JP7582008B2 - Radio wave radar for infrastructure, data correction method for radio wave radar for infrastructure, correction data generating device, correction data generating method, and computer program - Google Patents

Description

This disclosure relates to an infrastructure radio radar, a data correction method for infrastructure radio radar, a correction data generation device, a correction data generation method, and a computer program.

Patent Document 1 discloses a road condition assessment device that detects the intensity and spectrum of reflected signals from vehicles using multiple radio radars installed on the lane, determines the position and speed of the vehicle in the lane direction using the intensity and spectrum of the reflected signals from the vehicle detected by the radio radar, determines that the reflected signals from the same traveling vehicle are from the same vehicle when at least two of the radio radars installed on each lane detect the reflected signals, calculates the maximum value of the amplitude of the reflected signals from the same traveling vehicle for each radio radar within a predetermined fixed period of time, and compares the maximum values to estimate the lane in which the vehicle is located and its position in the road width direction.

JP 2000-48296 A

In radio radars used for traffic monitoring on roads, etc. (hereinafter also referred to as "infrastructure radio radars"), it is desirable to constantly detect the position of a specific part of the vehicle body (for example, the center of the vehicle body). When a radio radar detects the position of a traveling vehicle, the positional relationship between the vehicle and the radio radar changes over time. For example, in a radio radar installed above the road, when the vehicle is close to the radio radar, the radio waves are reflected mainly by the roof part of the vehicle body, and when the vehicle is far from the radio radar, the radio waves are reflected mainly by the front part (or tail part) of the vehicle body. In this way, when the positional relationship between the vehicle and the radio radar changes, the reflecting surface of the vehicle body for the radio waves changes, making it difficult to detect the position of the same part of the vehicle body.

An infrastructure radio wave radar according to one embodiment of the present disclosure includes a receiving antenna configured to receive reflected waves by a vehicle of radio waves irradiated to a target area, an identification unit configured to identify a first position of the vehicle based on the reflected waves received by the receiving antenna, and a correction unit configured to acquire a correction amount corresponding to the first position identified by the identification unit according to correction data indicating a correspondence between the first position of the vehicle and the correction amount, and to determine a second position by correcting the first position using the acquired correction amount.

A data correction method for an infrastructure radio wave radar according to one aspect of the present disclosure includes the steps of: identifying a first position of a vehicle based on a reflected wave by the vehicle of radio waves irradiated by the infrastructure radio wave radar to a target area; acquiring a correction amount corresponding to the first position according to correction data indicating a correspondence relationship between the first position of the vehicle and the correction amount; and determining a second position by correcting the first position using the acquired correction amount.

A correction data generating device according to one aspect of the present disclosure includes a first identification unit configured to identify a first position in a predetermined coordinate space, which is the position of a vehicle detected by an infrastructure radio radar, a second identification unit configured to identify a reference position in the coordinate space, which is the position of a reference part of the vehicle, and a generation unit configured to generate correction data in which a correction amount, which is the difference between the first position and the reference position, and the first position are associated with each other.

A correction data generation method according to one aspect of the present disclosure includes the steps of: identifying a first position in a predetermined coordinate space, which is the position of a vehicle detected by an infrastructure radio wave radar; identifying a reference position in the coordinate space, which is the position of a reference part of the vehicle; and generating correction data in which a correction amount, which is the difference between the first position and the reference position, and the first position are associated with each other.

A computer program according to one aspect of the present disclosure is a computer program for generating correction data for correcting the position of a vehicle detected by an infrastructure radio radar, and causes the computer to execute the steps of identifying a first position in a predetermined coordinate space, which is the position of the vehicle detected by the infrastructure radio radar, identifying a reference position in the coordinate space, which is the position of a reference part of the vehicle, and generating correction data in which a correction amount, which is the difference between the first position and the reference position, and the first position are associated with each other.

The present disclosure can be realized not only as an infrastructure radio radar having the above-mentioned characteristic configuration, or as a data correction method for infrastructure radio radar having characteristic processing steps, but also as a computer program that causes a computer to execute the above-mentioned method, or as a vehicle position detection system including an infrastructure radio radar. The present disclosure can be realized not only as a correction data generation device having the above-mentioned characteristic configuration, a correction data generation method having characteristic processing steps, or a computer program that causes a computer to execute characteristic steps, but also as a correction data generation system including a correction data generation device.

According to the present disclosure, it is possible to stabilize the detection accuracy of the vehicle position by the infrastructure radio radar, regardless of the positional relationship between the infrastructure radio radar and the vehicle.

FIG. 2 is a diagram illustrating an example of use of the radar according to the first embodiment. 1 is a perspective view showing an example of an external configuration of a radar according to a first embodiment. FIG. 1 is a block diagram showing an example of an internal configuration of a radar according to a first embodiment. FIG. FIG. 2 is a functional block diagram showing an example of functions of a radar according to the first embodiment. FIG. 1 is a diagram showing an example of a distribution of reflection points on a vehicle located close to a radar. FIG. 1 is a diagram showing an example of a distribution of reflection points on a vehicle located at a distance from a radar. 4 is a graph showing an example of the relationship between the relative distance between a vehicle and a radar and the signal strength of a reflected wave. 10 is a graph showing an example of a relationship between a relative angle between a vehicle and a radar and a signal strength of a reflected wave. 5 is a diagram showing an example of a configuration of correction data according to the first embodiment; FIG. 11 is a graph showing an example of Y correction data. 11 is a graph showing an example of X correction data. 6A to 6C are diagrams for explaining a specific example of correction of a first position by a correction unit according to the first embodiment. 4 is a flowchart showing an example of an operation procedure of the radar according to the first embodiment. 1 is a block diagram showing an example of a configuration of a correction data generating device according to a first embodiment. FIG. 2 is a functional block diagram showing an example of functions of the correction data generating device according to the first embodiment. FIG. 4 is a diagram for explaining a first position and a reference position. 5 is a flowchart showing an example of an operation procedure of the correction data generating device according to the first embodiment. FIG. 11 is a diagram showing an example of a configuration of correction data according to the second embodiment;

Overview of the embodiments of the present disclosure
Below, an overview of the embodiments of the present disclosure will be listed and described.

(1) The infrastructure radio wave radar according to this embodiment includes a receiving antenna configured to receive reflected waves by a vehicle of radio waves irradiated to a target area, an identification unit configured to identify a first position of the vehicle based on the reflected waves received by the receiving antenna, and a correction unit configured to acquire a correction amount corresponding to the first position identified by the identification unit according to correction data indicating a correspondence between the first position of the vehicle and the correction amount, and to determine a second position by correcting the first position by the acquired correction amount. This allows the first position to be corrected by a correction amount according to the first position, so that the detection accuracy of the vehicle position by the infrastructure radio wave radar can be stabilized regardless of the positional relationship between the infrastructure radio wave radar and the vehicle.

(2) The first position includes a lane length component and a lane width component, the correction data includes first correction data used to correct the lane length component and second correction data used to correct the lane width component, and the correction unit may determine the lane length component of the second position according to the first correction data and determine the lane width component of the second position according to the second correction data. This makes it possible to stabilize the detection accuracy of the vehicle position by the infrastructure radio radar in a space including the lane length direction and the lane width direction.

(3) The first correction data may indicate a correspondence relationship between the lane length component of the first position and a correction amount of the lane length component, and the second correction data may indicate a correspondence relationship between the lane length component of the first position and a correction amount of the lane width component. When the relative position in the lane length direction between the infrastructure radio wave radar and the vehicle changes, the reflection surface of the radio wave on the vehicle body changes. With the above configuration, the lane length component and the lane width component of the first position can be corrected according to the relative position in the lane length direction between the infrastructure radio wave radar and the vehicle, and the detection accuracy of the vehicle position by the infrastructure radio wave radar can be stabilized.

(4) The first position may further include a height direction component, the correction data may further include third correction data used to correct the height direction component, and the correction unit may determine the height direction component of the second position according to the third correction data. This makes it possible to stabilize the detection accuracy of the vehicle position by the infrastructure radio radar in a space including the lane length direction, lane width direction, and height direction.

(5) The third correction data may indicate a correspondence relationship between the lane length component of the first position and the correction amount of the height direction component. When the relative position in the lane length direction between the infrastructure radio wave radar and the vehicle changes, the radio wave reflection surface on the vehicle body changes. With the above configuration, the height direction component of the first position can be corrected according to the relative position in the lane length direction between the infrastructure radio wave radar and the vehicle, and the detection accuracy of the vehicle position by the infrastructure radio wave radar can be stabilized.

