Correction apparatus and correction method

Abstract

To provide a correction device for correcting current detection information of a detection object acquired from a detection device to corrected detection information so as to have high accuracy necessary for a vehicle to safely travel.SOLUTION: Provided is a correction device that corrects current detection information that is current detection information regarding a detection target acquired from a detection device, the correction device including a received information storage unit that receives the current detection information from the detection device, and stores the current detection information and past detection information that is past current detection information, and a correction unit that calculates a relative speed and a relative distance by comparing past and current from the current detection information and a plurality of pieces of past detection information, and corrects the current detection information to corrected detection information using the calculated relative distance.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a correction device and a correction method.

[0002] For example, Patent Document 1 discloses an autonomous vehicle equipped with a detection device (which may hereinafter be referred to as a sensor). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2020-15490 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional methods such as those described in Patent Document 1, depending on the detection device used and the detection situation, the vehicle may not be able to obtain highly accurate detection information with little error in the position of the detection target from the detection device, which is necessary for the vehicle to travel safely.

[0005] One aspect of an embodiment of the present invention aims to provide a correction device that corrects current detection information, which is current detection information of a detection object obtained from a detection device, into corrected detection information so that it has the high accuracy required for a vehicle to travel safely.

[0006] A correction device is provided that corrects current detection information, which is current detection information of a detection target obtained from a detection device, and includes a received information storage unit that receives the current detection information from the detection device and stores the current detection information and past detection information, which is past current detection information, and a correction unit that compares the past and present from the current detection information and multiple pieces of past detection information to calculate relative speed and relative distance, and corrects the current detection information to corrected detection information using the calculated relative distance.

[0007] Provided is a correction method for correcting current detection information, which is current detection information of a detection target obtained from a detection device, comprising: a first step of receiving the current detection information from the detection device and storing the current detection information and past detection information, which is past current detection information; and a second step of comparing the past and present from the current detection information and multiple pieces of past detection information to calculate relative speed and relative distance, and correcting the current detection information to corrected detection information using the calculated relative distance. [Effects of the Invention]

[0008] According to the present invention, a correction device can be realized that corrects current detection information to corrected detection information that enables detection targets that cannot be detected by the current detection information to be detected with the high accuracy required for the vehicle to run safely. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an outline of a correction system according to this embodiment. [Figure 2] FIG. 2 is a block diagram showing the configuration of the correction system according to this embodiment. [Figure 3] FIG. 3 is a schematic diagram showing the state of correction according to this embodiment. [Figure 4] FIG. 4 is a diagram illustrating the processing used in the correction device according to this embodiment. [Figure 5] FIG. 5 is a conceptual diagram showing the state of detection by the detection device according to this embodiment. [Figure 6] FIG. 6 is a diagram showing corrected detection information presented on the presentation device. [Figure 7] FIG. 7 is a sequence diagram illustrating the correction function. [Figure 8] FIG. 8 is a diagram showing information stored in the received information storage unit. [Figure 9] FIG. 9 is a flowchart showing the procedure of the correction process. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Embodiment 1) An overview of the correction system 1 will be described using the schematic diagram shown in Fig. 1. As shown in Fig. 1, the correction system 1 in this embodiment includes a detection device 3 that detects a detection target 2 and generates current detection information, and a correction device 4 that corrects the current detection information from the detection device 3 to generate corrected detection information. The current detection information is the current detection information of the detection target 2 detected by the detection device 3.

[0011] For example, the detection target 2 may be a person, animal, or obstacle, the correction device 4 may be a desktop or notebook personal computer (PC) or general-purpose computer, and the detection device 3 may be a LiDAR (Light Detection And Ranging) device.

[0012] The correction system 1 is installed, for example, on a vehicle 7 traveling in a direction 6 along a road 5 on which a detection target 2 exists. The correction system 1 may further include a measurement device 8 that measures the translational motion and rotational motion of the vehicle 7, as shown by the dashed line in Fig. 2. The measurement device 8 is, for example, an inertial measurement unit (IMU).

[0013] The correction system 1 may further include a presentation device 15 that presents the detection target 2 detected by the current detection information and the detection target detected by the corrected detection information described below, as indicated by the dashed line in Fig. 2. The presentation device 15 may be, for example, a display, a smartphone, or a tablet terminal.

