Method and device for determining ramp flow of ramp and machine-readable storage medium

Abstract

The present application discloses a method for determining the ramp flow of a ramp, the method comprising: obtaining first vehicle information of floating vehicles in a preset target road section; for any preset target ramp, performing the following: determining the first number of floating vehicles based on the position information, wherein the first number of floating vehicles is the number of floating vehicles at the preset target ramp; obtaining second vehicle information and the second number of floating vehicles of vehicles at at least one detection position, wherein the second vehicle information at least includes the main road flow; for any detection position, determining the permeability of floating vehicles based on the main road flow and the second number of floating vehicles; and determining the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position. Thereby, the ramp flow of the ramp is determined, and the accuracy of the determined ramp flow is improved.

Description

Technical Field

[0001] The present application relates to the field of traffic technology, and more specifically, to a method and device for determining ramp flow of a ramp, and a machine-readable storage medium. Background Art

[0002] In terms of the collection and acquisition of traffic data on expressway entrance and exit ramps, due to the high installation and maintenance costs of road detectors, many urban expressways rarely install road detectors on the ramps. Therefore, it is generally impossible to directly collect ramp traffic data.

[0003] In the prior art, the flow estimator is generally trained on the road section with complete ramp detector data, and the flow estimator is used to estimate the target road section with missing ramp detector data. However, this method does not consider the difference in traffic state distribution between the training road section and the target road section. Therefore, the estimated flow error is large. Summary of the invention

[0004] In view of this, the present application proposes a method and device for determining the ramp flow of a ramp and a machine-readable storage medium to improve the accuracy of determining the ramp flow.

[0005] In a first aspect, an embodiment of the present application provides a method for determining the ramp flow of a ramp, the method comprising: obtaining first vehicle information of a floating vehicle in a preset target section, wherein the preset target section at least includes at least an upstream section and a downstream section of at least one preset target ramp, and the first vehicle information at least includes position information; for a preset target ramp, the upstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and an upstream boundary of the preset target ramp, the downstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and a downstream boundary of the preset target ramp, the upstream boundary is a boundary of the upstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or a boundary of the preset target section that is closest to the preset target ramp, and the downstream boundary is a boundary of the downstream ramp of the preset target ramp in a corresponding area of ​​the preset target section. domain or the preset target road section that is closest to the preset target ramp; for any of the preset target ramps, perform the following: based on the position information, determine a first number of floating vehicles, wherein the first number of floating vehicles is the number of floating vehicles at the preset target ramp; obtain second vehicle information and a second number of floating vehicles of vehicles at at least one detection position, wherein the second vehicle information at least includes the main road flow, the second number of floating vehicles at any of the detection positions is the number of floating vehicles at the detection position, and the at least one detection position is located between the upstream boundary and the downstream boundary; for any of the detection positions, determine the permeability of the floating vehicles based on the main road flow and the second number of floating vehicles; and determine the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position.

[0006] Optionally, for any of the preset target ramps, based on the position information, determining the first number of floating vehicles includes: determining a first set and a second set based on the position information, wherein the first set is the set of floating vehicles included in the upstream section, and the second set is the set of floating vehicles included in the downstream section; and determining the first number of floating vehicles based on the first set and the second set.

[0007] Optionally, based on the position information, determining the first set and the second set includes: comparing the position information with the boundary position information of the upstream section to determine the floating vehicle in the upstream section to determine the first set; and comparing the position information with the boundary position information of the downstream section to determine the floating vehicle in the downstream section to determine the second set.

[0008] Optionally, the preset target road section includes an ascending main road and a descending main road, and the first vehicle information also includes an azimuth. Before determining the first number of floating vehicles based on the position information for any of the preset target ramps, the method further includes: determining the first vehicle information belonging to the ascending main road and the first vehicle information belonging to the descending main road based on the azimuth; wherein, for any of the preset target ramps, determining the first number of floating vehicles based on the position information includes determining the first number of floating vehicles based on the position information in the first vehicle information belonging to the main road connected to the preset target ramp.

[0009] Optionally, before determining the penetration rate of the floating vehicle for any of the preset target ramps and for any of the detection positions based on the main road flow and the second number of floating vehicles, the method further includes: preprocessing the acquired second vehicle information, wherein the preprocessing includes at least one of the following: repairing missing data, deleting erroneous data, and deleting abnormal combination data.

[0010] In a second aspect, an embodiment of the present application further provides a device for determining the ramp flow of a ramp, the device comprising: a first vehicle information acquisition module, used to acquire first vehicle information of a floating vehicle in a preset target section, wherein the preset target section at least includes at least one upstream section and a downstream section of a preset target ramp, and the first vehicle information at least includes location information; for a preset target ramp, the upstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and an upstream boundary of the preset target ramp, the downstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and a downstream boundary of the preset target ramp, the upstream boundary is a boundary of the upstream ramp of the preset target ramp in the corresponding area of ​​the preset target section or the preset target section that is closest to the preset target ramp, and the downstream boundary is a boundary of the downstream ramp of the preset target ramp in the opposite area of ​​the preset target section. a ramp flow determination module, for performing the following steps for any of the preset target ramps: determining a first number of floating vehicles based on the position information, wherein the first number of floating vehicles is the number of floating vehicles at the preset target ramp; obtaining second vehicle information and a second number of floating vehicles of vehicles at at least one detection position, wherein the second vehicle information at least includes a main road flow, the second number of floating vehicles at any of the detection positions is the number of floating vehicles at the detection position, and the at least one detection position is located between the upstream boundary and the downstream boundary; determining a permeability of the floating vehicles for any of the detection positions based on the main road flow and the second number of floating vehicles; and determining the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position.

[0011] Optionally, for any of the preset target ramps, based on the position information, determining the first number of floating vehicles includes: determining a first set and a second set based on the position information, wherein the first set is the set of floating vehicles included in the upstream section, and the second set is the set of floating vehicles included in the downstream section; and determining the first number of floating vehicles based on the first set and the second set.

