JP7050020B2 - Vehicle detection device, vehicle detection method, and program - Google Patents

Description

The present invention relates to a vehicle detection device, a vehicle detection method, and a program.

A technique for detecting a vehicle length is known (see, for example, Patent Document 1). In this technology, the vehicle length detecting device has a first sensor that detects the presence of the vehicle in the first position in the vehicle traveling direction on the roadway and a second position that is a predetermined distance downstream from the first position in the vehicle traveling direction. The second sensor that detects the presence of the vehicle in the vehicle, the distance between the first position and the second position, the time required for the vehicle to move within the distance, and the first sensor or the second sensor detects the vehicle. It is equipped with a processing device that calculates the vehicle length based on the time spent.

Japanese Unexamined Patent Publication No. 2008-180611

The vehicle length detection device described above detects the presence of a vehicle in a second position at a predetermined distance downstream from the first position in the vehicle traveling direction and a first sensor that detects the presence of the vehicle in the first position in the vehicle traveling direction. A large installation space is required to provide a second sensor for detection.
Since the vehicle length detecting device is often installed in a limited space, it is preferable that the vehicle length detecting device is miniaturized. Furthermore, the environment in which the vehicle length detection device is installed is required to be able to stably secure electric power. Further, since the vehicle length detection device is often installed at many points, low cost is required. Further, depending on the place where the vehicle length detection device is installed, a pedestrian or the like may pass in front of the sensor, so that the vehicle length detection device needs to be able to distinguish between a vehicle and an object other than the vehicle. The above applies not only to the vehicle length detection device but also to the vehicle detection device that detects the vehicle.
The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle detection device, a vehicle detection method, and a program that can be installed in a small space and can reduce false detection.

(1) One aspect of the present invention is to irradiate a first distance, which is a distance between a first position, which is a first end portion of a vehicle in the vehicle traveling direction, on a lane through which the vehicle passes, in an irradiation cycle. The second distance, which is the distance between the first distance measuring sensor detected by the above and the second position which is the second end of the vehicle on the upstream side or the downstream side in the vehicle traveling direction from the first position, is determined. Based on the second range-finding sensor detected by irradiating light in the irradiation cycle, the first distance detected by the first range-finding sensor, and the second distance detected by the second range-finding sensor. The first unit is provided with a vehicle detection unit that determines that a vehicle passing through the lane is detected when the first distance and the second distance are continuously equal to or less than the distance threshold value. The distance measurement sensor and the second distance measurement sensor are installed so that the radiation direction of the first distance measurement sensor and the radiation direction of the second distance measurement sensor form a predetermined angle, and the vehicle detection unit. Sets the number of times threshold in the irradiation cycle, the predetermined angle is θ, the radiation angle of the first distance measurement sensor is Φ, and the radiation angle of the second distance measurement sensor is Φ. Is Φ, the shortest length of the vehicle to be detected is Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first distance measuring sensor or the second distance measuring sensor is Hmax, and the above. When the measurement interval time of the first distance measuring sensor or the second distance measuring sensor is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
It is a vehicle detection device represented by .
(2) One aspect of the present invention is the vehicle detection device according to (1) above, wherein the vehicle detection unit has the number of times based on the irradiation cycle, the first distance, and the second distance. Set the threshold.
(3) One aspect of the present invention is the vehicle detection device according to the above (1) or (2), wherein the number threshold is TH, the irradiation cycle is T, and the first distance. Is d1, the second distance is d2, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the vehicle to be detected. When the shortest vehicle length is Lcmin, the maximum vehicle speed is Vmax, and max (d1, d2) represents the maximum value of d1 and d2.
TH = {Lcmin-2 x max (d1, d2) x sin (θ-Φ)} / Vmax x T
Represented by.

(4) One aspect of the present invention is a vehicle detection method executed by a vehicle detection device, wherein the first distance measuring sensor is the first end portion of the vehicle in the vehicle traveling direction on the lane through which the vehicle passes. The step of detecting the first distance, which is the distance between the first position, by irradiating light in the irradiation cycle, and the second distance measuring sensor on the upstream side or the downstream side in the vehicle traveling direction from the first position. The step of detecting the second distance, which is the distance between the second position, which is the second end of the vehicle, by irradiating light in the irradiation cycle, the first distance, and the second distance. Based on this, in the step of determining that a vehicle passing through the lane is detected when the first distance and the second distance are continuously equal to or less than the distance threshold, and in the irradiation cycle. It has a step of setting the number-of-times threshold, and the first range-finding sensor and the second range-finding sensor have a radiation direction of the first range-finding sensor and a radiation direction of the second range-finding sensor. It is installed so as to form a predetermined angle, and the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, and the radiation angle of the second distance measuring sensor is Φ. The shortest length of the vehicle to be detected is Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first distance measuring sensor or the second distance measuring sensor is Hmax, and the first distance measuring is performed. When the measurement interval time of the sensor or the second ranging sensor is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
It is a vehicle detection method represented by .

(5) In one aspect of the present invention, in the computer of the vehicle detection device, the first distance measuring sensor is located between the first position, which is the first end portion of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes. The step of detecting the first distance, which is a distance, by irradiating light in the irradiation cycle, and the second distance measuring sensor, the second end portion of the vehicle on the upstream side or the downstream side in the vehicle traveling direction from the first position. The second distance, which is the distance between the second position and the second position, is detected by irradiating light in the irradiation cycle, and the number of times threshold value or more is based on the first distance and the second distance. When the first distance and the second distance are continuously equal to or less than the distance threshold, the number of times threshold is set in the step of determining that a vehicle passing through the lane is detected and the irradiation cycle. The step is executed so that the first range-finding sensor and the second range-finding sensor make a predetermined angle between the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor. The predetermined angle is the shortest of the vehicle to be detected, where θ is the predetermined angle, Φ is the radiation angle of the first distance measurement sensor, and Φ is the radiation angle of the second distance measurement sensor. The vehicle length is Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, the first ranging sensor or the second measuring sensor. When the measurement interval time of the distance sensor is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
It is a program represented by .

(6) One aspect of the present invention irradiates light with an irradiation cycle for a first distance, which is a distance between a first position, which is a first end of a vehicle in the vehicle traveling direction, on a lane through which the vehicle passes. The second distance, which is the distance between the first distance measuring sensor detected by the above and the second position which is the second end of the vehicle on the upstream side or the downstream side in the vehicle traveling direction from the first position, is determined. The second distance measuring sensor detected by irradiating light in the irradiation cycle, the time change of the first distance detected by the first distance measuring sensor, and the second distance detected by the second distance measuring sensor. The first range-finding sensor and the second range-finding sensor are provided with a vehicle detection unit that detects the front surface or the rear surface of the vehicle passing through the lane based on any of the time changes of the above. The radiation direction of the first distance measurement sensor and the radiation direction of the second distance measurement sensor are installed so as to form a predetermined angle, and the predetermined angle is the first distance measurement with the predetermined angle as θ. The radiation angle of the sensor is Φ, the radiation angle of the second ranging sensor is Φ, the shortest length of the vehicle to be detected is Lcmin, the maximum speed of the vehicle is Vmax, and the vehicle and the first ranging sensor or When the maximum value of the vertical distance to the second ranging sensor is Hmax and the measurement interval time of the first ranging sensor or the second ranging sensor is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
It is a vehicle detection device represented by .
(7) One aspect of the present invention is the vehicle detection device according to (6) above, wherein the vehicle detection unit has either a time change of the first distance or a time change of the second distance. When it is equal to or less than the first time change threshold value, it is determined that the front surface of the vehicle has been detected.
(8) One aspect of the present invention is the vehicle detection device according to the above (6) or (7), wherein the vehicle detection unit has a time change of the first distance and a time change of the second distance. When any of the above is equal to or greater than the second time change threshold value, it is determined that the rear surface of the vehicle has been detected.
(9) One aspect of the present invention is the vehicle detection device according to any one of (6) to (8) above, wherein the vehicle detection unit is the first distance measuring sensor or the second distance measuring sensor. The time interval from the time when the sensor detects the distance to the front end on the right side of the vehicle to the time when the distance to the front end on the left side of the vehicle is detected, or the distance from the front end on the left side. It is determined whether or not the front surface of the vehicle is detected based on the time change at the time interval from the time when the vehicle is detected to the time when the distance between the vehicle and the front end portion on the right side of the vehicle is detected.
(10) One aspect of the present invention is the vehicle detection device according to any one of (6) to (9) above, wherein the vehicle detection unit is the first distance measuring sensor or the second distance measuring sensor. The time interval from the time when the sensor detects the distance from the rear end on the right side of the vehicle to the time when the distance from the rear end on the left side of the vehicle is detected, or the time interval with the rear end on the left side. Whether or not the rear surface of the vehicle is detected based on the time change in the time interval from the time when the distance between them is detected to the time when the distance between the vehicle and the rear end on the right side of the vehicle is detected. judge.

