Acoustic sensor and vehicle structure

Abstract

To provide an acoustic sensor capable of increasing detection precision of a sound vibration occurring near a tire.SOLUTION: An acoustic sensor 100 is mounted to a tire house cover 20 for covering an outer peripheral side GG of a tire TR in a vehicle Ve. The acoustic sensor 100 measures information related to a sound vibration. The acoustic sensor 100 comprises a sensor holding section 61, a sound collection surface section 41, and a sound vibration sensor 51. The sensor holding section 61 is held by a cover outer surface 23 facing the outer peripheral side GG from among both the surfaces of a cover body 21 that extends along a circumferential direction CH of the tire TR in the tire house cover 20. The sound collection surface section 41 opposes the cover outer surface 23 such that a sound vibration of the cover outer surface 23 is propagated by holding of the cover outer surface 23 by the sensor holding section 61. The sound vibration sensor 51 detects a sound vibration collected by the sound collection surface section 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE DISCLOSURE This disclosure relates to acoustic sensors and vehicle structures that include acoustic sensors. [Background technology]

[0002] Patent Document 1 discloses a road surface condition detection device equipped with a microphone. The microphone is attached to a vehicle in front of the tires. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-174543 Summary of the Invention [Problem to be solved by the invention]

[0004] A microphone located in front of the tire, as in Patent Document 1, is designed to collect sound in the air, making it difficult to effectively collect sound vibrations generated near the tire. In addition, there is a risk that other sound vibrations generated in a position other than near the tire may be transmitted to the microphone. For these reasons, it has been difficult to improve the accuracy of detecting sound vibrations generated near the tire.

[0005] The present disclosure aims to provide an acoustic sensor that can improve the accuracy of detecting sound vibrations generated near a tire, and a vehicle structure that includes this acoustic sensor. [Means for solving the problem]

[0006] In order to achieve the above object, one disclosed embodiment is an acoustic sensor that is attached to a cover member (20) that covers the outer peripheral side (GG) of a tire (TR) in a vehicle (Ve) and measures information related to sound vibrations, and that includes a sensor holding portion (61) that is held on the cover outer surface (23) that faces the outer peripheral side of the curved plate portion (21) that extends along the circumferential direction (CH) of the tire in the cover member, an opposing surface portion (41) that faces the cover outer surface so that sound vibrations from the cover outer surface are transmitted by holding the sensor holding portion on the cover outer surface, and a vibration detection portion (51) that detects sound vibrations collected by the opposing surface portion.

[0007] One disclosed embodiment is a vehicle structure having a curved plate portion (21) extending along the circumferential direction (CH) of a tire (TR) of a vehicle (Ve), a cover member (20) covering the outer peripheral side (GG) of the tire, and an acoustic sensor (100) attached to the cover member for measuring information related to sound vibrations, the acoustic sensor comprising a sensor holding portion (61) held on the cover outer surface (23) facing the outer peripheral side of the curved plate portion, an opposing surface portion (41) facing the cover outer surface so that sound vibrations from the cover outer surface are transmitted by holding the sensor holding portion on the cover outer surface, and a vibration detection portion (51) for detecting sound vibrations collected by the opposing surface portion.

[0008] In these embodiments, the acoustic sensor is attached to a cover member that covers the outer periphery of the tire, with the opposing surface facing the curved plate portion that extends along the circumferential direction of the tire. Therefore, the opposing surface can effectively collect sound vibrations generated near the tire by utilizing the curved surface portion that covers the tire. Additionally, because the opposing surface is oriented toward the tire, other sound vibrations generated at positions other than near the tire are less likely to be transmitted to the opposing surface. This makes it possible to improve the detection accuracy of sound vibrations generated near the tire.

[0009] It should be noted that the reference numbers in parentheses in the above and claims merely indicate an example of the correspondence with the specific configurations in the embodiments described below, and do not limit the technical scope in any way. Furthermore, claims not explicitly stated in the claims may be combined together if no particular problems arise in the combination. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a state in which an acoustic sensor and a vehicle structure according to a first embodiment of the present disclosure are mounted on a vehicle. [Figure 2] FIG. 10 is a diagram illustrating an acoustic sensor according to a comparative example. [Figure 3] 10A and 10B are diagrams for explaining the effect of an invisibly arranged acoustic sensor. [Figure 4] FIG. 10 is a diagram for explaining the effect of an acoustic sensor disposed in front, showing a scene where the water depth on the road surface is shallow. [Figure 5] FIG. 10 is a diagram for explaining the effect of an acoustic sensor disposed in front, showing a scene where deep water is present on the road surface. [Figure 6] FIG. 10 is a diagram showing a state in which an acoustic sensor and a vehicle structure according to a second embodiment are mounted on a vehicle. [Figure 7] FIG. 10 is a diagram showing a state in which an acoustic sensor and a vehicle structure according to a third embodiment are mounted on a vehicle. [Figure 8] FIG. 10 is a diagram showing a state in which an acoustic sensor and a vehicle structure according to a fourth embodiment are mounted on a vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments will be described with reference to the drawings. Note that corresponding components in each embodiment are given the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment described previously can be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can also be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0012] (First embodiment) An acoustic sensor 100 according to a first embodiment of the present disclosure is disposed near a tire TR in a vehicle Ve shown in Fig. 1. The acoustic sensor 100 measures information related to sound vibrations generated near the tire TR as the vehicle Ve travels. The acoustic sensor 100 is attached to a wheel well cover 20 that covers the tire TR. The acoustic sensor 100 and the wheel well cover 20 constitute a vehicle structure 10 that is mounted on the vehicle Ve.

