Vehicle detection device, vehicle detection method, and vehicle detection program

Abstract

To detect vehicles by reliably discriminating a large-sized vehicle traveling alone from a plurality of small-sized vehicles traveling in parallel.SOLUTION: A vehicle detection device 10 includes a detection point extraction section 31, a clustering processing section 32, a dispersion information calculation section 33, and a vehicle type determination section 34. The detection point extraction section 31 extracts a plurality of detection points from a reception signal obtained by reflection against a vehicle traveling on a road. The clustering processing section 32 groups the plurality of detection points in response to features of the detection points. The dispersion information calculation section 33 calculates dispersion information of positions of the plurality of detection points grouped into one group. The vehicle type determination section 34 determines whether there is a large-sized vehicle traveling alone or there are a plurality of small-sized vehicles traveling in parallel, based on the dispersion information.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a technique for detecting the type of vehicle traveling on a road. [Background technology]

[0002] Conventionally, various techniques have been devised for identifying the type of vehicle traveling on a road. For example, a traffic volume survey device disclosed in Patent Document 1 calculates the duration of a reflected wave obtained from a vehicle traveling on a road.

[0003] The traffic volume survey device of Patent Document 1 uses this duration to identify the type of vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-272988 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional vehicle identification technology, it is difficult to distinguish between a large vehicle traveling alone and multiple small vehicles (passenger cars, etc.) traveling side by side.

[0006] An object of the present invention is to more reliably distinguish and detect a large vehicle traveling alone from a plurality of small vehicles (passenger cars, etc.) traveling side by side. [Means for solving the problem]

[0007] In order to achieve the above object, the vehicle detection device of the present invention is configured as follows.

[0008] This vehicle detection device detects the type of vehicle traveling on a road. The vehicle detection device includes a detection point extraction unit, a clustering processing unit, a variation information calculation unit, and a vehicle type determination unit. The detection point extraction unit extracts multiple detection points from a received signal obtained by reflection from a vehicle traveling on the road. The clustering unit groups the multiple detection points according to their characteristics. The variation information calculation unit calculates variation information of the positions of the multiple detection points grouped into one group. The vehicle type determination unit determines whether the detection point is a large vehicle traveling alone or multiple small vehicles traveling side by side from the variation information.

[0009] In this configuration, the variation of the multiple detection points obtained for each group of a large vehicle traveling alone (first group of detection points) and multiple small vehicles traveling side by side (second group of detection points) is different, so by using this variation, it is possible to determine whether the vehicle is a large vehicle traveling alone or multiple small vehicles traveling side by side.

[0010] The vehicle type determination unit may determine whether the vehicle is a single large vehicle or multiple small vehicles traveling side by side, based on information about variations in the traveling direction of the vehicles on the road.

[0011] The vehicle type determination unit may determine that the vehicle is a large vehicle traveling alone if the variation information of the vehicle's traveling direction is equal to or greater than a threshold for determining whether the vehicle is a large vehicle, and may determine that the vehicle is a multiple small vehicle traveling side by side if the variation information of the vehicle's traveling direction is less than the threshold for determining whether the vehicle is a large vehicle.

[0012] The vehicle type determination unit may determine whether the vehicle is a large vehicle traveling alone or a small vehicle traveling alone based on information about the variation in the width direction on the road.

[0013] The vehicle type determination unit may determine that the vehicle is a small vehicle traveling alone if the width direction variation information is less than a threshold value for determining that the vehicle is a small vehicle.

[0014] The vehicle may include a detection unit that emits detection waves onto the road and outputs the received signals. Effect of the Invention

[0015] According to the present invention, it is possible to more reliably detect and distinguish between a large vehicle traveling alone and a plurality of small vehicles (passenger cars, etc.) traveling side by side. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a diagram illustrating the concept of a vehicle detection technique according to this example. [Diagram 2] 2 is a block diagram showing a configuration example of a vehicle detection device according to this embodiment. FIG. [Diagram 3] FIG. 2 is a diagram showing an example of installation of a radar 20. [Figure 4] 2 is a block diagram showing an example of the configuration of a signal processing unit 30. FIG. [Diagram 5] 4 is a flowchart showing an operation of the vehicle detection device. [Figure 6] 10 is a flowchart showing the operation of the vehicle detection device of the first modified example. [Figure 7] 10 is a flowchart showing the operation of a vehicle detection device according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described.

[0018] <1. Application Examples> FIG. 1(A), FIG. 1(B), and FIG. 1(C) are diagrams illustrating the concept of the vehicle detection technology according to this example.

