Information presentation apparatus

Abstract

[Problem] To provide an information presentation apparatus which stabilizes the time from an operation by a driver to a presentation of information. [Solution] An information presentation device 100 provided in a vehicle is configured to comprise: a parameter detection part 90 that detects a parameter θ correlated with an operation amount of a driving operation device; a vibration generation part 170 that vibrates air around an occupant; and vibration adjustment parts 130, 160 that change the magnitude of the vibration generated by the vibration generation part in accordance with the amount of change in the parameter per unit time. The information presentation apparatus is configured such that: the parameter detection part acquires the parameter at least twice within a required time that is the time required from an input of the parameter to an output of vibration; and the vibration adjustment part calculates the amount of change in the parameter by using the parameter previously acquired by the parameter detection part when the time for acquiring the parameter twice is longer than or equal to the required time.

Description

Information presentation device

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

[0002] As a technology related to outputting audio to occupants of a vehicle such as an automobile according to the vehicle's state, for example, Patent Document 1 describes a driving assistance device that provides an easy-to-recognize steering angle and steering direction, in which the steering amount of a steering wheel is indicated by a sound that changes in conjunction with the steering amount. Specifically, it describes controlling the pitch of the sound so that it becomes higher as the steering amount increases, and indicating the steering amount of the steering wheel by changing the volume, pitch, tone, sound pressure, frequency, position of the sound image, etc. Patent Document 2 describes a vehicle music generation device that easily generates music that reflects the vehicle behavior and driver operation, and includes a storage unit that stores multiple sound source loop patterns each corresponding to information based on the vehicle driver's operation or vehicle behavior, and a control unit that selects a specific sound source loop pattern from the multiple sound source loop patterns according to the information and controls output or stop of the output.

[0003] JP 2007-62706 A JP 2016-66912 A

[0004] Because there is a time response delay between the start of steering a vehicle and the actual occurrence of vehicle body behavior, such as lateral acceleration, yaw rate, and roll angle, depending on the steering situation, occupants may feel that lateral acceleration or the like occurs suddenly, and may feel uncomfortable or uneasy due to being unable to properly hold their bodies. To address this, possible solutions include reducing the yaw rate gain relative to the vehicle's steering angle or improving the occupant's hold using a seat or other device. However, reducing the yaw rate gain slows the vehicle's response, impairing the vehicle's performance and marketability. Furthermore, seat-based solutions are difficult to adapt to various occupant body types. In response to this, an information presentation device that outputs an acoustic signal in response to the driver's operation of a driving control device can improve occupants' predictability of the vehicle's behavior resulting from driving operations.

[0005] However, the effectiveness of such information presentation devices utilizing tactile vibrations and acoustic signals can be affected by the time between the driver's operation and the presentation of information. For example, if the time from operation input to output (information presentation) is delayed, not only will the effectiveness be lost, but it may also have the opposite effect, making driving more difficult. In view of the above-mentioned problems, an object of the present invention is to provide an information presentation device that stabilizes the time between the driver's operation and the presentation of information.

[0006] In order to solve the above-mentioned problems, one aspect of the present invention provides an information presentation device installed in a vehicle, the information presentation device including: a parameter detection unit that detects a parameter correlated with an operation amount of a driving operation device of the vehicle; a vibration generation unit that vibrates the air around an occupant or a member that the occupant comes into contact with; and a vibration adjustment unit that changes the magnitude of the vibration generated by the vibration generation unit according to a change amount per unit time of the parameter, wherein the parameter detection unit acquires the parameter at least twice within a required time, which is the time required from input of the parameter to output of the vibration; and, if it takes longer than the required time to acquire the parameter twice, the vibration adjustment unit calculates the change amount of the parameter using the parameter previously acquired by the parameter detection unit. In this way, if the parameter cannot be acquired twice within the required time due to the communication state of an in-vehicle LAN such as a CAN communication system, the change amount of the parameter can be calculated using the previously acquired parameter (typically the parameter acquired one time before), thereby preventing delays in the output of the information presentation device and driving difficulties.

