Intersection overflow state identification method, system and device based on radar data, and medium

Abstract

The invention relates to an intersection overflow state recognition method, system and device based on radar data and a medium, and the method comprises the steps: obtaining the position information of an entrance stop line through radar software or a trajectory analysis radar, and introducing a map and / or trajectory analysis to calibrate the exit overflow detection range of each entrance of a target intersection; screening track points in an outlet overflow detection range to obtain a track point set; solving at least one state evaluation index based on the track point set; determining an outlet overflow state by comparing the state evaluation index with a preset state threshold value; and if it is determined that exit overflow occurs, determining existence and ending of an exit overflow event of the target intersection according to the collected continuous overflow times and continuous non-overflow times. According to the invention, through accurate space calibration, efficient data processing, scientific state evaluation and comprehensive event determination, the problem that the overflow identification capability of the existing radar trajectory technology in a complex and changeable urban traffic environment is limited is effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of intelligent transportation technology, and in particular to a method, system, device and medium for identifying intersection overflow status based on radar data. Background Art

[0002] In the field of intelligent traffic management, radar trajectory technology, as an important monitoring method, has been widely used in vehicle tracking, traffic flow monitoring and accident warning. This technology transmits electromagnetic waves through radar equipment and receives reflected signals to obtain information such as the distance, speed, angle, etc. of the target, and then construct the target's movement trajectory. The development of this technology provides traffic management departments with rich real-time data, which helps to improve road traffic efficiency and safety.

[0003] However, as the problem of urban traffic congestion becomes increasingly serious, the application of radar trajectory technology in overflow identification faces new challenges. Due to the complexity and variability of urban traffic networks, vehicles often seek alternative routes to avoid congestion points when encountering congestion or accidents. This behavior is called traffic overflow. Traditional radar trajectory technology mainly focuses on the monitoring of individual vehicles or specific road sections, and has limited overall identification and prediction capabilities for traffic overflow. Therefore, when traffic overflow occurs, management departments often find it difficult to quickly and accurately grasp the scope and impact of the overflow, resulting in delayed emergency response and further aggravating traffic congestion.

[0004] In addition, existing radar trajectory technology is also inefficient when processing large amounts of data. Due to the huge amount of urban traffic, radar equipment needs to continuously collect and process massive amounts of data, which places extremely high demands on data processing algorithms and computing resources. When processing speed is limited, it is difficult to achieve real-time identification and early warning of traffic overflow, which affects the efficiency and effectiveness of traffic management.

[0005] Therefore, although the existing radar trajectory technology provides strong support for traffic monitoring, it still has limitations in dealing with complex and changing traffic environments and accurately identifying traffic overflow. These limitations are mainly reflected in the lack of accuracy and stability of trajectory data, and the lack of effective overflow identification algorithms to timely and accurately judge the state of traffic overflow. These deficiencies not only affect the efficiency of traffic management, but may also lead to increased traffic congestion and waste of traffic resources. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a method, system, device and medium for identifying intersection overflow status based on radar data, which solves the technical problem that the existing radar trajectory technology has limited overflow identification capability and low data processing efficiency in complex and changeable urban traffic environments, making it difficult to judge the traffic overflow status in real time and accurately, thus affecting the efficiency and effectiveness of traffic management.

[0008] (II) Technical solution

[0009] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0010] In a first aspect, an embodiment of the present invention provides a method for identifying an intersection overflow state based on radar data, comprising:

[0011] The location information of the entrance stop line is obtained through radar software or trajectory analysis radar, and the exit overflow detection range of each entrance of the target intersection is calibrated by map and / or trajectory analysis;

[0012] Filter the trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set;

[0013] Based on the trajectory point set, obtaining a state evaluation index including at least one of the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency;

[0014] Determining an outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold;

[0015] If it is determined that an exit overflow occurs, the existence and end of the exit overflow event of the target intersection is determined based on the collected consecutive overflow times and consecutive non-overflow times.

[0016] Optionally, the location information of the import stop line is obtained by radar software or trajectory analysis radar, and the export overflow detection range of each import of the target intersection is calibrated by map and / or trajectory analysis, including:

[0017] Start the radar software or trajectory analysis radar to obtain the position information of the import stop line at a set frequency, wherein the position information includes the x value or the longitude and latitude coordinates of the stop line;

[0018] Receive and pre-process the position information of the import stop line obtained from the radar software or the trajectory analysis radar;

[0019] Using the pre-processed entrance parking line location information, call the high-precision map module, and spatially locate each entrance of the target intersection by matching the location information with map feature points to obtain the potential exit overflow detection range;

[0020] According to the defined potential overflow area, a continuous trajectory segment passing through the potential overflow area is filtered out from the collected vehicle trajectory data;

[0021] According to the timestamp and location information, the continuous trajectory segment is divided into independent trajectory segments, each of which represents the movement of the vehicle in a specific time period;

[0022] By comparing the distance and time difference between the consecutive position points of each independent trajectory segment, the instantaneous speed and acceleration of the vehicle at each point are obtained;

[0023] Based on the instantaneous speed, acceleration and location information of each point, identify whether vehicles form a queue in the potential overflow area;

[0024] Determine the starting and ending points of the queue, and calibrate the exit overflow detection range of each entrance of the target intersection based on the overlap range of the starting and ending points of the queue with the defined potential overflow area.

