Ride comfort improvement device, vehicle, and ride comfort improvement method

Abstract

To provide a ride comfort improvement device, a vehicle, and a ride comfort improvement method capable of improving the ride comfort of a vehicle over a wide frequency band without relying on active suspension, sound insulation materials, or vibration-proofing materials.SOLUTION: A ride comfort improvement device according to an embodiment of the present disclosure generates a control signal capable of generating a second air vibration that reaches the head of a vehicle occupant at a predetermined timing before the occurrence of a first air vibration at the head of the vehicle occupant, on the basis of the detection or prediction results of an impact that occurs to a tire or knuckle while the vehicle is traveling, and outputs the generated control signal to a vibration generating device, thereby causing the vibration generating device to generate the second air vibration.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a ride comfort improvement device, a vehicle, and a ride comfort improvement method. [Background technology]

[0002] Conventionally, in order to improve the ride comfort of a vehicle, vibrations applied to occupants have been reduced by adjusting the suspension and seat materials. Additionally, conventionally, noises such as creaking that occur when the vehicle vibrates have been reduced by adding sound-insulating materials and vibration-damping materials.

[0003] For example, Patent Document 1 discloses that the driving sensation that a driver receives from vehicle response to inputs and changes in vehicle behavior due to changes in the driving environment is adjusted according to the driver's driving orientation and the driving environment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5573530 Summary of the Invention

[0005] A ride comfort improvement device according to a first aspect of the present disclosure includes an acquisition unit and a signal generation unit. The acquisition unit is capable of acquiring detection results or prediction results of an impact occurring in a tire or a knuckle while the vehicle is traveling. The signal generation unit is capable of generating a control signal based on the detection results or prediction results acquired by the acquisition unit and outputting the generated control signal to a vibration generating device. Here, the impact propagates to the head of a vehicle occupant, causing the head to vibrate, and the resulting air vibrations generated relative to the head are referred to as first air vibrations. At this time, the signal generation unit generates a control signal based on the detection results or prediction results, capable of generating second air vibrations that reach the head at a predetermined timing before the generation of the first air vibrations, and outputs the generated control signal to the vibration generating device, thereby causing the vibration generating device to generate the second air vibrations.

[0006] A vehicle according to a second aspect of the present disclosure is a vehicle equipped with a ride comfort improvement device and a vibration generating device. The ride comfort improvement device has a sensor and a signal generating unit. The sensor is capable of detecting an impact occurring in a tire or a knuckle while the vehicle is traveling. The signal generating unit is capable of generating a control signal based on the impact detection result of the sensor and outputting the generated control signal to the vibration generating device. Here, the impact propagates to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibrations generated relative to the head are referred to as first air vibrations. At this time, the signal generating unit is capable of generating a control signal capable of generating second air vibrations that reach the head at a predetermined timing before the generation of the first air vibrations, based on the impact detection result of the sensor, and outputting the generated control signal to the vibration generating device. The vibration generating device is capable of generating the second air vibrations based on the control signal.

[0007] A vehicle according to a third aspect of the present disclosure is a vehicle equipped with a ride comfort improvement device and a vibration generating device. The ride comfort improvement device includes a sensor and a signal generating unit. The sensor is capable of sensing road surface shape while the vehicle is traveling. The signal generating unit is capable of generating a control signal based on the sensor's sensing results and outputting the generated control signal to the vibration generating device. Here, the impact propagates to the head of a vehicle occupant, causing the head to vibrate, and the resulting air vibrations generated relative to the head are referred to as first air vibrations. At this time, the signal generating unit is capable of predicting road surface shape based on the sensor's sensing results, and generating a control signal capable of generating second air vibrations that reach the head at a predetermined timing before the generation of the first air vibrations based on the predicted road surface shape, and outputting the generated control signal to the vibration generating device. The vibration generating device is capable of generating the second air vibrations based on the control signal.

[0008] A ride comfort improvement method according to a fourth aspect of the present disclosure includes the following three steps, when an impact that occurs in a tire or knuckle while the vehicle is traveling is transmitted to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibration that occurs relative to the head is defined as a first air vibration: (1) Obtaining the results of detecting or predicting impacts that occur to tires or knuckles while a vehicle is running (2) generating a control signal capable of generating a second aerial vibration that reaches the head at a predetermined timing before the generation of the first aerial vibration based on the detection result or the prediction result; (3) outputting the generated control signal to the vibration generating device to generate the second air vibration from the vibration generating device; [Brief explanation of the drawings]

[0009] The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate one embodiment and, together with the description, serve to explain the principles of the disclosure.

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of functional blocks of a vehicle according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of a perspective configuration of the vehicle of FIG. [Figure 3] FIG. 3 is a diagram showing, in comparison, an example of a process in which tire vibrations are transmitted to the head of a passenger, and an example of a process in which headphones are vibrated based on tire vibrations detected by a microphone. [Figure 4] FIG. 4 is a diagram showing an example of waveforms of the first aerial vibration and the second aerial vibration of FIG. [Figure 5] FIG. 5 is a diagram illustrating an example of the operation of the vehicle of FIG. [Figure 6] FIG. 6 is a diagram illustrating an example of functional blocks of a vehicle according to the second embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram illustrating an example of a perspective configuration of the vehicle of FIG. [Figure 8] FIG. 8 is a diagram showing, in comparison, an example of the process in which tire vibrations propagate to the head of a passenger, and an example of the process in which headphones are vibrated based on road surface unevenness data detected by a sensor. [Figure 9] FIG. 9 is a diagram illustrating an example of the operation of the vehicle of FIG. [Figure 10] FIG. 10 is a perspective view illustrating a modified example of the vehicle according to the first embodiment. [Figure 11] FIG. 11 is a perspective view illustrating a modified example of the vehicle according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Conventionally, in order to improve the ride comfort of a vehicle, vibrations applied to vehicle occupants have been reduced by adjusting the suspension and seat materials. However, reducing vibrations applied to occupants over a wide frequency range is not easy due to the need to balance this with other performance factors such as handling and stability. While it is possible to reduce vibrations applied to occupants over a wide frequency range by using active suspension, it is not common to install such expensive devices.