[0013] The details of the configuration of the acoustic sensor 100, the details of the installation of the acoustic sensor 100, and the details of the signal processing ECU that processes the detection signal of the acoustic sensor 100 will be described below with reference to FIG.

[0014] Here, the longitudinal direction and the lateral direction in this disclosure are defined with respect to a vehicle Ve that is stationary on a horizontal plane. Specifically, the longitudinal direction (forward Ze and backward Go) is defined along the longitudinal direction of the vehicle Ve. The traveling direction SH of the vehicle Ve is the forward Ze. The lateral direction (right Mi and left) is defined along the width direction of the vehicle Ve. The vertical direction (upward Ue and downward Si) is defined along the vertical direction of the horizontal plane that defines the longitudinal direction and the lateral direction. Furthermore, the circumferential direction CH, inner side NG, and outer side GG are defined with respect to one tire TR. For simplicity of description, the symbols indicating the respective directions may be omitted as appropriate in the following description.

[0015] [Details of acoustic sensor configuration] The acoustic sensor 100 includes a sensor housing 40, a circuit board, a sound vibration sensor 51, and a retainer.

[0016] The sensor housing 40 has a flat rectangular prism or cylindrical shape as a whole. The sensor housing 40 is mainly made of a resin material. The internal space defined inside the sensor housing 40 contains a circuit board and a sound vibration sensor 51.

[0017] The sensor housing 40 has a sound collection surface 41. The sound collection surface 41 is formed by the bottom wall of the housing body. The sound collection surface 41 is at least a part of the outer surface of the bottom wall, and is formed as a flat surface. Sound vibrations measured by the sound vibration sensor 51 are input to the sound collection surface 41.

[0018] The circuit board is a glass epoxy board or the like, and has an overall rectangular plate shape. The circuit board is housed in the sensor housing 40 in a position that is aligned with the sound collection surface 41. The circuit board is provided with an amplifier circuit section, a communication interface, and the like. The amplifier circuit section is electrically connected to the sound vibration sensor 51, and amplifies the detection signal output by the sound vibration sensor 51. The communication interface outputs the detection signal amplified by the amplifier circuit section.

[0019] The sound vibration sensor 51 is a microphone element that converts air vibrations such as sound into an electric signal. The sound vibration sensor 51 is, for example, a condenser microphone mainly composed of a MEMS (Micro Electro Mechanical Systems) microphone. The sound vibration sensor 51 converts a change in capacitance that occurs when a thin diaphragm (membrane) vibrates due to sound pressure into an electric signal, and outputs this electric signal as a detection signal. The sound vibration sensor 51 is mounted on a circuit board, and detects sound vibrations that are collected by the sound collection surface 41 and transmitted to the diaphragm. The detection signal of the sound vibration sensor 51 can be output to an external component such as a signal processing ECU via a wire harness or the like.

[0020] The sound vibration sensor 51 may include a piezoelectric sensor as a microphone element instead of the MEMS microphone. The piezoelectric sensor measures the vibration of a metal plate vibrating membrane using a piezoelectric element formed in a thin plate shape. Furthermore, the sound vibration sensor 51 may include an electret condenser microphone as a microphone element instead of the MEMS microphone. In addition, the circuit board may further be provided with a signal processing circuit that processes the detection signal of the sound vibration sensor 51. The signal processing circuit is mainly composed of a microcontroller or the like. In such a configuration, the processing results generated by the signal processing circuit are output to an external in-vehicle ECU or the like via a wire harness or the like.

[0021] The retainer is made of a resin material and is formed into a flat cylindrical shape with a flange. The retainer is a member that holds the sensor housing 40 against the wheelhouse cover 20. The retainer has a sensor holding portion 61. The sensor holding portion 61 is a flange-shaped portion provided on the retainer. The sensor holding portion 61 is attached to the wheelhouse cover 20 by an adhesive layer, and is thereby held to the wheelhouse cover 20. The adhesive layer is made of double-sided tape, an adhesive material, or the like.

[0022] [Details of acoustic sensor installation] The acoustic sensor 100 is mounted on a vehicle Ve in a state where it is assembled to a tire house cover 20. The tire house cover 20 is made of lightweight and highly durable materials such as polyethylene resin and hard fibers made by blending polyester fibers with hard styrene-butadiene rubber. The tire house cover 20 is a molded product that has an overall curved plate shape.

