Setting assistance device for radio wave sensor, setting assistance method for radio wave sensor, and computer program

Abstract

This setting assistance device for a radio wave sensor comprises: an acquisition unit that acquires a detection result produced by a radio wave sensor with respect to an object which moves in a target area on a road; a first determination unit that, when a first portion of the target area is included in a detection guarantee area and a second portion of the target area is not included in the detection guarantee area, determines a first definition point for defining the target area in the detection guarantee area on the basis of the acquired detection result in the detection guarantee area; a second determination unit that determines a second definition point which is for defining the first portion in the detection guarantee area and which differs from the first definition point, on the basis of the acquired detection result in the detection guarantee area; and a third determination unit that determines a detection area which corresponds to the first portion on the basis of the determined first definition point and the determined second definition point.

Description

Radio wave sensor setting support device, radio wave sensor setting support method, and computer program

[0001] This disclosure relates to a radio wave sensor configuration support device, a radio wave sensor configuration support method, and a computer program. This application claims priority to Japanese Application No. 2024-123498 filed on July 30, 2024, and incorporates by reference the entire contents of that Japanese application.

[0002] For the purpose of traffic monitoring, radio wave sensors are installed at positions where they can detect objects such as vehicles and pedestrians on roads (including intersections). Such infrastructure (road facility) radio wave sensors are used, for example, to measure the traffic volume of vehicles traveling on roads and detect pedestrians on crosswalks. In order to use a radio wave sensor for traffic monitoring, it is necessary to set areas to be detected (hereinafter referred to as "detection areas"), such as roadways, lanes, crosswalks, and sidewalks, in the coordinate system of the radio wave sensor (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2017-090078

[0004] A radio wave sensor setting assistance device according to one aspect of the present disclosure includes: an acquisition unit that acquires detection results by a radio wave sensor of an object moving in a target area on a road; a first determination unit that, when a detection guaranteed area, an area in which detection of an object by the radio wave sensor can be guaranteed, includes a first portion of the target area but does not include a second portion of the target area, determines a first definition point that defines the target area in the detection guaranteed area based on the detection results in the detection guaranteed area acquired by the acquisition unit; a second determination unit that determines a second definition point, different from the first definition point, that defines the first portion in the detection guaranteed area based on the detection results in the detection guaranteed area acquired by the acquisition unit; and a third determination unit that determines a detection area, an area corresponding to the first portion and in which the radio wave sensor detects objects on the road, based on the first definition point determined by the first determination unit and the second definition point determined by the second determination unit.

[0005] FIG. 1 is a diagram illustrating an example of use of an infrastructure radio wave sensor according to the first embodiment. FIG. 2 is a perspective view illustrating an example of the external configuration of the infrastructure radio wave sensor according to the first embodiment. FIG. 3 is a diagram illustrating an example of setting a detection area in a sensor coordinate system. FIG. 4A is a diagram illustrating a first example of a positional relationship between a detection assurance area and a detection area. FIG. 4B is a diagram illustrating a second example of a positional relationship between a detection assurance area and a detection area. FIG. 5 is a block diagram illustrating an example of a hardware configuration of a setting support device according to the first embodiment. FIG. 6 is a functional block diagram illustrating an example of a function of the setting support device according to the first embodiment. FIG. 7 is a diagram illustrating an example of a walking pattern of a worker at a crosswalk. FIG. 8 is a diagram illustrating an example of a movement trajectory of a worker detected by an infrastructure radio wave sensor when the worker moves according to the movement pattern illustrated in FIG. 7. FIG. 9 is a diagram illustrating an example of an approximation line of a movement trajectory of an object detected by the infrastructure radio wave sensor illustrated in FIG. 8. FIG. 10 is a diagram illustrating an example of determining auxiliary definition points in the example of FIG. 9. FIG. 11 is a diagram illustrating an example of determining a detection area in the example of FIG. 10. FIG. 12 is a flowchart illustrating an example of a setting support operation of an infrastructure radio wave sensor performed by the setting support device according to the first embodiment. FIG. 13 is a diagram showing an example of determining auxiliary definition points according to the third embodiment.

[0006] Depending on the installation location of the radio wave sensor, part of the target area, such as a crosswalk, that the radio wave sensor is to detect objects may fall within an area where the radio wave sensor cannot detect objects. In such cases, it is necessary to appropriately set the detection area to detect objects in the target area.

[0007] According to the present disclosure, when part of a target area falls within an area where an object cannot be detected by a radio wave sensor, a detection area for detecting an object in the target area can be appropriately set.

[0008] The following provides an outline of embodiments of the present disclosure.

[0009] (1) A radio wave sensor configuration assistance device according to this embodiment includes: an acquisition unit that acquires detection results of an object moving in a target area on a road by the radio wave sensor; a first determination unit that, when a detection guaranteed area, an area in which object detection by the radio wave sensor can be guaranteed, includes a first portion of the target area but does not include a second portion of the target area, determines a first definition point in the detection guaranteed area based on the detection results for the detection guaranteed area acquired by the acquisition unit, the first definition point defining the target area in the detection guaranteed area; a second determination unit that, based on the detection results for the detection guaranteed area acquired by the acquisition unit, determines a second definition point, different from the first definition point, in the detection guaranteed area that defines the first portion; and a third determination unit that determines a detection area corresponding to the first portion, the detection area being an area in which the radio wave sensor is to detect objects on the road, based on the first definition point determined by the first determination unit and the second definition point determined by the second determination unit. This makes it possible to appropriately set a detection area for detecting objects in the target area when a part of the target area falls within an area in which the radio wave sensor cannot detect objects.

[0010] (2) In the above (1), the second determination unit may determine the second definition point on an outer edge of the detection assurance area. This makes it possible to determine a more appropriate detection area within the detection assurance area.

[0011] (3) In the above (2), the radio wave sensor configuration assistance device may further include a creation unit that creates an approximation line that approximates a movement trajectory of an object moving along an outer edge of the target area, the movement trajectory being included in the detection result acquired by the acquisition unit, and the second determination unit may determine the second definition point at an intersection of the approximation line created by the creation unit and the outer edge of the detection guaranteed area. This makes it possible to determine the second definition point at an appropriate position.

[0012] (4) In the above (2), the second determination unit may determine the second definition point at a starting point of a movement trajectory of an object moving along an outer edge of the target area from outside the detection assurance area to inside the detection assurance area, the movement trajectory being included in the detection result acquired by the acquisition unit. This makes it possible to determine the second definition point at an appropriate position.

[0013] (5) In the above (2), the second determination unit may determine the second definition point at an end point of a movement trajectory of an object moving along an outer edge of the target area from inside the detection assurance area to outside the detection assurance area, the movement trajectory being included in the detection result acquired by the acquisition unit. This makes it possible to determine the second definition point at an appropriate position.

[0014] (6) In any one of (1) to (5) above, the target area may be a crosswalk, and the detection area may include a zebra area corresponding to the crosswalk and a waiting area for pedestrians adjacent to the crosswalk. This makes it possible to appropriately determine the detection area including the zebra area and the waiting area.

[0015] (7) In the above (6), the third determination unit may determine an area surrounded by the first definition point and the second definition point as the zebra area. This makes it possible to appropriately determine the zebra area within the detection guaranteed area.

[0016] (8) In the above (7), the third determination unit may determine the waiting area adjacent to an end of the zebra area in the longitudinal direction. This makes it possible to determine the waiting area at an appropriate position relative to the zebra area.