[0012] Optionally, based on the position information, determining the first set and the second set includes: comparing the position information with the boundary position information of the upstream section to determine the floating vehicle in the upstream section to determine the first set; and comparing the position information with the boundary position information of the downstream section to determine the floating vehicle in the downstream section to determine the second set.

[0013] Optionally, the preset target road section includes an ascending main road and a descending main road, and the first vehicle information also includes an azimuth. Before determining the first number of floating vehicles based on the position information for any of the preset target ramps, the method further includes: determining the first vehicle information belonging to the ascending main road and the first vehicle information belonging to the descending main road based on the azimuth; wherein, for any of the preset target ramps, determining the first number of floating vehicles based on the position information includes determining the first number of floating vehicles based on the position information in the first vehicle information belonging to the main road connected to the preset target ramp.

[0014] In a third aspect, an embodiment of the present application further provides a machine-readable storage medium, on which instructions are stored, and when the instructions are executed by a processor, the processor is configured to execute the steps according to the above method.

[0015] According to the technical solution of the present application, the position information of the floating car in the preset target section is obtained, wherein the preset target section includes at least an upstream section and a downstream section of at least one preset target ramp, for any preset target ramp, the first number of floating cars is determined based on the position information, the penetration rate of the floating car is determined based on the main road flow and the second number of floating cars, and the ramp flow is determined based on the first number of floating cars and the penetration rate, so that the ramp flow of the ramp is determined. In addition, when determining the ramp flow of the ramp, based on the preset target section including the upstream section and the downstream section of the preset target ramp, the ramp flow of the preset target ramp can be determined relatively directly without the need for the training section, and the determined ramp flow can more accurately reflect the ramp flow of the preset target ramp, avoiding the error caused by the difference in traffic state distribution between the training section and the target section, and improving the accuracy of the determined ramp flow. In addition, when determining the ramp flow of the ramp, there is no need to use manual on-site investigation, which reduces labor costs and reduces danger. In addition, according to the technical solution of the present application, the ramp flow rate can be determined for any preset target ramp in at least one preset target ramp. When at least one preset target ramp includes multiple preset target ramps, the ramp flow rates of multiple preset target ramps can be determined simultaneously, so that the technical solution of the present application can be applied to the situation of obtaining the ramp flow rates of multiple ramps in real time, thereby expanding the scope of application. In addition, in the technical solution provided in the embodiment of the present application, location information, main road flow rate, etc. can be obtained in real time, and the acquisition is relatively easy and the cost is low. In this way, the real-time determination of ramp flow rate is achieved and the cost is reduced.

[0016] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present application, and the schematic implementation modes and descriptions of the present application are used to explain the present application. In the accompanying drawings:

[0018] Figure 1 is a flow chart of a method for determining a ramp flow rate of a ramp provided by an embodiment of the present application;

[0019] Figure 2 is a schematic diagram of a partial structure of a preset target road section provided in another embodiment of the present application; and

[0020] Figure 3 It is a structural block diagram of a device for determining the ramp flow of a ramp provided by another embodiment of the present application. DETAILED DESCRIPTION

[0021] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with the implementation modes.

[0022] In a first aspect, an embodiment of the present application provides a method for determining a ramp flow rate of a ramp.

[0023] Figure 1 FIG. 1 is a flow chart of a method for determining ramp flow of a ramp provided by an embodiment of the present application. Figure 1 As shown, the method includes the following contents.

[0024] In step S10, the first vehicle information of the floating vehicle in the preset target section is obtained, wherein the preset target section includes at least an upstream section and a downstream section of at least one preset target ramp. The first vehicle information includes at least position information. Optionally, in an embodiment of the present application, the position information may be coordinate information, for example, longitude and latitude information. In addition, in an embodiment of the present application, the floating vehicle may be a high-frequency floating vehicle. In addition, the technical solution provided in the embodiment of the present application may be applicable to various roads, for example, urban expressways, trunk roads, secondary trunk roads, etc., as long as there are main roads and ramps merging into the main roads. Optionally, in an embodiment of the present application, the position information may be obtained through a GPS positioning system.

[0025] For a preset target ramp, the upstream section is the section of the preset target ramp between the corresponding area of ​​the preset target section and the upstream boundary of the preset target ramp, and the downstream section is the section of the preset target ramp between the corresponding area of ​​the preset target section and the downstream boundary of the preset target ramp. For a preset target ramp, the upstream boundary is the upstream ramp of the preset target ramp in the corresponding area of ​​the preset target section or the boundary of the preset target section closest to the preset target ramp. Wherein, in the case where the upstream boundary is the upstream ramp of the preset target ramp in the corresponding area of ​​the preset target section, the upstream boundary can be the boundary of the upstream ramp in the corresponding area of ​​the preset target section close to the preset target ramp. For a preset target ramp, the downstream boundary is the downstream ramp of the preset target ramp in the corresponding area of ​​the preset target section or the boundary of the preset target section closest to the preset target ramp. Wherein, in the case where the downstream boundary is the downstream ramp of the preset target ramp in the corresponding area of ​​the preset target section, the downstream boundary can be the boundary of the downstream ramp in the corresponding area of ​​the preset target section close to the preset target ramp. It should be noted that, for any preset target ramp, if the preset target ramp has an upstream ramp, the upstream boundary is the corresponding area of ​​the upstream ramp of the preset target ramp in the preset target section; if the preset target ramp does not have an upstream ramp, the upstream boundary is the boundary of the preset target section that is closest to the preset target ramp. Similarly, for any preset target ramp, if the preset target ramp has a downstream ramp, the downstream boundary is the corresponding area of ​​the downstream ramp of the preset target ramp in the preset target section; if the preset target ramp does not have a downstream ramp, the downstream boundary is the boundary of the preset target section that is closest to the preset target ramp.