[0023] The tire house cover 20 is arranged as a fender liner on the outer periphery GG of the tire TR and inside the fender FD. The tire house cover 20 is attached to the vehicle Ve so as to fill the gap between the fender FD and the tire TR. The tire house cover 20 prevents mud, spray, etc. kicked up from the road by the tire TR from entering the interior of the vehicle, thereby suppressing corrosion and damage to the vehicle body structure. The tire house cover 20 absorbs noise and vibrations generated when the vehicle Ve is traveling, improving quietness inside the vehicle.

[0024] The tire house cover 20 includes a cover body 21. The cover body 21 is the main body of the tire house cover 20. The cover body 21 has a curved plate shape extending along the circumferential direction CH of the tire TR. The radius of curvature of the arch-shaped cover body 21 is larger than the radius of the tire TR as a whole. Both sides of the cover body 21 are a cover inner surface 22 and a cover outer surface 23, respectively.

[0025] The cover inner surface 22 is one plate surface facing the inner circumferential side NG. The cover inner surface 22 is an exposed surface (front surface) that is exposed inside the tire house when the tire house cover 20 is attached to the vehicle Ve. The cover inner surface 22 faces the tread surface of the tire TR in the radial direction. A sound-absorbing material such as felt may be attached to the cover inner surface 22 to improve noise reduction.

[0026] The cover outer surface 23 is the other plate surface facing the outer circumferential side GG. When the tire house cover 20 is attached to the vehicle Ve, the cover outer surface 23 becomes the back surface facing the inside of the vehicle body. The cover outer surface 23 is not exposed on the tire TR side. An acoustic sensor 100 is attached to the cover outer surface 23. A guide portion is provided on the cover outer surface 23.

[0027] The guide portion protrudes from the cover outer surface 23 toward the outer circumferential side GG. The guide portion extends along the outer edge of the sensor holding portion 61 and is used to position the acoustic sensor 100. The guide portion is formed on the cover outer surface 23 of the front portion 26 of the cover main body 21. The front portion 26 is a portion of the cover main body 21 located forward Ze of the vehicle Ve (in the traveling direction SH) with respect to the tire TR. The front portion 26 is a range of the cover main body 21 located forward Ze of the front end TFe of the tread surface of the tire TR. The shape of the guide portion may be changed as appropriate as long as it can perform the positioning function of the acoustic sensor 100. The guide portion may be formed, for example, in a pin shape. Alternatively, a recess corresponding to the shape of the acoustic sensor 100 may be formed on the cover outer surface 23 as the guide portion. Furthermore, the guide portion does not have to be provided on the cover outer surface 23.

[0028] The acoustic sensor 100 is installed near one of the left and right front tires of the vehicle Ve. One acoustic sensor 100 may be installed near each of the left and right front tires. The acoustic sensor 100 is mounted on the vehicle Ve in an invisible arrangement that cannot be seen from outside the vehicle Ve. The acoustic sensor 100 is installed forward Ze of the tire TR with the sound collection surface 41 facing toward the tire TR (inner peripheral side NG) so as to more effectively measure the water pushing sound generated in front of the tire TR than the water splashing sound generated behind the tire TR.

[0029] More specifically, the sensor holding portion 61 is held on the cover outer surface 23, which faces the outer peripheral side GG, of both sides of the cover main body 21. The sensor holding portion 61 is attached to the cover outer surface 23 of the front portion 26 of the cover main body 21 in an orientation facing the inner peripheral side NG. The sensor holding portion 61 is positioned by a guide portion and attached to the cover outer surface 23 with an adhesive layer. By holding the sensor holding portion 61 on the cover outer surface 23, the sound collection surface 41 faces the cover outer surface 23 so that sound vibrations from the cover outer surface 23 are transmitted. The sound collection surface 41, like the sensor holding portion 61, is held on the cover outer surface 23 via an adhesive layer. The sound collection surface 41 is in indirect contact with the cover outer surface 23. This allows vibrations from the cover main body 21 to be efficiently transmitted to the sound collection surface 41.

[0030] Here, the state in which the sound collecting surface 41 is in indirect contact with the cover outer surface 23 means that there is no space between the sound collecting surface 41 and the cover outer surface 23, and both the sound collecting surface 41 and the cover outer surface 23 are in contact with both sides of a solid transmission member that transmits vibrations. The adhesive layer between the sound collecting surface 41 and the cover outer surface 23 may be omitted. In this form, the sound collecting surface 41 is pressed against the cover outer surface 23, and is in direct, rather than indirect, contact with the cover outer surface 23.

[0031] Furthermore, the acoustic sensor 100 does not need to include a configuration equivalent to a retainer. In such an acoustic sensor 100, the sound collection surface 41 also serves as the sensor holding portion 61. That is, the sound collection surface 41 and the sensor holding portion 61 may be integrally formed by the bottom wall portion of the housing main body.

[0032] [Signal Processing ECU Details] The signal processing ECU is a computing device mounted on the vehicle Ve. The signal processing ECU is electrically connected to the acoustic sensor 100 via a wire harness or the like. The signal processing ECU functions as a signal processing device that processes detection signals output by the acoustic sensor 100. In a vehicle Ve equipped with a plurality of acoustic sensors 100, the signal processing ECU acquires and processes detection signals from the plurality of acoustic sensors 100. The signal processing ECU may be an on-board ECU dedicated to acoustic recognition that processes detection signals from the acoustic sensors 100, or an on-board ECU dedicated to environmental recognition that recognizes the driving environment around the vehicle. Furthermore, the signal processing ECU may be an ADAS (Advanced Driver-Assistance Systems)-ECU capable of performing driving assistance control, or an autonomous driving ECU capable of performing autonomous driving control.

