Traffic flow accurate intervention system and method based on electronic light curtain

Abstract

The invention provides a traffic flow accurate intervention system and method based on an electronic light curtain. The system comprises a data processing unit, an information detection unit, an advanced early warning unit, a variable speed limiting unit, an electronic light curtain unit and a light beam induction unit. And the data processing unit is respectively connected with the information detection unit, the advanced early warning unit, the variable speed limiting unit, the electronic light curtain unit and the light beam induction unit. The invention provides a traffic flow active accurate intervention method based on vehicle operation safety and congestion degree, and a traffic flow accurate intervention system based on an electronic light curtain is constructed by taking tunnel electromechanical facilities as a basis and fusing an electronic light curtain technology, so that multi-mode accurate intervention of advanced early warning of the front section of a hole, hole blocking and active induction in the hole is realized, and the traffic flow accuracy is improved. The system makes up the limitation and practicability of a single management and control mode system, effectively solves the problem of tunnel secondary accidents, relieves the road congestion pressure caused by tunnel traffic accidents, and has practical application value in the aspects of road traffic management and control.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent traffic control, and specifically relates to a precise traffic flow intervention system and method based on an electronic light curtain. Background Art

[0002] With the rapid increase in highway construction mileage and car ownership, road traffic safety issues are becoming increasingly serious, especially in tunnel sections, where secondary traffic accidents are very likely to occur, causing serious damage to people's lives and property safety. According to the investigation, the probability of accidents in tunnels and the severity of accidents are significantly higher than those in ordinary sections. At present, for highway tunnel sections, especially tunnel-dense areas, video event monitoring is mainly used to monitor the tunnels, and based on the monitoring results, vehicles on the road before the tunnel entrance are controlled.

[0003] However, the existing methods of tunnel video event monitoring and control of road vehicles in front of the tunnel entrance have the following shortcomings: the control measures of prohibiting all road vehicles from passing in front of the tunnel entrance are generally adopted, and the control mode of road vehicles in front of the tunnel entrance is single, resulting in high road congestion pressure caused by tunnel traffic accidents, which has great limitations in road traffic management and control. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a precise traffic flow intervention system and method based on an electronic light curtain, which can effectively solve the above problems.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention provides a precise traffic flow intervention system based on an electronic light curtain, comprising: a data processing unit, an information detection unit, an advance warning unit (1), a variable speed limit unit (2), an electronic light curtain unit (3) and a light beam induction unit (4); the data processing unit is connected to the information detection unit, the advance warning unit (1), the variable speed limit unit (2), the electronic light curtain unit (3) and the light beam induction unit (4) respectively;

[0007] The information detection unit is installed in the monitored tunnel, and is used to detect and obtain the tunnel monitoring image of the entire monitoring area of ​​the tunnel in real time, and send it to the data processing unit in real time;

[0008] The data processing unit is installed in the monitoring center and is used to analyze the tunnel monitoring image and identify whether a tunnel emergency occurs based on the current tunnel monitoring image; and when a tunnel emergency is identified, obtain a road traffic control decision L; and according to the road traffic control decision L, control the advance warning unit (1), the variable speed limit unit (2), the electronic light curtain unit (3) and the light beam induction unit (4), thereby actively and accurately intervening in the real-time traffic conditions of the tunnel during the handling of the tunnel emergency.

[0009] Preferably, the number of the advance warning units (1) is two, namely: a first advance warning unit (1.1) and a second advance warning unit (1.2); the number of the variable speed limit units (2) is two, namely: a first variable speed limit unit (2.1) and a second variable speed limit unit (2.2);

[0010] In the direction from far to near the tunnel entrance, a first advance warning unit (1.1), a first variable speed limit unit (2.1), a second advance warning unit (1.2), a second variable speed limit unit (2.2) and an electronic light curtain unit (3) are sequentially arranged in front of the tunnel entrance;

[0011] Wherein: each of the advanced warning units (1) comprises a variable information board, a controller and a warning support frame;

[0012] Each of the variable speed limit units (2) comprises a variable speed limit display screen and a speed limit support frame;

[0013] The electronic light curtain unit (3) comprises a concentrated light beam (3.1), an aerosol spraying device (3.2) and a control device (3.3); and is used to implement blocking and warning of passing vehicles through light and shadow imaging technology;

[0014] The light beam induction unit (4) is arranged in the tunnel, and comprises a projection device (4.1) and a ground projection light beam arranged on the ground in the tunnel; wherein the ground projection light beam comprises 6 projection beam light strips and four projection induction arrow light strips, which are respectively:

[0015] The first lane right-turn projection beam light strip (A1) is arranged in the first lane; the second lane right-turn projection beam light strip (A21) and the second lane left-turn projection beam light strip (A22) are arranged in the second lane; the third lane left-turn projection beam light strip (A3) is arranged in the third lane; the 1st-2nd middle section projection beam light strip (A1-2) is arranged between the first lane and the second lane; the 2nd-3rd middle section projection beam light strip (A2-3) is arranged between the second lane and the third lane;

[0016] The first lane right turn projection induction arrow light strip (B1) is arranged in the first lane; the second lane right turn projection induction arrow light strip (B21) and the second lane left turn projection induction arrow light strip (B22) are arranged in the second lane; the third lane left turn projection induction arrow light strip (B3) is arranged in the third lane.

[0017] The present invention also provides a method for a traffic flow precision intervention system based on an electronic light curtain, comprising the following steps:

[0018] Step S1, using the video monitoring facilities in the tunnel to monitor the entire monitoring area of ​​the tunnel in real time, and sending the tunnel monitoring images to the data processing unit in real time;

[0019] Step S2, the data processing unit analyzes the tunnel monitoring image in real time to determine whether a tunnel emergency occurs inside the tunnel; if so, further identifies the following tunnel emergency related information, including: the occurrence time T of the tunnel emergency, the occurrence location of the tunnel emergency inside the tunnel, the lane occupation of the tunnel emergency, and the event type Z of the tunnel emergency; wherein the lane occupation of the tunnel emergency includes whether each lane is occupied by the tunnel emergency, and the occupied area ratio of the occupied lane; the event type Z of the tunnel emergency includes safe passage events and unsafe passage events;

[0020] Step S3, the data processing unit estimates the time h required for handling the tunnel emergency according to the lane occupation of the tunnel emergency; according to the occurrence time T of the tunnel emergency and the time h required for handling the tunnel emergency, the road congestion degree estimation algorithm is used to estimate the road congestion degree P when the tunnel emergency is handled when no traffic intervention measures are adopted in the process of handling the tunnel emergency;

[0021] Step S4, the data processing unit obtains a road traffic control decision L according to the event type Z of the tunnel emergency, the road congestion level P, and the lane occupancy caused by the tunnel emergency;

[0022] Step S5: The data processing unit actively and accurately intervenes in the real-time traffic conditions of the tunnel according to the road traffic control decision 1 during the handling of tunnel emergencies.

[0023] Preferably, step S2 specifically comprises:

[0024] Step S2.1, the data processing unit reads that the number of lanes in the monitored tunnel is three, which are lane 1, lane 2 and lane 3 in the tunnel width direction;

[0025] The data processing unit identifies the lane lines in the tunnel monitoring image at the current monitoring time T, thereby performing image segmentation on the tunnel monitoring image to obtain a first lane area, a second lane area, and a third lane area;

[0026] Step S2.2, for the identified u-th lane area, u=1, 2, 3, the following method is used to determine whether a tunnel emergency occurs, whether the u-th lane area is occupied, and if it is occupied, determine the proportion of the occupied area of ​​the u-th lane area by the tunnel emergency:

[0027] Step S2.2.1, dividing the u-th lane area into M*N grids according to the preset grid side length;

[0028] For each grid (x m ,y n ), where x m and n are the row and column numbers of the grid, m = 1, 2, ..., M, n = 1, 2, ..., N, and the following method is used to identify whether it is abnormal at the current monitoring time T:

[0029] If the following formulas (1), (2) and (3) are satisfied at the same time, the grid (x m ,y n ) Conclusion of abnormality at the current monitoring time T:

[0030] |f T (x n ,y n )-f T-ΔT (x n ,y n )|≤Δf(1)

[0031] |f T (x n ,y n )-f T+ΔT (x n ,y n )|≤Δf(2)

[0032] |f T (x n ,y n )-f0(x n ,y n )|>Δf(3)

