Information transmission device

Abstract

The invention provides an information transmission device which improves the predictability of an occupant for a behavior caused by steering of a vehicle. An information transmission device (100) provided in a vehicle having a steering device (1) that steers wheels is configured to comprise: a parameter detection unit (71) that detects a parameter ([theta]) relating to the steering amount of the steering device; an excitation waveform generation unit (110) that generates an excitation waveform; an excitation unit (170) that excites the air around the occupant using the excitation waveform; and a gain adjustment unit (130) that increases the output gain of the excitation waveform in accordance with an increase in the absolute value of the differential value ([delta] [theta]) of the parameter.

Description

Technical Field

[0001] The present invention relates to an information transmitting device for transmitting information related to the behavior of a vehicle to an occupant of a vehicle. Background Art

[0002] In vehicles such as automobiles, as a technology related to outputting sounds to passengers according to the state of the vehicle, for example, Patent Document 1 describes a method of indicating the steering amount of a steering wheel by sound that changes in conjunction with the steering amount in order to provide a driving assistance device that can easily identify a steering angle and a steering direction.

[0003] Specifically, it records the situation where the sound level becomes higher as the steering amount increases, and the situation where the intensity, pitch, timbre, sound pressure, frequency, position of the sound image, etc. of the sound are changed to indicate the steering amount of the steering wheel.

[0004] Patent document 2 describes a vehicle music generating device that simply generates music that reflects the behavior of a vehicle and / or the operation of a driver, and comprises: a storage unit that stores a plurality of sound source cycle patterns corresponding to respective information based on the operation of the driver of the vehicle or the behavior of the vehicle; and a control unit that selects a specific sound source cycle pattern from the plurality of sound source cycle patterns based on the respective information, and controls the output or stop of the output.

[0005] Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2007-62706 Patent Document 2: Japanese Patent Application Publication No. 2016-66912 Summary of the invention

[0006] Technical issues Since there is a time response delay from the start of vehicle steering to the actual vehicle body behavior, lateral acceleration, yaw rate, roll angle, etc., depending on the conditions of the steering action, the occupants may sometimes feel discomfort and / or uneasiness due to feeling that lateral acceleration is suddenly generated, or that they are unable to properly maintain their bodies.

[0007] On the other hand, measures such as reducing the yaw rate gain with respect to the steering angle of the vehicle and improving the occupant's holding performance by seats and the like are also considered.

[0008] However, if the yaw rate gain is reduced, the responsiveness of the vehicle will become slow, and the performance and commercial value of the vehicle will be impaired. In addition, it is difficult to appropriately respond to occupants of various body shapes using measures for seats.

[0009] In view of the above-mentioned problems, an object of the present invention is to provide an information transmission device that improves the predictability of the occupant with respect to the behavior caused by the turning of the vehicle.

[0010] Technical Solution In order to solve the above-mentioned problems, an information transmission device of one embodiment of the present invention is characterized in that it is arranged in a vehicle having a steering device for steering wheels, and the information transmission device comprises: a parameter detection unit, which detects a parameter related to the steering amount of the steering device; an excitation waveform generation unit, which generates an excitation waveform; an excitation unit, which uses the excitation waveform to vibrate the air around the occupant; and a gain adjustment unit, which increases the output gain of the excitation waveform in accordance with the increase in the absolute value of the differential value of the parameter.

[0011] Accordingly, by generating a sound whose sound pressure increases in accordance with the increase in the absolute value of the differential value of a parameter related to the steering amount of the steering device (so-called steering speed), it is possible to use the sound to make the occupants anticipate the occurrence of behavior in the early stage of steering before the vehicle actually generates lateral acceleration, yaw rate, roll angle, etc.

[0012] This improves the predictability of the vehicle behavior by the occupants, and prevents the occupants from feeling a sense of abruptness regarding the vehicle behavior.

[0013] In the present invention, the excitation waveform can be configured to have a main frequency within a frequency band of 100 to 400 Hz.

[0014] This allows the use of Pacinian corpuscles or the like that are highly sensitive in the audible range and highly sensitive in terms of skin sensation, thereby improving the perception of sound and skin sensation of the occupant. Therefore, information can be more reliably transmitted to the occupant.

[0015] Here, more preferably, by setting the main frequency in the frequency band of 150 to 300 Hz, a better region of receptor sensitivity can be used, thereby promoting the above-mentioned effect.