(11) One aspect of the present invention is a vehicle detection method executed by a vehicle detection device, wherein the first distance measuring sensor is the first end portion of the vehicle in the vehicle traveling direction on the lane through which the vehicle passes. The step of detecting the first distance, which is the distance between the first position, by irradiating light in the irradiation cycle, and the second distance measuring sensor on the upstream side or the downstream side in the vehicle traveling direction from the first position. The step of detecting the second distance, which is the distance between the second position, which is the second end of the vehicle, by irradiating light in the irradiation cycle, the time change of the first distance, and the second. The first distance measuring sensor and the second distance measuring sensor have a step of detecting the front surface or the rear surface of the vehicle passing through the lane based on either the time change of the distance. The radiation direction of the first distance measurement sensor and the radiation direction of the second distance measurement sensor are installed so as to form a predetermined angle, and the predetermined angle is the first distance measurement with the predetermined angle as θ. The radiation angle of the sensor is Φ, the radiation angle of the second ranging sensor is Φ, the shortest length of the vehicle to be detected is Lcmin, the maximum speed of the vehicle is Vmax, and the vehicle and the first ranging sensor or When the maximum value of the vertical distance to the second ranging sensor is Hmax and the measurement interval time of the first ranging sensor or the second ranging sensor is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
It is a vehicle detection method represented by .

(12) In one aspect of the present invention, in the computer of the vehicle detection device, the first distance measuring sensor is located between the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes. The step of detecting the first distance, which is a distance, by irradiating light in the irradiation cycle, and the second distance measuring sensor, the second end portion of the vehicle on the upstream side or the downstream side in the vehicle traveling direction from the first position. The step of detecting the second distance, which is the distance between the second position and the second position, by irradiating light in the irradiation cycle, the time change of the first distance, and the time change of the second distance. Based on any of these, the step of detecting the front surface or the rear surface of the vehicle passing through the lane is executed, and the first distance measuring sensor and the second distance measuring sensor are the first distance measuring sensor. The radiation direction of the second distance measuring sensor and the radiation direction of the second distance measuring sensor are installed so as to form a predetermined angle, the predetermined angle is θ, and the radiation angle of the first distance measuring sensor is Φ. The radiation angle of the second ranging sensor is Φ, the shortest length of the vehicle to be detected is Lcmin, the maximum speed of the vehicle is Vmax, and the vehicle and the first ranging sensor or the second ranging sensor. When the maximum value of the vertical distance to and from is Hmax and the measurement interval time of the first distance measuring sensor or the second distance measuring sensor is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
It is a program represented by .

According to the present invention, it is possible to provide a vehicle detection device, a vehicle detection method, and a program that can be installed in a small space and can reduce false detection.

It is a figure which shows an example of the vehicle detection system of the embodiment of this invention. It is a figure which shows an example of the vehicle detection apparatus which constitutes the vehicle detection system of the embodiment of this invention. It is a figure which shows the 1st example of the installation position of the distance measuring sensor of the vehicle detection apparatus of this invention. It is a figure which shows an example of the vehicle detection information. It is a figure which shows an example of the method which the vehicle detection apparatus constituting the vehicle detection system of the embodiment of this invention derives the number-of-times thresholds. It is a figure which shows the example 1 of the operation of the vehicle detection apparatus of the embodiment of this invention. It is a figure which shows the example 2 of the operation of the vehicle detection apparatus of the embodiment of this invention. It is a figure which shows the example 3 of the operation of the vehicle detection apparatus of the embodiment of this invention. It is a flowchart which shows an example of the operation of the vehicle detection apparatus of embodiment of this invention. It is a flowchart which shows an example of the operation of the vehicle detection apparatus of embodiment of this invention. It is a figure which shows the 2nd example of the installation position of the distance measuring sensor of the vehicle detection apparatus of this invention. It is a figure which shows the 2nd example of the dynamic determination method of the number-of-numbers thresholds of embodiment of this invention. It is a figure which shows the example 4 of the operation of the vehicle detection apparatus of the embodiment of this invention.

Next, the vehicle detection device, the vehicle detection method, and the program of the present embodiment will be described with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.
In all the drawings for explaining the embodiment, the same reference numerals are used for those having the same function, and the repeated description will be omitted.
Further, "based on XX" as used in the present application means "based on at least XX", and includes a case where it is based on another element in addition to XX. Further, "based on XX" is not limited to the case where XX is used directly, but also includes the case where XX is calculated or processed. "XX" is an arbitrary element (for example, arbitrary information).

(Embodiment)
(Vehicle detection system)
FIG. 1 is a diagram showing an example of a vehicle detection system according to an embodiment of the present invention. The vehicle detection system 1 of the present embodiment includes a vehicle detection device 100 and an external storage device 60. These devices are connected to each other via the communication network 50. The communication network 50 includes, for example, a radio base station, a Wi-Fi access point, a communication line, a provider, the Internet, and the like. The communication network 50 may include a local network in part.
The vehicle detection device 100 includes two ranging sensors (first ranging sensor, second ranging sensor). The vehicle detection device 100 is installed so that the light (beam) emitted by the first ranging sensor and the light emitted by the second ranging sensor pass over the road away from the road. The vehicle detection device 100 is installed so that the angle formed by the direction of the light emitted by the first ranging sensor and the direction of the light emitted by the second ranging sensor is 2θ. The angle 2θ between the direction of the light emitted by the first ranging sensor in the first cycle and the direction of the light irradiated by the second ranging sensor in the second cycle will be described later. The first range-finding sensor and the second range-finding sensor measure the distance between objects in different directions from each other.

The vehicle detection device 100 detects a vehicle based on the information indicating the first distance measured by the first distance measuring sensor and the information indicating the second distance measured by the second distance measuring sensor. Specifically, in the vehicle detection device 100, the number of times that both the first distance and the second distance are less than the distance threshold value based on the information indicating the first distance and the information indicating the second distance. When it is detected that the vehicle continues to exceed the threshold value, it is determined that the vehicle has been detected. That is, the vehicle detection device 100 has detected that both the first distance and the second distance are continuously below the distance threshold value for the number of times threshold value or more, and has detected the front surface or the rear surface of the vehicle. In this case, it is determined that the vehicle has passed the lane. Here, an example of the distance threshold value depends on the installation environment, but is preferably about 400 cm to 600 cm, for example.
When the vehicle detection device 100 determines that the vehicle has passed the lane, which of the first distance measuring sensor and the second distance measuring sensor detects the vehicle first. Based on this, the traveling direction of the vehicle is determined.
When the vehicle detection device 100 detects a vehicle, the vehicle detection identification information is information indicating that the vehicle is detected, information indicating the date and time when the vehicle is detected, and information indicating the traveling direction of the vehicle. And memorize in association with. The vehicle detection device 100 transmits the stored vehicle detection identification information, the information indicating the date and time when the vehicle was detected, and the information indicating the traveling direction of the vehicle to the external storage device 60. Next, the vehicle detection device 100 will be described in detail.

(Vehicle detection device)
FIG. 2 is a diagram showing an example of a vehicle detection device constituting the vehicle detection system according to the embodiment of the present invention.
The vehicle detection device 100 includes a distance measuring sensor 10, an information processing unit 20, a storage unit 30, and a communication unit 40. The information processing unit 20, the distance measuring sensor 10, the storage unit 30, and the communication unit 40 are connected by an internal bus so that information can be exchanged with each other.
The distance measuring sensor 10 includes a plurality of sensors. Here, as an example, a case where the range-finding sensor 10 includes two sensors, a first range-finding sensor 11 and a second range-finding sensor 12, will be described. The first range-finding sensor 11 and the second range-finding sensor 12 are at a predetermined height from the ground surface, and the direction of the light emitted by the first range-finding sensor 11 and the light emitted by the second range-finding sensor 12. It is installed so that the angle formed by the direction is 2θ (<180 degrees). In the present embodiment, as an example, the vehicle detection device 100 is installed so that the light emitted by the first ranging sensor 11 and the light emitted by the second ranging sensor 12 are horizontal to the ground surface. Continue explaining the case. Both the light emitted by the first ranging sensor 11 and the light emitted by the second ranging sensor 12 pass over the traveling route (laneway) on which the vehicle travels. An example of a predetermined height is about 20 cm to 40 cm.

