Information presentation device

Abstract

The present invention addresses the problem of providing an information presentation device that improves the cognition of information relating to a steering angle even when a steering gear ratio is variable. An information presentation device (200) provided in a vehicle having a steering device that steers wheels and changes a steering gear ratio is configured to comprise: a steering operation amount detection unit (112) that detects a steering operation amount by a driver; a steering gear ratio detection unit (10) that detects a steering gear ratio; an excitation waveform generation unit (210) that generates an excitation waveform; an excitation unit (270) that excites air around the occupant and / or a member in contact with the occupant using an excitation waveform; and a gain adjustment unit (230) that increases the output gain of the excitation waveform in accordance with an increase in the absolute value of the differential value of the value obtained by multiplying the reciprocal of the steering gear ratio by the steering operation amount.

Description

Technical Field

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

[0002] In vehicles such as automobiles, as a technology related to outputting sound to passengers according to the state of the vehicle, for example, Patent Document 1 describes a method of presenting the steering amount of a steering wheel by making a 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 is recorded that the sound pitch becomes higher as the steering amount increases, or that the steering amount of the steering wheel is presented by changing the intensity, pitch, timbre, sound pressure, frequency, position of the sound image, etc.

[0004] Patent document 2 describes a vehicle music generating device that simply generates music that reflects the behavior of a vehicle and the operation of a driver. The vehicle music generating device 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 respective information and controls output or output stop.

[0005] Prior art literature 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 A vehicle with a variable steering ratio (the deceleration rate of the front wheel steering angle relative to the steering wheel angle) can change the ratio according to the steering angle range and / or vehicle speed to achieve characteristics that match the scene.

[0007] For example, in a low speed range, by reducing the gear ratio to set it to a fast speed, good handling and a light feeling can be obtained. On the other hand, in a high speed range, by increasing the gear ratio to set it to a slow speed setting, high stability and smooth vehicle characteristics can be achieved.

[0008] However, in a slippery scene such as on a snowy road, it is easy to cause a disordered behavior (slipping, spinning behavior) in a low-speed range. In this case, it is necessary to control the behavior by correcting the steering by countersteering or the like. At this time, in the case of a vehicle set to a fast gear ratio in a low speed range, the steering wheel operation resolution must be finely controlled, which makes driving difficult.

[0009] On the other hand, it is also conceivable to set the gear ratio to a slow speed, but in this case, the original advantage of the variable gear ratio is lost.

[0010] In addition, it is also conceivable to flexibly change the gear ratio by determining the vehicle behavior. However, in this case, the reproducibility of the vehicle behavior based on the steering angle decreases, which may cause the driver to feel uneasy.

[0011] In view of the above-mentioned problems, an object of the present invention is to provide an information presenting device that improves the recognition of information related to the steering angle even when the steering gear ratio is variable.

[0012] Technical Solution In order to solve the above-mentioned problems, an information prompting device of one embodiment of the present invention is characterized in that it is arranged in a vehicle having a steering device that steers wheels and changes a steering gear ratio, and the information prompting device comprises: a steering operation amount detection unit, which detects the steering operation amount of a driver; a steering gear ratio detection unit, which detects the steering gear ratio; an excitation waveform generation unit, which generates an excitation waveform; an excitation unit, which uses the excitation waveform to excite at least one of the air around the occupant and the components in contact with the occupant; and a gain adjustment unit, which increases the output gain of the excitation waveform in accordance with an increase in the absolute value of the differential value of the value obtained by multiplying the inverse of the steering gear ratio and the steering operation amount.

[0013] 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.

[0014] 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.

[0015] In addition, by increasing the output gain of the excitation waveform in accordance with the increase in the absolute value of the differential value obtained by multiplying the inverse of the steering gear ratio and the steering operation amount, the occupants can properly grasp the information related to the actual steering amount (steering angle) of the steering wheel even in a vehicle with a variable steering gear ratio.

[0016] In addition, by generating an excitation waveform corresponding to the driving operation, the operation amount can be recognized with a finer resolution than the steering angle resolution originally possessed by the driver, thereby enabling more precise control, thereby improving controllability even when the steering gear ratio is set to a fast setting, thereby making driving easier.

[0017] In the present invention, the excitation waveform may have a main frequency within a frequency band of 100 to 400 Hz.

[0018] 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.

[0019] Here, more preferably, by setting the main frequency in a frequency band of 150 to 300 Hz, a region where the receptor has better sensitivity can be used, thereby promoting the above-mentioned effect.

