Evaluation device

Abstract

To provide an evaluation device that can evaluate wrong recognition due to reflection of a radar inside of a bumper beforehand.SOLUTION: An evaluation device evaluates a risk that a radar device arranged inside bumpers 12 and 14 of a vehicle 10 would wrongly recognize a detection object, and comprises: an acquisition unit 102a that acquires radio wave intensity in response to a distance from the radar device on the basis of a differential between a transmission radio wave of the radar device and a reception radio wave of a reflection wave of the transmission wave for respective cases when reinforcements 30 and 32 are present in the bumpers 12 and 14 of the vehicle 10, or not; a comparison unit 102b that compares the radio wave intensity when the reinforcements 30 and 32 are present in the bumpers 12 and 14, and not, and determines whether a difference more than a prescribed value stands; and a determination unit 102c that, when the difference more than the prescribed value in the radio wave intensity when the reinforcements 30 and 32 are present or not stands, determines that there is a risk of wrongly recognizing an object of the vehicle due to reflection of the transmission radio wave inside of the bumpers 12 and 14.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an evaluation device.

Background Art

[0002] Conventionally, it has been known to prevent false detection caused by a part of the transmission wave of a radar device being reflected on the back surface of a bumper by an anti-reflection structure (received wave diffusion structure) that prevents false reflection in a cover member (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to the technique described in Patent Document 1 above, there is a possibility that an anti-reflection structure may be provided even when there is no risk of false detection caused by reflection on the back surface of the bumper. In such a case, there is a problem that the anti-reflection structure becomes useless.

[0005] In addition, when the transmission radio wave is internally reflected within the bumper, it is necessary to take measures to prevent the transmission radio wave from propagating in components within the bumper such as reinforcements. If this measure is taken in the latter stage of the vehicle development period, it will cause a great impact such as a change in the manufacturing process. And currently, there is no effective method for predicting whether there is a risk of internal reflection at an early stage of the vehicle development period.

[0006] Therefore, an object of the present invention is to provide an evaluation device capable of preliminarily evaluating misrecognition of a detection target due to reflection of a radar inside a bumper.

Means for Solving the Problems

[0007] The gist of the present disclosure is as follows.

[0008] (1) An evaluation device that evaluates the risk of a radar device disposed in a bumper of a vehicle misrecognizing a detection target, an acquisition unit that acquires radio wave intensity corresponding to the distance from the radar device based on the difference between the transmitted radio wave of the radar device and the received radio wave of the reflected wave of the transmitted radio wave for each of the cases where there is a reinforcement in the bumper of the vehicle and where there is no reinforcement; a comparison unit that compares the radio wave intensities in the case where there is the reinforcement in the bumper and the case where there is no reinforcement, and determines whether there is a difference equal to or greater than a predetermined value; a determination unit that, based on the result of the comparison, determines that there is a risk of misrecognizing a detection target due to reflection of the transmitted radio wave inside the bumper when there is a difference equal to or greater than the predetermined value between the radio wave intensities in the case where there is the reinforcement and the case where there is no reinforcement, and determines that there is no risk of misrecognizing a detection target due to reflection of the transmitted radio wave inside the bumper when there is no difference equal to or greater than the predetermined value; An evaluation device comprising the above.

Effect of the Invention

[0009] According to the present invention, there is provided an evaluation device capable of preliminarily evaluating the misrecognition of a detection target due to reflection of radar inside a bumper.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] Hereinafter, several embodiments according to the present invention will be described with reference to the drawings. However, these descriptions are merely intended as examples of preferred embodiments of the present invention and are not intended to limit the present invention to such specific embodiments.

[0012] FIG. 1 is a diagram schematically showing the state of the vehicle 10 as viewed from above. Bumpers 12 and 14 are provided at the front and rear of the vehicle 10, respectively. A radar device is provided inside the bumpers 12 and 14. Specifically, radar sensors 20 and 22 are built into the left and right sides of the bumper 12, respectively. Similarly, radar sensors 24 and 26 are built into the left and right sides of the bumper 14, respectively.