[0016] In the present invention, the increase rate of the output gain in the gain adjustment unit with respect to the increase in the absolute value of the differential value can be configured such that the absolute value of the differential value becomes maximum in a small region and decreases in accordance with the increase in the absolute value of the differential value.

[0017] According to this, a large output gain can be set even in a region where the absolute value of the differential value is relatively small, and information can be appropriately transmitted to the occupant even in the initial stage of steering when the steering angle and the steering speed are small.

[0018] Furthermore, in a region where the absolute value of the differential value is large, it is possible to prevent the output gain from becoming excessively large.

[0019] For example, the output gain can be set based on a logarithmic function of the absolute value of the differential value.

[0020] In the present invention, the gain adjustment unit may be configured to set the output gain so that the sound pressure generated by the excitation of the excitation unit is not noticeable at the ear of at least one occupant relative to background noise during travel of the vehicle.

[0021] According to this, by making the sound generated by the excitation of the excitation unit buried in the background noise of the vehicle, it is possible to prevent the passengers from feeling the harshness and to convey information appropriately.

[0022] In the present invention, the parameter may include at least one of a steering angle of the steering device, an input torque to the steering device, an operation amount of an actuator for steering the wheels, and an output instruction value to the actuator.

[0023] According to this, any ordinary vehicle can appropriately grasp the steering amount of the steering device using easily detectable parameters.

[0024] Technical Effects As described above, according to the present invention, it is possible to provide an information transmission device that improves the predictability of the occupant with respect to the behavior caused by the turning of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a diagram schematically showing the configuration of an electric power steering device of a vehicle having an embodiment to which the information transmission device of the present invention is applied.

[0026] Figure 2 It is a diagram schematically showing the system configuration of the information transmission device according to the first embodiment.

[0027] Figure 3 It is a diagram schematically showing an example of an excitation waveform in the first embodiment.

[0028] Figure 4 It is a diagram schematically showing the timing of electrical pulses emitted by a receptor when stimulated.

[0029] Figure 5 Graphs showing the distribution of the sensitivity of Pacinian corpuscles and Meissner corpuscles with respect to frequency.

[0030] Figure 6 This is a diagram schematically showing an example of gain adjustment by the first gain adjustment unit according to the first embodiment.

[0031] Figure 7 This is a diagram schematically showing an example of the output history of the microphone in the first embodiment.

[0032] Figure 8 This is a diagram showing an example of the relationship between the sound pressure of background noise and the frequency in the first embodiment.

[0033] Fig. 9 This is a diagram schematically showing an example of gain adjustment by the second gain adjustment unit according to the first embodiment.

[0034] Fig.10 It is a diagram schematically showing the arrangement in the cabin of a vehicle in which the information transmission device according to the first embodiment is installed.

[0035] Fig.11 It is a diagram schematically showing a configuration of an automatic driving system of a vehicle provided with a second embodiment of the information transmission device to which the present invention is applied.

[0036] Explanation of symbols DETAILED DESCRIPTION

[0037] <First embodiment> Hereinafter, a first embodiment of an information transmission device to which the present invention is applied will be described.

[0038] The information transmission device according to the embodiment is provided in, for example, a four-wheel vehicle (for example, an automobile such as a passenger car) in which two front wheels are steered (turned).

[0039] The vehicle includes an electric power steering device that applies a steering assist force to a steering device for steering the front wheels using an electric motor.

[0040] Figure 1 It is a diagram schematically showing the configuration of an electric power steering system for a vehicle according to the first embodiment.

[0041] 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 , and the like.

[0042] The steering wheel 10 is, for example, an annular operation member that is rotated by the driver to input a steering operation.

[0043] The steering wheel 10 is arranged in the vehicle cabin so as to face the driver's seat.

[0044] The occupant (driver) senses the steering feeling (steering feel) of the vehicle based on the tactile feeling (tactile sense) transmitted from the steering wheel 10 to the fingers.

[0045] The steering shaft 20 is a rotating shaft having one end mounted to the steering wheel 10 and transmitting the rotation of the steering wheel 10 to a rack and pinion mechanism that converts the rotation of the steering wheel 10 into a translational motion in the vehicle width direction.

[0046] An intermediate shaft 21 and a pinion shaft 22 are sequentially connected to the end portion of the steering shaft 20 on the opposite side to the steering wheel 10 side.