[0033] Where: f T (x n ,y n ) represents the grid (x m ,y n ) The image feature value at the current monitoring time T; fT-ΔT (x n ,y n ) represents the grid (x m ,y n ) The image feature value at the previous monitoring time T-ΔT; f T+ΔT (x n ,y n ) represents the grid (x m ,y n ) is the image feature value at the next monitoring time T+ΔT; ΔT is the time interval for acquiring tunnel monitoring images; Δf is the image feature recognition threshold; f0(x n ,y n ) represents the pre-stored grid (x m ,y n ) background image standard feature value, meaning: grid (x m ,y n ) when there are no vehicles or people on the road surface in the tunnel area;

[0034] Specifically, when formula (1) and formula (2) are established, it means that the grid (x m ,y n ) at the current monitoring time T, the difference between the image feature value at the previous monitoring time T-ΔT is small; at the same time, the difference between the image feature value at the next monitoring time T+ΔT is small, which means that the grid (x m ,y n ) is located in the tunnel area, and no moving object enters at the current monitoring time T; when formula (3) is established, it represents the grid (x m ,y n ) at the current monitoring time T, the image feature value is different from the standard feature value of the background image, which means that the grid (x m ,y n ) There are nearly stationary vehicles and people on the road surface of the tunnel area; therefore, when formula (1), formula (2) and formula (3) are all valid, the grid (x m ,y n ) The conclusion that a tunnel emergency occurs at the current monitoring time T, and the grid (x m ,y n ) Conclusion of abnormality at the current monitoring time T;

[0035] Step S2.2.2, at the current monitoring time T, in the first lane area, the second lane area, and the third lane area, as long as one abnormal grid is identified, it is concluded that a tunnel emergency occurs inside the tunnel;

[0036] For the u-th lane area, in its M*N grids, as long as one abnormal grid is identified, it is concluded that the tunnel emergency occupies the u-th lane; when the u-th lane is occupied by the tunnel emergency, the following formula is used to obtain the occupied area ratio Pr of the u-th lane by the tunnel emergency u :

[0037] Pr u =Num u (abnormal) / M*N (4)

[0038] Where: Num u (abnormal) represents the number of abnormal grids in the u-th lane area at the current monitoring time T; M*N represents the total number of grids in the u-th lane area.

[0039] Preferably, when a tunnel emergency event is identified to occur inside the tunnel, the following method is used to identify the event type Z of the tunnel emergency event:

[0040] Construct an emergency event type library; determine the scope of safe passage events and the scope of unsafe passage events in the emergency event type library; match the identified tunnel emergency event with the emergency event type library to determine the event type Z of the tunnel emergency event.

[0041] Preferably, safe passage events include vehicle rear-end collisions, scratches, and breakdowns, which have no impact on the passage of other vehicles in the tunnel; unsafe passage events include tunnel vehicle fires and accidents involving hazardous chemicals vehicles, which have an impact on the safety of other vehicles in the tunnel.

[0042] Preferably, step S3 specifically comprises:

[0043] Step S3.1: Estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] when no traffic intervention measures are adopted [T,T+h] ;

[0044] Step S3.2, using formula (5), obtain the road congestion level P when the tunnel emergency is handled:

[0045]

[0046] Where: m is the number of tunnel lanes; m l is the number of lanes occupied by tunnel emergencies; C is the designed traffic capacity of the tunnel.

[0047] Preferably, step S3.1 is specifically as follows:

[0048] Step S3.1.1, establish a two-layer architecture database and update it dynamically in real time;

[0049] In the two-layer database, the first layer is the traffic volume record information of the previous year, and the data record includes: the daily traffic volume of the previous year and the daily traffic volume growth coefficient; wherein the daily traffic volume of the previous year is expressed as traffic volume i=1,2,.....,365, represents the total traffic volume on the i-th day of the previous year; the daily traffic volume growth coefficient of the previous year is expressed as Represents the growth coefficient of the traffic volume on the i-th day of the previous year compared to the traffic volume on the i-1th day of the previous year;

[0050] For traffic volume Further recorded is the hourly traffic volume and hourly traffic volume ratio of the i-th day of the previous year; among which, the hourly traffic volume of the i-th day of the previous year is expressed as j=1,2,.....,24, meaning: the j-th hourly traffic volume on the i-th day of the previous year; the hourly traffic volume ratio coefficient on the i-th day of the previous year is expressed as Meaning: the traffic volume in the jth hour on the i-th day of the previous year The traffic volume on the i-th day of the previous year proportion;

[0051] The next layer is the traffic volume record information for this year, which has the same structure as the data record of the previous year and is dynamically filled in by hour based on time axis;

[0052] Step S3.1.2, when the occurrence time T of the tunnel emergency event is identified, the day D of the tunnel emergency event occurrence time T in the current year is obtained, that is, the tunnel emergency event occurs at the Tth hour of the Dth day of the current year; here, T is the time expressed in 24-hour format, and T is an integer hour or a non-integer hour;

[0053] Step S3.1.3, use formula (6) to estimate the traffic volume on the Dth day of the year

[0054]

[0055] in:

[0056] Represents the traffic volume on day D-1 of the current year;

[0057] Represents the traffic growth coefficient on the Dth day of the previous year;

[0058] represents the traffic growth coefficient of the i-th day of the year; represents the traffic growth coefficient of the i-th day of the previous year; The meaning is: the sum of the difference in traffic growth coefficients from day 1 to day D-1 in this year and the previous year;

[0059] Step S3.1.4, determine whether the tunnel emergency incident handling end time T+h and the tunnel emergency incident occurrence time T are on the same day, that is, determine whether the relationship T+h≤24 holds; if so, it indicates that they are on the same day, and execute step S3.1.5; otherwise, it indicates that they cross days, that is, the tunnel emergency incident handling end time T+h is on the D+1 day, and execute step S3.1.6;

[0060] Step S3.1.5, using formula (7), estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] [T,T+h] :

[0061]

[0062] in: represents the traffic volume at hour [T]-1 on day D of the current year; where [T] represents T rounded down to an integer;

[0063] Represents the sum of the traffic volume share coefficients from hour [T] to hour [T+h] on day D of the previous year; where [T+h] represents T+h rounded down to an integer;

[0064] Step S3.1.6, using formula (8), estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] [T,T+h] :

[0065]

[0066] in: Represents the estimated traffic volume from the time T when the tunnel emergency occurred to 24:00 on the D day of the current year; represents the traffic volume on the Dth day of the current year, specifically the total traffic volume on the Dth day of the current year; is the total traffic volume from hour 1 to hour [T] on day D of the current year, directly read from the database in step S3.1.1; represents the traffic volume from hour [T] to hour T on day D of the current year, directly read from the database in step S3.1.1;

[0067] Represents the estimated traffic volume from 0:00 to T+h-24 on the D+1 day of the current year; represents the traffic volume on day D of the previous year; Represents the total traffic volume from hour 1 to hour [T+h-24] on day D+1 of the previous year; It represents the traffic volume at hour [T+h-24+1] on day D+1 of the previous year; h-[h] represents the decimal part of the time h required for handling tunnel emergencies; [h] represents the integer rounded down for h.

[0068] Preferably, step S4 is specifically:

[0069] Step S4.1: presetting a threshold δ of the road congestion level P P ;

[0070] If the road congestion level P≤δ P , then the road traffic control decision L shown in formula (9) is executed; if the road congestion level P>δ P , then the road traffic control decision L shown in formula (10) is executed:

[0071]

[0072] Among them: u Represents the lane number occupied by the tunnel emergency; the monitored tunnel has three lanes, namely lane 1, lane 2 and lane 3; l u =1, 2, 3, representing that the tunnel emergency occupies lane 1, lane 2, and lane 3 respectively; l u =0, indicating that the tunnel emergency does not occupy any lane;

[0073] Z=0, representing the event type Z of the tunnel emergency event as an unsafe passage event;

[0074] Z = 1, representing that the event type Z of the tunnel emergency is a safe passage event;

[0075] Pr1, Pr2, and Pr3 represent the proportion of the occupied area of ​​lane 1, lane 2, and lane 3 by tunnel emergencies, respectively;

[0076] Pr0 represents the preset threshold value of the ratio of tunnel emergencies to lane occupancy area.