Each of the first distance measuring sensor 11 and the second distance measuring sensor 12 is provided with a light source, and the light emitted from the light source receives the reflected light, which is the light reflected by hitting the object, by the light receiving element. .. The first distance measuring sensor 11 irradiates light in the first cycle, and derives a first distance between the first distance measuring sensor 11 and the object based on the reflected light received by the light receiving element. For example, the first distance measuring sensor 11 may derive the first distance by a triangular distance measuring formula that converts the image formation position of the light receiving element due to the change in distance into a distance, or the light receiving element may derive the first distance from the time when the light is irradiated. The first distance may be derived by a time-of-flight formula that measures the time until light is received and converts the measured time difference into a distance. The first distance measuring sensor 11 outputs information indicating the first distance to the information processing unit 20.
The second distance measuring sensor 12 irradiates light in the second cycle, and derives a second distance between the second distance measuring sensor 12 and the object based on the reflected light received by the light receiving element. The first cycle and the second cycle are the same, and the timing at which the first ranging sensor 11 irradiates light and the timing at which the second ranging sensor 12 irradiates light are synchronized. For example, the second distance measuring sensor 12 may derive the second distance by a triangular distance measuring formula that converts the image formation position of the light receiving element due to the change in distance into a distance, or the light receiving element may derive the second distance from the time when the light is irradiated. The second distance may be derived by a time-of-flight formula that measures the time until light is received and converts the measured time difference into a distance. The second distance measuring sensor 12 outputs information indicating the second distance to the information processing unit 20.

Here, the angle 2θ formed by the direction of the light emitted by the first ranging sensor 11 and the direction of the light emitted by the second ranging sensor 12 will be described.
The angle 2θ needs to be appropriately set for the vehicle detection unit 21 to detect the vehicle. If the angle 2θ is too large, the distance between the position of the light emitted by the first distance measuring sensor 11 and the position of the light emitted by the second distance measuring sensor 12 on the traveling route becomes long, so that the traveling route is set to the vehicle. When the vehicle travels, both the first distance and the second distance do not fall below the distance threshold. Therefore, even when the vehicle travels on the travel route, the vehicle detection unit 21 cannot determine that the vehicle has passed the travel route.
On the contrary, when the angle 2θ is too small, the distance between the position of the light emitted by the first ranging sensor 11 and the position of the light emitted by the second ranging sensor 12 on the traveling route becomes short, so that the traveling route is shortened. Even when an object having a shorter overall length than a vehicle such as a pedestrian passes through, both the first distance and the second distance are less than the distance threshold. Therefore, even if an object having a short overall length passes through the traveling route, it is erroneously determined that the vehicle has passed.
Therefore, as shown below, an angle 2θ between the direction of the light emitted by the first ranging sensor 11 and the direction of the light irradiated by the second ranging sensor 12 is set.

FIG. 3 is a diagram showing a first example of the installation position of the distance measuring sensor of the vehicle detection device according to the embodiment of the present invention. In the example shown in FIG. 3, the direction of the light emitted by the first ranging sensor 11 is an angle θ clockwise when the direction perpendicular to the traveling route is used as a reference, and the second ranging sensor 12 has an angle θ. The direction of the emitted light is an angle θ in the counterclockwise direction.
As shown in FIG. 3, the radiation angle of the first distance measuring sensor 11 is Φ, and the radiation angle of the second distance measuring sensor 12 is Φ. That is, when the normal direction of the laser irradiation port of the first distance measuring sensor 11 is used as a reference, the laser beam is irradiated in the range of the angle Φ clockwise and the angle −Φ counterclockwise from the reference. To. Further, when the normal direction of the laser irradiation port of the second ranging sensor 12 is used as a reference, the laser beam is irradiated in the range of the angle Φ clockwise and the angle −Φ counterclockwise from the reference. To.
Further, as detection targets, the vehicle length of the vehicle 70 having the shortest expected vehicle length is Lcmin, the maximum speed of the assumed vehicle 70 is Vmax, and the longest vertical distance from the vehicle detection device 100 of the vehicle 70 passing through the traveling route. Hmax, and T is the measurement interval time, which is the time interval at which each of the first distance measuring sensor 11 and the second distance measuring sensor 12 measures the distance by irradiating the laser.
By setting the angle θ based on the equation (1), when the vehicle 70 passes through the traveling route, the angle 2θ can be maximized while correctly determining the passing vehicle as a vehicle.

θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax} (1)

In this case, when the vehicle having the total length Lh (Lh <Lcmin) and the object other than the vehicle travel in parallel with the road, the vertical distance along the direction perpendicular to the traveling route from the distance measuring sensor 10 is Lh /. If it is farther than 2 × tan (θ−Φ), it is not determined to be a vehicle. Return to FIG. 2 and continue the explanation.

The storage unit 30 is realized by, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), a flash memory, or a hybrid storage device in which a plurality of these are combined. The storage unit 30 stores the program 31 executed by the information processing unit 20 and the application 32. Further, the vehicle detection information 33 is stored in the storage unit 30.
The program 31 is, for example, an operating system, located between the user and the application program and the hardware, and provides a standard interface for the user and the application program while being efficient for each resource such as the hardware. Management.
The application 32 causes the first distance measuring sensor 11 to measure the first distance, which is the distance between the object and the first distance measuring sensor 11. The application 32 causes the second ranging sensor 12 to measure the second distance, which is the distance between the object and the second ranging sensor 12. The application 32 causes the vehicle detection device 100 to detect a vehicle based on the information indicating the first distance measured by the first distance measuring sensor and the information indicating the second distance measured by the second distance measuring sensor. The application 32 sets the vehicle detection device 100 at a first time, which is the time when the first distance measuring sensor measures the first distance, and a second time, which is the time when the second distance measuring sensor measures the second distance. Based on this, the traveling direction of the vehicle is derived. The application 32 causes the vehicle detection device 100 to generate vehicle detection identification information, and stores the generated vehicle detection identification information, information indicating the date and time when the vehicle is detected, and information indicating the traveling direction of the vehicle in association with each other. .. The application 32 causes the vehicle detection device 100 to transmit the stored vehicle detection identification information, the information indicating the date and time when the vehicle is detected, and the information indicating the traveling direction of the vehicle to the external storage device 60. ..

(Vehicle detection information)
The vehicle detection information 33 is table-type information in which the vehicle detection identification information, the information indicating the date and time when the vehicle is detected, and the information indicating the traveling direction of the vehicle are associated with each other.
FIG. 4 is a diagram showing an example of vehicle detection information. In the example shown in FIG. 4, the vehicle detection identification information "A0001", the detection date and time "** month ** day ** hour ** minute", and the traveling direction "right → left" are associated with each other, and the vehicle detection identification information ""A0002", the detection date and time "00: 00: 00: 00", and the traveling direction "left → right" are associated with each other. Returning to FIG. 2, the explanation will be continued.
All or part of the information processing unit 20 is a functional unit (hereinafter referred to as software) realized by, for example, a processor such as a CPU (Central Processing Unit) executing a program 31 and an application 32 stored in the storage unit 30. It is called a functional unit). All or part of the information processing unit 20 may be realized by hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), or FPGA (Field-Programmable Gate Array), and is a software function. It may be realized by a combination of a unit and hardware.
The information processing unit 20 has, for example, a vehicle detection unit 21 and a storage processing unit 23.
The vehicle detection unit 21 acquires information indicating the first distance measured by the first distance measuring sensor 11 and information indicating the second distance measured by the second distance measuring sensor 12, and indicates the acquired first distance. The vehicle is detected based on the information and the information indicating the second distance. When the first distance is less than the distance threshold value, the vehicle detection unit 21 determines that an object exists in front of the first distance measuring sensor 11. When the second distance is less than the distance threshold value, the vehicle detection unit 21 determines that an object exists in front of the second distance measurement sensor 12. The vehicle detection unit 21 determines that the vehicle was present when it was detected that the state in which both the first distance and the second distance were less than the distance threshold value was continuously continued for the number of times threshold value or more. That is, when the vehicle detection unit 21 detects that both the first distance and the second distance are continuously below the distance threshold value for the number of times threshold value or more, the vehicle travels on the travel route (road). ) Has passed.