[0017] (9) In the above (8), the third determination unit may determine the waiting area adjacent to a first longitudinal end of the zebra area that does not include the second definition point, and may not determine the waiting area adjacent to a second longitudinal end of the zebra area that includes the second definition point. This makes it possible to avoid determining a waiting area outside the detection guaranteed area.

[0018] (10) In the above (8), the third determination unit may determine the waiting area adjacent to a longitudinal end of the zebra area including the second definition point within the detection guaranteed area, thereby making it possible to appropriately determine the waiting area within the detection guaranteed area.

[0019] (11) A radio wave sensor configuration support method according to the present embodiment includes the steps of: acquiring detection results of an object moving in a target area on a road by a radio wave sensor; when a detection guaranteed area, which is an area in which object detection by the radio wave sensor can be guaranteed, includes a first portion of the target area but does not include a second portion of the target area, determining a first definition point in the detection guaranteed area based on the detection results in the acquired detection guaranteed area that defines the target area; determining a second definition point in the detection guaranteed area that is different from the first definition point and that defines the first portion based on the detection results in the detection guaranteed area; and determining a detection area that corresponds to the first portion and is an area in which the radio wave sensor detects objects on the road based on the determined first definition point and the determined second definition point. This makes it possible to appropriately set a detection area for detecting objects in the target area even when part of the target area falls within an area in which the radio wave sensor cannot detect objects.

[0020] (12) A computer program according to this embodiment is a computer program for assisting in setting a radio wave sensor that detects an object in a target area on a road, the computer program causing a computer to execute the following steps: acquiring detection results of an object moving in the target area by the radio wave sensor; when a detection guaranteed area, an area in which object detection by the radio wave sensor can be guaranteed, includes a first portion of the target area but does not include a second portion of the target area, determining a first definition point in the detection guaranteed area based on the detection results in the acquired detection guaranteed area that defines the target area; determining a second definition point in the detection guaranteed area that is different from the first definition point and defines the first portion based on the detection results in the detection guaranteed area; and determining a detection area that corresponds to the first portion and is an area in which the radio wave sensor detects objects on the road based on the determined first definition point and the determined second definition point. This makes it possible to appropriately set a detection area for detecting objects in the target area even when part of the target area falls within an area in which the radio wave sensor cannot detect objects.

[0021] The present disclosure can be realized not only as a radio wave sensor setting support device having the above-described characteristic configuration, a radio wave sensor setting support method having characteristic processing steps, and a computer program for causing the setting support device to execute the characteristic processing, but also as a system in which part or all of the radio wave sensor setting support device is realized as a semiconductor integrated circuit, or a system that includes the radio wave sensor setting support device as part of it.

[0022] Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0023] [1. First Embodiment] [1-1. Infrastructure Radio Wave Sensor] Fig. 1 is a diagram showing an example of use of an infrastructure radio wave sensor according to a first embodiment. The infrastructure radio wave sensor 10 according to the first embodiment is a radio wave radar for traffic monitoring, and detects objects in a target area on a road. Here, a crosswalk 20 is used as an example of the target area, and a pedestrian is used as an example of the object. That is, the infrastructure radio wave sensor 10 detects pedestrians at the crosswalk 20. The infrastructure radio wave sensor 10 is, for example, a millimeter-wave radar.

[0024] The crosswalk 20 is provided on a roadway 60 near an intersection 61. Sidewalks 63a and 63b are provided adjacent to the roadway 60. The roadway 60 includes an oncoming lane 62a through which vehicles enter the intersection 61 and an outgoing lane 62b through which vehicles exit the intersection 61. The sidewalk 63a is adjacent to the oncoming lane 62a. The sidewalk 63b is adjacent to the outgoing lane 62b.

[0025] The infrastructure radio wave sensor 10 is attached to a structure 50 provided on a sidewalk 63a. The structure 50 is several meters tall, and the infrastructure radio wave sensor 10 is installed several meters above the ground. The structure 50 includes, for example, a pole 51 and an arm 52 provided near the top end of the pole 51, and the infrastructure radio wave sensor 10 is attached to the arm 52.

[0026] FIG. 2 is a perspective view showing an example of the external configuration of the infrastructure radio wave sensor 10 according to the first embodiment. As shown in FIG. 2, the infrastructure radio wave sensor 10 includes a housing 18 having a transmitting / receiving surface 18a on one surface for transmitting and receiving radio waves. The housing 18 houses a transmitting / receiving unit 14 and a detection circuit 17. The transmitting / receiving unit 14 includes a transmitting antenna 15a and multiple (e.g., four) receiving antennas 16a. The infrastructure radio wave sensor 10 transmits modulated waves, which are radio waves, from the transmitting antenna 15a through the transmitting / receiving surface 18a. The modulated waves hit an object and are reflected, and the receiving antenna 16a receives the reflected waves. The transmitting / receiving unit 14 and the detection circuit 17 perform signal processing on the transmitted wave signal and the received wave signal to detect the distance to the object, the line-of-sight velocity of the object, and the azimuth angle at which the object is located.

[0027] The infrastructure radio wave sensor 10 detects objects (e.g., pedestrians, bicycles) on the crosswalk 20 by emitting radio waves (millimeter waves) onto the crosswalk 20 and receiving the reflected waves. Specifically, the infrastructure radio wave sensor 10 is positioned so that a line (hereinafter also referred to as the "projection center axis") obtained by projecting a normal line of the transmission / reception surface 18a that transmits and receives radio waves in the vertical direction onto the ground surface passes through the crosswalk 20. The infrastructure radio wave sensor 10 can detect the distance from the infrastructure radio wave sensor 10 to the object, the speed of the object (the speed in the linear direction connecting the infrastructure radio wave sensor 10 and the object; hereinafter also referred to as the "line-of-sight speed"), and the horizontal angle (azimuth angle) of the position of the object relative to the projection center axis.

[0028] [1-2. Detection Area] A detection area 30, which is a range on a road for detecting an object, is set in the infrastructure radio wave sensor 10. In Fig. 1, the detection area 30 is shown as if it exists in real space, but the detection area 30 is information set inside the infrastructure radio wave sensor 10 and is a virtual area.

[0029] For example, the infrastructure radio wave sensor 10 used to measure the number of pedestrians and bicycles (including riders; hereinafter, pedestrians and bicycles will be simply referred to as "pedestrians") crossing the crosswalk 20 or to control traffic signals installed at the crosswalk 20 is required to detect not only pedestrians on the crosswalk but also pedestrians waiting to cross on the sidewalk adjacent to the crosswalk 20. For this reason, for example, the detection area 30 includes not only the area of ​​the crosswalk 20 but also an area on the sidewalk where pedestrians wait to cross. In other words, the detection area 30 may be an area extending from the crosswalk 20 on both sides in the longitudinal direction of the crosswalk 20 (the direction in which pedestrians walk on the crosswalk).

[0030] A coordinate space is set in the infrastructure radio wave sensor 10 to identify the position of an object. Hereinafter, the coordinate space set in the infrastructure radio wave sensor 10 is also referred to as the “sensor coordinate space.” The sensor coordinate space is a coordinate space unique to the infrastructure radio wave sensor 10.

[0031] In the infrastructure radio wave sensor 10, a detection area 30 is set in the sensor coordinate space in order to detect an object on the crosswalk 20.