[0013] The radio waves (millimeter waves) radiated from each radar sensor toward the outside of the vehicle 10 are reflected by a detection target (person, motorcycle, other vehicle, etc.) outside the vehicle 10 and received by each radar sensor. Taking the radar sensor 20 as an example, the radio waves radiated from the radar sensor 20 pass through the resin bumper 12 and are radiated to the outside of the vehicle 10. Then, the reflected wave reflected by the detection target outside the vehicle 10 is received by the radar sensor 20. And the position of the detection target relative to the vehicle 10 is acquired based on the received reflected wave.

[0014] Reinforces 30 and 32 are provided inside the bumpers 12 and 14, respectively. The reinforces 30 and 32 extend in the vehicle width direction inside the bumpers 12 and 14, respectively, and play a role of protecting the body skeleton and the occupants from front and rear collisions.

[0015] The radio waves radiated from each radar sensor toward the outside of the vehicle 10 may be reflected on the back surface of the bumper 12 or the bumper 14, propagate through the components inside the bumpers 12, 14, and the reflected waves may be received by each radar sensor. In FIG. 1, the radio waves radiated from the right front radar sensor 20 of the vehicle 10 are reflected on the right back surface of the bumper 12, propagate along the reinforcement 30 to the left side of the vehicle 10, and are further reflected on the left back surface of the bumper 12 and reflected by the left radar sensor 22 (dashed arrow). The radio waves reflected by the left radar sensor 22 return along the same path, are reflected on the right back surface of the bumper 12, and are received by the right front radar sensor 20 (dash-dotted arrow).

[0016] Similarly, in FIG. 1, the radio waves radiated from the right rear radar sensor 24 of the vehicle 10 are reflected on the right back surface of the bumper 14, propagate along the reinforcement 32 to the left side of the vehicle 10, and are further reflected on the left back surface of the bumper 14 and reflected by the left front radar sensor 26 (dashed arrow). The radio waves reflected by the left radar sensor 26 return along the same path, are reflected on the right back surface of the bumper 14, and are received by the right rear radar sensor 24 (dash-dotted arrow).

[0017] When the reflection of radio waves occurs on the back surface of the bumper 12 or the bumper 14 as described above, it may be erroneously recognized that there is a detection target outside the vehicle 10. In the example of the front bumper 12 of the vehicle 10 in FIG. 1, it is possible that a pseudo target 40 is erroneously recognized to exist at a position separated from the right radar sensor 20 by the total distance of the paths of the dashed arrow and the dash-dotted arrow. Similarly, in the example of the rear bumper 14 of the vehicle 10 in FIG. 1, it is possible that a pseudo target 42 is erroneously recognized to exist at a position separated from the right radar sensor 24 by the total distance of the paths of the dashed arrow and the dash-dotted arrow.

[0018] In particular, when the reinforcements 30 and 32 are provided inside the bumpers 12 and 14, radio waves are likely to propagate along the reinforcements 30 and 32 inside the bumpers 12 and 14, and there is a possibility of misrecognition that the pseudo targets 40 and 42 exist. When the reinforcements 30 and 32 are composed of hollow members, radio waves are more likely to propagate through the hollow interior, and the possibility of misrecognition becomes higher.

[0019] In this embodiment, focusing on the fact that the reinforcements 30 and 32 are the main factors as the radio wave propagation paths inside the bumpers 12 and 14, the radio wave intensities with and without the reinforcements 30 and 32 are compared. As a result of the comparison, if there is a difference in the radio wave intensity of a predetermined value or more, since there is a possibility of misrecognition due to reflection on the back surface of the bumpers 12 and 14, countermeasures are taken.

[0020] FIG. 2 is a schematic configuration diagram of an evaluation system 1000 according to one embodiment. The evaluation system 1000 includes a notification device 50 and an evaluation device 100.

[0021] As shown in FIG. 2, the evaluation device 100 includes a processor 102, a memory 104, and a communication interface 106. The processor 102 includes one or more CPUs (Central Processing Units) and peripheral circuits thereof. The processor 102 may further include other arithmetic circuits such as a logical arithmetic unit, a numerical arithmetic unit, or a graphic processing unit. The memory 104 includes, for example, a volatile semiconductor memory and a non-volatile semiconductor memory, and stores data related to the processing according to the present embodiment as necessary. The communication interface 106 includes an interface circuit for connecting the evaluation device 100 to the notification device 50 or an external network (such as the Internet).