(6) The correction data includes first vehicle type correction data used for a first vehicle type whose vehicle size is defined in a predetermined first category, and second vehicle type correction data used for a second vehicle type whose vehicle size is defined in a second category different from the first category, and the infrastructure radio wave radar further includes a vehicle type identification unit that identifies whether the vehicle belongs to the first vehicle type or the second vehicle type based on the reflected wave received by the receiving antenna, and the correction unit may obtain a correction amount corresponding to the first position according to the first vehicle type correction data when the vehicle is identified as belonging to the first vehicle type, and obtain a correction amount corresponding to the first position according to the second vehicle type correction data when the vehicle is identified as belonging to the second vehicle type. The error of the detected position by the infrastructure radio wave radar changes depending on the vehicle size. With the above configuration, the detected position by the infrastructure radio wave radar can be corrected with a correction amount according to the vehicle size.

(7) The identification unit may obtain a representative value of multiple reflection points detected from reflected waves from the same vehicle, and set the representative value to the first position. This makes it possible to stabilize the first position detected by the infrastructure radio radar. By correcting such a first position, it is possible to stabilize the detection accuracy by the infrastructure radio radar.

(8) The representative value may be the center of gravity of the multiple reflection points. This makes it possible to suppress sudden changes in the first position in response to changes in the positional relationship between the infrastructure radio radar and the vehicle in the lane length direction. This makes it possible to stabilize the detection accuracy of the infrastructure radio radar.

(9) The data correction method for the infrastructure radio radar according to this embodiment includes the steps of: identifying a first position of the vehicle based on the reflected waves by the vehicle of the radio waves irradiated by the infrastructure radio radar to a target area; and acquiring a correction amount corresponding to the first position according to correction data indicating the correspondence between the first position of the vehicle and the correction amount, and determining a second position by correcting the first position by the acquired correction amount. This allows the first position to be corrected by the correction amount according to the first position, so that the detection accuracy of the vehicle position by the infrastructure radio radar can be stabilized regardless of the positional relationship between the infrastructure radio radar and the vehicle.

(10) The correction data generation device according to this embodiment includes a first identification unit configured to identify a first position in a predetermined coordinate space, which is the position of the vehicle detected by an infrastructure radio radar, a second identification unit configured to identify a reference position in the coordinate space, which is the position of a reference part of the vehicle, and a generation unit configured to generate correction data in which a correction amount, which is the difference between the first position and the reference position, and the first position are associated with each other. This makes it possible to generate correction data for correcting the position detected by the infrastructure radio radar according to the relative positions of the infrastructure radio radar and the vehicle.

(11) The first position may include a lane length component and a lane width component, and the correction data may include first correction data in which a correction amount of the lane length component of the first position and the first position are associated with each other, and second correction data in which a correction amount of the lane width component of the first position and the first position are associated with each other. This makes it possible to generate correction data for correcting the position of a vehicle detected by an infrastructure radio radar in a space including the lane length direction and the lane width direction.

(12) The first correction data may indicate a correspondence relationship between the lane length component of the first position and a correction amount of the lane length component, and the second correction data may indicate a correspondence relationship between the lane length component of the first position and a correction amount of the lane width component. This makes it possible to generate correction data for correcting each of the lane length component and the lane width component of the first position according to the relative positions of the infrastructure radio radar and the vehicle in the lane length direction.

(13) The first position may further include a height component, and the correction data may include third correction data in which the correction amount of the height component of the first position and the first position are associated with each other. This makes it possible to generate correction data for correcting the position of a vehicle detected by an infrastructure radio radar in a space including a lane length direction, a lane width direction, and a height direction.

(14) The third correction data may indicate a correspondence relationship between the lane length component of the first position and the correction amount of the height component. This makes it possible to generate correction data for correcting the height component of the first position depending on the relative position in the lane length direction between the infrastructure radio radar and the vehicle.

(15) The first identification unit identifies the first position of a first vehicle belonging to a first vehicle type whose vehicle size is defined in a predetermined first division, the second identification unit identifies the reference position of the first vehicle, the generation unit generates first vehicle type correction data that is correction data for the first vehicle type, the first vehicle type correction data being data in which a correction amount that is a difference between the first position of the first vehicle and the reference position of the first vehicle and the first position of the first vehicle are associated with each other, the first identification unit identifies the first position of a second vehicle belonging to a second vehicle type whose vehicle size is defined in a second division different from the first division, the second identification unit identifies the reference position of the second vehicle, the generation unit generates second vehicle type correction data that is correction data for the second vehicle type, the second vehicle type correction data being data in which a correction amount that is a difference between the first position of the second vehicle and the reference position of the second vehicle and the first position of the second vehicle are associated with each other. This makes it possible to generate first vehicle type correction data and second vehicle type correction data to correct the position detected by the infrastructure radio radar according to the vehicle size.

(16) The first position may be a representative value of a plurality of reflection points detected by the infrastructure radio radar from the same vehicle. This makes it possible to stabilize the first position, and to generate correction data for accurately correcting the detection position of the infrastructure radio radar using such a first position.

(17) The representative value may be the center of gravity of the multiple reflection points. This makes it possible to suppress sudden changes in the first position in response to changes in the positional relationship between the infrastructure radio radar and the vehicle in the lane length direction. Using such a first position, correction data can be generated for accurately correcting the detection position of the infrastructure radio radar.

(18) The first identification unit may identify the first position calculated by a simulator of the infrastructure radio radar. This makes it possible to generate correction data without actually operating the infrastructure radio radar.

(19) The correction data generation method according to this embodiment includes the steps of: identifying a first position in a predetermined coordinate space, which is the position of the vehicle detected by an infrastructure radio radar; identifying a reference position in the coordinate space, which is the position of a reference part of the vehicle; and generating correction data in which a correction amount, which is the difference between the first position and the reference position, and the first position correspond to each other. This makes it possible to generate correction data for correcting the position detected by the infrastructure radio radar according to the relative positions of the infrastructure radio radar and the vehicle.

(20) A computer program according to this embodiment is a computer program for generating correction data for correcting a position of a vehicle detected by an infrastructure radio radar, and causes the computer to execute the steps of identifying a first position in a predetermined coordinate space, which is the position of the vehicle detected by the infrastructure radio radar, identifying a reference position in the coordinate space, which is the position of a reference part of the vehicle, and generating correction data in which a correction amount, which is the difference between the first position and the reference position, and the first position are associated with each other. This makes it possible to generate correction data for correcting the position detected by the infrastructure radio radar according to the relative positions of the infrastructure radio radar and the vehicle.

<Details of the embodiment of the present disclosure>
Hereinafter, the details of the embodiments of the present invention will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any desired manner.

[1. First embodiment]
[1-1. Radar]
FIG. 1 is a diagram showing an example of use of a radar according to the first embodiment. The radar 100 according to this embodiment is a radio wave radar for traffic monitoring (radio wave radar for infrastructure). The radar 100 is attached to an arm 200 (see FIG. 2) or the like provided at an intersection or a road. The radar 100 is a millimeter wave radar and a radio wave sensor. The radar 100 irradiates a target area 300 on a road with radio waves (millimeter waves) and detects an object (e.g., a vehicle V) within the target area 300 by receiving the reflected waves. More specifically, the radar 100 can detect the distance to the vehicle V traveling on the road, the speed of the vehicle V, and the horizontal angle of the position where the vehicle V is located relative to the radar's radio wave irradiation axis.

The radar 100 is installed so that the direction of the radio wave irradiation axis (indicated by the dashed line in FIG. 1; hereafter referred to as the "reference direction") faces the target area 300. If the reference direction does not face the target area 300 correctly, the radar 100 cannot accurately detect objects within the target area 300. For this reason, the angle of the radar 100 is adjusted so that the reference direction faces the target area 300.

In the following description, the lane length direction in the target area 300 is designated as Y, the lane width direction as X, and the height direction as Z. The origin is a point on the road surface vertically below the radar 100. The coordinate system defined by X, Y, and Z is used by the radar 100.