The vehicle detection unit 21 updates by setting the number threshold value at a predetermined cycle. If the number-of-times threshold value is a fixed value, depending on the number-of-times threshold value to be set, if an object other than the vehicle passes near the vehicle detection device 100, the object may be erroneously determined as a vehicle. When a vehicle passes far away from the vehicle detection device 100, it may not be possible to determine that the vehicle is a vehicle.
On the other hand, even if the same object passes near the sensor, the number of simultaneous detections is large, and when the same object passes far away, the number of simultaneous detections is small. Therefore, the vehicle detection unit 21 sets the number thresholds to the first distance and the second. Dynamically set (determine) based on the distance. Hereinafter, the explanation will be continued on the assumption that the vehicle is moving in a straight line at a constant velocity. However, it can be applied even when the vehicle does not move in a straight line at a constant velocity.
FIG. 5 is a diagram showing an example of a method in which a vehicle detection device constituting the vehicle detection system according to the embodiment of the present invention derives a number threshold value.
In FIG. 5, the number of times threshold is TH, the vehicle length of the vehicle 70 having the shortest vehicle length assumed as the detection target is Lcmin, the maximum speed of the assumed vehicle 70 is Vmax, and the first distance measuring sensor 11 is used. The measurement interval time, which is the time interval for measuring the distance by irradiating each of the second distance measuring sensors 12 with a laser, is T, and the average value of the first distance while simultaneous detection is occurring is d1. Let the average value of the distance be d2. The measurement interval time T has the same first period.
At this time, the vehicle passing in front of the vehicle detection device 100 is simultaneously detected by the two sensors for a time of at least {Lcmin-2 × max (d1, d2) × sin (θ−Φ)} / Vmax. Here, max (d1, d2) represents the maximum value of d1 and d2. The reason for adopting the maximum values of d1 and d2 is that when the first distance measuring sensor 11 and the second distance measuring sensor 12 simultaneously detect the vehicle 70, the first distance measuring sensor 11 or the second distance measuring sensor 12 is used. This is to derive a threshold value capable of determining whether or not the vehicle 70 is passing even when an object other than the vehicle 70 blocks the front of either of the twelve. By adopting the maximum values of d1 and d2, the number-of-times threshold value TH can be determined based on the equation (2).

TH = {Lcmin-2max (d1, d2) x sin (θ-Φ)} / Vmax x T (2)

In an environment where people, bicycles, etc. frequently pass in front of the vehicle detection device 100, a plurality of objects other than the vehicle 70 pass in front of the first range-finding sensor 11 and the second range-finding sensor 12 at the same time. Situations can occur. In such a case, the state in which both the first distance and the second distance are less than the distance threshold value (simultaneous detection) may be continuously erroneously determined as a vehicle at least the number threshold value TH. For such a problem, the vehicle detection device 100 determines the vehicle by paying attention to the vehicle width peculiar to the vehicle.
The vehicle detection unit 21 detects the first distance between the tip portions, which is the distance between the front end portion of the vehicle 70 detected by the first distance measuring sensor 11, and the first distance between the tip portions, which is the time between the tip portions. 1 Acquire the distance detection time t1. The vehicle detection unit 21 detects the distance between the tip portions, which is the time when the second distance between the tip portions, which is the distance between the front end portion of the vehicle detected by the second distance measuring sensor 12, and the second distance between the tip portions, are detected. The second time t2 is acquired.
The vehicle detection unit 21 detects the first distance between the rear ends and the first distance between the rear ends, which is the distance between the rear ends of the vehicle 70 detected by the first distance measuring sensor 11. The first time t3 for detecting the distance between the ends is acquired. The vehicle detection unit 21 is the time when the second distance between the rear ends, which is the distance between the rear end of the vehicle detected by the second distance measuring sensor 12, and the second distance between the rear ends, are detected. The second time t4 for detecting the inter-unit distance is acquired.

A process of determining the presence of the front surface of the vehicle 70 by the vehicle detection unit 21 will be described with reference to FIGS. 6 to 8.
FIG. 6 is a diagram showing an example 1 of the operation of the vehicle detection device according to the embodiment of the present invention.
FIG. 7 is a diagram showing Example 2 of the operation of the vehicle detection device according to the embodiment of the present invention.
FIG. 8 is a diagram showing an example 3 of the operation of the vehicle detection device according to the embodiment of the present invention.
FIG. 6 shows the position of the vehicle 70 at the first distance detection time t1 between the tips, FIG. 7 shows the position of the vehicle 70 at the time tw, and FIG. 8 shows the vehicle at the second distance detection time t2 between the tips. The position of 70 is shown. The explanation will be continued assuming that the time tw is a time after the first distance detection time t1 between the tip portions and the second time t2 for detecting the distance between the tip portions is a time after the time tw.
Here, Φ is assumed to be small enough to be ignored. Since the vehicle 70 has a vehicle width as compared with a person or a bicycle, the first distance measuring sensor 11 moves the front surface of the vehicle 70 from the first distance detection time t1 between the tips to the time tw. Detect. Therefore, the first distance measured by the first distance measuring sensor 11 is greatly reduced. The vehicle detection unit 21 determines whether or not the vehicle 70 is in front of the vehicle detection device 100 based on the change in the first distance based on the information indicating the first distance measured by the first distance measurement sensor. judge.
In order to determine the decrease in the first distance measured by the first distance measuring sensor 11, the time range of the determination target, that is, the time interval from the first distance detection time t1 between the tip portions to tw is determined. The time required for the vehicle 70 to move from the position shown in FIG. 6 to the position shown in FIG. 8 is the second time for detecting the distance between the tips and the first time t1 for detecting the distance between the tips.
On the other hand, the mileage when the vehicle 70 moves from the position shown in FIG. 6 to the position shown in FIG. 7 is Wtan θ, where W is the vehicle width of the vehicle 70. Further, the maximum mileage when the vehicle 70 moves from the position shown in FIG. 7 to the position shown in FIG. 8 is 2 × max (d1, d2) × sin θ. Here, max (d1, d2) represents the maximum value of d1 and d2 as described above.
Here, the maximum values of d1 and d2 are adopted by the vehicle 70 with the first range-finding sensor 11 and the second range-finding sensor 12, as in the case of dynamically determining the number-of-times threshold value described above. Appropriate when an object other than the vehicle 70 blocks the front of either the first distance measuring sensor 11 or the second distance measuring sensor 12 when the two sensors simultaneously detect the vehicle 70. This is to make a proper judgment.
From the above, the equation (3) holds.

width_time (τ) = τWtanθ / {2max (d1, d2) sinθ + Wtanθ} (3)