[0007] According to another aspect of the present invention, an information presentation device is provided in a vehicle, and includes: a parameter detection unit that detects a parameter correlated with the amount of operation of a driving operation device of the vehicle; a vibration generation unit that vibrates the air around the occupant or a component that the occupant comes into contact with; and a vibration adjustment unit that changes the magnitude of the vibration generated by the vibration generation unit according to the amount of change in the parameter per unit time. The parameter detection unit acquires the parameter at least three times within a required time, which is the time required from input of the parameter to output of the vibration. If some of the parameters cannot be acquired, the vibration adjustment unit calculates the amount of change in the parameter using the other parameters acquired by the parameter detection unit. By acquiring the parameters three or more times within the required time, even if some information cannot be acquired, the amount of change in the parameter per unit time can be calculated within the required time by excluding data corresponding to the delay in acquisition. This prevents delays in the output of the information presentation device, which can cause driving difficulties.

[0008] According to another aspect of the present invention, an information presentation device is provided in a vehicle, the information presentation device comprising: a parameter detection unit that detects a parameter correlated with an operation amount of a driving operation device of the vehicle; a vibration generation unit that vibrates the air around an occupant or a member that the occupant comes into contact with; and a vibration adjustment unit that changes the magnitude of the vibration generated by the vibration generation unit according to a change amount per unit time of the parameter. The parameter detection unit acquires the parameter at least twice within a required time, which is the time required from input of the parameter to output of the vibration. If only 1 or less data points for the parameter can be acquired within the required time, the vibration adjustment unit maintains the change amount of the parameter used to set the magnitude of the vibration at a previous value. This prevents delays in the output of the information presentation device and driving difficulties. In a configuration in which the change amount of the parameter is calculated and then transmitted to a CAN or the like, if the time required to acquire the change amount exceeds the required time, the previous value can be maintained as described above.

[0009] In each of the above inventions, the vehicle control system may be configured to include a waveform storage unit that stores waveforms of interior sounds when the vehicle is traveling on a specific road surface, and an excitation waveform generation unit that causes the vibration generation unit to generate vibrations using the waveforms stored in the waveform storage unit when the vehicle is traveling on the specific road surface. This makes it possible to present natural information by generating vibrations using waveforms stored during actual traveling, and by using waveforms stored in advance, it is possible to prevent output delays compared to when waveforms are acquired each time.

[0010] In each of the above inventions, the vibration generating unit may be configured to control the timing of outputting the vibration so that the ratio between the time from the change in the parameter to the output of the vibration and the time from the change in the parameter to the occurrence of a predetermined vehicle behavior is maintained within a preset tolerance range. This makes it possible to prevent the timing of outputting the vibration from varying, which would cause discomfort, even if the response characteristics of the vehicle change depending on, for example, the operation frequency of the driver.

[0011] As described above, according to the present invention, it is possible to provide an information display device that stabilizes the time from the driver's operation to the display of information.

[0012] 1 is a diagram schematically showing the configuration of an electric power steering device of a vehicle having a first embodiment of an information presentation device to which the present invention is applied. 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 electric 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 the information presentation device of the first embodiment is provided. FIG. 11 is a diagram showing an example of a Bode plot representing a general frequency response of a vehicle. FIG. 12 is a diagram schematically showing the configuration of an autonomous driving system for a vehicle in which an information presentation device of a fifth embodiment is provided.

[0013] First Embodiment A first embodiment of an information presentation device to which the present invention is applied will now be described. The information presentation device according to the embodiment is installed in, for example, a four-wheel vehicle (e.g., an automobile such as a passenger car) in which two front wheels are steered. The vehicle is equipped with an electric power steering device that applies a steering assist force by an electric motor to a steering device that steers the front wheels.