[0047] Universal joints 23 and 24 capable of transmitting rotation while the shafts are bent are provided between the steering shaft 20 and the intermediate shaft 21 , and between the intermediate shaft 21 and the pinion shaft 22 , respectively.

[0048] A pinion gear for driving the rack shaft 30 so as to mesh with the rack gear 31 of the rack shaft 30 is formed at the front end portion of the pinion shaft 22 .

[0049] The rack shaft 30 is a columnar member disposed such that the longitudinal direction (axial direction) extends along the vehicle width direction.

[0050] The rack shaft 30 is supported so as to be translatably movable in the vehicle width direction relative to the vehicle body.

[0051] A rack gear 31 that meshes with the pinion gear of the pinion shaft 22 is formed at a portion of the rack shaft 30 .

[0052] The rack shaft 30 drives the rack gear 31 by the pinion gear according to the rotation of the steering shaft 20 , so that the rack shaft 30 translates (moves straight) in the vehicle width direction.

[0053] The rack gear 31 is disposed so as to be offset to either the left or right side (usually, the driver's seat side) in the vehicle width direction.

[0054] For example, when the vehicle is a so-called right-hand drive vehicle in which the right front seat is the driver's seat, the rack and pinion 31 is arranged to be offset to the right from the center in the neutral position.

[0055] The rack housing 40 is a substantially cylindrical member that supports and accommodates the rack shaft 30 so that the rack shaft 30 can be relatively displaced in the vehicle width direction.

[0056] Rack housings 41 are provided at both ends of the rack housing 40 .

[0057] The rack housing 41 is a member that allows the tie rod 50 to be displaced relative to the rack housing 40 and prevents foreign matter such as dust from entering the rack housing 40 .

[0058] The rack housing 41 is formed of a resin material such as an elastomer into a flexible bellows shape.

[0059] The tie rod 50 is a shaft-shaped linkage member that connects the end of the rack shaft 30 to the 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 .

[0060] An inner end portion of the tie rod 50 in the vehicle width direction is swingably connected to an end portion of the rack shaft 30 via a ball joint 51 .

[0061] The vehicle width direction outer side end portion of the tie rod 50 is connected to the knuckle arm 61 of the housing 60 via a ball joint 52 .

[0062] The housing (knuckle) 60 is a member that accommodates a hub bearing that supports the wheel W so as to be rotatable about the axle.

[0063] The housing 60 includes a knuckle arm 61 formed to protrude toward the front side or the rear side with respect to the axle.

[0064] The housing 60 is supported so as to be rotatable about a kingpin axis serving as a predetermined rotation center axis.

[0065] For example, when the front suspension of the vehicle is a MacPherson strut type, the kingpin axis is a virtual axis connecting the bearing center of the strut top bracket and the center of the ball joint connecting the lower part of the housing 60 and the transverse link (lower arm).

[0066] 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 wheels W.

[0067] The steering angle sensor 71 is an angle encoder that detects the rotation angle position of the pinion shaft 22 .

[0068] The output of the steering angle sensor 71 is transmitted to the electric power steering control unit 90 .

[0069] The electric power steering control unit 90 can calculate the steering angle (toe angle change angle associated with steering) θ of the wheels W based on the output of the steering angle sensor 71 .

[0070] The torque sensor 72 is a sensor that detects torque (mainly based on the steering force of the driver) acting on the pinion shaft 22 .

[0071] The torque sensor 72 is provided at a portion of the pinion shaft 22 that is closer to the intermediate shaft 21 than the actuator unit 80 .

[0072] The output of the torque sensor 72 is transmitted to the electric power steering control unit 90 .

[0073] The actuator unit 80 is a driving device that rotationally drives the pinion shaft 22 to perform power assist during manual driving and steering operation during automatic driving.

[0074] The actuator unit 80 is configured to include a motor 81 , a gear box 82 , and the like.

[0075] The motor 81 is an electric actuator that generates a driving force to be applied to the steering shaft 20 .

[0076] The rotation direction and output torque of the motor 81 are controlled by the electric power steering control unit 90 .

[0077] The gear box 82 includes a reduction gear train that reduces the speed (amplifies the torque) of the rotation output of the motor 81 and transmits the result to the pinion shaft 22 .

[0078] The electric power steering (EPS) control unit 90 is a control device (motor control unit) that provides a current instruction value for controlling the rotation direction and output torque of the motor 81 .