[0032] FIG. 3 is a diagram for explaining an example of setting a detection area in a sensor coordinate system.

[0033] 3, the point indicated by the reference symbol 31O is a point on the ground surface that is a vertically downward projection of the installation position of the infrastructure radio wave sensor 10. The line indicated by the reference symbol 31Y is the projection center axis, and the line indicated by the reference symbol 31X is a line on the ground surface that intersects with the projection center axis 31Y at the point 31O.

[0034] For example, the sensor coordinate space is a virtual coordinate space set in the infrastructure radio wave sensor 10, and is a two-dimensional coordinate space corresponding to the earth's surface. The sensor coordinate space is defined by an X axis and a Y axis. The origin O of the sensor coordinate space corresponds to the real point 31O. The Y axis of the sensor coordinate space corresponds to the real projection center axis 31Y. The X axis of the sensor coordinate space corresponds to the real line 31X.

[0035] In the infrastructure radio wave sensor 10, a virtual detection area 300 corresponding to a detection area 30 in real space is set in the sensor coordinate space. The detection area 30 is, for example, an area that includes a crosswalk 20. Note that hereinafter, the detection area set as internal information in the infrastructure radio wave sensor 10 is indicated by the reference numeral 300, and the detection area in real space that reflects the detection area 300 is indicated by the reference numeral 30.

[0036] For example, the detection area 30 is divided into a zebra area 30_1, which is the area of ​​the crosswalk 20, and waiting areas 30_2 and 30_3, which are provided on both ends of the zebra area 30_1. The waiting areas 30_2 and 30_3 are areas that extend from the zebra area 30_1 in the longitudinal direction (the direction of the projection center axis 31Y), and are areas where pedestrians wait on the sidewalk while waiting for the traffic light to change.

[0037] The detection area 300 in the sensor coordinate space is divided into a zebra area 300_1 and waiting areas 300_2 and 300_3. The zebra area 300_1 corresponds to the zebra area 30_1 in the real space. The waiting area 300_2 corresponds to the waiting area 30_2 in the real space, and the waiting area 300_3 corresponds to the waiting area 30_3 in the real space.

[0038] The infrastructure radio wave sensor 10 has a detection guaranteed area 40 (see FIG. 1 ). The detection guaranteed area 40 is an area where object detection by the infrastructure radio wave sensor 10 is guaranteed. The detection guaranteed area 40 is an area where radio waves are transmitted from the infrastructure radio wave sensor 10 and where the infrastructure radio wave sensor 10 can receive reflected waves from the object. In other words, the infrastructure radio wave sensor 10 can detect an object present in the detection guaranteed area 40 and obtain detection results for the object. The strength of the radio waves radiated from the transmitting / receiving surface 18a is higher, for example, closer to the normal (central axis) of the transmitting / receiving surface 18a and lower, for example, the further away from the central axis. Therefore, the farther the position of the object to be detected (e.g., a pedestrian) is from the central axis of the transmitting / receiving surface 18a, the lower the strength of the reflected waves from the object. If the reception level of the reflected waves from the object becomes too low, the infrastructure radio wave sensor 10 cannot detect the object. For this reason, the detection guaranteed area 40 is formed, for example, in a fan shape centered on the projection central axis. For example, the detection guaranteed area 40 is the range in which an object reflects the radio waves emitted by the infrastructure radio wave sensor 10 and the infrastructure radio wave sensor 10 can detect the object by the reflected waves from the object, and does not include the range in which the infrastructure radio wave sensor 10 cannot detect an object even if it can emit radio waves.

[0039] For example, the detection area 30 is set as part of the detection guaranteed area 40 of the infrastructure radio wave sensor 10. In other words, the detection guaranteed area 40 covers the detection area 30. The detection area 30 is an area that includes at least a part of the crosswalk 20, for example.

[0040] 4A is a diagram showing a first example of the positional relationship between the detection guaranteed area and the detection area. In Fig. 4A, the entire crosswalk 20A is included in the detection guaranteed area 40. In the example of Fig. 4A, an object (pedestrian) on the crosswalk 20 can be detected by the infrastructure radio wave sensor 10.

[0041] In the example of FIG. 4A , the detection guaranteed area 40 covers the entire crosswalk 20A. More specifically, the detection guaranteed area 40 covers an area including the entire crosswalk 20A and portions of sidewalks 63a and 63b adjacent to the crosswalk 20A. When the detection guaranteed area 40 includes the crosswalk 20A as in FIG. 4A , a detection area 30A including the entire crosswalk 20A can be set. More specifically, in the example of FIG. 4A , the detection area 30A includes a zebra area 30A_1 corresponding to the crosswalk 20A and waiting areas 30A_2 and 30A_3 corresponding to the adjacent portions of the crosswalk 20A. The zebra area 30A_1 and the waiting areas 30A_2 and 30A_3 are included in the detection guaranteed area 40.

[0042] 4B is a diagram showing a second example of the positional relationship between the detection guaranteed area and the detection area. In Fig. 4B, the entire crosswalk 20A is not included in the detection guaranteed area 40, and part of the crosswalk 20A is outside the detection guaranteed area 40. In the example of Fig. 4B, an object (pedestrian) in part of the crosswalk 20A cannot be detected by the infrastructure radio wave sensor 10.

[0043] 4B , if the detection-guaranteed area 40 does not include part of the crosswalk 20A, setting a detection area that includes the entire crosswalk 20A may result in inaccurate detection of pedestrians on the crosswalk 20A. In the present disclosure, if the detection-guaranteed area 40 does not include part of the crosswalk 20A, a detection area 30B is set within the detection-guaranteed area 40. In other words, the detection area 30B does not include the entire crosswalk 20A. The detection area 30B includes a first portion of the crosswalk 20A that is included in the detection-guaranteed area 40, and does not include a second portion of the crosswalk 20A that is not included in the detection-guaranteed area 40.

[0044] For example, depending on the orientation of the infrastructure radio wave sensor 10, a blind spot may be created directly below the infrastructure radio wave sensor 10. For example, areas on the left and right of the projection center axis that are close to the infrastructure radio wave sensor 10 are not included in the detection guaranteed area 40. In the example of FIG. 4B , the infrastructure radio wave sensor 10 is too close to the crosswalk 20A, so a part of the side of the crosswalk 20A that is close to the infrastructure radio wave sensor 10 (the left edge portion) is outside the detection guaranteed area 40.

[0045] 4B , detection area 30B is missing a left end portion 31B on the side of crosswalk 20A that is close to infrastructure radio wave sensor 10. In other words, detection area 30B includes a zebra area 30B_1 in which left end portion 31B on the side of crosswalk 20A that is close to infrastructure radio wave sensor 10 is missing.

[0046] 4B , the portion of the sidewalk 63b away from the infrastructure radio wave sensor 10 adjacent to the crosswalk 20A is included in the detection guaranteed area 40. Therefore, in the example of FIG. 4B , similar to the example of FIG. 4A , the detection area 30B includes a waiting area 30B_3 that corresponds to the portion of the sidewalk 63b away from the infrastructure radio wave sensor 10 adjacent to the crosswalk 20A.