[0014] 1 is a diagram showing a schematic configuration of an electric power steering device for a vehicle according to the first embodiment. The electric power steering device 1 includes a steering wheel 10, a steering shaft 20, an intermediate shaft 21, a pinion shaft 22, a rack shaft 30, a rack housing 40, a tie rod 50, a housing 60, a steering angle sensor 71, a torque sensor 72, an actuator unit 80, an electric power steering control unit (EPS control unit) 90, etc.

[0015] The steering wheel 10 is, for example, a circular operating member that the driver turns to input steering operations. The steering wheel 10 is disposed opposite the driver's seat in the vehicle cabin. The occupant (driver) senses the steering feeling of the vehicle from the tactile sensation (haptic sensation) presented to the fingers of the steering wheel 10.

[0016] The steering shaft 20 is a rotating shaft with one end attached to the steering wheel 10, and is a rotating shaft that presents the rotational movement of the steering wheel 10 to a rack and pinion mechanism that converts the rotational movement of the steering wheel 10 into translational movement in the vehicle width direction. An intermediate shaft 21 and a pinion shaft 22 are connected in this order to the end of the steering shaft 20 opposite to the steering wheel 10 side.

[0017] Universal joints (Cardan joints) 23, 24 that allow rotation of each shaft in a bent state are provided between the steering shaft 20 and the intermediate shaft 21, and between the intermediate shaft 21 and the pinion shaft 22. A pinion gear that meshes with a rack gear 31 of the rack shaft 30 to drive the rack shaft 30 is formed at the tip of the pinion shaft 22.

[0018] The rack shaft 30 is a columnar member arranged with its longitudinal direction (axial direction) aligned with the vehicle width direction. The rack shaft 30 is supported on the vehicle body so as to be able to translate in the vehicle width direction. A rack gear 31 that meshes with a pinion gear of the pinion shaft 22 is formed on a portion of the rack shaft 30. The rack gear 31 is driven by the pinion gear in response to rotation of the steering shaft 20, causing the rack shaft 30 to translate (move straight) along the vehicle width direction. The rack gear 31 is offset to either the left or right (usually toward the driver's seat) in the vehicle width direction. For example, if the vehicle is a so-called right-hand drive vehicle with the driver's seat located on the right front seat, the rack gear 31 is offset to the right of the center when in neutral.

[0019] The rack housing 40 is a substantially cylindrical member that houses and supports the rack shaft 30 so that it can be displaced relative to the vehicle width direction. Rack boots 41 are provided on both ends of the rack housing 40. The rack boots 41 are members that prevent foreign matter such as dust from entering the rack housing 40 while allowing relative displacement of the tie rod 50 with respect to the rack housing 40. The rack boots 41 are formed in a flexible bellows-like shape from a resin-based material such as elastomer.

[0020] The tie rod 50 is a shaft-shaped interlocking member that connects the end of the rack shaft 30 and a knuckle arm 61 of the housing 60 and rotates the housing 60 about the kingpin axis in conjunction with the translational movement of the rack shaft 30. The inner end of the tie rod 50 in the vehicle width direction is swingably connected to the end of the rack shaft 30 via a ball joint 51. The outer end of the tie rod 50 in the vehicle width direction is connected to the knuckle arm 61 of the housing 60 via a ball joint 52.

[0021] The housing (knuckle) 60 is a member that houses a hub bearing that supports the wheel W for rotation about the axle. The housing 60 has a knuckle arm 61 that protrudes forward or rearward from the axle. The housing 60 is supported for rotation about a kingpin axis, which is a predetermined rotation center axis. For example, if the vehicle's front suspension is a MacPherson strut type, the kingpin axis is an imaginary axis that connects the center of the bearing of the strut top mount and the center of the ball joint that connects the lower part of the housing 60 to the transverse link (lower arm). The housing 60 is pushed and pulled in the vehicle width direction by the rack shaft 30 via the tie rod 50, thereby rotating about the kingpin axis and steering the wheel W.