[0077] Preferably, step S5 is specifically:

[0078] (I) Intervention methods when L = 0:

[0079] When L=0, it means that during the tunnel emergency handling process, all lanes of the controlled tunnel are blocked. At this time:

[0080] Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message: "Accident ahead, slow down"; the second advance warning unit (1.2) at the near end displays a warning message: "Accident ahead, please stop";

[0081] Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "40", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "X";

[0082] Electronic light curtain unit (3): in working state, the light curtain displays the blocking information of “X stop X”;

[0083] Beam guidance unit (4): all projection beam light strips are in a constant on state, preventing the vehicle from moving forward; all projection guidance arrow light strips are in an off state;

[0084] (II) Intervention methods when L=1:

[0085] When L=1, it means that during the tunnel emergency handling process, lane 1 is safe for traffic:

[0086] Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message: "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message: "drive according to the guidance in the light and shadow guidance area";

[0087] Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "60", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "40";

[0088] Electronic light curtain unit (3): in a closed state;

[0089] Beam induction unit (4):

[0090] The left-turn projection beam light strip (A22) in the second lane, the left-turn projection beam light strip (A3) in the third lane, and the projection beam light strip between the second and third lanes (A2-3) are always on, preventing vehicles from passing through the second and third lanes;

[0091] The left-turn projection induction arrow light strip (B22) in the second lane and the left-turn projection induction arrow light strip (B3) in the third lane are in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0092] (III) Intervention methods when L=2:

[0093] When L=2, it means that during the tunnel emergency handling process, lane 3 is safe for traffic:

[0094] Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message: "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message: "drive according to the guidance in the light and shadow guidance area";

[0095] Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "60", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "40";

[0096] Electronic light curtain unit (3): in a closed state;

[0097] Beam induction unit (4):

[0098] The right-turn projection beam light strip (A1) in lane 1, the right-turn projection beam light strip (A21) in lane 2, and the projection beam light strip between lanes 1 and 2 (A1-2) are always on, preventing vehicles from passing through lanes 1 and 2;

[0099] The right-turn projection induction arrow light strip (B1) in lane 1 and the right-turn projection induction arrow light strip (B21) in lane 2 are in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0100] (IV) Intervention methods when L=3:

[0101] When L=3, it means that during the tunnel emergency handling process, lanes 2 and 3 are safe for traffic:

[0102] Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message: "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message: "drive according to the guidance in the light and shadow guidance area";

[0103] Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "80", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "60";

[0104] Electronic light curtain unit (3): in a closed state;

[0105] Beam induction unit (4):

[0106] The right-turn projection beam light strip (A1) in lane 1 and the projection beam light strip (A1-2) in the middle section of lane 1-2 are always on, preventing vehicles from passing through lane 1;

[0107] The right-turn projection induction arrow light strip (B1) in lane 1 is in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0108] (V) Intervention methods when L=4:

[0109] When L=4, it means that during the tunnel emergency handling process, lanes 1 and 2 are safe for traffic:

[0110] Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message: "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message: "drive according to the guidance in the light and shadow guidance area";

[0111] Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "80", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "60";

[0112] Electronic light curtain unit (3): in a closed state;

[0113] Beam induction unit (4):

[0114] The left-turn projection beam light strip (A3) in lane 3 and the projection beam light strip (A2-3) in the middle section of lane 2-3 are always on, preventing vehicles from passing through lane 3;

[0115] The left-turn projection guidance arrow light strip (B3) in lane 3 is in the on-guiding state, and the other projection guidance arrow light strips are in the off state;

[0116] (VI) Intervention methods when L=5:

[0117] When L=5, it means that no tunnel emergency occurs and lanes 1, 2, and 3 are all safe for traffic:

[0118] Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message: "Be careful in the tunnel ahead", and the second advance warning unit (1.2) at the near end displays a warning message: "Slow down in the light and shadow guidance area".

[0119] Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "100", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "80";

[0120] Electronic light curtain unit (3): in a closed state;

[0121] Beam induction unit (4):

[0122] The 1st-2nd middle projection beam light strip (A1-2) and the 2nd-3rd middle projection beam light strip (A2-3) are in a long-period flashing guidance state to prevent driving fatigue; all other projection beam light strips are in an off state;

[0123] All projection induction arrow light strips are turned off.

[0124] The traffic flow precision intervention system and method based on electronic light curtain provided by the present invention has the following advantages:

[0125] The present invention discloses a precise traffic flow intervention system and method based on electronic light curtains, which utilizes electronic light curtain technology to achieve precise intervention in the operating status of road traffic flow, proposes an active precise traffic flow intervention method based on vehicle operating safety and congestion level, and builds a precise traffic flow intervention system based on electronic light curtains based on tunnel electromechanical facilities and integration of electronic light curtain technology, thereby achieving multi-mode precise intervention of advance warning at the front of the tunnel entrance, blocking at the tunnel entrance, and active induction in the tunnel, making up for the limitations and practicality of a single control mode system, effectively solving the problem of secondary accidents in tunnels, and alleviating the pressure of road congestion caused by tunnel traffic accidents, and having practical application value in road traffic management and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0126] Figure 1 A schematic diagram of the layout structure of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention;

[0127] Figure 2 A schematic diagram of a precise traffic flow intervention system based on an electronic light curtain provided by the present invention;

[0128] Figure 3 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention;

[0129] Figure 4 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention when L=0;

[0130] Figure 5 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention when L=1;

[0131] Figure 6 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention when L=2;

[0132] Figure 7 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention when L=3;

[0133] Figure 8 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention when L=4;

[0134] Fig. 9 A working state diagram of a traffic flow precision intervention system based on an electronic light curtain provided by the present invention when L=5. DETAILED DESCRIPTION

[0135] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0136] The present invention discloses a precise traffic flow intervention system and method based on electronic light curtains, which utilizes electronic light curtain technology to achieve precise intervention in the operating status of road traffic flow, proposes an active precise traffic flow intervention method based on vehicle operating safety and congestion level, and builds a precise traffic flow intervention system based on electronic light curtains based on tunnel electromechanical facilities and integration of electronic light curtain technology, thereby achieving multi-mode precise intervention of advance warning at the front of the tunnel entrance, blocking at the tunnel entrance, and active induction in the tunnel, making up for the limitations and practicality of a single control mode system, effectively solving the problem of secondary accidents in tunnels, and alleviating the pressure of road congestion caused by tunnel traffic accidents, and having practical application value in road traffic management and control.

[0137] See also Figure 1 to Figure 3 The present invention provides a precise traffic flow intervention system based on an electronic light curtain, comprising: a data processing unit, an information detection unit, an advance warning unit 1, a variable speed limit unit 2, an electronic light curtain unit 3 and a light beam induction unit 4; the data processing unit is respectively connected to the information detection unit, the advance warning unit 1, the variable speed limit unit 2, the electronic light curtain unit 3 and the light beam induction unit 4; the data processing unit performs linkage control on the optoelectronic equipment facilities in the supervised area of ​​the highway tunnel section to achieve precise intervention in road traffic flow.

[0138] The present invention mainly realizes the active and precise induction and interference of vehicles on the tunnel road section. The system makes full use of the detection data of the existing video surveillance and other information detection units in the tunnel, combines the various functional modules of the system, and utilizes the active and precise intervention method of traffic flow based on the vehicle operation status. During the handling of emergencies in the tunnel, the vehicles leading to the tunnel entrance are guided to reduce road congestion and avoid secondary traffic accidents in the tunnel.

[0139] The system modules are described as follows:

[0140] An information detection unit is installed in the monitored tunnel, for example, a video monitoring facility in the tunnel, and is used to detect and obtain a tunnel monitoring image of the overall monitoring area of ​​the tunnel in real time, and send it to the data processing unit in real time;

[0141] The data processing unit is installed in the monitoring center and includes an information processing module, a data transmission module, etc. It is used to analyze the tunnel monitoring image and identify whether a tunnel emergency occurs based on the current tunnel monitoring image; and when a tunnel emergency is identified, obtain a road traffic control decision L; according to the road traffic control decision L, control the advance warning unit 1, the variable speed limit unit 2, the electronic light curtain unit 3 and the light beam induction unit 4, and then actively and accurately intervene in the real-time traffic conditions of the tunnel during the handling of tunnel emergencies.

[0142] Advance warning unit 1: There are two advance warning units, namely: the first advance warning unit 1.1 and the second advance warning unit 1.2; each advance warning unit 1 includes a variable information board, a controller and a warning support frame; it is connected to the data processing unit, receives information instructions issued by the data processing unit, and is set about 1000m and 200m before the entrance of the accident-prone tunnel, respectively used to inform the tunnel section of the accident situation and vehicles entering the tunnel photoelectric guidance area to drive according to the guidance information.

[0143] Variable speed limit unit 2: There are two units, namely: the first variable speed limit unit 2.1 and the second variable speed limit unit 2.2; each variable speed limit unit 2 includes a variable speed limit display screen and a speed limit support frame; it is connected to the data processing unit, receives information instructions issued by the data processing unit, and is respectively arranged near the tunnel entrance and about 200m before the tunnel entrance. According to different system control modes and combined with the on-site road traffic flow conditions, it displays different speed limit information, such as 100, 80, 60, 40, X, etc.