[0019] The radar 20 transmits detection waves so as to be included in the detection range of the road 80. The radar 20 receives reflected waves from vehicles traveling on the road 80 and outputs a received signal. The vehicle detection device 10 extracts a plurality of detection points from the received signal output from the radar 20.

[0020] The vehicle detection device 10 performs clustering processing on the multiple detection points, and groups each group of multiple detection points that are thought to be vehicles, as shown in Figures 1(A), 1(B), and 1(C). The vehicle detection device 10 detects variation information of the position coordinates of the multiple detection points in each group.

[0021] The vehicle detection device 10 judges from the variation information whether each group is a small vehicle traveling alone, a large vehicle traveling alone, or small vehicles traveling side by side.

[0022] 1(A) and 1(C), the variation length Lt of the multiple detection points for the large vehicle 90t is greater than the variation length Lc of the multiple detection points for the small vehicles 90c1 and 90c2 running parallel to it. The vehicle detection device 10 can distinguish between the large vehicle 90t running alone and the small vehicles 90c1 and 90c2 running parallel to it by using the difference between the variation length Lt of the large vehicle 90t and the variation length Lc of the small vehicles 90c1 and 90c2 running parallel to it.

[0023] 1(A) and 1(B), the variation width Wt of the multiple detection points for the large vehicle 90t is larger than the variation width Wc of the multiple detection points for the small vehicle 90c. The vehicle detection device 10 can distinguish between the large vehicle 90t traveling alone and the small vehicle 90c traveling alone by using the difference between the variation width Wt of the large vehicle 90t and the variation width Wc of the small vehicle 90c.

[0024] <2. Configuration example> Fig. 2 is a block diagram showing a configuration example of a vehicle detection device according to this embodiment. As shown in Fig. 2, the vehicle detection device 10 includes a radar 20, a signal processing unit 30, and a communication unit 40. The radar 20 and the communication unit 40 may be located outside the vehicle detection device 10.

[0025] 3(A) and 3(B) are diagrams showing an example of installation of the radar 20. As shown in FIG. 3(A) and FIG. 3(B), the radar 20 is installed on a road 80 on which vehicle detection is performed. More specifically, for example, the radar 20 is installed at approximately the center of the width direction of the road 80 (x-axis direction in FIG. 3(A) and FIG. 3(B)). Furthermore, the radar 20 is installed at a position at a predetermined height (z-axis direction in FIG. 3(A) and FIG. 3(B)) from the road surface of the road 80. In this case, the radar 20 is installed on the road surface of the road 80 so as to be able to detect within a predetermined range in the direction in which the road 80 extends (vehicle travel direction: y-axis direction in FIG. 3(A) and FIG. 3(B)) and the width direction (x-axis direction in FIG. 3(A) and FIG. 3(B)).

[0026] The radar 20 irradiates detection waves (e.g., millimeter waves) within a predetermined range on the road 80, receives reflected waves from vehicles and the like on the road 80, and generates a received signal. The radar 20 irradiates the detection waves and generates the associated received signal at predetermined time intervals. The radar 20 outputs the received signal to the signal processing unit 30.

[0027] The radar 20 is, for example, a millimeter wave radar, but may be another type of radar as long as it can irradiate detection waves onto the road 80 and obtain the received signal. However, by using a millimeter wave radar, it is possible to accurately detect vehicles located relatively far from the radar 20. Also, the radar is not limited to a radar, and a device that can irradiate detection waves onto the road 80 and obtain the received signal can also be used.

[0028] Fig. 4 is a block diagram showing an example of the configuration of the signal processing unit 30. As shown in Fig. 4, the signal processing unit 30 includes a detection point extraction unit 31, a clustering processing unit 32, a variation information calculation unit 33, and a vehicle type determination unit .

[0029] The detection point extraction unit 31 extracts detection points from the received signal output from the radar 20. For example, the detection point extraction unit 31 stores a target detection threshold, and extracts points in the received signal that exceed the target detection threshold as detection points. At this time, the detection point extraction unit 31 detects the position coordinates of the detection points, and outputs the detection points together with the position coordinates to the clustering processing unit 32.

[0030] The clustering processing unit 32 extracts a plurality of detection points estimated to be vehicles based on the position coordinates, speed, and signal level of the plurality of detection points. The clustering processing unit 32 groups the plurality of detection points estimated to be vehicles into groups each estimated to be one vehicle based on the position coordinates of the plurality of detection points. The clustering processing unit 32 outputs the grouped plurality of detection points to the variation information calculation unit 33.