Figure 2 is a perspective view showing an example of the external configuration of the radar 100 according to the first embodiment. As shown in Figure 2, the radar 100 has a transmitting/receiving surface 101 for transmitting and receiving millimeter waves. The reference direction is the normal direction of the transmitting/receiving surface 101. The radar 100 incorporates at least one transmitting antenna and multiple (e.g., two) receiving antennas. The radar 100 transmits modulated waves, which are millimeter waves, from the transmitting antenna through the transmitting/receiving surface 101. The modulated waves hit an object and are reflected, and the receiving antenna receives the reflected waves. The radar 100 performs signal processing on the transmitted wave signal and the received wave signal using a signal processing circuit (not shown) to detect the distance to the object, the angle at which the object is present (hereinafter referred to as the "position of the object"), and the speed of the object.

The radar 100 is configured to be able to adjust the installation angle. The radar 100 includes a radar body 102, a depression angle adjustment unit 103, a horizontal angle adjustment unit 104, and a roll angle adjustment unit 105. The radar body 102 is formed in a box shape, and the depression angle adjustment unit 103 is attached to the side of the radar body 102. The radar body 102 can be rotated around a horizontal axis by the depression angle adjustment unit 103, thereby adjusting the depression angle of the radar body 102. The radar body 102 connected to the roll angle adjustment unit 105 via the depression angle adjustment unit 103 can be rotated left and right toward the transmission and reception surface 101 by the roll angle adjustment unit 105, thereby adjusting the roll angle of the radar body 102. The horizontal angle adjustment unit 104 is fixed to a pole on which the radar body 102 is to be installed. The radar body 102, which is connected to the horizontal angle adjustment unit 104 via the depression angle adjustment unit 103 and the roll angle adjustment unit 105, can be rotated around a vertical axis by the horizontal angle adjustment unit 104, thereby adjusting the horizontal angle of the radar body 102.

The radar 100 detects a vehicle V for each lane. The radar 100 identifies the coordinates of the detected vehicle V in a set coordinate space.

[1-2. Radar Configuration]
3 is a block diagram showing an example of the internal configuration of the radar according to the first embodiment. The radar 100 includes a processor 111, a non-volatile memory 112, a volatile memory 113, a transmission circuit 114, a reception circuit 115, and a communication interface (communication I/F) 116.

The volatile memory 113 is a semiconductor memory such as a static random access memory (SRAM) or a dynamic random access memory (DRAM). The non-volatile memory 112 is a flash memory, a hard disk, a read only memory (ROM), etc. The non-volatile memory 112 stores a data correction program 117, which is a computer program, and correction data 400 used to execute the data correction program 117. The radar 100 is configured with a computer, and each function of the radar 100 is performed by the processor 111 executing the data correction program 117, which is a computer program stored in the storage device of the computer. The data correction program 117 can be stored in a recording medium such as a flash memory, a ROM, or a CD-ROM. The processor 111 executes the data correction program 117 and corrects the detected position (first position) of the vehicle V as described below.

The processor 111 is, for example, a CPU (Central Processing Unit). However, the processor 111 is not limited to a CPU. The processor 111 may be a GPU (Graphics Processing Unit). The processor 111 may be, for example, an ASIC (Application Specific Integrated Circuit) or a programmable logic device such as a gate array or an FPGA (Field Programmable Gate Array). In this case, the ASIC or the programmable logic device is configured to be capable of executing processing similar to that of the data correction program 117.

The transmission circuit 114 includes a transmission antenna 114a. The transmission circuit 114 generates a modulated wave and transmits the generated modulated wave from the transmission antenna 114a. The transmitted modulated wave hits an object (e.g., a vehicle V) and is reflected.

The receiving circuit 115 includes receiving antennas 115a and 115b. The receiving antennas 115a and 115b receive reflected waves from the vehicle V. The receiving circuit 115 performs signal processing on the received reflected waves. The reflected wave data generated by the signal processing is provided to the processor 111. The processor 111 analyzes the reflected wave data and detects the position and speed of the vehicle V.

The communication I/F 116 can communicate with an external device via wired or wireless communication. The communication I/F 116 can transmit information about the vehicle V detected by the radar 100 to an external device. For example, the communication I/F 116 is a wireless communication interface for DSRC (Dedicated Short Range Communications). The communication I/F 116 transmits position information and speed information of the vehicle V detected by road-to-vehicle communication to the vehicle V traveling in the target area 300.

The correction data 400 is generated by a correction data generating device 700 (see FIG. 11 ), which will be described later. For example, the correction data generating device 700 transmits the correction data 400, and the communication I/F 116 receives the correction data 400 and writes it to the non-volatile memory 112. The correction data generating device 700 may write the correction data 400 to a portable recording medium 710, and the recording medium 710 may be attached to a reading device (not shown) provided in the radar 100, and the correction data may be transferred from the recording medium 710 to the non-volatile memory 112.

[1-3. Radar Functions]
4 is a functional block diagram showing an example of functions of the radar 100 according to the first embodiment. When the processor 111 executes the data correction program 117, the radar 100 exhibits the functions of an input unit 121, a grouping unit 122, an identification unit 123, a vehicle type identification unit 124, a selection unit 125, a correction unit 126, and an output unit 127.

The input unit 121 receives the reflected wave data generated by the receiving circuit 115.

Figures 5A and 5B are diagrams for explaining the change in reflection points depending on the vehicle's position. Figure 5A shows an example of the distribution of reflection points on a vehicle V located close to the radar 100, and Figure 5B shows an example of the distribution of reflection points on a vehicle V located far away from the radar 100.

As shown in FIG. 5A, when a vehicle V is present in a position close to the radar 100, the radio waves emitted from the radar 100 are mainly reflected by the upper surface of the vehicle V, i.e., the roof, bonnet, upper surface of the trunk lid, etc. Therefore, the reflection point 500 occurs on the part of the upper surface of the vehicle V that is close to the radar 100 (the bonnet and roof if the front part of the vehicle V faces the radar 100; the upper surface of the trunk lid and roof if the rear part of the vehicle V faces the radar 100).

As shown in FIG. 5B, when a vehicle V is present at a position away from the radar 100, the radio waves emitted from the radar 100 are mainly reflected at the end face of the vehicle V, i.e., the front or rear. Therefore, the reflection point 500 occurs at the end face of the vehicle body on the side closer to the radar 100 (the front part if the front part of the vehicle V faces the radar 100; the rear part if the rear part of the vehicle V faces the radar 100).

Refer to FIG. 4 again. The grouping unit 122 extracts reflection points, which are peak points included in the reflected wave. FIGS. 6A and 6B are graphs for explaining the extraction of reflection points. FIG. 6A shows an example of the relationship between the relative distance between the vehicle V and the radar 100 and the signal strength of the reflected wave, and FIG. 6B is a graph showing an example of the relationship between the relative angle between the vehicle V and the radar 100 and the signal strength of the reflected wave. The grouping unit 122 extracts a peak point 511 from the waveform 510 of the reflected wave for the distance, and extracts a peak point 521 from the waveform 520 of the reflected wave for the angle. The grouping unit 122 determines the reflection point 500 by associating the peak point 511 with the peak point 521. The grouping unit 122 converts the coordinate value of the reflection point 500 from the polar coordinate display to the XY coordinate display.

The radio waves emitted from the radar 100 may be reflected simultaneously by multiple vehicles V. The grouping unit 122 groups the reflection points 500 on the same vehicle V.

The identification unit 123 identifies a first position of the vehicle V based on the reflected waves received by the receiving antennas 115a and 115b. The first position is expressed as a coordinate value in an XY coordinate system. Specifically, the identification unit 123 determines a representative value of the reflection points 500 belonging to the same group, and sets the determined representative value as the first position. For example, the representative value is the center of gravity. However, the first position may be a representative value other than the center of gravity of the multiple reflection points 500. For example, the representative value may be the average value of the reflection points 500, or the median value of the reflection points 500.

In this embodiment, the vehicles V are classified into three vehicle types: compact cars, medium-sized cars, and large cars. A compact car is a vehicle V that satisfies both of the following conditions (1-1) and (1-2).
(1-1) The vehicle length is L1 (e.g., 3.4 m) or less.
(1-2) The vehicle width is W1 (e.g., 1.48 m) or less.

A medium-sized vehicle is, for example, a vehicle that does not satisfy either of the conditions (1-1) and (1-2) but satisfies the conditions (2-1) and (2-2).
(2-1) The vehicle length is L2 (e.g., 5 m) or less.
(2-2) The vehicle width is W3 (e.g., 2 m) or less.

