shell and the road surface material are bonded with waterproof material plastic steel mud 10; the sensor is connected to the control chip through a wire. The cross-sectional diagram of the infrared sensor layout at the intersection guide arrow is shown in the figure below. Figure 6 As shown, 12 represents the road surface in the figure.

[0064] The infrared sensor is wrapped in a waterproof iron metal shell, and the shell and the road surface material are bonded with environmentally friendly, high-temperature resistant, and high-strength plastic-steel mud waterproof material. If the sensor fails, it can be directly removed from the shell and replaced, and the sensor should be set in the middle of the guide arrow to minimize vehicle crushing.

[0065] In actual application, considering the waterproof requirement, the vehicle flow detection sensor 8 can use the E18-D80NK infrared sensor, which has good waterproof, moisture-proof and anti-interference properties. The infrared sensor is connected to the control chip G431RBT6. When a vehicle passes above the sensor, the sensor will feedback information for automatic counting, and count once for each vehicle passing. The infrared sensor is used to detect the number of vehicles passing through the green light time of each import lane in each signal cycle, and the vehicle conditions detected in the last three cycles are used to make the latest signal timing adjustment, and then dynamically cycle.

[0066] The circuit diagram of the intelligent traffic guide marking line of the vehicle-road collaboration of the present invention, the signal light, the guide arrow and the lane dividing line LED light linkage is as follows Figure 5 As shown. The LED light strips laid in the guide arrows and lane dividers of the intersection motor vehicle entrance lanes are connected to the G431RBT6 chip, and the chip is connected to the signal controller. The signal timing information in the chip is transmitted to the LED light strip in real time to achieve synchronous display of the color of the LED light strip and its corresponding direction signal light. That is, when the corresponding signal light is red, the corresponding light strip synchronously displays the red light, when it is green, it synchronously displays the green light, and when it is yellow, the light strip flashes yellow. The G431RBT6 control chip selected here has the characteristics of low power consumption, low voltage, fast speed and high accuracy. This design can expand the display range of the signal light and solve the problem that the driver cannot see the signal light due to blocked vision or dim vision.

[0067] The schematic diagram of the intelligent traffic guide marking line and the flow detection circuit of the guide arrow of the vehicle-road collaboration of the present invention is as follows Figure 7As shown. By installing a vehicle detector in the middle of the guide arrow in front of the stop line, the detected vehicle information is transmitted to the signal controller in real time, and the signal control information optimized by the signal controller is dynamically fed back to the signal light and LED light strip in real time, which can effectively improve the traffic efficiency of the intersection. An infrared sensor is installed at the guide arrow. The infrared sensor detects the number of vehicles passing through each lane during the green light time, and transmits the detected vehicle information to the G431RBT6 chip, which is the basis for the subsequent dynamic signal timing optimization.

[0068] Infrared sensor installation location: The "Urban Road Traffic Signs and Markings Setting Specifications" (GB51038-2015) stipulates that two or more sets of guide arrows should be set at the entrance of the intersection. The first set is set 1m to 5m away from the stop line, and the second set is set at the starting position of the guide lane. The infrared sensor is placed in the middle of the first set of guide arrows near the stop line of each entrance lane, and the infrared sensor is connected to the G431RBT6 chip. When a vehicle passes above the sensor, the sensor will feedback information for automatic counting, and count once for each vehicle passing. Use the infrared sensor to detect the number of vehicles passing through the green light time of each entrance lane in each signal cycle, and use the number of vehicles detected in the last three cycles to make the most recent signal timing adjustment, and then dynamically cycle.

[0069] Considering the waterproof requirement, the E18-D80NK infrared sensor can be used, which has good waterproof, moisture-proof and anti-interference properties. The infrared sensor is wrapped with a waterproof iron metal shell, and the shell and the road surface material are bonded with environmentally friendly, high-temperature resistant, high-strength plastic steel mud waterproof material. If the sensor fails, it can be directly removed from the shell and replaced, and the sensor is set in the middle of the guide arrow to minimize vehicle rolling.

