Information presentation device

Abstract

Provided is an information presentation device for improving the ability of an occupant to recognize vehicle behavior without changing the actual riding comfort. An information presentation device (100) provided in a vehicle (1) having a body supported by a suspension device (20) is provided with a behavior detection unit (30, 40) for detecting a parameter correlated with the behavior of the body, a vibration waveform generation unit (110) for generating a vibration waveform, a vibration unit (170) for vibrating the air around the occupant and / or a component in contact with the occupant using the vibration waveform, and a gain adjustment unit (130) for increasing the output gain of the vibration waveform in accordance with the increase in the parameter.

Description

Information presentation device

[0001] The present invention relates to an information presentation device that conveys information about the behavior of a vehicle to a vehicle occupant.

[0002] As a technology for presenting information to vehicle occupants such as the driver, for example, Patent Document 1 describes a vehicle seat or the like that presents warning information indicating a detected dangerous state by adjusting at least one of the vibration frequency, vibration presentation time, vibration amplitude, and presentation time interval of multiple vibrators to the tactile characteristics of humans in response to stimuli caused by applied vibrations, in order to reliably present information without causing discomfort or strangeness to the driver, and by causing selected multiple vibrators to vibrate in a predetermined order in response to a detected dangerous state so that the driver perceives an apparent motion phenomenon.Patent Document 2 describes applying vibrations to which Meissner's corpuscles and Pacinian corpuscles respond, to multiple presentation surfaces provided on the seat cushion, backrest, armrest, etc., in order to present information to a user through somatic sensation. Patent Literature 3 describes an in-vehicle system including a haptic output device that determines haptic feedback to be presented by the system based on information related to the surroundings, environment, and state of the vehicle and generates haptic feedback for the driver of the vehicle, in order to enhance the driver's awareness of the driving situation and surroundings in a continuous and intuitive manner and more effectively improve the driver's ability to react to emergency situations. It also describes providing haptic feedback to the driver of the vehicle when skidding or turning.

[0003] JP 2008-77631 A JP 2019-26216 A JP 2021-93175 A

[0004] Active damper systems, which vary the damping force characteristics of dampers installed in a vehicle's suspension system according to the driving situation, can vary ride comfort and driving performance from comfort to sportiness depending on the situation. However, damping force characteristics that provide a comfortable ride have a low vibration transmission rate from the road surface, which can lead to the driver feeling that information from the road surface is weak. This can lead to a sense of anxiety in the driver. As such, it is difficult to achieve both a setting that provides a comfortable ride and a setting that provides good handling stability. When the driver and other passengers have different requirements, it is difficult to simultaneously resolve these issues. In consideration of the above-mentioned problems, an object of the present invention is to provide an information presentation device that improves passenger awareness of vehicle behavior without changing the actual ride comfort.

[0005] To solve the above-mentioned problems, one aspect of the present invention provides an information presentation device that is installed in a vehicle having a vehicle body supported by a suspension system, and that includes: a behavior detection unit that detects a parameter correlated with the behavior of the vehicle body; a vibration waveform generation unit that generates a vibration waveform; a vibration unit that uses the vibration waveform to vibrate at least one of the air around an occupant and a component in contact with the occupant; and a gain adjustment unit that increases the output gain of the vibration waveform in response to an increase in the parameter. In this way, by increasing the amplitude of the vibration waveform in response to an increase in the parameter correlated with the behavior of the vehicle body, the occupant can be made aware of the vehicle body behavior through sound and vibration without changing the actual ride comfort. This improves drivability.

[0006] In the present invention, the parameters may include a parameter correlated with at least one of a pitch rate and a roll rate of the vehicle body, whereby vehicle behavior can be appropriately reflected in information presentation using parameters that are relatively easy to obtain.

[0007] In the present invention, the vehicle may be configured to accommodate a plurality of occupants, and the vibration unit may be configured to vibrate only some of the occupants, thereby making it possible to provide or stop providing appropriate information to each of the occupants who have different requirements for understanding vehicle behavior.