[0025] Optionally, the trajectory points within the outlet overflow detection range are filtered according to preset conditions, and the obtained trajectory point set includes:

[0026] For the original trajectory obtained, based on the set time range and detection radar information, the trajectory points detected by the specified radar within the set time period are preliminarily screened out;

[0027] For the initially screened trajectory points, the trajectory points belonging to the exit overflow detection range of the target intersection i entrance j are screened;

[0028] According to the changing trend of the x value within the exit overflow detection range of the target intersection i entrance j, the trajectory points belonging to the exit lane vehicles are identified;

[0029] Determine whether the number of trajectory points belonging to the exit lane vehicle is greater than or equal to 2;

[0030] If the number of trajectory points is less than 2, readjust the filtering conditions or expand the set time range until a sufficient number of trajectory points are found to obtain a trajectory point set.

[0031] Optionally, based on the trajectory point set, obtaining at least one of the state evaluation indicators including the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency includes:

[0032] For each trajectory in the trajectory point set, determine the first trajectory point, the last trajectory point and the corresponding timestamp of each trajectory;

[0033] Calculate the x-velocity of each trajectory based on the first trajectory point, the last trajectory point and the corresponding timestamps;

[0034] Calculate the average x-speed of all trajectories to obtain the average velocity of the trajectories within the detection range;

[0035] According to the x value, longitude coordinate or latitude coordinate of the stop line, a trajectory N1 passing through the stop line is selected from the trajectory point set;

[0036] According to the x speed of each trajectory and the number of exit lanes M of the corresponding road section, combined with the average length of the vehicle, the occupancy rate of the stop line is calculated;

[0037] Count the number of trajectory points N2 in the trajectory point set that are within the detection range;

[0038] According to the length z of the detection area and the number of exit lanes M of the corresponding road section, the theoretical maximum vehicle capacity within the detection range is calculated;

[0039] The average length of the vehicle and the number of trajectory points N2 located in the detection area are divided by the theoretical maximum vehicle capacity to obtain the space occupancy within the detection range;

[0040] The state evaluation index including at least one of the number of trajectory points within the detection range, the average velocity of the trajectory, and the time occupancy rate of the stop line is output at a set frequency.

[0041] Optionally,

[0042] The x velocity of the nth trajectory is:

[0043]

[0044] Where n∈(1,2,3...,N), is the coordinate of the last trajectory point, is the timestamp of the last trajectory point, is the coordinate of the first trajectory point, The timestamp of the first trajectory point:

[0045] The average trajectory speed is:

[0046]

[0047] Where N is the total number of vehicles within the detection range;

[0048] The occupancy rate of the parking line is:

[0049]

[0050] Where N1 is the number of vehicles whose trajectory passes the stop line, Δt is the set frequency, and M is the number of exit lanes;

[0051] The space occupancy is:

[0052]

[0053] Where L is the average length of the vehicle, N2 is the number of vehicles within the exit overflow detection range during this detection cycle, and z is the length of the detection area.

[0054] Optionally, determining the outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold includes:

[0055] Comparing at least one status assessment indicator with a corresponding preset status threshold;

[0056] According to the comparison result, if the actual values ​​of all state evaluation indicators are not less than the corresponding preset state thresholds, it is determined that the outlet is in an overflow state;

[0057] If the actual value of any state evaluation indicator is less than the corresponding preset state threshold, it is determined that the outlet is not in an overflow state.

[0058] Optionally, if it is determined that an exit overflow occurs, determining the existence and end of an exit overflow event at a target intersection according to the collected consecutive overflow times and consecutive non-overflow times includes:

[0059] A continuous overflow counter is set to record the number of times the target intersection exit is continuously detected as an exit overflow, and is initialized to 0;

[0060] If the detection result is an export overflow, the value of the continuous overflow counter is increased by 1;

[0061] If the value of the counter reaches the preset continuous overflow number threshold, it is determined that an exit overflow event occurs at the exit of the target intersection;

[0062] If the continuous overflow number threshold is not reached, the detection continues;

[0063] After determining that an outlet overflow event occurs, reset and start another continuous non-overflow counter to record the number of times the continuous detection result is that the outlet does not overflow, and initialize it to 0;

[0064] Continue to perform real-time detection on the exit lane of the target intersection, and judge each detection result according to the continuous non-overflow threshold;

[0065] If the detection result is still an export overflow, the export overflow event is determined, and the continuous non-overflow counter is reset to 0;

[0066] If the test result shows that the exit has not overflowed, the value of the continuous non-overflow counter is increased by 1;

[0067] If the value of the continuous non-overflow counter reaches a preset continuous non-overflow threshold, it is determined that the exit overflow event of the target intersection exit is over;

[0068] After the exit overflow event ends, the continuous non-overflow counter is reset and stopped, and the continuous overflow counter is restarted to monitor the next possible exit overflow event.

[0069] In a second aspect, an embodiment of the present invention provides a system for identifying an intersection overflow state based on radar data, comprising:

[0070] A detection range definition module is used to obtain the location information of the entrance stop line through radar software or trajectory analysis radar, and introduce a map and / or trajectory analysis to calibrate the exit overflow detection range of each entrance of the target intersection;

[0071] A trajectory screening module is used to screen trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set;

[0072] An index obtaining module, used to obtain, based on a set of trajectory points, a state evaluation index including at least one of the trajectory points within a detection range, an average trajectory speed, and a time occupancy rate of a stop line at a set frequency;

[0073] An overflow state judgment module, used to determine the outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold;

[0074] The overflow event judgment module is used to determine the existence and end of the exit overflow event of the target intersection based on the collected continuous overflow times and continuous non-overflow times if it is determined that the exit overflow occurs.