[0070] The control chip uses a signal timing dynamic adjustment algorithm to dynamically optimize the intersection signal timing according to the detected traffic flow information, and calculates the optimized signal timing scheme. The process includes the following steps:

[0071] S1, detect whether there are any vehicles passing within the time of the last green light or n saturated headway, and determine whether there are still queued vehicles that cannot pass or pass in advance at the end of the green light time of the lane;

[0072] S2: At intersections with a small proportion of large vehicles, detection can be performed in the last 5 seconds of the green light; at intersections with a large proportion of large vehicles, detection can be performed in the last 6 seconds of the green light; if two or more vehicles pass through the lane within the last 5 or 6 seconds of the green light, it is considered that there is a phenomenon that the queued vehicles did not completely pass through the intersection during the green light period; if one or no vehicle passes, it is considered that the green light time is not fully utilized and there is a waste of green light time;

[0073] S3, in order to eliminate the influence of accidental factors, take the results of 6 judgments in three consecutive cycles of the two opposite lanes in this phase. When 3 or more of the 6 judgments show that the queued vehicles have not completely passed through the intersection during the green light period, the green light time of this phase will be increased by 5s or 6s in the next cycle: when 2 or less of the 6 judgments show that the number of vehicles passing within the last 5s or 6s is less than one, the green light time of the corresponding phase of this lane will be reduced by 5s or 6s in the next cycle.

[0074] Fig.10 This is the overall circuit schematic diagram of the vehicle-road collaborative intelligent traffic guide marking of the present invention.

[0075] Example 5

[0076] This embodiment is a method for intelligent traffic control at road intersections based on the aforementioned intelligent traffic guide markings of vehicle-road collaboration. The LED light strips laid in the guide arrows of the motor vehicle entrance lane and the lane dividers of the intersection are connected to the control chip, and the control chip is connected to the signal control machine to realize the synchronous display of the color of the LED light strip and the corresponding direction signal light. The process includes:

[0077] 1) Use infrared sensors to detect the number of vehicles passing through each import lane during the green light time of each signal cycle;

[0078] 2) The control chip uses the signal timing dynamic adjustment algorithm to dynamically optimize the intersection signal timing according to the detected traffic flow information, and finally transmits the optimized signal timing plan to the signal control machine in a timely manner.

[0079] The technical route of the intelligent traffic control method for road intersections of the present invention is as follows Figure 1 shown.

[0080] Considering that the saturated headway time is basically close to being stable when vehicles queue up to pass through the intersection, it is only necessary to detect whether there are saturated vehicles passing through within the last or n saturated headway times of the green light, and it can be concluded with a high probability whether there are still queued vehicles that cannot pass or pass in advance at the end of the green light time of the lane.

[0081] To avoid being affected by chance, it is possible to detect whether two or more vehicles pass within the last two saturated headway times of the green light. According to the distribution of saturated headway times between different vehicle type combinations, it is possible to choose to detect the last 5 seconds of the green light at intersections with a smaller proportion of large vehicles, and to detect the last 6 seconds of the green light at intersections with a larger proportion of large vehicles.

[0082] Example 6

[0083] The intelligent traffic control method for road intersections of the present invention is different from that of Example 5 in that: the control chip automatically determines whether there is a phenomenon that queued vehicles in the lane have not completely passed through the intersection during the green light period based on the number of vehicles detected passing through within the last 5 seconds or 6 seconds of the green light of the corresponding lane; if two or more vehicles pass through the lane within the last 5 seconds or 6 seconds of the green light, it is considered that there is a phenomenon that queued vehicles have not completely passed through the intersection during the green light period; when one vehicle passes or no vehicle passes, it is considered that the green light time is not fully utilized and there is a waste of green light time.

[0084] Furthermore, in order to eliminate the influence of randomness, the results of 6 judgments in three consecutive cycles of the two opposite lanes in this phase are taken. When 3 or more of the 6 judgments show that the queued vehicles have not completely passed through the intersection during the green light period, the green light time of this phase will be increased by 5s or 6s in the next cycle: when 2 or less of the six judgments show that the number of vehicles passing through in the last 5s or 6s is less than one, the green light time of the corresponding phase of this lane will be reduced by 5s or 6s in the next cycle.