[0014] 1, during the period from past time tp, which is a past time, to current time t, which is the present time, the vehicle 7 travels from point A to point B, and the detection object 2 moves from point C to point D. Note that during the period from past time tp to current time t, the detection object 2 and the vehicle 7 may move any distance in the road width direction.

[0015] For example, the period from past time tp to current time t is set to about several seconds, and the road width is set to the width of road 5. The current detection information is the current detection information of the detection target 2 detected by the detection device 3 at current time t, and one piece of the past detection information is the current detection information of the detection target 2 at past time tp, detected by the detection device 3 at past time tp.

[0016] At past time tp, scanning line 9 sent from detection device 3 hits detection target 2, and detection device 3 detects detection target 2 based on the past detection information, but at current time t, scanning line 10 sent from detection device 3 does not hit detection target 2, and detection device 3 does not detect detection target 2 based on the current detection information.

[0017] In the conventional technology that does not use the correction device 4, when the vehicle 7 continues to travel in the traveling direction 6 from the current time t, the detection device 3 does not detect the detection target 2 at the current time t, even though the detection target 2 is present. For this reason, in the conventional technology that does not use the correction device 4, the vehicle 7 cannot take a behavior that avoids the detection target 2.

[0018] The configuration of the correction system 1 according to this embodiment will be described using the block diagram shown in Fig. 2. As shown in Fig. 2, the detection device 3 includes a detection information acquisition unit 20 that acquires current detection information and a detection information transmission unit 21 that transmits the current detection information to the correction device 4.

[0019] The correction device 4 includes a central processing unit 22, a main memory device 23, an auxiliary memory device 24, and a communication device 25. The central processing unit 22 is, for example, a CPU (Central Processing Unit), and executes processing by reading out a program stored in the main memory device 23.

[0020] The main storage device 23 is, for example, a RAM (Random Access Memory) and includes a control unit 26 and a storage unit 27. The control unit 26 includes a correction unit 28, which is also a program. The control unit 26 may include a correction assistant unit 29, which is also a program, and a presentation information control unit 30, as shown by the dashed line in FIG. 2 .

[0021] The storage unit 27 includes a received information storage unit 31 that stores current detection information received from the detection device 3. The storage unit 27 may also include an offset information storage unit 32 that stores offset information, as indicated by the dashed line in FIG.

[0022] Current detection information stored in the received information storage unit 31 over time becomes past detection information. The received information storage unit 31 may also store current measurement information received from the measurement device 8. The measurement device 8 includes a measurement information acquisition unit 36 ​​that acquires the current measurement information and a measurement information transmission unit 37 that transmits the current measurement information to the correction device 4. Current measurement information stored in the received information storage unit 31 over time becomes past measurement information.

[0023] The auxiliary storage device 24 is a non-volatile storage device such as a ROM (Read Only Memory), SSD (Solid State Drive), HDD (Hard Disk Drive), or MicroSD card, and stores, for example, the control unit 26, which is a program, even when the correction device 4 is not powered on.

[0024] The communication device 25 is, for example, a network card such as a wired or wireless LAN (Local Area Network) module, a Bluetooth module, or a USB (Universal Serial Bus) 3.0 module.

[0025] The communication device 25 may be, for example, a graphic board that complies with a connection standard. The communication device 25 includes a detection information receiving unit 33. The communication device 25 may also include a measurement information receiving unit 34 and a presentation information transmitting unit 35, as shown by the dashed lines in FIG. 2 .

[0026] The correction unit 28 compares the past and present information based on the current detection information and at least one of the multiple pieces of past detection information to calculate the relative speed and relative distance 11. The correction unit 28 corrects the current detection information to corrected detection information using the calculated relative distance 11. The correction to the corrected detection information may be, for example, the current detection information to which thinned-out past detection information according to the relative distance 11 has been added.

[0027] For example, the relative speed of the vehicle 7 between the current time t and the past time tp can be calculated from the difference between the current speed v of the vehicle 7 at the current time t and the past speed vp of the vehicle 7 at the past time tp. The speed of the vehicle 7 is obtained, for example, from an on-board device such as a speedometer (not shown) mounted on the vehicle 7.