[0075] In a third aspect, an embodiment of the present invention provides a device for identifying an intersection overflow state based on radar data, including:

[0076] at least one database;

[0077] and a memory in communication with at least one database;

[0078] The memory stores instructions that can be executed by at least one database, and the instructions are executed by at least one database so that the at least one database can execute the intersection overflow state identification method based on radar data as described above.

[0079] In a fourth aspect, an embodiment of the present invention provides a computer-readable medium having computer executable instructions stored thereon, and when the executable instructions are executed by a processor, the method for identifying intersection overflow status based on radar data as described above is implemented.

[0080] (III) Beneficial effects

[0081] The beneficial effects of the present invention are:

[0082] First, the present invention accurately obtains the location information of the entrance stop line through radar software or trajectory analysis radar, and accurately calibrates the exit overflow detection range of each entrance of the target intersection in combination with map and / or trajectory analysis. This step can accurately calibrate the exit overflow detection range of each entrance of the target intersection, ensuring the pertinence of the recognition process, thereby improving the recognition accuracy and reliability in complex traffic environments.

[0083] Secondly, the present invention intelligently screens the trajectory points within the outlet overflow detection range under preset conditions to obtain a trajectory point set. This step effectively eliminates irrelevant data, improves the efficiency and accuracy of data processing, and lays a solid foundation for the subsequent calculation of state evaluation indicators.

[0084] Next, based on the selected trajectory point set, the present invention obtains at least one of the state evaluation indicators including the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency. These indicators can comprehensively and objectively reflect the traffic conditions at the intersection and provide a scientific basis for the judgment of the overflow state.

[0085] Then, the present invention can accurately determine the outlet overflow state by comparing the calculated state evaluation index with the preset state threshold. This comparison mechanism makes the judgment of the overflow state more intuitive and reliable, and effectively avoids the occurrence of misjudgment and missed judgment.

[0086] Furthermore, after determining that an exit overflow has occurred, the present invention determines the existence and end of an exit overflow event at the target intersection based on the collected continuous overflow times and continuous non-overflow times. This determination mechanism not only considers the instantaneous state of the overflow, but also combines the duration and change trend of the overflow, making the understanding of the overflow event more comprehensive and in-depth.

[0087] Therefore, the present invention effectively solves the problem of limited overflow identification ability of existing radar trajectory technology in complex and changeable urban traffic environments through precise spatial calibration, efficient data processing, scientific status assessment and comprehensive event judgment. It not only improves the efficiency and effectiveness of traffic management, but also significantly enhances the real-time and accurate judgment capability of traffic overflow status in complex and changeable urban traffic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 A schematic flow chart of a method for identifying an intersection overflow state based on radar data is provided for an embodiment of the present invention;

[0089] Figure 2 A specific flow chart of step S1 of a method for identifying an intersection overflow state based on radar data is provided for an embodiment of the present invention;

[0090] Figure 3A schematic diagram of the calibration range of a method for identifying an intersection overflow state based on radar data is provided for an embodiment of the invention;

[0091] Figure 4 A specific flow chart of step S2 of a method for identifying an intersection overflow state based on radar data is provided for an embodiment of the invention;

[0092] Figure 5 A specific flow chart of step S3 of a method for identifying overflow state of an intersection based on radar data is provided for an embodiment of the invention;

[0093] Figure 6 A specific flow chart of step S4 of a method for identifying an intersection overflow state based on radar data is provided for an embodiment of the invention;

[0094] Figure 7 A specific flow chart of step S5 of a method for identifying an intersection overflow state based on radar data is provided for an embodiment of the invention;

[0095] Figure 8 An overall flow chart of a method for identifying intersection overflow status based on radar data is provided for an embodiment of the invention. DETAILED DESCRIPTION

[0096] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0097] like Figure 1 As shown, an intersection overflow state identification method based on radar data proposed in an embodiment of the present invention includes: obtaining the position information of the import stop line through radar software or trajectory analysis radar, and introducing a map and / or trajectory analysis to calibrate the exit overflow detection range of each import of the target intersection; screening the trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set; based on the trajectory point set, obtaining a state evaluation index including at least one of the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency; determining the exit overflow state by comparing at least one state evaluation index with a preset state threshold; if it is determined that the exit overflow occurs, determining the existence and end of the exit overflow event of the target intersection according to the collected continuous overflow times and continuous non-overflow times.

[0098] First, the present invention accurately obtains the location information of the entrance stop line through radar software or trajectory analysis radar, and accurately calibrates the exit overflow detection range of each entrance of the target intersection in combination with map and / or trajectory analysis. This step can accurately calibrate the exit overflow detection range of each entrance of the target intersection, ensuring the pertinence of the recognition process, thereby improving the recognition accuracy and reliability in complex traffic environments.

[0099] Secondly, the present invention intelligently screens the trajectory points within the outlet overflow detection range under preset conditions to obtain a trajectory point set. This step effectively eliminates irrelevant data, improves the efficiency and accuracy of data processing, and lays a solid foundation for the subsequent calculation of state evaluation indicators.