[0033] The signal processing ECU recognizes the state of the road surface on which the vehicle Ve is traveling based on the detection signal of the acoustic sensor 100. Specifically, the signal processing ECU determines whether the road surface on which the vehicle Ve is traveling is wet. Furthermore, if the signal processing ECU determines that the vehicle Ve is traveling on a wet road surface, it estimates the amount of water accumulated on the road surface on which the vehicle Ve is traveling, in other words, the road surface water level.

[0034] In addition to the road surface condition recognition process, the signal processing ECU may further execute a process for detecting the siren sound of an emergency vehicle approaching the vehicle Ve. Here, when using the detection signal of the acoustic sensor 100 mounted on the wheel well cover 20, the timing for detecting the siren sound of an approaching emergency vehicle is delayed compared to when using the detection signal of an acoustic sensor disposed on the rear window, etc. However, even when using the detection signal of the acoustic sensor 100 mounted on the wheel well cover 20, the signal processing ECU can detect the siren sound of an approaching emergency vehicle with a certain degree of distance and time leeway. In addition, the signal processing ECU may further execute a process for detecting impact sounds generated on the vehicle Ve. Impact sounds are sounds generated, for example, by tampering with or contact with the parked vehicle Ve. Such impact sound detection process can be utilized as a means for monitoring the parked vehicle Ve.

[0035] [Effects of invisible and forward placement of acoustic sensors] The acoustic sensor 100 described above is invisibly disposed in front of the tire TR Ze. The effect of this configuration in improving the accuracy of road surface water level estimation by the signal processing ECU will be described in detail below.

[0036] <Effects of invisible placement> The acoustic sensor 100z of the comparative example shown in FIG. 2 is attached to the cover inner surface 22 of the cover main body 21 with the sound collection surface 41z facing the tire TR side. The acoustic sensor 100z mainly collects sound vibrations in the space around the sensor using the sound collection surface 41z. The detection signal (sound data) output by such a visibly arranged acoustic sensor 100z makes it difficult to distinguish between sounds caused by water accumulating on the road surface (such as splashing sounds) and sounds caused by sand or the like on the road surface (such as sounds of sand and pebbles hitting the vehicle body). As a result, it becomes difficult to distinguish between the sounds of water and sand based on the sound data, and the signal processing ECU is unable to accurately determine whether water is present on the road surface, in other words, whether the road surface is wet.

[0037] It is also assumed that the acoustic sensor 100z is attached to the cover inner surface 22 with the sound collection surface 41z facing toward the cover inner surface 22. In the acoustic sensor 100z attached in this manner, the sound collection surface 41z faces away from the tire TR. Therefore, the sound collection surface 41z is more likely to collect other sound vibrations that reach the acoustic sensor 100z from the outer circumferential side GG of the tire TR, specifically, noise generated by a power source such as an engine and noise generated inside the vehicle cabin. As a result, the signal processing ECU is obstructed by the other sound vibrations and has difficulty detecting sound vibrations generated near the tire TR.

[0038] In contrast, the acoustic sensor 100 shown in FIG. 3 is attached to the cover outer surface 23 of the cover main body 21 with the sound collection surface 41 facing the tire TR. In this type of acoustic sensor 100 with a built-in tire cover, the tire house cover 20 is used to collect sound vibrations generated in the vicinity of the tire TR. The tire house cover 20 is shaped to cover the front Ze, upper Ue, and rear Go of the tire TR from the outer circumferential side GG. Due to this shape, the area of ​​the tire house cover 20 is larger than the area of ​​the sound collection surface 41. Therefore, by utilizing the tire house cover 20 that covers the outer circumferential side GG of the tire TR, the sound collection surface 41 can effectively collect sound vibrations generated in the vicinity of the tire TR.

[0039] In addition, the sound collection surface 41 faces the tire TR, making it difficult for it to collect other sound vibrations that arrive at the acoustic sensor 100 from the outer circumferential side GG of the tire TR. Therefore, the sound collection surface 41 can collect sound vibrations generated near the tire TR with priority over other sound vibrations. As a result, more information on sound vibrations near the tire is collected by the sound collection surface 41, improving the S / N ratio of the sound data. As a result, the signal processing ECU can more easily distinguish between the sound of water and the sound of sand, and can accurately determine whether the road surface is wet.

[0040] Furthermore, in the vehicle structure 10 in which the acoustic sensor 100 is invisibly arranged, water that accumulates on the road surface does not directly hit the acoustic sensor 100. Therefore, the design requirements related to waterproofing and water resistance of the acoustic sensor 100 can be relaxed compared to the acoustic sensor 100z (see FIG. 2) that is assumed to be arranged visible.