[0079] The electric power steering control unit 90 can be configured as, for example, a microcomputer including an information processing unit such as a CPU, a storage unit such as a RAM and / or a ROM, an input / output interface, and a bus connecting these.

[0080] The electric power steering control unit 90 can obtain information such as the output of the steering angle sensor 71 and the torque sensor 72 , the vehicle's running speed (vehicle speed), and the operating status of other vehicle-mounted electronic devices via an in-vehicle LAN such as a CAN communication system or directly.

[0081] The electric power steering control unit 90 sets a current instruction value to be supplied to the motor 81 based on the torque input direction and the detected torque value of the torque sensor 72 when the vehicle is manually driven.

[0082] The electric power steering control unit 90 includes a power supply device that supplies electric power having a current value and a voltage value corresponding to the current instruction value to the motor 81 via a signal line.

[0083] Figure 2 It is a diagram schematically showing the system configuration of the information transmission device according to the first embodiment.

[0084] The information transmission device 100 vibrates the air around the ears of the occupant using a speaker 170 disposed in the vehicle cabin, thereby notifying the occupant of a precursor to the occurrence of a vehicle behavior using an acoustic signal.

[0085] The information transmission device 100 includes a waveform generation unit 110 , a differential operation unit 120 , a first gain adjustment unit 130 , a microphone 140 , a sensing value operation unit 150 , a second gain adjustment unit 160 , a speaker 170 , and the like.

[0086] The waveform generation unit 110 generates an excitation waveform which is a waveform of an acoustic signal generated by the speaker 170 .

[0087] Figure 3 It is a diagram schematically showing an example of an excitation waveform in the first embodiment.

[0088] exist Figure 3 In the figure, the horizontal axis represents time and the vertical axis represents voltage (amplitude).

[0089] For example Figure 3 As shown in (a) of FIG. 8 , the excitation waveform can be set to a sine wave.

[0090] In addition, for example Figure 3 As shown in (b) of FIG. 8 , the excitation waveform can be a waveform obtained by superimposing (combining) a plurality of sinusoidal waves having different wavelengths.

[0091] In addition, the excitation waveform is not limited to these, and can be changed appropriately.

[0092] For example, various waveforms such as rectangular waves, triangular waves, and waveforms simulating the sound of a vehicle running can be used alone as the excitation waveform, or various waveforms such as rectangular waves, triangular waves, and waveforms simulating the sound of a vehicle running can be combined with other waveforms and used.

[0093] In the first embodiment, the frequency of the excitation waveform can be set to have a main frequency in the range of, for example, 100 to 400 Hz, more preferably, 150 to 300 Hz.

[0094] The reason is described below.

[0095] As sensory receptors that sense vibration when the air around the occupant is excited, there are Merkel cells, Meissner corpuscles, Pacinian corpuscles, and the like.

[0096] Figure 4 This is a diagram schematically showing the timing of electrical pulses emitted by a receptor when stimulated.

[0097] exist Figure 4 In the figure, the horizontal axis represents time, and the vertical axis represents pressure, and the electrical impulse generation states of Merkel cells, Meissner corpuscles, and Pacinian corpuscles, in order from the upper row.

[0098] The response of Merkel cells is relatively slow, corresponding to the DC component.

[0099] Meissner corpuscles correspond to the rate of change (velocity) of contact pressure when they are produced.

[0100] Pacinian corpuscles correspond to the instant of transient change and have the highest sensitivity among these receptors.

[0101] As a receptor through which passengers perceive tiny vibrations as a combination of auditory and tactile information, Pacinian corpuscles are believed to have the highest sensitivity.

[0102] Figure 5 Graphs showing the distribution of the sensitivity of Pacinian corpuscles and Meissner corpuscles with respect to frequency.

[0103] exist Figure 5 In FIG. 1 , the horizontal axis represents the frequency and the vertical axis represents the amplitude at the threshold value, and it is shown that the smaller the value, the better the sensitivity.

[0104] like Figure 5 As shown, the Pacinian corpuscles exhibit good sensitivity in the region around 100 to 400 Hz, and particularly exhibit better sensitivity in the region between 150 and 300 Hz.

[0105] Such an area is included in the range of 20 Hz to 20 kHz which is generally set as the audible range of humans.

[0106] As an example, the main frequency of the excitation waveform can be set to 250 Hz.

[0107] The differential calculation unit 120 obtains information on the steering angle θ of the wheels W detected by the steering angle sensor 71 from the electric power steering control unit 90 , and calculates a time-differentiated differential value Δθ.