[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 when the vehicle is traveling.

[0021] According to this, the sound generated by the excitation of the excitation unit is buried in the background noise of the vehicle, so that the occupants can be prevented from feeling the sound as being harsh, and information can be appropriately transmitted.

[0022] In the present invention, an internal pressure detection unit for detecting the internal pressure of the tire of the wheel may be provided, and the gain adjustment unit may increase the output gain in accordance with an increase in the internal pressure of the tire.

[0023] The steering torque gradient of the car changes according to the tire pressure. Since the driver determines the steering wheel operation amount based on the steering torque gradient in addition to the steering angle, if the torque gradient changes, it will cause driving difficulty.

[0024] According to the present invention, by adjusting the output gain of the excitation waveform of the information presenting device based on the monitoring result of the tire internal pressure, it is possible to suppress the change of the torque gradient felt by the driver and ensure the ease of driving.

[0025] In the present invention, a low visibility state detection unit for detecting a low visibility state around the host vehicle may be provided, and the gain adjustment unit may increase the output gain in response to the detection of the low visibility state.

[0026] When a person is driving, vision is the main information, and the person drives by relying on vision. The person drives by using hearing and touch to supplement the driving perception, and repeating the process of judgment and operation.

[0027] According to the present invention, considering that the ratio of relying on auxiliary hearing and touch becomes higher under the condition of poor visibility, by increasing the output gain of the excitation waveform of the information presentation device, the amount of information obtained from hearing and touch can be increased, thereby ensuring driving ease.

[0028] Technical Effects As described above, according to the present invention, it is possible to provide an information presenting device that improves the recognizability of information related to the steering angle even when the steering gear ratio is variable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a diagram schematically showing a system configuration of a vehicle having an embodiment to which the information presenting device of the present invention is applied.

[0030] Figure 2 It is a diagram schematically showing the structure of a steering device of a vehicle including the information presenting device according to the embodiment.

[0031] Figure 3 This is a diagram schematically showing an example of the relationship between the vehicle speed and the steering gear ratio.

[0032] Figure 4 This is a diagram schematically showing an example of the relationship between the steering angle and the steering gear ratio.

[0033] Figure 5 It is a diagram schematically showing a system configuration of an information presentation device according to an embodiment.

[0034] Figure 6 It is a diagram schematically showing an example of an excitation waveform in the embodiment.

[0035] Figure 7 This is a diagram schematically showing the timing of electrical pulses emitted by a receptor when stimulated.

[0036] Figure 8 Graphs showing the distribution of the sensitivity of Pacinian corpuscles and Meissner corpuscles with respect to frequency.

[0037] Fig. 9 FIG. 1 is a diagram schematically showing an example of gain adjustment performed by the first gain adjustment unit.

[0038] Fig.10 FIG. 1 is a diagram schematically showing an example of a history of output from a microphone.

[0039] Fig.11 This is a diagram showing an example of the relationship between the sound pressure of background noise and the frequency.

[0040] Fig.12 FIG. 1 is a diagram schematically showing an example of gain adjustment performed by the second gain adjustment unit.

[0041] Fig.13It is a diagram schematically showing the arrangement in a vehicle cabin of a vehicle in which the information presenting device according to the embodiment is installed.

[0042] Explanation of symbols DETAILED DESCRIPTION

[0043] Hereinafter, an embodiment of the information presentation device to which the present invention is applied will be described.

[0044] The information presentation device according to the embodiment is installed in a vehicle such as a four-wheeled passenger car, for example.

[0045] Figure 1 It is a diagram schematically showing a system configuration of a vehicle including the information presenting device according to the embodiment.

[0046] like Figure 1 As shown, the vehicle 1 includes a steering control unit 10 , a tire pressure monitoring device 20 , an environment recognition unit 30 , an information presenting device 200 , and the like.

[0047] The steering control unit 10 centrally controls a steering device 100 as a steer-by-wire steering system.

[0048] The configuration of the steering device 100 will be described in detail later.

[0049] The tire internal pressure monitoring device 20 is a device (internal pressure detection unit) that monitors the internal pressure (air pressure) of the tires of the vehicle 1 .

[0050] The tire internal pressure monitoring device 20 includes, for example, a communication device that receives information wirelessly transmitted from an internal pressure sensor provided on a valve cap or the like of the tire.