[0100] Next, based on the selected trajectory point set, the present invention obtains at least one of the state evaluation indicators including the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency. These indicators can comprehensively and objectively reflect the traffic conditions at the intersection and provide a scientific basis for the judgment of the overflow state.

[0101] Then, the present invention can accurately determine the outlet overflow state by comparing the calculated state evaluation index with the preset state threshold. This comparison mechanism makes the judgment of the overflow state more intuitive and reliable, and effectively avoids the occurrence of misjudgment and missed judgment.

[0102] Furthermore, after determining that an exit overflow has occurred, the present invention determines the existence and end of an exit overflow event at the target intersection based on the collected continuous overflow times and continuous non-overflow times. This determination mechanism not only considers the instantaneous state of the overflow, but also combines the duration and change trend of the overflow, making the understanding of the overflow event more comprehensive and in-depth.

[0103] Therefore, the present invention effectively solves the problem of limited overflow identification ability of existing radar trajectory technology in complex and changeable urban traffic environments through precise spatial calibration, efficient data processing, scientific status assessment and comprehensive event judgment. It not only improves the efficiency and effectiveness of traffic management, but also significantly enhances the real-time and accurate judgment capability of traffic overflow status in complex and changeable urban traffic environments.

[0104] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0105] Specifically, an embodiment of the present invention provides a method for identifying an intersection overflow state based on radar data, comprising:

[0106] S1. Obtain the location information of the import stop line through radar software or trajectory analysis radar, and introduce map and / or trajectory analysis to calibrate the export overflow detection range of each import of the target intersection.

[0107] Furthermore, if Figure 2As shown, step S1 includes:

[0108] S11, start the radar software or trajectory analysis radar to obtain the position information of the import stop line at a set frequency Δt, wherein the position information includes the x value or the longitude and latitude coordinates of the stop line.

[0109] S12, receiving and preprocessing the position information of the import stop line obtained from the radar software or the trajectory analysis radar.

[0110] S13. Using the pre-processed location information of the entrance parking line, call the high-precision map module, and spatially locate each entrance of the target intersection by matching the location information with map feature points to obtain a potential exit overflow detection range.

[0111] S14. According to the defined potential overflow area, continuous trajectory segments passing through the potential overflow area are screened out from the collected vehicle trajectory data.

[0112] S15. Segment the continuous trajectory segment into independent trajectory segments according to the timestamp and the location information, each independent trajectory segment represents the movement of the vehicle in a specific time period.

[0113] S16. By comparing the distance and time difference between the continuous position points of each independent trajectory segment, the instantaneous speed and acceleration of the vehicle at each point are obtained.

[0114] S17. Based on the instantaneous speed, acceleration and location information of each point, identify whether the vehicles form a queue in the potential overflow area. Queuing behavior is usually manifested by a significant reduction in vehicle speed or even long-term stagnation.

[0115] S18. Determine the starting and ending points of the queue, and calibrate the exit overflow detection range of each entrance of the target intersection based on the overlap range of the starting and ending points of the queue with the defined potential overflow area. The calibration process involves drawing polygons on the map, setting virtual detection lines, or defining specific spatial areas. It is necessary to ensure that the calibrated range is neither too wide, resulting in invalid detection, nor too narrow, so as not to miss real overflow events. The calibrated range data is stored in digital form to facilitate subsequent automated processing and analysis.

[0116] Therefore, in this embodiment, according to the radar software or trajectory analysis radar, the x value (position coordinate in the horizontal direction) of the entrance stop line is detected, or the longitude and latitude of the road section stop line is used, and the high-precision map / trajectory analysis is used to calibrate the exit overflow detection range of each entrance of the target intersection. The calibration range is as follows: Figure 3This calibration process not only improves the ability to monitor traffic conditions, but also provides strong data support for subsequent traffic management and optimization. Through this method, it is possible to respond to events such as traffic overflow more quickly and accurately, thereby effectively improving the safety and efficiency of road traffic.

[0117] S2. Filter the trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set.

[0118] Furthermore, if Figure 4 As shown, step S2 includes:

[0119] S21. For the original trajectory obtained, based on the set time range and the detection radar information, preliminarily screen out the trajectory points monitored by the designated radar within the set time period.

[0120] S22. For the initially screened trajectory points, select the trajectory points that are within the overflow detection range of the exit of the target intersection i at the entrance j.

[0121] S23, identifying the trajectory points of the vehicle belonging to the exit lane according to the change trend of the x value within the exit overflow detection range of the entrance j of the target intersection i.

[0122] S24. Determine whether the number of trajectory points belonging to the exit lane vehicle is greater than or equal to 2.

[0123] S25. If the number of trajectory points is less than 2, readjust the screening conditions or expand the set time range until a sufficient number of trajectory points are found to obtain a trajectory point set.

[0124] Specifically, the trajectory points that meet the requirements within the detection range are screened (screened in the original trajectory table t_radar_position). The trajectory points that need to be screened within the detection range must meet the following conditions:

[0125] (2) Detection radar (entrance_Id) is the radar that monitors the entrance.

[0126] (3) Within the set time period [t, t+Δt].

[0127] (4) The trajectory point is within the overflow detection range of the exit road of the target intersection i entrance j.