[0047] 4B , the detection guaranteed area 40 is not large enough to set a waiting area on the sidewalk 63a close to the infrastructure radio wave sensor 10. As described above, a portion of the crosswalk 20A on the side close to the infrastructure radio wave sensor 10 is not included in the detection guaranteed area 40. On the sidewalk 63a, an adjacent portion of the crosswalk 20A that is not included in the detection guaranteed area 40 is outside the detection guaranteed area 40. In the first embodiment, a waiting area 30B_2 is set that excludes the portion outside the detection guaranteed area 40. In other words, the detection area 30B includes a waiting area 30B_2 with its left edge portion missing on the sidewalk 63a close to the infrastructure radio wave sensor 10.

[0048] [1-3. Configuration of the Setting Support Device] Fig. 5 is a block diagram showing an example of the hardware configuration of the setting support device according to the first embodiment. The setting support device 100 according to the first embodiment is used by a user who sets the detection area 30 of the infrastructure radio wave sensor 10. The setting support device 100 includes a processor 101, a non-volatile memory 102, a volatile memory 103, an input / output interface 104, a graphics controller 105, and a communication interface 106. The setting support device 100 further includes an input device 201 and a display device 202. Note that at least one of the input device 201 and the display device 202 may be an external device connected to the setting support device 100.

[0049] The volatile memory 103 is a semiconductor memory such as an SRAM (Static Random Access Memory) or a DRAM (Dynamic Random Access Memory). The non-volatile memory 102 is a flash memory, a hard disk, a ROM (Read Only Memory), or the like. The non-volatile memory 102 stores a setting assistance program 107, which is a computer program, and data used to execute the setting assistance program 107. Each function of the setting assistance device 100 is realized when the setting assistance program 107 is executed by the processor 101. The setting assistance program 107 can be stored in a recording medium such as a flash memory, a ROM, or a CD-ROM. The processor 101 uses the setting assistance program 107 to assist the user in setting the detection area of ​​the infrastructure radio wave sensor 10.

[0050] The processor 101 is, for example, a CPU (Central Processing Unit). However, the processor 101 is not limited to a CPU. The processor 101 may also be a GPU (Graphics Processing Unit). The processor 101 may also be, for example, an ASIC (Application Specific Integrated Circuit) or a programmable logic device such as an FPGA (Field Programmable Gate Array). In this case, the ASIC or programmable logic device is configured to be able to execute processing similar to that of the setting assistance program 107.

[0051] For example, the input device 201 includes a keyboard and a pointing device such as a mouse. The input device 201 may be a capacitive or pressure-sensitive touchpad overlaid on the screen of the display device 202. The input device 201 is used to input data to the setting assistance device 100. The input / output interface 104 is connected to the input device 201. The input / output interface 104 accepts input data from the input device 201 and provides the accepted data to the processor 101.

[0052] The display device 202 includes, for example, a liquid crystal panel or an OEL (organic electroluminescence) panel. The display device 202 can display text or graphic information. The graphics controller 105 is connected to the display device 202 and controls the display on the display device 202. The graphics controller 105 includes, for example, a GPU and a VRAM (Video RAM), stores data to be displayed on the display device 202 in the VRAM, periodically reads one frame of video data from the VRAM, and generates a video signal. The generated video signal is output to the display device 202, and the video is displayed on the display device 202. The function of the graphics controller 105 may be included in the processor 101. A portion of the area of ​​the volatile memory 103 may be used as the VRAM.

[0053] The communication interface 106 can communicate with an external device. For example, the communication interface 106 is connected to the infrastructure radio wave sensor 10 by a communication cable and can communicate with the infrastructure radio wave sensor 10. The communication interface 106 may be a wireless communication interface and can communicate with the infrastructure radio wave sensor 10 wirelessly.

[0054] For example, the nonvolatile memory 102 stores detection guarantee area information 108, which is position information of a detection guarantee area 400 (see FIG. 8 , etc., described later) of the infrastructure radio wave sensor 10 in the sensor coordinate space. For example, the detection guarantee area information 108 is information indicating the outer edge of the detection guarantee area 400.

[0055] [1-4. Functions of the Setting Support Device] When a part of a crosswalk 20A falls outside the detection guaranteed area 40, as in the example shown in FIG. 4B , the setting support device 100 according to the first embodiment supports setting, in the infrastructure radio wave sensor 10, a detection area 30B included in the detection guaranteed area 40.

[0056] 6 is a functional block diagram showing an example of the functions of the setting assistance device according to the first embodiment. When the processor 101 executes the setting assistance program 107, the setting assistance device 100 functions as an acquisition unit 111, a creation unit 112, a first determination unit 113, a second determination unit 114, a third determination unit 115, and a setting unit 116.

[0057] The infrastructure radio wave sensor 10 can be set to two operation modes: a setting mode and an operation mode. The setting mode is an operation mode for setting a detection area in the infrastructure radio wave sensor 10. The operation mode is an operation mode for detecting objects for traffic monitoring after the detection area has been set.

[0058] When setting a detection area, the infrastructure radio wave sensor 10 is started in a setting mode. The setting assistance device 100 communicates with the infrastructure radio wave sensor 10 operating in the setting mode and sets the detection area.

[0059] In the setting mode, the infrastructure radio wave sensor 10 detects an object to set a detection area. Referring to Fig. 2, the infrastructure radio wave sensor 10 emits radio waves from the transmitting antenna 15a and receives reflected waves of the radio waves from the receiving antenna 16a. The infrastructure radio wave sensor 10 detects the position of the object based on the reflected waves received by the receiving antenna 16a.

[0060] Specifically, the transmitting antenna 15a transmits a modulated wave signal. The transmitting signal from the transmitting antenna 15a hits an object and is reflected. The receiving antenna 16a receives the reflected wave from the object. The detection circuit 17 combines the transmitted modulated wave signal with the received reflected wave signal to generate an intermediate frequency signal (hereinafter referred to as an "IF signal"). The detection circuit 17 performs a fast Fourier transform (FFT) on the IF signal to obtain information on distance, speed, and azimuth angle.

[0061] The detection circuit 17 identifies the position (coordinate value) of the peak point of the reflected wave (the maximum point of the signal level of the reflected wave; hereinafter, also referred to as the "reflection point") in the sensor coordinate space based on, for example, the acquired distance and azimuth angle information. The detection circuit 17 outputs the detection result including the coordinate value of the reflection point.

[0062] In a specific example, the infrastructure radio wave sensor 10 in the setting mode detects an object on a road during a certain detection period. For example, the detection period is a period of one second or more and one hour or less. The infrastructure radio wave sensor 10 continuously detects the positions of reflection points during the detection period. The detection result output from the infrastructure radio wave sensor 10 includes coordinate values ​​of all reflection points detected during the detection period. Returning to FIG. 6 , the acquisition unit 111 acquires the detection result of the infrastructure radio wave sensor 10 detecting an object during the detection period. The acquisition unit 111 acquires the detection result of an object moving on a crosswalk from the infrastructure radio wave sensor 10 set to the setting mode. That is, the acquisition unit 111 acquires the detection result by receiving the detection result from the infrastructure radio wave sensor 10.

[0063] The infrastructure radio wave sensor 10 has a tracking function for tracking detected objects. The tracking function is a function for tracking moving objects. Specifically, the infrastructure radio wave sensor 10 assigns an ID to each detected object. The detection circuit 17 detects the position and speed of the object at regular time intervals. The infrastructure radio wave sensor 10 identifies currently detected objects that are the same as the previously detected object. For example, the infrastructure radio wave sensor 10 estimates the current position of object a based on the previous movement direction and speed of object a. Among the currently detected objects, the infrastructure radio wave sensor 10 identifies the object closest to the position estimated from the previous movement direction and speed of object a as object a. An object identified as the same as the previously detected object retains the ID of the previously detected object. For example, the infrastructure radio wave sensor 10 outputs detection data that associates the object ID with the object's position and speed. In another example, the infrastructure radio wave sensor 10 may collectively output multiple positions and speeds of the same object detected during a detection period.