From the formula (3), tw = t1 + width_time (t2-t1) can be obtained.
Further, the vehicle detection unit 21 acquires the information indicating the first distance measured by the first distance measuring sensor 11 and the information indicating the second distance measured by the second distance measuring sensor 12, and the acquired first distance. Based on the information indicating the second distance and the information indicating the second distance, the total distance, which is the total value of the first distance and the second distance, is derived.
The first distance measuring sensor 11 detects the front surface of the vehicle 70 from the first distance detection time t1 between the tip portions to the first distance detection time t1 + width_time (t2-t1) between the tip portions. In other words, the time range from the time when the first distance measuring sensor 11 detects the distance from the front end on the right side of the vehicle 70 to the time when the distance from the front end on the left side of the vehicle 70 is detected ( During the interval), the front surface of the vehicle 70 is detected.
If the vehicle 70 travels from left to right, the front end on the right side of the vehicle 70 is determined from the time when the second distance measuring sensor 12 detects the distance between the front end on the left side of the vehicle 70 and the front end on the left side of the vehicle 70. It means that the front surface of the vehicle 70 is detected during the time range (interval) up to the time when the distance between the vehicle and the vehicle is detected.
That is, from the time when the first distance measuring sensor 11 or the second distance measuring sensor 12 detects the distance from the front end on the right side of the vehicle 70, the distance from the front end on the left side of the vehicle 70 is detected. The front surface of the vehicle 70 during the time range from the time when the distance to the right front end of the vehicle 70 is detected to the time when the distance to the right front end of the vehicle 70 is detected. Will be detected.
The vehicle detection unit 21 is based on the change in the first distance measured by the first distance measuring sensor 11 in the time range from the first distance detection time t1 between the tip portions to the first distance detection time t1 + width_time (t2-t1) between the tip portions. , It is determined whether or not the front surface of the vehicle 70 is detected.
In the time range from the first distance detection time t1 between the tip portions to the first distance detection time t1 + width_time (t2-t1) between the tip portions, the front surface of the vehicle 70 and the first distance measuring sensor 11 change with the passage of time. The distance between them is expected to decrease. Therefore, in the vehicle detection unit 21, the time change of the first distance in the time range from the first distance detection time t1 between the tip portions to the first distance detection time t1 + width_time (t2-t1) between the tip portions is equal to or less than the time change threshold value. In a certain case, it is determined that the front surface of the vehicle 70 is detected.
Specifically, the vehicle detection unit 21 divides the time range to be determined on the front surface of the vehicle 70 into a plurality of time zones. The vehicle detection unit 21 derives statistical values such as the average value of the first distances obtained in each of the plurality of time zones in which the time range to be determined on the front surface of the vehicle 70 is divided. Here, the case where the vehicle detection unit 21 derives the average value of the first distance will be continued. The vehicle detection unit 21 determines whether the derived average value of the first distance is continuously reduced by a difference of the distance threshold value THw or more.
The vehicle detection unit 21 determines that the front surface of the vehicle 70 is not detected when the average value of the derived first distances does not continuously decrease by a difference of the distance threshold value THw or more. The vehicle detection unit 21 determines that the front surface of the vehicle 70 has been detected when the average value of the derived first distances continuously decreases by a difference of the distance threshold value THw or more.

The above has described the case where the front surface of the vehicle 70 is detected, but the case where the rear surface of the vehicle 70 is detected can also be applied. It is assumed that the position of the vehicle 70 at the rear end distance detection first time t3, the position of the vehicle 70 at the time tw, and the position of the vehicle 70 at the rear end distance detection second time t4. The explanation will be continued assuming that the time tw is a time after the first time t3 for detecting the distance between the rear ends and the second time t4 for detecting the distance between the rear ends is a time after the time tw. Similar to the case of detecting the front surface of the vehicle 70, tw = t4-width_time (t4-t3) is obtained.
The second distance measuring sensor 12 detects the rear surface of the vehicle 70 from the second time t4-width_time (t4-t3) for detecting the distance between the rear ends to the second time t4 for detecting the distance between the rear ends. become. In other words, the time from the time when the second distance measuring sensor 12 detects the distance from the rear end on the left side of the vehicle 70 to the time when the distance from the front end on the right side of the vehicle 70 is detected. During the range (interval), the rear surface of the vehicle 70 is detected.
Further, if the vehicle 70 travels from left to right, the first distance measuring sensor 11 is on the left side of the vehicle 70 from the time when the distance between the first distance measuring sensor 11 and the rear end portion on the right side of the vehicle 70 is detected. It means that the rear surface of the vehicle 70 is detected during the time range (interval) up to the time when the distance to the rear end is detected.
That is, from the time when the first distance measuring sensor 11 or the second distance measuring sensor 12 detects the distance from the rear end portion on the right side of the vehicle 70, the distance from the rear end portion on the left side of the vehicle 70 is calculated. During the time interval between the time range to the detected time or the time when the distance from the rear end on the left side is detected to the time when the distance from the rear end on the right side of the vehicle 70 is detected. This means that the rear surface of the vehicle 70 is being detected.
The vehicle detection unit 21 is the first measured by the first distance measuring sensor 11 in the time range from the second time t4-width_time (t4-t3) for detecting the distance between the rear ends to the second time t4 for detecting the distance between the rear ends. From the change in distance, it is determined whether or not the rear surface of the vehicle 70 is detected.
In the time range from the second time t4-width_time (t4-t3) for detecting the distance between the rear ends to the second time t4 for detecting the distance between the rear ends, the rear surface of the vehicle 70 and the second distance measurement are performed with the passage of time. The distance to the sensor 12 is expected to increase. Therefore, in the vehicle detection unit 21, the time change of the first distance in the time range from the second time t4-width_time (t4-t3) for detecting the distance between the rear ends to the second time t4 for detecting the distance between the rear ends is time. When it is equal to or greater than the change threshold, it is determined that the rear surface of the vehicle 70 is detected.
Specifically, the vehicle detection unit 21 divides the time range to be determined on the rear surface of the vehicle 70 into a plurality of time zones. The vehicle detection unit 21 derives statistical values such as the average value of the second distances obtained in each of the plurality of time zones in which the time range to be determined on the rear surface of the vehicle 70 is divided. Here, the case where the vehicle detection unit 21 derives the average value of the second distance will be continued. The vehicle detection unit 21 determines whether the average value of the derived second distance is continuously increased by a difference of the distance threshold value THw or more.
The vehicle detection unit 21 determines that the rear surface of the vehicle 70 has not been detected when the average value of the derived second distance does not continuously increase by a difference of the distance threshold value THw or more. The vehicle detection unit 21 determines that the rear surface of the vehicle 70 has been detected when the average value of the derived second distance continuously increases by a difference of the distance threshold value THw or more.

When the vehicle detection unit 21 determines that the vehicle has passed the travel route (lane), the vehicle detection unit 21 has a first time, which is the time when the first distance measurement sensor 11 measures the first distance, and a second distance measurement sensor 12. Derives the traveling direction of the vehicle based on the second time, which is the time when the second distance is measured.
Specifically, when the first time is before the second time, the vehicle detection unit 21 sets the traveling direction of the vehicle from the installation position of the first distance measurement sensor 11 to the installation of the second distance measurement sensor 12. The direction toward the position (left direction in FIG. 3). That is, in the vehicle detection unit 21, of the first distance and the second distance, the first distance becomes less than the distance threshold before the second distance, and then the first distance becomes the distance before the second distance. When the distance exceeds the threshold value, it is determined that the vehicle is traveling in the direction from the first distance measuring sensor 11 to the second distance measuring sensor 12.
Further, when the second time is before the first time, the vehicle detection unit 21 directs the traveling direction of the vehicle from the installation position of the second distance measurement sensor 12 to the installation position of the first distance measurement sensor 11. The direction (right direction in FIG. 3). That is, in the vehicle detection unit 21, of the second distance and the first distance, the second distance becomes less than the distance threshold before the first distance, and then the second distance becomes the distance before the first distance. When the distance exceeds the threshold value, it is determined that the vehicle is traveling in the direction from the second distance measuring sensor 12 to the first distance measuring sensor 11.
When it is determined that the vehicle has passed the travel route, the vehicle detection unit 21 generates vehicle detection identification information, the generated vehicle detection identification information, information indicating the date and time when the vehicle has passed the travel route, and the vehicle. The vehicle detection information associated with the information indicating the traveling direction is output to the storage processing unit 23.
The storage processing unit 23 acquires the vehicle detection information output by the vehicle detection unit 21, and stores the acquired vehicle detection information in the vehicle detection information 33 of the storage unit 30. The storage processing unit 23 includes the acquired vehicle detection information, creates vehicle detection notification information destined for the external storage device 60, and outputs the created vehicle detection notification information to the communication unit 40.
The communication unit 40 acquires the vehicle detection notification information output by the storage processing unit 23, and transmits the acquired vehicle detection notification information to the external storage device 60.

(Operation of vehicle detection device)
FIG. 9 is a flowchart showing an example of the operation of the vehicle detection device according to the embodiment of the present invention. 9 shows, as an example, a direction in which the vehicle detection device 100 moves from the installation position of the first distance measurement sensor 11 to the installation position of the second distance measurement sensor 12 (left direction in FIG. 3) and the second distance measurement sensor 12. The process of determining whether or not the vehicle has passed is shown in either the direction from the installation position of the first distance measuring sensor 11 toward the installation position of the first distance measuring sensor 11 (right direction in FIG. 3).
(Step S1)
The vehicle detection unit 21 of the information processing unit 20 resets the count value and the total distance.
(Step S2)
The first distance measuring sensor 11 detects the first distance and outputs information indicating the detected first distance to the information processing unit 20. The second distance measuring sensor 12 detects the second distance and outputs information indicating the detected second distance to the information processing unit 20.
(Step S3)
The vehicle detection unit 21 of the information processing unit 20 has acquired and acquired the information indicating the first distance output by the first distance measurement sensor 11 and the information indicating the second distance output by the second distance measurement sensor 12. Based on the information indicating the first distance and the information indicating the second distance, it is determined whether or not both the first distance and the second distance are equal to or less than the distance threshold. If either or both of the first distance and the second distance is not equal to or less than the distance threshold value, the process returns to step S1.
(Step S4)
When the vehicle detection unit 21 determines that both the first distance and the second distance are equal to or less than the distance threshold value, the vehicle detection unit 21 increases the count value and the total distance.
(Step S5)
The first distance measuring sensor 11 detects the first distance and outputs information indicating the detected first distance to the information processing unit 20. The second distance measuring sensor 12 detects the second distance and outputs information indicating the detected second distance to the information processing unit 20.