[0128] (5) The trajectory is the trajectory of the exit lane vehicle (judged based on the x-values ​​of the trajectory points; vehicles with non-decreasing x-values ​​are exit lane vehicles).

[0129] (6) For the selected target vehicle IDobj_id, the number of trajectory points that meet the above conditions must be at least greater than or equal to 2.

[0130] S3. Based on the trajectory point set, obtain at least one state evaluation index including trajectory points within the detection range, average trajectory speed, and time occupancy rate of the stop line at a set frequency.

[0131] Furthermore, if Figure 5 As shown, step S3 includes:

[0132] S31. For each track in the track point set, determine the first track point, the last track point and the corresponding timestamp of each track.

[0133] S32, calculating the x speed of each trajectory according to the first trajectory point, the last trajectory point and the corresponding timestamp.

[0134] S33, calculating the average x-speed of all trajectories to obtain the average velocity of the trajectories within the detection range.

[0135] S34, selecting a trajectory N1 passing through the stop line from the trajectory point set according to the x value, longitude coordinate or latitude coordinate of the stop line.

[0136] S35. Calculate the occupancy rate of the stop line based on the x speed of each trajectory and the number of exit lanes M of the corresponding road section, combined with the average length of the vehicle.

[0137] S36, counting the number N2 of trajectory points in the trajectory point set that are within the detection range.

[0138] S37. Calculate the theoretical maximum vehicle capacity within the detection range according to the length z of the detection area and the number M of exit lanes of the corresponding road section.

[0139] It should be made clear that when calculating the spatial occupancy, each lane can be regarded as a basic width unit. Because in practical applications, although the lane width has a certain range (such as 3m-3.75m), when calculating the spatial occupancy, we are more concerned about whether the lane can be occupied by a vehicle rather than the exact width of the lane. Therefore, when the total spatial capacity is calculated by multiplying the length z of the detection area by the number of lanes M, the width information is actually implied. Each lane is regarded as a spatial unit that can accommodate a vehicle, and the number of lanes M represents the "number of units" in the width direction of the detection area. When calculating the spatial occupancy, if the detection area consists of multiple lanes and each lane can only accommodate one vehicle, the total spatial capacity of the detection area can be obtained by multiplying the length z of the detection area by the number of lanes M.

[0140] S38. Divide the average length of the vehicle and the number of trajectory points N2 within the detection area by the theoretical maximum vehicle capacity to obtain the space occupancy within the detection range.

[0141] S39, outputting at a set frequency a status evaluation index including at least one of the number of trajectory points within the detection range, the average trajectory speed, and the stop line time occupancy rate.

[0142] In a specific embodiment, the average velocity of the trajectory within the detection range is first calculated:

[0143] Assume that the set of trajectory points obtained in this screening is A, and there are N different obj_ids. For all obj_ids, calculate their x speed through the first and last trajectory points in the set:

[0144]

[0145] Where n∈(1,2,3...,N), is the coordinate of the last trajectory point, is the timestamp of the last trajectory point, is the coordinate of the first trajectory point, The timestamp of the first track point.

[0146] Next, calculate the average trajectory speed within the exit detection range during this detection cycle:

[0147]

[0148] Where N is the total number of vehicles within the detection range.

[0149] Secondly, according to the x value of the stop line (or the longitude / latitude coordinates of the stop line of the road section), the number of lanes M of the exit road of the road section, all the trajectories passing through the stop line in the trajectory point set A are selected. Assume that there are N1 trajectories with obj_id passing through the stop line, and the average length of the vehicle is L (the default is 7m). The speed of the target trajectory can be calculated as v n , then the occupancy rate of the parking line in the detection cycle is calculated as:

[0150]

[0151] Where N1 is the number of vehicles whose trajectory passes the stop line, Δt is the set frequency, and M is the number of exit lanes.

[0152] Furthermore, because the number of obj_ids of the trajectory points in the trajectory point set A is the number of vehicles N2 within the overflow detection range of the exit during this detection cycle, the spatial occupancy within the detection range is;

[0153]

[0154] Where L is the average length of the vehicle, N2 is the number of vehicles within the exit overflow detection range during this detection cycle, and z is the length of the detection area.

[0155] S4. Determine the outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold.

[0156] Furthermore, if Figure 6 As shown, step S4 includes:

[0157] S41. Compare at least one status evaluation indicator with a corresponding preset status threshold.

[0158] S42. According to the comparison result, if the actual values ​​of all the state evaluation indicators are not less than the corresponding preset state thresholds, it is determined that the outlet is in an overflow state.

[0159] S43. If the actual value of any state evaluation indicator is less than the corresponding preset state threshold, it is determined that the outlet is not in an overflow state.

[0160] Specifically, the result of this detection is judged according to the set speed threshold V1, time occupancy threshold P1, and space occupancy threshold D1: if the space occupancy D≥D1 within the detection range and the average trajectory speed V≤V1 within the detection range and the time occupancy P≥P1 of the stop line, then the result of this detection is judged as exit overflow; otherwise, the result is judged as no exit overflow.

[0161] S5. If it is determined that an exit overflow occurs, determine the existence and end of an exit overflow event at the target intersection based on the collected consecutive overflow times and consecutive non-overflow times.

[0162] Furthermore, if Figure 7 As shown, step S5 includes:

[0163] S51. Set a continuous overflow counter to record the number of times the exit of the target intersection is continuously detected as an exit overflow, and initialize it to 0.