[0026] In the embodiment of the present application, the preset target ramp may be an entrance ramp or an exit ramp, and at least one preset target ramp may include an entrance ramp and / or an exit ramp.

[0027] In addition, in an embodiment of the present application, the preset target section may include a section with a unidirectional traffic flow direction, or may include a section with a bidirectional traffic flow direction. In the case where the preset target section includes a section with a bidirectional traffic flow direction, at least one preset target ramp may be distributed only on one side of the preset target section, or may be distributed on both sides of the preset target section. In the case where at least one preset target ramp is distributed on one side of the preset target section, the preset target section may include, in addition to the upstream section and downstream section of the at least one preset target ramp, an opposite section relative to the upstream section and downstream section of the at least one preset target ramp.

[0028] Assume that the preset target road section is from the XX1 bridge to the XX2 bridge, and includes a road section with a bidirectional traffic flow direction, wherein at least one preset target ramp is distributed on one side of the preset target road section. Figure 2Only a part of the preset target section is shown, that is, the section consisting of the upstream section and the downstream section of at least one preset target ramp. Figure 2 As shown, the XX1 bridge and the XX2 bridge are the boundaries of the preset target section. Some sections include the first section between the XX1 bridge and the first entrance ramp (the first entrance ramp has no upstream ramp and the XX1 bridge is closest to the first entrance ramp), the second section between the first entrance ramp and the second entrance ramp, the third section between the second entrance ramp and the third entrance ramp, the fourth section between the third entrance ramp and the exit ramp, and the fifth section between the exit ramp and the XX2 bridge (the exit ramp has no downstream ramp and the XX2 bridge is closest to the exit ramp). Based on the traffic flow direction, the downstream ramp of the first entrance ramp is the second entrance ramp; the upstream ramp of the second entrance ramp is the first entrance ramp, and the downstream ramp of the second entrance ramp is the third entrance ramp; the upstream ramp of the third entrance ramp is the second entrance ramp, and the downstream ramp of the third entrance ramp is the exit ramp; the upstream ramp of the exit ramp is the third entrance ramp. Based on the traffic flow direction, the upstream section and downstream section of the first entrance ramp are the first section and the second section respectively, the upstream section and downstream section of the second entrance ramp are the second section and the third section respectively, the upstream section and downstream section of the third entrance ramp are the third section and the fourth section respectively, and the upstream section and downstream section of the exit ramp are the fourth section and the fifth section respectively. The first corresponding area is the corresponding area of ​​the first entrance ramp in the preset target section, the second corresponding area is the corresponding area of ​​the second entrance ramp in the preset target section, the third corresponding area is the corresponding area of ​​the third entrance ramp in the preset target section, and the fourth corresponding area is the corresponding area of ​​the exit ramp in the preset target section.

[0029] In step S11, for any preset target ramp, the ramp flow is determined. Specifically, for any preset target ramp, the following contents are performed.

[0030] Based on the position information, a first number of floating vehicles is determined, wherein the first number of floating vehicles is the number of floating vehicles at the preset target ramp. Specifically, the set of floating vehicles located at the upstream section and the set of floating vehicles located at the downstream section may be determined according to the position information of the floating vehicles, and the number of floating vehicles of the floating vehicles at the preset target ramp may be determined according to the set of floating vehicles located at the upstream section and the set of floating vehicles located at the downstream section.

[0031] Obtain the second vehicle information and the second number of floating vehicles of the vehicle at at least one detection position, wherein the second vehicle information at least includes the main road flow, the second number of floating vehicles at any detection position is the number of floating vehicles at the detection position, and at least one detection position is located between the upstream boundary and the downstream boundary. It should be noted that in the embodiment of the present application, the main road is the road where the ramp merges, and the main road flow is the total flow of vehicles on the main road. Optionally, in the embodiment of the present application, a fixed detector may be set at the detection position, and the main road flow is obtained through the fixed detector. The fixed detector may be a microwave vehicle detector or a toroidal coil detector.

[0032] Optionally, in an embodiment of the present application, for any detection position, the second number of floating vehicles may be the number of floating vehicles within the range including the detection position, wherein the demarcation of the range including the inspection position may be determined according to the specific circumstances. In addition, for any detection position, the number of floating vehicles within the range including the detection position may be determined by referring to the method for determining the first set or determining the second set in the embodiment of the present application. Optionally, in an embodiment of the present application, for any detection position, the second number of floating vehicles is the number of floating vehicles in the upstream section or downstream section where the detection position is located. When the detection position is in the upstream section, the second number of floating vehicles is the number of floating vehicles in the upstream section; when the detection position is in the downstream section, the second number of floating vehicles is the number of floating vehicles in the downstream section. In other words, for any detection position, the second number of floating vehicles is the number of floating vehicles in the first set or the second set corresponding to the detection position.

[0033] For any detection position, the floating vehicle penetration rate is determined based on the main road flow and the second floating vehicle number. Specifically, for any detection position, the second floating vehicle number is divided by the main road flow to obtain the floating vehicle penetration rate.

[0034] The ramp flow of the preset target ramp is determined based on the first floating vehicle quantity and the permeability corresponding to at least one of the at least one detection position.

[0035] In the case that at least one detection position includes only one detection position, the ramp flow of the preset target ramp can be obtained by dividing the number of first floating vehicles by the permeability corresponding to the detection position.