[0031] The variation information calculation unit 33 calculates variation information of the multiple detection points that make up the group. More specifically, the variation information calculation unit 33 calculates a variation width W and a variation length L for the position coordinates of the multiple detection points that make up the group.

[0032] The variation width W is a difference value between the position coordinates of both ends in the width direction of the road 80 in the position coordinates of the multiple detection points that make up the group. The variation length L is a difference value between the position coordinates of both ends in the direction in which the road 80 extends (the vehicle travel direction) in the position coordinates of the multiple detection points that make up the group.

[0033] The variation information calculation unit 33 associates the variation length L with the variation width W for each group, and outputs the result to the vehicle type determination unit .

[0034] The vehicle type determination unit 34 determines the vehicle type for each group of multiple detection points from the variation length L and the variation width W. More specifically, the vehicle type determination unit 34 distinguishes between a large vehicle traveling alone, multiple small vehicles traveling in parallel, and a small vehicle traveling alone, by the following method.

[0035] As described above with reference to Figures 1(A), 1(B), and 1(C), the variation length Lt of the multiple detection points for the large vehicle 90t is greater than the variation length Lcp of the multiple detection points for the small vehicles 90c1 and 90c2 running parallel to each other. Also, the variation width Wt of the multiple detection points for the large vehicle 90t is greater than the variation width Wc of the multiple detection points for the small vehicle 90c.

[0036] The vehicle type determination unit 34 uses the difference between the variation length L and the variation width W to determine the vehicle type.

[0037] The vehicle type determination unit 34 sets a threshold value for determining whether the vehicle is a small vehicle with respect to the variation width W. The threshold value for determining whether the vehicle is a small vehicle is set, for example, by detecting a representative value of the variation width Wt of large vehicles and a representative value of the variation width Wc of small vehicles through past demonstration experiments or the like, and setting the threshold value for determining whether the vehicle is a small vehicle, for example, by the intermediate value of these representative values.

[0038] If the variation width of the group is less than the threshold value for determining a small vehicle (in the case of the variation width Wc in FIG. 1(B)), the vehicle type determination unit 34 determines that the vehicle is a small vehicle 90c traveling alone.

[0039] The vehicle type determination unit 34 sets a threshold value for determining whether the vehicle is a large vehicle with respect to the variation length L. The threshold value for determining whether the vehicle is a large vehicle is set, for example, by detecting a representative value of the variation length Lt of large vehicles and a representative value of the variation length Lc of small vehicles through past demonstration experiments or the like, and setting the threshold value for determining whether the vehicle is a large vehicle, for example, by the median value of these representative values.

[0040] If the variation length of the group is equal to or greater than the threshold for determining a large vehicle (variation length Lt in FIG. 1A), the vehicle type determination unit 34 determines that the vehicle is a large vehicle 90t traveling alone. If the variation length of the group is less than the threshold for determining a large vehicle (variation length Lc in FIG. 1C), the vehicle type determination unit 34 determines that the vehicle is a group of small vehicles 90c1, 90c2 traveling side by side.

[0041] By performing such processing, the vehicle type determination unit 34 can more reliably distinguish between the large vehicle 90t traveling alone and the multiple small vehicles 90c1, 90c2 traveling side by side. Furthermore, the vehicle type determination unit 34 can more reliably distinguish between the large vehicle 90t traveling alone and the small vehicle 90c traveling alone. Furthermore, by using these results, the vehicle type determination unit 34 can more reliably distinguish between the multiple small vehicles 90c1, 90c2 traveling side by side and the small vehicle 90c traveling alone.

[0042] The vehicle type determination unit 34 outputs the determination result to the communication unit 40. The communication unit 40 transmits the determination result to, for example, a higher-level system connected via a network.

[0043] The vehicle type determination unit 34 can calculate the vehicle speed for each group using the position coordinates of the detection points at multiple times included in the group, etc. In this case, the vehicle type determination unit 34 can output the vehicle speed together with the vehicle type as the determination result, and transmit it to, for example, a higher-level network through the communication unit 40.

[0044] <3. Example of operation> The operation of the vehicle detection device 10 of this embodiment will be described below. Fig. 5 is a flowchart showing the operation of the vehicle detection device.

[0045] The radar 20 emits a sensing wave and generates a reception signal from the wave reflected by this sensing wave (S11).

[0046] The detection point extraction unit 31 extracts a plurality of detection points from the received signal (S12). The clustering processing unit 32 performs clustering processing on the plurality of detection points to group them (S13).