[0085] Example 7

[0086] The present invention aims to solve the problems of low visibility of guide arrows and lane dividers at the entrances of urban road intersections at night and in foggy weather. When passing through intersections, drivers cannot see the traffic lights ahead due to the large vehicles blocking their line of sight, causing vehicle delays, mistakenly running red lights and traffic jams. In addition, some intersection traffic lights cannot dynamically adjust the signal timing according to real-time traffic needs. The present invention proposes the following technical concepts: illuminating ground guide arrows and lane dividers are set at the entrances of intersections, and their colors are synchronized with the traffic lights; vehicle detectors are set at the guide arrows to detect traffic flow information in real time; the detected vehicle information is automatically calculated by the signal timing algorithm to obtain a more optimized signal timing plan; and finally the optimized signal timing information is transmitted to the signal controller in real time, and the signal controller controls the traffic lights, guide arrows and lane dividers to achieve a dynamic closed loop. Figure 1As shown, LED light strips are arranged at the intersection guide arrows and lane dividers, and light-controlled switches are used to control them to emit light in dim light conditions; the signal light control instructions output by the signal control machine are connected to the LED light strips arranged on the ground to achieve synchronous display of the light strip color and the signal light color; an infrared sensor is installed at the center of the guide arrow near the stop line to detect the traffic flow of each phase of the green light time of each entrance lane of the intersection, and the detected traffic flow information is transmitted to the G431RBT6 chip in real time; the chip automatically calculates the optimal adjustment plan for the signal timing of the intersection in the next cycle based on the detected traffic flow data of the last three consecutive cycles; finally, the adjusted signal timing plan is transmitted to the signal lights and ground traffic guide markings in a timely manner to realize a closed loop, thereby achieving intelligent dynamic linkage between the intersection signal lights and ground traffic guide markings. The overall circuit schematic diagram of the intelligent traffic guide markings for vehicle-road collaboration of the present invention is shown in the figure. Fig.10 shown.

[0087] According to the above design ideas, this design scheme consists of four modules, each of which is described as follows:

[0088] 1. Design of luminous intersection guide markings

[0089] In order to increase the visualization of intersection guide arrows and lane dividers, and reduce the low traffic efficiency and traffic safety problems caused by drivers not being able to see the markings in low visibility conditions, the intersection traffic guide arrows and lane dividers are designed to be luminous. The specific method adopted in this embodiment is: by setting a groove with the same shape as the guide arrow contour and a depth of 18mm and a width of 10mm on the edge of the guide arrow on the ground of the intersection entrance, and setting a small groove with a depth of 5mm and a width of 5mm in the middle of the groove, and placing a waterproof LED light strip with a width of 5mm and a thickness of 2mm in the small groove, each LED light can display three colors: red, green and yellow, and adding a light-distributing plate with a width of 10mm and a thickness of 2mm above the small groove for light guide isolation design to make the light soft and uniform; finally, a transparent concrete with a thickness of 16mm, a suitable shape and detachable is embedded in the groove to keep it level with the ground. The LED light strips at the lane dividers are set in the same way as the guide arrows. Since the driving position of vehicles in my country is set on the left side of the vehicle, LED light strips are set on the left lane dividers of each motor vehicle import lane to remind drivers of the current direction of travel. The LED light strips are connected to the light control switch, and the light intensity threshold value is set to control it to automatically emit light when the external ambient light becomes dim.