[0036] In the case where at least one inspection position includes multiple detection positions, the following situations may be included. The ramp flow of the preset target ramp may be determined by using the permeability corresponding to the detection position closest to the preset target ramp in at least one detection position. Specifically, the ramp flow of the preset target ramp may be obtained by dividing the number of first floating vehicles by the permeability corresponding to the closest detection position. Alternatively, the ramp flow of the preset target ramp may be determined by using the permeability corresponding to the preset value detection positions close to the preset target ramp in at least one detection position, wherein the preset value may be determined according to the specific situation. For example, the permeability corresponding to the preset value detection positions is averaged, and the ramp flow is determined based on the average value obtained and the number of first floating vehicles. Specifically, the ramp flow of the preset target ramp may be obtained by dividing the number of first floating vehicles by the average value. Alternatively, the ramp flow of the preset target ramp may be determined by using the permeability corresponding to multiple detection positions. For example, the permeability corresponding to multiple detection positions is averaged, and the permeability is determined based on the average value obtained. Specifically, the ramp flow of the preset target ramp may be obtained by dividing the number of first floating vehicles by the average value.

[0037] In the embodiment of the present application, the number of floating vehicles on each preset target ramp can be determined. However, floating vehicles only account for a part of the vehicle composition on the road, and the collection of floating vehicles is a non-representative subset of all vehicles on the road, and it cannot represent the overall traffic volume of the road. However, the overall traffic volume of the road can be inferred based on the penetration rate of floating vehicles in all vehicles.

[0038] Specifically, a detection location can be set on the main road, and a fixed detector can be set at the detection location. The fixed detector can obtain the main road traffic at the detection location. For any detection location, the full time series data of the number of floating vehicles and the main road traffic can be obtained, which can be used to obtain the penetration rate of floating vehicles at the detection location.

[0039] Assume that the set of detection positions is L = {L 1 ,L 2 ,L 3 …L i …L m}, a fixed detector is set at each detection position. At any detection position, the main road traffic volume counted at a preset time interval is obtained. The preset time interval can be determined according to the specific situation. For example, the preset time interval can be 5 minutes. In the following introduction, the preset time interval of 5 minutes is used as an example for illustrative description. The data set of the main road traffic volume collected by the fixed detector at the detection position i is expressed as<N"(i,t),t> , where N"(i,t) is the main road traffic volume detected by the fixed detector at the detection position i within 5 minutes. Similarly, for the detection position i, the floating vehicle trajectory data can be aggregated in units of 5 minutes, and the trajectory dataset is marked as <N p "(i,t),t>, where N p "(i,t) is the number of second floating vehicles at detection position i. On the road, the total number of floating vehicles is a subset of the total number of vehicles on the road. Therefore, for detection position i, there are always N p "(i,t)≤N"(i,t) holds.

[0040] For any detection position i, the penetration rate of floating vehicles The penetration rate is defined as the ratio of the number of floating vehicles passing through the road at time t to the main road traffic.

[0041] Optionally, in the embodiment of the present application, for any preset target ramp, determining the first number of floating vehicles based on the location information may include the following contents: Based on the location information, determining a first set and a second set, wherein the first set is a set of floating vehicles included in the upstream section, and the second set is a set of floating vehicles included in the downstream section. Based on the first set and the second set, determining the first number of floating vehicles.

[0042] Specifically, based on the first set and the second set, combined with the traffic flow direction, the first floating vehicle number is determined. For example, the first floating vehicle number is obtained using the complement screening method. Using the closed nature of the road, in the same traffic flow direction, the traffic flow downstream of the road is only related to the traffic flow upstream of the main line of the road and the upstream entrance and exit ramps, and has nothing to do with other factors. Using this feature, the traffic flow can be estimated by the principle of mathematical intersection and complement. For the entrance ramp, the vehicle set Q of the entrance ramp 入 is the complement of the intersection of the vehicle set of the downstream section and the vehicle set of the upstream section in the vehicle set of the downstream section; for the exit ramp, the vehicle set Q of the exit ramp 出 is the complement of the intersection of the vehicle set of the upstream segment and the vehicle set of the downstream segment in the vehicle set of the upstream segment. Therefore, the on-ramp and off-ramp flows can be expressed as: Q 入 =Q 下游 -(Q 上游 ∩Q下游 );Q 出 =Q 上游 -(Q 上游 ∩Q 下游 ). Among them, Q 上游 is the set of vehicles on the upstream section, Q 下游 is the vehicle set of the downstream section. Then, for the entrance ramp, the first number of floating vehicles is the number of floating vehicles included in the complement of the floating vehicle set of the downstream section by the intersection of the floating vehicle set of the downstream section and the floating vehicle set of the upstream section; for the exit ramp, the first number of floating vehicles is the number of floating vehicles included in the complement of the floating vehicle set of the upstream section by the intersection of the floating vehicle set of the downstream section and the floating vehicle set of the upstream section.

[0043] by Figure 2 Taking the first entrance ramp, the second entrance ramp, the third entrance ramp and the exit ramp in the example, how to determine the number of floating vehicles is exemplified. Assume that the sets of floating vehicles in the first section, the second section, the third section, the fourth section and the fifth section are A, B, C, D and E respectively. For the first entrance ramp, the first set is A, the second set is B, and the number of floating vehicles is N. 入1 =B-(B∩A). For the second entrance ramp, the first set is B, the second set is C, and the number of floating cars is N 入2 =C-(B∩C). For the third entrance ramp, the first set is C, the second set is D, and the number of floating cars is N 入3 =D-(C∩D). For the exit ramp, the first set is D, the second set is E, and the number of floating cars is N 出 =D-(D∩E).

[0044] Optionally, in an embodiment of the present application, determining the first set and the second set based on the location information may include the following contents.

[0045] The position information is compared with the boundary position information of the upstream section to determine the floating vehicles in the upstream section to determine the first set. The position information is compared with the boundary position information of the downstream section to determine the floating vehicles in the downstream section to determine the second set.

[0046] According to the above analysis, for any preset target ramp, the upstream section is the section between the corresponding area of ​​the preset target ramp in the preset target section and the upstream boundary of the preset target ramp, and the upstream boundary is the upstream ramp of the preset target ramp in the corresponding area of ​​the preset target section or the boundary of the preset target section closest to the preset target ramp.