[0028] For example, the relative distance 11 can be calculated simply from the product of the average speed va of the current speed v and the past speed Vp, the current time t, and the elapsed time te from the past time tp to the current time t.

[0029] The correction assistance unit 29 may associate the current detection information with the current measurement information or past measurement information whose measurement time is closest to the detection time of the current detection information, and correct the current detection information to corrected detection information based on the associated current measurement information or past measurement information whose measurement time is closest to the detection time of the current detection information.

[0030] The presentation information control unit 30 generates and controls presentation information, which is information to be presented on the presentation device 15. For example, the presentation information includes information on the position of the detection device 3 at past time tp and current time t, information on the position of the detection target 2 at current time t, and information on the relative distance 11. The presentation device 15 includes a presentation information receiving unit 38 that receives the presentation information and a presentation unit 39 that presents the presentation information.

[0031] The correction process according to this embodiment will be described with reference to the schematic diagram shown in Fig. 3. As shown in the side view of Fig. 3, the correction device 4 may also correct the shake 12 through correction by the correction assistant section 29.

[0032] In FIG. 3, the detection target 2, the detection device 3, the vehicle 7, and the scanning line 10 at the current time t are depicted by solid lines, and the detection target 2, the detection device 3, the vehicle 7, and the scanning line 9 at the past time tp are depicted by dashed lines.

[0033] The correction device 4 is capable of correcting not only the longitudinal direction of the vehicle 7 such as the relative distance 11, but also the vertical direction of the vehicle 7 such as the blur 12. The blur 12 may be included in the presented information. For example, the longitudinal direction of the vehicle 7 refers to the horizontal direction, and the vertical direction of the vehicle 7 refers to the vertical direction.

[0034] 3, the correction device 4 can also correct the rotation direction of the vehicle 7, such as the deviation 13, through correction by the correction assisting unit 29. For example, the rotation direction of the vehicle 7 is related to the movement in the width direction of the road 5. Note that the deviation 13 may be included in the presented information.

[0035] Regarding the deviation 12, when the vehicle 7 passes through an inclined area such as a slope, it is necessary to separately input information about the inclination into the correction device 4 in order to make an accurate correction. Furthermore, regarding the deviation 13, when the vehicle 7 passes through a road 5 with two or more lanes, it is necessary to input information about the lanes into the correction device 4 in order to make an accurate correction.

[0036] The process used by the correction device according to this embodiment will be described with reference to Fig. 4. When the past detection information is adjusted to fall within a predetermined range 71 by referring to a normal distribution 70 based on the current detection information, the correction device 4 does not need to refer to the past detection information, which is likely to have a value that is far from the current detection information.

[0037] The normal distribution 70 indicates the distribution of the probability that the vehicle 7 can detect the detection target 2 over time. For example, the range of time te is set as the range in which the detection target 2 can be detected with a probability of about 60% based on the normal distribution 70.

[0038] The offset information storage unit 32 may store a time te for each driving environment, such as driving location, driving time zone, or weather, or for each type of detection target 2, to determine a predetermined range of the probability of presence, and may not use past detection information or past measurement information for a range that is longer than the time te.

[0039] The offset information storage unit 32 may store a time te for each driving environment, such as driving location, driving time zone, or weather, or for each type of detection target 2, in order to determine a predetermined range of the probability of presence, and the time te may be used in accordance with the driving environment or the type of detection target 2.

[0040] Furthermore, a trained model may be stored in the offset information storage unit 32, and the time te may be determined by the trained model stored in the offset information storage unit 32. For example, the trained model receives inputs of the driving environment, such as the driving location, driving time zone, and weather, and the type of detection target 2, and outputs the time te.

[0041] For example, the driving environment may be a general road or a highway, the driving time may be day or night, and the weather may be rainy or sunny, and the time te that exists with a probability of about 60% varies depending on each driving environment.

[0042] The detection process by the detection device 3 according to this embodiment will be described using the conceptual diagram shown in Fig. 5. Fig. 5 shows an example in which the detection target 2 is not moving. As shown in Fig. 5, the detection device 3 searches for search locations 51, 52, 53, and 54 at the current time t, and searches for search locations 55, 56, 57, and 58 at the past time tp.

[0043] For example, since detection object 2 is detected at search points 51, 52, 53, and 54, all of these become current detection information, while among search points 55, 56, 57, and 58, detection object 2 is only detected at search point 58, so only search point 58 becomes past detection information.