[0022] The notification device 50 includes a display device and a speaker. The display device is composed of, for example, a liquid crystal display (LCD), and in response to an instruction from the evaluation device 100, it displays and notifies countermeasures for suppressing reflection inside the bumpers 12, 14. The speaker audibly notifies countermeasures in response to an instruction from the evaluation device 100.

[0023] FIG. 3 is a schematic diagram showing the functional blocks of the processor 102 of the evaluation device 100. The processor 102 has an acquisition unit 102a, a comparison unit 102b, a determination unit 102c, and a notification unit 102d. Each of these units of the processor 102 is a functional module realized by, for example, a computer program operating on the processor 102. That is, the functional blocks of the processor 102 are composed of the processor 102 and a program (software) for operating it. Further, the program may be recorded in the memory 104 provided in the evaluation device 100 or a recording medium connected externally. Alternatively, each of these units of the processor 102 may be a dedicated arithmetic circuit provided in the processor 102.

[0024] The acquisition unit 102a of the processor 102 acquires the radio wave intensity corresponding to the distance from the radar device based on the difference between the transmitted radio wave of the radar device (radar sensors 20, 22, 24, 26) and the received radio wave of the reflected wave of the transmitted radio wave, for each case where there are reinforcements 30, 32 in the bumpers 12, 14 and where there are no reinforcements. Specifically, the acquisition unit 102a obtains the distribution of the transmitted radio wave and the reflected wave of the transmitted radio wave for each case where there are reinforcements 30, 32 and where there are no reinforcements, based on the radar analysis model of the radar device, the post-processing calculation tool, and the CAD data representing the internal structure of the bumpers 12, 14, post-processes the difference between the transmitted radio wave and the received radio wave to decompose the radio wave intensity by distance, and acquires the radio wave intensity corresponding to the distance from the radar device.

[0025] Here, the radar analysis model is a model representing the distribution of transmitted radio waves radiated from the radar device, which is determined from the specifications of the radar device. The post-processing calculation tool is a tool that post-processes the difference between the transmitted radio wave and the received radio wave to decompose the radio wave intensity by distance. The CAD data is data representing the internal structures of the bumpers 12 and 14. When acquiring the radio wave intensity in the case where there are the reinforcements 30 and 32, the CAD data with the reinforcements 30 and 32 in the bumpers 12 and 14 is used. On the other hand, when acquiring the radio wave intensity in the case where there are no reinforcements 30 and 32, the CAD data without the reinforcements 30 and 32 in the bumpers 12 and 14 is used.

[0026] FIG. 4 is a diagram showing the characteristics of the radio wave intensity (power) according to the distance from the vehicle 10 for the radar sensor 20 at the right front of the bumper 12 on the front side of the vehicle 10, for each of the cases where there is and is not the reinforcement 30, acquired by the acquisition unit 102a. In FIG. 4, the characteristic indicated by the solid line shows the radio wave intensity in the case where there is the reinforcement 30. Also, the characteristic indicated by the broken line shows the radio wave intensity in the case where there is no reinforcement 30. FIG. 4 shows the characteristics when there is no detection target outside the vehicle 10. As shown in the characteristic of the broken line, when there is no detection target outside the vehicle 10 and there is no reinforcement 30, the radio wave intensity decreases as the distance from the vehicle 10 increases. When there is the reinforcement 30, if reflection occurs on the back surface of the bumper 12 as described with reference to FIG. 1, a peak in the radio wave intensity occurs at a predetermined distance shown in FIG. 4, and a deviation in the radio wave intensity occurs between the case where there is the reinforcement 30 and the case where there is no reinforcement 30 as indicated by the thick arrow. Therefore, when there is the reinforcement 30, there is a possibility of misrecognizing that there is some detection target at a position at a predetermined distance outside the vehicle 10.

[0027] The comparison unit 102b of the processor 102 compares the radio wave intensities in the cases where there are and are not the reinforcements 30 and 32, acquired by the acquisition unit 102a, and determines whether there is a difference of a predetermined value or more.