[0012] Conventionally, noises such as creaking that occur when a vehicle vibrates have been reduced by adding sound-insulating materials, vibration-damping materials, etc. However, adding sound-insulating materials, vibration-damping materials, etc. increases the cost and weight of the vehicle.

[0013] It is desirable to provide a ride quality improvement device, vehicle, and method that can improve the ride quality of a vehicle over a wide frequency range without relying on active suspension, sound insulation, and vibration isolation materials.

[0014] Some exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the following description illustrates one specific example of the present disclosure and should not be construed as limiting the present disclosure. For example, each element, including numerical values, shapes, materials, parts, the position of each part, and the connection method of each part, is merely an example and should not be construed as limiting the present disclosure. Furthermore, in the following exemplary embodiments, components not described in independent claims based on the highest concept of the present disclosure are optional and may be provided as needed. The drawings are schematic and are not intended to be drawn to scale. Throughout this specification and the drawings, components having substantially the same function and configuration are designated by the same reference numerals, and redundant description will be omitted. Furthermore, components not directly related to one embodiment of the present disclosure are not shown in the drawings.

[0015] <1. First embodiment> [Configuration example] First, a vehicle 1 according to a first embodiment of the present disclosure will be described. FIG. 1 illustrates an example of functional blocks of the vehicle 1 according to the first embodiment of the present disclosure. For example, as shown in FIG. 1, the vehicle 1 includes an impact detection device 10, a control device 20, and a vibration generation device 30. The control device 20 corresponds to a specific example of a "ride comfort improvement device" according to an embodiment of the present disclosure. The vehicle 1 corresponds to a specific example of a "vehicle" according to an embodiment of the present disclosure.

[0016] The impact detection device 10 is configured, for example, by a sound collection device or a vibration detection device. The sound collection device includes, for example, a microphone and is capable of outputting a sound signal obtained by detection by the microphone. The sound collection device is capable of detecting air vibrations generated by vertical vibrations of the front tire 40 or the knuckle 60 connected to the front tire 40 while the vehicle 1 is traveling. The sound collection device is capable of acquiring a sound signal as a detection result by detecting an impact occurring in the front tire 40 or the knuckle 60 as air vibrations while the vehicle 1 is traveling. For example, as shown in FIG. 2, the sound collection device is disposed with a predetermined gap between it and the ground contact surface of the front tire 40 and further disposed directly above the front tire 40.

[0017] The vibration detection device is configured to include, for example, an acceleration sensor, and is capable of outputting a vibration signal obtained by detection by the acceleration sensor. The vibration detection device is capable of detecting, for example, vertical vibrations of the front tire 40 or the knuckle 60 while the vehicle 1 is traveling. The vibration detection device is capable of acquiring, as a detection result, a vibration signal obtained by detecting, for example, an impact occurring in the front tire 40 or the knuckle 60 while the vehicle 1 is traveling as vibrations of the front tire 40 or the knuckle 60. The vibration detection device is fixed, for example, to the wheel of the front tire 40 or the knuckle 60. The impact detection device 10 is capable of outputting a signal obtained by detection (for example, a sound signal or a vibration signal) to the control device 20.

[0018] The control device 20 is capable of generating a control signal based on the detection result (for example, a sound signal or a vibration signal) acquired by the impact detection device 10, and outputting the generated control signal to the vibration generating device 30. The control device 20 includes, for example, a data acquiring unit 21, a signal generating unit 22, a storage unit 23, and a communication unit 24, as shown in FIG.

[0019] The data acquisition unit 21 is capable of acquiring detection results from the impact detection device 10. The data acquisition unit 21 is capable of outputting the acquired detection results to the signal generation unit 22. The signal generation unit 22 is capable of generating a control signal based on the detection results input from the data acquisition unit 21 and the offset 23B read from the storage unit 23.

[0020] 3 compares an example of a process in which vibrations from the front tire 40 propagate to the head of the occupant 100 with an example of a process in which the vibration generating device 30 (headphones) is vibrated based on the vibrations from the front tire 40 detected by the impact detection device 10 (microphone). Here, an impact generated on the front tire 40 or the knuckle 60 while the vehicle 1 is traveling propagates to the head of the occupant 100 of the vehicle 1, causing the head to vibrate. The resulting air vibration generated relative to the head is defined as a first air vibration f1. Based on the detection result obtained by the impact detection device 10, the signal generating unit 22 is capable of generating a control signal capable of generating a second air vibration f2 that reaches the head at a predetermined timing before the generation of the first air vibration f1.

[0021] Here, the "predetermined timing" refers to a timing at which, when the second air vibration f2 is propagated to the head (for example, the ossicles of the middle ear) of the occupant 100, the vibration of the front tire 40 propagates to the head (for example, the ossicles of the middle ear) of the occupant 100 within a period (a response period Tx) during which a physiological reflex (for example, the ossicular reflex) caused by the second air vibration f2 continues. As shown in FIG. 3, the response period Tx is a period that includes the time t2 at which the vibration of the front tire 40 propagates to the head of the occupant 100, and further is a period immediately after the time tc at which the second air vibration f2 propagates to the head (for example, the ossicles of the middle ear) of the occupant 100.

[0022] The difference (offset Δt1) between the time t2 when the vibration of the front tire 40 is transmitted to the head of the occupant 100 and the time tc when the second air vibration f2 is transmitted to the head of the occupant 100 is, for example, within a range of 0.1 to 0.2 seconds. The signal generator 22 is capable of generating a control signal that can generate the second air vibration f2 at a timing (time tc) before the occurrence timing (time t2) of the first air vibration f1, within a range of 0.1 to 0.2 seconds. The signal generator 22 inputs the generated control signal to the vibration generator 30, thereby enabling the vibration generator 30 to generate the second air vibration f2.

[0023] When the ossicular reflex occurs, the impedance of the eardrum increases (i.e., the eardrum becomes harder). At this time, if the vibration of the front tire 40 is transmitted to the head of the occupant 100, the response level of the eardrum to the vibration transmitted to the head of the occupant 100 becomes lower than when the ossicular reflex does not occur. Due to the reduced response level of the eardrum, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure than when the ossicular reflex does not occur.