[0108] The differential calculation unit 120 transmits the calculated differential values ​​Δθ to the first gain adjustment unit 130 one by one.

[0109] The first gain adjustment unit 130 performs a first gain adjustment, which will be described below, on the fundamental wave of the excitation waveform generated by the waveform generation unit 110 .

[0110] The first gain adjustment changes the gain G1 which is an output gain obtained by multiplying the voltage of the excitation waveform according to the differential value (rate of change per unit time) of the steering angle θ (a parameter related to the steering amount) of the steering device.

[0111] Figure 6 FIG. 1 is a diagram schematically showing an example of gain adjustment performed by the first gain adjustment unit.

[0112] exist Figure 6 In FIG. 5 , the horizontal axis represents the absolute value of the differential value Δθ of the steering angle θ of the wheel FW, and the vertical axis represents the gain G1 multiplied by the voltage of the excitation waveform.

[0113] The gain G1 can be configured to increase in accordance with an increase in the absolute value of the differential value Δθ.

[0114] Furthermore, the increase rate of the gain G1 in the first gain adjustment unit 130 with respect to the increase in the absolute value of the differential value Δθ can be configured to be maximum in a region where the absolute value of the differential value Δθ is small and to decrease in accordance with the increase in the absolute value of the differential value Δθ.

[0115] For example, the gain G1 in the first gain adjustment unit 130 can be calculated from the absolute value of the differential value Δθ of the steering angle θ using a logarithmic function.

[0116] The gain G1 is expressed by the following equation 1, for example.

[0117] Gain G1 = log (absolute value of steering angle differential value Δθ × coefficient k) (Formula 1) The coefficient k can be set to a value that is set, for example, at a vehicle development stage in accordance with the characteristics of the vehicle (for example, the yaw gain with respect to the steering angle θ, the position of the center of gravity, and the like).

[0118] The microphone 140 is a sound collecting device that is disposed in the vehicle compartment and collects background noise in the vehicle compartment.

[0119] Microphone 140 is preferably disposed at a position close to the ear of the occupant, and can be configured to be provided on a headrest portion of a seat, for example.

[0120] The output of the microphone 140 is transmitted to the sensing value calculation unit 150 .

[0121] The sensing value calculation unit 150 extracts a component of a predetermined frequency band from the background noise of the vehicle acquired by the microphone 140 , and transmits the sound pressure of the extracted component to the second gain adjustment unit 160 as a sensing value.

[0122] Figure 7 This is a diagram schematically showing an example of the output history of a microphone.

[0123] exist Figure 7 In FIG. 1 , the horizontal axis represents time, and the vertical axis represents the sound pressure of the background noise acquired by the microphone 140 .

[0124] The sensing value calculation unit 150 performs a fast Fourier transform (FFT) process on the sound signal of the background noise acquired by the microphone 140 to convert the sound signal into a frequency domain, and further performs a bandpass filter process to extract a component of a predetermined frequency band.

[0125] The extracted frequency band is set to include the main frequency of the excitation waveform output by the waveform generation unit 110 .

[0126] The sensing value calculation unit 150 sets the average sound pressure of the extracted frequency band as the sensing value used in the second gain adjustment.

[0127] Figure 8This is a diagram showing an example of the relationship between the sound pressure and frequency of background noise.

[0128] exist Figure 8 In the figure, the horizontal axis represents frequency and the vertical axis represents sound pressure.

[0129] The bandpass filter can be configured to extract, for example, a frequency band around the main frequency (250 Hz as an example) of the excitation waveform in the waveform generation unit 110 .

[0130] The sound pressure in the extracted frequency band (as an example, the average value of the frequency band) is provided to the second gain adjustment unit 160 as a sensing value.

[0131] 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.

[0132] Since the second gain adjustment adjusts the output amplitude of the excitation waveform in accordance with the change of background noise (drive system noise, aerodynamic noise, road noise, etc.) when the vehicle is running, the gain of the excitation waveform changes in accordance with the sensed value of the noise in the vehicle cabin.

[0133] The second gain adjustment unit 160 performs second gain adjustment based on the output of the sensing value calculation unit 150 .

[0134] The second gain adjustment unit 160 sets the gain G2 based on the sensing value output by the sensing value calculation unit 150 .

[0135] Fig. 9 FIG. 1 is a diagram schematically showing an example of gain adjustment performed by the second gain adjustment unit.

