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

Abstract

A radio wave sensor detects an object that is moving in a target area on a road. When a first portion of the target area is included in a detectable area in which an object can be detected and a second portion of the target area is not included in the detectable area, the radio wave sensor acquires a detection result of the object that is moving in the target area. In the radio wave sensor, a virtual detection area for detecting objects on the road is determined on the basis of a first definition point that is determined on the basis of the detection result and defines the first portion in the detectable area, and a second definition point that is estimated on the basis of the detection result and defines the second portion outside the detectable area.

Description

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

[0001] This disclosure relates to a radio wave sensor, a radio wave sensor configuration support method, and a computer program. This application claims priority to Japanese Application No. 2024-151665, filed September 3, 2024, and incorporates by reference all of the 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 according to an embodiment of the present disclosure detects an object moving in a target area on a road. When a detectable area in which an object can be detected includes a first portion of the target area and a second portion of the target area is not included in the detectable area, the radio wave sensor acquires a detection result of the object moving in the target area. The radio wave sensor determines a virtual detection area for detecting an object on the road based on a first definition point that is determined based on the detection result and defines the first portion within the detectable area, and a second definition point that is estimated based on the detection result and defines the second portion outside the detectable area.

[0005] FIG. 1 is a diagram illustrating an example of use of an infrastructure radio wave sensor according to a 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 block diagram illustrating an example of the hardware configuration of the infrastructure radio wave sensor according to the first embodiment. FIG. 4 is a diagram illustrating an example of setting a detection area in a sensor coordinate space. FIG. 5A is a diagram illustrating a first example of a positional relationship between a detectable area and a target area. FIG. 5B is a diagram illustrating a second example of a positional relationship between a detectable area and a target area. FIG. 6 is a block diagram illustrating an example of a hardware configuration of a setting support device according to the first embodiment. FIG. 7 is a functional block diagram illustrating an example of the functions of the setting support device according to the first embodiment. FIG. 8 is a diagram illustrating an example of a walking pattern of a worker at a crosswalk. FIG. 9 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. 8. FIG. 10 is a diagram illustrating an example of an approximation line of the movement trajectory of the worker detected by the infrastructure radio wave sensor illustrated in 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 diagram illustrating an example of a crossing time prediction line in the detection area illustrated in FIG. 11. FIG. 13 is a flowchart showing an example of the configuration support operation of an infrastructure radio wave sensor by the configuration support device according to the first embodiment. FIG. 14 is a diagram showing a first modified example of the estimation of a second definition point by the configuration support device according to the first embodiment. FIG. 15 is a diagram showing a second modified example of the estimation of a second definition point by the configuration support device according to the first embodiment. FIG. 16 is a diagram showing a third modified example of the estimation of a second definition point by the configuration support device according to the first embodiment. FIG. 17 is a diagram showing a third example of the positional relationship between a detectable area and a target area. FIG. 18 is a diagram showing an example of the estimation of a second definition point by the configuration support device according to the second embodiment. FIG. 19 is a diagram showing an example of determination of a detection area in the example of FIG. 18. FIG. 20 is a diagram showing a modified example of the estimation of a second definition point by the configuration support device according to the second 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 intended to detect objects in 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 of ​​the radio wave sensor to detect objects in the target area.

[0007] According to the present disclosure, even if part of the target area falls within an area where the radio wave sensor cannot detect objects, the detection area of ​​the radio wave sensor for detecting objects 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 according to an embodiment of the present disclosure detects an object moving in a target area on a road. When a detectable area in which an object can be detected includes a first portion of the target area and a second portion of the target area is not included in the detectable area, the radio wave sensor obtains a detection result of the object moving in the target area. The radio wave sensor determines a virtual detection area for detecting an object on the road based on a first definition point that is determined based on the detection result and defines the first portion within the detectable area, and a second definition point that is estimated based on the detection result and defines the second portion outside the detectable area. By estimating the second definition point, the radio wave sensor can reproduce the shape of the target area, a portion of which is outside the detectable area. Therefore, the radio wave sensor can appropriately set a virtual detection area for detecting an object in the target area.

[0010] (2) In the above (1), the second definition point may be estimated based on a positional condition of the second definition point. The positional condition of the second definition point is determined by the shape and position of the target area. Therefore, in the radio wave sensor, the second definition point outside the detectable area can be appropriately estimated based on such a positional condition.

[0011] (3) In the above (2), the positional condition of the second definition point may include a first condition regarding a first positional relationship between the first definition point and the second definition point. A certain positional relationship exists between the first definition point and the second definition point. Therefore, in the radio wave sensor, the second definition point outside the detectable area can be appropriately estimated based on the first condition regarding such a positional relationship.

[0012] (4) In the above (3), the first positional relationship may include a first distance between the first definition point and the second definition point. The distance between the first definition point and the second definition point is determined based on the shape and size of the target area. Therefore, in the radio wave sensor, the second definition point outside the detectable area can be appropriately estimated based on the distance between the first definition point and the second definition point.

[0013] (5) In the above (4), the first distance may be a distance between a first definition point selected from a plurality of the first definition points and the second definition point. This allows the radio wave sensor to appropriately estimate a second definition point outside the detectable area based on the distance between some of the plurality of first definition points and the second definition point.

[0014] (6) In the above (4), the target area may include a first end point that is far from the radio wave sensor and a second end point that is close to the radio wave sensor, and the first distance may be a distance between the first definition point corresponding to the second end point and the second definition point. This allows the radio wave sensor to appropriately estimate the second definition point outside the detectable area based on the distance between the first definition point corresponding to the second end point that is close to the radio wave sensor in the target area and the second definition point.

[0015] (7) In any one of (3) to (6) above, the first positional relationship may include a first direction from the first definition point to the second definition point. The direction from the first definition point to the second definition point is determined by the shape and installation orientation of the target area. Therefore, in the radio wave sensor, the second definition point outside the detectable area can be appropriately estimated based on the direction from the first definition point to the second definition point.

[0016] (8) In the above (7), the first direction may be a direction from a first definition point selected from the plurality of first definition points to the second definition point. This allows the radio wave sensor to appropriately estimate a second definition point outside the detectable area based on the direction from some of the plurality of first definition points to the second definition point.

[0017] (9) In the above (7), the target area may include a first end point distant from the radio wave sensor and a second end point close to the radio wave sensor, and the first direction may be a direction from the first definition point corresponding to the first end point to the second definition point. This allows the radio wave sensor to appropriately estimate the second definition point outside the detectable area based on the direction from the first definition point corresponding to the first end point distant from the radio wave sensor of the target area to the second definition point.

[0018] (10) In the above (2), the positional condition may include a second condition regarding a second positional relationship between the radio wave sensor and the second definition point. A certain positional relationship exists between the radio wave sensor and the second definition point. Therefore, the radio wave sensor can appropriately estimate the second definition point outside the detectable area based on the first condition regarding such a positional relationship.

[0019] (11) In the above (10), the second positional relationship may include a second distance between the radio wave sensor and the second definition point. The distance between the radio wave sensor and the second definition point is determined by the positional relationship between the radio wave sensor and the target area. Therefore, in the radio wave sensor, the second definition point outside the detectable area can be appropriately estimated based on the distance between the radio wave sensor and the second definition point.

[0020] (12) In the above (10) or (11), the second positional relationship may include a second direction from the radio wave sensor toward the second definition point. The direction from the radio wave sensor to the second definition point is determined by the positional relationship between the radio wave sensor and the target area. Therefore, the radio wave sensor can appropriately estimate the second definition point outside the detectable area based on the direction from the radio wave sensor to the second definition point.

[0021] (13) In (1) or (2) above, the target area may be a crosswalk, the crosswalk including a first endpoint that is distant from the radio wave sensor and a second endpoint that is close to the radio wave sensor, the second definition point corresponds to the second endpoint, and a line that includes the second definition point and is included in the detection area may be a crossing time prediction line that predicts the crossing time required for an object moving through the target area in a direction from the first endpoint to the second endpoint to complete crossing the target area. In this way, when a part of the crosswalk is outside the detectable area, a detection area including the crossing time prediction line is set in the radio wave sensor, so that the radio wave sensor can predict the crossing time of the object.