[0047] The boundary position information of the upstream section includes the regional position information of the preset target ramp in the corresponding area of ​​the preset target section and the boundary information of the upstream boundary. The boundary information of the upstream boundary can be the regional position information of the upstream ramp of the preset target ramp in the corresponding area of ​​the preset target section or the boundary information of the boundary of the preset target section closest to the preset target ramp. The position information of the floating vehicle is compared with the boundary position information of the upstream section to determine whether the floating vehicle is located in the upstream section, thereby filtering out the floating vehicles located in the upstream section to determine the first set.

[0048] The boundary position information of the downstream section includes the regional position information of the preset target ramp in the corresponding area of ​​the preset target section and the boundary information of the downstream boundary. The boundary information of the downstream boundary can be the regional position information of the downstream ramp of the preset target ramp in the corresponding area of ​​the preset target section or the boundary information of the boundary of the preset target section closest to the preset target ramp. The position information of the floating vehicle is compared with the boundary position information of the downstream section to determine whether the floating vehicle is located in the downstream section, thereby filtering out the floating vehicles located in the downstream section to determine the second set.

[0049] Optionally, in an embodiment of the present application, based on the position information, determining the first set and the second set may include the following contents. Using ArcGIS software, the position information of the preset target section and the floating car is matched, and the matching result is displayed. For any preset target ramp, the user can obtain the floating car in the upstream section and the floating car in the downstream section, in other words, the first set and the second set can be obtained. The user inputs the first set and the second set, receives the first set and the second set, and thus the first set and the second set can be determined. Alternatively, the spatial selection tool of ArcGIS software can be used to determine the floating car in the upstream section and the floating car in the downstream section to determine the first set and the second set. Specifically, the following contents can be referred to.

[0050] Based on ArcGIS software, the overall information of the preset target road section and the overall information of at least one preset target ramp, a layer of the preset target road section and at least one preset target ramp is constructed to display the preset target road section and at least one preset target ramp. A rectangular frame is constructed with the corresponding area of ​​each preset target ramp in the preset target road section as the boundary, and the boundary of the preset target road section is combined to split the preset target road section, such as Figure 2 As shown, the rectangular box corresponding to the first section, the rectangular box corresponding to the second section, the rectangular box corresponding to the third section, the rectangular box corresponding to the fourth section, and the rectangular box corresponding to the fifth section are split. It should be noted that Figure 2Only the situation of some sections of the preset target section is shown. In addition, the rectangular boxes can also be numbered according to the direction of traffic flow for easy marking. The corresponding floating vehicle trajectory data within the preset target section is extracted from the database, and the floating vehicle trajectory data is matched to the preset target section using ArcGIS software. The matching results are displayed. Based on the matching results, the user can obtain the floating vehicles in each rectangular box, thereby obtaining the first set and the second set, and the user can input the obtained first set and the second set. It should be noted that the set of GPS points of the floating vehicles displayed in the matching results does not represent the set of floating vehicles, because there may be multiple GPS points of the same floating vehicle, and deduplication processing is required to obtain the set of floating vehicles. For example, deduplication processing is performed according to an identification attribute of the floating vehicle (such as a license plate number, etc.).

[0051] Alternatively, after the floating vehicle trajectory data is successfully matched, the floating vehicle GPS points falling in each rectangular frame can be obtained separately using the spatial selection tool. Since multiple trajectory points of a vehicle may be stored in the same rectangular frame, and what is desired to be obtained is a collection of floating vehicles, the unique identification attribute of the floating vehicle GPS point (such as the license plate number, etc.) is used for deduplication processing, and the unique floating vehicle GPS point with the same identification is retained. Thus, a first set and a second set are obtained for each preset target ramp. Optionally, in an embodiment of the present application, a statistical period for the collection of floating vehicles may be set, specifically, it may be determined according to the specific circumstances. For example, 5 minutes is taken as a data period, and statistics of floating vehicles are performed every 5 minutes.

[0052] Optionally, in the embodiment of the present application, when the preset target road section includes an upward main road and a downward main road, the acquired first vehicle information needs to be differentiated, and the first floating vehicle quantity is determined according to the differentiated result.

[0053] The preset target road section includes an upward main road and a downward main road, and the first vehicle information also includes an azimuth. Before determining the first floating vehicle quantity based on the position information for any preset target ramp, the method further includes the following contents.

[0054] Based on the azimuth, determine the first vehicle information belonging to the ascending main road and the first vehicle information belonging to the descending main road. Specifically, determine the first vehicle information belonging to the ascending main road and the first vehicle information belonging to the descending main road according to the following content. When the azimuth is within the range of [0,90°]∪[270°,360°], the first vehicle information belongs to the ascending main road; when the azimuth is within the range of [90°,270°], the first vehicle information belongs to the descending main road. In addition, a driving direction field can be added to the first vehicle information. After distinguishing based on the azimuth, for any preset target ramp, determining the first floating vehicle number based on the position information includes determining the first floating vehicle number based on the position information in the first vehicle information belonging to the main road connected to the preset target ramp. Figure 2 As shown, a first floating vehicle number is determined for the second entrance ramp, and the first floating vehicle number is determined based on position information in first vehicle information belonging to a main road connected to the second entrance ramp.

[0055] Optionally, in the embodiment of the present application, after obtaining the first vehicle information of the floating vehicle in the preset target section, the obtained first vehicle information may be preprocessed, and then the ramp flow rate is determined for any preset target ramp based on the preprocessed first vehicle information. Specifically, the preprocessing may include at least one of the following: deleting speed error data, repairing drift data, and deleting speed abnormal data.