[0024] The sound pressure of the second aerial vibrations f2 is a value smaller than the sound pressure of the first aerial vibrations f1 that would be generated if the second aerial vibrations f2 were not generated. The signal generating unit 22 is capable of generating a control signal that causes the sound pressure of the second aerial vibrations f2 to be a value smaller than the sound pressure of the first aerial vibrations f1 that would be generated if the second aerial vibrations f2 were not generated. The sound pressure of the second aerial vibrations f2 is, for example, a level that affects hearing in the inaudible range (0.1 Hz to 20 Hz, for example, 120 dB to 140 dB). The signal generating unit 22 is capable of generating a control signal that causes the sound pressure of the second aerial vibrations f2 to be a level that affects hearing in the inaudible range, for example.

[0025] The frequency of the second aerial vibration f2 is 250 Hz or less. The signal generating unit 22 is capable of generating a control signal that sets the frequency of the second aerial vibration f2 to a value of 250 Hz or less. The frequency band of the second aerial vibration f2 is a frequency band that includes the inaudible range, and is, for example, in the range of 0.1 Hz or more and 100 Hz or less or 250 Hz or less. The signal generating unit 22 is capable of generating a control signal that sets the frequency of the second aerial vibration f2 to a value included in the frequency band that includes the inaudible range. The frequency of the first aerial vibration f1 is, for example, a value within the range of 0.1 Hz or more and 100 Hz or less.

[0026] The storage unit 23 is configured, for example, with a non-rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-only Memory). The storage unit 23 stores, for example, a program 23A describing a series of processes executed by the signal generation unit 22, and an offset 23B. The signal generation unit 22 is capable of executing the above-described processes by, for example, loading the program 23A. The offset 23B includes, for example, an offset Δt2. For example, as shown in FIG. 3, the offset Δt2 is the period from when the impact detection device 10 (microphone) detects vibration of the front tire 40 to when the vibration generating device 30 (headphones) starts vibrating. For example, when the signal generation unit 22 acquires a detection result (e.g., a sound signal or a vibration signal) from the data acquisition unit 21, the signal generation unit 22 is capable of outputting a control signal to the vibration generating device 30 when the offset Δt2 has elapsed since the acquisition of the detection result.

[0027] The storage unit 23 may be configured with a rewritable nonvolatile memory such as a flash memory or a resistance-change memory. In this case, the offset Δt2 may be updated, for example, by calibration, which will be described later. Here, the time from when the front tire 40 starts vibrating due to an impact to when the vibration is transmitted to the head of the occupant 100 is defined as a propagation time T1. Also, the time from when the vibration generating device 30 (headphones) starts vibrating in response to a control signal to when the vibration is transmitted to the head of the occupant 100 is defined as a propagation time T2. It is assumed that the propagation times T1 and T2 are acquired in advance by measurement. In this case, the signal generating unit 22 can derive the offset Δt2 based on, for example, the propagation times T1 and T2 obtained by measurement and the offset Δt1, and store the derived offset Δt2 in the storage unit 23. By performing such calibration, the offset Δt2 corresponding to the structural characteristics of the vehicle 1 and the characteristics of the occupant 100 is obtained.

[0028] The communication unit 24 is a communication interface capable of communicating with the vibration generating device 30 via a communication network. The communication unit 24 is capable of transmitting the control signal generated by the signal generating unit 22 to the vibration generating device 30 via the communication network. Note that data transmission and reception between the control device 20 and the vibration generating device 30 may be performed wirelessly or via a wired connection.

[0029] The vibration generating device 30 is capable of generating the second aerial vibration f2 based on a control signal input from the control device 20. The vibration generating device 30 includes, for example, a communication unit that receives the control signal input from the control device 20, an actuator that vibrates a vibrated unit based on the control signal input via the communication unit, and the vibrated unit that is vibrated by the actuator. The vibration generating device 30 is, for example, headphones or earphones that include a pair of speakers. The vibration generating device 30 is capable of generating the second aerial vibration f2, for example, having a waveform shown by the dashed line in FIG. 4. The timing at which the second aerial vibration f2 propagates to the head of the occupant 100 (for example, the ossicles of the middle ear) is earlier by an offset Δt1 than the timing at which the first aerial vibration f1 propagates to the head of the occupant 100 (for example, the ossicles of the middle ear).

[0030] [Operation] Next, the operation of the vehicle 1 will be described with reference to Figures 4 and 5. Figure 5 is a diagram for explaining an example of the operation of the vehicle 1.

[0031] Assume that the vehicle 1 is traveling on a road. At this time, the vehicle 1 goes over an uneven road surface, causing vertical vibrations in the front tires 40 (time t1). The impact detection device 10 detects the vertical vibrations of the front tires 40 and outputs the detection result (for example, a sound signal or a vibration signal) to the control device 20 (time ta).

[0032] The control device 20 determines whether the impact detection device 10 has detected vertical vibration of the front tire 40 (step S101). When the detection result is input from the impact detection device 10, the control device 20 determines that the impact detection device 10 has detected vertical vibration of the front tire 40 (step S101; Y). The control device 20 generates a control signal based on the detection result acquired by the impact detection device 10. The control device 20 reads out an offset Δt2 from the storage unit 23, and outputs a control signal to the vibration generating device 30 when a time equal to the offset Δt2 has elapsed since the detection result was acquired from the impact detection device 10 (step S102). The vibration generating device 30 generates a second air vibration f2 based on the control signal input from the control device 20 (time tb, step S103).

[0033] As a result, the second air vibration f2 propagates to the head of the occupant 100 (e.g., the ossicles of the middle ear) at time tc, and a physiological reflex (e.g., the ossicular reflex) occurs due to the second air vibration f2. The physiological reflex (e.g., the ossicular reflex) continues for a period (a reaction period Tx) immediately after time tc when the second air vibration f2 propagates to the head of the occupant 100 (e.g., the ossicles of the middle ear). Meanwhile, the vibration of the front tire 40 propagates to the head (e.g., the skull) of the occupant 100 via the body of the vehicle 1, etc. As a result, the vibration propagated to the head (e.g., the skull) of the occupant 100 via the body of the vehicle 1, etc., vibrates the head (e.g., the skull) of the occupant 100, which causes a first air vibration f1 to be generated relative to the head (e.g., the skull) (time t2).