[0090] Using LED light strips as the light source is environmentally friendly and inexpensive. Using transparent concrete can increase the durability and compression resistance of the guide arrows, and make the light emitted by the LED light strips uniform and soft; the two grooves can increase the waterproof ability of the LED lights in the guide arrows and prevent them from being crushed. If the LED light strips are repaired and maintained, the transparent concrete blocks can be directly taken out to repair the LED light strips. Since the LED light strips are set at the solid line part of the lane divider in front of the stop line of the intersection and at the guide arrows, the crushing of the LED light strips by passing vehicles can be effectively reduced, thereby extending the service life of the LED light strips. The schematic diagram of the layout of the LED light strips for the guide arrows at the intersection is shown in the figure. Figure 2 As shown in the figure (taking the straight line as an example, the others are the same), the layout diagram of the LED light strips on the lane dividers of the intersection is as follows Figure 3 As shown in the figure, the embedded cross-section design of the LED light strip in the intersection guide arrow and lane divider is as follows Figure 4 shown.

[0091] 2. Linkage design between guide markings and signal lights

[0092] The LED light strips laid in the guide arrows and lane dividers of the motor vehicle entrance lanes at the intersection are connected to the G431RBT6 chip, and the chip is connected to the signal controller, and the signal timing information in the chip is transmitted to the LED light strip in real time, so as to realize the synchronous display of the color of the LED light strip and its corresponding direction signal light. That is, when the corresponding signal light is red, the corresponding light strip synchronously displays the red light, when it is green, it synchronously displays the green light, and when it is yellow, the light strip flashes yellow light. The G431RBT6 control chip selected here has the characteristics of low power consumption, low voltage, fast speed and high precision. This design can expand the display range of the signal light and solve the problem that the driver cannot see the signal light due to blocked vision or dim vision. The circuit diagram of the linkage between the signal light and the guide arrow and lane divider LED light is as shown in the figure Figure 5 shown.

[0093] 3. Guide arrow flow detection

[0094] By installing a vehicle detector in the middle of the guide arrow in front of the stop line, the detected vehicle information is transmitted to the signal controller in real time, and the signal control information optimized by the signal controller is dynamically fed back to the signal light and LED light strip in real time, which can effectively improve the traffic efficiency of the intersection. An infrared sensor is installed at the guide arrow. The infrared sensor detects the number of vehicles passing through each lane during the green light time, and transmits the detected vehicle information to the G431RBT6 chip, which is the basis for the subsequent dynamic signal timing optimization.

[0095] Infrared sensor installation location: The "Urban Road Traffic Signs and Markings Setting Specifications" (GB51038-2015) stipulates that two or more sets of guide arrows should be set at the entrance of the intersection. The first set is set 1m to 5m away from the stop line, and the second set is set at the starting position of the guide lane. The infrared sensor is placed in the middle of the first set of guide arrows near the stop line of each entrance lane, and the infrared sensor is connected to the G431RBT6 chip. When a vehicle passes above the sensor, the sensor will feedback information for automatic counting, and count once for each vehicle passing. Use the infrared sensor to detect the number of vehicles passing through the green light time of each entrance lane in each signal cycle, and use the number of vehicles detected in the last three cycles to make the most recent signal timing adjustment, and then dynamically cycle.

[0096] Considering the waterproof requirement, the E18-D80NK infrared sensor can be used. This sensor has good waterproof, moisture-proof and anti-interference properties. The infrared sensor is wrapped in a waterproof iron metal shell, and the shell and the road surface material are bonded with environmentally friendly, high-temperature resistant, high-strength plastic steel mud waterproof material. If the sensor fails, it can be directly removed from the shell and replaced, and the sensor is set in the middle of the guide arrow to minimize vehicle rolling. The cross-sectional diagram of the infrared sensor layout at the intersection guide arrow is shown in the figure below. Figure 6 As shown, the schematic diagram of the flow detection circuit with the guiding arrow is as follows Figure 7 shown.

[0097] 4. Dynamic optimization design of intersection signal timing based on guide arrow flow detection

[0098] This study uses the signal timing dynamic adjustment method to dynamically optimize the intersection signal timing.