[0056] Deleting speed error data may include the following. The first vehicle information also includes the speed of the floating vehicle. Data in the first vehicle information whose speed does not meet the preset speed condition is error data and needs to be deleted. Specifically, the speed in the first vehicle information is compared with the preset speed condition. If the preset speed condition is not met, it is deleted. The preset speed condition may be determined according to specific circumstances. For example, the preset speed condition may be that the speed does not exceed 120% of the maximum speed limit. The first vehicle information in which the speed exceeds 120% of the maximum speed limit is deleted. The maximum speed limit is the maximum speed limit of the main road.

[0057] Repairing drift data may include the following contents. Drift data is data whose position information in the first vehicle information is not within the preset target road section range, and these data need to be repaired so that these data can be within the preset target road section range. Specifically, the following contents can be referred to for processing. Since the floating vehicle trajectory data may have position deviation due to the problem of GPS accuracy, some vehicles cannot be accurately located on the road most of the time, and in order to accurately obtain the number of floating vehicles on the main road, these drifting positioning points must be "pulled" to the main road. In most cases, when the floating vehicle data is matched to the road network map, an overall offset will occur. At this time, the offset data can be translated to the correct position using ArcGIS software, that is, "pulled" over; for some drifting data points, the road buffer can be appropriately widened by increasing the buffer range, and the floating vehicle GPS points near the road are included in the road network. In addition, the road range can be appropriately expanded when extracting data. For example, a 50-meter wide buffer is generated on both sides of the road line, and all drift points in the buffer are included in the preset target road section range.

[0058] Deleting abnormal speed data may include the following. Vehicle position overlap refers to the phenomenon that vehicle trajectory points appear superimposed and clustered. In the technical solution of the present application, the ultimate goal is to obtain the number of vehicles. Multiple trajectory points of the same vehicle are of little significance to the present application, because one trajectory point in the same area is sufficient to represent a vehicle, and the remaining redundant data increases the amount of calculation. Therefore, it is necessary to pre-process the data and remove redundant data. Specifically, the removal of redundant data can be performed according to the unique identification attribute of the floating vehicle (such as the license plate number) as described in the above content. For a trajectory data group of a certain vehicle, when the speed has been at a low value and the position information change is basically zero, this group of trajectory data groups belongs to speed abnormal data, then the first vehicle information corresponding to a single GPS point data in the trajectory data group is retained, and the rest is deleted.

[0059] Optionally, in the embodiment of the present application, before determining the floating vehicle penetration rate based on the main road flow and the second floating vehicle number for any preset target ramp and any detection position, the method further includes the following: preprocessing the acquired second vehicle information, wherein the preprocessing includes at least one of the following: repairing missing data, deleting erroneous data, and deleting abnormal combination data.

[0060] In the embodiment of the present application, the second vehicle information may include data collection time, speed and time occupancy rate in addition to the main road traffic. Due to the influence of problems such as failure of certain detection equipment on the road, extreme weather, abnormal data transmission, etc., the second vehicle information detected by the fixed detector will have abnormal data, and the abnormal data mainly includes missing data, erroneous data and abnormal combination data.

[0061] Missing data refers to data in which a certain parameter or several parameters in the second vehicle information do not have specific values. Missing data mainly manifests itself in two forms. The first form is that the specific values ​​of one or several parameters in the second vehicle information corresponding to only a few data collection times are missing. The second form is that data is missing in the second vehicle information corresponding to continuous time. For missing data, it is generally possible to use the upstream and downstream of the missing data in time and space and the historical data of the same period to infer and repair it under certain reliable conditions. For the first form, a simple interpolation method can be used for repair processing. For the second, the moving average method is used for repair.

[0062] In the technical solution provided in the embodiment of the present application, for a certain set of second vehicle information data sets, when a certain parameter does not obtain a value, it can be replaced by "-1". For the first form, a simple interpolation method can be used for repair processing. The principle of the simple interpolation method is as follows: In the formula, t is the time point of missing data, y t is the value of parameter y after patching at time t; y t-1 is the parameter y detection data at time t-1; t+1 is the detection data of parameter y at time t+1. Parameter y can be the main road flow, speed or time occupancy.

[0063] For the second form, the moving average method is used for repair. The principle of the moving average method is as follows: Where t is the time point of missing data; m t is the value of parameter m after patching at time t; n is the scale of data moving forward; m t-1 is the detection value of parameter m at time t-1, and so on, m t-n is the detected value of parameter m at time tn.

[0064] The erroneous data is the second vehicle information that does not meet the preset threshold conditions. In the embodiment of the present application, the erroneous data is mainly processed by using the preset threshold conditions. Specifically, in the embodiment of the present application, threshold conditions are set for the main road flow, speed and time occupancy, and the data that does not meet the threshold conditions are deleted.

[0065] The threshold condition of the main road flow Q is to satisfy the first formula, where the first formula is: 0≤Q≤f c ×C×T×n. In the formula, C is the road capacity (veh / h), and the single lane of the expressway is generally set to 2100veh / h; T is the sampling time interval of the second vehicle information (min). In the embodiment of the present application, the sampling time interval can be set to 2min; f cis the first correction coefficient, usually ranging from 1.3 to 1.5; n is the number of lanes in the section.

[0066] The threshold condition of speed V is to satisfy the second formula, where the second formula is: 0≤V≤f v ×v p In the formula, v p is the road design speed, generally 80km / h; f v is the second correction coefficient, which is usually in the range of 1.2.

[0067] The threshold condition of the time occupancy rate O is to satisfy the third formula, wherein the third formula is 0≤O≤100%. In the formula, O is the time occupancy rate.

[0068] Abnormal combination data is the second vehicle information that does not meet the preset combination conditions. The preset combination conditions are Q = K × V. In the formula, Q is the main road traffic microwave; K is the road density, where there is a conversion relationship between road density and time occupancy; V is the speed. Using the preset combination conditions and traffic flow theory, abnormal combination data can be identified and deleted. For example, as shown in Table 1.