[0034] At this time, the timing at which the first air vibration f1 is propagated to the head of the occupant 100 (for example, the ossicles of the middle ear) via the vehicle 1 frame or the like (the timing at which the middle ear bones start to vibrate due to the first air vibration f1) is within a period (reaction period Tx) during which a physiological reflex (for example, the ossicular reflex) continues. Therefore, the response level of the eardrum to the vibration propagated to the head of the occupant 100 via the vehicle 1 frame or the like is lower than when the ossicular reflex is not occurring. Due to the lower response level of the eardrum, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure than when the ossicular reflex is not occurring.

[0035] [effect] Next, the effects of the vehicle 1 according to the first embodiment of the present disclosure will be described.

[0036] In this embodiment, based on the detection result of an impact occurring in the front tire 40 or the knuckle 60 while the vehicle 1 is traveling, a second air vibration f2 is generated, which reaches the head of the occupant 100 at a predetermined timing before the generation of the first air vibration f1. As a result, the vibration reaches the head of the occupant 100 via the vehicle 1 frame and the like during a period (a response period Tx) during which a physiological reflex (e.g., ossicular reflex) occurring in the second air vibration f2 continues. As a result, the response level of the eardrum to the vibration propagated to the head of the occupant 100 via the vehicle 1 frame and the like is lower than when a physiological reflex (e.g., ossicular reflex) occurring in the second air vibration f2 does not occur. Due to the lower response level of the eardrum, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure than when an ossicular reflex does not occur. Here, the perceived level of the sound pressure of the first air vibration f1 has a significant correlation with the ride comfort of the occupant 100. The lower the perceived level of the sound pressure of the first aerial vibrations f1, the less likely the occupant 100 will feel that the ride is uncomfortable.

[0037] In this embodiment, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure than when the ossicular reflex does not occur. Therefore, even if the vibration propagates to the head of the occupant 100 via the body of the vehicle 1, the occupant 100 is unlikely to feel an uncomfortable ride. Note that physiological reflexes (e.g., ossicular reflexes) occur over a wide range of frequencies, including the inaudible range. As a result, the ride comfort of the vehicle 1 can be improved over a wide frequency range without relying on active suspension, sound insulation materials, or vibration-damping materials.

[0038] In this embodiment, the second aerial vibrations f2 are generated based on a sound signal obtained by detecting an impact that has occurred on the vehicle 1 as aerial vibrations. This eliminates the need to prepare sound source data for generating the second aerial vibrations f2 in advance, and allows the second aerial vibrations f2 to be generated in a simple manner. Furthermore, this detection method offers greater flexibility in installing measuring instruments compared to methods that directly measure vibrations. While methods that directly measure vibrations require sensors to be installed near the knuckles, aerial vibrations allow installation in locations that do not actually experience stroke, such as wheel wells or the frame.

[0039] In this embodiment, the second aerial vibration f2 is generated within a range of 0.1 to 0.2 seconds, prior to the generation of the first aerial vibration f1. As a result, the vibration reaches the head of the occupant 100 via the vehicle 1 frame and the like during the period (response period Tx) during which a physiological reflex (e.g., ossicular reflex) caused by the second aerial vibration f2 continues. As a result, the sound pressure of the first aerial vibration f1 is perceived as lower than when the ossicular reflex is not occurring. Therefore, even if the vibration propagates to the head of the occupant 100 via the vehicle 1 frame and the like, the occupant 100 is unlikely to feel an uncomfortable ride. As a result, the ride comfort of the vehicle 1 can be improved over a wide frequency range without relying on active suspension, sound insulation materials, or vibration-damping materials.

[0040] In this embodiment, the sound pressure of the second aerial vibration f2 is set to a value smaller than the sound pressure of the first aerial vibration f1. A physiological reflection (for example, the ossicular reflex) caused by the second aerial vibration f2 occurs even when the sound pressure of the second aerial vibration f2 is of this magnitude. Therefore, by using the vibration generator 30, it is possible to reduce the scale of low-frequency vibration and noise countermeasures (for example, active suspension, strengthening of the vehicle body structure, modification of seat cushions, etc.) that would be required without the vibration generator 30. This makes it possible to reduce the cost of vibration and noise countermeasures.

[0041] <2. Second Embodiment> Next, a vehicle 2 according to a second embodiment of the present disclosure will be described. FIG. 6 illustrates an example of functional blocks of the vehicle 2 according to the second embodiment of the present disclosure. For example, as shown in FIG. 6, the vehicle 2 includes a vehicle speed sensor 70, a road unevenness sensor 80, a control device 90, and a vibration generating device 30. The control device 90 corresponds to a specific example of a "ride comfort improvement device" according to an embodiment of the present disclosure. The vehicle 2 corresponds to a specific example of a "vehicle" according to an embodiment of the present disclosure.

[0042] The vehicle speed sensor 70 is capable of detecting the speed (vehicle speed) of the vehicle 1. The vehicle speed sensor 70 is capable of measuring, for example, the rotational speed of the front tires 40 and deriving the speed (vehicle speed) of the vehicle 1 based on the measurement results. The vehicle speed sensor 70 is capable of outputting data on the obtained vehicle speed (vehicle speed data) to the control device 90. The vehicle speed sensor 70 is disposed, for example, near the front tires 40 as shown in FIG. 7.

[0043] The road surface unevenness sensor 80 is capable of detecting unevenness on the road surface ahead of the vehicle 1. The road surface unevenness sensor 80 is capable of sensing the road surface shape while the vehicle 1 is traveling. The road surface unevenness sensor 80 is capable of, for example, irradiating the road surface ahead of the vehicle 1 with laser light and detecting the reflected light, and deriving the unevenness of the road surface ahead of the vehicle 1 based on the detection results. The road surface unevenness sensor 80 is capable of outputting data on the obtained unevenness (unevenness data) to the control device 90. The road surface unevenness sensor 80 is arranged in front of the vehicle 1, for example, as shown in FIG. 7.