A large vehicle is, for example, a vehicle that does not satisfy either of conditions (1-1) and (1-2) and does not satisfy either of conditions (2-1) and (2-2). In other words, a large vehicle is a vehicle whose length is greater than L2 or whose width is greater than W2.

The vehicle type identification unit 124 identifies the vehicle type to which the vehicle V belongs based on the reflected waves received by the receiving antennas 115a and 115b. Specifically, the vehicle type identification unit 124 identifies whether the vehicle V corresponding to the group belongs to a small vehicle, a medium vehicle, or a large vehicle based on the Y-direction distance between the two reflection points 500 that are most distant in the Y direction and the X-direction distance between the two reflection points 500 that are most distant in the X direction among the reflection points 500 that belong to the same group.

The correction data 400 includes correction data 410 for small vehicles, correction data 420 for medium vehicles, and correction data 430 for large vehicles. The correction data 410 for small vehicles is used to correct the position of a small vehicle, the correction data 420 for medium vehicles is used to correct the position of a medium vehicle, and the correction data 430 for large vehicles is used to correct the position of a large vehicle. If it is assumed that the first vehicle type is a small vehicle, the second vehicle type is a medium or large vehicle. In this case, the correction data 410 for small vehicles corresponds to the correction data for the first vehicle type, and the correction data 420 for medium vehicles or the correction data 430 for large vehicles corresponds to the correction data for the second vehicle type. If it is assumed that the first vehicle type is a medium vehicle, the second vehicle type is a small or large vehicle. In this case, the correction data for medium-sized vehicles 420 corresponds to the correction data for the first vehicle type, and the correction data for small vehicles 410 or the correction data for large vehicles 430 corresponds to the correction data for the second vehicle type. If it is assumed that the first vehicle type is a large vehicle, the second vehicle type is a small or medium-sized vehicle. In this case, the correction data for large vehicles 430 corresponds to the correction data for the first vehicle type, and the correction data for small vehicles 410 or the correction data for medium-sized vehicles 420 corresponds to the correction data for the second vehicle type.

The selection unit 125 selects data corresponding to the vehicle type of the vehicle V identified by the vehicle type identification unit 124 from the small vehicle correction data 410, the medium vehicle correction data 420, and the large vehicle correction data 430. In other words, if the vehicle type identification unit 124 identifies the vehicle type of the vehicle V as a small vehicle, the selection unit 125 selects the small vehicle correction data 410. If the vehicle type identification unit 124 identifies the vehicle type of the vehicle V as a medium vehicle, the selection unit 125 selects the medium vehicle correction data 420. If the vehicle type identification unit 124 identifies the vehicle type of the vehicle V as a large vehicle, the selection unit 125 selects the large vehicle correction data 430.

Figure 7 is a diagram showing an example of the configuration of correction data according to the first embodiment. Small vehicle correction data 410 includes Y correction data 411 and X correction data 412. Medium vehicle correction data 420 includes Y correction data 421 and X correction data 422. Large vehicle correction data 430 includes Y correction data 431 and X correction data 432. The Y correction data 411, 421, and 431 are used to correct the Y component of the first position, and the X correction data 412, 422, and 432 are used to correct the X component of the first position.

Figure 8A is a graph showing an example of Y correction data, and Figure 8B is a graph showing an example of X correction data. Figures 8A and 8B show X correction data 411 and Y correction data 412 of small vehicle correction data 410, but the same is true for X correction data 421 and Y correction data 422 of medium vehicle correction data 420, and X correction data 431 and Y correction data 432 of large vehicle correction data 430. Correction data 400 shows the correspondence between the first position of vehicle V and the correction amount. Y correction data 411 shows the correspondence between the Y component of the first position and the correction amount AY in the Y direction. X correction data 412 shows the correspondence between the Y component of the first position and the correction amount AX in the X direction.

The correction amount AY in the Y direction changes according to the Y component of the first position of the vehicle V. The correction amount AY corresponding to the Y component of the first position of the vehicle V is specified by the Y correction data 411. The Y correction data 411 is, for example, a function with the Y component of the first position and the correction amount AY as variables. The Y correction data 411 may be a lookup table in which the Y value of the first position and the correction amount AY are associated. The correction amount AX in the X direction changes according to the Y component of the first position of the vehicle V. The correction amount AX corresponding to the Y component of the first position of the vehicle V is specified by the X correction data 412. The X correction data 412 is, for example, a function with the Y component of the first position and the correction amount AX as variables. The X correction data 412 may be a lookup table in which the Y value of the first position and the correction amount AX are associated.

Refer to FIG. 4 again. The correction unit 126 acquires the correction amounts AY and AX corresponding to the first position identified by the identification unit 123 according to the correction data 400, and determines a second position obtained by correcting the first position using the acquired correction amounts AY and AX. Specifically, the correction unit 126 acquires the correction amount AY corresponding to the Y component of the first position according to the Y correction data included in the correction data selected by the selection unit 125. The correction unit 126 acquires the correction amount AX corresponding to the Y component of the first position according to the X correction data included in the correction data selected by the selection unit 125. The correction unit 126 corrects the Y component of the first position using the acquired correction amount AY, and determines the Y component of the second position. The correction unit 126 corrects the X component of the first position using the acquired correction amount AX, and determines the X component of the second position.

FIG. 9 is a diagram for explaining a specific example of the correction of the first position by the correction unit according to the first embodiment. As described above, the first position 530 is a representative value of the multiple reflection points 500. The correction unit 126 adds the correction amount AY in the Y direction to the Y component of the first position 530 to determine the Y component of the second position 600. The correction unit 126 adds the correction amount AX in the X direction to the X component of the first position 530 to determine the X component of the second position 600. The second position 600 is, for example, the XY coordinate value of a reference point of the vehicle V. The reference point may be, for example, the center of gravity of the vehicle body, or another specific point on the vehicle body.

Referring again to FIG. 4. The output unit 127 outputs position information (hereinafter also referred to as "detected position data") indicating the second position 600 determined by the correction unit 126. For example, the output unit 127 transmits the detected position data to an external device. In a specific example, the output unit 127 wirelessly transmits the detected position data to the vehicle V traveling in the target area 300 by road-to-vehicle communication. The detected position data is received by a communication device mounted on the vehicle V. The detected position data is used for automatic driving of the vehicle V. For example, the vehicle V automatically changes lanes according to the detected positions of surrounding vehicles notified by the radar 100.

[1-4. Radar Operation]
10 is a flowchart showing an example of an operation procedure of the radar 100 according to the first embodiment. When the processor 111 starts the data correction program 117, the radar 100 executes the process described below.

The transmitting circuit 114 generates a modulated wave and transmits the generated modulated wave from the transmitting antenna 114a. The transmitted modulated wave hits the vehicle V, and the reflected wave from the vehicle V is received by the receiving antennas 115a and 115b. The receiving circuit 115 processes the reflected wave signal and generates reflected wave data. The processor 111 reads the reflected wave data (step S101).

The processor 111 analyzes the reflected wave data and detects the reflection points 500 (step S102). The processor 111 groups the reflection points 500 on the same vehicle V (step S103).

The processor 111 estimates the size of the vehicle V based on the grouped reflection points 500 and identifies the vehicle type (compact, medium, or large) of the vehicle V (step S104). The processor 111 selects data corresponding to the identified vehicle type from among the small vehicle correction data 410, the medium vehicle correction data 420, and the large vehicle correction data 430 stored in the non-volatile memory 112 (step S105).

The processor 111 determines a representative value 530 of the grouped reflection points 500, and sets the representative value 530 to the first position of the vehicle V (step S106). The processor 111 corrects the detected first position according to the correction data selected in step S105, and determines the second position (step S107). The processor 111 transmits position information indicating the second position to an external device (step S108). The radar 100 repeats the above operations.

[1-5. Configuration of the correction data generating device]
Next, a description will be given of a correction data generating device that generates the above-mentioned correction data 400. Fig. 11 is a block diagram showing an example of the configuration of the correction data generating device according to the first embodiment.

The correction data generating device 700 is configured by an information terminal such as a computer or a tablet. The correction data generating device 700 includes a processor 701, a non-volatile memory 702, a volatile memory 703, an input device 704, a display device 705, a writing device 706, and a communication I/F 707.