[0069] Table 1 Abnormal combination data

[0070]

[0071] In summary, the technical solution provided by the embodiment of the present application has the following advantages:

[0072] 1) Estimate the ramp flow based on the data of the floating vehicle and the data obtained by the fixed detector. The acquisition of the data of the floating vehicle and the fixed detector is relatively convenient and inexpensive. The ramp flow can be obtained at a relatively low cost, and the application can be applied to the situation of multiple entry and exit ramps;

[0073] 2) This application takes into account the impact of floating vehicle penetration rate on flow estimation, selects multiple detectors on the same road section to study the floating vehicle penetration rate, and fully considers the differences in vehicle distribution on different road sections, so that the calculated penetration rate can best represent the floating vehicle penetration rate of each entrance and exit ramp on the study section, thereby improving the accuracy of flow estimation;

[0074] 3) Since the data from floating vehicles and fixed detectors are real-time, with the help of certain programming methods, this application can achieve real-time estimation and monitoring of ramp flow, thereby providing data support for road congestion relief.

[0075] In a second aspect, an embodiment of the present application also provides a device for determining the ramp flow of a ramp.

[0076] Figure 3 is a structural block diagram of an apparatus for determining ramp flow of a ramp provided by another embodiment of the present application. Figure 3 As shown, the device includes a first vehicle information acquisition module 1 and a ramp flow determination module 2. The first vehicle information acquisition module 1 is used to acquire the first vehicle information of a floating vehicle in a preset target section, wherein the preset target section at least includes an upstream section and a downstream section of at least one preset target ramp, and the first vehicle information at least includes position information; for a preset target ramp, the upstream section is a section between the preset target ramp in a corresponding area of ​​the preset target section and an upstream boundary of the preset target ramp, the downstream section is a section between the preset target ramp in a corresponding area of ​​the preset target section and a downstream boundary of the preset target ramp, the upstream boundary is a boundary of the upstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or a preset target section that is closest to the preset target ramp, and the downstream boundary is a boundary of the downstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or a preset target section that is closest to the preset target ramp. The nearest boundary to the preset target ramp; a ramp flow determination module, used to perform the following contents for any preset target ramp: determine a first floating vehicle number based on the position information, wherein the first floating vehicle number is the number of floating vehicles at the preset target ramp; obtain second vehicle information and a second floating vehicle number of vehicles at at least one detection position, wherein the second vehicle information at least includes the main road flow, the second floating vehicle number at any detection position is the number of floating vehicles at the detection position, and at least one detection position is located between the upstream boundary and the downstream boundary; for any detection position, determine the permeability of floating vehicles based on the main road flow and the second floating vehicle number; and determine the ramp flow of the preset target ramp based on the first floating vehicle number and the permeability corresponding to at least one of the at least one detection position.

[0077] Optionally, in an embodiment of the present application, for any preset target ramp, based on the location information, determining the first number of floating vehicles includes: determining a first set and a second set based on the location information, wherein the first set is a set of floating vehicles included in the upstream section, and the second set is a set of floating vehicles included in the downstream section; and determining the first number of floating vehicles based on the first set and the second set.

[0078] Optionally, in an embodiment of the present application, based on the position information, the first set and the second set are determined, including: comparing the position information with the boundary position information of the upstream section to determine the floating vehicles in the upstream section to determine the first set; and comparing the position information with the boundary position information of the downstream section to determine the floating vehicles in the downstream section to determine the second set.

[0079] Optionally, in an embodiment of the present application, the preset target road section includes an ascending main road and a descending main road, the first vehicle information also includes an azimuth, and before determining the first number of floating vehicles based on the position information for any preset target ramp, the method also includes: determining the first vehicle information belonging to the ascending main road and the first vehicle information belonging to the descending main road based on the azimuth; wherein, for any preset target ramp, determining the first number of floating vehicles based on the position information includes determining the first number of floating vehicles based on the position information in the first vehicle information belonging to the main road connected to the preset target ramp.

[0080] Optionally, in an embodiment of the present application, before determining the penetration rate of floating vehicles based on the main road flow and the number of second floating vehicles for any preset target ramp and for any detection location, the method also includes: preprocessing the acquired second vehicle information, wherein the preprocessing includes at least one of the following: repairing missing data, deleting erroneous data, and deleting abnormal combination data.

[0081] The specific working principle and benefits of the device for determining the ramp flow of a ramp provided in an embodiment of the present application are similar to the specific working principle and benefits of the method for determining the ramp flow of a ramp provided in an embodiment of the present application, and will not be repeated here.

[0082] In a third aspect, an embodiment of the present application further provides a machine-readable storage medium, on which instructions are stored, and when the instructions are executed by a processor, the processor is configured to execute the steps of the method described in the above embodiment.

[0083] The preferred embodiments of the present application are described in detail above; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

[0084] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

[0085] In addition, the various implementation modes of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

Claims

1. A method for determining a ramp flow rate of a ramp, characterized in that: The method includes: Acquire first vehicle information of a floating vehicle in a preset target section, wherein the preset target section at least includes an upstream section and a downstream section of at least one preset target ramp, and the first vehicle information at least includes position information; for a preset target ramp, the upstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and an upstream boundary of the preset target ramp, the downstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and a downstream boundary of the preset target ramp, the upstream boundary is a boundary of the upstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or the preset target section that is closest to the preset target ramp, and the downstream boundary is a boundary of the downstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or the preset target section that is closest to the preset target ramp; For any of the preset target ramps, perform the following: Based on the position information, determining a first number of floating vehicles, wherein the first number of floating vehicles is the number of floating vehicles at the preset target ramp; Acquire second vehicle information and a second floating vehicle quantity of vehicles at at least one detection position, wherein the second vehicle information at least includes the main road flow, the second floating vehicle quantity at any of the detection positions is the quantity of the floating vehicles at the detection position, and the at least one detection position is located between the upstream boundary and the downstream boundary; For any of the detection positions, based on the main road flow and the second number of floating vehicles, determining the floating vehicle penetration rate, wherein the floating vehicle penetration rate is obtained by dividing the second number of floating vehicles by the main road flow; and determining the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position; Wherein, determining the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position includes: In a case where the at least one detection position includes only one detection position, dividing the first number of floating vehicles by the permeability corresponding to the detection position to obtain the ramp flow of the preset target ramp; In the case where the at least one detection position includes a plurality of detection positions, the ramp flow of the preset target ramp is obtained by dividing the first number of floating vehicles by any one of the following: The permeability corresponding to the detection position closest to the preset target ramp among the at least one detection position, the average value of the permeability corresponding to a preset value of detection positions close to the preset target ramp among the at least one detection position, and the average value of the permeability corresponding to the multiple detection positions.