[0041] Furthermore, even when the vehicle Ve travels on a snowy road, ice does not adhere to the invisibly disposed acoustic sensor 100. Therefore, deterioration of the acoustic sensor 100 due to the adhesion of ice can be suppressed.

[0042] In addition, wind noise is less likely to be included in the detection signal of the invisibly placed acoustic sensor 100. Therefore, the acoustic sensor 100 can effectively measure the sound of water without being disturbed by wind noise.

[0043] Furthermore, with an invisibly placed acoustic sensor 100, it may be necessary to consider differences between vehicle types more than with a visibly placed acoustic sensor 100z (see FIG. 2). However, the frequency band of the sound of water is about 5 to 10 kHz, while the natural frequency of vibrations caused by the vehicle body and tires TR is a lower frequency band of about 300 to 800 Hz. Therefore, by considering the frequency band used for recognition, it is possible to accurately detect the sound of water while being less affected by differences between vehicle types.

[0044] <Effects of forward placement> 4 and 5, the water level on the road surface on which the vehicle Ve is traveling is different. In a driving scene where water has accumulated on the road surface, the sound of water generated behind the tire TR (Go) is mainly the sound of the tire TR splashing water. On the other hand, the sound of water generated in front of the tire TR (Ze) is mainly the sound of the tire TR pushing water out.

[0045] The water splash noise is unlikely to change even if the water level changes when the depth of water accumulating on the road surface exceeds a predetermined value (for example, about 1 cm). This is presumably because the amount of water splashed downstream of the tire TR does not substantially change when the water depth exceeds the predetermined value due to an upper limit on the drainage performance of the tire TR. On the other hand, the pushing noise changes depending on the water depth, even in areas where the depth of water accumulating on the road surface exceeds the above-mentioned predetermined value. This is presumably because the amount of water pushed out by the tire TR upstream of the tire TR continues to change as the water depth increases, without being affected by the drainage performance of the tire TR.

[0046] As described above, the acoustic sensor 100 disposed forward Ze of the tire TR mainly detects pushing noise rather than splashing noise as sound vibrations, which allows the signal processing ECU to more accurately estimate the depth (volume or level, etc.) of water accumulated on the road surface when the vehicle Ve is traveling on a wet road.

[0047] In addition, when the vehicle Ve travels on a snowy road, ice and the like are less likely to adhere to the cover inner surface 22 in front of the tire TR Ze than to the cover inner surface 22 in rear of the tire TR Go. Therefore, the effect of attenuation of sound vibrations due to adhesion to the cover inner surface 22 is also smaller for the acoustic sensor 100 located in front of the tire TR Ze.

[0048] (Summary of the first embodiment) In the first embodiment described so far, the acoustic sensor 100 is attached to the wheelhouse cover 20 that covers the outer circumferential side GG of the tire TR, with the sound collection surface 41 facing the cover main body 21 that extends along the circumferential direction CH of the tire TR. Therefore, the sound collection surface 41 can effectively collect sound vibrations generated in the vicinity of the tire TR by utilizing the cover main body 21 that is shaped to cover the tire TR. In addition, because the sound collection surface 41 is oriented toward the tire TR, other sound vibrations generated in positions other than the vicinity of the tire TR are less likely to be transmitted to the sound collection surface 41. As a result, it is possible to improve the detection accuracy of sound vibrations generated in the vicinity of the tire TR.

[0049] Additionally, the sound collecting surface 41 of the first embodiment is in indirect contact with the cover outer surface 23 due to the sensor holding portion 61 being held on the cover outer surface 23. Therefore, sound vibrations of the cover main body 21 can be efficiently transmitted to the sound collecting surface 41. As a result, the acoustic sensor 100 can accurately detect sound vibrations generated in the vicinity of the tire TR.

[0050] Furthermore, the sensor holding portion 61 of the first embodiment is held on the cover outer surface 23 of the front portion 26 of the cover main body 21, which is formed to be located in front of the vehicle Ve with respect to the tire TR. Therefore, the acoustic sensor 100 can effectively acquire the pushing sound of the tire TR pushing out water accumulated on the road surface. As a result, the accuracy of estimating the water level on the road surface can be improved.

[0051] In the above embodiment, the wheelhouse cover 20 corresponds to the "cover member", the cover main body 21 corresponds to the "curved plate portion", the sound collection surface portion 41 corresponds to the "opposing surface portion", the sound vibration sensor 51 corresponds to the "vibration detection portion", and the forward Ze corresponds to the "forward direction".

[0052] Second Embodiment A second embodiment of the present disclosure shown in FIG. 6 is a modified example of the first embodiment. In a vehicle structure 210 of the second embodiment, an acoustic sensor 100 is invisibly arranged rearward Go of a tire TR. In the acoustic sensor 100, a sensor holding portion 61 is attached to the cover outer surface 23 of a rear portion 27 of a cover main body 21. The rear portion 27 is a portion of the cover main body 21 that is located rearward Go of the vehicle Ve with respect to the tire TR (rearward direction). The rear portion 27 is a range of the cover main body 21 that is located rearward Go of the rear end TBe of the tread surface of the tire TR. A guide portion used for positioning the acoustic sensor 100 may be formed on the cover outer surface 23 of the rear portion 27.