[0136] exist Fig. 9 In FIG. 1 , the horizontal axis represents the sensed value, and the vertical axis represents the gain G2 multiplied by the voltage of the excitation waveform.

[0137] The gain G2 can be configured to increase in accordance with an increase in the sensed value.

[0138] Gain G2 is set so that the sound pressure of the sound output from speaker 170 based on the excitation amplitude is not noticeable relative to the sound pressure of the background noise near the ears of the occupant.

[0139] Preferably, the gain G2 may be set so that the sound based on the excitation amplitude mixes into the background noise of the vehicle and reaches a sound pressure level that the occupant can hear unconsciously.

[0140] The output value (voltage) A of the excitation waveform after the first gain adjustment and the second gain adjustment described above is expressed as Equation 2.

[0141] Output value A = waveform generation unit output value × gain G1 × gain G2 = waveform generation unit output value × log (absolute value of steering angle differential value Δθ × coefficient k) × Gain G2 (Equation 2) Speaker 170 is a vibration device that is disposed in the vehicle cabin and uses output value A to vibrate the air around the occupants in the vehicle cabin to generate sound.

[0142] The arrangement of the speaker 170 will be described in detail later.

[0143] Speaker 170 may be configured to be shared with a speaker used for sound reproduction of a car audio system, for example.

[0144] In addition, the information delivery device 100 may be provided with a dedicated speaker 170 .

[0145] Fig.10 It is a diagram schematically showing the arrangement in the cabin of a vehicle in which the information transmission device according to the first embodiment is installed.

[0146] Inside the vehicle cabin 200 , a driver's seat 210 , a passenger seat 220 , a rear seat 230 , an instrument panel 240 , and the like are provided.

[0147] The driver's seat 210 and the passenger seat 220 are front seats provided at the front of the vehicle compartment.

[0148] The driver's seat 210 and the passenger seat 220 are provided in parallel with the vehicle width direction.

[0149] exist Fig.10 In the illustrated example, the vehicle is a so-called right-hand drive vehicle as an example, and the driver's seat 210 is provided on the right side and the passenger seat 220 is provided on the left side with respect to the left-right center of the vehicle body.

[0150] The driver's seat 210 and the passenger's seat 220 each include a cushion portion for placing the occupant's buttocks and thighs, a seat back portion disposed behind the occupant's back, and a headrest portion provided behind the occupant's head.

[0151] The rear seat 230 is a long seat arranged behind the driver's seat 210 and the passenger seat 220 .

[0152] The rear seat 230 is capable of seating two passengers side by side in a transverse manner, for example.

[0153] The rear seat 230 includes a cushion portion on which the buttocks and thighs of the occupant are placed, a seat back portion disposed behind the back of the occupant, and a headrest portion provided behind the head of the occupant.

[0154] The right side seating portion of the rear seat 230 is arranged behind the driver's seat 210 , and the left side seating portion is arranged behind the passenger seat 220 .

[0155] 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 and heating device, an infotainment device, and the like.

[0156] Instrument panel 240 is disposed so as to face passengers seated in driver seat 210 and passenger seat 220 .

[0157] exist Fig.10 In the illustrated example, four speakers 170 are provided separately in front, rear, left, and right of vehicle interior 200 , for example.

[0158] In the following description, each speaker 170 is denoted by a suffix corresponding to the position.

[0159] Right front speaker 170FR is disposed near the right end portion of instrument panel 240 .

[0160] Speaker 170FR is a directional speaker directed toward the head (ear) of the occupant sitting in driver's seat 210 .

[0161] The left front speaker 170FL is arranged near the left end portion of the instrument panel 240 .

[0162] Speaker 170FL is a directional speaker directed toward the head (ear) of the occupant sitting in passenger seat 220 .

[0163] The right rear speaker 170RR is disposed in the headrest portion of the driver's seat 210 .

[0164] Speaker 170RR is a directional speaker that is directed toward the head (ear) of the occupant sitting on the right side of rear seat 230 .

[0165] The left rear speaker 170RL is disposed in the headrest portion of the passenger seat 220 .

[0166] Speaker 170RL is a directional speaker directed toward the head (ear) of the occupant sitting on the left side of rear seat 230 .

[0167] In the first embodiment, according to the above configuration, when the driver performs a steering operation and the steering angle θ of the wheels W changes, a sound having an amplitude corresponding to the differential value Δθ of the steering angle θ is emitted from the speaker 170 to the occupant.