[0144] In the direction from far to near the tunnel entrance, in front of the tunnel entrance, a first advance warning unit 1.1, a first variable speed limit unit 2.1, a second advance warning unit 1.2, a second variable speed limit unit 2.2 and an electronic light curtain unit 3 are arranged in sequence;

[0145] The electronic light curtain unit 3 includes a concentrated light beam 3.1, an aerosol spraying device 3.2 and a control device 3.3; it is connected to the data processing unit, receives information instructions issued by the data processing unit, is arranged in front of the tunnel entrance to avoid direct sunlight or mountain shadows, and uses light and shadow imaging technology to block and warn passing vehicles.

[0146] The beam induction unit 4 is arranged in the tunnel, including a projection device 4.1 and a ground projection beam arranged on the ground in the tunnel; it is connected to the data processing unit, receives information instructions issued by the data processing unit, and is arranged about 100-200m in the tunnel. By controlling the ground projection beam, it can actively guide or guide the lane level of passing vehicles. Among them, the ground projection beam includes 6 projection beam light strips and four projection induction arrow light strips, which are:

[0147] The first lane right-turn projection beam light strip A1 is arranged in the first lane; the second lane right-turn projection beam light strip A21 and the second lane left-turn projection beam light strip A22 are arranged in the second lane; the third lane left-turn projection beam light strip A3 is arranged in the third lane; the 1st-2nd middle section projection beam light strip A1-2 is arranged between the first lane and the second lane; the 2nd-3rd middle section projection beam light strip A2-3 is arranged between the second lane and the third lane;

[0148] The first lane right turn projection induction arrow light strip B1 is arranged in the first lane; the second lane right turn projection induction arrow light strip B21 and the second lane left turn projection induction arrow light strip B22 are arranged in the second lane; the third lane left turn projection induction arrow light strip B3 is arranged in the third lane.

[0149] The present invention is a method for active and precise intervention of traffic flow based on the vehicle operation status. It mainly intervenes in the tunnel section traffic according to tunnel emergencies, road traffic volume, and tunnel driving safety, and realizes the three functions of advance warning in front of the tunnel entrance, blocking the tunnel entrance, and active induction in the tunnel. In view of this, the two factors of vehicle operation safety in the tunnel and the degree of road traffic congestion are fully considered, and the road traffic flow after the tunnel emergency occurs is precisely intervened. The method is as follows:

[0150] Step S1, using the video monitoring facilities in the tunnel to monitor the entire monitoring area of ​​the tunnel in real time, and sending the tunnel monitoring images to the data processing unit in real time;

[0151] Step S2, the data processing unit analyzes the tunnel monitoring image in real time to determine whether a tunnel emergency occurs inside the tunnel; if so, further identifies the following tunnel emergency related information, including: the occurrence time T of the tunnel emergency, the occurrence location of the tunnel emergency inside the tunnel, the lane occupation of the tunnel emergency, and the event type Z of the tunnel emergency; wherein the lane occupation of the tunnel emergency includes whether each lane is occupied by the tunnel emergency, and the occupied area ratio of the occupied lane; the event type Z of the tunnel emergency includes safe passage events and unsafe passage events;

[0152] Step S3, the data processing unit estimates the time h required for handling the tunnel emergency according to the lane occupation of the tunnel emergency; according to the occurrence time T of the tunnel emergency and the time h required for handling the tunnel emergency, the road congestion degree estimation algorithm is used to estimate the road congestion degree P when the tunnel emergency is handled when no traffic intervention measures are adopted in the process of handling the tunnel emergency;

[0153] Step S4, the data processing unit obtains a road traffic control decision L according to the event type Z of the tunnel emergency, the road congestion level P, and the lane occupancy caused by the tunnel emergency;

[0154] Step S5: The data processing unit actively and accurately intervenes in the real-time traffic conditions of the tunnel according to the road traffic control decision L during the process of handling tunnel emergencies.

[0155] The following is a detailed description of each step:

[0156] Step S1, using the video monitoring facilities in the tunnel to monitor the entire monitoring area of ​​the tunnel in real time, and sending the tunnel monitoring images to the data processing unit in real time;

[0157] Step S2, the data processing unit analyzes the tunnel monitoring image in real time to determine whether a tunnel emergency occurs inside the tunnel; if so, further identifies the following tunnel emergency related information, including: the occurrence time T of the tunnel emergency, the occurrence location of the tunnel emergency inside the tunnel, the lane occupation of the tunnel emergency, and the event type Z of the tunnel emergency; wherein the lane occupation of the tunnel emergency includes whether each lane is occupied by the tunnel emergency, and the occupied area ratio of the occupied lane; the event type Z of the tunnel emergency includes safe passage events and unsafe passage events;

[0158] Step S2 is specifically as follows:

[0159] Step S2.1, the data processing unit reads that the number of lanes in the monitored tunnel is three, which are lane 1, lane 2 and lane 3 in the tunnel width direction;

[0160] The data processing unit identifies the lane lines in the tunnel monitoring image at the current monitoring time T, thereby performing image segmentation on the tunnel monitoring image to obtain a first lane area, a second lane area, and a third lane area;

[0161] Step S2.2, for the identified u-th lane area, u=1, 2, 3, the following method is used to determine whether a tunnel emergency occurs, whether the u-th lane area is occupied, and if it is occupied, determine the proportion of the occupied area of ​​the u-th lane area by the tunnel emergency:

[0162] Step S2.2.1, dividing the u-th lane area into M*N grids according to the preset grid side length;

[0163] For each grid (x m ,y n ), where x m and n are the row and column numbers of the grid, m = 1, 2, ..., M, n = 1, 2, ..., N, and the following method is used to identify whether it is abnormal at the current monitoring time T:

[0164] If the following formulas (1), (2) and (3) are satisfied at the same time, the grid (x m ,y n ) Conclusion of abnormality at the current monitoring time T:

[0165] |f T (x n ,y m )-f T-ΔT (x n ,y n )|≤Δf(1)

[0166] |f T (x n ,y n )-f T+ΔT (x n ,y n )|≤Δf(2)

[0167] |f T (x n ,y n )-f0(x n ,y n )|>Δf(3)

[0168] Where: f T (x n ,y n ) represents the grid (x m ,y n ) The image feature value at the current monitoring time T; f T-ΔT (x n ,y n ) represents the grid (x m ,y n ) The image feature value at the previous monitoring time T-ΔT; fT+ΔT (x n ,y n ) represents the grid (x m ,y n ) is the image feature value at the next monitoring time T+ΔT; ΔT is the time interval for acquiring tunnel monitoring images; Δf is the image feature recognition threshold; f0(x n ,y n ) represents the pre-stored grid (x m ,y n ) background image standard feature value, meaning: grid (x m ,y n ) when there are no vehicles or people on the road surface in the tunnel area;

[0169] Specifically, when formula (1) and formula (2) are established, it means that the grid (x m ,y n ) at the current monitoring time T, the difference between the image feature value at the previous monitoring time T-ΔT is small; at the same time, the difference between the image feature value at the next monitoring time T+ΔT is small, which means that the grid (x m ,y n ) is located in the tunnel area, and no moving object enters at the current monitoring time T; when formula (3) is established, it represents the grid (x m ,y n ) at the current monitoring time T, the image feature value is different from the standard feature value of the background image, which means that the grid (x m ,y n ) There are nearly stationary vehicles and people on the road surface of the tunnel area; therefore, when formula (1), formula (2) and formula (3) are all valid, the grid (x m ,y n ) The conclusion that a tunnel emergency occurs at the current monitoring time T, and the grid (x m ,y n ) Conclusion of abnormality at the current monitoring time T;

[0170] Step S2.2.2, at the current monitoring time T, in the first lane area, the second lane area, and the third lane area, as long as one abnormal grid is identified, it is concluded that a tunnel emergency occurs inside the tunnel;

[0171] For the u-th lane area, in its M*N grids, as long as one abnormal grid is identified, it is concluded that the tunnel emergency occupies the u-th lane; when the u-th lane is occupied by the tunnel emergency, the following formula is used to obtain the occupied area ratio Pr of the u-th lane by the tunnel emergency u :

[0172] Pru =Num u (abnormal) / M*N (4)

[0173] Where: Num u (abnormal) represents the number of abnormal grids in the u-th lane area at the current monitoring time T; M*N represents the total number of grids in the u-th lane area.