[0053] In the vehicle structure 210 according to the second embodiment described above, the acoustic sensor 100 can also effectively collect sound vibrations generated in the vicinity of the tire TR by utilizing the cover main body 21 that covers the tire TR. Therefore, the second embodiment also achieves the same effects as the first embodiment, and can improve the detection accuracy of sound vibrations generated in the vicinity of the tire TR.

[0054] Additionally, the sensor holding portion 61 of the second embodiment is held on the cover outer surface 23 of the rear portion 27 of the cover main body 21, which is formed to be located rearward Go of the vehicle Ve with respect to the tire TR. Therefore, the acoustic sensor 100 can effectively acquire sound vibrations caused by the tire TR stirring up water accumulated on the road surface. As a result, it becomes possible to accurately determine whether the road surface is wet while traveling and to estimate the road surface water level below a predetermined value. In the second embodiment, the rearward Go corresponds to the "reverse direction."

[0055] (Third embodiment) A third embodiment of the present disclosure shown in FIG. 7 is another modified example of the first embodiment. In a vehicle structure 310 of the third embodiment, an acoustic sensor 100 is invisibly arranged above Ue of a tire TR. In the acoustic sensor 100, a sensor holding portion 61 is attached to the cover outer surface 23 of the central apex 28 of the cover main body 21. The central apex 28 is a portion of the cover main body 21 that is located above Ue of the vehicle Ve with respect to the tire TR. The central apex 28 is a range of the cover main body 21 that is located above Ue of the upper end TTe of the tread surface of the tire TR. A guide portion used for positioning the acoustic sensor 100 may be formed on the cover outer surface 23 of the central apex 28.

[0056] In the vehicle structure 310 according to the third embodiment described above, the acoustic sensor 100 can also effectively collect sound vibrations generated in the vicinity of the tire TR by utilizing the cover main body 21. Therefore, in the third embodiment, the same effects as in the first embodiment can be achieved, and the detection accuracy of sound vibrations generated in the vicinity of the tire TR can be improved.

[0057] Additionally, the sensor holder 61 of the third embodiment is held on the cover outer surface 23 of the central apex 28 of the cover body 21, which is formed so as to be positioned above the tire TR relative to the vehicle Ve. Therefore, the acoustic sensor 100 can acquire sound vibrations, including splashing noise and pushing noise, by measuring them. As a result, it is possible to determine whether the road surface is wet while the vehicle is traveling and estimate the road surface water level with relatively high accuracy. Furthermore, even in a vehicle Ve where the acoustic sensor 100 cannot be placed inside the front portion 26 and the rear portion 27, it is possible to place the acoustic sensor 100 inside the wheel well cover 20 as long as space can be secured above the central apex 28. In the second embodiment, the central apex 28 corresponds to the "upper portion," and the upper portion Ue corresponds to the "upward direction."

[0058] (Fourth embodiment) 8 is yet another modified example of the first embodiment. A vehicle structure 410 of the fourth embodiment includes a plurality of (two) acoustic sensors 100 in addition to a wheel well cover 20. The vehicle structure 410 includes at least a first acoustic sensor 110 and a second acoustic sensor 120 as the plurality of acoustic sensors 100.

[0059] The first acoustic sensor 110 is invisibly disposed in front of the tire TR, Ze. The sensor holding portion 61 of the first acoustic sensor 110 is attached to the cover outer surface 23 of the front portion 26 of the cover main body 21. The second acoustic sensor 120 is invisibly disposed behind the tire TR, Go. The sensor holding portion 61 of the second acoustic sensor 120 is attached to the cover outer surface 23 of the rear portion 27 of the cover main body 21.

[0060] The first acoustic sensor 110 and the second acoustic sensor 120 may be installed at approximately the same height in the vertical direction, or may be installed at different heights. For example, the first acoustic sensor 110 may be installed at a higher position than the second acoustic sensor 120, or may be installed at a lower position than the second acoustic sensor 120. Furthermore, the first acoustic sensor 110 and the second acoustic sensor 120 may be arranged without any left-right offset in the width direction, or may be arranged with a left-right offset.

[0061] In the vehicle structure 410 according to the fourth embodiment described above, the two acoustic sensors 100 can also effectively collect sound vibrations generated in the vicinity of the tire TR by utilizing the cover main body 21. Therefore, the fourth embodiment also achieves the same effects as the first embodiment, and can improve the detection accuracy of sound vibrations generated in the vicinity of the tire TR.

[0062] Additionally, the vehicle structure 410 of the fourth embodiment includes at least a first acoustic sensor 110 and a second acoustic sensor 120 as the multiple acoustic sensors 100. The sensor holding portion 61 of the first acoustic sensor 110 is held on the cover outer surface 23 of the front portion 26 of the cover main body 21, which is formed to be located in front of the vehicle Ve with respect to the tire TR. Meanwhile, the sensor holding portion 61 of the second acoustic sensor 120 is held on the cover outer surface 23 of the rear portion 27 of the cover main body 21, which is formed to be located in rear of the vehicle Ve with respect to the tire TR. With the above configuration, the first acoustic sensor 110 and the second acoustic sensor 120 can acquire sound vibrations generated near the tire TR at different positions. Therefore, by combining the detection signals (sound data) of the first acoustic sensor 110 and the second acoustic sensor 120, more precise water volume determination is possible.