(Step S6)
The vehicle detection unit 21 of the information processing unit 20 has acquired and acquired the information indicating the first distance output by the first distance measurement sensor 11 and the information indicating the second distance output by the second distance measurement sensor 12. Based on the information indicating the first distance and the information indicating the second distance, it is determined whether or not both the first distance and the second distance are equal to or less than the distance threshold. When the vehicle detection unit 21 determines that both the first distance and the second distance are equal to or less than the distance threshold value, the vehicle detection unit 21 returns to step S4.
(Step S7)
When either or both of the first distance and the second distance is not equal to or less than the distance threshold value, the vehicle detection unit 21 determines whether or not both the first distance and the second distance are larger than the distance threshold value. If either the first distance or the second distance is smaller than the distance threshold position, the process returns to step S5.
(Step S8)
When both the first distance and the second distance are larger than the distance threshold position, the vehicle detection unit 21 determines whether or not the count value is equal to or greater than the number of times threshold value. If the count value is less than the number threshold value, the process returns to step S1.
(Step S9)
The vehicle detection unit 21 determines whether or not the front surface or the rear surface of the vehicle 70 has been detected. If the front surface and the rear surface of the vehicle 70 have not been detected, the process returns to step S1.
(Step S10)
When the vehicle detection unit 21 determines that the front surface or the rear surface of the vehicle 70 has been detected, the vehicle detection unit 21 determines that the vehicle 70 has passed in front of the vehicle detection device 100.

FIG. 10 is a flowchart showing an example of the operation of the vehicle detection device according to the embodiment of the present invention. FIG. 10 shows the details of the process of step S9 of FIG.
(Step S11)
The vehicle detection unit 21 derives a time range to be determined between the front surface and the rear surface of the vehicle 70. The vehicle detection unit 21 derives the first distance detection time t1 + width_time (t2-t1) between the tip portions from the first distance detection time t1 between the tip portions, which is the time range of the determination target on the front surface of the vehicle 70. The vehicle detection unit 21 derives the rear end distance detection second time t4 from the rear end distance detection second time t4-width_time (t4-t3), which is the time range of the determination target on the rear surface of the vehicle 70.
(Step S12)
The vehicle detection unit 21 divides the time range to be determined between the front surface of the vehicle 70 and the rear surface of the vehicle 70 into a plurality of time zones.
(Step S13)
The vehicle detection unit 21 derives the average value of the first distances obtained in each of the plurality of time zones in which the time range to be determined on the front surface of the vehicle 70 is divided.
(Step S14)
The vehicle detection unit 21 derives statistical values such as the average value of the second distances obtained in each of the plurality of time zones in which the time range to be determined on the rear surface of the vehicle 70 is divided. Here, as an example of statistical values, the case of deriving the average value will be described.
(Step S15)
In the vehicle detection unit 21, the average value of the derived first distance continuously decreases by a difference of the distance threshold THw or more, or the average value of the derived second distance continuously decreases by the difference of the distance threshold THw or more. Determine if it is increasing. When the derived average value of the first distance is not continuously decreased by the difference of the distance threshold THw or more, and the average value of the derived second distance is not continuously increased by the difference of the distance threshold THw or more. , Return to step S11.
(Step S16)
In the vehicle detection unit 21, the average value of the derived first distance is continuously decreased by the difference of the distance threshold THw or more, or the average value of the derived second distance is continuously decreased by the difference of the distance threshold THw or more. When the number is increasing, it is determined that the front surface of the vehicle 70 or the rear surface of the vehicle 70 is detected.

In the above-described embodiment, in the setting example of the angle 2θ, the direction of the light emitted by the first ranging sensor 11 is the angle θ in the clockwise direction when the direction perpendicular to the traveling route is used as a reference, and the second Although the case where the direction of the light emitted by the distance measuring sensor 12 is an angle θ in the counterclockwise direction has been described, the present invention is not limited to this example. For example, when the direction perpendicular to the travel route is used as a reference, the direction of the light emitted by the first ranging sensor 11 is an angle θ + α in the clockwise direction, and the direction of the light emitted by the second ranging sensor 12 is , It can also be applied to the case where the angle is θ−α counterclockwise.
FIG. 11 is a diagram showing a second example of the installation position of the distance measuring sensor of the vehicle detection device according to the embodiment of the present invention.
Similar to FIGS. 3 and 5, the radiation angle of the first distance measuring sensor 11 is Φ, and the radiation angle of the second distance measuring sensor 12 is Φ. Further, the length of the vehicle 70 having the shortest expected length is Lcmin, the maximum speed of the assumed vehicle 70 is Vmax, the longest vertical distance of the vehicle 70 passing through the traveling route from the vehicle detection device 100 is Hmax, and the first. Let T be the measurement interval time, which is the time interval in which each of the distance measuring sensor 11 and the second distance measuring sensor 12 measures the distance by irradiating the laser.
Let α be the maximum angle of the travel route with respect to the vehicle detection device 100. That is, when the direction perpendicular to the traveling route is used as a reference, the direction of the light emitted by the first ranging sensor 11 is an angle θ + α in the clockwise direction, and the direction of the light emitted by the second ranging sensor 12 is The direction is an angle θ−α counterclockwise.
The maximum value of the length D from the front end portion to the rear end portion of the vehicle side surface detected by the first distance measuring sensor 11 and the second distance measuring sensor 12 is represented by the equation (1a).

D = Hmax x sin (θ-φ) x (1 / cos (θ-φ-α) + 1 / cos (θ-φ + α)) (1a)

From the equation (1a), by maximizing θ while satisfying D ≦ Lcmin−Vmax × T, it is possible to correctly determine that the vehicle is a vehicle when the vehicle passes, and to detect an object other than the vehicle. An object other than a vehicle having a total length Lh (Lh <Lcmin) is not determined to be a vehicle if the vertical distance from the distance measuring sensor 10 is farther than Lh / 2 × tan (θ−Φ).
FIG. 12 is a diagram showing a second example of a method for dynamically determining the number of times threshold value according to the embodiment of the present invention.
In the same parameters as in FIG. 3, the angle of the traveling route with respect to the vehicle detection device 100 is α. At this time, the vehicle passing in front of the vehicle detection device 100 is simultaneously detected by the two sensors for a time of at least {Lcmin-2 × max (d1, d2) × sin (θ−Φ) / cosα} / Vmax. .. From this, the number threshold TH can be determined based on the equation (4).

TH = {Lcmin-2max (d1, d2) sin (θ-Φ) / cosα} / VmaxT (4)

FIG. 13 is a diagram showing an example 4 of the operation of the vehicle detection device according to the embodiment of the present invention. In the same parameters as those in FIGS. 6 to 8, the angle of the traveling route with respect to the vehicle detection device 100 is defined as α. Also in FIG. 11, similarly to FIGS. 6 to 8, the distance traveled by the vehicle 70 between the first distance detection time t1 and the time tw between the tip portions is W × tan (θ + α), and the tip is from the time tw. During the second time t2 of inter-part distance detection, the maximum distance traveled by the vehicle 70 is 2max (d1, d2) sinθ / cosα.
From the above, the equation (5) holds.

width_time (τ) = τ × W × tan (θ + α) / {2 × max (d1, d2) sinθ / cosα + W × tan (θ + α)} (5)

From equation (5), tw = t1 + width_time (t2-t1) can be obtained.
The first distance measuring sensor 11 detects the front surface of the vehicle 70 in a time range from the first distance detection time t1 between the tip portions to the first distance detection time t1 + width_time (t2-t1) between the tip portions. ..
In the case of detecting the rear surface of the passing vehicle 70 as well as the case of detecting the front surface of the vehicle 70, the second distance measuring sensor 12 detects the distance between the rear ends at the second time t4-width_time (t4-t3). Since the rear surface of the vehicle 70 is detected during the second time t4 of the distance detection between the rear ends, the vehicle detection unit 21 starts from the second time t4-width_time (t4-t3) of the distance detection between the rear ends. Distance detection between rear ends In the time range of the second time t4, it can be determined whether or not the rear surface of the vehicle 70 has been detected from the change in the second distance measured by the second distance measuring sensor 12.
However, in FIG. 11, when θ ≦ α, the rear surface of the vehicle 70 cannot be detected, and when α ≦ −θ, the front surface of the vehicle 70 cannot be detected, so that the front surface and the rear surface of the vehicle 70 cannot be detected. When both are detected, it is necessary to satisfy at least -θ <α <θ.