[0064] For example, the acquisition unit 111 acquires movement trajectories of one or more objects moving on a road including the crosswalk 20A, detected by the infrastructure radio wave sensor 10. For example, the acquisition unit 111 receives detection data output from the infrastructure radio wave sensor 10 and stores the detection data for a detection period. The acquisition unit 111 generates a movement trajectory for each object from the stored detection data for the detection period. That is, the acquisition unit 111 connects the positions of objects assigned the same ID in chronological order to generate the movement trajectory of the object. In another example, the acquisition unit 111 can acquire the movement trajectory of the object by receiving movement trajectory data output from the infrastructure radio wave sensor 10.

[0065] The infrastructure radio wave sensor 10 outputs a detection result at predetermined time intervals. When an object such as a pedestrian, bicycle, or vehicle moves, the position of the object detected by the infrastructure radio wave sensor 10 changes. The detection result includes position information of the object and time information of the object detection. The position of the object output from the infrastructure radio wave sensor 10 is displayed, for example, on the display device 202. For example, the display device 202 depicts the position of the detected object as a point in the sensor coordinate space. For example, a movement trajectory is formed by a set of points indicating the position of the same object at each time. In another example, the display device 202 may display the movement trajectory as a line by connecting points arranged in chronological order with a line.

[0066] For example, a worker walks in a specific pattern on the crosswalk 20A. FIG. 7 is a diagram showing an example of a walking pattern of a worker on the crosswalk. In one specific example, the worker walks along the outer edge of the crosswalk 20A and stops for a certain period of time (several seconds) at the endpoints (four corners) of the crosswalk. That is, the worker walks along a route R1 along the right edge of the crosswalk 20A from the right endpoint P1 on the side of the crosswalk 20A that is close to the infrastructure radio wave sensor 10 to the right endpoint P2 on the side of the crosswalk 20A that is farther from the infrastructure radio wave sensor 10. When the worker reaches endpoint P2, he stops at endpoint P2 for several seconds. The worker then walks along a route R2 along the edge of the crosswalk 20A that is farther from the infrastructure radio wave sensor 10 from the right endpoint P2 on the side of the crosswalk 20A that is farther from the infrastructure radio wave sensor 10 to the left endpoint P3. When the worker reaches endpoint P3, he stops at endpoint P3 for several seconds. The worker then walks along path R3 along the left edge of crosswalk 20A, from left endpoint P3 on the side of crosswalk 20A that is farther from infrastructure radio wave sensor 10 to left endpoint P4 on the side of crosswalk 20A that is closer to infrastructure radio wave sensor 10. When the worker reaches left endpoint P4, he or she remains stationary at left endpoint P4 for several seconds. The worker then walks along path R4 from left endpoint P4 on the side of crosswalk 20A that is closer to infrastructure radio wave sensor 10 to right endpoint P1, along the edge of crosswalk 20A that is closer to infrastructure radio wave sensor 10.

[0067] Fig. 8 is a diagram showing an example of a movement trajectory of a worker detected by an infrastructure radio wave sensor when the worker moves according to the movement pattern shown in Fig. 7. For example, as shown in Fig. 8, the detection result of the worker's movement trajectory by the infrastructure radio wave sensor 10 may be displayed on the display device 202. Furthermore, as shown in Fig. 8, the setting assistance device 100 may use the detection guarantee area information 108 to display a detection guarantee area 400 superimposed on the worker's movement trajectory. This allows the user to understand the positional relationship between the detection guarantee area 400 and the worker's movement trajectory.

[0068] 8 , trajectories R1m, R2m, R3m, and R4m are detection results of the movement trajectories of the worker along routes R1, R2, R3, and R4 detected by the infrastructure radio wave sensor 10. That is, the detection results of the infrastructure radio wave sensor 10 detecting the positions of the worker who moved along route R1 are detection trajectory R1m, the detection results of the infrastructure radio wave sensor 10 detecting the positions of the worker who moved along route R2 are detection trajectory R2m, the detection results of the infrastructure radio wave sensor 10 detecting the positions of the worker who moved along route R3 are detection trajectory R3m, and the detection results of the infrastructure radio wave sensor 10 detecting the positions of the worker who moved along route R4 are detection trajectory R4m.

[0069] Detection points P1m, P2m, and P3m are the detection results of the endpoints P1, P2, and P3 by the infrastructure radio wave sensor 10. That is, the result of the infrastructure radio wave sensor 10 detecting a stationary worker at endpoint P1 is detection point P1m, the result of the infrastructure radio wave sensor 10 detecting a stationary worker at endpoint P2 is detection point P2m, and the result of the infrastructure radio wave sensor 10 detecting a stationary worker at endpoint P3 is detection point P3m.

[0070] The detection results by the infrastructure radio wave sensor 10 may contain errors. Therefore, even if the worker moves in a straight line, the movement trajectory detected by the infrastructure radio wave sensor 10 will zigzag. Therefore, to make it easier to distinguish the movement trajectory of the worker from the movement trajectories of other objects (e.g., pedestrians or vehicles), the worker moves according to a distinctive movement pattern.

[0071] For example, the movement trajectory of the worker may be identified by a function of the setting support device 100. Specifically, the setting support device 100 stores information on a specific movement pattern in advance. The setting support device 100 compares the movement trajectory acquired by the acquisition unit 111 with the specific movement pattern, and if the movement trajectory matches the specific movement pattern, identifies the movement trajectory as the movement trajectory of the worker.

[0072] As another example, the display device 202 may display the movement trajectories acquired by the acquisition unit 111, and the user may recognize a movement trajectory having the same or similar shape as the worker's movement pattern as the worker's movement trajectory and specify the movement trajectory by clicking on the movement trajectory. The setting support device 100 may determine the specified movement trajectory as the worker's movement trajectory.

[0073] For example, as described above, the movement pattern of the worker includes stopping at the endpoints P1, P2, P3, and P4 of the outer edge of the crosswalk. The setting support device 100 may be able to distinguish between the detection trajectories R1m, R2m, R3m, and R4m and the detection points P1m, P2m, and P3m where the worker stops. As another example, the user may specify the detection points P1m, P2m, and P3m displayed on the display device 202 by clicking them. The setting support device 100 can determine the specified detection points P1m, P2m, and P3m as the worker's stop points.

[0074] Referring to FIG. 7 , the left end portion of the crosswalk 20 on the proximity side of the infrastructure radio wave sensor 10 is outside the detection guaranteed area 40. That is, part of route R3, part of route R4, and endpoint P4 are not included in the detection guaranteed area 40. Returning to FIG. 8 , the worker is not detected in areas outside the detection guaranteed area 40. That is, detection trajectory R3m is the result of detection by the infrastructure radio wave sensor 10 of the part of route R3 along which the worker traveled that is included in the detection guaranteed area 40. Detection trajectory R4m is the result of detection by the infrastructure radio wave sensor 10 of the part of route R4 along which the worker traveled that is included in the detection guaranteed area 40. The part of route R3 along which the worker traveled that is not included in the detection guaranteed area 40, the part of route R4 along which the worker traveled that is not included in the detection guaranteed area 40, and endpoint P4 where the worker stopped are not included in the detection results of the infrastructure radio wave sensor 10. That is, the detected trajectory R3m in Figure 8 is the detection result of the trajectory up to halfway along the trajectory of the worker moving from endpoint P3 to endpoint P4 along route R3, and the detected trajectory R4m is the detection result of the trajectory from halfway along the trajectory of the worker moving from endpoint P4 to endpoint P1 along route R4.