[0022] (14) A radio wave sensor configuration support method according to an embodiment of the present disclosure 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 detectable area in which an object can be detected includes a first portion of the target area but does not include a second portion of the target area, determining a first definition point within the detectable area based on the acquired detection results to define the first portion; estimating a second definition point outside the detectable area based on the acquired detection results to define the second portion; and determining a virtual detection area for the radio wave sensor to detect objects on the road based on the first definition point and the second definition point. By estimating the second definition point, the radio wave sensor configuration support method can reproduce the shape of a target area that is partially outside the detectable area. Therefore, the radio wave sensor configuration support method can appropriately set a detection area for detecting objects in the target area by the radio wave sensor.

[0023] (15) A computer program according to an embodiment of the present disclosure is a computer program for assisting in the configuration of a radio wave sensor that detects an object in a target area on a road. The computer program causes 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 detectable area in which an object can be detected includes a first portion of the target area but does not include a second portion of the target area, determining a first definition point within the detectable area based on the acquired detection results, the first definition point defining the first portion; estimating a second definition point outside the detectable area based on the acquired detection results, the second definition point defining the second portion; and determining a virtual detection area in which the radio wave sensor detects an object on the road based on the determined first definition point and the estimated second definition point. By estimating the second definition point, the computer program can reproduce the shape of the target area, a portion of which falls outside the detectable area. Thus, the computer program allows the radio wave sensor to appropriately set a detection area for detecting an object in the target area.

[0024] The present disclosure can be realized not only as a radio wave sensor having the above-described characteristic configuration, a radio wave sensor setting support method having characteristic processing steps, and a computer program for causing a setting support device to execute the characteristic processing, but also as a radio wave sensor setting support device, a semiconductor integrated circuit as part or all of the radio wave sensor setting support device, or a system that includes a radio wave sensor setting support device as part of it.

[0025] <Details of Embodiments of the Present Disclosure> Hereinafter, details of each embodiment 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.

[0026] [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 (not shown) 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.

[0027] 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.

[0028] The infrastructure radio wave sensor 10 is attached to a structure 50 provided on the sidewalk 63b. The structure 50 is several meters tall, and the infrastructure radio wave sensor 10 is installed several meters above ground level. 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.

[0029] 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. FIG. 2 is a perspective view showing an example of the exterior configuration of the infrastructure radio wave sensor 10 according to the first embodiment. For example, as shown in FIG. 2 , the infrastructure radio wave sensor 10 includes a housing 18 having at least one transmitting / receiving surface 18a 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 via the transmitting / receiving surface 18a. The modulated waves hit an object and are reflected, and the receiving antenna 16a receives the reflected waves via the transmitting / receiving surface 18a. The transmitting / receiving unit 14 and the detection circuit 17 perform signal processing on the modulated wave signal and the reflected 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.

[0030] Specifically, the infrastructure radio wave sensor 10 is positioned so that a straight line (hereinafter also referred to as the "projection central axis") obtained by projecting a normal line of the transmission / reception surface 18a that transmits and receives radio waves from the center of the transmission / reception surface 18a 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 an 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 central axis.

[0031] FIG. 3 is a block diagram showing an example of the hardware configuration of the infrastructure radio wave sensor according to the first embodiment. The infrastructure radio wave sensor 10 includes a processing circuit (circuitry) including at least one processor 11. The circuitry may be configured with, in addition to the processor 11, at least one memory 13, and circuits such as an integrated circuit combining various analog circuits and various digital circuits. The processing circuit may include a transmission circuit 15, a reception circuit 16, and the aforementioned detection circuit 17 (not shown in FIG. 3 ). The transmission circuit 15 includes a transmission antenna 15a of the transceiver 14. The reception circuit 16 includes a reception antenna 16a of the transceiver 14. The memory 13 stores program code that causes the processor to execute functions. The processor 11 may execute functions according to program code read from the memory, or may execute functions according to a logic circuit designed in advance to execute the functions. The processor 11 may be any of various processors suitable for computer control, such as a CPU (Central Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). Note that multiple physically separated processors may cooperate with each other to execute functions. For example, processors installed in multiple physically separated computers may cooperate with each other to execute functions via a network such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet. The program may be installed into memory from an external server device or the like via a network, or may be distributed in a state stored on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a semiconductor memory, and then installed into memory from the recording medium.

[0032] The infrastructure radio wave sensor 10 further includes a communication interface (communication I / F) 19. The communication I / F 19 can communicate with an external device. The communication I / F 19 is connected to a setting assistance device (described later) via a cable. The infrastructure radio wave sensor 10 can transmit detection result data to the setting assistance device through the communication I / F 19. The communication I / F 19 is a wireless communication interface, and may communicate with the setting assistance device wirelessly.

[0033] The infrastructure radio wave sensor 10 further includes a nonvolatile memory 12. The nonvolatile memory 12 stores setting information 121 for the infrastructure radio wave sensor. The setting information 121 includes information related to the detection area of ​​the infrastructure radio wave sensor, which will be described later.

[0034] [1-2. Detection Area] In the infrastructure radio wave sensor 10, a virtual detection area corresponding to a target area, which is a range on the road (ground surface) for detecting an object, is set by a setting support device, which will be described later. In FIG. 1, the target area 30 is shown as if the target area exists in the real space on the ground surface. The detection area is information that is set within the infrastructure radio wave sensor 10. Based on the set detection area, the infrastructure radio wave sensor 10 can identify the position, speed, etc. of the detected object on the road.

[0035] The target area does not have to include only the crosswalk area. For example, an infrastructure radio wave sensor 10 used to control traffic signals installed near a crosswalk 20 is required not only to measure and detect the number of pedestrians and bicycles (including riders; hereinafter, pedestrians and bicycles will be simply referred to as "pedestrians") crossing the crosswalk 20, but also to detect pedestrians waiting to cross on the sidewalk adjacent to the crosswalk 20. In this case, for example, the target 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 target 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).

[0036] 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 will also be referred to as a "sensor coordinate space."

[0037] In the infrastructure radio wave sensor 10, a detection area 300 is set in the sensor coordinate space in order to detect an object on the crosswalk 20.

[0038] FIG. 4 is a diagram for explaining an example of setting a virtual detection area 300 in the sensor coordinate space.

[0039] 4, in the real space of the ground surface, 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 through the point 31O.

[0040] For example, the sensor coordinate space is a two-dimensional coordinate space corresponding to the real space of 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 a point 31O in the real space. The Y axis of the sensor coordinate space corresponds to a projection center axis 31Y in the real space. The X axis of the sensor coordinate space corresponds to a line 31X in the real space.

[0041] A virtual detection area 300 corresponding to a target area 30 in real space is set in the sensor coordinate space of the infrastructure radio wave sensor 10. The target area 30 is an area that includes, for example, a crosswalk 20.

[0042] For example, the target 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. In this embodiment, a zebra area is given as an example of the crosswalk 20, but this is not limiting. Crosswalks without stripes like zebras are also included in the crosswalk 20.

[0043] 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.

[0044] The infrastructure radio wave sensor 10 has a detectable area 40 (see FIG. 1 ). The detectable area 40 is an area where the infrastructure radio wave sensor 10 can guarantee detection of an object. The detectable 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 detectable 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 detectable area 40 is formed, for example, in a fan shape centered on the projection central axis. For example, the detectable 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.

[0045] The target area 30 may be set as part of the detectable area 40 of the infrastructure radio wave sensor 10. In other words, the detectable area 40 may cover the entire target area 30. The target area 30 is, for example, an area that includes at least a part of the crosswalk 20. In another example, the target area 30 may be an area that includes a first part that is included in the detectable area 40 of the infrastructure radio wave sensor 10 and a second part that is not included in the detectable area 40. In other words, the detectable area 40 does not have to cover part (the second part) of the target area 30.