In the above-described embodiment, the case where the vehicle detection device 100 detects whether or not the vehicle is traveling has one lane has been described, but the present invention is not limited to this example. For example, by setting a plurality of distance threshold values, the vehicle detection device 100 may detect a vehicle traveling in a plurality of lanes in parallel.
In the above-described embodiment, the case where the first range-finding sensor 11 and the second range-finding sensor 12 are installed at a predetermined height such as about 20 cm to 40 cm from the ground surface has been described, but the present invention is limited to this example. not. For example, the first range-finding sensor 11 and the second range-finding sensor 12 may be installed at a height of 2 m to 3 m from the ground surface, or may be installed in the ground. By installing the first range-finding sensor 11 and the second range-finding sensor 12 at a height of 2 m to 3 m from the ground surface, there are no obstacles as compared with the case where the first range-finding sensor 11 and the second range-finding sensor 12 are installed at a height of 20 cm to 40 cm from the ground surface. Is expected, so false positives can be reduced.
In the above-described embodiment, the case where the vehicle detection device 100 updates by setting the number-of-times threshold value at a predetermined cycle and the case where the front surface or the rear surface of the vehicle 70 is detected has been described, but the present invention is not limited to this example. For example, the vehicle detection device 100 updates by setting the number-of-times threshold value at a predetermined cycle, but may not detect the front surface or the rear surface of the vehicle 70.
Further, the vehicle detection device 100 may detect the front surface or the rear surface of the vehicle 70 with the number threshold value set to a fixed value. That is, the vehicle detection device 100 may update by setting the number-of-times threshold value at a predetermined cycle, or may detect either the front surface or the rear surface of the vehicle 70.

According to the vehicle detection device 100 of the embodiment, the vehicle detection device 100 is a first distance which is a distance from a first position which is a first end portion of the vehicle in the vehicle traveling direction on the lane through which the vehicle 70 passes. The distance between the first distance measuring sensor 11 that detects by irradiating light in the irradiation cycle and the second position, which is the second end of the vehicle on the upstream side or the downstream side of the vehicle traveling direction from the first position. The second distance measuring sensor 12 that detects the second distance by irradiating light in the irradiation cycle, the first distance detected by the first distance measuring sensor 11, and the second distance measuring sensor detected. A vehicle detection unit 21 for determining that a vehicle passing through the lane is detected when the first distance and the second distance are continuously equal to or less than the distance threshold based on the distance is provided. The first range-finding sensor 11 and the second range-finding sensor 12 are installed so that the radiation direction of the first range-finding sensor 11 and the radiation direction of the second range-finding sensor 12 form a predetermined angle, and vehicle detection is performed. The unit 21 sets the number-of-times threshold value in the irradiation cycle.
With this configuration, the angle 2θ between the radiation direction when the first distance measurement sensor 11 detects the first distance and the radiation direction when the second distance measurement sensor 12 detects the second distance is By installing the vehicle detection device 100 equipped with the first range-finding sensor 11 mounted so as to be less than 180 degrees and the second range-finding sensor 12 on the poles and piles on the side of the roadway. Each of the first range-finding sensor 11 and the second range-finding sensor 12 can detect a vehicle traveling in a range irradiated with the laser beam and a direction in which the vehicle travels.
Furthermore, by updating by setting the number-of-times threshold value in the irradiation cycle, the number-of-times threshold value for an object passing near the sensor and the number-of-times threshold value for an object passing far from the sensor can be made different, so that vehicle detection can be performed. It is possible to reduce the possibility that an object other than the vehicle passes near the device 100 and that the object is erroneously determined as a vehicle, and the possibility that the vehicle cannot be determined as a vehicle when the vehicle passes far away from the vehicle detection device 100.
In the prior art, since the radial directions of the two distance measuring sensors are parallel to each other at the position where each of the two distance measuring sensors is installed, a certain distance is required between the two distance measuring sensors. there were. However, according to the vehicle detection device 100, the first distance measuring sensor 11 is attached so that the angle 2θ formed by the radiation direction of the first distance measuring sensor 11 and the radiation direction of the second distance measuring sensor 12 is less than 180 degrees. The distance between the distance measuring sensor 11 and the second distance measuring sensor 12 can be narrowed.
Further, by attaching the angle 2θ between the radiation direction of the first distance measurement sensor 11 and the radiation direction of the second distance measurement sensor 12 to be less than 180 degrees, the vehicle has a total length of Lh (Lh <Lcmin). When an object other than a vehicle travels in parallel to the roadway, if the vertical distance along the direction perpendicular to the travel route from the distance measuring sensor 10 is farther than Lh / 2 × tan (θ−Φ). Since it is not determined to be a vehicle, false detection can be reduced.
Therefore, in the present embodiment, it is possible to distinguish between a vehicle and other objects passing in front of the vehicle detection device 100, and a passing vehicle even in an environment where a pedestrian or the like passes in front of the vehicle detection device 100. Can be counted accurately.
Further, according to the vehicle detection device 100 of the embodiment, the irradiation cycle is the first distance, which is the distance between the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle 70 passes. The second distance between the first distance measuring sensor 11 detected by irradiating light with the vehicle and the second position which is the second end of the vehicle on the upstream side or the downstream side of the vehicle traveling direction from the first position. The second distance measuring sensor 12 that detects the distance by irradiating light in the irradiation cycle, the time change of the first distance detected by the first distance measuring sensor 11, and the second distance measuring sensor 12 detected. It is provided with a vehicle detection unit 21 that detects the front surface or the rear surface of the vehicle 70 passing through the lane based on either the time variation of the distance. The first range-finding sensor 11 and the second range-finding sensor 12 are installed so that the radiation direction of the first range-finding sensor 11 and the radiation direction of the second range-finding sensor 12 form a predetermined angle.
With this configuration, it is possible to determine whether or not the front or rear surface of the vehicle 70 has been detected. Therefore, in an environment where people, bicycles, etc. frequently pass in front of the vehicle detection device 100, the first distance measuring sensor A state in which both the first distance and the second distance are less than the distance threshold (simultaneous detection) is caused by a plurality of objects other than the vehicle 70 passing in front of the 11 and the second distance measuring sensor 12 at the same time. Even when the number of times threshold TH or more is continuous, it is possible to reduce erroneous determination as a vehicle.

Although the embodiments have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention. These embodiments are included in the scope and gist of the invention, and at the same time, are included in the scope of the invention described in the claims and the equivalent scope thereof.
The vehicle detection device 100 included in the vehicle detection system 1 described above may be realized by a computer. In that case, a program for realizing the function of each functional block is recorded on a computer-readable recording medium. It may be realized by having a computer system read a program recorded on this recording medium and executing it by a CPU. The term "computer system" as used herein includes hardware such as an OS (Operating System) and peripheral devices.
Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM. Further, the "computer-readable recording medium" includes a storage device such as a hard disk built in a computer system.
Further, the "computer-readable recording medium" may include a medium that dynamically holds the program for a short period of time. What dynamically holds the program for a short period of time is, for example, a communication line when the program is transmitted via a network such as the Internet or a communication line such as a telephone line.
Further, the "computer-readable recording medium" may include a medium that holds a program for a certain period of time, such as a volatile memory inside a computer system serving as a server or a client. Further, the above program may be for realizing a part of the above-mentioned functions. Further, the above-mentioned program may be realized by combining the above-mentioned functions with a program already recorded in the computer system. Further, the above program may be realized by using a programmable logic device. The programmable logic device is, for example, an FPGA (Field Programmable Gate Array).