[0044] The control device 90 is capable of generating a sound signal corresponding to the sound signal in the first embodiment described above, based on data (vehicle speed data and road surface irregularity data) about the road surface shape obtained by sensing using the vehicle speed sensor 70 and the road surface irregularity sensor 80. The generated sound signal corresponds to a prediction result of an impact that will occur to the front tires 40 or the knuckles 60 while the vehicle 2 is traveling, or the road surface shape that is the cause of the impact. The control device 90 acquires the sound signal generated based on the data about the road surface shape obtained by sensing using the vehicle speed sensor 70 and the road surface irregularity sensor 80 as the prediction result. The control device 90 is further capable of generating a control signal based on the generated sound signal and outputting the generated control signal to the vibration generating device 30. The control device 90 includes, for example, a data acquiring unit 91, a signal generating unit 92, a storage unit 93, and a communication unit 94, as shown in FIG. 6 .

[0045] The data acquisition unit 91 is capable of acquiring data on the road surface shape (vehicle speed data and unevenness data) from the vehicle speed sensor 70 and the road surface unevenness sensor 80. The data acquisition unit 91 is capable of outputting the acquired data on the road surface shape to the signal generation unit 92. The signal generation unit 92 is capable of generating a sound signal corresponding to the sound signal in the first embodiment described above, based on the data on the road surface shape input from the data acquisition unit 91 and sound source data 93C read from the storage unit 93. For example, the signal generation unit 92 is capable of generating a correction coefficient for the sound source data 93C based on the data on the road surface shape input from the data acquisition unit 91, and correcting the sound source data 93C using the generated correction coefficient, thereby generating a sound signal corresponding to the sound signal in the first embodiment described above. The signal generation unit 92 is capable of generating a control signal based on the generated sound signal and an offset 93B read from the storage unit 93.

[0046] 8 compares an example of a process in which vibrations from the front tire 40 propagate to the head of the occupant 100 with an example of a process in which the vibration generating device 30 (headphones) is vibrated based on data about the road surface shape obtained by sensing with the vehicle speed sensor 70 and the road surface unevenness sensor 80. Here, an impact generated on the front tire 40 or the knuckle 60 while the vehicle 2 is traveling propagates to the head of the occupant 100 of the vehicle 2, causing the head to vibrate. The air vibration generated relative to the head as a result is referred to as a first air vibration f1. The signal generating unit 92 is capable of generating a control signal that can generate a second air vibration f2 that reaches the head at a predetermined timing before the generation of the first air vibration f1, based on data about the road surface shape obtained by sensing with the vehicle speed sensor 70 and the road surface unevenness sensor 80.

[0047] Here, the "predetermined timing" refers to a timing at which, when the second air vibration f2 is propagated to the head (for example, the ossicles of the middle ear) of the occupant 100, the vibration of the front tire 40 propagates to the head (for example, the skull) of the occupant 100 within a period (a response period Tx) during which a physiological reflex (for example, the ossicular reflex) caused by the second air vibration f2 continues. As shown in FIG. 8, the response period Tx is a period that includes the time t2 at which the vibration of the front tire 40 propagates to the head of the occupant 100, and further is a period immediately after the time tc at which the second air vibration f2 propagates to the head of the occupant 100 (for example, the ossicles of the middle ear).

[0048] The difference (offset Δt1) between the time t2 when the vibration of the front tire 40 is transmitted to the head of the occupant 100 and the time tc when the second air vibration f2 is transmitted to the head of the occupant 100 is, for example, within a range of 0.1 to 0.2 seconds. The signal generating unit 92 is capable of generating a control signal that can generate the second air vibration f2 at a timing (time tc) before the occurrence timing (time t2) of the first air vibration f1, within a range of 0.1 to 0.2 seconds.

[0049] The storage unit 93 is configured, for example, by a non-rewritable non-volatile memory such as an EEPROM. The storage unit 93 stores, for example, a program 93A describing a series of processes to be executed by the signal generation unit 92, an offset 93B, and sound source data 93C. The signal generation unit 92 is able to execute the above-mentioned processes by, for example, loading the program 93A.

[0050] The offset 93B includes, for example, an offset Δt3. For example, as shown in FIG. 8, the offset Δt3 is the period from when an unevenness in the road surface ahead of the vehicle 1 is detected by sensing using the road unevenness sensor 80 to when the vibration generator 30 (headphones) starts vibrating. For example, when the signal generator 92 acquires data about the road surface shape (vehicle speed data and unevenness data) from the data acquirer 91, the signal generator 92 is able to output a control signal to the vibration generator 30 when a time equal to the offset Δt3 has elapsed since the acquisition of the data about the road surface shape. The sound source data 93C includes, for example, time-series data of a typical sound signal acquired when an impact is applied to the front tire 40.

[0051] The storage unit 93 may be configured with a rewritable nonvolatile memory such as a flash memory or a resistance-change memory. In this case, the offset Δt3 may be updated, for example, by calibration, which will be described later. Here, the time from when the front tire 40 starts vibrating due to an impact to when the vibration is transmitted to the head of the occupant 100 is defined as a propagation time T1. Also, the time from when the vibration generating device 30 (headphones) starts vibrating in response to a control signal to when the vibration is transmitted to the head of the occupant 100 is defined as a propagation time T2. It is assumed that the propagation times T1 and T2 are acquired in advance by measurement. In this case, the signal generating unit 92 can derive the offset Δt3 based on, for example, the propagation times T1 and T2 obtained by measurement and the offset Δt1, and store the derived offset Δt3 in the storage unit 93. By performing such calibration, the offset Δt3 corresponding to the structural characteristics of the vehicle 2 and the characteristics of the occupant 100 can be obtained.