[0164] S52: If the detection result is an export overflow, the value of the continuous overflow counter is increased by 1.

[0165] S53. If the value of the counter reaches a preset continuous overflow times threshold, it is determined that an exit overflow event occurs at the exit of the target intersection; if the value of the counter does not reach the continuous overflow times threshold K1, the detection is continued.

[0166] S54, after determining that an outlet overflow event occurs, reset and start another continuous non-overflow counter, which is used to record the number of times that the continuous detection result is that the outlet does not overflow, and is initialized to 0.

[0167] S55, continue to perform real-time detection on the target intersection exit, and determine each detection result according to the continuous non-overflow threshold.

[0168] S56: If the detection result is still an outlet overflow, the determination of the outlet overflow event is maintained, and the continuous non-overflow counter is reset to 0.

[0169] S57. If the detection result shows that the exit has not overflowed, the value of the continuous non-overflow counter is increased by 1.

[0170] S58. If the value of the continuous non-overflow counter reaches a preset continuous non-overflow times threshold value K2, it is determined that the exit overflow event of the target intersection exit is ended.

[0171] S59: After the export overflow event ends, reset and stop using the continuous non-overflow counter, and restart using the continuous overflow counter to monitor the next possible export overflow event.

[0172] Through the above sub-steps, it is possible to accurately determine whether an exit overflow event occurs at the exit of the target intersection, as well as the start and end of the event based on the continuous detection results, thereby providing timely and effective decision support for traffic management and control.

[0173] In addition, the present invention provides a system for identifying intersection overflow status based on radar data, comprising:

[0174] The detection range definition module is used to obtain the position information of the import stop line through radar software or trajectory analysis radar, and introduce map and / or trajectory analysis to calibrate the export overflow detection range of each import of the target intersection.

[0175] The trajectory screening module is used to screen the trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set.

[0176] The index obtaining module is used to obtain, based on the trajectory point set, a state evaluation index including at least one of the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency.

[0177] The overflow state judgment module is used to determine the outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold.

[0178] The overflow event judgment module is used to determine the existence and end of the exit overflow event of the target intersection based on the collected continuous overflow times and continuous non-overflow times if it is determined that the exit overflow occurs.

[0179] Furthermore, an embodiment of the present invention provides a device for identifying an intersection overflow state based on radar data, comprising: at least one database; and a memory communicatively connected to the at least one database; wherein the memory stores instructions executable by the at least one database, and the instructions are executed by the at least one database so that the at least one database can execute the method for identifying an intersection overflow state based on radar data as described above.

[0180] The embodiment of the present invention provides a device for identifying overflow status of intersections based on radar data, which is intended to identify and prevent potential overflow situations through radar trajectory data. The device mainly includes two core components: at least one database and a memory connected to the database.

[0181] As a data processing and storage center, the database is responsible for receiving, storing and analyzing radar trajectory data. It has powerful data processing capabilities and can efficiently analyze a large amount of radar trajectory data, thereby accurately identifying possible overflow situations.

[0182] The memory stores instructions that can be executed by the database. When these instructions are executed by the database, the database can execute a specific intersection overflow state identification method based on radar data. This method uses radar trajectory data for in-depth analysis and identification, aiming to timely detect and prevent potential overflow risks.

[0183] In short, this radar data-based intersection overflow status identification device achieves accurate identification and prevention of overflow situations through its efficient database and precise instruction set, further improving the safety and efficiency of related applications.

[0184] Furthermore, an embodiment of the present invention provides a computer-readable medium having computer-executable instructions stored thereon, and when the executable instructions are executed by a processor, the above-mentioned intersection overflow state identification method based on radar data is implemented.

[0185] The embodiment of the present invention also introduces a computer-readable medium, which is a physical storage medium, such as a hard disk, a flash drive, an optical disk, or any other medium capable of storing data. The medium stores computer-executable instructions, which are specifically designed for executing the intersection overflow state recognition method based on radar data.

[0186] When these computer executable instructions are read and executed by the execution environment of a computer or processor, they trigger a series of operations that implement the previously described intersection overflow state identification method based on radar data. This means that any computer system with an appropriate processor, as long as it can read the instructions on this computer readable medium, can perform the overflow identification task without the need for additional software installation or configuration.

[0187] In short, this computer-readable medium provides a convenient way to deploy and execute the radar data-based intersection overflow state identification method, so that the method can be flexibly applied to various computing environments, whether it is a fixed-installation system or a portable device.

[0188] In summary, the embodiments of the present invention provide a method, system, device and medium for identifying an intersection overflow state based on radar data. Figure 8 , we can see that the overall process is as follows:

[0189] First, the detection frequency needs to be set and the stop line value needs to be determined. By using radar software or trajectory analysis, the exit overflow detection range of each entrance of the target intersection can be calibrated.

[0190] Next, you need to filter the track points within the monitoring range. The filtering conditions for this step include: ensuring that the detection radar corresponds to the radar monitoring the entrance, the track point must be within the set time period, and located within the exit overflow detection range of the target intersection entrance. In addition, it is also necessary to determine whether it is the trajectory of the exit vehicle based on the value of the track point, and the number of track points that meet the above conditions must be at least greater than or equal to 2.