[0022] The steering angle sensor 71 is an angle encoder that detects the rotational angle position of the pinion shaft 22. The output of the steering angle sensor 71 is presented to the electric power steering control unit 90. The electric power steering control unit 90 is able to calculate the steering angle θ of the wheels W (the toe change angle associated with steering) based on the output of the steering angle sensor 71.

[0023] Torque sensor 72 is a sensor that detects torque (mainly the steering force applied by the driver) acting on pinion shaft 22. Torque sensor 72 is provided on a portion of pinion shaft 22 that is closer to intermediate shaft 21 than actuator unit 80. The output of torque sensor 72 is presented to electric power steering control unit 90.

[0024] The actuator unit 80 is a drive device that rotationally drives the pinion shaft 22 to provide power assist during manual driving and steering operation during automatic driving. The actuator unit 80 is configured with a motor 81, a gearbox 82, etc. The motor 81 is an electric actuator that generates driving force to be applied to the steering shaft 20. The rotation direction and output torque of the motor 81 are controlled by an electric power steering control unit 90. The gearbox 82 is equipped with a reduction gear train that decelerates (torque amplifies) the rotation output of the motor 81 and presents it to the pinion shaft 22.

[0025] The electric power steering (EPS) control unit 90 is a control device (motor control unit) that provides a current command value for controlling the rotation direction and output torque of the motor 81. The electric power steering control unit 90 can be configured as, for example, a microcomputer having an information processing unit such as a CPU, storage units such as RAM and ROM, an input / output interface, and a bus connecting these. The electric power steering control unit 90 can acquire information such as the outputs of the steering angle sensor 71 and the torque sensor 72, the vehicle's running speed (vehicle speed), and the operating status of other on-board electronic devices directly or via an on-board LAN such as a CAN communication system.

[0026] When the vehicle is being manually driven, the electric power steering control unit 90 sets a current command value to be given to the motor 81 based on the torque input direction and detected torque value of the torque sensor 72. The electric power steering control unit 90 is equipped with a power supply device that supplies electric power of a current value and a voltage value according to the current command value to the motor 81 via a signal line.

[0027] 2 is a diagram illustrating a system configuration of the information presentation device according to the first embodiment. The information presentation device 100 vibrates the air around the ears of occupants using speakers 170 disposed in the vehicle cabin, thereby notifying the occupants of signs of upcoming vehicle behavior via acoustic signals. The information presentation device 100 includes a waveform generation unit 110, a differential calculation unit 120, a first gain adjustment unit 130, a microphone 140, a sensing value calculation unit 150, a second gain adjustment unit 160, and the speaker 170.

[0028] 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 showing 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, for example, as shown in FIG. 3( b), the excitation waveform can be a waveform in which multiple sine waves with different wavelengths are superimposed (combined).

[0029] 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 in combination with other waveforms.

[0030] The waveform generation unit 110 also has a function of generating an excitation waveform that simulates the interior sound generated when the vehicle is actually traveling. The waveform generation unit 110 is connected to a waveform storage unit 111 and a positioning device 112. The waveform storage unit 111 has a storage medium that stores waveform data of the interior sound generated when the vehicle is traveling, which is recorded by a microphone 140 (described later). The positioning device 112 detects the current position of the vehicle using, for example, a satellite positioning system.

[0031] The waveform storage unit 111 has a function of recording the waveform data in association with the position information detected by the positioning device 112. Furthermore, when the information presentation device 100 is operating, if the vehicle is traveling on a road for which waveform data has been stored in the waveform storage unit 111, the waveform storage unit 111 supplies the waveform data obtained while traveling on the road to the waveform generation unit 110 as an excitation waveform.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The differential calculation unit 120 acquires information on the steering angle θ of the wheel W detected by the steering angle sensor 71 from the electric power steering control unit 90, and calculates a differential value Δθ (amount of change) by differentiating the information with respect to time. The differential calculation unit 120 sequentially presents the calculated differential value Δθ to the first gain adjustment unit 130.

[0036] 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 multiplied by the voltage of the excitation waveform, in accordance with the differential value (rate of change per time) of the steering angle θ of the steering device (a parameter correlated with the steering amount).