[0028] Based on the result of the comparison by the comparison unit 102b, the determination unit 102c of the processor 102 determines that there is a risk of misidentifying the detection target due to the reflection of the transmission radio wave inside the bumpers 12 and 14 when there is a difference of a predetermined value or more in the radio wave intensity between the case where the reinforcements 30 and 32 are present and the case where they are not present, and determines that there is no risk of misidentifying the detection target due to the reflection of the transmission radio wave inside the bumpers 12 and 14 when there is no difference of a predetermined value or more.

[0029] When it is determined that there is a risk of misidentifying the detection target due to the reflection of the transmission radio wave inside the bumpers 12 and 14, the notification unit 102d of the processor 152 notifies countermeasures for suppressing the risk of misidentification. Specifically, the notification unit 102d notifies, via the notification device 50, countermeasures such as changing the arrangement or shape of the reinforcements 30 and 32, closing the end face when the reinforcements 30 and 32 are hollow members, and changing the position of the radar device.

[0030] FIG. 5 is a flowchart showing the processing performed by the processor 102 of the evaluation device 100 at each predetermined control cycle. First, the acquisition unit 102a post-processes the difference between the transmission radio wave of the radar device and the received radio wave of the reflected wave of the transmission radio wave to obtain the radio wave intensity for the case where the reinforcements 30 and 32 are not present (step S10). Next, the acquisition unit 102a post-processes the difference between the transmission radio wave of the radar device and the received radio wave of the reflected wave of the transmission radio wave to obtain the radio wave intensity for the case where the reinforcements 30 and 32 are present (step S12). Next, the comparison unit 102b compares the radio wave intensities for the case where the reinforcements 30 and 32 are present and the case where they are not present, and determines whether there is a difference of a predetermined value or more (step S14).

[0031] In step S14, when there is no difference greater than or equal to a predetermined value in the radio wave intensity between the case where the reinforcements 30 and 32 are present and the case where they are not present, the determination unit 102c determines that there is no risk of misidentifying the detection target due to the reflection of the transmitted radio wave inside the bumpers 12 and 14 (step 16). On the other hand, in step S14, when there is a difference greater than or equal to a predetermined value in the radio wave intensity between the case where the reinforcements 30 and 32 are present and the case where they are not present, the determination unit 102c determines that there is a risk of misidentifying the detection target due to the reflection of the transmitted radio wave inside the bumpers 12 and 14 (step 18). After step 18, the notification unit 102d notifies the notification device 50 of the measures to suppress the reflection (step 20).

[0032] As described above, according to the present embodiment, since the propagation path of the internal reflection of the bumper that causes misidentification of the detection target is mainly caused by the reinforcement, based on the difference in radio wave intensity due to the presence or absence of the reinforcement, the risk of misidentifying the detection target due to the reflection of the transmitted radio wave inside the bumper can be accurately determined.

Explanation of Reference Numerals

[0033] 12, 14 Bumpers 20, 22, 24, 26 Radar Sensors 30, 32 Reinforcements 32 Reinforcement 40, 42 Pseudo-Targets 50 Notification Device 100 Evaluation Device 102 Processor 102a Acquisition Unit 102b Comparison Unit 102c Determination Unit 102d Notification Unit [[ID=CO35]]104 Memory 106 Communication Interface 1000 Evaluation System

Claims

Claim 1 An evaluation device that evaluates the risk of a radar device disposed within a bumper of a vehicle misidentifying a detection target, an acquisition unit that acquires radio wave intensity corresponding to the distance from the radar device based on the difference between the transmitted radio wave of the radar device and the received radio wave of the reflected wave of the transmitted radio wave, for each of the cases where there is and is not a reinforcement within the bumper of the vehicle; a comparison unit that compares the radio wave intensities for the cases where there is and is not the reinforcement within the bumper and determines whether there is a difference of a predetermined value or more; a determination unit that, based on the result of the comparison, determines that there is a risk of misidentifying a detection target due to reflection of the transmitted radio wave inside the bumper when there is a difference of a predetermined value or more between the radio wave intensities for the cases where there is and is not the reinforcement, and determines that there is no risk of misidentifying a detection target due to reflection of the transmitted radio wave inside the bumper when there is no difference of the predetermined value or more; An evaluation device comprising the above.

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