[0168] Since the sound is masked by the running sound of the vehicle (background noise), it is difficult for the occupants to consciously recognize it as a sound, but it can make the occupants unconsciously anticipate the occurrence of vehicle behavior caused by the occurrence of lateral acceleration and / or yaw rate.

[0169] According to the first embodiment described above, the following effects can be obtained.

[0170] (1) By generating a sound whose sound pressure increases in accordance with an increase in the absolute value of the differential value Δθ of the steering angle θ of the wheel W of the steering device, the occupants can be made aware of the occurrence of the behavior by the sound at the beginning of the steering process before the vehicle actually generates lateral acceleration, yaw rate, roll angle, etc.

[0171] This improves the predictability of the vehicle behavior by the occupants, and prevents the occupants from feeling a sense of abruptness regarding the vehicle behavior.

[0172] Therefore, the occupant can prepare by applying force to the body before the acceleration or the like occurs, and can prevent the seated posture from being unintentionally changed.

[0173] (2) By making the excitation waveform have a main frequency in the frequency band of 100 to 400 Hz, more preferably 150 to 300 Hz, it is possible to use Pacinian corpuscles, which are highly sensitive in the audible range and highly sensitive in terms of skin sensation, etc., so that the occupant's perception of sound based on sound and recognition of skin sensation are improved. Therefore, information can be transmitted to the occupant more reliably.

[0174] (3) By using a logarithmic function to set the gain G1 in accordance with the absolute value of the differential value Δθ of the steering angle θ, a large gain G1 can be set even in a region where the absolute value of the differential value Δθ is relatively small, and information can be appropriately transmitted to the occupant even in the early stage of steering when the steering angle θ and the differential value (steering speed) Δθ are small.

[0175] In addition, in a region where the absolute value of the differential value Δθ is large, it is possible to prevent the output gain from becoming excessively large.

[0176] (4) By setting gain G2 so that the sound pressure generated by the excitation of speaker 170 is not noticeable at the ear of at least one occupant relative to the background noise of the vehicle during driving, the sound generated by the excitation of speaker 170 is buried in the background noise of the vehicle, thereby preventing the occupants from feeling harshness and allowing information to be appropriately transmitted.

[0177] (5) By using the steering angle θ of the wheel W as a parameter related to the steering amount of the steering device, the parameter can be easily and appropriately acquired using a steering angle sensor that is generally provided in any ordinary vehicle.

[0178] <Second embodiment> Next, a second embodiment of the information transmission device to which the present invention is applied will be described.

[0179] In the second embodiment, the vehicle has an automatic driving function that autonomously performs steering operation, acceleration and deceleration operation, and the like without relying on the driving operation of the driver.

[0180] Fig.11It is a diagram schematically showing the configuration of an automatic driving system of a vehicle provided with the information transmission device according to the second embodiment.

[0181] The automatic driving system 300 includes an automatic 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.

[0182] Each of these units includes a microcomputer having an information processing unit such as a CPU, a storage unit such as a RAM and / or a ROM, an input / output interface, and a bus that connects them.

[0183] In addition, the units can communicate with each other via an in-vehicle LAN connection such as a CAN communication system or a direct connection.

[0184] The automatic driving control unit 310 recognizes the environment around the vehicle using various sensors such as a stereo camera device, a millimeter wave radar device, a laser scanner device, and a high-precision 3D map.

[0185] The automatic driving control unit 310 generates an automatic driving scenario including information related to the driving route, speed, etc. of the host vehicle based on the recognized environment.

[0186] Based on the autonomous driving scenario, the autonomous driving control unit 310 provides 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, thereby controlling the steering and acceleration and deceleration of the vehicle.

[0187] Instead of the steering input from the driver as in the first embodiment, the electric power steering control unit 90 controls the actuator unit 80 to steer the wheels W based on the requested steering angle instructed by the automatic driving control unit 310 .

[0188] The engine control unit 320 centrally controls the engine and its auxiliary machines, which are the driving power source of the vehicle.

[0189] The engine control unit 320 controls the output of the engine in such a manner that the torque actually generated by the engine matches the requested torque instructed by the automatic driving control unit 310 .

[0190] The transmission control unit 330 centrally controls the transmission and its auxiliary machines for changing the speed (decelerating or increasing) of the rotation of the output shaft of the engine.