[0037] 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 derivative value Δθ of the steering angle θ of the wheel FW, 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 absolute value of the derivative value Δθ increases. Furthermore, the rate of increase of the gain G1 relative to the increase in the absolute value of the derivative value Δθ in the first gain adjustment unit 130 can be configured to be maximum in a region where the absolute value of the derivative value Δθ is small, and to decrease as the absolute value of the derivative value Δθ increases.

[0038] The gain G1 in the first gain adjustment unit 130 can be calculated, for example, from the absolute value of the differential value Δθ of the steering angle θ using a logarithmic function. The gain G1 is expressed, for example, by the following equation 1. Gain G1=log(absolute value of steering angle differential value Δθ×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 (for example, the yaw gain with respect to the steering angle θ, the center of gravity position, etc.).

[0039] 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 presented to the sensing value calculation unit 150.

[0040] 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 presents 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The output value (voltage) A of the vibration waveform after the first gain adjustment and the 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 steering angle differential value Δθ × coefficient k) × Gain G2 (Equation 2)

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] In the first embodiment, with the above configuration, when the driver performs a steering operation and a change in the steering angle θ of the wheels W occurs, a sound having an amplitude corresponding to the differential value Δθ of the steering angle θ is emitted to the occupants from the speaker 170. This sound is masked by the sound of the vehicle traveling (background noise), and therefore is difficult for the occupants to consciously recognize as sound, but it allows the occupants to unconsciously predict the occurrence of vehicle behavior accompanied by the generation of lateral acceleration or yaw rate.

[0055] In order for the information presentation device 100 to be effective, it is necessary to set the time from a driving operation (for example, a steering operation) to the presentation of information within the time it takes for the occupant to recognize the vehicle behavior. A person perceives vehicle behavior when the yaw rate or lateral jerk (acceleration of acceleration) exceeds a predetermined discrimination threshold. For example, the discrimination threshold for yaw rate is set to 0.2 deg / s, and the discrimination threshold for lateral jerk is set to 0.5 m / s^3. It is necessary to complete the acquisition, calculation, and output of operation information (for example, steering angle θ) before the behavior occurring in the vehicle exceeds the discrimination threshold.

[0056] FIG. 11 is a diagram showing an example of a Bode diagram representing a typical frequency response of a vehicle. As shown in FIG. 11, when the frequency is 0.4 Hz, the phase delay is −10.68°, which corresponds to a delay time of 74 ms. Furthermore, when the frequency is 0.7 Hz, the phase delay is −20.30°, which corresponds to a delay time of 80 ms. Therefore, when controlling the information presentation device 100, it is necessary to complete calculations and output of acoustic information (vibration) within this delay time (required time) after a change in a parameter related to driving operation (e.g., steering angle θ) (driving operation by the driver) occurs. Note that while the Bode diagram represents a delay with respect to a steady-state input, even in the transient region at the beginning of the operation, it is necessary to complete output within the delay time of the vehicle behavior in response to the operation. In this case, the delay varies depending on the characteristics of the vehicle.

[0057] In the first embodiment, the information presentation device 100 is configured to acquire data on the steering angle θ, which is the operation amount of the driving operation device, at least twice within a predetermined required time. Typically, the information presentation device 100 calculates a differential value Δθ from the data on the steering angle θ from two times, adjusts the gain of the vibration waveform, and outputs vibration. Furthermore, if the information presentation device 100 is unable to acquire data on the steering angle θ twice within the required time due to, for example, a communication error in the in-vehicle LAN, the differential calculation unit 120 of the information presentation device 100 calculates the differential value Δθ of the steering angle θ using other data on the steering angle θ that was previously (immediately) acquired.