[0046] 5A is a diagram showing a first example of the positional relationship between the detectable area and the target area. In Fig. 5A, the entire crosswalk 20A is included in the detectable area 40. In the example of Fig. 5A, an object (pedestrian) on the crosswalk 20 can be detected by the infrastructure radio wave sensor 10.

[0047] In the example of FIG. 5A , the detectable area 40 covers the entire crosswalk 20A. Specifically, the detectable area 40 covers a range that includes the entire crosswalk 20A and portions of sidewalks 63a and 63b adjacent to the crosswalk 20A. When the detectable area 40 includes the crosswalk 20A as in FIG. 5A , a target area 30A that includes the entire crosswalk 20A can be set. More specifically, in the example of FIG. 5A , the target area 30A includes a zebra area 30A_1 that corresponds to the crosswalk 20A and waiting areas 30A_2 and 30A_3 that correspond 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 detectable area 40.

[0048] 5B is a diagram showing a second example of the positional relationship between the detectable area and the target area. In Fig. 5B, the entire crosswalk 20A is not included in the detectable area 40, and part of the crosswalk 20A is outside the detectable area 40. In the example of Fig. 5B, an object (pedestrian) in part of the crosswalk 20A cannot be detected by the infrastructure radio wave sensor 10.

[0049] 5B , when the detectable area 40 does not include a portion of the crosswalk 20A, setting a target area that includes the entire crosswalk 20A may result in inaccurate detection of pedestrians present in portions of the crosswalk 20A that are outside the detectable area 40. However, setting a target area in this manner has the advantage of enabling all pedestrians present in the crosswalk 20A within the detectable area 40 to be detected. In the present disclosure, when the detectable area 40 does not include a portion of the crosswalk 20A, a target area 30B is set regardless of whether the pedestrian is within or outside the detectable area 40. In other words, the target area 30B includes the entire crosswalk 20A. The target area 30B includes a first portion of the crosswalk 20A that is included in the detectable area 40 and a second portion of the crosswalk 20A that is not included in the detectable area 40.

[0050] 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 detectable area 40. In the example of FIG. 5B , 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 detectable area 40.

[0051] 5B , target area 30B is outside detectable area 40 at the left end portion of crosswalk 20A on the side closer to infrastructure radio wave sensor 10. In other words, target area 30B includes zebra area 30B_1 that is outside the detectable area at the left end portion of crosswalk 20A on the side closer to infrastructure radio wave sensor 10.

[0052] 5B , the portion of the sidewalk 63a away from the infrastructure radio wave sensor 10 adjacent to the crosswalk 20A is included in the detectable area 40. Therefore, in the example of FIG. 5B , similar to the example of FIG. 5A , the target area 30B includes a waiting area 30B_3 that corresponds to the portion of the sidewalk 63a away from the infrastructure radio wave sensor 10 adjacent to the crosswalk 20A.

[0053] In the example of FIG. 5B , the detectable area 40 is not large enough to set a waiting area on the sidewalk 63b 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 detectable area 40. A portion of the sidewalk 63b adjacent to the crosswalk 20A that is not included in the detectable area 40 is outside the detectable area 40. In such a case, even if a waiting area is set on the sidewalk 63b, pedestrians in the waiting area cannot be accurately detected. For this reason, in the first embodiment, when a portion of the crosswalk 20A is outside the detectable area 40, a waiting area is not set on the sidewalk 63b adjacent to that portion. In other words, the target area 30B does not include a waiting area on the sidewalk 63b close to the infrastructure radio wave sensor 10.

[0054] [1-3. Configuration of the Setting Support Device] FIG. 6 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 300 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 (I / O) 104, a graphics controller 105, and a communication interface (communication I / F) 106. The setting support device 100 may further include an input device 201 and a display device 202. 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. The setting support device 100 may be provided in the housing of the infrastructure radio wave sensor 10 or may be provided separately from the infrastructure radio wave sensor 10.

[0055] When the configuration assistance device 100 is provided remotely from the infrastructure radio wave sensor 10, the configuration assistance device 100 may be configured as, for example, a terminal such as a laptop computer, tablet, or smartphone that includes a processor 101, a nonvolatile memory 102, and a volatile memory 103 and is electrically connected to the infrastructure radio wave sensor 10. The volatile memory 103 is, for example, a semiconductor memory such as an SRAM (Static Random Access Memory) or a DRAM (Dynamic Random Access Memory). The nonvolatile memory 102 is, for example, a flash memory, a hard disk, or a ROM (Read Only Memory). The nonvolatile memory 102 stores a configuration assistance program 107, which is a computer program, and data used to execute the configuration assistance program 107. Each function of the configuration assistance device 100 is realized when the processor 101 executes the configuration assistance program 107. The setting assistance program 107 can be stored in a recording medium such as a flash memory, a ROM, a CD-ROM, etc. 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] For example, the nonvolatile memory 102 stores detectable area information 108, which is position information of a detectable area 400 (see FIG. 9 , etc., described later) of the infrastructure radio wave sensor 10 in the sensor coordinate space. The detectable area 400 in the sensor coordinate space corresponds to the detectable area 40 in real space. For example, the detectable area information 108 is information indicating the outer edge of the detectable area 400.

[0061] [1-4. Functions of the Setting Support Device] When a part of the crosswalk 20A is outside the detectable area 40, as in the example shown in FIG. 5B , the setting support device 100 according to the first embodiment corresponds to a target area 30B that includes a first part that is included in the detectable area 40 and a second part that is not included in the detectable area 40, and supports setting a detection area in the infrastructure radio wave sensor 10.

[0062] 7 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, an estimation unit 114, a second determination unit 115, and a setting unit 116.

[0063] 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.

[0064] 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.

[0065] In the setting mode, the infrastructure radio wave sensor 10 detects an object moving in the target area 30B in order to set the 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.

[0066] 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.

[0067] 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.

[0068] 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. 7 , 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] For example, a worker walks in a specific pattern on the crosswalk 20A in place of a moving object such as a pedestrian. FIG. 8 shows an example of a walking pattern of a worker on the crosswalk. In a 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. Upon reaching the right endpoint P2, the worker stops at the right 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. Upon reaching the endpoint P3, the worker stops at the left 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.

[0073] 8, the projection center axis 31Y of the infrastructure radio wave sensor 10 is parallel to the side edges P3 and P4 of the crosswalk 20A. The projection center axis 31Y of the infrastructure radio wave sensor 10 is also parallel to the side edges P1 and P2 of the crosswalk 20A.

[0074] Fig. 9 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. 8. For example, as shown in Fig. 9, the detection result of the movement trajectory of the worker by the infrastructure radio wave sensor 10 may be displayed on the display device 202. Furthermore, as shown in Fig. 9, the setting assistance device 100 may use the detectable area information 108 to display a detectable area 400 superimposed on the movement trajectory of the worker. This allows the user to understand the positional relationship between the detectable area 400 and the movement trajectory of the worker.

[0075] 9 , 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] Referring to FIG. 8 , the left end portion of the crosswalk 20 on the proximity side of the infrastructure radio wave sensor 10 is outside the detectable area 40. In other words, part of route R3, part of route R4, and endpoint P4 are not included in the detectable area 40. Returning to FIG. 9 , the worker is not detected in areas outside the detectable area 40. In other words, 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 detectable 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 detectable area 40. The part of route R3 along which the worker traveled that is not included in the detectable area 40, the part of route R4 along which the worker traveled that is not included in the detectable area 40, and endpoint P4 where the worker stopped are not included in the detection result of the infrastructure radio wave sensor 10. That is, the detected trajectory R3m in Figure 9 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.

[0082] 7 , 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. 9 , 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.