[0075] 6 , the creation unit 112 creates an approximation line that approximates the movement trajectory of an object moving along the outer edge of the crosswalk 20, which is included in the detection result acquired by the acquisition unit 111. As described above, an example of a specific movement pattern is a pattern of movement along the outer edge of the crosswalk 20. In the example of FIG. 8 , the creation unit 112 creates an approximation line that approximates the detection trajectories R1m, R2m, R3m, and R4m from the detection results acquired by the acquisition unit 111.

[0076] 9 is a diagram showing an example of approximation lines of the movement trajectories of objects detected by the infrastructure radio wave sensor shown in FIG. 8. For example, the creation unit 112 creates approximation lines of the detection trajectory R3m of an object moving from inside the detection guaranteed area 400 to outside the detection guaranteed area 400 and the detection trajectory R4m of an object moving from outside the detection guaranteed area 400 to inside the detection guaranteed area 400, among the detection trajectories R1m, R2m, R3m, and R4m along the outer edge of the crosswalk 20. The detection trajectory R3m of an object moving from inside the detection guaranteed area 400 to outside the detection guaranteed area 400 and the detection trajectory R4m of an object moving from outside the detection guaranteed area 400 to inside the detection guaranteed area 400 have ends (starting ends or ending ends) near the outer edge of the detection guaranteed area 400. That is, the creation unit 112 determines whether each of the detection trajectories R1m, R2m, R3m, and R4m is a detection trajectory that has an end (starting end or ending end) near the outer edge of the detection guarantee area 400, and can create approximate lines of the detection trajectories R3m and R4m that have an end (starting end or ending end) near the outer edge of the detection guarantee area 400.

[0077] Returning to FIG. 6 , the first determination unit 113 determines definition points that define the crosswalk 20 in the detection guaranteed area 400 based on the detection results acquired by the acquisition unit 111. See FIG. 9 . For example, the definition points are endpoints of the crosswalk 20. For example, if the crosswalk 20 is a polygon, the definition points are vertices of the polygon. If the crosswalk 20 is a figure in which some sides of the polygon are curved (e.g., the crosswalk 20A shown in FIG. 7 ), the definition points are intersections (vertices) of two lines that make up the figure, intersections of a line and a curve that make up the figure, and intersections of two curves that make up the figure. For example, the definition points may include a point midway on one side of the polygon that is the crosswalk 20, or may include a point midway on a curve that makes up the figure of the crosswalk 20. The definition points are an example of a "first definition point."

[0078] For example, if a specific movement pattern includes stopping at an end point of the crosswalk 20, the first determination unit 113 can determine, as a definition point, the position (e.g., the average value of multiple detection positions) of an object detected at the same or nearby position for a certain period (e.g., a period during which the object is stopping). In the example of Fig. 9, the detection point P1m shown in Fig. 8 is determined as the definition point DP1, the detection point P2m is determined as the definition point DP2, and the detection point P3m is determined as the definition point DP3.

[0079] Returning to Fig. 6, the second determination unit 114 determines an auxiliary definition point in the detection guaranteed area 400 based on the detection result acquired by the acquisition unit 111. The auxiliary definition point is a point that defines the first portion of the crosswalk 20 when the detection guaranteed area 40 includes a first portion of the crosswalk 20 but does not include a second portion of the crosswalk 20, and is a point that is different from the definition point. The auxiliary definition point is an example of a "second definition point."

[0080] The auxiliary definition points will be described in more detail with reference to Figure 7. In the example of Figure 7, the definition points are endpoints P1, P2, P3, and P4 of the crosswalk 20A. A midpoint P5 of the left edge of the crosswalk 20A (the line segment connecting endpoints P3 and P4) is the intersection of the left edge of the crosswalk 20A and the outer edge of the detection guaranteed area 40. A midpoint P6 of the edge of the crosswalk 20A close to the infrastructure radio wave sensor 10 (the curve connecting endpoints P4 and P1; hereinafter, also referred to as the "near edge") is the intersection of the near edge of the crosswalk 20A and the outer edge of the detection guaranteed area 40.

[0081] The intermediate points P5 and P6 are located on the outer edge of the detection guaranteed area 40, that is, on the boundary between the inside and outside of the detection guaranteed area 40.

[0082] The first portion of the crosswalk 20A included in the detection-guaranteed area 40 is the area bounded by the endpoints P1, P2, and P3 and the intermediate points P5 and P6. The second portion of the crosswalk 20A not included in the detection-guaranteed area 40 is the area bounded by the endpoint P4 and the intermediate points P5 and P6. That is, the first portion is defined by the endpoints P1, P2, and P3 and the intermediate points P5 and P6, and the second portion is defined by the endpoint P4 and the intermediate points P5 and P6. The intermediate points P5 and P6 are points that define the first portion and are different from the endpoints P1, P2, P3, and P4 that define the crosswalk 20A. That is, the intermediate points P5 and P6 are auxiliary definition points.

[0083] 6 , for example, the second determination unit 114 determines an auxiliary definition point on the outer edge of the detection assurance area 400. In a more specific example, the second determination unit 114 can determine an auxiliary definition point at the intersection of the approximation line created by the creation unit 112 and the outer edge of the detection assurance area 400.

[0084] Fig. 10 is a diagram showing an example of determining auxiliary definition points in the example of Fig. 9. In Fig. 10, the intersection of the approximation line AL3 and the outer edge of the detection assurance area 400 is determined as auxiliary definition point SDP4. The intersection of the approximation line AL4 and the outer edge of the detection assurance area 400 is determined as auxiliary definition point SDP5.

[0085] Returning to Figure 6, the third determination unit 115 determines the detection area corresponding to the first part based on the definition points DP1, DP2, and DP3 determined by the first determination unit 113 and the auxiliary definition points SDP4 and SDP5 determined by the second determination unit 114.

[0086] FIG. 11 is a diagram showing an example of determining a detection area in the example of FIG. 10 . As shown in FIG. 11 , for example, detection area 300B includes zebra area 300B_1 corresponding to crosswalk 20A and pedestrian waiting areas 300B_2 and 300B_3 adjacent to crosswalk 20A. The third determination unit 115 can determine an area surrounded by definition points DP1, DP2, and DP3 and auxiliary definition points SDP4 and SDP5 as zebra area 300B_1. In a specific example, the third determination unit 115 determines a polygon having definition points DP1, DP2, and DP3 and auxiliary definition points SDP4 and SDP5 as vertices as zebra area 300B_1.

[0087] The third determination unit 115 can determine areas obtained by extending the zebra area 300B_1 in the longitudinal direction as the waiting areas 300B_2 and 300B_3. For example, the third determination unit 115 can determine, as the waiting area 300B_3, an area that is adjacent to an edge of the zebra area 300B_1 in the longitudinal direction that does not include the auxiliary definition points SDP4 and SDP5, i.e., an edge connecting the definition points DP2 and DP3, and has a predetermined length in the longitudinal direction of the zebra area 300B_1.