[0052] The communication unit 94 is a communication interface capable of communicating with the vibration generating device 30 via a communication network. The communication unit 94 is capable of transmitting the control signal generated by the signal generating unit 92 to the vibration generating device 30 via the communication network. Note that data transmission and reception between the control device 90 and the vibration generating device 30 may be performed wirelessly or via a wired connection.

[0053] The vibration generating device 30 is capable of generating the second aerial vibration f2 based on a control signal input from the control device 90. The vibration generating device 30 includes, for example, a communication unit that receives the control signal input from the control device 90, an actuator that vibrates a vibrated unit based on the control signal input via the communication unit, and the vibrated unit that is vibrated by the actuator. The vibration generating device 30 is, for example, headphones or earphones that include a pair of speakers. The vibration generating device 30 is capable of generating the second aerial vibration f2, for example, having a waveform shown by the dashed line in FIG. 4. The timing at which the second aerial vibration f2 propagates to the head of the occupant 100 (for example, the ossicles of the middle ear) is earlier by an offset Δt1 than the timing at which the first aerial vibration f1 propagates to the head of the occupant 100 (for example, the ossicles of the middle ear).

[0054] [Operation] Next, the operation of the vehicle 2 will be described with reference to Figures 8 and 9. Figure 9 is a diagram for explaining an example of the operation of the vehicle 2.

[0055] Assume that the vehicle 2 is traveling on a road. At this time, the control device 90 acquires data on the road surface shape (vehicle speed data and unevenness data) through sensing by the vehicle speed sensor 70 and the road surface unevenness sensor 80. Based on the data on the road surface shape, the control device 90 predicts whether the front tire 40 or the knuckle 60 will receive an impact while the vehicle 2 is traveling (step S201). As a result, if it is predicted that the vehicle 2 will receive an impact (step S201; Y), the control device 90 generates a sound signal based on time-series data of the location where the vehicle 2 is predicted to receive an impact, among the data on the road surface shape, and on sound source data 93C read from the storage unit 93. The generated sound signal corresponds to a prediction result of an impact that will occur to the front tire 40 or the knuckle 60 while the vehicle 2 is traveling. The control device 90 acquires the sound signal generated based on the data on the road surface shape through sensing by the vehicle speed sensor 70 and the road surface unevenness sensor 80 as a prediction result.

[0056] The control device 90 generates a control signal based on the generated sound signal (prediction result). The control device 90 reads out the offset Δt3 from the storage unit 93, and outputs a control signal to the vibration generator 30 when a time equal to the offset Δt3 has elapsed since the data predicting that the vehicle 2 will receive an impact was acquired (since the road surface unevenness was detected) (step S202). The vibration generator 30 generates a second aerial vibration f2 based on the control signal input from the control device 90 (time te, step S203).

[0057] As a result, the second air vibration f2 propagates to the head of the occupant 100 (e.g., the ossicles of the middle ear) at time tf, and a physiological reflex (e.g., the ossicular reflex) occurs due to the second air vibration f2. The physiological reflex (e.g., the ossicular reflex) continues for a period (a reaction period Tx) immediately after time tf when the second air vibration f2 propagates to the head of the occupant 100 (e.g., the ossicles of the middle ear). Meanwhile, the vibration of the front tire 40 propagates to the head of the occupant 100 (e.g., the ossicles of the middle ear) via the body of the vehicle 2, etc. As a result, the vibration propagated to the head of the occupant 100 (e.g., the skull) via the body of the vehicle 2, etc., vibrates the head of the occupant 100 (e.g., the skull), which causes a first air vibration f1 to be generated relative to the head (e.g., the skull) (time t2).

[0058] At this time, the timing at which the first air vibration f1 is propagated to the head (e.g., skull) of the occupant 100 via the body of the vehicle 2 or the like (the timing at which the first air vibration f1 is generated) is within a period (a reaction period Tx) during which a physiological reflex (e.g., ossicular reflex) continues. Therefore, compared to when the ossicular reflex is not occurring, the response level of the eardrum to the air vibration f1 generated by the vibration propagated to the head of the occupant 100 via the body of the vehicle 2 or the like is lower. Due to the lower response level of the eardrum, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure compared to when the ossicular reflex is not occurring.

[0059] [effect] Next, the effects of the vehicle 2 according to the second embodiment of the present disclosure will be described.

[0060] In this embodiment, based on the prediction result of an impact that will occur in the front tire 40 or the knuckle 60 while the vehicle 2 is traveling, a second air vibration f2 is generated, which reaches the head of the occupant 100 at a predetermined timing before the generation of the first air vibration f1. As a result, the vibration reaches the head of the occupant 100 via the vehicle 2 frame and the like during a period (a response period Tx) during which a physiological reflex (e.g., ossicular reflex) caused by the second air vibration f2 continues. As a result, the response level of the eardrum to the air vibration f1 generated by the vibration propagated to the head of the occupant 100 via the vehicle 2 frame and the like is lower than when a physiological reflex (e.g., ossicular reflex) caused by the second air vibration f2 does not occur. Due to the lower response level of the eardrum, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure than when the ossicular reflex does not occur. Here, the magnitude of the sound pressure of the first air vibration f1 has a significant correlation with the ride comfort of the occupant 100. The lower the perceived level of the sound pressure of the first aerial vibrations f1, the less likely the occupant 100 will feel that the ride is uncomfortable.

[0061] In this embodiment, the sound pressure of the first air vibration f1 is perceived as a lower sound pressure than when the ossicular reflex does not occur. Therefore, even if the vibration propagates to the head of the occupant 100 via the body of the vehicle 2, the occupant 100 is unlikely to feel an uncomfortable ride. Note that physiological reflexes (for example, the ossicular reflex) occur over a wide range of frequencies, including the inaudible range. As a result, the ride comfort of the vehicle 2 can be improved over a wide frequency range without relying on active suspension, sound insulation materials, or vibration-damping materials.