[0051] The environment recognition unit 30 is a device that recognizes the environment around the host vehicle using various sensors.

[0052] For example, a stereo camera device 31 , an illuminance sensor 32 , a rainfall sensor 33 , and the like are connected to the environment recognition unit 30 .

[0053] The stereo camera device 31 is an imaging device including a pair of stereo cameras disposed toward the front of the host vehicle.

[0054] The illuminance sensor 32 is a sensor that detects the illuminance around the host vehicle.

[0055] The rain sensor 33 is a sensor that detects a rain state based on, for example, vibration of the front windshield.

[0056] The environment recognition unit 30 can recognize a state in which the visibility of the field of view around the host vehicle is reduced based on the outputs of the various sensors.

[0057] The environment recognition unit 30 cooperates with the various sensors to function as a low visibility state detection unit that detects a low visibility state around the host vehicle.

[0058] The information presenting device 200 is a device that presents information to the occupant using sound based on the behavior of the steering device 100 .

[0059] The configuration of the information presenting device 200 will be described in detail later.

[0060] The vehicle includes a steering device 100 described below in order to steer the right front wheel FWR and the left front wheel FWL as steerable wheels.

[0061] Figure 2 It is a diagram schematically showing the structure of a steering device of a vehicle including the information presenting device according to the embodiment.

[0062] like Figure 2 As shown, the steering device 100 is an electric and steer-by-wire device including a steering wheel 110, a reaction force generating device 120, a rack shaft 130, a rack housing 140, tie rods 150, a housing 160, an actuator unit 170, and the like.

[0063] The steering wheel 110 is an annular operation member (steering input unit) that is rotated by the driver to input a steering operation.

[0064] The steering wheel 110 is arranged in the vehicle cabin so as to face the driver's seat.

[0065] The steering wheel 110 is provided with a steering shaft 111 , a steering wheel angle sensor 112 , and a torque sensor 113 .

[0066] The steering shaft 111 is a rotating shaft whose end is mounted on the steering wheel 110 .

[0067] The steering wheel angle sensor 112 is provided at a middle portion of the steering shaft 111 , and is a steering operation amount detection unit that detects the rotation angle position of the steering shaft 111 (operation amount of the driver).

[0068] The torque sensor 113 is provided at the middle portion of the steering shaft 111 and in a region close to the reaction force generating device 120 relative to the steering wheel angle sensor 112 , and detects the torque applied to the steering shaft 111 (the operating force or holding force of the steering wheel 110 by the driver).

[0069] Outputs of the steering wheel angle sensor 112 and the torque sensor 113 are transmitted to the steering control unit 10 .

[0070] The steering control unit 10 controls the output of the motor 171 of the actuator unit 170 according to the outputs of the steering wheel angle sensor 112 and the torque sensor 113 .

[0071] The reaction force generating device 120 includes an actuator that applies torque to the steering shaft 111 in accordance with a command from the steering control unit 10 to generate a simulated steering reaction force.

[0072] The output shaft portion of the reaction force generating device 120 is connected to the end portion of the steering shaft 111 on the opposite side to the steering wheel 110 side.

[0073] The rack shaft 130 is a columnar member disposed such that the longitudinal direction (axial direction) thereof extends along the vehicle width direction.

[0074] The rack shaft 130 is supported so as to be translatably movable in the vehicle width direction relative to the vehicle body.

[0075] A rack gear 131 that meshes with the pinion gear of the pinion shaft 173 is formed at a portion of the rack shaft 130 .

[0076] The rack shaft 130 drives the rack gear 131 by the pinion gear according to the rotation of the steering shaft 120 , so that the rack shaft 130 moves in translation (straightly) in the vehicle width direction.

[0077] The rack housing 140 is a substantially cylindrical member that supports and accommodates the rack shaft 130 so that the rack shaft 130 can be relatively displaced in the vehicle width direction.

[0078] The rack housing 140 cooperates with the rack shaft 130 , the pinion shaft 173 , etc., thereby constituting a steering gear box.

[0079] Rack housings 141 are provided at both ends of the rack housing 140 .

[0080] The rack housing 141 is a member that allows the tie rod 150 to be displaced relative to the rack housing 140 and prevents foreign matter such as dust from entering the rack housing 140 .

[0081] The rack housing 141 is formed of a resin material such as an elastomer into a flexible bellows shape.

[0082] The tie rod 150 is a shaft-shaped linkage member that connects the end of the rack shaft 130 to the knuckle arm 161 of the housing 160 and rotates the housing 160 about the kingpin axis in conjunction with the translational movement of the rack shaft 130 .