[0083] FIG. 10 is a diagram illustrating an example of an approximation line of the movement trajectory of a worker detected by the infrastructure radio wave sensor shown in FIG. 9 . For example, the creation unit 112 creates an approximation line AL3 of the detection trajectory R3m of an object moving from within the detectable area 400 to outside the detectable area 400, among the detection trajectories R1m, R2m, R3m, and R4m along the outer edge of the crosswalk 20. A portion of the route R3 shown in FIG. 8 falls outside the detectable area 400. The detection trajectory R3m corresponding to such route R3 is discontinued at the portion outside the detectable area 400. The route R3 continues to an endpoint P4 outside the detectable area 40. Therefore, the endpoint P4 is expected to exist on an extension of the detection trajectory R3m. The creation unit 112 creates the approximation line AL3 to estimate the position (second definition point) of the endpoint P4 outside the detectable area 40. The estimation of the second definition point will be described later.

[0084] A detection trajectory R3m of an object moving from inside the detectable area 400 to outside the detectable area 400 has an end point at or near the outer edge of the detectable area 400. That is, the creation unit 112 determines whether or not each of the detection trajectories R1m, R2m, R3m, and R4m is a detection trajectory that has an end point at or near the outer edge of the detectable area 400, and can create an approximation line AL3 of the detection trajectory R3m that has an end point at or near the outer edge of the detectable area 400.

[0085] A portion of the route R4 shown in FIG. 8 also falls outside the detectable area 40. Referring to FIG. 9, the detection trajectory R4m corresponding to such route R4 is discontinued at the portion that falls outside the detectable area 400. The route R4 also continues to an end point P4 that is outside the detectable area 400. Therefore, it is expected that the end point P4 exists on an extension of the detection trajectory R4m. The creation unit 112 may create an approximation line of the detection trajectory R4m of an object moving from outside the detectable area 400 into the detectable area 400, instead of or in addition to the approximation line of the detection trajectory R3m. The detection trajectory R4m of an object moving from outside the detectable area 400 into the detectable area 400 has a starting point at or near the outer edge of the detectable 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 its starting point on or near the outer edge of the detectable area 400, and can create an approximation line of the detection trajectory R4m that has its starting point on or near the outer edge of the detectable area 400.

[0086] Returning to FIG. 7 , when the detectable area 40 includes a first portion of the crosswalk 20 but does not include a second portion of the crosswalk 20, a first definition point that defines the first portion within the detectable area 40 is determined based on the detection results acquired by the acquisition unit 111. Reference is made to FIG. 10 . FIG. 10 shows an example of how the setting assistance device according to the first embodiment determines the first definition point. For example, the first definition point is an end point of the first portion of the crosswalk 20 (the portion of the crosswalk 20 that is included in the detectable area 40). For example, if the crosswalk 20 is a polygon, the first definition point is a vertex of the polygon. If the crosswalk 20 is a shape in which some sides of the polygon are curved (for example, the crosswalk 20A shown in FIG. 8 ), the first definition point is an intersection (vertex) of two straight lines that constitute the shape, an intersection of a straight line and a curve that constitute the shape, or an intersection of two curves that constitute the shape. For example, the first definition point may include a point midway along one side of the polygon that is the crosswalk 20 , or may include a point midway along a curve that forms the shape of the crosswalk 20 .

[0087] 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 the first definition point, the position (e.g., the average value of multiple detection positions) of an object detected at the same or nearby position during a certain period (e.g., a period during which the object is stopping). In the example of Fig. 10, the detection point P1m shown in Fig. 9 is determined as the first definition point DP1, the detection point P2m is determined as the first definition point DP2, and the detection point P3m is determined as the first definition point DP3.

[0088] Returning to FIG. 7 , the estimation unit 114 estimates a second definition point that defines a second portion outside the detectable area 40 based on the detection result acquired by the acquisition unit 111. The second definition point is a point different from the first definition point. See FIG. 10 . For example, the second definition point is an end point of the second portion of the crosswalk 20 (a portion of the crosswalk 20 that is not included in the detectable area 40). For example, if the crosswalk 20 is a polygon, the second definition point is a vertex 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. 8 ), the second definition point is an intersection (vertex) of two lines that make up the figure, an intersection of a line and a curve that make up the figure, or an intersection of two curves that make up the figure. For example, the second definition point 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.

[0089] The second definition point will be described in more detail with reference to Figure 8. In the example of Figure 8, endpoints P1, P2, and P3 of the crosswalk 20A are first definition points, and endpoint P4 is the second definition point. Point P5 on the left edge of the crosswalk 20A (the line segment connecting endpoint P3 and endpoint P4) is the intersection point between the left edge of the crosswalk 20A and the outer edge of the detectable area 40. Point P6 on the edge of the crosswalk 20A close to the infrastructure radio wave sensor 10 (the curve connecting endpoint P4 and endpoint P1; hereinafter, also referred to as the "close edge") is the intersection point between the close edge of the crosswalk 20A and the outer edge of the detectable area 40.

[0090] Points P5 and P6 are located on the outer edge of the detectable area 40, that is, on the boundary between the inside and outside of the detectable area 40.

[0091] A first portion of the crosswalk 20A that is included in the detectable area 40 is the area surrounded by the endpoints P1, P2, P3 and points P5 and P6. A second portion of the crosswalk 20A that is not included in the detectable area 40 is the area surrounded by the endpoint P4 and points P5 and P6.

[0092] 7 , for example, the estimation unit 114 estimates the second definition point based on the positional condition of the second definition point. For example, the position of the endpoint of the crosswalk 20 (the relative position with respect to the infrastructure radio wave sensor 10) is determined by the shape of the crosswalk 20, the size of the crosswalk 20, or the orientation of the crosswalk 20 with respect to the infrastructure radio wave sensor 10. Therefore, the estimation unit 114 can estimate the position of the second definition point based on the positional condition of the second definition point that is determined based on at least one of the shape of the crosswalk 20, the size of the crosswalk 20, and the orientation of the crosswalk 20 with respect to the infrastructure radio wave sensor 10.

[0093] For example, the positional condition includes a first condition regarding a first positional relationship between the first definition point and the second definition point determined by the first determination unit 113. The positional relationship between the first definition point and the second definition point (first positional relationship) is determined based on at least one of the shape of the crosswalk 20, the size of the crosswalk 20, and the orientation of the crosswalk 20 with respect to the infrastructure radio wave sensor 10. Based on this first positional relationship, the estimation unit 114 can estimate the second definition point from the already determined first definition point. For example, the estimation unit 114 may estimate the second definition point based on at least two positional relationships. By combining multiple positional relationships, the estimation unit 114 can accurately estimate the position of the second definition point.

[0094] In a specific example, the first positional relationship includes a first distance between a first definition point and a second definition point. For example, the distance (first distance) between the first definition point and the second definition point is determined based on the shape and size of the crosswalk 20. The first distance may be the distance between a first definition point and a second definition point selected from a plurality of first definition points. With reference to FIG. 10 , for example, the first definition point DP1 may be selected from the plurality of first definition points DP1, DP2, and DP3.

[0095] 8, for example, a user can actually measure the distance from endpoint P1 to endpoint P4 and input the measured value into the setting assistance device 100. Referring to FIG. 10, the input measured value corresponds to a distance Dst1 between a first definition point DP1 corresponding to endpoint P1 and a second definition point corresponding to endpoint P4. That is, the first condition is that the second definition point EDP4 is a point separated by the distance Dst1 (first distance) from the first definition point DP1. The estimation unit 114 estimates the second definition point EDP4 based on the distance Dst1 from the first definition point DP1.

[0096] For example, the first positional relationship includes a first direction from the first definition point to the second definition point. For example, the direction from the first definition point to the second definition point (first direction) is determined based on the shape of the crosswalk 20 and the orientation of the crosswalk 20 relative to the infrastructure radio wave sensor 10. The first direction may be a direction from a first definition point selected from multiple first definition points to a second definition point. With reference to FIG. 10 , for example, the first definition point DP3 may be selected from the multiple first definition points DP1, DP2, and DP3. In other words, the first direction is a direction from the first definition point DP3 corresponding to the endpoint P3 (see FIG. 8 ) far from the infrastructure radio wave sensor 10 to the second definition point corresponding to the endpoint P4 (see FIG. 8 ) close to the infrastructure radio wave sensor 10.