The volatile memory 703 is, for example, a semiconductor memory such as an SRAM or a DRAM. The non-volatile memory 702 is, for example, a flash memory, a hard disk, a ROM, or the like. The non-volatile memory 702 stores a correction data generation program 708, which is a computer program, and data used to execute the correction data generation program 708. The correction data generation device 700 is configured with a computer, and each function of the correction data generation device 700 is exerted by the processor 701 executing the correction data generation program 708, which is a computer program stored in a storage device of the computer. The correction data generation program 708 can be stored in a recording medium such as a flash memory, a ROM, or a CD-ROM. The processor 701 executes the correction data generation program 708 and generates the correction data 400 as described below.

The processor 701 is, for example, a CPU. However, the processor 701 is not limited to a CPU. The processor 701 may be a GPU. The processor 701 may be, for example, an ASIC, or a programmable logic device such as a gate array or FPGA. In this case, the ASIC or programmable logic device is configured to be capable of executing processing similar to the correction data generation program 708.

The input device 704 may be a keyboard and a pointing device such as a mouse. The input device 704 is used to input information to the correction data generating device 700. The display device 705 includes, for example, a liquid crystal panel or an OEL (organic electroluminescence) panel. The display device 705 can display text or graphic information.

The portable recording medium 710 can be loaded into the writing device 706. The writing device 706 can write data to the loaded recording medium 710. The writing device 706 can write the generated correction data 400 to the recording medium 710 in response to a command from the processor 701.

The communication I/F 707 can communicate with an external device via wired or wireless communication. The communication I/F 407 can communicate with, for example, the radar 100. The communication I/F 407 can transmit the generated correction data 400 to the radar 100 in response to a command from the processor 701.

[1-6. Functions of the correction data generating device]
12 is a functional block diagram showing an example of functions of the correction data generating device 700 according to the first embodiment. When the processor 701 executes the correction data generating program 708, the correction data generating device 700 exhibits the functions of a first identification unit 711, a second identification unit 712, a vehicle model designation unit 713, a generation unit 714, and an output unit 715.

The first identification unit 711 identifies a first position 530 in the XY coordinate space, which is the position of the vehicle V detected by the radar 100. For example, the correction data generation device 700 can receive data indicating the detected position of the vehicle V before correction, i.e., the first position (hereinafter referred to as "first position data") from the radar 100 or another external device, or read the first position data stored in the recording medium 710, and identify the first position from the acquired first position data. For example, the radar 100 intermittently detects the first position of the vehicle V in the target area 300 at predetermined intervals. The first position data is time-series data indicating the transition of the first position of the vehicle V in the XY coordinates.

The second identification unit 712 identifies a reference position in the XY coordinate space, which is the position of the reference part of the vehicle V. For example, the correction data generation device 700 can receive data indicating the reference position of the vehicle V (hereinafter referred to as "reference position data") from an on-board device of the vehicle V or another external device, or read out the reference position data stored in the recording medium 710, and identify the reference position from the acquired reference position data. For example, while the first position is being intermittently detected by the radar 100 as described above, the position of the reference part of the vehicle V (reference position) is intermittently detected at predetermined intervals by a detection means different from the radar 100. The reference position data is time-series data indicating the transition of the reference position in the XY coordinates of the vehicle V.

A detection means different from the radar 100 is, for example, RTK (Real Time Kinematic) measurement. In RTK measurement, the position of the vehicle V is measured by a GNSS (Global Navigation Satellite System) receiver mounted on the vehicle V, and the measured position is corrected based on the position measured by the GNSS receiver at the reference station, thereby making it possible to accurately detect the position of the vehicle V (or the GNSS receiver mounted on the vehicle V). The reference part of the vehicle V is the mounting part of the GNSS receiver on the vehicle body.

The vehicle type designation unit 713 designates the vehicle type (compact, medium, or large vehicle) for which correction data is to be generated. For example, the correction data generation device 700 displays a screen on the display device 705 requesting input of the target vehicle type, and accepts vehicle type information input by the user via the input device 704. In another example, the radar 100 estimates the size (vehicle length, vehicle width) of the detected vehicle V based on the grouped reflection points 500, and identifies the vehicle type from the estimated size. The radar 100 transmits the vehicle type information or writes the vehicle type information to the recording medium 710. The correction data generation device 700 receives the vehicle type information or reads the vehicle type information from the recording medium 710, and identifies the vehicle type from the acquired vehicle type information. The vehicle type designation unit 713 designates the vehicle type indicated by the vehicle type information to the generation unit 714.

The generating unit 714 generates correction data 400 in which the correction amount, which is the difference between the first position and the reference position, and the first position are associated with each other. FIG. 13 is a diagram for explaining the first position and the reference position. The reference position 800 is the position of the reference part, which is the mounting part of the GNSS receiver. The GNSS receiver is installed in a specific part of the vehicle V, such as the center of gravity of the vehicle body. The first position 530 is determined by the distribution of the reflection points 500 on the vehicle body, and is often a position different from the reference position 800.

The generation unit 714 calculates a correction amount AY in the Y direction, which is the difference between the Y component of the first position 530 and the Y component of the reference position 800, and calculates a correction amount AX in the X direction, which is the difference between the X component of the first position 530 and the X component of the reference position 800. The first position 530 and the reference position 800 for which the difference is calculated are the first position 530 and the reference position 800 at the same time. In other words, the first identification unit 711 and the second identification unit 712 respectively identify the first position 530 and the reference position 800 at the same time from the first position data and the reference position data, respectively. However, if the detection of the first position 530 by the radar 100 and the detection of the reference position 800 by the RTK measurement are performed at different times, the first identification unit 711 identifies the first position 530 detected when the vehicle V is present at a specific location 310 of the lane, and the second identification unit 712 identifies the reference position 800 detected when the vehicle V is present at the specific location 310. In other words, it is sufficient to identify the first position 530 and the reference position 800 when the vehicle V is present at the same specific location 310.

The generating unit 714 associates the calculated correction amount AY with the Y component of the first position 530. The generating unit 714 associates the correction amount AY with the Y component of the first position 530 by the first position 530 and the reference position 800 at multiple times, or by the first position 530 and the reference position 800 at multiple points on the lane, thereby generating Y correction data. The generating unit 714 associates the calculated correction amount AX with the Y component of the first position 530. The generating unit 714 associates the correction amount AX with the Y component of the first position 530 by the first position 530 and the reference position 800 at multiple times, or by the first position 530 and the reference position 800 at multiple points on the lane, thereby generating X correction data.

Refer to FIG. 12 again. The generating unit 714 generates correction data for the vehicle type specified by the vehicle type specifying unit 713. When a small vehicle is specified by the vehicle type specifying unit 713, the generating unit 714 sets the data in which the correction amount AY and the Y component of the first position 530 are associated as the Y correction data 411 of the small vehicle correction data 410, and sets the data in which the correction amount AX and the Y component of the first position 530 are associated as the X correction data 412 of the small vehicle correction data 410. When a medium-sized vehicle is specified by the vehicle type specifying unit 713, the generating unit 714 sets the data in which the correction amount AY and the Y component of the first position 530 are associated as the Y correction data 421 of the medium-sized vehicle correction data 420, and sets the data in which the correction amount AX and the Y component of the first position 530 are associated as the X correction data 422 of the medium-sized vehicle correction data 420. When a large vehicle is specified by the vehicle type specification unit 713, the generation unit 714 sets the data associating the correction amount AY with the Y component of the first position 530 as Y correction data 431 of the large vehicle correction data 430, and sets the data associating the correction amount AX with the Y component of the first position 530 as X correction data 432 of the large vehicle correction data 430.

The output unit 715 outputs the generated correction data 400. For example, the output unit 715 transmits the correction data 400 to the radar 100 or another external device. In another example, the output unit 715 writes the correction data 400 to the recording medium 710 loaded in the writing device 706.

[1-7. Operation of the correction data generating device]
14 is a flowchart showing an example of an operation procedure of the correction data generating device according to the first embodiment. When the processor 701 starts the correction data generating program 708, the correction data generating device 700 executes the process described below.

The processor 701 acquires the first position data, for example, by receiving the first position data from the radar 100 or another external device, or by reading the first position data from the recording medium 710 (step S201).

The processor 701 acquires the reference position data, for example, by receiving the reference position data from the radar 100 or another external device, or by reading the reference position data from the recording medium 710 (step S202).