[0008] In the present invention, the excitation waveform may have a dominant frequency within a frequency range of 100 to 400 Hz. This allows the use of Pacinian corpuscles, which are in the audible range and highly sensitive to cutaneous sensation, and improves the occupant's perception of sound and cutaneous sensation. This allows for more reliable transmission of information to the occupant. More preferably, the dominant frequency is set within a frequency range of 150 to 300 Hz, thereby utilizing a region with higher receptor sensitivity and enhancing the above-mentioned effects.

[0009] In the present invention, the gain adjustment unit may be configured to set the output gain so that the sound pressure generated by the vibration of the vibration unit does not become dominant at the ear of at least one occupant relative to background noise while the vehicle is running. This prevents the sound generated by the vibration of the vibration unit from being drowned out by background noise of the vehicle, which may cause the occupant to feel uncomfortable, and allows information to be transmitted appropriately.

[0010] As described above, according to the present invention, it is possible to provide an information presentation device that improves the occupant's awareness of vehicle behavior without changing the actual ride comfort.

[0011] FIG. 1 is a diagram schematically showing the configuration of a vehicle in which an embodiment of an information presentation device to which the present invention is applied is installed. FIG. 2 is a diagram schematically showing the system configuration of the information presentation device of the first embodiment. FIG. 3 is a diagram schematically showing an example of an excitation waveform in the first embodiment. FIG. 4 is a diagram schematically showing the timing of an electrical pulse emitted by a receptor when stimulated. FIG. 5 is a diagram showing the sensitivity distribution of Pacinian corpuscles and Meissner corpuscles with respect to frequency. FIG. 6 is a diagram schematically showing an example of gain adjustment in a first gain adjustment unit. FIG. 7 is a diagram schematically showing an example of an output history of a microphone. FIG. 8 is a diagram showing an example of a correlation between the sound pressure of background noise and the frequency. FIG. 9 is a diagram schematically showing an example of gain adjustment in a second gain adjustment unit. FIG. 10 is a diagram schematically showing the layout of the interior of a vehicle in which an information presentation device of the first embodiment is installed. FIG. 11 is a graph showing the correlation between the roll rate of a vehicle and the movement of a driver's head.

[0012] <First Embodiment> A first embodiment of an information presentation device to which the present invention is applied will be described below. The information presentation device of the first embodiment is installed in an automobile such as a passenger car, and presents information regarding the behavior of the vehicle body to an occupant (typically a driver D) by means of acoustic information. Fig. 1 is a diagram schematically showing the configuration of a vehicle in which the information presentation device of the embodiment is installed. The vehicle 1 is a four-wheel vehicle having a front right wheel FWR, a front left wheel FWL, a rear right wheel RWR, and a rear left wheel RWL.

[0013] The right front wheel FWR is attached to the right front housing 10FR. The left front wheel FWL is attached to the left front housing 10FL. The right rear wheel RWR is attached to the right rear housing 10RR. The left rear wheel RWL is attached to the left rear housing 10RL. Each housing houses a hub bearing that rotatably supports each wheel. Each housing is located closer to the wheel than the suspension spring and is an unsprung part that displaces relative to the vehicle body together with the wheel in accordance with the stroke of the suspension device.

[0014] The right front housing 10FR is attached to the vehicle body via a right front suspension 20FR. The left front housing 10FL is attached to the vehicle body via a left front suspension 20FL. The right rear housing 10RR is attached to the vehicle body via a right rear suspension 20RR. The left rear housing 10RL is attached to the vehicle body via a left rear suspension 20RL. Each suspension has a suspension spring that generates a spring reaction force according to the stroke, and a damper (shock absorber) that generates a damping force according to the stroke speed. The damper is a variable damping damper whose damping force characteristics change according to commands from a control device (not shown).

[0015] The vehicle 1 is also provided with a roll rate sensor 30 and a pitch rate sensor 40. The roll rate sensor 30 is a sensor such as a vibration gyro sensor that detects the angular velocity of the roll behavior of the body of the vehicle 1. The roll behavior is a behavior in which the front and rear suspensions are in phase and the left and right suspensions stroke in opposite phase directions (left and right sway behavior). The pitch rate sensor 40 is a sensor such as a vibration gyro that detects the angular velocity of the pitch behavior of the body of the vehicle 1. The pitch behavior is a behavior in which the front and rear suspensions are in phase and the left and right suspensions stroke in the same phase direction (front and rear sway behavior).