[0097] Referring to FIG. 8 , the direction from endpoint P3 to endpoint P4 is the direction along route R3. Returning to FIG. 10 , it is expected that a second definition point exists along approximation line AL3 from first definition point DP3. Therefore, the estimation unit 114 estimates the second definition point using approximation line AL3. That is, the first condition is that second definition point EDP4 exists along approximation line AL3 from first definition point DP3. In the first embodiment, the estimation unit 114 estimates the second definition point EDP4 based on the distance Dst1 from the first definition point DP1 and the direction along approximation line AL3 from the first definition point DP3. Specifically, the estimation unit 114 estimates the intersection of a circle C1 centered on the first definition point DP1 and the approximation line AL3 created by the creation unit 112 as the second definition point EDP4.

[0098] Returning to Figure 7, the second determination unit 115 determines the detection area 300B corresponding to the crosswalk 20A based on the first definition points DP1, DP2, and DP3 determined by the first determination unit 113 and the second definition point EDP4 estimated by the estimation unit 114.

[0099] 11 is a diagram showing an example of determining the detection area in the example of FIG. 10. As shown in FIG. 11, for example, the detection area 300B includes a zebra area 300B_1 corresponding to the crosswalk 20A and a pedestrian waiting area 300B_3 adjacent to the crosswalk 20A. The second determination unit 115 can determine the area surrounded by the first definition points DP1, DP2, DP3 and the second definition point EDP4 as the zebra area 300B_1. In a specific example, the second determination unit 115 determines a polygon having the first definition points DP1, DP2, DP3 and the second definition point EDP4 as the zebra area 300B_1.

[0100] The second determination unit 115 may determine, as the waiting area 300B_3, an area obtained by extending the zebra area 300B_1 in the longitudinal direction. For example, the second determination unit 115 may 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 second definition point EDP4, i.e., an edge connecting the first definition points DP2 and DP3, and has a predetermined length in the longitudinal direction of the zebra area 300B_1.

[0101] Referring to FIG. 8 , the entire edge of the crosswalk 20A that is farthest from the infrastructure radio wave sensor 10 (the curve connecting the endpoints P2 and P3; hereinafter, also referred to as the "far edge") is included in the detectable area 40. Therefore, a waiting area can be determined within the detectable area 40 without limiting the size of the waiting area adjacent to the far edge. Returning to FIG. 11 , the second determination unit 115 determines waiting area 300B_3 that is adjacent to the entire far edge (the line segment connecting the first definition points DP2 and DP3) in the zebra area 300B_1 that does not include the second definition point EDP4. 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 second determination unit 115 determines a third definition point DP21 that defines the waiting area at a position a predetermined distance away from the vertex DP2 on an extension line of the sides DP1 and DP2 that extend in the longitudinal direction of the polygon DP1, DP2, DP3, and EDP4, and determines a third definition point DP31 at a position a predetermined distance away from the vertex DP3 on an extension line of the sides DP3 and EDP4 that extend in the longitudinal direction. The second determination unit 115 can determine the area surrounded by the first definition point DP2, the third definition point DP21, the third definition point DP31, and the first definition point DP3 as the waiting area 300B_3.

[0102] A portion of the edge of the crosswalk 20A near the infrastructure radio wave sensor 10 is not included in the detectable area 40. In this case, a portion of the waiting area adjacent to the near edge falls outside the detectable area 40. If a portion of the waiting area falls outside the detectable area 40, pedestrians cannot be accurately detected in this waiting area. For this reason, in the first embodiment, the second determination unit 115 does not determine a waiting area adjacent to a near edge that falls partially outside the detectable area 40.

[0103] 11 , the near edge of the crosswalk 20A described above corresponds to the sides EDP4, DP1 of the zebra area 300B_1. A portion of the side EDP4, DP1 including the second definition point EDP4 is outside the detectable area 400. The second determination unit 115 does not determine a waiting area adjacent to the side EDP4, DP1 including the second definition point EDP4.

[0104] Returning to FIG. 7 , the second determination unit 115 can determine a detection area that includes the crossing time prediction line. FIG. 12 is a diagram illustrating an example of the crossing time prediction line in the detection area shown in FIG. 11 . Parts of the sides DP1 and EDP4 of the detection area 300B (corresponding to the portions between the endpoints P1 and P6 in FIG. 8 ) are included in the detectable area 400. Therefore, the infrastructure radio wave sensor 10 can detect a pedestrian passing through the portion of the pedestrian crossing 20A between the endpoints P1 and P6. On the other hand, parts of the sides DP1 and EDP4 of the detection area 300B that correspond to the portions between the endpoints P4 and P6 in FIG. 8 are not included in the detectable area 400. Therefore, the infrastructure radio wave sensor 10 cannot detect a pedestrian passing through the portion of the pedestrian crossing 20A between the endpoints P4 and P6.

[0105] For example, the second determination unit 115 determines the line DP1, EDP4 including the second definition point EDP4 in the detection area 300B as the crossing time prediction line. The crossing time is the time it takes for a pedestrian on the crosswalk 20A to complete crossing the crosswalk 20A. More specifically, the crossing time is the time it takes for an object (pedestrian) moving across the crosswalk 20A in the direction from the first definition point toward the second definition point to complete crossing the crosswalk 20A. In the example of FIG. 12 , a pedestrian TP1 detected by the infrastructure radio wave sensor 10 moves from the first definition point DP3 toward the second definition point EDP4. The infrastructure radio wave sensor 10 detects the movement direction (indicated by the dashed arrow in the figure) and movement speed of the pedestrian TP1. The movement direction of the pedestrian TP1 is from the first definition point DP3 toward the second definition point EDP4. The infrastructure radio wave sensor 10 predicts the crossing time required for the pedestrian TP1 to reach the point ETP1 on the crossing time prediction line DP1, EDP4 based on the current position, moving direction, and moving speed of the pedestrian TP1.

[0106] "Moving in the direction from the first definition point DP3 to the second definition point EDP4" does not only mean moving along the straight line connecting the first definition point DP3 and the second definition point EDP4, but also includes moving in a direction that includes a component of the direction from the first definition point DP3 to the second definition point EDP4. In other words, the crossing time prediction lines DP1 and EDP4 are also used to predict the crossing time of a pedestrian moving in a direction inclined to the straight line connecting the first definition point DP3 and the second definition point EDP4 (however, in a direction approaching the crossing time prediction lines DP1 and EDP4).

[0107] Returning to FIG. 7, 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.

[0108] 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.

[0109] 1-5. Operation of the Setting Support Device FIG. 13 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.

[0110] The processor 101 of the setting assistance device 100 starts up the infrastructure radio wave sensor 10 in setting mode (step S101).

[0111] 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).

[0112] Based on the received detection result, the processor 101 determines a first definition point for defining a first portion of 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 first definition point.

[0113] Based on the received detection result, the processor 101 estimates a second definition point that defines a second portion of the crosswalk 20 (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 also creates a circle that has the first definition point as its center and the distance between the first definition point and the second definition point input by the user as its radius. The processor 101 estimates the intersection of the approximation line and the circle as the second definition point.

[0114] The processor 101 determines the detection area 300B based on the first definition point and the second definition point (step S105). In a specific example, the processor 101 determines an area surrounded by the first definition point and the second definition point as the zebra area 300B_1. The processor 101 determines the waiting area 300B_3 adjacent to the longitudinal edge of the zebra area 300B_1. In this case, the processor 101 determines the waiting area 300B_3 adjacent to a first longitudinal edge of the zebra area 300B_1 that does not include the second definition point. The processor 101 does not determine a waiting area adjacent to a second longitudinal edge of the zebra area 300B_1 that includes the second definition point.

[0115] Furthermore, the processor 101 determines the line DP1, EDP4 including the second definition point EDP4 in the detection area 300B as the crossing time prediction line.

[0116] 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.