[0044] The correction unit 28 may correct each piece of current detection information detected from at least two or more detection targets 2 into corrected detection information. This allows the correction device 4 to correct the current detection information into corrected detection information that enables more accurate detection of the detection target 2, even when the detection target 2 has a complex shape. For example, the current detection information detected from two or more detection targets 2 refers to the current detection information detected at search locations 51, 52, 53, and 54.

[0045] For example, if detection object 2 is detected only in search location 51, it is impossible to determine whether detection object 2 is a circle, a triangle 50, or a doll. If detection object 2 is detected in search locations 51, 52, 53, and 54, it is possible to narrow down whether detection object 2 is at least a triangle 50 or a doll.

[0046] Furthermore, the detection device 3 may search for search locations 59, 60, 61, and 62 by correction using information from the measurement device 8. Among the locations of the search locations 59, 60, 61, and 62, the detection target 2 is detected only at the location of the search location 62, so the search location 62 is added as corrected detection information.

[0047] For example, if search location 58 is added as corrected detection information to the past detection information, it is determined that detection target 2 is more complex than a triangle. Similarly, if search location 62 is added as corrected detection information, it is determined that detection target 2 is more complex than a triangle.

[0048] The corrected detection information presented on the presentation device 15 will be described with reference to Fig. 6. As shown in Fig. 6, the presentation information presented on the presentation device 15 includes information on the position of the detection device 3 at past time tp and current time t, information on the position of the detection target 2 at current time t, and information on the relative distance 11. The presentation device 15 may also present blur 12 and deviation 13 included in the presentation information.

[0049] The correction device 4 transmits information presenting the detection target 2 detected by the current detection information and the detection target 2 detected by the corrected detection information to the presentation device 15. This allows the user of the correction device 4 to refer to the information presented by the presentation device 15 and set more appropriate correction settings.

[0050] As shown in Figure 6, target object 2 is not detected in scanning line 10, but is detected in scanning line 9 after correction that takes relative distance 11 into account. Target object 2 is also detected in scanning line 9' after correction that takes blur 12 into account. Target object 2 is also detected by taking deviation 13 into account, just like relative distance 11 and blur 12.

[0051] For example, the user of the correction device 4 compares the relative distance correction screen 76 and the blur correction screen 77 on the correction screen 75, determines that the detection target 2 is more clearly detected on the blur correction screen 77 than on the relative distance correction screen 76, and selects blur correction to set the appropriate correction.

[0052] In Figure 6, scanning line 9 and scanning line 9' are shown as dashed lines and scanning line 10 as a solid line, but in actual presentation, scanning line 9 may be shown in red, scanning line 9' in blue, and scanning line 10 in black, for example.

[0053] The correction function will be described with reference to the sequence diagram shown in Fig. 7. As shown in Fig. 7, when the correction device 4 is powered on and enters an activated state, it executes a communication information control process S10, which will be described later, and receives detection information from the detection device 3, which has been powered on and entered an activated state (S1, S3, S5).

[0054] Furthermore, when the correction device 4 is powered on and enters an activated state, it receives current measurement information from the measuring device 8 that has been powered on and entered an activated state (S2, S4, S6). For example, the correction device 4 starts the correction process S20 described below when it receives two or more pieces of current detection information with different timestamps that are received asynchronously. Note that the correction device 4 may start the correction process S20 when it receives current measurement information in addition to current detection information.

[0055] 8, a description will be given of the information stored in the reception information storage unit 31. A detection information table TB1 is stored in the reception information storage unit 31. The reception information storage unit 31 may also store a measurement information table TB2.

[0056] The detection information table TB1 stores, for example, a timestamp in terms of year, month, date, hour, minute, and second, and position information in xyz coordinates in the x direction, which is the forward / backward direction of the vehicle 7 relative to the detection device 3, the y direction, which is the upward / downward direction of the vehicle 7, and the z direction, which is the rotational direction of the vehicle 7.

[0057] For example, the timestamps in the detection information table TB1 are in units of 100 milliseconds, and the time precision of the stored current detection information and past detection information is in units of 100 milliseconds. The location information stored in the detection information table TB1 is the location information of the search location 51 detected as detection information, and is stored as location information such as p1x, p1y, and p1z.