The processor 701 identifies the vehicle model for which the correction data is to be used, for example, by receiving a vehicle model specification from the user, by receiving vehicle model information from the radar 100 or another external device, or by reading vehicle model information from the recording medium 710 (step S203).

The processor 701 calculates a correction amount AY, which is the difference between the Y component of the first position 530 at the same time and the Y component of the reference position 800, and generates Y correction data for the specified vehicle model by associating the correction amount AY with the Y component of the first position 530. The processor 701 calculates a correction amount AX, which is the difference between the X component of the first position 530 at the same time and the X component of the reference position 800, and generates X correction data for the specified vehicle model by associating the correction amount AX with the Y component of the first position 530 (step S204).

The processor 701 outputs the correction data by transmitting the generated correction data to the radar 100 or another external device, or by writing the correction data to the recording medium 710 (step S205). This completes the operation of the correction data generating device 700.

[2. Second embodiment]
[2-1. Radar]
In this embodiment, the receiving circuit 115 of the radar 100 includes three or more receiving antennas, and detects the position (first position) of the vehicle V in the XYZ coordinate space. When the relative position between the radar 100 and the vehicle V changes, the distribution of the reflection points 500 on the vehicle body changes, causing a shift in not only the Y component and the X component of the first position, but also the Z component.

The radar 100 corrects not only the Y and X components of the first position, but also the Z component. FIG. 15 is a diagram showing an example of the configuration of correction data according to the second embodiment. The small vehicle correction data 410 includes Y correction data 411, X correction data 412, and Z correction data 413. The medium vehicle correction data 420 includes Y correction data 421, X correction data 422, and Z correction data 423. The large vehicle correction data 430 includes Y correction data 431, X correction data 432, and Z correction data 433. The Z correction data 413, 423, and 433 are used to correct the Z component of the first position. Specifically, the Z correction data 413, 423, and 433 indicate the correspondence between the Y component of the first position and the correction amount AZ in the Z direction.

Refer to FIG. 4. The correction unit 126 acquires the correction amounts AY, AX, and AZ corresponding to the first position identified by the identification unit 123 according to the correction data 400, and determines a second position obtained by correcting the first position using the acquired correction amounts AY, AX, and AZ. Specifically, the correction unit 126 acquires the correction amount AY corresponding to the Y component of the first position according to the Y correction data included in the correction data selected by the selection unit 125. The correction unit 126 acquires the correction amount AX corresponding to the Y component of the first position according to the X correction data included in the correction data selected by the selection unit 125. The correction unit 126 acquires the correction amount AZ corresponding to the Y component of the first position according to the Z correction data included in the correction data selected by the selection unit 125. The correction unit 126 corrects the Y component of the first position using the acquired correction amount AY, and determines the Y component of the second position. The correction unit 126 corrects the X component of the first position using the acquired correction amount AX to determine the X component of the second position. The correction unit 126 corrects the Z component of the first position using the acquired correction amount AZ to determine the Z component of the second position.

When the road in the target area 300 is inclined to the lane length, the height of the road surface changes according to the position of the vehicle V on the lane, and the distance in the Y direction between the radar 100 and the vehicle V changes. The distribution of the reflection points 500 on the vehicle body changes with such a change in the distance in the Y direction between the radar 100 and the vehicle V. By correcting the Z component of the first position, it is possible to correct the deviation of the Z component of the first position due to the road surface gradient. Naturally, even on a horizontal road surface with no incline, it is possible to correct the deviation of the Z component of the first position due to the change in the distribution of the reflection points 500 on the vehicle body due to the change in the position of the vehicle V in the Y direction by correcting the Z component of the first position.

[2-2. Correction data generating device]
In this embodiment, the correction data generating device 700 generates the correction data 400 for correcting the Z component of the first position.

Refer to FIG. 12. For example, the correction data generating device 700 receives first position data from the radar 100 or another external device, or reads out the first position data stored in the recording medium 710, and the first identifying unit 711 identifies the first position in the XYZ coordinate space from the acquired first position data. The first position data is time-series data that indicates the transition of the first position in the XYZ coordinates of the vehicle V.

For example, the correction data generating device 700 receives reference position data from an in-vehicle device of the vehicle V or another external device, or reads out reference position data stored in the recording medium 710, and the second identification unit 712 can identify the reference position in the XYA coordinate space from the acquired reference position data. The reference position data is time-series data that indicates the transition of the reference position in the XYZ coordinates of the vehicle V.

The first identification unit 711 identifies the first position 530 detected when the vehicle V is present at a specific location 310 on the lane, and the second identification unit 712 identifies the reference position 800 detected when the vehicle V is present at the specific location 310 (see FIG. 13). In other words, the first position 530 and the reference position 800 when the vehicle V is present at the same specific location 310 are identified.

In addition to the correction amounts AY and AX, the generation unit 714 calculates a correction amount AZ in the Z direction, which is the difference between the Z component of the first position 530 and the Z component of the reference position 800. The generation unit 714 associates the calculated correction amount AZ with the Y component of the first position 530. The generation unit 714 associates the correction amount AZ with the Y component of the first position 530 using the first position 530 and the reference position 800 at multiple times, or using the first position 530 and the reference position 800 at multiple points on the lane, thereby generating Z correction data.

When a small vehicle is specified by the vehicle type specification unit 713, the generation unit 714 sets the data associating the correction amount AZ with the Y component of the first position 530 as Z correction data 413 of the small vehicle correction data 410. When a medium-sized vehicle is specified by the vehicle type specification unit 713, the generation unit 714 sets the data associating the correction amount AZ with the Y component of the first position 530 as Z correction data 423 of the medium-sized vehicle correction data 420. When a large vehicle is specified by the vehicle type specification unit 713, the generation unit 714 sets the data associating the correction amount AZ with the Y component of the first position 530 as Z correction data 433 of the large vehicle correction data 430.

3. Other embodiments
In the above-described embodiment, the vehicle type identification unit 124 identifies the vehicle type (compact vehicle, medium-sized vehicle, large vehicle) of the vehicle V corresponding to the group by the Y-direction distance (hereinafter referred to as "Y distance") between the two reflection points 500 that are the furthest apart in the Y direction among the reflection points 500 belonging to the same group and the X-direction distance (hereinafter referred to as "X distance") between the two points that are the furthest apart in the X direction, but is not limited to this. The Z-direction distance (hereinafter referred to as "Z distance") between the two points that are the furthest apart in the Z direction among the grouped reflection points 500 may be used to identify the vehicle type of the vehicle V. For example, the vehicle type identification unit 124 may identify the vehicle type of the vehicle V by using the Z distance in addition to the Y distance and X distance of the grouped reflection point group, or may identify the vehicle type of the vehicle V by using only the Z distance without using the Y distance and X distance of the grouped reflection point group. Furthermore, the vehicle type identification unit 124 may identify the vehicle type of the vehicle V by using any one of the Y distance and the X distance of the grouped reflection point group and the Z distance.

In the above-described embodiment, the correction data generating device 700 acquires the first position data indicating the first position actually detected by the radar 100, and generates the correction data 400 using the acquired first position data, but this is not limited to the above. A simulation result of the position detection of the radar 100 by a simulator may be used to generate the correction data 400. For example, the position detection of the vehicle V by the radar 100 is simulated by a ray tracing method, and simulation data indicating the simulated detection result of the first position is provided to the correction data generating device 700. The first identification unit 711 identifies the first position from the simulation data. The generation unit 714 generates the correction data 400 in which the correction amount, which is the difference between the first position obtained by the simulation and the reference position, and the first position obtained by the simulation are associated with each other.

[4. Effects]
The radar 100 according to the embodiment includes receiving antennas 115a and 115b, a determination unit 123, and a correction unit 126. The receiving antennas 115a and 115b receive reflected waves by the vehicle V of the radio waves irradiated to the target area 300. The determination unit 123 determines a first position 530 of the vehicle V based on the reflected waves received by the receiving antennas 115a and 115b. The correction unit 126 acquires a correction amount corresponding to the first position 530 identified by the determination unit 123 according to the correction data 400 indicating the correspondence between the first position 530 of the vehicle V and the correction amount, and determines a second position by correcting the first position 530 by the acquired correction amount. As a result, the first position 530 can be corrected by the correction amount according to the first position 530, so that the detection accuracy of the position of the vehicle V by the radar 100 can be stabilized regardless of the positional relationship between the radar 100 and the vehicle V.