[0016] The information presentation device 100 of the first embodiment presents information reflecting the roll behavior and pitch behavior of the vehicle body as acoustic information to a driver D accommodated in a vehicle cabin. Fig. 2 is a diagram schematically showing the system configuration of the information presentation device of the first embodiment. The information presentation device 100 vibrates the air around the ears of occupants using speakers 170 arranged in the vehicle cabin, and notifies the occupants of information reflecting the vehicle behavior by acoustic signals. The information presentation device 100 includes a waveform generation unit 110, a behavior detection unit 120, a first gain adjustment unit 130, a microphone 140, a sensing value calculation unit 150, a second gain adjustment unit 160, the speaker 170, etc.

[0017] The waveform generating unit 110 generates an excitation waveform, which is the waveform of the acoustic signal generated by the speaker 170. FIG. 3 is a diagram schematically illustrating an example of an excitation waveform in the first embodiment. In FIG. 3, the horizontal axis represents time, and the vertical axis represents voltage (amplitude). For example, as shown in FIG. 3( a), the excitation waveform can be a sine wave. Furthermore, as shown in FIG. 3( b), the excitation waveform can be a waveform in which multiple sine waves with different wavelengths are superimposed (combined). Furthermore, the excitation waveform is not limited to these and can be changed as appropriate. For example, various waveforms such as a square wave, a triangular wave, and a waveform simulating the sound of a vehicle running can be used alone or combined with other waveforms as the excitation waveform.

[0018] In the first embodiment, the frequency of the vibration waveform can be set to have a dominant frequency in the range of, for example, 100 to 400 Hz, more preferably 150 to 300 Hz. The reason for this is explained below. When the air around the occupant is vibrated, sensory receptors that detect the vibration include Merkel cells, Meissner's corpuscles, and Pacinian corpuscles. Figure 4 is a diagram schematically showing the timing of electrical pulses emitted by receptors when stimulated. In Figure 4, the horizontal axis represents time, and the vertical axis represents, from top to bottom, pressure and the electrical pulse generation state of Merkel cells, Meissner's corpuscles, and Pacinian corpuscles.

[0019] Merkel cells have a relatively slow response and correspond to direct current components. Meissner's corpuscles respond when there is a rate of change (speed) of contact pressure. Pacinian corpuscles respond to moments of transient change and are said to be the most sensitive of these receptors. Pacinian corpuscles are thought to have the best sensitivity as receptors that allow passengers to perceive minute vibrations as combined auditory and tactile information.

[0020] Figure 5 shows the frequency sensitivity distribution of Pacinian corpuscles and Meissner corpuscles. In Figure 5, the horizontal axis represents frequency and the vertical axis represents amplitude above threshold, with smaller values ​​indicating better sensitivity. As shown in Figure 5, Pacinian corpuscles exhibit good sensitivity in the range of approximately 100 to 400 Hz, and even better sensitivity in the range of 150 to 300 Hz. This range is included in the range of 20 Hz to 20 kHz, which is generally considered to be the human audible range. The dominant frequency of the excitation waveform can be set to 250 Hz, for example.

[0021] The behavior detection unit 120 detects the roll rate (angular velocity of roll behavior) and pitch rate (angular velocity of pitch behavior) of the body of the vehicle 1 based on the outputs of the roll rate sensor 30 and the pitch rate sensor 40. The behavior detection unit 120 sequentially transmits the detected roll rate and pitch rate to the first gain adjustment unit 130.

[0022] The first gain adjustment unit 130 performs the first gain adjustment, which will be described below, on the fundamental wave of the excitation waveform generated by the waveform generation unit 110. The first gain adjustment changes the gain G1, which is the output gain by which the voltage of the excitation waveform is multiplied, according to the magnitude of the detected roll rate and pitch rate.