[0063] (Other embodiments) Although multiple embodiments of the present disclosure have been described above, the present disclosure should not be construed as being limited to the above-described embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0064] The mounting position of the acoustic sensor 100 in the width direction of the vehicle Ve may be changed as appropriate. For example, in Modification 1 of the above embodiment, the acoustic sensor 100 is mounted outside the center of the cover body 21. In Modification 1, the acoustic sensor 100 is located away from the power source and the vehicle interior space. As a result, noise generated in the vehicle Ve, such as noise generated by the power source and noise generated inside the vehicle interior, is less likely to be included in the detection signal acquired by the acoustic sensor 100.

[0065] In addition, in Modification 2 of the above embodiment, the acoustic sensor 100 is attached to the central portion of the cover main body 21 in the width direction. In other words, the acoustic sensor 100 is installed at a position facing the central portion of the tread surface of the tire TR. In Modification 2, the acoustic sensor 100 is installed at a position where water splashed up by the tire TR is likely to hit the acoustic sensor 100, making it easy to measure the water splashing sound and the pushing sound.

[0066] Furthermore, the mounting position of the acoustic sensor 100 in the vertical direction of the vehicle Ve may also be changed as appropriate. When the vehicle Ve is empty, the acoustic sensor 100 may be installed above the wheel center Ue of the tire TR, or below the wheel center Si.

[0067] In Modification 3 of the above embodiment, the acoustic sensor 100 is installed near one of the left and right rear tires of the vehicle Ve. Also, in Modification 4 of the above embodiment, the acoustic sensor 100 is installed near each of the left rear tire and the right rear tire. Furthermore, in Modification 5 of the above embodiment, the acoustic sensor 100 is installed near all of the tires TR. As in Modifications 3 to 5 above, the number and installation positions of the acoustic sensors 100 may be changed as appropriate.

[0068] The vehicle structure according to the sixth modification of the fourth embodiment is provided with three acoustic sensors 100. In addition to the first acoustic sensor 110 provided in the front portion 26 and the second acoustic sensor 120 provided in the rear portion 27, the vehicle structure also includes a third acoustic sensor provided in the central top portion 28.

[0069] In a seventh modification of the fourth embodiment, the first acoustic sensor 110 and the second acoustic sensor 120 are both attached to the cover outer surface 23 of the front portion 26. The first acoustic sensor 110 and the second acoustic sensor 120 are arranged at positions offset from each other in at least one of the circumferential direction CH and the axial direction of the tire TR. As in this seventh modification, the arrangement of the multiple acoustic sensors 100 attached to one tire house cover 20 may be changed as appropriate.

[0070] In the eighth modification of the above embodiment, the sound collection surface 41 faces the cover outer surface 23 without contacting the cover outer surface 23, as the sensor holding portion 61 is held on the cover outer surface 23. A space is formed between the sound collection surface 41 and the cover outer surface 23. As in this eighth modification, the sound collection surface 41 does not need to be in contact with the cover outer surface 23, as long as sound vibrations of the cover main body 21 can be collected.

[0071] In a ninth modification of the above embodiment, a single acoustic sensor 100 incorporates multiple (two) sound vibration sensors 51. According to the acoustic sensor 100 of the ninth modification, sound vibrations occurring in the vicinity of the tire TR can be detected using the multiple sound vibration sensors 51. Therefore, by combining the detection signals (sound data) of the respective sound vibration sensors 51, more precise determination of the water volume becomes possible.

[0072] The vehicle Ve equipped with the vehicle structure 10 and the acoustic sensor 100 is not limited to a general private four-wheeled passenger vehicle. The vehicle structure 10 and the acoustic sensor 100 may be equipped on various vehicles, such as motorcycles, unmanned vehicles for mobility services, construction vehicles, agricultural vehicles, railroad vehicles, trams, and DMVs (Dual Mode Vehicles), and used to recognize sound data. In addition, the number and positions of the acoustic sensors 100 may be optimized as appropriate depending on the form of the vehicle Ve, the purpose of the vehicle Ve, and the traffic environment and laws and regulations of the country or region in which the vehicle Ve is used.