[0058] The measurement information table TB2 records, for example, timestamps in year, month, day, hour, minute, and second format, as well as acceleration and angular velocity. Note that the timestamps in the measurement information table TB2 are recorded in 10 millisecond units, and the time precision of the stored current measurement information and past measurement information is 10 millisecond units.

[0059] For example, acceleration is information such as ax, ay, and az, which are the accelerations in the x, y, and z directions, respectively, and angular velocity is information such as rx, ry, and rz, which are the angular velocities around the x, y, and z directions, respectively.

[0060] The processing procedure of the correction process S20 will be described using the flowchart shown in Fig. 9. As shown in Fig. 9, the correction device 4 performs a communication information control process S10 before the correction process S20. In the communication information control process S10, the correction unit 28 performs initialization (S11) and determines whether or not two or more pieces of current detection information with different timestamps have been received (S12).

[0061] If two or more pieces of current detection information with different timestamps are received, the received information storage unit 31 stores the current detection information and the past detection information, and the process proceeds to the correction process S20 (S12: YES).

[0062] If two or more pieces of currently detected information with different timestamps have not been received, step S12 is performed again, and subsequent processing is put on hold until two or more pieces of currently detected information with different timestamps are received (S12: NO).

[0063] Note that initialization refers to, for example, setting information stored in the offset information storage unit 32. In the communication information control process S10, as shown by the dashed line in Fig. 9, the correction assist unit 29 may further determine whether or not it has received current measurement information in addition to the current detection information (S13).

[0064] If current measurement information is received in addition to current detection information, the received information storage unit 31 stores the current measurement information, and the process proceeds to correction process S20 (S13: YES). If current measurement information is not received in addition to current detection information, the subsequent process is put on hold (S13: NO). Note that the received information storage unit 31 may store not only current measurement information but also past measurement information.

[0065] In the correction process S20, the correction unit 28 acquires current detection information and past detection information (S21), corrects the point cloud information (S24), and determines whether there is any uncorrected point cloud information (S25). Note that step S21 may be processed after deleting past detection information that has been detected for a certain period of time or more.

[0066] If there is no uncorrected point cloud information (S25: YES), the point cloud information is output (S26). If there is no uncorrected point cloud information (S25: YES), step S24 is repeated to correct the point cloud information until there is no uncorrected point cloud information.

[0067] As shown by the dashed line in Figure 9, the correction assistance unit 29 may acquire current detection information and past detection information (S22), and associate the current detection information with the current measurement information or past measurement information whose measurement time is closest to the detection time of the current detection information (S23).

[0068] Note that step S22 may be performed after deleting past detection information for which a certain amount of time has elapsed since measurement. Specifically, the processing of step S23 is, for example, processing for rounding the time precision of the measurement information to 10 milliseconds to 100 milliseconds.

[0069] The correction method for correcting current detection information, which is current detection information of the detection target 2 obtained from the detection device 3, includes a first step (S12) of receiving the current detection information from the detection device 3 and storing the current detection information and past detection information, which is past current detection information, and a second step (S24) of comparing the past and present from the current detection information and multiple pieces of past detection information to calculate relative speed and relative distance, and correcting the current detection information to corrected detection information using the calculated relative distance.

[0070] As described above, the correction device 4 in this embodiment is a correction device 4 that corrects current detection information, which is current detection information of the detection target 2 obtained from the detection device 3, and includes a received information storage unit 31 that receives the current detection information from the detection device 3 and stores the current detection information and past detection information, which is past current detection information, and a correction unit 28 that compares the past and present from the current detection information and multiple pieces of past detection information to calculate the relative speed and relative distance 11, and corrects the current detection information to corrected detection information using the calculated relative distance 11.

[0071] This makes it possible to realize a correction device 4 that corrects the current detection information to corrected detection information that enables detection of the detection target 2 that cannot be detected by the current detection information, so that the detection target 2 can be detected with the high accuracy required for the vehicle 7 to travel safely.

[0072] When the past detection information is adjusted to fall within a predetermined range 71 by referring to a normal distribution 70 based on the current detection information, the correction device 4 does not need to refer to the past detection information, which is likely to have values ​​that are far from the current detection information. This makes it possible to realize a correction device 4 that corrects the past detection information to correct the past detection information so that the detection target 2 can be detected with higher accuracy than when the normal distribution 70 is not referred to.