2. The method according to claim 1, characterized in that For any of the preset target ramps, determining a first number of floating vehicles based on the position information includes: Based on the position information, determining a first set and a second set, wherein the first set is a set of the floating vehicles included in the upstream section, and the second set is a set of the floating vehicles included in the downstream section; and The first number of floating vehicles is determined based on the first set and the second set.

3. The method according to claim 2, characterized in that Based on the location information, determining a first set and a second set includes: Comparing the position information with the boundary position information of the upstream section to determine the floating vehicle in the upstream section, so as to determine the first set; and The position information is compared with the boundary position information of the downstream section to determine the floating vehicle in the downstream section, so as to determine the second set.

4. The method according to claim 1, characterized in that: The preset target road section includes an upward main road and a downward main road, the first vehicle information also includes an azimuth, and before determining the first floating vehicle quantity based on the position information for any of the preset target ramps, the method further includes: Based on the azimuth, determining the first vehicle information belonging to the upgoing main road and the first vehicle information belonging to the downgoing main road; Wherein, for any of the preset target ramps, determining the first number of floating vehicles based on the position information includes determining the first number of floating vehicles based on the position information in the first vehicle information belonging to a main road connected to the preset target ramp.

5. The method according to claim 1, characterized in that Before determining the floating vehicle penetration rate for any of the preset target ramps and any of the detection positions based on the main road flow and the second floating vehicle number, the method further includes: The acquired second vehicle information is preprocessed, wherein the preprocessing includes at least one of the following: repairing missing data, deleting erroneous data, and deleting abnormal combination data.

6. A device for determining the ramp flow of a ramp, characterized in that: The device includes: A first vehicle information acquisition module is used to acquire first vehicle information of a floating vehicle in a preset target section, wherein the preset target section at least includes an upstream section and a downstream section of at least one preset target ramp, and the first vehicle information at least includes position information; for a preset target ramp, the upstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and an upstream boundary of the preset target ramp, and the downstream section is a section of the preset target ramp between a corresponding area of ​​the preset target section and a downstream boundary of the preset target ramp, the upstream boundary is a boundary of the upstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or the preset target section that is closest to the preset target ramp, and the downstream boundary is a boundary of the downstream ramp of the preset target ramp in a corresponding area of ​​the preset target section or the preset target section that is closest to the preset target ramp; The ramp flow determination module is used to execute the following contents for any preset target ramp: Based on the position information, determining a first number of floating vehicles, wherein the first number of floating vehicles is the number of floating vehicles at the preset target ramp; Acquire second vehicle information and a second floating vehicle quantity of vehicles at at least one detection position, wherein the second vehicle information at least includes the main road flow, the second floating vehicle quantity at any of the detection positions is the quantity of the floating vehicles at the detection position, and the at least one detection position is located between the upstream boundary and the downstream boundary; For any of the detection positions, based on the main road flow and the second number of floating vehicles, determining the floating vehicle penetration rate, wherein the floating vehicle penetration rate is obtained by dividing the second number of floating vehicles by the main road flow; and determining the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position; Wherein, determining the ramp flow of the preset target ramp based on the first number of floating vehicles and the permeability corresponding to at least one of the at least one detection position includes: In a case where the at least one detection position includes only one detection position, dividing the first number of floating vehicles by the permeability corresponding to the detection position to obtain the ramp flow of the preset target ramp; In the case where the at least one detection position includes a plurality of detection positions, the ramp flow of the preset target ramp is obtained by dividing the first number of floating vehicles by any one of the following: The permeability corresponding to the detection position closest to the preset target ramp among the at least one detection position, the average value of the permeability corresponding to a preset value of detection positions close to the preset target ramp among the at least one detection position, and the average value of the permeability corresponding to the multiple detection positions.

7. The device according to claim 6, characterized in that For any of the preset target ramps, determining a first number of floating vehicles based on the position information includes: Based on the position information, determining a first set and a second set, wherein the first set is a set of the floating vehicles included in the upstream section, and the second set is a set of the floating vehicles included in the downstream section; and The first number of floating vehicles is determined based on the first set and the second set.

8. The device according to claim 7, characterized in that Based on the location information, determining a first set and a second set includes: Comparing the position information with the boundary position information of the upstream section to determine the floating vehicle in the upstream section, so as to determine the first set; and The position information is compared with the boundary position information of the downstream section to determine the floating vehicle in the downstream section, so as to determine the second set.

9. The device according to claim 6, characterized in that The preset target road section includes an upward main road and a downward main road, and the first vehicle information also includes an azimuth. Before determining the first floating vehicle quantity based on the position information for any of the preset target ramps, the device may further perform the following method: Based on the azimuth, determining the first vehicle information belonging to the upgoing main road and the first vehicle information belonging to the downgoing main road; Wherein, for any of the preset target ramps, determining the first number of floating vehicles based on the position information includes determining the first number of floating vehicles based on the position information in the first vehicle information belonging to a main road connected to the preset target ramp.

10. A machine-readable storage medium, characterized in that: The machine-readable storage medium stores instructions, which, when executed by a processor, cause the processor to be configured to perform the steps of the method according to any one of claims 1 to 5.

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