[0117] [1-6. Modifications] In the first embodiment described above, the second definition point EDP4 is estimated based on the first direction from the first definition point DP3 (i.e., the approximation line AL3) and the first distance from the first definition point DP1 (i.e., the circle C1), but this is not limiting.

[0118] 14 is a diagram showing a first modified example of estimation of the second definition point by the setting assistance device according to the first embodiment. The positional condition of the second definition point may include a second condition regarding a second positional relationship between the infrastructure radio wave sensor 10 and the second definition point, instead of or in addition to the first condition regarding the first positional relationship between the first definition point and the second definition point determined by the first determination unit 113.

[0119] In a specific example, the second positional relationship includes a second distance between the infrastructure radio wave sensor 10 and the second definition point. For example, the distance (second distance) between the infrastructure radio wave sensor 10 (more specifically, the vertical projection position of the infrastructure radio wave sensor 10 onto the ground (horizontal plane)) and the second definition point is determined based on the relative positional relationship between the infrastructure radio wave sensor 10 and the crosswalk 20, and the shape and size of the crosswalk.

[0120] 8 , for example, a user can actually measure the distance from a position directly below the infrastructure radio wave sensor 10 to the endpoint P4 and input the measurement value into the setting assistance device 100. Referring to FIG. 14 , the input measurement value corresponds to the distance Dst2 between the origin O of the sensor coordinate space and the second definition point corresponding to the endpoint P4. That is, the second condition is that the second definition point EDP4 is a point that is separated from the origin O of the sensor coordinate space by the distance Dst2 (second distance). The estimation unit 114 estimates the second definition point EDP4 based on the distance Dst2 from the origin O.

[0121] For example, the estimation unit 114 may estimate the second definition point EDP4 by combining the first condition and the second condition. In the example of FIG. 14 , the first condition is that the second definition point EDP4 exists in a direction along the approximation line AL3 from the first definition point DP3. In a first modification, the estimation unit 114 estimates the second definition point EDP4 based on the distance Dst2 from the infrastructure radio wave sensor 10 and the direction along the approximation line AL3 from the first definition point DP3. Specifically, the estimation unit 114 estimates the intersection of a circle C2 centered on the origin O and the approximation line AL3 created by the creation unit 112 as the second definition point EDP4.

[0122] The second positional relationship between the infrastructure radio wave sensor 10 and the second definition point may include a positional relationship other than the second distance between the infrastructure radio wave sensor 10 and the second definition point. For example, the second positional relationship may include a direction (second direction) from the infrastructure radio wave sensor 10 (more specifically, the vertical projection position of the infrastructure radio wave sensor 10 onto the ground (horizontal plane)) toward the second definition point. For example, the user measures the direction from a position directly below the infrastructure radio wave sensor 10 to the endpoint P4. Specifically, the user measures the angle between the projection center axis 31Y and a line connecting the position directly below the infrastructure radio wave sensor 10 and the endpoint P4, and inputs the measured angle to the setting assistance device 100. The estimation unit 114 estimates the intersection of the angle-inclined line input from the Y axis and the approximation line AL3 as the second definition point EDP4.

[0123] 15 is a diagram showing a second modified example of the estimation of the second definition point by the setting support device according to the first embodiment. In the second modified example, the first positional relationship includes the direction from the first definition point DP3 to the second definition point EDP4 and the direction from the first definition point DP1 to the second definition point EDP4. As described above, the direction from the first definition point DP3 to the second definition point EDP4 is the direction from the first definition point DP3 along the approximation line AL3.

[0124] For example, as described above, the creation unit 112 creates an approximation line AL4 of the detection trajectory R4m of an object moving from outside the detectable area 400 to inside the detectable area 400. The direction from the first definition point DP1 to the second definition point EDP4 is the direction from the first definition point DP1 along the approximation line AL4.

[0125] The first condition in the second modified example is that the second definition point EDP4 exists in the direction along the approximation line AL3 from the first definition point DP3, and that the second definition point EDP4 exists in the direction along the approximation line AL4 from the first definition point DP1. In the second modified example, the estimation unit 114 estimates the second definition point EDP4 based on the direction along the approximation line AL3 from the first definition point DP3 and the direction along the approximation line AL4 from the first definition point DP1. Specifically, the estimation unit 114 estimates the intersection of the approximation line AL3 created by the creation unit 112 and the approximation line AL4 created by the creation unit 112 as the second definition point EDP4.

[0126] 16 is a diagram showing a third modified example of the estimation of the second definition point by the setting support device according to the first embodiment. In the third modified example, the first positional relationship includes the direction (first direction) from the first definition point DP3 to the second definition point EDP4 and the distance (first distance) between the first definition point DP3 and the second definition point EDP4. As described above, the direction from the first definition point DP3 to the second definition point EDP4 is the direction from the first definition point DP3 along the approximation line AL3.

[0127] In the third modified example, the first distance is a distance Dst3 between a first definition point DP3 selected from a plurality of first definition points DP1, DP2, and DP3 and a second definition point EDP4.

[0128] 8, for example, a user can actually measure the distance from endpoint P3 to endpoint P4 and input the measured value into the setting assistance device 100. Referring to FIG. 16, the input measured value corresponds to a distance Dst3 between a first definition point DP3 corresponding to endpoint P3 and a second definition point corresponding to endpoint P4. That is, the first condition is that the second definition point EDP4 is a point separated from the first definition point DP3 by a distance Dst3 (first distance). The estimation unit 114 estimates the second definition point EDP4 based on the distance Dst3 from the first definition point DP3.

[0129] 16 , the estimation unit 114 estimates the second definition point EDP4 based on the distance Dst3 from the first definition point DP3 and the direction along the approximation line AL3 from the first definition point DP3. Specifically, the estimation unit 114 estimates, as the second definition point EDP4, a point that is the distance Dst3 from the first definition point DP3 in the direction along the approximation line AL from the first definition point DP3.

[0130] 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.

[0131] 17 is a diagram showing a third example of the positional relationship between the detectable area and the target area. In Fig. 17, the entire crosswalk 20A is not included in the detectable area 40, and part of the crosswalk 20A is outside the detectable area 40. In the example of Fig. 17, an object (pedestrian) in part of the crosswalk 20A cannot be detected by the infrastructure radio wave sensor 10.

[0132] 17 , target area 30B includes edges P1, P4 (near edges) of crosswalk 20A on the side closest to infrastructure radio wave sensor 10, i.e., the entire portion of sidewalk 63b adjacent to crosswalk 20A that is close to infrastructure radio wave sensor 10, outside detectable area 40. In other words, target area 30B includes zebra area 30B_1 that is outside the detectable area in the entire edge P1, P4 of crosswalk 20A on the side closest to infrastructure radio wave sensor 10.

[0133] 17 , the adjacent portion (separate edges P2, P3) of the crosswalk 20A on the sidewalk 63a that is distant from the infrastructure radio wave sensor 10 is included in the detectable area 40. Therefore, in the example of FIG. 17 , similar to the example of FIG. 5A , the target area 30B includes a waiting area 30B_3 that corresponds to the adjacent portion of the crosswalk 20A on the sidewalk 63a that is distant from the infrastructure radio wave sensor 10.

[0134] In the example of FIG. 17 , the detectable area 40 is not large enough to set a waiting area on the sidewalk 63b close to the infrastructure radio wave sensor 10. As described above, the entire near edges P1 and P4 of the crosswalk 20A are not included in the detectable area 40. In such a case, even if a waiting area is set on the sidewalk 63b, it is not possible to accurately detect pedestrians in the waiting area. For this reason, in the second embodiment, when the entire near edges P1 and P4 of the crosswalk 20A are outside the detectable area 40, a waiting area is not set on the sidewalk 63b adjacent to the near edge. In other words, the target area 30B does not include a waiting area on the sidewalk 63b close to the infrastructure radio wave sensor 10.