[0088] Referring to FIG. 7 , the entire edge of the crosswalk 20A away from the infrastructure radio wave sensor 10 (the curve connecting endpoints P2 and P3; hereinafter, also referred to as the "remote edge") is included in the detection-guaranteed area 40. Therefore, a waiting area can be determined within the detection-guaranteed area 40 without limiting the size of the waiting area adjacent to the remote edge. Returning to FIG. 11 , the third determination unit 115 determines waiting area 300B_3 adjacent to the entire remote edge (the line segment connecting definition points DP2 and DP3) in zebra area 300B_1 that does not include auxiliary definition points SDP4 and SDP5. Hereinafter, a polygon formed by vertices N1, N2, N3, ..., Nn (n is a natural number) will be referred to as polygon N1, N2, N3, ..., Nn, and a side (line segment) connecting adjacent vertices N1 and N2 will be referred to as side (line segment) N1, N2. In one example, the third determination unit 115 determines a definition point DP21 that defines a waiting area at a position a predetermined distance away from definition point DP2, which is a vertex, on an extension line of the longitudinal sides DP1 and DP2 of the polygons DP1, DP2, DP3, SDP4, and SDP5, and determines a definition point DP31 at a position a predetermined distance away from definition point DP3, which is a vertex, on an extension line of the longitudinal sides DP3 and SDP4. The third determination unit 115 can determine the area surrounded by definition points DP2, DP21, DP31, and DP3 as waiting area 300B_3.

[0089] A portion of the near edge of the crosswalk 20A to the infrastructure radio wave sensor 10 is not included in the detection guaranteed area 40. In this case, if the size of the waiting area adjacent to the near edge is not limited, part of this waiting area will fall outside the detection guaranteed area 40. If part of the waiting area falls outside the detection guaranteed area 40, pedestrians cannot be accurately detected in this waiting area. For this reason, in the first embodiment, the third determination unit 115 determines a waiting area adjacent to the near edge, the size of which is limited. For example, the third determination unit 115 determines a waiting area adjacent to a portion of the near edge of the crosswalk 20A that is included in the detection guaranteed area 40.

[0090] 11 , the portion of the near edge of the crosswalk 20A described above that is included in the detection assurance area 40 corresponds to the sides SDP5 and DP1 of the zebra area 300B_1. In the first embodiment, the third determination unit 115 determines the waiting area 300B_2 within the detection assurance area 400, adjacent to the longitudinal edges (sides) SDP5 and DP1 of the zebra area 300B_1 that include the auxiliary definition point SDP5. For example, the third determination unit 115 determines a second definition point DP11 that defines the waiting area at a position a predetermined distance away from the definition point DP1 on an extension line of the longitudinal sides DP1 and DP2 of the polygons DP1, DP2, DP3, SDP4, and SDP5. Furthermore, the third determination unit 115 determines the intersection of a straight line that passes through the second definition point DP11 and is parallel to the sides SDP5 and DP1 with the outer edge of the detection assurance area 400 as an auxiliary definition point SDP51. The third determination unit 115 can determine the area surrounded by the definition point DP1, the second definition point DP11, the auxiliary definition point SDP51, and the auxiliary definition point SDP5 as the waiting area 300B_2. The entire waiting area 300B_2 is included in the detection assurance area 400.

[0091] Returning to FIG. 6, the setting unit 116 transmits information about the detection area 300B to the infrastructure radio wave sensor 10, and sets the detection area 300B in the infrastructure radio wave sensor 10.

[0092] The setting mode is completed when the detection area 300B is set in the infrastructure radio wave sensor 10. The infrastructure radio wave sensor 10 is started in the operation mode and performs object detection using the set detection area 300B.

[0093] 1-5. Operation of the Setting Support Device FIG. 12 is a flowchart showing an example of the setting support operation of the infrastructure radio wave sensor performed by the setting support device according to the first embodiment.

[0094] The processor 101 of the setting assistance device 100 starts up the infrastructure radio wave sensor 10 in setting mode (step S101).

[0095] When the infrastructure radio wave sensor 10 is started in the setting mode, the infrastructure radio wave sensor 10 detects an object (the object's position and speed). The infrastructure radio wave sensor 10 transmits the detection result. The processor 101 receives (acquires) the detection result transmitted from the infrastructure radio wave sensor 10 (step S102).

[0096] Based on the received detection result, the processor 101 determines a definition point for defining the crosswalk 20 (step S103). In a specific example, the processor 101 identifies a position where the object is stationary, and determines the identified stationary position as the definition point.

[0097] Based on the received detection result, the processor 101 determines an auxiliary definition point in the detection guaranteed area 400 (step S104). In a specific example, the processor 101 creates an approximation line that approximates the movement trajectory of an object that is included in the detection result and moves along the outer edge of the crosswalk 20. The processor 101 determines an auxiliary definition point at the intersection of the created approximation line and the outer edge of the detection guaranteed area 400.

[0098] The processor 101 determines the detection area 300B based on the definition points and auxiliary definition points (step S105). In a specific example, the processor 101 determines an area surrounded by the definition points and auxiliary definition points as the zebra area 300B_1. The processor 101 determines waiting areas 300B_2 and 300B_3 adjacent to the longitudinal edges of the zebra area 300B_1. In this case, the processor 101 determines the waiting area 300B_3 adjacent to the longitudinal edge (first end) of the zebra area 300B_1 that does not include the auxiliary definition points. The processor 101 determines the waiting area 300B_2 within the detection assurance area 400 adjacent to the longitudinal edge (second end) of the zebra area 300B_1 that includes the auxiliary definition points.

[0099] The processor 101 transmits data of the determined detection area 300B to the infrastructure radio wave sensor 10, and sets the detection area 300B in the infrastructure radio wave sensor 10 (step S106). This completes the setting support operation for the infrastructure radio wave sensor 10.

[0100] 2. Second Embodiment The hardware configuration of the setting assistance device according to the second embodiment is the same as the hardware configuration of the setting assistance device according to the first embodiment.

[0101] In the second embodiment, the third determination unit 115 does not determine a waiting area 300B_2 adjacent to an edge (second end) that includes an auxiliary definition point among the longitudinal edges of the zebra area 300B_1. Note that, also in the second embodiment, the third determination unit 115 determines a waiting area 300B_3 adjacent to an edge (first end) that does not include an auxiliary definition point among the longitudinal edges of the zebra area 300B_1. In other words, the third determination unit 115 determines a detection area that does not include the waiting area 300B_2 but includes the zebra area 300B_1 and the waiting area 300B_3.

[0102] Other functions of the setting assistance device according to the second embodiment are the same as those of the setting assistance device according to the first embodiment, and therefore description thereof will be omitted.

[0103] 3. Third Embodiment The hardware configuration of a setting assistance device according to a third embodiment is the same as the hardware configuration of the setting assistance device according to the first embodiment.

[0104] In the third embodiment, the second determination unit 114 determines an auxiliary definition point at the start point of a movement trajectory of an object moving from outside the detection guaranteed area 40 to inside the detection guaranteed area 40 along the outer edge of the crosswalk 20A, which is included in the detection result of the infrastructure radio wave sensor 10 acquired by the acquisition unit 111. Furthermore, the second determination unit 114 determines an auxiliary definition point at the end point of a movement trajectory of an object moving from inside the detection guaranteed area 40 to outside the detection guaranteed area 40 along the outer edge of the crosswalk 20A, which is included in the detection result acquired by the acquisition unit 111.