[0062] In this embodiment, a sound signal is generated based on data about the road surface shape (vehicle speed data and road surface unevenness data) obtained by sensing using the vehicle speed sensor 70 and the road surface unevenness sensor 80, and the second airborne vibration f2 is generated based on the generated sound signal. As a result, in the method of the first embodiment in which the impact detection device 10 detects an impact on the front tire 40, for example, even when there is not enough time to generate the second airborne vibration f2 (for example, when the vehicle 2 is traveling at high speed), the ride comfort of the vehicle 2 can be improved over a wide frequency band. By using sound source data, it is no longer necessary to place sensors around the tires as in the first embodiment. This makes it easier to avoid sensor damage caused by the sensor touching down, stones flying off, or snow accumulation, and reduces the design costs around the sensor.

[0063] In this embodiment, the second aerial vibration f2 is generated within a range of 0.1 to 0.2 seconds, at a timing prior to the generation timing of the first aerial vibration f1. As a result, the vibration reaches the head of the occupant 100 via the vehicle 2 frame and the like during the period (response period Tx) during which a physiological reflex (e.g., ossicular reflex) caused by the second aerial vibration f2 continues. As a result, the sound pressure of the first aerial vibration f1 is perceived as lower than when the ossicular reflex is not occurring. Therefore, even if the vibration propagates to the head of the occupant 100 via the vehicle 2 frame and the like, the occupant 100 is unlikely to feel an uncomfortable ride. As a result, the ride comfort of the vehicle 2 can be improved over a wide frequency band without relying on active suspension, sound insulation materials, or vibration-damping materials.

[0064] In this embodiment, the sound pressure of the second aerial vibration f2 is set to a value smaller than the sound pressure of the first aerial vibration f1. A physiological reflection (for example, the ossicular reflex) caused by the second aerial vibration f2 occurs even when the sound pressure of the second aerial vibration f2 is of this magnitude. Therefore, by using the vibration generator 30, it is possible to reduce the scale of low-frequency vibration and noise countermeasures (for example, active suspension, strengthening of the vehicle body structure, modification of seat cushions, etc.) that would be required without the vibration generator 30. This makes it possible to reduce the cost of vibration and noise countermeasures.

[0065] 3. Modifications of each embodiment Although the present disclosure has been described above using two embodiments, the present disclosure is not limited to these embodiments and various modifications are possible.

[0066] [Variation A] In each of the above-described embodiments, the vibration generating device 30 may be disposed on the roof trim of the vehicle 1, 2, as shown in Fig. 10 and Fig. 11. In this case, the vibration generating device 30 includes, for example, a communication unit that receives a control signal input from the control device 20, 90, an actuator that vibrates a flat plate installed on the roof trim of the vehicle 1, 2 based on the control signal input via the communication unit, and the flat plate vibrated by the actuator. In this case, the ride comfort of the vehicle 1, 2 can be improved over a wide frequency band without requiring the occupant 100 to wear headphones or earphones.

[0067] [Variation B] In the first embodiment and its modifications, the impact detector 10 may be a sound collector capable of detecting airborne vibrations generated by vertical vibrations of the rear tire 50 or a knuckle connected to the rear tire 50. Also, in the first embodiment and its modifications, the impact detector 10 may be a vibration detector capable of detecting vertical vibrations of the rear tire 50 or a knuckle connected to the rear tire 50. Even in this case, the ride comfort of the vehicle 1 can be improved over a wide frequency band, as in the above embodiment and its modifications.

[0068] The effects described in this specification are merely examples, and the effects of the present disclosure are not limited to the effects described in this specification. Therefore, other effects may be obtained with respect to the present disclosure.

[0069] Furthermore, the present disclosure may take the following aspects. (1) an acquisition unit capable of acquiring a detection result or a prediction result of an impact occurring to a tire or a knuckle while the vehicle is running; a signal generating unit that generates a control signal based on the detection result or the prediction result acquired by the acquiring unit and outputs the generated control signal to a vibration generating device; Equipped with The signal generation unit When the impact propagates to the head of the vehicle occupant, causing the head to vibrate, and the resulting air vibration generated relative to the head is defined as a first air vibration, generating a control signal capable of generating a second air vibration that reaches the head at a predetermined timing before the generation of the first air vibration, based on the detection result or the prediction result; outputting the generated control signal to the vibration generating device to cause the vibration generating device to generate the second air vibration; It is now possible to Ride comfort improvement device. (2) The signal generating unit is capable of acquiring a sound signal obtained by detecting the impact as an air vibration as the detection result. (1) A ride comfort improvement device according to the present invention. (3) The signal generating unit is capable of acquiring, as the prediction result, a sound signal generated based on data on the road surface shape obtained by sensing. (1) A ride comfort improvement device according to the present invention. (4) The signal generating unit is capable of generating, as the control signal, a signal that can generate the second aerial vibration at a timing that is within a range of 0.1 seconds to 0.2 seconds and that is prior to the timing of generation of the first aerial vibration. A ride comfort improvement device according to any one of (1) to (3). (5) The signal generating unit is capable of generating, as the control signal, a signal that causes the sound pressure of the second aerial vibrations to have a value smaller than the sound pressure of the first aerial vibrations that would be generated if the second aerial vibrations were not generated. A ride comfort improvement device according to any one of (1) to (3). (6) The signal generating unit is capable of generating, as the control signal, a signal that causes the frequency of the second aerial vibration to be 250 Hz or less. A ride comfort improvement device according to any one of (1) to (3). (7) A vehicle equipped with a ride comfort improvement device and a vibration generating device, The ride comfort improvement device includes: a sensor capable of detecting an impact that occurs to a tire or a knuckle while the vehicle is running; a signal generating unit that generates a control signal based on the detection result of the impact by the sensor and outputs the generated control signal to the vibration generating device; and The signal generation unit When the impact propagates to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibrations generated relative to the head are defined as first air vibrations, generating, as the control signal, a control signal capable of generating second air vibrations that reach the head at a predetermined timing before the generation of the first air vibrations, based on the detection result; outputting the generated control signal to the vibration generating device; It is possible to do the following, The vibration generating device is capable of generating the second air vibration based on the control signal. vehicle. (8) A vehicle equipped with a ride comfort improvement device and a vibration generating device, The ride comfort improvement device includes: a sensor capable of sensing the road surface shape while the vehicle is traveling; a signal generating unit that generates a control signal based on a sensing result by the sensor and outputs the generated control signal to the vibration generating device; and The signal generation unit predicting the road surface shape based on the sensing result; When an impact generated in a tire or a knuckle while the vehicle is traveling is transmitted to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibration generated relative to the head is defined as a first air vibration, generating, as the control signal, a control signal capable of generating a second air vibration that reaches the head at a predetermined timing before the generation of the first air vibration, based on the predicted result of the road surface shape; outputting the generated control signal to the vibration generating device; It is possible to do the following, The vibration generating device is capable of generating the second air vibration based on the control signal. vehicle. (9) Obtaining a detection result or a prediction result of an impact occurring to a tire or a knuckle while the vehicle is running; When an impact generated in the tire or the knuckle while the vehicle is running is transmitted to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibration generated relative to the head is defined as a first air vibration, generating a control signal capable of generating a second air vibration that reaches the head at a predetermined timing before the generation of the first air vibration based on the detection result or the prediction result; outputting the generated control signal to a vibration generating device, thereby causing the vibration generating device to generate the second air vibration; Contains How to improve ride comfort.