[0083] An inner end portion of the tie rod 150 in the vehicle width direction is swingably connected to an end portion of the rack shaft 130 via a ball joint 151 .

[0084] An outer end portion of the tie rod 150 in the vehicle width direction is connected to a knuckle arm 161 of the housing 160 via a ball joint 152 .

[0085] A turnbuckle mechanism (not shown) for traction adjustment is provided at a connection portion between the tie rod 150 and the ball joint 152 .

[0086] The housing (knuckle) 160 is a member that accommodates a hub bearing that supports the hubs to which the right front wheel FWR and the left front wheel FWL are mounted so as to be rotatable around the axle.

[0087] The housing 160 has a knuckle arm 161 formed to protrude forwardly with respect to the axle.

[0088] The housing 160 is supported so as to be rotatable about a kingpin axis serving as a predetermined rotation center axis.

[0089] The housing 160 is pushed and pulled in the vehicle width direction by the rack shaft 130 via the tie rod 150 , and is thereby rotated about the kingpin axis, thereby steering the right front wheel FWR and the left front wheel FWL.

[0090] The actuator unit 170 is a driving device that rotationally drives the pinion shaft 173 to generate a rack thrust force to perform a steering operation.

[0091] The actuator unit 170 is configured to include a motor 171 , a gear box 172 , a pinion shaft 173 , and the like.

[0092] The motor 171 is an electric actuator that generates a driving force to be applied to the pinion shaft 173 .

[0093] The rotation direction and output torque of the motor 171 are controlled by the steering control unit 10 .

[0094] The output shaft angular position (rotation angle) of the motor 171 is configured to be fed back to the steering control unit 10 .

[0095] The gear box 172 includes a reduction gear train that reduces the speed (amplifies the torque) of the rotation output of the motor 171 and transmits the result to the pinion shaft 173 .

[0096] The pinion shaft 173 is a rotating shaft that is rotationally driven by the motor 171 via the gear box 172 .

[0097] A pinion gear that meshes with the rack gear 131 of the rack shaft 130 to drive the rack shaft 130 is formed at the front end portion of the pinion shaft 173 .

[0098] The steering device 100 is a steer-by-wire device with a variable steering ratio.

[0099] The steering control unit 10 has a function of changing the steering gear ratio by changing the correlation between the rotation angle of the steering wheel 110 (steering wheel angle) detected by the steering wheel angle sensor 112 and the actual steering angle actually adopted by the front wheels.

[0100] The steering gear ratio is the ratio of the change in the steering wheel angle to the change in the actual steering angle. The smaller the value of the steering gear ratio, the faster it is. When the change in the steering wheel angle is equal, the change in the actual steering angle becomes larger.

[0101] Figure 3 This is a diagram schematically showing an example of the relationship between the vehicle speed and the steering gear ratio.

[0102] exist Figure 3 In the figure, the horizontal axis represents the vehicle speed and the vertical axis represents the steering gear ratio.

[0103] like Figure 3 As shown, the steering gear ratio is set small in the low speed range to be a fast characteristic. On the other hand, the steering gear ratio is set to increase as the vehicle speed increases to be a slow setting to ensure the stability of the vehicle.

[0104] Figure 4 This is a diagram schematically showing an example of the relationship between the steering angle and the steering gear ratio.

[0105] exist Figure 4 In the figure, the horizontal axis represents the steering angle (steering wheel angle) and the vertical axis represents the steering gear ratio.

[0106] like Figure 4 As shown, the steering transmission ratio is set large in a region where the steering wheel angle is small, and is set small in a region where the steering wheel angle is large.

[0107] The steering control unit 10 has a Figure 3 , Figure 4 The map created based on the tendency shown in the figure changes the steering ratio of the steering device 100 one by one according to the running state of the vehicle.

[0108] Figure 5 It is a diagram schematically showing a system configuration of an information presentation device according to an embodiment.

[0109] The information presenting device 200 vibrates the air around the ears of the occupant using a speaker 270 disposed in the vehicle cabin, thereby notifying the occupant of a precursor to the occurrence of a vehicle behavior using an acoustic signal.

[0110] The information presentation device 200 includes a waveform generation unit 210 , a differential operation unit 220 , a first gain adjustment unit 230 , a microphone 240 , a sensing value operation unit 250 , a second gain adjustment unit 260 , a speaker 270 , and the like.