[0174] This step also includes: when a tunnel emergency event is identified to occur inside the tunnel, the following method is used to identify the event type Z of the tunnel emergency event:

[0175] Construct an emergency type library; in the emergency type library, determine the scope of safe passage events and the scope of unsafe passage events; match the identified tunnel emergency events with the emergency type library to determine the event type Z of the tunnel emergency event. Among them, according to the tunnel traffic safety after the tunnel emergency event occurs, tunnel emergencies are divided into two categories: one is safe passage events, such as vehicle rear-end collisions, scratches, and breakdowns, which have no impact on the passage of other vehicles in the tunnel; the other is unsafe passage events, such as tunnel vehicle fires, hazardous chemicals vehicle accidents, etc., which have an impact on the traffic safety of other vehicles in the tunnel.

[0176] The event type Z of tunnel emergencies is expressed as the following function:

[0177] Z=f(z)

[0178] Where: Z is the emergency type (Z = 0, 1), where 1 is a safe passage event and 0 is an unsafe passage event; f is the emergency type matching function, which is enumerated and matched by building an emergency type library.

[0179] Step S3, the data processing unit estimates the time h required for handling the tunnel emergency according to the lane occupancy caused by the tunnel emergency;

[0180] According to the occurrence time T of tunnel emergencies and the time h required for handling tunnel emergencies, the road congestion estimation algorithm is used to estimate the road congestion level P when the tunnel emergency is handled if no traffic intervention measures are taken during the handling of tunnel emergencies.

[0181] Specifically, in the present invention, the road traffic flow section flow is used as a factor for system intervention decision-making to minimize the road congestion caused by emergencies in the tunnel and ensure the passage of road vehicles. Based on this, in order to accurately estimate the road congestion level in the future period of the accident section (i.e., the period during the tunnel emergency handling process) and improve the scientificity and accuracy of the system intervention decision-making, the present invention constructs a dynamic estimation database of road section traffic volume based on the historical data information of the checkpoint before the tunnel entrance and the video monitoring in the tunnel.

[0182] Step S3 is specifically as follows:

[0183] Step S3.1: Estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] when no traffic intervention measures are adopted [T,T+h] ;

[0184] Step S3.1 is specifically as follows:

[0185] Step S3.1.1, establish a two-layer architecture database and update it dynamically in real time;

[0186] The two-layer database is based on an annual cycle and adopts a two-layer time series architecture. The first layer is the historical traffic data of the previous year; the second layer is the traffic data from the current year to the current moment, and the second layer is dynamically filled with time as the axis. When the traffic data of the current year is filled, it will be transferred to the first layer (the original traffic data of the first layer will be cleared), and the traffic data of the new year will continue to be filled in the second layer. When there is no data in the acquired time series, it will be skipped directly and continue to fill in the next time. For the traffic data of the previous year and the current year, the traffic data storage structure is the same, both of which are: the total traffic volume per day is stored in the data unit of the day; each data unit is divided into 24 data units with time as the axis, and each data unit is the traffic volume per hour. Thus, a database of daily and hourly traffic volume changes on the roads in the monitoring section is formed.

[0187] Specifically, in the two-layer database, the first layer is the traffic volume record information of the previous year, and the data record includes: the daily traffic volume of the previous year and the daily traffic volume growth coefficient; wherein the daily traffic volume of the previous year is expressed as traffic volume i=1,2,.....,365, represents the total traffic volume on the i-th day of the previous year; the daily traffic volume growth coefficient of the previous year is expressed as Represents the growth coefficient of the traffic volume on the i-th day of the previous year compared to the traffic volume on the i-1th day of the previous year, that is:

[0188] For traffic volume Further recorded is the hourly traffic volume and hourly traffic volume ratio of the i-th day of the previous year; among which, the hourly traffic volume of the i-th day of the previous year is expressed as j=1,2,.....,24, meaning: the j-th hourly traffic volume on the i-th day of the previous year; the hourly traffic volume ratio coefficient on the i-th day of the previous year is expressed as Meaning: the traffic volume in the jth hour on the i-th day of the previous year The traffic volume on the i-th day of the previous year proportion;

[0189] The next layer is the traffic volume record information for this year, which has the same structure as the data record of the previous year and is dynamically filled in by hour based on time axis;

[0190] Step S3.1.2, when the occurrence time T of the tunnel emergency is identified, the day D of the tunnel emergency occurrence time T in the current year is obtained, that is, the tunnel emergency occurs at the Tth hour of the Dth day of the current year; here, T is the time expressed in 24-hour format, and T is an integer hour or a non-integer hour, for example, T is 13 o'clock; or T is 13.5 hours;

[0191] Step S3.1.3, use formula (6) to estimate the traffic volume on the Dth day of the year

[0192]

[0193] in:

[0194] Represents the traffic volume on day D-1 of the current year;

[0195] Represents the traffic growth coefficient on the Dth day of the previous year;

[0196] represents the traffic growth coefficient of the i-th day of the year; represents the traffic growth coefficient of the i-th day of the previous year; The meaning is: the sum of the difference in traffic growth coefficients from day 1 to day D-1 in this year and the previous year;

[0197] Step S3.1.4, determine whether the tunnel emergency incident handling end time T+h and the tunnel emergency incident occurrence time T are on the same day, that is, determine whether the relationship T+h≤24 holds; if so, it indicates that they are on the same day, and execute step S3.1.5; otherwise, it indicates that they cross days, that is, the tunnel emergency incident handling end time T+h is on the D+1 day, and execute step S3.1.6;

[0198] Step S3.1.5, using formula (7), estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] [T,T+h] :

[0199]

[0200] in: represents the traffic volume at hour [T]-1 on day D of the current year; where [T] represents T rounded down to an integer;

[0201] Represents the sum of the traffic volume share coefficients from hour [T] to hour [T+h] on day D of the previous year; where [T+h] represents T+h rounded down to an integer;

[0202] Step S3.1.6, using formula (8), estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] [T,T+h] :

[0203]

[0204] in: Represents the estimated traffic volume from the time T when the tunnel emergency occurred to 24:00 on the D day of the current year; represents the traffic volume on the Dth day of the current year, specifically the total traffic volume on the Dth day of the current year; is the total traffic volume from hour 1 to hour [T] on day D of the current year, directly read from the database in step S3.1.1; represents the traffic volume from hour [T] to hour T on day D of the current year, directly read from the database in step S3.1.1;

[0205] Represents the estimated traffic volume from 0:00 to T+h-24 on the D+1 day of the current year; represents the traffic volume on day D of the previous year; Represents the total traffic volume from hour 1 to hour [T+h-24] on day D+1 of the previous year; Represents the traffic volume at hour [T+h-24+1] on day D+1 of the previous year; h-[h] represents the decimal part of the time h required to handle tunnel emergencies; [h] represents the integer rounded down; for example, [1.5]=1, [0.5]=0.

[0206] Step S3.2, using formula (5), obtain the road congestion level P when the tunnel emergency is handled:

[0207]

[0208] Where: m is the number of tunnel lanes; m lis the number of lanes occupied by tunnel emergencies; C is the tunnel design capacity, in pcu / line. For example, the number of tunnel lanes m = 3, which means there are three lanes in total; the number of lanes occupied by tunnel emergencies m l The values ​​can be: 0, 1, 2, 3, representing: the tunnel emergency does not occupy any lane, occupies 1 lane, occupies 2 lanes, occupies 3 lanes.

[0209] Step S4, the data processing unit obtains a road traffic control decision L according to the event type Z of the tunnel emergency, the road congestion level P, and the lane occupancy caused by the tunnel emergency;

[0210] Step S4 is specifically as follows:

[0211] Taking into account the needs of road traffic, minimizing the impact of emergencies in tunnels, combined with the estimated results of road traffic congestion, on the premise of ensuring road driving safety and alleviating road congestion, this system performs different control measurements for different types of emergencies.

[0212] Step S4.1: presetting a threshold δ of the road congestion level P P , taking the third level of road service level as the boundary, δ P Can be set to 0.75;

[0213] If the road congestion level P≤δ P , then the road traffic control decision L shown in formula (9) is executed; if the road congestion level P>δ P , then the road traffic control decision L shown in formula (10) is executed:

[0214]

[0215] Among them: u Represents the lane number occupied by the tunnel emergency; the monitored tunnel has three lanes, namely lane 1, lane 2 and lane 3; l u =1, 2, 3, representing that the tunnel emergency occupies lane 1, lane 2, and lane 3 respectively; l u =0, indicating that the tunnel emergency does not occupy any lane;

[0216] Z=0, representing the event type Z of the tunnel emergency event as an unsafe passage event;

[0217] Z = 1, representing that the event type Z of the tunnel emergency is a safe passage event;

[0218] Pr1, Pr2, and Pr3 represent the proportion of the occupied area of ​​lane 1, lane 2, and lane 3 by tunnel emergencies, respectively;

[0219] Pr0 represents the preset threshold value of the ratio of tunnel emergencies to lane occupancy area.