[0058] Furthermore, in order to enable the above-described information presentation without delay, it is effective to prepare the excitation waveform in advance. To avoid giving a sense of discomfort to the occupants, it is desirable to acquire and output (play back) the waveform when the vehicle is actually running, but this leads to an output delay. Therefore, in the first embodiment, a system is provided in which pre-acquired waveform data is recorded and saved as a waveform file in a waveform storage unit 111 having a memory function, and the file is used to present and output information in accordance with operation information, thereby using a more natural waveform and not impairing the effectiveness of the information presentation.

[0059] According to the first embodiment described above, the following effects can be obtained. (1) For example, when a parameter (steering angle θ) cannot be acquired twice within the required time due to the communication state of an in-vehicle LAN or the like, by calculating the amount of change in the parameter (differential value Δθ) using the parameter acquired previously (typically the previous one), it is possible to prevent delays in the output of the information presentation device and the resulting difficulty in driving. (2) By using a waveform based on interior sounds recorded by microphone 140 during actual driving as an excitation waveform, it is possible to present information in a natural manner, and by using a waveform stored in advance, it is possible to prevent output delays compared to when waveforms are acquired each time.

[0060] Second Embodiment Next, a second embodiment of an information presentation device to which the present invention is applied will be described. In each embodiment described below, parts that are substantially the same as those in the previous embodiments will be assigned the same reference numerals, and descriptions thereof will be omitted, with differences being mainly described. The information presentation device of the second embodiment is characterized in that it acquires information on a parameter (steering angle θ) correlated with a driving operation amount three or more times within a required time, and even if some of the information cannot be acquired, it excludes data corresponding to the acquisition delay, calculates the amount of change in the parameter within the required time, and outputs vibration. The second embodiment described above can also achieve effects similar to those of the first embodiment described above.

[0061] Third Embodiment Next, a third embodiment of an information presentation device to which the present invention is applied will be described. The information presentation device of the third embodiment is characterized in that, when information on a parameter (steering angle θ) correlated with a driving operation amount is acquired with a value of 1 or less within the required time, the change amount (Δθ) of the parameter used to set the vibration magnitude is maintained at the previous value. According to the third embodiment described above, when parameter data of 1 or less is acquired within the required time, it is possible to prevent delays in the output of the information presentation device and the resulting difficulty in driving.

[0062] Next, a fourth embodiment of an information presentation device to which the present invention is applied will be described. The information presentation device of the fourth embodiment estimates the vehicle's response characteristics from the frequency of the driver's driving operation, etc., and sequentially estimates the time from the operation input to the occurrence of vehicle behavior that exceeds the occupant's discrimination threshold. In the first embodiment, the information presentation device 100 controls the timing of vibration output so that the ratio between the time from a change in a parameter (e.g., steering angle θ) to the output of vibration from the speaker 170 and the time from the change in the parameter to the occurrence of vehicle behavior that exceeds the discrimination threshold is maintained within a predetermined tolerance range. According to the fourth embodiment described above, even if the vehicle's response characteristics change depending on, for example, the driver's operation frequency, it is possible to prevent the timing of vibration output from varying, which would cause discomfort.

[0063] Fifth Embodiment Next, a fifth embodiment of an information presentation device to which the present invention is applied will be described. In the fifth embodiment, a vehicle has an automatic driving function that independently performs steering operations, acceleration / deceleration operations, and the like without relying on driving operations by a driver.

[0064] 12 is a diagram schematically illustrating the configuration of an autonomous driving system for a vehicle equipped with an information presentation device according to the fifth embodiment. The autonomous driving system 300 includes an autonomous driving control unit 310, an engine control unit 320, a transmission control unit 330, a brake control unit 340, and the like, in addition to the electric power steering control unit 90 described above. Each of these units includes a microcomputer having an information processing unit such as a CPU, a storage unit such as a RAM or a ROM, an input / output interface, and a bus connecting these units. The units are connected to each other via an on-board LAN such as a CAN communication system or directly, allowing them to communicate with each other.