[0111] The waveform generation unit 210 generates an excitation waveform which is a waveform of an acoustic signal generated by the speaker 270 .

[0112] Figure 6 It is a diagram schematically showing an example of an excitation waveform in the embodiment.

[0113] exist Figure 6 In the figure, the horizontal axis represents time and the vertical axis represents voltage (amplitude).

[0114] For example Figure 6 As shown in (a) of FIG. 8 , the excitation waveform can be set to a sine wave.

[0115] In addition, for example Figure 6 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.

[0116] In addition, the excitation waveform is not limited to these, and can be changed appropriately.

[0117] 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.

[0118] In the embodiment, the frequency of the excitation waveform can be set to, for example, 100 to 400 Hz, and more preferably has a main frequency in the range of 150 to 300 Hz.

[0119] The reason is described below.

[0120] 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.

[0121] Figure 7 This is a diagram schematically showing the timing of electrical pulses emitted by a receptor when stimulated.

[0122] exist Figure 7 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.

[0123] Merkel cells respond relatively slowly to DC components.

[0124] The moment at which the rate of change (velocity) of the Meissner corpuscle in response to contact pressure occurs.

[0125] Pacinian corpuscles respond to instantaneous changes and have the highest sensitivity among these receptors.

[0126] 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.

[0127] Figure 8 Graphs showing the distribution of the sensitivity of Pacinian corpuscles and Meissner corpuscles with respect to frequency.

[0128] exist Figure 8 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.

[0129] like Figure 8 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.

[0130] Such an area is included in the range of 20 Hz to 20 kHz which is generally set as the audible range of humans.

[0131] As an example, the main frequency of the excitation waveform can be set to 250 Hz.

[0132] The differential operation unit 220 obtains the rotation angle (steering wheel angle) θ of the steering wheel 110 detected by the steering wheel angle sensor 112 from the steering control unit 10. H and the current steering gear ratio R STG Related information.

[0133] The differential operation unit 220 first calculates the steering gear ratio R STG The inverse of the steering wheel angle θ H Multiply (make the steering wheel angle θ H Divide by the steering gear ratio R STG ), to calculate the actual steering angle θ of the front wheels.

[0134] The steering control unit 10 functions as a steering gear ratio detection unit of the present invention.

[0135] Steering wheel angle θ H / Steering gear ratio R STG = Actual steering angle of front wheels θ Then, the differential calculation unit 220 calculates a differential value Δθ obtained by time-differentiating the actual steering angle θ of the front wheels.

[0136] The differential calculation unit 220 transmits the calculated differential values ​​Δθ to the first gain adjustment unit 230 one by one.

[0137] The first gain adjustment unit 230 performs a first gain adjustment, which will be described below, on the fundamental wave of the excitation waveform generated by the waveform generation unit 210 .

[0138] The first gain adjustment changes the gain G1 which is an output gain multiplied by the voltage of the excitation waveform according to the differential value (rate of change per unit time) of the actual steering angle θ (a parameter related to the steering amount) of the front wheels of the steering device 100 .

[0139] Fig. 9 FIG. 1 is a diagram schematically showing an example of gain adjustment performed by the first gain adjustment unit.

[0140] exist Fig. 9 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.

[0141] The gain G1 can be configured to increase in accordance with an increase in the absolute value of the differential value Δθ.

[0142] Furthermore, the increase rate of the gain G1 in the first gain adjustment unit 230 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.

[0143] For example, the gain G1 in the first gain adjustment unit 230 can be calculated from the absolute value of the differential value Δθ of the steering angle θ using a logarithmic function.

[0144] The gain G1 is expressed by the following equation 1, for example.

[0145] 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).

[0146] In addition, the coefficient k is corrected according to the outputs of the tire internal pressure monitoring device 20 and the environment recognition unit 30 .

[0147] The coefficient k is increased and corrected according to an increase in the tire internal pressure detected by the tire internal pressure monitoring device 20 .

[0148] In addition, when the environment recognition unit 30 recognizes that the field of vision around the host vehicle is deteriorated, the coefficient k is increased and corrected.

[0149] For example, when the stereo camera device 31 recognizes a poor field of vision condition such as fog and / or backlight, when the illuminance sensor 32 recognizes a predetermined dark environment such as at night or in a tunnel, and when the rain sensor 33 detects rain, the surrounding field of vision is set to deteriorate and the coefficient k is increased for correction.