The first position 530 may include a Y component and an X component. The correction data 400 may include Y correction data (first correction data) 411, 421, 431 used to correct the Y component and X correction data (second correction data) 412, 422, 432 used to correct the X component. The correction unit 126 may determine the Y component of the second position according to the Y correction data 411, 421, 431, and determine the X component of the second position according to the X correction data 412, 422, 432. This makes it possible to stabilize the detection accuracy of the position of the vehicle V by the radar 100 in a space including the Y direction and the X direction.

The Y correction data 411, 421, 431 may indicate the correspondence between the Y component of the first position 530 and the correction amount AY of the Y component. The X correction data 412, 422, 432 may indicate the correspondence between the Y component of the first position 530 and the correction amount AX of the X component. When the relative position in the Y direction between the radar 100 and the vehicle V changes, the reflection surface of the radio wave on the vehicle body changes. With the above configuration, the Y component and the X component of the first position 530 can be corrected according to the relative position in the Y direction between the radar 100 and the vehicle V, and the detection accuracy of the position of the vehicle V by the radar 100 can be stabilized.

The first position 530 may further include a Z component. The correction data 400 may further include Z correction data (third correction data) 413, 423, 433 used to correct the Z component. The correction unit 126 may determine the Z component of the second position according to the Z correction data 413, 423, 433. This makes it possible to stabilize the detection accuracy of the position of the vehicle V by the radar 100 in a space including the Y direction, the X direction, and the Z direction.

The Z correction data 413, 423, 433 may indicate the correspondence between the Y component of the first position 530 and the correction amount AZ of the Z component. When the relative position in the Y direction between the radar 100 and the vehicle V changes, the radio wave reflection surface on the vehicle body changes. With the above configuration, the Z component of the first position 530 can be corrected according to the relative position in the Y direction between the radar 100 and the vehicle V, and the detection accuracy of the position of the vehicle V by the radar 100 can be stabilized.

The correction data 400 may include first vehicle type correction data used for a first vehicle type whose vehicle size is defined in a predetermined first division, and second vehicle type correction data used for a second vehicle type whose vehicle size is defined in a second division different from the first division. As an example, assuming that the first vehicle type is a small car and the second vehicle type is a medium-sized car, the first vehicle type correction data is small car correction data 410, and the second vehicle type correction data is medium car correction data 420. The radar 100 may further include a vehicle type identification unit 124. The vehicle type identification unit 124 identifies whether the vehicle V belongs to a small car or a medium-sized car based on the reflected waves received by the receiving antennas 115a and 115b. When the vehicle V is identified as belonging to a small car, the correction unit 126 may acquire a correction amount corresponding to the first position 530 according to the small car correction data 410. If the vehicle V is identified as a medium-sized vehicle, the correction unit 126 may obtain a correction amount corresponding to the first position 530 according to the medium-sized vehicle correction data 420. The error in the position detected by the radar 100 varies depending on the vehicle size. With the above configuration, the position detected by the radar 100 can be corrected with a correction amount according to the vehicle size.

The identification unit 123 may obtain a representative value of multiple reflection points 500 detected from reflected waves from the same vehicle, and set the representative value to the first position 530. This makes it possible to stabilize the first position 530 detected by the radar 100. By correcting such a first position 530, it is possible to stabilize the detection accuracy of the radar 100.

The representative value may be the center of gravity of the multiple reflection points 500. This makes it possible to prevent the first position 530 from suddenly changing in response to a change in the positional relationship between the radar 100 and the vehicle V in the Y direction. This makes it possible to stabilize the detection accuracy of the radar 100.

The correction data generating device 700 includes a first identification unit 711, a second identification unit 712, and a generation unit 714. The first identification unit 711 identifies a first position 530 in a predetermined coordinate space, which is the position of the vehicle V detected by the radar 100. The second identification unit 712 identifies a reference position 800 in the above coordinate space, which is the position of a reference part of the vehicle V. The generation unit 714 generates correction data 400 in which a correction amount, which is the difference between the first position 530 and the reference position 800, and the first position 530 are associated with each other. This makes it possible to generate correction data 400 for correcting the position detected by the radar 100 according to the relative positions of the radar 100 and the vehicle V.

The first position 530 may include a Y component and an X component. The correction data 400 may include Y correction data (first correction data) 411, 421, 431 and X correction data (second correction data) 412, 422, 432. The Y correction data 411, 421, 431 is data in which the correction amount AY of the Y component of the first position 530 and the first position 530 are associated with each other. The X correction data 412, 422, 432 is data in which the correction amount AX of the X component of the first position 530 and the first position 530 are associated with each other. This makes it possible to generate correction data 400 for correcting the position of the vehicle V detected by the radar 100 in a space including the Y direction and the X direction.

The Y correction data 411, 421, and 431 may indicate the correspondence between the Y component of the first position 530 and the correction amount AY of the Y component. The X correction data 412, 422, and 432 may indicate the correspondence between the Y component of the first position 530 and the correction amount AX of the X component. This makes it possible to generate correction data 400 for correcting each of the Y component and X component of the first position 530 according to the relative positions of the radar 100 and the vehicle V in the Y direction.

The first position 530 may further include a Z component. The correction data 400 may further include Z correction data (third correction data) 413, 423, 433 in which the correction amount AZ of the Z component of the first position 530 and the first position 530 are associated with each other. This makes it possible to generate correction data 400 for correcting the position of the vehicle V detected by the radar 100 in a space including the Y direction, the X direction, and the Z direction.

The Z correction data 413, 423, and 433 may indicate the correspondence between the Y component of the first position 530 and the correction amount AZ of the Z component. This makes it possible to generate correction data 400 for correcting the Z component of the first position 530 according to the relative position in the Y direction between the radar 100 and the vehicle V.

The first identification unit 711 may identify the first position 530 of the first vehicle belonging to the first vehicle type whose vehicle size is defined by a predetermined first division. The second identification unit 712 may identify the reference position 800 of the first vehicle. The generation unit 714 may generate first vehicle type correction data which is correction data for the first vehicle type. The first vehicle type correction data is data in which the correction amount which is the difference between the first position 530 of the first vehicle and the reference position 800 of the first vehicle, and the first position 530 of the first vehicle are associated with each other. As an example, assuming that the first vehicle type is a compact car, the first identification unit 711 identifies the first position 530 of the vehicle V which is a compact car, the second identification unit 712 identifies the reference position 800 of the vehicle V which is a compact car, and the generation unit 714 generates the correction data 410 for the compact car. The small vehicle correction data 410 is data in which a correction amount, which is a difference between the first position 530 of the vehicle V, which is a small vehicle, and the reference position 800 of the vehicle V, which is a small vehicle, and the first position 530 of the vehicle V, which is a small vehicle, are associated with each other. The first identification unit 711 may identify the first position 530 of a second vehicle belonging to a second vehicle type defined in a second category whose vehicle size is different from the first category. The second identification unit 712 may identify the reference position 800 of the second vehicle. The generation unit 714 may generate second vehicle type correction data, which is correction data for the second vehicle type. The second vehicle type correction data is data in which a correction amount, which is a difference between the first position 530 of the second vehicle and the reference position 800 of the second vehicle, and the first position 530 of the second vehicle are associated with each other. As an example, assuming that the second vehicle type is a medium-sized vehicle, the first identification unit 711 identifies the first position 530 of the vehicle V, which is a medium-sized vehicle, the second identification unit 712 identifies the reference position 800 of the vehicle V, which is a medium-sized vehicle, and the generation unit 714 generates the correction data for medium-sized vehicles 420. The correction data for medium-sized vehicles 420 is data in which the correction amount, which is the difference between the first position 530 of the vehicle V, which is a medium-sized vehicle, and the reference position 800 of the vehicle V, which is a medium-sized vehicle, and the first position 530 of the vehicle V, which is a medium-sized vehicle, are associated with each other.

The first position 530 may be a representative value of multiple reflection points 500 detected by the radar 100 from the reflected wave from the same vehicle. This makes it possible to stabilize the first position 530, and using such a first position 530, it is possible to generate correction data for accurately correcting the detected position of the radar 100.

The representative value may be the center of gravity of the multiple reflection points 500. This makes it possible to prevent the first position 530 from suddenly changing in response to a change in the positional relationship between the radar 100 and the vehicle V in the Y direction. Using such a first position 530, it is possible to generate correction data 400 for accurately correcting the detection position of the radar 100.