[0065] The autonomous driving control unit 310 recognizes the environment around the vehicle using various sensors, such as a stereo camera device, a millimeter-wave radar device, and a laser scanner device, as well as a high-precision 3D map. Based on the recognized environment, the autonomous driving control unit 310 generates an autonomous driving scenario including information on the vehicle's driving line, speed, etc. Based on the autonomous driving scenario, the autonomous driving control unit 310 issues instructions to the electric power steering control unit 90, the engine control unit 320, the transmission control unit 330, and the brake control unit 340 to control the steering and acceleration / deceleration of the vehicle.

[0066] The electric power steering control unit 90 controls the actuator unit 80 in accordance with a required steering angle instructed by the automatic driving control unit 310, instead of a steering input from the driver as in the first embodiment, to steer the wheels W.

[0067] The engine control unit 320 comprehensively controls the engine, which is the power source for driving the vehicle, and its accessories. The engine control unit 320 controls the output of the engine so that the torque actually generated by the engine matches the required torque specified by the automatic driving control unit 310.

[0068] The transmission control unit 330 comprehensively controls the transmission, which changes the speed (speeds down or speeds up) of the rotation of the engine output shaft, and its accessories. In response to instructions from the automatic driving control unit 310, the transmission control unit 330 switches between the driving range and the non-driving range, switches between forward and reverse, and changes gears when driving forward (changing the gear ratio).

[0069] The brake control unit 340 controls the braking force of the hydraulic service brakes provided on each wheel of the vehicle. The brake control unit 340 adjusts the brake fluid pressure supplied to the wheel cylinders of each wheel in accordance with the required braking force instructed by the automatic driving control unit 310, thereby generating the required braking force.

[0070] In the fifth embodiment, even during autonomous driving when the driver basically does not perform steering operation, the required steering angle presented to the electric power steering control unit 90 from the autonomous driving control unit 310 is used as an input to the information presentation device 100 (a parameter correlated with the steering angle of the steering device), and the first gain adjustment is performed based on the derivative value thereof. According to the fifth embodiment described above, even in an autonomously driven vehicle, at the start of steering due to autonomous driving control, a sound is generated according to the absolute value of the derivative value of the steering angle, making it possible for occupants to predict the occurrence of vehicle behavior accompanied by the occurrence of lateral acceleration, yaw rate, roll angle, etc., and preventing occupants from feeling abruptness in the vehicle behavior.

[0071] (Modifications) The present invention is not limited to the above-described embodiments, and various modifications and variations are possible, all of which are 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 for 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 steering angle (the actual steering angle detected by the steering angle sensor or the requested steering angle in automatic driving control) is used as a parameter correlated with the steering amount of the steering device, but this parameter is not limited to this and can be modified as appropriate. For example, the parameter may be at least one of the steering torque (input torque) input by the driver, the operating amount of an actuator that steers the wheels (for example, the rotation amount of the motor), and the output instruction value to the actuator. (3) The present invention is not limited to those in which an operating member such as a steering wheel is mechanically connected to a steering mechanism such as a steering gearbox, as in the embodiments, but can also be applied to vehicles having a steer-by-wire steering device in which the steering wheel and the steering mechanism are not mechanically connected. In this case, the actual steering angle of the front wheels or the state of the steering mechanism (for example, the rotational angle position of the pinion gear or the movement amount of the rack shaft) can be used as a parameter correlated with the steering amount of the steering device. (4) In each embodiment, the background noise level of the vehicle is acquired using a microphone as an example, but this is not limited to this and the background noise level may be acquired using other methods. For example, the background noise level may be estimated based on the acceleration of the unsprung part of the vehicle, which correlates with input from the road surface, or the output value of a torque sensor of the steering device (torsion bar torque). (5) In the first embodiment, the driver's driving operation device uses, for example, the steering amount and steering torque as parameters indicating the amount of operation of the steering device. However, the present invention is not limited to this and other values ​​may be used as parameters. For example, the amount of operation of the accelerator pedal or a required torque set based on this amount of operation may be used as a parameter indicating the amount of operation, and sound (vibration) may be generated according to the amount of change in the parameters.Furthermore, the amount of operation of the brake pedal or a target braking force set based on this amount of operation may be used as a parameter indicating the amount of operation, and sound (vibration) may be generated according to the amount of change in the parameter. (6) In the third embodiment, the information presentation device acquires data related to the parameter (steering angle) from a CAN or the like and calculates the amount of change (differential value), but the present invention is not limited to this. The amount of change in the parameter may be calculated on the vehicle side (outside the information presentation device) and then transmitted to the information presentation device via a CAN or the like. In this case, if the time required to acquire the amount of change becomes longer than the required time, the previous value (typically the value immediately preceding) may be retained, as in the third embodiment.