[0150] The microphone 240 is a sound collecting device that is disposed in the vehicle compartment and collects background noise in the vehicle compartment.

[0151] Microphone 240 is preferably disposed at a position close to the ear of the occupant, and can be configured to be provided in a headrest portion of a seat, for example.

[0152] The output of the microphone 240 is transmitted to the sensing value calculation unit 250 .

[0153] The sensing value calculation unit 250 extracts a component of a predetermined frequency band from the background noise of the vehicle acquired by the microphone 240 , and transmits the sound pressure of the extracted component to the second gain adjustment unit 260 as a sensing value.

[0154] Fig.10 FIG. 1 is a diagram schematically showing an example of a history of output from a microphone.

[0155] exist Fig.10 In FIG. 2 , the horizontal axis represents time, and the vertical axis represents the sound pressure of the background noise acquired by the microphone 240 .

[0156] The sensing value calculation unit 250 performs a fast Fourier transform (FFT) process on the sound signal of the background noise acquired by the microphone 240 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.

[0157] The extracted frequency band is set to include the main frequency of the excitation waveform output by the waveform generation unit 210 .

[0158] The sensing value calculation unit 250 sets the average sound pressure of the extracted frequency band as the sensing value used in the second gain adjustment.

[0159] Fig.11 This is a diagram showing an example of the relationship between the sound pressure and frequency of background noise.

[0160] exist Fig.11 In the figure, the horizontal axis represents frequency and the vertical axis represents sound pressure.

[0161] The bandpass filter can be configured to extract, for example, a frequency band near the main frequency (250 Hz as an example) of the excitation waveform in the waveform generation unit 210 .

[0162] 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 260 as a sensing value.

[0163] The second gain adjustment unit 260 further performs a second gain adjustment, which will be described below, on the excitation waveform after the first gain adjustment.

[0164] Since the second gain adjustment adjusts the output amplitude of the excitation waveform in response to changes in background noise (drive system noise, aerodynamic noise, road noise, etc.) when the vehicle is traveling, the gain of the excitation waveform changes in response to the sensed value of the noise in the vehicle cabin.

[0165] The second gain adjustment unit 260 performs second gain adjustment based on the output of the sensing value calculation unit 250 .

[0166] The second gain adjustment unit 260 sets the gain G2 based on the sensing value output by the sensing value calculation unit 250 .

[0167] Fig.12 FIG. 1 is a diagram schematically showing an example of gain adjustment performed by the second gain adjustment unit.

[0168] exist Fig.12 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.

[0169] The gain G2 can be configured to increase in accordance with an increase in the sensed value.

[0170] Gain G2 is set so that the sound pressure of the sound based on the excitation amplitude output from speaker 270 is not noticeable relative to the sound pressure of the background noise near the ears of the occupant.

[0171] 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.

[0172] 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.

[0173] 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) The speaker 270 is disposed in the vehicle cabin and is a vibration device that uses an output value A to vibrate the air around the passengers in the vehicle cabin to generate sound.

[0174] The arrangement of the speaker 270 will be described in detail later.

[0175] For example, the speaker 270 may be configured to be shared with a speaker used for sound reproduction of an in-vehicle audio system.

[0176] In addition, a speaker 270 dedicated to the information presenting device 200 may be provided.

[0177] Fig.13It is a diagram schematically showing the arrangement in a vehicle cabin of a vehicle in which the information presenting device according to the embodiment is installed.

[0178] Inside the vehicle cabin 300 , a driver's seat 310 , a passenger seat 320 , a rear seat 330 , an instrument panel 340 , and the like are provided.

[0179] The driver's seat 310 and the passenger seat 320 are front seats provided at the front of the vehicle compartment.

[0180] The driver's seat 310 and the passenger seat 320 are provided side by side in the vehicle width direction.

[0181] exist Fig.13 In the illustrated example, the vehicle is a so-called right-hand drive vehicle as an example, and the driver's seat 310 is provided on the right side and the passenger seat 320 is provided on the left side relative to the left-right center of the vehicle body.

[0182] The driver's seat 310 and the passenger's seat 320 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 disposed behind the occupant's head.

[0183] The rear seat 330 is a bench-like seat disposed behind the driver's seat 310 and the passenger seat 320 .

[0184] The rear seat 330 can accommodate, for example, two passengers sitting side by side in transverse direction.