[0023] Fig. 6 is a diagram schematically illustrating an example of gain adjustment in the first gain adjustment unit. In Fig. 6, the horizontal axis represents the absolute value of the roll rate or pitch rate, and the vertical axis represents the gain G1 by which the voltage of the excitation waveform is multiplied. The gain G1 can be configured to increase as the roll rate or pitch rate increases. Furthermore, the rate of increase of the gain G1 with respect to an increase in the roll rate or pitch rate in the first gain adjustment unit 130 can be configured to be maximum in a region where the absolute values ​​of the roll rate and pitch rate are small, and to decrease as the absolute values ​​of the roll rate and pitch rate increase.

[0024] The gain G1 in the first gain adjustment unit 130 can be calculated, for example, from the absolute values ​​of the roll rate and pitch rate using a logarithmic function. The gain G1 is expressed, for example, by the following equation 1: Gain G1=log(absolute values ​​of roll rate and pitch rate×coefficient k) (Equation 1) The coefficient k can be a value set, for example, during the development stage of the vehicle, in accordance with the characteristics of the vehicle.

[0025] The microphone 140 is a sound collecting device provided in the vehicle cabin to collect background noise within the vehicle cabin. The microphone 140 is preferably disposed in a position close to the ears of the occupants, and may be provided, for example, in the headrest of the seat. The output of the microphone 140 is transmitted to the sensing value calculation unit 150.

[0026] The sensing value calculation unit 150 extracts components in a predetermined frequency band from the background noise of the vehicle acquired by the microphone 140, and transmits the sound pressure of the extracted components as a sensing value to the second gain adjustment unit 160. Fig. 7 is a diagram schematically showing an example of the microphone output history. In Fig. 7, the horizontal axis represents time, and the vertical axis represents the sound pressure of the background noise acquired by the microphone 140.

[0027] The sensing value calculation unit 150 performs a fast Fourier transform (FFT) on the acoustic signal of the background noise acquired by the microphone 140 to convert it into the frequency domain, and then performs band-pass filtering to extract components of a predetermined frequency band. The frequency band to be extracted is set to include the dominant frequency of the excitation waveform output by the waveform generation unit 110. The sensing value calculation unit 150 sets the average sound pressure of the extracted frequency band as a sensing value to be used for the second gain adjustment.

[0028] Fig. 8 is a diagram showing an example of the correlation between the sound pressure of background noise and frequency. In Fig. 8, the horizontal axis represents frequency, and the vertical axis represents sound pressure. The band-pass filter can be configured, for example, to extract a frequency band near the dominant frequency (e.g., 250 Hz) of the excitation waveform in the waveform generating unit 110. The sound pressure in the extracted frequency band (e.g., the average value of the frequency band) is provided to the second gain adjusting unit 160 as a sensing value.

[0029] The second gain adjustment unit 160 further performs a second gain adjustment, which will be described below, on the excitation waveform after the first gain adjustment. The second gain adjustment changes the gain of the excitation waveform according to the sensed value of the cabin noise in order to adjust the output amplitude of the excitation waveform according to changes in background noise (drivetrain noise, aerodynamic noise, road noise, etc.) while the vehicle is running. The second gain adjustment unit 160 performs the second gain adjustment based on the output of the sensing value calculation unit 150.

[0030] The second gain adjustment unit 160 sets the gain G2 based on the sensing value output by the sensing value calculation unit 150. FIG. 9 is a diagram schematically illustrating an example of gain adjustment in the second gain adjustment unit. In FIG. 9, the horizontal axis represents the sensing value, and the vertical axis represents the gain G2 multiplied by the voltage of the excitation waveform. The gain G2 can be configured to increase as the sensing value increases. The gain G2 is set so that the sound pressure of the sound generated by the excitation amplitude output from the speaker 170 does not dominate over the sound pressure of background noise near the ears of the occupants. Preferably, the gain G2 is set so that the sound generated by the excitation amplitude blends in with the background noise of the vehicle and reaches a sound pressure level that the occupants can unconsciously hear.