[0099] When vehicles queue up to pass through an intersection, the saturated headway is basically close to being stable. Therefore, it is only necessary to detect whether there are saturated vehicles passing through within the last or n saturated headway times of the green light, and it is possible to determine with a high probability whether there are still queued vehicles that cannot pass through or pass through in advance at the end of the green light time of the lane. To avoid the influence of chance, it is possible to detect whether there are two or more vehicles passing through within the last two saturated headway times of the green light. The saturated headway values ​​of intersections are shown in Table 1 (Zhao Xing, Ren Gang. Analysis of Headway Characteristics of Signalized Intersections [J]. Journal of Transportation Engineering and Information, 2010, 8(1):103-108.). Therefore, at intersections with a small proportion of large vehicles, detection can be performed in the last 5 seconds of the green light, and at intersections with a large proportion of large vehicles, detection can be performed in the last 6 seconds of the green light.

[0100] Table 1 Distribution of saturated headway times between various vehicle types

[0101] Model combination Car - Car Small car - large car Cart - Car Cart - Cart Saturated headway mean 1.7173728 1.9971875 2.3531111 3.1416666 variance 0.1031374 0.0622724 0.1572173 0.0703362

[0102] The infrared sensor installed in the guide arrow will detect the number of vehicles passing through the corresponding lane within the last 5 seconds (or 6 seconds) of the green light. After the infrared sensor detects, it will immediately transmit the detected data to the G431RBT6 chip, and the chip automatically determines whether there is a phenomenon that the queued vehicles in the lane have not completely passed through the intersection during the green light. The judgment basis is: if two or more vehicles pass through the last 5 seconds (or 6 seconds) of the green light in the lane, it is considered that there is a phenomenon that the queued vehicles have not completely passed through the intersection during the green light; if one vehicle passes or no vehicle passes, it is considered that the green light time is not fully utilized and there is a waste of green light time.

[0103] To further eliminate the impact of chance, the results of six consecutive judgments in three cycles for the two opposite lanes of this phase are taken. If there are three or more cases in the six judgments that the queued vehicles have not completely passed the intersection during the green light period, the green light passage time of this phase will be increased by 5s (or 6s) in the next cycle: if there are two or less cases in the six judgments that the number of vehicles passing in the last 5s (or 6s) is less than one, the green light passage time of the corresponding phase of the lane will be reduced by 5s (or 6s) in the next cycle. The algorithm flow is as follows: Figure 8 shown.

[0104] Since the above algorithm requires the number of vehicles in the first three cycles to make the first cycle adjustment, the system only detects the vehicle flow without making any adjustments in the first to third cycles when the system is turned on. After detecting three cycles, dynamic optimization and adjustment will be performed starting from the fourth cycle.

[0105] The above algorithm is repeated to achieve dynamic optimization and adjustment of signal timing. In order to avoid the signal cycle of the signal light being too long or too short during the timing process, the shortest green light time of each phase is set to 10s, the longest green light time is 40s, and the longest cycle is 132s. When applied to actual intersections, the shortest green light time, the longest green light time and the longest cycle should be comprehensively determined based on the scale of the intersection and traffic demand.

[0106] In order to verify the feasibility of this design, the research team made a model. This model takes four phases as an example. When the machine is turned on, the default is left turn in the east-west direction, and the travel time is 20s (that is, the left turn in the east-west direction is green, and the green light duration is 20s). Then it is straight travel in the east-west direction, and the travel time is 30s. Then it is left turn in the north-south direction, and the time is also 20s. Finally, it is straight travel in the north-south direction, and the time is 30s. The simulation model is as follows Fig. 9 The physical model demonstration shows that this design is feasible and achieves the expected effect.