[0191] Next, the average speed of the trajectory within the detection range is calculated. The trajectory point set A is obtained by screening, and for each trajectory point, its speed is calculated through its first and last trajectory points in the set, and finally the average speed of the trajectory within the detection range of the exit channel in the detection cycle is obtained.

[0192] Then, the time occupancy of the stop line is calculated. This step requires filtering all the trajectories that pass through the stop line in the trajectory point set A according to the value of the stop line and the number of exit lanes. The occupancy of the stop line in the detection cycle can be calculated by setting the average length of the vehicle and the calculated speed of the target trajectory.

[0193] Then, the spatial occupancy rate in the detection area will be calculated. The spatial occupancy rate can be obtained by counting the number of trajectory points in set A, that is, the number of vehicles within the exit overflow detection range during this detection cycle, and combining it with the length of the detection area.

[0194] Furthermore, whether the result of this detection is an exit overflow will be determined based on the preset speed threshold, time occupancy threshold, and space occupancy threshold.

[0195] Finally, it is determined whether an outlet overflow event has occurred based on the continuous detection results. If the exit channel has multiple consecutive detection results showing an outlet overflow, it is determined that an outlet overflow event has occurred in the exit channel; and if the exit channel has multiple consecutive detection results showing no outlet overflow after the exit overflow event has occurred, it is determined that the exit overflow event has ended.

[0196] Based on real-time radar trajectory data, the exit lane and vehicle speed, number, occupancy rate and other indicators within the intersection are detected at a set frequency, and traffic events such as intersection exit lane overflow and intersection knots are identified in real time.

[0197] It should be made clear that the speed, number of vehicles, and occupancy threshold values ​​at each intersection are determined by the situation of the intersection itself, traffic conditions, and traffic volume, and require calibration by algorithms or on-site personnel based on experience or data.

[0198] Therefore, the present invention adopts a method based on real-time radar trajectory data to detect indicators such as vehicle speed, number and occupancy rate within the exit lane and intersection range at a set frequency, which has a significant beneficial effect on real-time identification of traffic events such as intersection exit lane overflow and intersection tangling.

[0199] Since the system / device described in the above embodiments of the present invention is a system / device used to implement the method of the above embodiments of the present invention, a person skilled in the art can understand the specific structure and deformation of the system / device based on the method described in the above embodiments of the present invention, and thus will not be described in detail here. All systems / devices used in the method of the above embodiments of the present invention belong to the scope of protection of the present invention.

[0200] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0201] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0202] It should be noted that in the claims, any reference numerals placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third, etc., is for convenience of expression only and does not indicate any order. These words may be understood as part of the component name.

[0203] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0204] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after knowing the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0205] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include these modifications and variations.

Claims

1. A method for identifying intersection overflow status based on radar data, characterized in that: include: The location information of the entrance stop line is obtained through radar software or trajectory analysis radar, and the exit overflow detection range of each entrance of the target intersection is calibrated by map and / or trajectory analysis; Filter the trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set; Based on the trajectory point set, obtaining a state evaluation index including at least one of the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency; Determining the outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold; If it is determined that an exit overflow occurs, the existence and end of the exit overflow event of the target intersection is determined based on the collected consecutive overflow times and consecutive non-overflow times.

2. The method for identifying intersection overflow status based on radar data as claimed in claim 1, characterized in that: The location information of the import stop line is obtained through radar software or trajectory analysis radar, and the export overflow detection range of each import of the target intersection is calibrated by map and / or trajectory analysis, including: Start the radar software or trajectory analysis radar to obtain the position information of the import stop line at a set frequency, wherein the position information includes the x value or the longitude and latitude coordinates of the stop line; Receive and pre-process the position information of the import stop line obtained from the radar software or the trajectory analysis radar; Using the pre-processed entrance parking line location information, call the high-precision map module, and spatially locate each entrance of the target intersection by matching the location information with map feature points to obtain the potential exit overflow detection range; According to the defined potential overflow area, a continuous trajectory segment passing through the potential overflow area is filtered out from the collected vehicle trajectory data; According to the timestamp and location information, the continuous trajectory segment is divided into independent trajectory segments, each of which represents the movement of the vehicle in a specific time period; By comparing the distance and time difference between the consecutive position points of each independent trajectory segment, the instantaneous speed and acceleration of the vehicle at each point are obtained; Based on the instantaneous speed, acceleration and location information of each point, identify whether vehicles form a queue in the potential overflow area; Determine the starting and ending points of the queue, and calibrate the exit overflow detection range of each entrance of the target intersection based on the overlap range of the starting and ending points of the queue with the defined potential overflow area.

3. The method for identifying intersection overflow status based on radar data as claimed in claim 1, characterized in that: The trajectory points within the exit overflow detection range are filtered according to the preset conditions, and the obtained trajectory point set includes: For the original trajectory obtained, based on the set time range and detection radar information, the trajectory points detected by the specified radar within the set time period are preliminarily screened out; For the initially screened trajectory points, the trajectory points belonging to the exit overflow detection range of the target intersection i entrance j are screened; According to the changing trend of the x value within the exit overflow detection range of the target intersection i entrance j, the trajectory points belonging to the exit lane vehicles are identified; Determine whether the number of trajectory points belonging to the exit lane vehicle is greater than or equal to 2; If the number of trajectory points is less than 2, readjust the filtering conditions or expand the set time range until a sufficient number of trajectory points are found to obtain a trajectory point set.