[0047] The variation information calculation unit 33 calculates variation information for each group (S13). The variation information includes a variation width W in the width direction of the road 80 and a variation length L in the extension direction of the road 80, which are calculated from the position coordinates of the multiple detection points that make up the group.

[0048] If the variation width W is less than the threshold value (threshold value for determining small vehicles), in other words, if the variation width W is not greater than or equal to the threshold value (threshold value for determining small vehicles) (S14: NO), the vehicle type determination unit 34 determines that the vehicle is a small vehicle (a small vehicle traveling alone) (S15).

[0049] If the variation width W is equal to or greater than the threshold value (threshold value for determining a small vehicle) (S14: YES), the vehicle type determination unit 34 proceeds to a determination using the variation length L.

[0050] If the variation length L is equal to or greater than the threshold (threshold for determining large vehicles) (S16: YES), the vehicle type determination unit 34 determines that the vehicle is a large vehicle (a large vehicle traveling alone) (S17). If the variation length L is not equal to or greater than the threshold (threshold for determining large vehicles) (S16: NO), the vehicle type determination unit 34 determines that the vehicle is a plurality of small vehicles traveling side by side (S18).

[0051] In this way, the vehicle detection device 10 of this example can more reliably distinguish between the large vehicle 90t traveling alone and the multiple small vehicles 90c1, 90c2 traveling side by side. Furthermore, the vehicle detection device 10 can more reliably distinguish between the large vehicle 90t traveling alone and the small vehicle 90c traveling alone. Furthermore, the vehicle detection device 10 can more reliably distinguish between the multiple small vehicles 90c1, 90c2 traveling side by side and the small vehicle 90c traveling alone.

[0052] In the above-described vehicle detection device 10, the variation width and the variation length are used as the variation state of the multiple detection points. However, the variation state of the multiple detection points is not limited to this, and for example, it is also possible to use a statistical value representing the variation such as the variance or standard deviation of the position coordinates of the multiple detection points constituting a group.

[0053] <4. Modifications> Next, a modified example of the vehicle detection device will be described.

[0054] Variation 1 Fig. 6 is a flowchart showing the operation of the vehicle detection device of Modification 1. As shown in Fig. 6, the vehicle detection device of Modification 1 is different in that it judges a small vehicle traveling alone without using the variation width.

[0055] After the clustering process (S13), the vehicle detection device of the first modification judges whether the vehicle is a small vehicle traveling alone (S20). of The determination is realized, for example, based on an area occupied by a plurality of grouped detection points, etc. Note that other methods may be used to determine whether a small vehicle is traveling alone.

[0056] When the vehicle detection device of the first modified example determines that the vehicle is not a small vehicle traveling alone (S20: NO), it calculates variation information for each group (S13) and determines whether the vehicle is a large vehicle traveling alone or a number of small vehicles traveling side by side.

[0057] Variation 2 Fig. 7 is a flowchart showing the operation of the vehicle detection device of Modification 2. As shown in Fig. 7, the vehicle detection device of Modification 2 differs in that it uses the amount of change in dispersion to distinguish between a large vehicle traveling alone and multiple small vehicles traveling side by side.

[0058] After identifying a small vehicle traveling alone, the vehicle detection device of the second modification calculates the amount of change in the variation (amount of change over time) of the position coordinates of the grouped detection points. If the amount of change in the variation is equal to or less than a threshold (S30: YES), the vehicle detection device of the second modification determines that the vehicle is a large vehicle (S17). If the amount of change in the variation is greater than the threshold (S30: NO), the vehicle detection device of the second modification determines that the vehicle is a plurality of small vehicles traveling side by side (S18).

[0059] This is because, for example, it is considered that the positional relationship of the multiple detection points constituting a group is more likely to change over time for multiple small vehicles traveling side by side than for a large vehicle traveling alone. Therefore, by using the amount of change in the dispersion, it is possible to distinguish and detect a large vehicle traveling alone from multiple small vehicles traveling side by side.