[0073] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with the subsequent clause referring to the preceding clause as an alternative. Furthermore, some clauses may be written in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0074] (Technical thought 1) a cover member (20) having a curved plate portion (21) extending along a circumferential direction (CH) of a tire (TR) of a vehicle (Ve), and covering an outer peripheral side (GG) of the tire; an acoustic sensor (100) attached to the cover member for measuring information related to sound vibrations; Including, The acoustic sensor includes: a sensor holding portion (61) held on the cover outer surface (23) facing the outer periphery of both surfaces of the curved plate portion; an opposing surface portion (41) facing the outer surface of the cover so that the sound vibration of the outer surface of the cover is transmitted by holding the sensor holding portion on the outer surface of the cover; a vibration detection unit (51) that detects the sound vibration collected by the opposing surface portion; A vehicle structure comprising: (Technical thought 2) The vehicle structure described in Technical Idea 1, wherein the sensor holding portion is held on the outer surface of the cover of the front portion (26) of the curved plate portion that is formed to be positioned in the forward direction (Ze) of the vehicle relative to the tire. (Technical Thought 3) The vehicle structure described in Technical Idea 1, wherein the sensor holding portion is held on the outer surface of the cover of a rear portion (27) of the curved plate portion that is formed to be positioned in the backward direction (Go) of the vehicle relative to the tire. (Technical Thought 4) The vehicle structure described in Technical Idea 1, wherein the sensor holding portion is held on the outer surface of the cover of the upper portion (28) of the curved plate portion that is formed to be positioned upward (Ue) of the vehicle relative to the tire. (Technical Thought 5) The plurality of acoustic sensors include at least a first acoustic sensor (110) and a second acoustic sensor (120), the sensor holding portion of the first acoustic sensor is held on the cover outer surface of a front portion (26) of the curved plate portion that is formed to be positioned in the forward direction (Ze) of the vehicle with respect to the tire, The vehicle structure described in Technical Idea 1, wherein the sensor holding portion of the second acoustic sensor is held on the outer surface of the cover of a rear portion (27) of the curved plate portion that is formed to be positioned in the backward direction (Go) of the vehicle relative to the tire. (Technical Thought 6) The vehicle structure according to any one of Technical Ideas 1 to 5, wherein the opposing surface portion comes into direct or indirect contact with the outer surface of the cover by the sensor holding portion being held on the outer surface of the cover. [Explanation of symbols]

[0075] CH circumferential direction, GG outer circumferential side, Go rearward (reverse direction), TR tire, Ue upper (upward direction), Ve vehicle, Ze forward (forward direction), 10, 210, 310, 410 vehicle structure, 20 tire house cover (cover member), 21 cover main body (curved plate portion), 23 cover outer surface, 26 front portion, 27 rear portion, 28 central top portion (upper portion), 41 sound collection surface portion (opposing surface portion), 51 sound vibration sensor (vibration detection portion), 61 sensor holding portion, 100 acoustic sensor, 110 first acoustic sensor, 120 second acoustic sensor

Claims

1. An acoustic sensor attached to a cover member (20) that covers an outer peripheral side (GG) of a tire (TR) in a vehicle (Ve) and measures information related to sound vibrations, a sensor holding portion (61) held on a cover outer surface (23) facing the outer periphery of both surfaces of a curved plate portion (21) extending along the circumferential direction (CH) of the tire in the cover member; an opposing surface portion (41) facing the outer surface of the cover so that the sound vibration of the outer surface of the cover is transmitted by holding the sensor holding portion on the outer surface of the cover; a vibration detection unit (51) that detects the sound vibration collected by the opposing surface portion; An acoustic sensor comprising:

2. The acoustic sensor according to claim 1 , wherein the facing surface portion is in direct or indirect contact with the outer surface of the cover when the sensor holding portion is held on the outer surface of the cover.

3. a cover member (20) having a curved plate portion (21) extending along a circumferential direction (CH) of a tire (TR) of a vehicle (Ve), and covering an outer peripheral side (GG) of the tire; an acoustic sensor (100) attached to the cover member and measuring information related to sound vibrations; Including, The acoustic sensor includes: a sensor holding portion (61) held on the cover outer surface (23) facing the outer periphery of both surfaces of the curved plate portion; an opposing surface portion (41) facing the outer surface of the cover so that the sound vibration of the outer surface of the cover is transmitted by holding the sensor holding portion on the outer surface of the cover; a vibration detection unit (51) that detects the sound vibration collected by the opposing surface portion; A vehicle structure comprising:

4. 4. The vehicle structure according to claim 3, wherein the sensor holding portion is held on the outer surface of the cover of a front portion (26) of the curved plate portion that is formed to be positioned in the forward direction (Ze) of the vehicle relative to the tire.

5. 4. The vehicle structure according to claim 3, wherein the sensor holding portion is held on the outer surface of the cover of a rear portion (27) of the curved plate portion that is formed to be positioned in the backward direction (Go) of the vehicle relative to the tire.

6. The vehicle structure according to claim 3, wherein the sensor holding portion is held on the outer surface of the cover of an upper portion (28) of the curved plate portion that is formed to be positioned upward (Ue) of the vehicle relative to the tire.

7. The plurality of acoustic sensors include at least a first acoustic sensor (110) and a second acoustic sensor (120), The sensor holding portion of the first acoustic sensor is held on the cover outer surface of a front portion (26) of the curved plate portion that is formed to be positioned in the forward direction (Ze) of the vehicle with respect to the tire, 4. The vehicle structure according to claim 3, wherein the sensor holding portion of the second acoustic sensor is held on the cover outer surface of a rear portion (27) of the curved plate portion that is formed to be positioned in a backward direction (Go) of the vehicle relative to the tire.

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