[0107] Based on the above, the present invention is to enhance the function of the ground guide markings (motor vehicle entrance guide arrows and lane dividers) at the intersection of urban roads, realize the intelligent guidance of the ground guide markings, and detect the traffic demand of the intersection in real time through the vehicle detector set in the guide markings, and transmit the detection results to the signal timing optimization adjustment program in time, and then control the traffic lights and ground guide markings in real time through the traffic signal machine after the adjusted signal timing, so as to realize the dynamic closed-loop optimization of the intersection signal timing, which plays an important role in making full use of the time and space resources of the intersection, improving the traffic efficiency of the intersection, and reducing the exhaust emissions of vehicles at the intersection. The active luminous ground guide markings are set by using LED light strips and light-controlled switches, so that they can actively emit light at night and in foggy weather, and are linked with the intersection signal lights, so that the driver can correctly choose the lane and pass through the intersection smoothly when the vision is poor or the vision is blocked. An infrared vehicle detector is set in the guide arrow of the entrance lane of the intersection to automatically detect the vehicle traffic conditions of each lane in real time. The real-time traffic flow conditions detected by the infrared detector are automatically transmitted to the signal timing optimization adjustment program control chip. The control chip transmits the optimized intersection signal timing results to the signal controller in a timely manner. The signal controller transmits the optimized signal timing instructions to the traffic lights and ground guide markings, thereby realizing a dynamic closed loop of traffic demand and signal timing and intelligent signal display.

[0108] The production and demonstration of the physical model show that the design idea of ​​the present invention is complete, the design scheme is feasible, and the system cost is low. It realizes the functions of luminous guide markings, guide marking flow detection, dynamic adjustment and optimization of signal timing, and coordinated linkage of intelligent traffic lights. It realizes the dynamic balance between intersection signal control and traffic demand, as well as the intelligent display of intersection guide markings, and achieves the design goal of improving intersection traffic efficiency and traffic safety.

[0109] The above description is only a preferred embodiment of the present invention and does not constitute a limitation of the present invention. Under the guidance of the prior art, those skilled in the art can make other modifications to the implementation of the present invention without creative work. Any modification made within the spirit and principle of the present invention or simple replacement or equivalent substitution using conventional technical means in the field should be included in the protection scope of the present invention.

Claims

1. A vehicle-road collaborative intelligent traffic guide marking, characterized in that: include: 1) A ground photoelectric guide marking composed of LED light strips is arranged at the guide arrows and lane dividers of the road intersections. A light-controlled switch is connected to the LED light strips of the photoelectric guide markings to control them to emit light in a dark light state; and the LED light strips are connected to the signal light control instructions output by the signal controller to achieve synchronous display of the color of the LED light strips and the color of the signal light; 2) A vehicle flow detection sensor installed at the center of the guide arrow near the stop line; and 3) Control chip; The vehicle flow detection sensor detects the vehicle flow during the green light time of each entrance lane at the road intersection, and transmits the detected vehicle flow information to the control chip in real time; The control chip uses a signal timing dynamic adjustment algorithm to dynamically optimize the intersection signal timing according to the detected vehicle flow information, and calculates the optimized signal timing scheme, and the process includes: Step S1, detecting the passing of vehicles within the last or n saturated headway times of the green light, and determining whether there are still queued vehicles that cannot pass or pass ahead at the end of the green light time of the lane; Step S2: At intersections with a small proportion of large vehicles, detection can be performed in the last 5 seconds of the green light; at intersections with a large proportion of large vehicles, detection can be performed in the last 6 seconds of the green light; if two or more vehicles pass through the last 5 or 6 seconds of the green light of the lane, it is considered that there is a phenomenon that the queued vehicles have not completely passed through the intersection during the green light period; if one or no vehicle passes through, it is considered that the green light time is not fully utilized and there is a waste of green light time; Step S3, in order to eliminate the influence of accidental factors, the results of 6 consecutive determinations of the two opposite lanes in this phase are taken. If there are 3 or more cases in which the queued vehicles fail to completely pass through the intersection during the green light period in 6 determinations, the green light passage time of this phase will be increased by 5s or 6s in the next cycle; if there are 2 or less cases in which the number of vehicles passing through the intersection in the last 5s or 6s in 6 determinations, the green light passage time of the corresponding phase of this lane will be reduced by 5s or 6s in the next cycle; The control chip transmits the optimized and adjusted signal timing scheme to the signal controller, and the signal controller controls the traffic lights and the ground photoelectric guide markings to dynamically link synchronously.