[0135] 17 , when one entire edge of a crosswalk 20A (an edge adjacent to the sidewalk) falls outside the detectable area 40, the setting support device 100 according to the second embodiment corresponds to a target area 30B that includes a first portion that is included in the detectable area 40 and a second portion that is not included in the detectable area 40, and supports setting a detection area in the infrastructure radio wave sensor 10.

[0136] 18 is a diagram showing an example of estimation of second definition points by the setting assistance device according to the second embodiment. In the example of FIG. 17, endpoints P2 and P3 are included in the detectable area 40, but endpoints P1 and P4 are not included in the detectable area 40. Therefore, the first determination unit 113 determines first definition points DP22 and DP32 corresponding to endpoints P2 and P3, but does not determine first definition points corresponding to endpoints P1 and P4. Therefore, the estimation unit 114 estimates second definition points EDP12 and EDP42 corresponding to endpoints P1 and P4.

[0137] As in the first embodiment, the creation unit 112 creates an approximation line AL21 of the detection trajectory R22m corresponding to the route from endpoint P1 to endpoint P2, and an approximation line AL22 of the detection trajectory R32m corresponding to the route from endpoint P3 to endpoint P4.

[0138] 18 , the estimation unit 114 uses the first condition regarding the positional relationship between the first definition point DP22 and the second definition point EDP12 to estimate the second definition point EDP12 corresponding to the endpoint P1. The estimation unit 114 uses the first condition regarding the positional relationship between the first definition point DP32 and the second definition point EDP42 to estimate the second definition point EDP42 corresponding to the endpoint P4.

[0139] The positional relationship between the first definition point DP22 and the second definition point EDP12 includes a direction (first direction) from the first definition point DP22 to the second definition point EDP12 and a distance (first distance) between the first definition point DP22 and the second definition point EDP12. The direction from the first definition point DP22 to the second definition point EDP12 is the direction from the first definition point DP22 along the approximation line AL21.

[0140] 17 , for example, a user actually measures the distance from endpoint P1 to endpoint P2 and inputs the measurement value into the setting support device 100. Referring to Fig. 18 , the input measurement value corresponds to the distance Dst22 between a first definition point DP22 corresponding to endpoint P2 and a second definition point EDP12 corresponding to endpoint P1. The estimation unit 114 estimates the second definition point EDP12 based on the distance Dst22 from the first definition point DP22.

[0141] 18 , the estimation unit 114 estimates the second definition point EDP12 based on two positional relationships: the distance Dst22 from the first definition point DP22 and the direction along the approximation line AL21 from the first definition point DP22. Specifically, the estimation unit 114 estimates, as the second definition point EDP12, a point that is the distance Dst22 from the first definition point DP22 along the approximation line AL21 from the first definition point DP22.

[0142] The positional relationship between the first definition point DP32 and the second definition point EDP42 includes a direction (first direction) from the first definition point DP32 to the second definition point EDP42 and a distance (first distance) between the first definition point DP32 and the second definition point EDP42. The direction from the first definition point DP32 to the second definition point EDP42 is the direction from the first definition point DP32 along the approximation line AL22.

[0143] 17 , for example, a user can actually measure the distance from endpoint P3 to endpoint P4 and input the measurement value into the setting support device 100. Referring to Fig. 18 , the input measurement value corresponds to the distance Dst32 between a first definition point DP32 corresponding to endpoint P3 and a second definition point EDP42 corresponding to endpoint P4. The estimation unit 114 estimates the second definition point EDP42 based on the distance Dst32 from the first definition point DP32.

[0144] 18 , the estimation unit 114 estimates the second definition point EDP42 based on two positional relationships: the distance Dst32 from the first definition point DP32 described above, and the direction along the approximation line AL22 from the first definition point DP32. Specifically, the estimation unit 114 estimates, as the second definition point EDP42, a point that is the distance Dst32 from the first definition point DP32 along the approximation line AL22 from the first definition point DP32.

[0145] FIG. 19 is a diagram showing an example of determining the detection area in the example of FIG. 18 . As shown in FIG. 19 , for example, the detection area 300C includes a zebra area 300C_1 corresponding to the crosswalk 20A and a pedestrian waiting area 300C_3 adjacent to the crosswalk 20A. The second determination unit 115 can determine the area surrounded by the second definition point EDP12, the first definition points DP22 and DP32, and the second definition point EDP42 as the zebra area 300C_1. In a specific example, the second determination unit 115 determines a polygon having the second definition point EDP12, the first definition points DP22 and DP32, and the second definition point EDP42 as its vertices as the zebra area 300C_1.

[0146] The second determination unit 115 can determine, as the waiting area 300C_3, an area obtained by extending the zebra area 300C_1 in the longitudinal direction. For example, the second determination unit 115 can determine, as the waiting area 300C_3, an area that is adjacent to an edge of the zebra area 300C_1 in the longitudinal direction that does not include the second definition points EDP12 and EDP42, i.e., an edge connecting the first definition points DP22 and DP32, and has a predetermined length in the longitudinal direction of the zebra area 300C_1. The determination of the waiting area 300C_3 is the same as the determination of the waiting area 300B_3 in the first embodiment.

[0147] 17 , the entire near edges P1 and P4 of the crosswalk 20A to the infrastructure radio wave sensor 10 are not included in the detectable area 40. In this case, the entire waiting area adjacent to the near edges P1 and P4 falls outside the detectable area 40. If the entire waiting area falls outside the detectable area 40, it is not possible to detect a pedestrian in this waiting area. For this reason, in the second embodiment, the second determination unit 115 does not determine a waiting area adjacent to the near edges P1 and P4 that fall outside the detectable area 40.

[0148] 19 , the near edges P1 and P4 of the crosswalk 20A described above correspond to the sides EDP12 and EDP42 of the zebra area 300C_1. The entire line segment EDP12 and EDP42 connecting the two second definition points EDP12 and EDP42 is outside the detectable area 400. The second determination unit 115 does not determine a waiting area adjacent to the sides EDP12 and EDP42 that include the second definition points EDP12 and EDP42.

[0149] In the second embodiment, the line segment EDP12, EDP42 connecting the second definition point EDP12 and the second definition point EDP42, which correspond to the near edges P1, P4 of the crosswalk 20A, is the crossing time prediction line. The infrastructure radio wave sensor 10, for which the detection area 300C is set, can predict the crossing time it will take for a pedestrian moving on the crosswalk 20A in the direction from the far edge toward the near edge (the direction from the first definition point DP22 toward the second definition point EDP12) to reach the crossing time prediction line EDP12, EDP42.

[0150] Other functions of the setting assistance device according to the second embodiment are the same as those of the setting assistance device 100 according to the first embodiment, and therefore description thereof will be omitted.

[0151] 20 is a diagram showing a modified example of estimation of the second definition point by the setting assistance device according to the second embodiment. The positional condition of the second definition point may include a second condition regarding a second positional relationship between the infrastructure radio wave sensor 10 and the second definition point, instead of or in addition to the first condition regarding the first positional relationship between the first definition point and the second definition point determined by the first determination unit 113.

[0152] In this modification, the estimation unit 114 estimates the second definition points EDP12 and EDP42 using the distances between the infrastructure radio wave sensor 10 and the second definition points EDP12 and EDP42. Specifically, the estimation unit 114 estimates the second definition points EDP12 and EDP42 using the distances Dst23 and Dst33 in the Y direction between the infrastructure radio wave sensor 10 and the second definition points EDP12 and EDP42.

[0153] 18 , for example, a user can actually measure the distance between the infrastructure radio wave sensor 10 and endpoint P1 in the direction of the projection central axis 31Y and the distance between the infrastructure radio wave sensor 10 and endpoint P4 in the direction of the projection central axis 31Y, and input the measured values ​​into the configuration assistance device 100. In the example of FIG. 18 , endpoint P1 is farther from the sidewalk 63a in the direction of the projection central axis 31Y than the infrastructure radio wave sensor 10, and endpoint P4 is closer to the sidewalk 63a in the direction of the projection central axis 31Y than the infrastructure radio wave sensor 10. Therefore, for example, the distance between the infrastructure radio wave sensor 10 and endpoint P1 in the direction of the projection central axis 31Y is a negative value, and the distance between the infrastructure radio wave sensor 10 and endpoint P4 in the direction of the projection central axis 31Y is a positive value.