[0060] <Additional Notes> A vehicle detection device (10) for detecting a type of vehicle traveling on a road (80), comprising: a detection point extraction unit (31) that extracts a plurality of detection points from a received signal obtained by reflection from a vehicle; A clustering processing unit (32) that groups a plurality of detection points according to features of the plurality of detection points; a variation information calculation unit (33) that calculates variation information of positions of a plurality of detection points grouped into one group; a vehicle type determination unit (34) that determines whether the vehicle is a large vehicle traveling alone or a plurality of small vehicles traveling in parallel based on the variation information; A vehicle detection device (10) comprising: [Explanation of symbols]

[0061] 10: Vehicle detection device 20: Radar 30: Signal processing section 31: Detection point extraction unit 32: Clustering processing unit 33: Variation information calculation unit 34: Vehicle type determination unit 40: Communications Department 80: Road 90c, 90c1, 90c2: small car 90t: large vehicle

Claims

1. A vehicle detection device that detects a type of vehicle traveling on a road, a detection point extraction unit that extracts a plurality of detection points from a received signal obtained by reflection from the vehicle; a clustering processing unit that groups the plurality of detection points according to features of the plurality of detection points; A variation information calculation unit that calculates variation information of positions of a plurality of detection points grouped into one group; a vehicle type determination unit that determines whether the vehicle is a large vehicle traveling alone or a plurality of small vehicles traveling in parallel based on the variation information; Equipped with the variation information calculation unit calculates, as the variation information, a first variation value in a width direction of the road and a second variation value in a traveling direction of the vehicle on the road; the vehicle type determination unit determines the vehicle as a plurality of small vehicles traveling side by side if the first variation value is equal to or greater than a first threshold value for determining a small vehicle and the second variation value is less than a second threshold value for determining a large vehicle, and determines the vehicle as a large vehicle traveling alone if the first variation value is equal to or greater than the first threshold value and the second variation value is equal to or greater than the second threshold value. Vehicle detection device.

2. The vehicle type determination unit determines that the vehicle is a small vehicle traveling alone when the first variation value is less than the first threshold value. The vehicle detection device of claim 1 .

3. The variation information calculation unit extracts a first detection point located at one end of the road in a width direction and a second detection point located at the other end of the road from a plurality of detection points grouped into one group, and calculates the length of the road in the width direction at the position of the first detection point and the position of the second detection point as the first variation value.

3. A vehicle detection device according to claim 1 or 2.

4. The variation information calculation unit extracts a third detection point located at one end side of the road in the traveling direction of the vehicle and a fourth detection point located at the other end side from the multiple detection points grouped into one group, and calculates the length of the road in the traveling direction of the vehicle at the position of the third detection point and the position of the fourth detection point as the second variation value. The vehicle detection device according to any one of claims 1 to 3.

5. A detection unit is provided which emits detection waves to the road and outputs a received signal. The vehicle detection device according to any one of claims 1 to 4.

6. A vehicle detection computer that detects the type of vehicle traveling on the road a detection point extraction step of extracting a plurality of detection points from a received signal obtained by reflection from the vehicle; a clustering process step of grouping the plurality of detection points according to features of the plurality of detection points; A variation information calculation step of calculating variation information of positions of the plurality of detection points grouped into one group; a vehicle type determination step of determining whether the vehicle is a large vehicle traveling alone or a plurality of small vehicles traveling in parallel based on the variation information; the variation information calculation step is a step of calculating, as the variation information, a first variation value in a width direction of the road and a second variation value in a traveling direction of the vehicle on the road; The vehicle type determination step is a step of determining that the vehicles are multiple small vehicles traveling side by side if the first variation value is equal to or greater than a first threshold value for determining a small vehicle and the second variation value is less than a second threshold value for determining a large vehicle, and determining that the vehicles are large vehicles traveling alone if the first variation value is equal to or greater than the first threshold value and the second variation value is equal to or greater than the second threshold value. Vehicle detection methods.

7. A vehicle detection computer detects the type of vehicle traveling on the road. a detection point extraction step of extracting a plurality of detection points from a received signal obtained by reflection from the vehicle; a clustering process step of grouping the plurality of detection points according to features of the plurality of detection points; A variation information calculation step of calculating variation information of positions of the plurality of detection points grouped into one group; a vehicle type determination step of determining whether the vehicle is a large vehicle traveling alone or a plurality of small vehicles traveling in parallel based on the variation information; the variation information calculation step is a step of calculating, as the variation information, a first variation value in a width direction of the road and a second variation value in a traveling direction of the vehicle on the road; The vehicle type determination step is a step of determining that the vehicles are multiple small vehicles traveling side by side if the first variation value is equal to or greater than a first threshold value for determining a small vehicle and the second variation value is less than a second threshold value for determining a large vehicle, and determining that the vehicles are large vehicles traveling alone if the first variation value is equal to or greater than the first threshold value and the second variation value is equal to or greater than the second threshold value. Vehicle detection program.

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