[0031] The output value (voltage) A of the vibration waveform after the first gain adjustment and second gain adjustment described above is expressed as in Equation 2. Output value A = waveform generator output value × gain G1 × gain G2 = waveform generator output value × log (absolute value of roll rate, pitch rate × coefficient k) × gain G2 (Equation 2)

[0032] The speaker 170 is a vibration device disposed in the vehicle cabin that vibrates the air around the occupants in the vehicle cabin using the output value A to generate sound. The placement of the speaker 170 will be described in detail later. The speaker 170 may be configured to be shared with a speaker used for audio playback of an in-vehicle audio device, for example. Alternatively, a speaker 170 dedicated to the information presentation device 100 may be provided.

[0033] 10 is a diagram illustrating the layout of a vehicle interior in which the information presentation device of the first embodiment is installed. Inside the vehicle interior 200, a driver's seat 210, a passenger seat 220, a rear seat 230, an instrument panel 240, and the like are provided.

[0034] The driver's seat 210 and the passenger seat 220 are front seats located at the front of the vehicle cabin. The driver's seat 210 and the passenger seat 220 are located side by side in the vehicle width direction. In the example shown in Fig. 10, the vehicle is, as an example, a so-called right-hand drive vehicle, and the driver's seat 210 is located on the right side and the passenger seat 220 is located on the left side with respect to the center of the vehicle body. The driver's seat 210 and the passenger seat 220 each have a cushion portion on which the occupant's buttocks and thighs are placed, a seatback portion located behind the occupant's back, and a headrest portion located behind the occupant's head.

[0035] The rear seat 230 is a bench-like seat located behind the driver's seat 210 and the passenger seat 220. The rear seat 230 is capable of accommodating, for example, two passengers sitting side by side. The rear seat 230 has a cushion portion on which the passenger's buttocks and thighs are placed, a seatback portion located behind the passenger's back, and a headrest portion located behind the passenger's head. The right seating portion of the rear seat 230 is located behind the driver's seat 210, and the left seating portion is located behind the passenger seat 220.

[0036] The instrument panel 240 is provided near the front end of the vehicle interior 200 and houses, for example, an instrument panel, a ventilation / air-conditioning / heating system, an infotainment system, etc. The instrument panel 240 is disposed so as to face the occupants seated in the driver's seat 210 and the passenger seat 220.

[0037] 10, for example, four speakers 170 are provided spaced apart from each other at the front, rear, left and right of the vehicle interior 200. In the following description, the reference numerals of the speakers 170 will be given with subscripts corresponding to their positions.

[0038] The right front speaker 170FR is disposed near the right end of the instrument panel 240. The speaker 170FR is a directional speaker that is directed toward the head (ear) of an occupant seated in the driver's seat 210. The left front speaker 170FL is disposed near the left end of the instrument panel 240. The speaker 170FL is a directional speaker that is directed toward the head (ear) of an occupant seated in the passenger seat 220.

[0039] The right rear speaker 170RR is disposed in the headrest of the driver's seat 210. The speaker 170RR is a directional speaker that is directed toward the head (ear) of an occupant seated on the right side of the rear seat 230. The left rear speaker 170RL is disposed in the headrest of the passenger seat 220. The speaker 170RL is a directional speaker that is directed toward the head (ear) of an occupant seated on the left side of the rear seat 230.

[0040] The information presentation device 100 can be configured to selectively transmit acoustic information corresponding to the behavior of the vehicle body to some of the occupants in the vehicle cabin. For example, the information presentation device 100 can be configured to present information using only the right front speaker 170FR to present information to the driver D seated in the driver's seat 210. This makes it possible to effectively present information related to the behavior of the vehicle body only to the driver D without changing the ride comfort perceived by the occupants other than the driver D.

[0041] The effects of the information presentation device of the first embodiment will be described below. FIG. 11 is a graph showing the correlation between the roll rate of the vehicle and the movement of the driver's head. In FIG. 11, the horizontal axis represents the roll rate of the vehicle, and the vertical axis represents the movement of the driver's head. In the figure, data with information presentation are plotted with black dots, and data without information presentation are plotted with gray dots. As shown in FIG. 11, it can be seen that by presenting information, the movement of the occupant's head is suppressed, and the predictability of vehicle behavior for the occupant is improved.