[0154] 18, the projection center axis 31Y of the infrastructure radio wave sensor 10 is parallel to the side edges P3 and P4 of the crosswalk 20A. The projection center axis 31Y of the infrastructure radio wave sensor 10 is also parallel to the side edges P1 and P2 of the crosswalk 20A.

[0155] 20 , the measured value of the distance in the direction of the projection center axis 31Y between the infrastructure radio wave sensor 10 and the endpoint P1 corresponds to the distance Dst23 between the X axis of the sensor coordinate space and the second definition point EDP12 corresponding to the endpoint P1. The estimation unit 114 estimates the second definition point EDP12 based on the distance Dst23 from the X axis.

[0156] 20 , the estimation unit 114 estimates the second definition point EDP12 based on two positional relationships: the distance Dst23 from the X-axis and the direction along the approximation line AL21 from the first definition point DP22. Specifically, the estimation unit 114 estimates, as the second definition point EDP12, a point that is a distance Dst23 away from the X-axis in the direction along the approximation line AL21 from the first definition point DP22 (i.e., the direction of the X-axis).

[0157] The measured value of the distance in the direction of the projection center axis 31Y between the infrastructure radio wave sensor 10 and the endpoint P4 corresponds to the distance Dst33 between the X axis of the sensor coordinate space and the second definition point EDP42 corresponding to the endpoint P4. The estimation unit 114 estimates the second definition point EDP42 based on the distance Dst33 from the X axis.

[0158] 20 , the estimation unit 114 estimates the second definition point EDP42 based on two positional relationships: the distance Dst33 from the X-axis and the direction along the approximation line AL22 from the first definition point DP32. Specifically, the estimation unit 114 estimates, as the second definition point EDP42, a point that is a distance Dst33 away from the X-axis in the direction along the approximation line AL22 from the first definition point DP32 (i.e., the direction of the X-axis).

[0159] The estimation of the second definition points EDP12 and EDP42 in the second embodiment is not limited to the above. For example, the second definition points EDP12 and EDP42 may be estimated by at least one of the estimation methods of the first, second, and third modifications of the first embodiment.

[0160] [3. Other Modifications] In the first and second embodiments, it was described that a waiting area adjacent to an edge of the crosswalk 20 that is outside the detectable area 40 (the boundary with the sidewalk) is not determined, but this is not limiting. For example, a waiting area adjacent to an edge of the crosswalk 20 that is outside the detectable area 40 (the boundary with the sidewalk) may be determined. In this case, if a portion of the edge of the crosswalk 20 is outside the detectable area 40, a waiting area can be determined for that edge within the detectable area 40.

[0161] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present disclosure is defined by the claims, not the above-described embodiments, and includes meanings equivalent to the claims and all modifications within the scope thereof.

[0162] DESCRIPTION OF SYMBOLS 10 Infrastructure radio wave sensor (radio wave sensor) 11 Processor 12 Non-volatile memory 13 Memory 14 Transmitter / receiver 15 Transmitting circuit 15a Transmitting antenna 16 Receiving circuit 16a Receiving antenna 17 Detection circuit 18 Housing 19 Communication I / F 18a Transmitting / receiving surface 20, 20A Crosswalk 30, 30A, 30B Target area 30_1, 30A_1, 30B_1 Zebra area 30_2, 30_3, 30A_2, 30A_3, 30B_3 Waiting area 31O Point 31Y Projection center axis 31X Straight line 40 Detectable 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 Detectable area information 111 Acquisition unit 112 Creation unit 113 First determination unit 114 Estimation unit 115 Second determination unit 116 Setting unit 121 Setting information 201 Input device 202 Display device 300, 300B, 300C Detection area 300_1, 300B_1, 300C_1 Zebra area 300_2, 300_3, 300B_3, 300C_3 Waiting area 400 Detectable area P1, P2, P3, P4 End point P5, P6 Point P1m, P2m, P3m Detection point R1, R2, R3, R4 Route R1m, R2m, R3m, R4m, R22m, R32m Detection trajectory DP1, DP2, DP3, DP22, DP32 First defined point EDP4, EDP12, EDP42 Second defined point DP21, DP31 Third defined point AL3, AL4, AL21, AL22 Approximation line Dst1, Dst2, Dst3, Dst22, Dst32, Dst23, Dst33 Distance C1, C2 Circle TP1 Pedestrian ETP1 Point

Claims

1. A radio wave sensor that detects an object moving in a target area on a road, wherein when a detectable area in which an object can be detected includes a first portion of the target area and a second portion of the target area is not included in the detectable area, the radio wave sensor obtains a detection result of the object moving in the target area, and determines a virtual detection area for detecting the object on the road based on a first definition point that is determined based on the detection result and defines the first portion within the detectable area, and a second definition point that is estimated based on the detection result and defines the second portion outside the detectable area.

2. The radio wave sensor according to claim 1, wherein the second definition point is estimated based on a positional condition of the second definition point.

3. The radio wave sensor according to claim 2, wherein the positional condition of the second definition point includes a first condition regarding a first positional relationship between the first definition point and the second definition point.

4. The radio wave sensor according to claim 3, wherein the first positional relationship includes a first distance between the first defined point and the second defined point.

5. The radio wave sensor according to claim 4, wherein the first distance is a distance between a first definition point selected from a plurality of the first definition points and the second definition point.

6. The radio wave sensor according to claim 4, wherein the target area includes a first endpoint that is far from the radio wave sensor and a second endpoint that is close to the radio wave sensor, and the first distance is the distance between the first definition point and the second definition point that correspond to the second endpoint.

7. The radio wave sensor according to any one of claims 3 to 6, wherein the first positional relationship includes a first direction from the first defined point to the second defined point.

8. The radio wave sensor according to claim 7, wherein the first direction is a direction from a first definition point selected from a plurality of the first definition points to the second definition point.

9. The radio wave sensor according to claim 7, wherein the target area includes a first end point that is far from the radio wave sensor and a second end point that is close to the radio wave sensor, and the first direction is a direction from the first definition point corresponding to the first end point to the second definition point.

10. The radio wave sensor according to claim 2, wherein the positional conditions include a second condition regarding a second positional relationship between the radio wave sensor and the second definition point.

11. The radio wave sensor according to claim 10, wherein the second positional relationship includes a second distance between the radio wave sensor and the second definition point.

12. The radio wave sensor according to claim 10 or 11, wherein the second positional relationship includes a second direction from the radio wave sensor toward the second definition point.

13. The radio wave sensor according to claim 1 or claim 2, wherein the target area is a crosswalk, the crosswalk includes a first end point that is distant from the radio wave sensor and a second end point that is close to the radio wave sensor, the second definition point corresponds to the second end point, and a line that includes the second definition point included in the detection area is a crossing time prediction line for predicting the crossing time required for an object moving through the target area in a direction from the first end point to the second end point to complete crossing the target area.

14. A method for assisting in the configuration of a radio wave sensor, comprising the steps of: acquiring detection results from a radio wave sensor of an object moving in a target area on a road; when a detectable area in which an object can be detected includes a first portion of the target area and a second portion of the target area is not included in the detectable area, determining a first definition point that defines the first portion within the detectable area based on the acquired detection results; estimating a second definition point that defines the second portion outside the detectable area based on the acquired detection results; and determining a virtual detection area for the radio wave sensor to detect objects on a road based on the first definition point and the second definition point.

15. 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 an object moving in the target area by the radio wave sensor; when a detectable area in which an object can be detected includes a first portion of the target area but a second portion of the target area is not included in the detectable area, determining a definition point that defines the first portion within the detectable area based on the acquired detection results; estimating a second definition point that defines the second portion outside the detectable area based on the acquired detection results; and determining a virtual detection area for the radio wave sensor to detect objects on a road based on the determined first definition point and the estimated second definition point.

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