[0072] REFERENCE SIGNS LIST 1 Electric power steering device W Wheel 10 Steering wheel 20 Steering shaft 21 Intermediate shaft 22 Pinion shaft 23, 24 Universal joint 30 Rack shaft 31 Rack gear 40 Rack housing 41 Rack boot 50 Tie rod 51, 52 Ball joint 60 Housing 71 Steering angle sensor 72 Torque sensor 80 Actuator unit 81 Motor 82 Gear box 90 Electric power steering control unit 100 Information presentation device 110 Waveform generation unit 111 Waveform storage unit 112 Positioning device 120 Differential calculation 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 300 Automated driving system 310 Automated driving control unit 320 Engine control unit 330 Transmission control unit 340 Brake control unit

Claims

1. An information presentation device installed in a vehicle, comprising: a parameter detection unit that detects a parameter correlated to an amount of operation of a driving operation device of the vehicle; a vibration generation unit that vibrates the air around an occupant or a member with which the occupant comes into contact; and a vibration adjustment unit that changes the magnitude of the vibration generated by the vibration generation unit in accordance with an amount of change in the parameter per unit time, wherein the parameter detection unit obtains the parameter at least twice within a required time, which is the time required from input of the parameter to output of the vibration, and when it takes more than the required time to obtain the parameter twice, the vibration adjustment unit calculates the amount of change in the parameter using the parameter previously obtained by the parameter detection unit.

2. An information presentation device installed in a vehicle, comprising: a parameter detection unit that detects a parameter correlated to the amount of operation of a driving operation device of the vehicle; a vibration generation unit that vibrates the air around the occupant or a member with which the occupant comes into contact; and a vibration adjustment unit that changes the magnitude of the vibration generated by the vibration generation unit in accordance with the amount of change in the parameter per unit time, wherein the parameter detection unit obtains the parameter at least three times within a required time that is the time required from input of the parameter to output of the vibration, and when it is impossible to obtain some of the parameters, the vibration adjustment unit calculates the amount of change in the parameter using the other parameters obtained by the parameter detection unit.

3. An information presentation device installed in a vehicle, comprising: a parameter detection unit that detects a parameter correlated to the amount of operation of a driving operation device of the vehicle; a vibration generation unit that vibrates the air around the occupant or a member with which the occupant comes into contact; and a vibration adjustment unit that changes the magnitude of the vibration generated by the vibration generation unit in accordance with the amount of change in the parameter per unit time, wherein the parameter detection unit obtains the parameter at least twice within a required time, which is the time required from input of the parameter to output of the vibration, and the vibration adjustment unit maintains the amount of change in the parameter used to set the magnitude of the vibration at a previous value when it is only possible to obtain one or less pieces of data for the parameter within the required time.

4. An information presentation device as claimed in any one of claims 1 to 3, characterized in that it comprises: a waveform storage unit that stores waveforms of interior sounds when the vehicle is running on a specific road surface; and a vibration waveform generation unit that generates vibrations in the vibration generating unit with the waveform stored in the waveform storage unit when the vehicle is running on the specific road surface.

5. An information presentation device as claimed in any one of claims 1 to 3, characterized in that the vibration generating unit controls the timing of the output of the vibration so that the ratio between the time from the change in the parameter to the output of the vibration and the time from the change in the parameter to the occurrence of a specified vehicle behavior is maintained within a preset tolerance range.

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