2. The vehicle-road collaborative intelligent traffic guide marking according to claim 1 is characterized by: The LED light strip is arranged at the edge of the ground guide arrow at the entrance of the road intersection, and its outline shape is the same as the outline shape of the guide arrow; the LED light strip at the lane dividing line is arranged on the left lane dividing line of each motor vehicle entrance lane.

3. The intelligent traffic guide marking for vehicle-road collaboration according to claim 1 or 2, characterized in that: The LED light strip is arranged in a large groove with a depth of 18mm and a width of 10mm, a small groove with a depth of 5mm and a width of 5mm is arranged in the middle of the large groove, a waterproof LED light strip with a width of 5mm and a thickness of 2mm is placed in the small groove, and a light homogenizing plate with a width of 10mm and a thickness of 2mm is arranged above the small groove; finally, transparent concrete with a thickness of 16mm and a shape matching the large groove is embedded in the large groove to keep it level with the ground; the LED light strip is connected to a light-controlled switch.

4. The intelligent traffic guide marking for vehicle-road collaboration according to claim 1 or 2, characterized in that: The vehicle flow detection sensor is arranged in the middle position of the first group of guide arrows near the stop line of each import lane. The sensor is packaged with a waterproof iron metal shell, and plastic steel mud waterproof material is used to bond the shell and the road surface material; the sensor is connected to the control chip through a wire.

5. A method for intelligent traffic control at a road intersection based on the intelligent traffic guide markings of vehicle-road collaboration as claimed in claim 1, wherein the LED light strips laid in the guide arrows of the motor vehicle entrance lane and the lane dividers of the intersection are connected to a control chip, and the control chip is connected to a signal control machine, so as to realize the synchronous display of the color of the LED light strips and the corresponding direction signal lights, characterized in that: 1) Use infrared sensors to detect the number of vehicles passing through each import lane during the green light time of each signal cycle; 2) The control chip uses the signal timing dynamic adjustment algorithm to dynamically optimize the intersection signal timing according to the detected traffic flow information, and finally transmits the optimized signal timing plan to the signal control machine in a timely manner.

6. The intelligent traffic control method for road intersections according to claim 5 is characterized in that: When vehicles queue up to pass through an intersection, the saturated headway time basically tends to be stable. Therefore, it is only necessary to detect whether there are saturated vehicles passing through within the last or n saturated headway times of the green light, and it can be concluded with a high probability whether there are still queued vehicles at the end of the green light time of the lane that cannot pass or pass in advance.

7. The intelligent traffic control method for road intersections according to claim 5 or 6, characterized in that: To avoid being affected by chance, it is possible to detect whether two or more vehicles pass within the last two saturated headway times of the green light. According to the distribution of saturated headway times between different vehicle type combinations, it is possible to choose to detect the last 5 seconds of the green light at intersections with a smaller proportion of large vehicles, and to detect the last 6 seconds of the green light at intersections with a larger proportion of large vehicles.

8. The intelligent traffic control method for road intersections according to claim 7 is characterized in that: The control chip automatically determines whether there are any queued vehicles in the lane that have not completely passed the intersection during the green light period based on the number of vehicles detected passing through the corresponding lane within the last 5 or 6 seconds of the green light. If two or more vehicles pass through the lane within the last 5 seconds or 6 seconds of the green light, it is considered that the queued vehicles did not fully pass through the intersection during the green light period; if one or no vehicle passes, it is considered that the green light time is not fully utilized and there is a waste of green light time.

9. The intelligent traffic control method for road intersections according to claim 8 is characterized in that: To further eliminate the impact of randomness, the results of a total of 6 judgments in three consecutive cycles on the two opposite lanes of this phase are taken. When 3 or more of the 6 judgments show that the queued vehicles did not completely pass through the intersection during the green light period, the travel time of this phase will be increased by 5s or 6s in the next cycle: when 2 or less of the 6 judgments show that the number of vehicles passing through the intersection in the last 5s or 6s is less than one, the travel time of the corresponding phase of this lane will be reduced by 5s or 6s in the next cycle.

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