[0220] Step S5: The data processing unit actively and accurately intervenes in the real-time traffic conditions of the tunnel according to the road traffic control decision L during the process of handling tunnel emergencies.

[0221] Based on the above-mentioned road traffic decision results of vehicle operation safety and congestion degree, combined with the traffic flow precision intervention system based on electronic light curtain of the present invention, its decision instruction control strategy is as follows:

[0222] (I) Intervention methods when L = 0:

[0223] like Figure 4 As shown in the figure, when L = 0, it means that during the handling of tunnel emergencies, all lanes of the controlled tunnel are blocked. At this time:

[0224] Advance warning unit 1: The first advance warning unit 1.1 at the far end displays a warning message: "Accident ahead, slow down"; the second advance warning unit 1.2 at the near end displays a warning message: "Accident ahead, please stop";

[0225] Variable speed limit unit 2: the first variable speed limit unit 2.1 at the far end displays the speed limit as "40", and the second variable speed limit unit 2.2 at the near end displays the speed limit as "X";

[0226] Electronic light curtain unit 3: in working state, the light curtain displays the blocking information of "X stop X";

[0227] Beam guidance unit 4: All projection beam light strips are always on, preventing the vehicle from moving forward; all projection guidance arrow light strips are off;

[0228] (II) Intervention methods when L=1:

[0229] like Figure 5 As shown in the figure, when L=1, it means that during the tunnel emergency handling process, lane 1 can be safely used:

[0230] Advance warning unit 1: The first advance warning unit 1.1 at the far end displays a warning message: "Please slow down due to an accident ahead", and the second advance warning unit 1.2 at the near end displays a warning message: "Drive according to the guidance in the light and shadow guidance area";

[0231] Variable speed limit unit 2: the first variable speed limit unit 2.1 at the far end displays the speed limit as "60", and the second variable speed limit unit 2.2 at the near end displays the speed limit as "40";

[0232] Electronic light curtain unit 3: in the closed state;

[0233] Beam induction unit 4:

[0234] The left-turn projection beam light strip A22 in the second lane, the left-turn projection beam light strip A3 in the third lane, and the projection beam light strip A2-3 in the middle section between the second and third lanes are always on, preventing vehicles from passing through the second and third lanes;

[0235] The left-turn projection induction arrow light strip B22 in the second lane and the left-turn projection induction arrow light strip B3 in the third lane are in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0236] (III) Intervention methods when L=2:

[0237] like Figure 6 As shown in the figure, when L=2, it means that during the tunnel emergency handling process, the third lane can be safely used:

[0238] Advance warning unit 1: The first advance warning unit 1.1 at the far end displays a warning message: "Please slow down due to an accident ahead", and the second advance warning unit 1.2 at the near end displays a warning message: "Drive according to the guidance in the light and shadow guidance area";

[0239] Variable speed limit unit 2: the first variable speed limit unit 2.1 at the far end displays the speed limit as "60", and the second variable speed limit unit 2.2 at the near end displays the speed limit as "40";

[0240] Electronic light curtain unit 3: in the closed state;

[0241] Beam induction unit 4:

[0242] The right-turn projection beam light strip A1 in the first lane, the right-turn projection beam light strip A21 in the second lane, and the projection beam light strip A1-2 in the middle section between the first and second lanes are always on, preventing vehicles from passing through the first and second lanes;

[0243] The right-turn projection induction arrow light strip B1 in the first lane and the right-turn projection induction arrow light strip B21 in the second lane are in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0244] (IV) Intervention methods when L=3:

[0245] like Figure 7 As shown in the figure, when L=3, it means that during the tunnel emergency handling process, lanes 2 and 3 can be safely used:

[0246] Advance warning unit 1: The first advance warning unit 1.1 at the far end displays a warning message: "Please slow down due to an accident ahead", and the second advance warning unit 1.2 at the near end displays a warning message: "Drive according to the guidance in the light and shadow guidance area";

[0247] Variable speed limit unit 2: the first variable speed limit unit 2.1 at the far end displays the speed limit as "80", and the second variable speed limit unit 2.2 at the near end displays the speed limit as "60";

[0248] Electronic light curtain unit 3: in the closed state;

[0249] Beam induction unit 4:

[0250] The right-turn projection beam light strip A1 in lane 1 and the projection beam light strip A1-2 in the middle section of lane 1-2 are always on, preventing vehicles from passing through lane 1;

[0251] The right-turn projection induction arrow light strip B1 in lane 1 is in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0252] (V) Intervention methods when L=4:

[0253] like Figure 8 As shown in the figure, when L=4, it means that during the tunnel emergency handling process, lanes 1 and 2 can be safely used:

[0254] Advance warning unit 1: The first advance warning unit 1.1 at the far end displays a warning message: "Please slow down due to an accident ahead", and the second advance warning unit 1.2 at the near end displays a warning message: "Drive according to the guidance in the light and shadow guidance area";

[0255] Variable speed limit unit 2: the first variable speed limit unit 2.1 at the far end displays the speed limit as "80", and the second variable speed limit unit 2.2 at the near end displays the speed limit as "60";

[0256] Electronic light curtain unit 3: in the closed state;

[0257] Beam induction unit 4:

[0258] The left-turn projection beam light strip A3 in the 3rd lane and the projection beam light strip A2-3 in the middle section of the 2nd-3rd lane are always on, preventing vehicles from passing through the 3rd lane;

[0259] The left-turn projection induction arrow light strip B3 in the third lane is in the on-guiding state, and the other projection induction arrow light strips are in the off state;

[0260] (VI) Intervention methods when L=5:

[0261] like Fig. 9 As shown in the figure, when L=5, it means that no tunnel emergency occurs, and lanes 1, 2, and 3 are all safe to pass:

[0262] Advance warning unit 1: The first advance warning unit 1.1 at the far end displays a warning message: "Be careful in the tunnel ahead", and the second advance warning unit 1.2 at the near end displays a warning message: "Slow down in the light and shadow guidance area";

[0263] Variable speed limit unit 2: the first variable speed limit unit 2.1 at the far end displays the speed limit as "100", and the second variable speed limit unit 2.2 at the near end displays the speed limit as "80";

[0264] Electronic light curtain unit 3: in the closed state;

[0265] Beam induction unit 4:

[0266] The 1st-2nd middle section projection beam light strip A1-2 and the 2nd-3rd middle section projection beam light strip A2-3 are in a long-cycle flashing guidance state to prevent driving fatigue; all other projection beam light strips are in an off state;

[0267] All projection induction arrow light strips are turned off.

[0268] The present invention provides a system and method for precise intervention in traffic flow based on electronic light curtains, proposes an active and precise intervention method for traffic flow based on vehicle operation safety and congestion level, and uses electronic light curtain technology to achieve precise intervention in the operation status of road traffic flow; specifically, based on tunnel electromechanical facilities and integrating electronic light curtain technology, multi-mode precise intervention such as advance warning at the front of the tunnel entrance, blocking at the tunnel entrance, and active induction in the tunnel is achieved, which makes up for the limitations and practicality of a single control mode system and alleviates the road congestion pressure caused by tunnel traffic accidents.

[0269] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. A precise traffic flow intervention system based on electronic light curtain, characterized in that: include: A data processing unit, an information detection unit, an advance warning unit (1), a variable speed limit unit (2), an electronic light curtain unit (3) and a light beam induction unit (4); the data processing unit is connected to the information detection unit, the advance warning unit (1), the variable speed limit unit (2), the electronic light curtain unit (3) and the light beam induction unit (4) respectively; The information detection unit is installed in the monitored tunnel, and is used to detect and obtain the tunnel monitoring image of the entire monitoring area of ​​the tunnel in real time, and send it to the data processing unit in real time; The data processing unit is installed in the monitoring center and is used to analyze the tunnel monitoring image and identify whether a tunnel emergency occurs based on the current tunnel monitoring image; And when a tunnel emergency is identified, a road traffic control decision L is obtained; According to the road traffic control decision L, the advance warning unit (1), the variable speed limit unit (2), the electronic light curtain unit (3) and the light beam induction unit (4) are controlled, thereby actively and accurately intervening in the real-time traffic conditions of the tunnel during the handling of tunnel emergencies.