[0042] The first embodiment described above provides the following advantages. (1) By increasing the amplitude of the excitation waveform in response to an increase in a parameter correlated with the vehicle body behavior, the vehicle body behavior can be acoustically recognized by the driver D and other occupants without changing the actual ride comfort of the vehicle. This improves drivability. (2) By using the pitch rate and roll rate of the vehicle body as parameters correlated with the vehicle body behavior, the vehicle behavior can be appropriately reflected in the information presentation using parameters that are relatively easy to obtain. (3) By presenting information to the driver D seated in the driver's seat 210 using only the right front speaker 170FR, appropriate information can be presented to the driver D, who has a high demand for understanding the vehicle behavior, while suppressing information presentation to other occupants, thereby preventing the impression of a worsened ride comfort. (4) The excitation waveform has a dominant frequency in the 100 to 400 Hz frequency band. This enables the use of Pacinian corpuscles, which are in the audible range and highly sensitive to cutaneous sensation, and improves the occupants' acoustic sound perception and cutaneous perception. (5) By adjusting the gain so that the sound pressure generated by the speaker does not dominate the background noise generated when the vehicle is running, it is possible to prevent the sound from being unpleasant to the ears of the passengers and to properly convey information to the passengers.

[0043] Second Embodiment Next, a second embodiment of an information presentation device to which the present invention is applied will be described. Components common to the first embodiment described above will be assigned the same reference numerals and explanations thereof will be omitted, and differences will be mainly described. The information presentation device of the second embodiment presents information by directly vibrating a driving operation member, such as a seat or a steering wheel, that comes into contact with the body of the occupant, instead of the speaker 170 of the first embodiment, thereby transmitting vibrations to the occupant. The second embodiment described above can also achieve the same effects as the first embodiment described above.

[0044] (Modifications) The present invention is not limited to the above-described embodiments, and various modifications and variations are possible, and these are also within the technical scope of the present invention. (1) The configurations of the information presentation device and the vehicle are not limited to the above-described embodiments, and can be modified as appropriate. For example, the hardware configuration of the information presentation device and the specific method of adjusting the gain of the excitation waveform are not limited to the configurations of the embodiments, and can be modified as appropriate. (2) In the embodiments, the roll rate and pitch rate of the vehicle body are used as parameters correlated with the vehicle behavior, but these parameters are not limited to these and can be modified as appropriate.

[0045] D Driver 1 Vehicle FWR Right front wheel FWL Left front wheel RWR Right rear wheel RWL Left rear wheel 10FR Right front housing 10FL Left front housing 10RR Right rear housing 10RL Left rear housing 20FR Right front suspension 20FL Left front suspension 20RR Right rear suspension 20RL Left rear suspension 30 Roll rate sensor 40 Pitch rate sensor 100 Information presentation device 110 Waveform generation unit 120 Behavior detection unit 130 First gain adjustment unit 140 Microphone 150 Sensing value calculation unit 160 Second gain adjustment unit 170 (170FR, 170FL, 170RR, 170RL) Speaker 200 Vehicle interior 210 Driver's seat 220 Passenger seat 230 Rear seat 240 instrument panel

Claims

1. An information presentation device installed in a vehicle having a body supported by a suspension device, comprising: a behavior detection unit that detects parameters correlated to the behavior of the body; a vibration waveform generation unit that generates a vibration waveform; a vibration unit that uses the vibration waveform to vibrate at least one of the air around an occupant and a part in contact with the occupant; and a gain adjustment unit that increases the output gain of the vibration waveform in accordance with an increase in the parameter.

2. The information display device according to claim 1, characterized in that the parameters include a parameter correlated with at least one of the pitch rate and roll rate of the vehicle body.

3. The information presentation device according to claim 1 or 2, wherein the vehicle is one in which a plurality of occupants ride, and the vibration unit applies the vibration to only some of the plurality of occupants.

4. An information display device according to claim 1 or 2, characterized in that the excitation waveform has a dominant frequency within a frequency band of 100 to 400 Hz.

5. The information presentation device according to claim 1 or 2, wherein the gain adjustment unit sets the output gain so that the sound pressure generated by the vibration of the vibration unit, at the ear of at least one passenger, does not dominate over background noise when the vehicle is running.

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