[0191] The transmission control unit 330 performs switching between a driving range and a non-driving range, switching between forward and reverse travel, and speed change (speed ratio change) during forward travel, etc., according to an instruction from the automatic driving control unit 310 .

[0192] The brake control unit 340 controls the braking force of the hydraulic service brake provided on each wheel of the vehicle.

[0193] The brake control unit 340 adjusts the brake fluid pressure supplied to the wheel cylinder of each wheel according to the requested braking force instructed by the automatic driving control unit 310, thereby generating the required braking force.

[0194] In the second embodiment, even during automatic driving when the driver basically does not perform any steering operation, the requested steering angle transmitted from the automatic driving control unit 310 to the electric power steering control unit 90 is used as an input to the information transmission device 100 (a parameter related to the steering angle of the steering device), and a first gain adjustment is performed based on its differential value.

[0195] According to the second embodiment described above, even in a vehicle that performs automatic driving, by generating a sound corresponding to the absolute value of the differential value of the steering angle when steering based on automatic driving control starts, it is possible for the occupants to foresee the occurrence of vehicle behavior accompanied by the occurrence of lateral acceleration, yaw rate, roll angle, etc., and it is possible to prevent the occupants from feeling abrupt about the vehicle's behavior.

[0196] (Variation) The present invention is not limited to the above-described embodiments, and various modifications and changes are possible, which are also within the technical scope of the present invention.

[0197] (1) The configurations of the information transmission device and the vehicle are not limited to the above-described embodiments, and can be modified as appropriate.

[0198] For example, the hardware configuration of the information transmission device and the specific method of adjusting the gain of the excitation waveform are not limited to the configurations of the respective embodiments, and can be modified as appropriate.

[0199] (2) In each embodiment, for example, the steering angle (the actual steering angle detected by the steering angle sensor or the requested steering angle in the automatic driving control) is used as a parameter related to the steering amount of the steering device. However, the parameter is not limited thereto and can be changed as appropriate.

[0200] For example, it can be configured to have at least one of a steering torque (input torque) input by a driver, an operation amount of an actuator for steering wheels (for example, a rotation amount of a motor), an output instruction value for the actuator, and the like.

[0201] (3) The present invention is not limited to being applied to a vehicle having a steering device in which an operating member such as a steering wheel is mechanically connected to a steering mechanism such as a steering gear box as in the various embodiments, but can also be applied to a vehicle having a steer-by-wire steering device in which a steering wheel or the like is not mechanically connected to a steering mechanism. In this case, the actual steering angle of the front wheels and the state of the steering mechanism (for example, the rotation angle position of the pinion and / or the movement amount of the rack shaft) can be used as parameters related to the steering amount of the steering device.

[0202] (4) In each embodiment, as an example, the level of the background noise of the vehicle is acquired using a microphone, but the present invention is not limited thereto and the level of the background noise may be acquired using other methods. For example, the level of the background noise may be estimated based on the acceleration of the unsprung portion of the vehicle related to the input from the road surface and the output value of the torque sensor of the steering device (torsion bar torque).

Claims

1. An information transmission device, characterized in that: The vehicle is provided with a steering device for steering wheels, The information transmission device comprises: a parameter detection unit for detecting a parameter related to a steering amount of the steering device; an excitation waveform generating unit that generates an excitation waveform; an excitation unit for exciting the air around the occupant using the excitation waveform; as well as A gain adjustment unit increases the output gain of the excitation waveform in accordance with an increase in the absolute value of the differential value of the parameter.

2. The information transmission device according to claim 1, characterized in that: The excitation waveform has a main frequency included in a frequency band of 100 to 400 Hz.

3. The information transmission device according to claim 1 or 2, characterized in that: An increase rate of the output gain in the gain adjustment unit with respect to an increase in the absolute value of the differential value is maximum in a region where the absolute value of the differential value is small, and decreases in accordance with an increase in the absolute value of the differential value.

4. The information transmission device according to claim 1 or 2, characterized in that: The gain adjustment unit sets the output gain so that the sound pressure generated by the excitation of the excitation unit is not noticeable at the ear of at least one occupant relative to background noise during travel of the vehicle.

5. The information transmission device according to claim 1 or 2, characterized in that: The parameter includes at least one of a steering angle of the steering device, an input torque to the steering device, an operation amount of an actuator for steering the wheels, and an output instruction value for the actuator.

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