4. The method for identifying intersection overflow status based on radar data as claimed in claim 1, characterized in that: Based on the trajectory point set, obtaining at least one of the trajectory points within the detection range, the average trajectory speed, and the time occupancy rate of the stop line at a set frequency includes: For each trajectory in the trajectory point set, determine the first trajectory point, the last trajectory point and the corresponding timestamp of each trajectory; Calculate the x-velocity of each trajectory based on the first trajectory point, the last trajectory point and the corresponding timestamps; Calculate the average x-speed of all trajectories to obtain the average velocity of the trajectories within the detection range; According to the x value, longitude coordinate or latitude coordinate of the stop line, a trajectory N1 passing through the stop line is selected from the trajectory point set; According to the x speed of each trajectory and the number of exit lanes M of the corresponding road section, combined with the average length of the vehicle, the occupancy rate of the stop line is calculated; Count the number of trajectory points N2 in the trajectory point set that are within the detection range; According to the length z of the detection area and the number of exit lanes M of the corresponding road section, the theoretical maximum vehicle capacity within the detection range is calculated; The average length of the vehicle and the number of trajectory points N2 located in the detection area are divided by the theoretical maximum vehicle capacity to obtain the space occupancy within the detection range; The state evaluation index including at least one of the number of trajectory points within the detection range, the average trajectory speed, and the stop line time occupancy rate is output at a set frequency.

5. The method for identifying intersection overflow status based on radar data as claimed in claim 4, characterized in that: The x velocity of the nth trajectory is: Where n∈(1,2,3...,N), is the coordinate of the last trajectory point, is the timestamp of the last trajectory point, is the coordinate of the first trajectory point, The timestamp of the first trajectory point: The average trajectory speed is: Where N is the total number of vehicles within the detection range; The occupancy rate of the parking line is: Where N1 is the number of vehicles whose trajectory passes the stop line, Δt is the set frequency, and M is the number of exit lanes; The space occupancy is: Where L is the average length of the vehicle, N2 is the number of vehicles within the exit overflow detection range during this detection cycle, and z is the length of the detection area.

6. The method for identifying intersection overflow status based on radar data as claimed in claim 1, characterized in that: By comparing at least one status evaluation indicator with a preset status threshold, determining the export overflow status includes: Comparing at least one status assessment indicator with a corresponding preset status threshold; According to the comparison result, if the actual values ​​of all state evaluation indicators are not less than the corresponding preset state thresholds, it is determined that the outlet is in an overflow state; If the actual value of any state evaluation indicator is less than the corresponding preset state threshold, it is determined that the outlet is not in an overflow state.

7. The method for identifying intersection overflow status based on radar data as claimed in claim 1, characterized in that: If it is determined that an exit overflow occurs, the existence and end of the exit overflow event at the target intersection is determined based on the collected continuous overflow times and continuous non-overflow times, including: A continuous overflow counter is set to record the number of times the exit of the target intersection is continuously detected as an exit overflow, and is initialized to 0; If the detection result is an export overflow, the value of the continuous overflow counter is increased by 1; If the value of the counter reaches the preset continuous overflow number threshold, it is determined that an exit overflow event occurs at the exit of the target intersection; If the continuous overflow times threshold is not reached, the detection continues; After determining that an export overflow event occurs, reset and start another continuous non-overflow counter to record the number of times the continuous detection result is that the export does not overflow, and initialize it to 0; Continue to perform real-time detection on the exit lane of the target intersection, and judge each detection result according to the continuous non-overflow threshold; If the detection result is still an export overflow, the export overflow event is determined, and the continuous non-overflow counter is reset to 0; If the test result shows that the exit has not overflowed, the value of the continuous non-overflow counter is increased by 1; If the value of the continuous non-overflow counter reaches a preset continuous non-overflow threshold, it is determined that the exit overflow event of the target intersection exit is over; After the exit overflow event ends, the continuous non-overflow counter is reset and stopped, and the continuous overflow counter is restarted to monitor the next possible exit overflow event.

8. A system for identifying intersection overflow status based on radar data, characterized in that: include: A detection range definition module is used to obtain the location information of the entrance stop line through radar software or trajectory analysis radar, and introduce a map and / or trajectory analysis to calibrate the exit overflow detection range of each entrance of the target intersection; A trajectory screening module is used to screen trajectory points within the exit overflow detection range according to preset conditions to obtain a trajectory point set; An index obtaining module, used to obtain, based on a set of trajectory points, a state evaluation index including at least one of the trajectory points within a detection range, an average trajectory speed, and a time occupancy rate of a stop line at a set frequency; An overflow state judgment module, used to determine the outlet overflow state by comparing at least one state evaluation indicator with a preset state threshold; The overflow event judgment module is used to determine the existence and end of the exit overflow event of the target intersection based on the collected continuous overflow times and continuous non-overflow times if it is determined that the exit overflow occurs.

9. A device for identifying intersection overflow status based on radar data, characterized in that: include: at least one database; and a memory in communication with at least one database; The memory stores instructions that can be executed by at least one database, and the instructions are executed by at least one database so that the at least one database can execute the intersection overflow state identification method based on radar data as described in any one of claims 1-7.

10. A computer-readable medium having computer-executable instructions stored thereon, characterized in that: When the executable instructions are executed by the processor, the method for identifying intersection overflow status based on radar data as described in any one of claims 1 to 7 is implemented.

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