[0070] The controller 20 shown in FIG. 1 and the controller 90 shown in FIG. 6 can be implemented by circuitry including at least one semiconductor integrated circuit, such as at least one processor (e.g., a central processing unit (CPU)), at least one application-specific integrated circuit (ASIC), and / or at least one field-programmable gate array (FPGA). The at least one processor can be configured to perform all or a portion of the various functions of the controller 20 shown in FIG. 1 and the controller 90 shown in FIG. 6 by reading instructions from at least one non-transitory, tangible computer-readable medium. Such media can take various forms, including, but not limited to, various magnetic media such as hard disks, various optical media such as CDs or DVDs, and various semiconductor memories (i.e., semiconductor circuits) such as volatile or non-volatile memories. Volatile memories can include DRAM and SRAM. Non-volatile memories can include ROM and NVRAM. An ASIC is an integrated circuit (IC) specialized to perform all or a portion of the various functions of the controller 20 shown in FIG. 1 and the controller 90 shown in FIG. 6. An FPGA is an integrated circuit that is designed to be configurable after manufacture so as to perform all or part of the various functions of the control device 20 shown in FIG. 1 and the control device 90 shown in FIG. [Explanation of symbols]

[0071] 1,2...vehicle, 10...impact detection device, 20...control device, 21...data acquisition unit, 22...signal generation unit, 23...memory unit, 23A...program, 23B...offset, 24...communication unit, 30...vibration generation device, 40...front tire, 50...rear tire, 60...knuckle, 100...occupant, f1...first air vibration, f2...second air vibration, t1,t2,ta,tb,tc,td,te,tf...time, T1,T2...propagation time, Tx...reaction period, Δt1,Δt2...offset.

Claims

1. an acquisition unit capable of acquiring a detection result or a prediction result of an impact occurring to a tire or a knuckle while the vehicle is running; a signal generating unit that generates a control signal based on the detection result or the prediction result acquired by the acquiring unit and outputs the generated control signal to a vibration generating device; Equipped with The signal generation unit When the impact propagates to the head of the vehicle occupant, causing the head to vibrate and resulting in air vibrations occurring relative to the head being referred to as first air vibrations, generating a control signal capable of generating second air vibrations that reach the head at a predetermined timing before the occurrence of the first air vibrations, based on the detection result or the prediction result; outputting the generated control signal to the vibration generating device to cause the vibration generating device to generate the second air vibration; It is now possible to Ride comfort improvement device.

2. The signal generating unit is capable of acquiring a sound signal obtained by detecting the impact as an air vibration as the detection result.

2. The ride comfort improving device of claim 1.

3. The signal generating unit is capable of acquiring, as the prediction result, a sound signal generated based on data on the road surface shape obtained by sensing.

2. The ride comfort improving device of claim 1.

4. A vehicle equipped with a ride comfort improvement device and a vibration generating device, The ride comfort improvement device includes: a sensor capable of detecting an impact that occurs to a tire or a knuckle while the vehicle is running; a signal generating unit that generates a control signal based on the detection result of the impact by the sensor and outputs the generated control signal to the vibration generating device; and The signal generation unit when the impact propagates to the head of an occupant of the vehicle, causing the head to vibrate and resulting in aerial vibrations occurring relative to the head being defined as first aerial vibrations, generating, as the control signal, a control signal capable of generating second aerial vibrations that reach the head at a predetermined timing before the occurrence of the first aerial vibrations, based on the detection result; outputting the generated control signal to the vibration generating device; It is now possible to The vibration generating device is capable of generating the second air vibration based on the control signal. vehicle.

5. A vehicle equipped with a ride comfort improvement device and a vibration generating device, The ride comfort improvement device includes: a sensor capable of sensing the road surface shape while the vehicle is traveling; a signal generating unit that generates a control signal based on a sensing result by the sensor and outputs the generated control signal to the vibration generating device; and The signal generation unit predicting the road surface shape based on the sensing result; When an impact generated in a tire or a knuckle while the vehicle is traveling is transmitted to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibration generated relative to the head is defined as a first air vibration, generating, as the control signal, a control signal capable of generating a second air vibration that reaches the head at a predetermined timing before the generation of the first air vibration, based on the predicted result of the road surface shape; outputting the generated control signal to the vibration generating device; It is now possible to The vibration generating device is capable of generating the second air vibration based on the control signal. vehicle.

6. Obtaining a detection result or a prediction result of an impact occurring to a tire or a knuckle while the vehicle is running; When an impact generated in the tire or the knuckle while the vehicle is running is transmitted to the head of an occupant of the vehicle, causing the head to vibrate, and the resulting air vibration generated relative to the head is defined as a first air vibration, a control signal is generated based on the detection result or the prediction result, capable of generating a second air vibration that reaches the head at a predetermined timing before the generation of the first air vibration; outputting the generated control signal to a vibration generating device to cause the vibration generating device to generate the second air vibration; Contains How to improve ride comfort.

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