1 ... Vehicle detection system, 10 ... Distance measurement sensor, 11 ... First distance measurement sensor, 12 ... Second distance measurement sensor, 20 ... Information processing unit, 21 ... Vehicle detection unit, 23 ... Storage processing unit, 30 ... Storage unit , 31 ... Program, 32 ... App, 33 ... Vehicle detection information, 40 ... Communication unit, 50 ... Communication network, 60 ... External storage device, 100 ... Vehicle detection device

Claims (12)

A first distance measuring sensor that detects the first distance, which is the distance from the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes by irradiating light in the irradiation cycle. When,
The second distance, which is the distance from the first position to the second position which is the second end of the vehicle on the upstream side or the downstream side in the vehicle traveling direction, is detected by irradiating light in the irradiation cycle. The second distance measuring sensor and
Based on the first distance detected by the first distance measuring sensor and the second distance detected by the second distance measuring sensor, the first distance and the second distance are continuously formed by the number threshold value or more. Is provided with a vehicle detection unit that determines that a vehicle passing through the lane is detected when the distance is equal to or less than the distance threshold value.
The first range-finding sensor and the second range-finding sensor are installed so that the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor form a predetermined angle.
The vehicle detection unit sets the number-of-times threshold value in the irradiation cycle, and sets the threshold value.
For the predetermined angle, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the shortest vehicle length of the vehicle to be detected is set. Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, and the measurement of the first ranging sensor or the second ranging sensor. When the interval time is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
Represented by a vehicle detector. The vehicle detection device according to claim 1, wherein the vehicle detection unit sets the number-of-times threshold value based on the irradiation cycle, the first distance, and the second distance. As for the number of times threshold, the number of times threshold is TH, the irradiation cycle is T, the first distance is d1, the second distance is d2, the predetermined angle is θ, and the first distance measuring sensor is used. The radiation angle is Φ, the radiation angle of the second ranging sensor is Φ, the shortest length of the vehicle to be detected is Lcmin, the maximum speed of the vehicle is Vmax, and max (d1, d2) are d1 and d2. When it is decided to represent the maximum value of
TH = {Lcmin-2 x max (d1, d2) x sin (θ-Φ)} / Vmax x T
The vehicle detection device according to claim 1 or 2, represented by. It is a vehicle detection method executed by the vehicle detection device.
The first distance measuring sensor irradiates light in the irradiation cycle for the first distance, which is the distance between the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes. Steps to detect and
The second distance measuring sensor emits light in the irradiation cycle a second distance, which is the distance between the first position and the second position, which is the second end of the vehicle, on the upstream side or the downstream side in the vehicle traveling direction. And the steps to detect by irradiating
Based on the first distance and the second distance, a vehicle passing through the lane is detected when the first distance and the second distance are equal to or less than the distance threshold in succession of the number of times threshold value or more. The step to determine that it was done and
It has a step of setting the number-of-times threshold value in the irradiation cycle.
The first range-finding sensor and the second range-finding sensor are installed so that the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor form a predetermined angle .
For the predetermined angle, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the shortest vehicle length of the vehicle to be detected is set. Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, and the measurement of the first ranging sensor or the second ranging sensor. When the interval time is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
The vehicle detection method represented by . On the computer of the vehicle detector,
The first distance measuring sensor irradiates light in the irradiation cycle for the first distance, which is the distance between the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes. Steps to detect and
The second distance measuring sensor emits light in the irradiation cycle a second distance, which is the distance between the first position and the second position, which is the second end of the vehicle, on the upstream side or the downstream side in the vehicle traveling direction. And the steps to detect by irradiating
Based on the first distance and the second distance, a vehicle passing through the lane is detected when the first distance and the second distance are equal to or less than the distance threshold in succession of the number of times threshold value or more. The step to determine that it was done and
In the irradiation cycle, the step of setting the number threshold is executed.
The first range-finding sensor and the second range-finding sensor are installed so that the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor form a predetermined angle .
For the predetermined angle, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the shortest vehicle length of the vehicle to be detected is set. Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, and the measurement of the first ranging sensor or the second ranging sensor. When the interval time is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
Represented by a program. A first distance measuring sensor that detects the first distance, which is the distance from the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes by irradiating light in the irradiation cycle. When,
The second distance, which is the distance from the first position to the second position which is the second end of the vehicle on the upstream side or the downstream side in the vehicle traveling direction, is detected by irradiating light in the irradiation cycle. The second distance measuring sensor and
The vehicle passing through the lane based on either the time change of the first distance detected by the first distance measuring sensor and the time change of the second distance detected by the second distance measuring sensor. It is equipped with a vehicle detection unit that detects the front or rear surface of the vehicle.
The first range-finding sensor and the second range-finding sensor are installed so that the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor form a predetermined angle .
For the predetermined angle, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the shortest vehicle length of the vehicle to be detected is set. Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, and the measurement of the first ranging sensor or the second ranging sensor. When the interval time is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
Represented by a vehicle detector. The vehicle detection unit determines that the front surface of the vehicle has been detected when either the time change of the first distance or the time change of the second distance is equal to or less than the first time change threshold value. The vehicle detection device according to claim 6. The vehicle detection unit determines that the rear surface of the vehicle has been detected when either the time change of the first distance or the time change of the second distance is equal to or greater than the second time change threshold value. The vehicle detection device according to claim 6 or 7. The vehicle detection unit is a distance from the time when the first distance measuring sensor or the second distance measuring sensor detects the distance between the front end portion on the right side of the vehicle and the front end portion on the left side of the vehicle. From the time when the time interval to the time when the sensor is detected or the time when the distance to the front end on the left side is detected to the time when the distance from the front end on the right side of the vehicle is detected to the time when the time interval is detected. The vehicle detection device according to any one of claims 6 to 8, which determines whether or not the front surface of the vehicle is detected based on the above. The vehicle detection unit is located between the left rear end portion of the vehicle and the left rear end portion of the vehicle from the time when the first distance measuring sensor or the second distance measuring sensor detects the distance between the first distance measuring sensor and the second rear end portion of the vehicle. At the time interval from the time interval to the time when the distance was detected or the time when the distance to the rear end on the left side was detected to the time when the distance from the rear end on the right side of the vehicle was detected. The vehicle detection device according to any one of claims 6 to 9, which determines whether or not the rear surface of the vehicle is detected based on the time change. It is a vehicle detection method executed by the vehicle detection device.
The first distance measuring sensor irradiates light in the irradiation cycle for the first distance, which is the distance between the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes. Steps to detect and
The second distance measuring sensor emits light in the irradiation cycle a second distance, which is the distance between the first position and the second position, which is the second end of the vehicle, on the upstream side or the downstream side in the vehicle traveling direction. And the steps to detect by irradiating
It has a step of detecting the front or rear surface of the vehicle passing through the lane based on either the time change of the first distance and the time change of the second distance.
The first range-finding sensor and the second range-finding sensor are installed so that the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor form a predetermined angle .
For the predetermined angle, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the shortest vehicle length of the vehicle to be detected is set. Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, and the measurement of the first ranging sensor or the second ranging sensor. When the interval time is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
The vehicle detection method represented by . On the computer of the vehicle detector,
The first distance measuring sensor irradiates light in the irradiation cycle for the first distance, which is the distance between the first position, which is the first end of the vehicle in the vehicle traveling direction, on the lane through which the vehicle passes. Steps to detect and
The second distance measuring sensor emits light in the irradiation cycle a second distance, which is the distance between the first position and the second position, which is the second end of the vehicle, on the upstream side or the downstream side in the vehicle traveling direction. And the steps to detect by irradiating
A step of detecting the front or rear surface of the vehicle passing through the lane based on either the time change of the first distance and the time change of the second distance is executed.
The first range-finding sensor and the second range-finding sensor are installed so that the radiation direction of the first range-finding sensor and the radiation direction of the second range-finding sensor form a predetermined angle .
For the predetermined angle, the predetermined angle is θ, the radiation angle of the first distance measuring sensor is Φ, the radiation angle of the second distance measuring sensor is Φ, and the shortest vehicle length of the vehicle to be detected is set. Lcmin, the maximum speed of the vehicle is Vmax, the maximum value of the vertical distance between the vehicle and the first ranging sensor or the second ranging sensor is Hmax, and the measurement of the first ranging sensor or the second ranging sensor. When the interval time is T,
θ = Φ + Arctan {(Lcmin-Vmax × T) / 2 × Hmax}
Represented by a program.

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