[0073] The correction device 4 further acquires current measurement information of the vehicle 7 from the measurement device 8, the memory unit 27 stores the current measurement information and past measurement information that is past current measurement information, and the correction device 4 further includes a correction assistant unit 29.

[0074] The correction assisting unit 29 associates the current detection information with the current measurement information or the past measurement information whose measurement time is closest to the detection time of the current detection information. The correction assisting unit 29 corrects the current detection information to corrected detection information based on the associated current measurement information or the past measurement information whose measurement time is closest to the detection time of the current detection information.

[0075] This makes it possible to realize a correction device 4 that corrects the corrected detection information to make it possible to detect the target 2 that cannot be detected using the current detection information or the corrected detection information using the relative distance 11. This also makes it possible to extend the range in which the target 2 can be detected with a probability of about 60% based on the normalized portion 70, for example, beyond the time te (using information from further back in time).

[0076] In the above embodiment, the currently detected information and the currently measured information or the past measured information, which are asynchronous, are synchronized in time using time stamps, but the present invention is not limited to this.

[0077] For example, current detection information and current measurement information or past measurement information may be synchronized in terms of position using position information obtained by a Global Navigation Satellite System (GNSS) or the like that can be acquired by both the detection device 3 and the measurement device 8.

[0078] When the current detection information and the current measurement information or the past measurement information are synchronized in terms of position, the normal distribution 70 indicates the distribution of the probability that the vehicle 7 can detect the detection target 2 depending on its position, and the horizontal axis represents distance information rather than time information. [Explanation of symbols]

[0079] 1...Correction system, 2...Detection object, 3...Detection device, 4...Correction device, 5...Road, 6...Direction of travel, 7...Vehicle, 8...Measuring device, 9, 10...Scanning line, 11...Relative distance, 12...Shake, 13...Misalignment, 15...Presentation device, 20...Detection information acquisition unit, 21...Detection information transmission unit, 22...Central processing unit, 23...Main memory device, 24...Auxiliary memory device, 25...Communication device, 26...Control unit, 27...Memory unit, 28...Correction unit, 29...Correction auxiliary unit, 30...Presentation information control unit, 31...Received information memory unit, 32...Offset information memory unit, 33...Detection information receiving unit, 34...Measurement information receiving unit, 35...Presentation information transmission unit, 36...Measurement information acquisition unit, 37...Measurement information transmission unit, 38...Presentation information receiving unit, 39...Presentation unit.

Claims

1. A correction device that corrects current detection information, which is current detection information of a detection target acquired from a detection device, a received information storage unit that receives the current detection information from the detection device and stores the current detection information and past detection information that is the past current detection information; a correction unit that compares the current detection information and the plurality of pieces of past detection information to calculate a relative speed and a relative distance, and corrects the current detection information to corrected detection information using the calculated relative distance. Correction device.

2. The past detection information falls within a predetermined range in a normal distribution based on the current detection information. The correction device according to claim 1 .

3. The correction device further acquires current measurement information of the vehicle from the measurement device, and the storage unit stores the current measurement information and past measurement information, which is the past current measurement information; The correction device further includes a correction assisting unit that associates the current detection information with the current measurement information or the past measurement information whose measurement time is closest to the detection time of the current detection information, and corrects the current detection information to the corrected detection information based on the associated current measurement information or the past measurement information whose measurement time is closest to the detection time of the current detection information. The correction device according to claim 1 .

4. the correction unit corrects the current detection information detected from at least two or more of the detection targets to the corrected detection information, The correction device according to claim 1 .

5. transmitting information presenting the detection target detected by the current detection information and the detection target detected by the corrected detection information to a presentation device; The correction device according to claim 1 or 3.

6. A correction method for correcting current detection information, which is current detection information of a detection object obtained from a detection device, comprising: a first step of receiving the current detection information from the detection device and storing the current detection information and past detection information that is the past current detection information; a second step of comparing the current detection information and the plurality of pieces of past detection information to calculate a relative speed and a relative distance, and correcting the current detection information to corrected detection information using the calculated relative distance. Correction method.

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