The first identification unit 711 may identify the first position 530 calculated by a simulator of the radar 100. This makes it possible to generate the correction data 400 without actually operating the radar 100.

[5. Supplementary Notes]
The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes the meaning equivalent to the claims and all modifications within the scope thereof.

100 Radar (radio radar for infrastructure)
REFERENCE SIGNS LIST 101 Transmitting/receiving surface 102 Radar main body 103 Depression angle adjustment section 104 Horizontal angle adjustment section 105 Roll angle adjustment section 111 Processor 112 Non-volatile memory 113 Volatile memory 114 Transmitting circuit 114a Transmitting antenna 115 Receiving circuit 115a, 115b Receiving antenna 116 Communication interface (communication I/F)
117 Data correction program 121 Input unit 122 Grouping unit 123 Identification unit 124 Vehicle type identification unit 125 Selection unit 126 Correction unit 127 Output unit 200 Arm 300 Target area 310 Specific location 400 Correction data 410 Small vehicle correction data (first vehicle type correction data, second vehicle type correction data)
411 Y correction data (first correction data)
412 X correction data (second correction data)
413 Z correction data (third correction data)
420 Correction data for medium-sized vehicles (correction data for the first vehicle type, correction data for the second vehicle type)
421 Y correction data (first correction data)
422 X correction data (second correction data)
423 Z correction data (third correction data)
430 Large vehicle correction data (first vehicle type correction data, second vehicle type correction data)
431 Y correction data (first correction data)
432 X correction data (second correction data)
433 Z correction data (third correction data)
500 Reflection point 510, 520 Waveform 511, 521 Peak point 530 First position 600 Second position 700 Correction data generating device 701 Processor 702 Non-volatile memory 703 Volatile memory 704 Input device 705 Display device 706 Writing device 707 Communication interface (communication I/F)
708 Correction data generation program 710 Recording medium 711 First identification unit 712 Second identification unit 713 Vehicle type designation unit 714 Generation unit 715 Output unit 800 Reference position V Vehicle

Claims (20)

A receiving antenna configured to receive a reflected wave of a radio wave irradiated to a target area by a vehicle;
an identification unit configured to identify a first position of the vehicle based on the reflected wave received by the receiving antenna;
a correction unit configured to acquire a correction amount corresponding to the first position identified by the identification unit according to correction data indicating a correspondence relationship between a first position of a vehicle and a correction amount, and to determine a second position by correcting the first position by the acquired correction amount;
Equipped with
Radio radar for infrastructure use. The first position includes a lane length direction component and a lane width direction component,
the correction data includes first correction data used to correct the lane length direction component and second correction data used to correct the lane width direction component,
The correction unit determines a lane length direction component of the second position according to the first correction data, and determines a lane width direction component of the second position according to the second correction data.
The radio wave radar for infrastructure use according to claim 1. The first correction data indicates a correspondence relationship between a lane longitudinal direction component of the first position and a correction amount of the lane longitudinal direction component,
The second correction data indicates a correspondence relationship between a lane length direction component of the first position and a correction amount of the lane width direction component.
The radio wave radar for infrastructure use according to claim 2. The first position further includes a height direction component,
the correction data further includes third correction data used to correct the height direction component,
The correction unit determines a height direction component of the second position in accordance with the third correction data.
The radio wave radar for infrastructure use according to claim 2 or 3. The third correction data indicates a correspondence relationship between a lane length direction component of the first position and a correction amount of the height direction component.
The radio wave radar for infrastructure use according to claim 4. the correction data includes first vehicle type correction data used for a first vehicle type whose vehicle size is defined in a predetermined first division, and second vehicle type correction data used for a second vehicle type whose vehicle size is defined in a second division different from the first division,
the infrastructure radio wave radar further includes a vehicle type identification unit that identifies whether the vehicle belongs to the first vehicle type or the second vehicle type based on the reflected wave received by the receiving antenna,
the correction unit, when the vehicle is identified as belonging to the first vehicle type, obtains a correction amount corresponding to the first position according to the first vehicle type correction data, and, when the vehicle is identified as belonging to the second vehicle type, obtains a correction amount corresponding to the first position according to the second vehicle type correction data.
The radio wave radar for infrastructure use according to any one of claims 1 to 5. The identification unit acquires a representative value of a plurality of reflection points detected from a reflected wave from a same vehicle, and sets the representative value to the first position.
The radio wave radar for infrastructure use according to any one of claims 1 to 6. The representative value is a center of gravity of the plurality of reflection points.
The radio wave radar for infrastructure use according to claim 7. Identifying a first position of the vehicle based on a reflected wave of a radio wave irradiated by the infrastructure radio wave radar into a target area by the vehicle;
acquiring a correction amount corresponding to a first position of a vehicle according to correction data indicating a correspondence relationship between the first position and a correction amount, and determining a second position by correcting the first position by the acquired correction amount;
Including,
A method for correcting data from radio radar for infrastructure use. a first identification unit configured to identify a first position in a predetermined coordinate space, the first position being a position of a vehicle detected by an infrastructure radio wave radar;
a second identification unit configured to identify a reference position in the coordinate space, the reference position being a position of a reference portion of the vehicle;
a generating unit configured to generate correction data in which a correction amount, which is a difference between the first position and the reference position, and the first position are associated with each other;
Equipped with
Correction data generating device. The first position includes a lane length direction component and a lane width direction component,
The correction data includes first correction data in which a correction amount of the lane length direction component of the first position and the first position are associated with each other, and second correction data in which a correction amount of the lane width direction component of the first position and the first position are associated with each other.
The correction data generating device according to claim 10. The first correction data indicates a correspondence relationship between a lane longitudinal direction component of the first position and a correction amount of the lane longitudinal direction component,
The second correction data indicates a correspondence relationship between a lane length direction component of the first position and a correction amount of the lane width direction component.
The correction data generating device according to claim 11. The first position further includes a height direction component,
the correction data includes third correction data in which a correction amount of the height direction component of the first position and the first position are associated with each other;
13. The correction data generating device according to claim 11 or 12. The third correction data indicates a correspondence relationship between a lane length direction component of the first position and a correction amount of the height direction component.
The correction data generating device according to claim 13. The first identification unit identifies the first position of a first vehicle belonging to a first vehicle type whose vehicle size is defined in a predetermined first category;
The second identification unit identifies the reference position of the first vehicle,
The generation unit generates first vehicle type correction data, which is correction data for the first vehicle type,
the first vehicle type correction data is data in which a correction amount, which is a difference between the first position of the first vehicle and the reference position of the first vehicle, and the first position of the first vehicle are associated with each other,
the first identification unit identifies the first position of a second vehicle belonging to a second vehicle type defined in a second category whose vehicle size is different from the first category;
The second identification unit identifies the reference position of the second vehicle,
The generation unit generates second vehicle type correction data which is correction data for the second vehicle type,
The second vehicle type correction data is data in which a correction amount, which is a difference between the first position of the second vehicle and the reference position of the second vehicle, and the first position of the second vehicle are associated with each other.
The correction data generating device according to any one of claims 10 to 14. The first position is a representative value of a plurality of reflection points detected by the infrastructure radio wave radar from a single vehicle.
The correction data generating device according to any one of claims 10 to 15. The representative value is a center of gravity of the plurality of reflection points.
The correction data generating device according to claim 16. The first identification unit identifies the first position calculated by a simulator of the infrastructure radio wave radar.
The correction data generating device according to any one of claims 10 to 17. Identifying a first position in a predetermined coordinate space, which is a position of the vehicle detected by an infrastructure radio wave radar;
identifying a reference position in the coordinate space that is a position of a reference part of the vehicle;
generating correction data in which a correction amount, which is a difference between the first position and the reference position, and the first position are associated with each other;
Including,
A method for generating correction data. A computer program for generating correction data for correcting a vehicle position detected by an infrastructure radio wave radar, comprising:
The computer includes:
Identifying a first position in a predetermined coordinate space, which is a position of the vehicle detected by an infrastructure radio wave radar;
identifying a reference position in the coordinate space that is a position of a reference part of the vehicle;
generating correction data in which a correction amount, which is a difference between the first position and the reference position, and the first position are associated with each other;
Execute the
Computer program.

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