[0105] 13 is a diagram showing an example of determining an auxiliary definition point according to the third embodiment. A detection trajectory R4m in Fig. 13 is the detection result of the worker's movement trajectory (see Fig. 7 ) from an end point P4 outside the detection guarantee area 40 to an end point P1 inside the detection guarantee area 40. The second determination unit 114 determines an auxiliary definition point SDP5 at the starting point of the detection trajectory R4m heading from outside the detection guarantee area 400 to inside the detection guarantee area 400.

[0106] 13 is the detection result of the worker's movement trajectory (see FIG. 7) from endpoint P3 inside the detection guarantee area 40 to endpoint P4 outside the detection guarantee area 40. The second determination unit 114 determines an auxiliary definition point SDP4 at the end point of the detection trajectory R3m that heads from inside the detection guarantee area 400 to outside the detection guarantee area 400.

[0107] Other functions of the setting assistance device according to the third embodiment are the same as those of the setting assistance device according to the first embodiment, and therefore description thereof will be omitted.

[0108] [4. Supplementary Note] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, not the above-described embodiments, and includes meanings equivalent to the claims and all modifications within the scope thereof.

[0109] DESCRIPTION OF SYMBOLS 10 Infrastructure radio wave sensor 14 Transmitting / receiving unit 15a Transmitting antenna 16a Receiving antenna 17 Detection circuit 18 Housing 18a Transmitting / receiving surface 20, 20A Crosswalk 30, 30A, 30B Detection area 30_1, 30A_1, 30B_1 Zebra area 30_2, 30_3, 30A_2, 30A_3, 30B_2, 30B_3 Waiting area 31B Left end portion 31O Point 31Y Projection center axis 31X Straight line 40 Detection guaranteed area 50 Structure 51 Pole 52 Arm 60 Roadway 61 Intersection 62a Entering lane 62b Exiting lane 63a, 63b Sidewalk 100 Setting support device 101 Processor 102 Non-volatile memory 103 Volatile memory 104 Input / output interface 105 Graphic controller 106 Communication interface 107 Setting support program 108 Detection guaranteed area information 111 Acquisition unit 112 Creation unit 113 First determination unit 114 Second determination unit 115 Third determination unit 116 Setting unit 201 Input device 202 Display device 300, 300B Detection area 300_1, 300B_1 Zebra area 300_2, 300_3, 300B_2, 300B_3 Waiting area 400 Detection guaranteed area P1, P2, P3, P4 End points P5, P6 Midpoints P1m, P2m, P3m Detection points R1, R2, R3, R4 Route R1m, R2m, R3m, R4m Detection trajectory DP1, DP2, DP3, DP11, DP21, DP31 Definition points SDP4, SDP5, SDP51 Auxiliary definition points AL3, AL4 Approximation line

Claims

1. A radio wave sensor configuration support device comprising: an acquisition unit that acquires detection results by a radio wave sensor of an object moving in a target area on a road; a first determination unit that, when a first portion of the target area is included in a detection guaranteed area, which is an area where detection of an object by the radio wave sensor can be guaranteed, but a second portion of the target area is not included in the detection guaranteed area, determines a first definition point that defines the target area in the detection guaranteed area based on the detection results in the detection guaranteed area acquired by the acquisition unit; a second determination unit that determines a second definition point, different from the first definition point, that defines the first portion in the detection guaranteed area, based on the detection results in the detection guaranteed area acquired by the acquisition unit; and a third determination unit that determines a detection area, which is an area corresponding to the first portion and is an area where the radio wave sensor detects objects on the road, based on the first definition point determined by the first determination unit and the second definition point determined by the second determination unit.

2. The radio wave sensor configuration support device according to claim 1, wherein the second determination unit determines the second definition point on the outer edge of the detection guaranteed area.

3. A radio wave sensor setting assistance device as described in claim 2, further comprising a creation unit that creates an approximation line that approximates the movement trajectory of an object moving along the outer edge of the target area, the movement trajectory being included in the detection result acquired by the acquisition unit, and the second determination unit determines the second definition point at the intersection of the approximation line created by the creation unit and the outer edge of the detection guaranteed area.

4. The radio wave sensor setting support device described in claim 2, wherein the second determination unit determines the second definition point at the starting point of the movement trajectory of an object moving from outside the detection guarantee area to inside the detection guarantee area along the outer edge of the target area, and the movement trajectory is included in the detection result acquired by the acquisition unit.

5. The radio wave sensor setting support device described in claim 2, wherein the second determination unit determines the second definition point at the end point of the movement trajectory of an object moving from inside the detection guarantee area to outside the detection guarantee area along the outer edge of the target area, and the movement trajectory is included in the detection result acquired by the acquisition unit.

6. A radio wave sensor setting assistance device according to any one of claims 1 to 5, wherein the target area is a crosswalk, and the detection area includes a zebra area corresponding to the crosswalk and a waiting area for pedestrians adjacent to the crosswalk.

7. The radio wave sensor setting support device according to claim 6, wherein the third determination unit determines an area surrounded by the first definition point and the second definition point as the zebra area.

8. The radio wave sensor setting support device according to claim 7, wherein the third determination unit determines the waiting area adjacent to an end of the zebra area in the longitudinal direction.

9. A radio wave sensor setting support device as described in claim 8, wherein the third determination unit determines the waiting area adjacent to a first longitudinal end of the zebra area that does not include the second definition point, and does not determine the waiting area adjacent to a second longitudinal end of the zebra area that includes the second definition point.

10. The radio wave sensor setting support device described in claim 8, wherein the third determination unit determines the waiting area adjacent to the longitudinal end of the zebra area including the second definition point within the detection guarantee area.

11. A method for assisting in setting up a radio wave sensor, comprising: a step of acquiring detection results by a radio wave sensor of an object moving in a target area on a road; a step of determining, when a first portion of the target area is included in a detection guaranteed area, which is an area where detection of an object by the radio wave sensor can be guaranteed, but a second portion of the target area is not included in the detection guaranteed area, based on the detection results in the acquired detection guaranteed area, a first definition point that defines the target area in the detection guaranteed area; a step of determining, based on the detection results in the detection guaranteed area, a second definition point that is different from the first definition point and that defines the first portion in the detection guaranteed area; and a step of determining, based on the determined first definition point and the determined second definition point, a detection area that corresponds to the first portion and is an area for the radio wave sensor to detect objects on a road.

12. A computer program for assisting in the setting of a radio wave sensor that detects objects in a target area on a road, the computer program causing a computer to execute the following steps: acquiring detection results of the radio wave sensor for objects moving in the target area; when a first portion of the target area is included in a detection guaranteed area, which is an area where detection of objects by the radio wave sensor can be guaranteed, and a second portion of the target area is not included in the detection guaranteed area, determining a first definition point that defines the target area in the detection guaranteed area based on the detection results in the acquired detection guaranteed area; determining a second definition point, different from the first definition point, in the detection guaranteed area that defines the first portion based on the detection results in the detection guaranteed area; and determining a detection area, which is an area corresponding to the first portion and is an area where the radio wave sensor detects objects on the road, based on the determined first definition point and the determined second definition point.

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