2. According to claim 1, a precise traffic flow intervention system based on an electronic light curtain is characterized in that: The number of the advance warning units (1) is two, namely: a first advance warning unit (1.1) and a second advance warning unit (1.2); the number of the variable speed limit units (2) is two, namely: a first variable speed limit unit (2.1) and a second variable speed limit unit (2.2); In the direction from far to near the tunnel entrance, a first advance warning unit (1.1), a first variable speed limit unit (2.1), a second advance warning unit (1.2), a second variable speed limit unit (2.2) and an electronic light curtain unit (3) are sequentially arranged in front of the tunnel entrance; Wherein: each of the advanced warning units (1) comprises a variable information board, a controller and a warning support frame; Each of the variable speed limit units (2) comprises a variable speed limit display screen and a speed limit support frame; The electronic light curtain unit (3) comprises a concentrated light beam (3.1), an aerosol spraying device (3.2) and a control device (3.3); and is used to implement blocking and warning of passing vehicles through light and shadow imaging technology; The light beam induction unit (4) is arranged in the tunnel, and comprises a projection device (4.1) and a ground projection light beam arranged on the ground in the tunnel; wherein the ground projection light beam comprises 6 projection beam light strips and four projection induction arrow light strips, which are respectively: The first lane right-turn projection beam light strip (A1) is arranged in the first lane; the second lane right-turn projection beam light strip (A21) and the second lane left-turn projection beam light strip (A22) are arranged in the second lane; the third lane left-turn projection beam light strip (A3) is arranged in the third lane; the 1st-2nd middle section projection beam light strip (A1-2) is arranged between the first lane and the second lane; the 2nd-3rd middle section projection beam light strip (A2-3) is arranged between the second lane and the third lane; The first lane right turn projection induction arrow light strip (B1) is arranged in the first lane; the second lane right turn projection induction arrow light strip (B21) and the second lane left turn projection induction arrow light strip (B22) are arranged in the second lane; the third lane left turn projection induction arrow light strip (B3) is arranged in the third lane.

3. A method of a traffic flow precision intervention system based on an electronic light curtain according to any one of claims 1-2, characterized in that: The following steps are involved: Step S1, using the video monitoring facilities in the tunnel to monitor the entire monitoring area of ​​the tunnel in real time, and sending the tunnel monitoring images to the data processing unit in real time; Step S2, the data processing unit analyzes the tunnel monitoring image in real time to determine whether a tunnel emergency occurs inside the tunnel; If it occurs, the following tunnel emergency related information is further identified, including: the occurrence time T of the tunnel emergency, the occurrence location of the tunnel emergency in the tunnel, the lane occupation of the tunnel emergency, and the event type Z of the tunnel emergency; wherein, the lane occupation of the tunnel emergency includes whether the tunnel emergency occupies each lane and the occupied area ratio of the occupied lane; the event type Z of the tunnel emergency includes safe passage events and unsafe passage events; Step S3, the data processing unit estimates the time h required for handling the tunnel emergency according to the lane occupation of the tunnel emergency; according to the occurrence time T of the tunnel emergency and the time h required for handling the tunnel emergency, the road congestion degree estimation algorithm is used to estimate the road congestion degree P when the tunnel emergency is handled when no traffic intervention measures are adopted in the process of handling the tunnel emergency; Step S4, the data processing unit obtains a road traffic control decision L according to the event type Z of the tunnel emergency, the road congestion level P, and the lane occupancy caused by the tunnel emergency; Step S5: The data processing unit actively and accurately intervenes in the real-time traffic conditions of the tunnel according to the road traffic control decision L during the process of handling tunnel emergencies.

4. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 3 is characterized in that: Step S2 is specifically as follows: Step S2.1, the data processing unit reads that the number of lanes in the monitored tunnel is three, which are lane 1, lane 2 and lane 3 in the tunnel width direction; The data processing unit identifies the lane lines in the tunnel monitoring image at the current monitoring time T, thereby performing image segmentation on the tunnel monitoring image to obtain a first lane area, a second lane area, and a third lane area; Step S2.2, for the identified u-th lane area, u=1, 2, 3, the following method is used to determine whether a tunnel emergency occurs, whether the u-th lane area is occupied, and if it is occupied, determine the proportion of the occupied area of ​​the u-th lane area by the tunnel emergency: Step S2.2.1, dividing the u-th lane area into M*N grids according to the preset grid side length; For each grid (x m ,y n ), where x m and n are the row and column numbers of the grid, m = 1, 2, ..., M, n = 1, 2, ..., N, and the following method is used to identify whether it is abnormal at the current monitoring time T: If the following formulas (1), (2) and (3) are satisfied at the same time, the grid (x m ,y n ) Conclusion of abnormality at the current monitoring time T: |f T (x n ,y n )-f T-ΔT (x n ,y n )|≤Δf (1) |f T (x n ,y n )-f T+ΔT (x n ,y n )|≤Δf (2) |f T (x n ,y n )-f0(x n ,y n )|>Δf (3) Where: f T (x n ,y n ) represents the grid (x m ,y n ) The image feature value at the current monitoring time T; f T-ΔT (x n ,y n ) represents the grid (x m ,y n ) The image feature value at the previous monitoring time T-ΔT; f T+ΔT (x n ,y n ) represents the grid (x m ,y n ) is the image feature value at the next monitoring time T+ΔT; ΔT is the time interval for acquiring tunnel monitoring images; Δf is the image feature recognition threshold; f0(x n ,y n ) represents the pre-stored grid (x m ,y n ) background image standard feature value, meaning: grid (x m ,y n ) when there are no vehicles or people on the road surface in the tunnel area; Specifically, when formula (1) and formula (2) are established, it means that the grid (x m ,y n ) at the current monitoring time T, the difference between the image feature value at the previous monitoring time T-ΔT is small; at the same time, the difference between the image feature value at the next monitoring time T+ΔT is small, which means that the grid (x m ,y n ) is located in the tunnel area, and no moving object enters at the current monitoring time T; when formula (3) is established, it represents the grid (x m ,y n ) at the current monitoring time T, the image feature value is different from the standard feature value of the background image, which means that the grid (x m ,y n ) There are nearly stationary vehicles and people on the road surface of the tunnel area; therefore, when formula (1), formula (2) and formula (3) are all valid, the grid (x m ,y n ) The conclusion that a tunnel emergency occurs at the current monitoring time T, and the grid (x m ,y n ) Conclusion of abnormality at the current monitoring time T; Step S2.2.2, at the current monitoring time T, in the first lane area, the second lane area, and the third lane area, as long as one abnormal grid is identified, it is concluded that a tunnel emergency occurs inside the tunnel; For the u-th lane area, in its M*N grids, as long as one abnormal grid is identified, it is concluded that the tunnel emergency occupies the u-th lane; when the u-th lane is occupied by the tunnel emergency, the following formula is used to obtain the occupied area ratio Pr of the u-th lane by the tunnel emergency u : Pr u =Num u (abnormal) / M*N (4) Where: Num u (abnormal) represents the number of abnormal grids in the u-th lane area at the current monitoring time T; M*N represents the total number of grids in the u-th lane area.

5. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 2, characterized in that: When a tunnel emergency event is identified inside the tunnel, the following method is used to identify the event type Z of the tunnel emergency event: Constructing an emergency event type library; in the emergency event type library, determining the scope of events that can be safely passed and the scope of events that cannot be safely passed; The identified tunnel emergency event is matched with the emergency event type library to determine the event type Z of the tunnel emergency event.

6. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 5, characterized in that: Events that allow safe passage include vehicle rear-end collisions, scratches, and breakdowns, which have no impact on the passage of other vehicles in the tunnel; events that are not safe to pass include tunnel vehicle fires and accidents involving vehicles carrying hazardous chemicals, which have an impact on the safety of other vehicles in the tunnel.

7. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 5, characterized in that: Step S3 is specifically as follows: Step S3.1: Estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] when no traffic intervention measures are adopted [T,T+h] ; Step S3.2, using formula (5), obtain the road congestion level P when the tunnel emergency is handled: Where: m is the number of tunnel lanes; m l is the number of lanes occupied by tunnel emergencies; C is the designed traffic capacity of the tunnel.

8. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 7, characterized in that: Step S3.1 is specifically as follows: Step S3.1.1, establish a two-layer architecture database and update it dynamically in real time; In the two-layer database, the first layer is the traffic volume record information of the previous year, and the data record includes: the daily traffic volume of the previous year and the daily traffic volume growth coefficient; wherein the daily traffic volume of the previous year is expressed as traffic volume represents the total traffic volume on the i-th day of the previous year; the daily traffic volume growth coefficient of the previous year is expressed as Represents the growth coefficient of the traffic volume on the i-th day of the previous year compared to the traffic volume on the i-1th day of the previous year; For traffic volume Further recorded is the hourly traffic volume and hourly traffic volume ratio of the i-th day of the previous year; among which, the hourly traffic volume of the i-th day of the previous year is expressed as Meaning: the j-th hourly traffic volume on the i-th day of the previous year; the hourly traffic volume ratio coefficient on the i-th day of the previous year is expressed as Meaning: the traffic volume in the jth hour on the i-th day of the previous year The traffic volume on the i-th day of the previous year proportion; The next layer is the traffic volume record information for this year, which has the same structure as the data record of the previous year and is dynamically filled in by hour based on time axis; Step S3.1.2, when the occurrence time T of the tunnel emergency event is identified, the day D of the occurrence time T of the tunnel emergency event in this year is obtained, that is, the tunnel emergency event occurs at the Tth hour of the Dth day of this year; here, T is the time expressed in 24-hour format, and T is an integer hour or a non-integer hour; Step S3.1.3, use formula (6) to estimate the traffic volume on the Dth day of the year in: Represents the traffic volume on day D-1 of the current year; Represents the traffic growth coefficient on the Dth day of the previous year; represents the traffic growth coefficient of the i-th day of the year; represents the traffic growth coefficient of the i-th day of the previous year; The meaning is: the sum of the differences in the daily traffic growth coefficients from day 1 to day D1 in this year and the previous year; Step S3.1.4, determine whether the tunnel emergency incident handling end time T+h and the tunnel emergency incident occurrence time T are on the same day, that is, determine whether the relationship T+h≤24 holds; if so, it indicates that they are on the same day, and execute step S3.1.5; otherwise, it indicates that they cross days, that is, the tunnel emergency incident handling end time T+h is on the D+1 day, and execute step S3.1.6; Step S3.1.5, using formula (7), estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] [T，T+h] : in: Represents the traffic volume at hour [T]-1 on day D of the current year; where [T] represents T rounded down to an integer: Represents the sum of the traffic volume share coefficients from hour [T] to hour [T+h] on day D of the previous year; where [T+h] represents T+h rounded down to an integer; Step S3.1.6, using formula (8), estimate the tunnel traffic volume Q in the tunnel emergency handling period [T, T+h] [T，T+h] : in: Represents the estimated traffic volume from the time T when the tunnel emergency occurred to 24:00 on the D day of the current year; represents the traffic volume on the Dth day of the current year, specifically the total traffic volume on the βth day of the current year; is the total traffic volume from hour 1 to hour [T] on day D of the current year, directly read from the database in step S3.1.1; represents the traffic volume from hour [T] to hour T on day D of the current year, directly read from the database in step S3.1.1; Represents the estimated traffic volume from 0:00 to T+h-24 on the D+1 day of the current year; represents the traffic volume on day D of the previous year; Represents the total traffic volume from hour 1 to hour [T+h-24] on day D+1 of the previous year: It represents the traffic volume at hour [T+h-24+1] on day D+1 of the previous year; h-[h] represents the decimal part of the time h required for handling tunnel emergencies; [h] represents the integer rounded down for h.

9. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 4, characterized in that: Step S4 is specifically as follows: Step S4.1: presetting a threshold δ of the road congestion level P P ; If the road congestion level P≤δ P , then the road traffic control decision L shown in formula (9) is executed; If the road congestion level P>δ P , then the road traffic control decision L shown in formula (10) is executed: Where: l u Represents the lane number occupied by the tunnel emergency; the monitored tunnel has three lanes, namely lane 1, lane 2 and lane 3; l u =1, 2, 3, representing that the tunnel emergency occupies lane 1, lane 2, and lane 3 respectively; l u =0, indicating that the tunnel emergency does not occupy any lane; Z=0, representing the event type Z of the tunnel emergency event as an unsafe passage event; Z = 1, representing that the event type Z of the tunnel emergency is a safe passage event; Pr1, Pr2 and Pr3 represent the proportion of the occupied area of ​​the first lane, the second lane and the third lane respectively due to tunnel emergencies: Pr0 represents the preset threshold value of the ratio of tunnel emergencies to lane occupancy area.

10. The method of a traffic flow precision intervention system based on an electronic light curtain according to claim 9, characterized in that: Step S5 is specifically as follows: (I) Intervention methods when L = 0: When L=0, it means that during the tunnel emergency handling process, all lanes of the controlled tunnel are blocked. At this time: Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message of "accident ahead, slow down"; the second advance warning unit (1.2) at the near end displays a warning message of "accident ahead, please stop"; Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "40", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "X"; Electronic light curtain unit (3): in working state, the light curtain displays the blocking information of "X stop X"; Beam guidance unit (4): all projection beam light strips are in a constant on state, preventing the vehicle from moving forward; all projection guidance arrow light strips are in an off state; (II) Intervention methods when L=1: When L=1, it means that during the tunnel emergency handling process, lane 1 is safe for traffic: Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message of "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message of "drive according to the guidance in the light and shadow guidance area"; Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "60", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "40"; Electronic light curtain unit (3): in a closed state; Beam induction unit (4): The left-turn projection beam light strip (A22) in the second lane, the left-turn projection beam light strip (A3) in the third lane, and the projection beam light strip between the second and third lanes (A2-3) are always on, preventing vehicles from passing through the second and third lanes; The left-turn projection induction arrow light strip (B22) in the second lane and the left-turn projection induction arrow light strip (B3) in the third lane are in the on-guiding state, and the other projection induction arrow light strips are in the off state; (III) Intervention methods when L=2: When L=2, it means that during the tunnel emergency handling process, lane 3 is safe for traffic: Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message of "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message of "drive according to the guidance in the light and shadow guidance area"; Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "60", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "40"; Electronic light curtain unit (3): in a closed state; Beam induction unit (4): The right-turn projection beam light strip (A1) in lane 1, the right-turn projection beam light strip (A21) in lane 2, and the projection beam light strip between lanes 1 and 2 (A1-2) are always on, preventing vehicles from passing through lanes 1 and 2; The right-turn projection induction arrow light strip (B1) in lane 1 and the right-turn projection induction arrow light strip (B21) in lane 2 are in the on-guiding state, and the other projection induction arrow light strips are in the off state; (IV) Intervention methods when L=3: When L=3, it means that during the tunnel emergency handling process, lanes 2 and 3 are safe for traffic: Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message of "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message of "drive according to the guidance in the light and shadow guidance area"; Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "80", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "60"; Electronic light curtain unit (3): in a closed state; Beam induction unit (4): The right-turn projection beam light strip (A1) in lane 1 and the projection beam light strip (A1-2) in the middle section of lane 1-2 are always on, preventing vehicles from passing through lane 1; The right-turn projection induction arrow light strip (B1) in lane 1 is in the on-guiding state, and the other projection induction arrow light strips are in the off state; (V) Intervention methods when L=4: When L=4, it means that during the tunnel emergency handling process, lanes 1 and 2 are safe for traffic: Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message of "accident ahead, please slow down", and the second advance warning unit (1.2) at the near end displays a warning message of "drive according to the guidance in the light and shadow guidance area"; Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "80", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "60"; Electronic light curtain unit (3): in a closed state; Beam induction unit (4): The left-turn projection beam light strip (A3) in lane 3 and the projection beam light strip (A2-3) in the middle section of lane 2-3 are always on, preventing vehicles from passing through lane 3; The left-turn projection guidance arrow light strip (B3) in lane 3 is in the on-guiding state, and the other projection guidance arrow light strips are in the off state; (VI) Intervention methods when L=5: When L=5, it means that no tunnel emergency occurs and lanes 1, 2, and 3 are all safe for traffic: Advance warning unit (1): the first advance warning unit (1.1) at the far end displays a warning message of "Be careful in the tunnel ahead", and the second advance warning unit (1.2) at the near end displays a warning message of "Slow down in the light and shadow guidance area". Variable speed limit unit (2): the first variable speed limit unit (2.1) at the far end displays the speed limit as "100", and the second variable speed limit unit (2.2) at the near end displays the speed limit as "80"; Electronic light curtain unit (3): in a closed state; Beam induction unit (4): The 1st-2nd middle projection beam light strip (A1-2) and the 2nd-3rd middle projection beam light strip (A2-3) are in a long-period flashing guidance state to prevent driving fatigue; all other projection beam light strips are in an off state; All projection induction arrow light strips are turned off.

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