[0185] The rear seat 330 includes a cushion portion on which the buttocks and thighs of the occupant are placed, a seat back portion arranged behind the back of the occupant, and a headrest portion arranged behind the head of the occupant.

[0186] The right side seating portion of the rear seat 330 is arranged behind the driver's seat 310 , and the left side seating portion is arranged behind the passenger seat 320 .

[0187] The instrument panel 340 is provided near the front end of the vehicle interior 300 and is a component that accommodates, for example, an instrument panel, a ventilation and air conditioning heating device, an infotainment device, and the like.

[0188] The instrument panel 340 is arranged to face passengers seated in the driver's seat 310 and the passenger's seat 320 .

[0189] exist Fig.13 In the illustrated example, four speakers 270 are provided separately in the front, rear, left, and right of the vehicle interior 300 .

[0190] Hereinafter, the reference numerals of the speakers 270 will be described by referring to the symbols corresponding to the positions.

[0191] The right front speaker 270FR is arranged near the right end portion of the instrument panel 340 .

[0192] The speaker 270FR is a directional speaker directed toward the head (ear) of the occupant sitting in the driver's seat 310 .

[0193] The left front speaker 270FL is arranged near the left end portion of the instrument panel 340 .

[0194] Speaker 270FL is a directional speaker directed toward the head (ear) of the occupant sitting in passenger seat 320 .

[0195] The right rear speaker 270RR is arranged in the headrest portion of the driver's seat 310 .

[0196] Speaker 270RR is a directional speaker that is directed toward the head (ear) of the occupant sitting on the right side of rear seat 330 .

[0197] The left rear speaker 270RL is disposed in the headrest portion of the passenger seat 320 .

[0198] Speaker 270RL is a directional speaker that is directed toward the head (ear) of the occupant sitting on the left side of rear seat 330 .

[0199] In the embodiment, with 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 270 to the occupant.

[0200] Since the sound is masked by the running sound of the vehicle (background noise), it is difficult for the occupant to consciously recognize the sound as a sound, but the occupant can unconsciously foresee the occurrence of vehicle behavior accompanied by the occurrence of lateral acceleration and yaw rate.

[0201] According to the above-described embodiment, the following effects can be obtained.

[0202] (1) By generating a sound whose sound pressure increases in accordance with an increase in the absolute value of a differential value of a parameter related to the steering amount of the steering device 100 (so-called steering speed), it is possible to use the sound to make the occupants anticipate the occurrence of behavior at the early stage of steering, before the vehicle 1 actually generates lateral acceleration, yaw rate, roll angle, etc.

[0203] This improves the predictability of the vehicle behavior by the occupants, and prevents the occupants from feeling a sense of abruptness regarding the behavior of the vehicle 1 .

[0204] In addition, by increasing the output gain of the excitation waveform in accordance with the increase in the absolute value of the differential value of the value obtained by multiplying the inverse of the steering gear ratio and the steering operation amount, even in a vehicle 1 with a variable steering gear ratio, the occupants can properly grasp the information related to the actual steering angles of the right front wheel FWR and the left front wheel FWL.

[0205] In addition, by generating an excitation waveform corresponding to the driving operation, the operation amount can be recognized within a finer range than the steering angle resolution originally possessed by the driver, thereby enabling more precise control, thereby improving controllability even when the steering gear ratio is set to a fast setting, thereby making driving easier.

[0206] (2) Since the excitation waveform has a main frequency in the frequency band of 100 to 400 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 occupants' perception of sound and recognition of skin sensation based on sound are improved. Therefore, information can be transmitted to the occupants more reliably.

[0207] (3) By setting 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 the background noise of the vehicle 1 when the vehicle 1 is running, the sound generated by the excitation of the excitation unit is buried in the background noise of the vehicle 1, thereby preventing the occupants from feeling the harshness and enabling information to be appropriately transmitted.

[0208] (4) By adjusting the output gain of the excitation waveform of the information display device based on the monitoring result of the tire internal pressure, it is possible to suppress the change in the torque gradient felt by the driver and ensure driving ease.

[0209] (5) Considering that the rate of reliance on hearing and tactile assistance increases in situations where visibility is poor, increasing the output gain of the excitation waveform of the information presentation device can increase the amount of information obtained from hearing and tactile senses, thereby ensuring ease of driving.

[0210] (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.

[0211] (1) The specific configurations of the information presentation device and the vehicle are not limited to those of the above-described embodiments, and can be modified as appropriate.

[0212] (2) In the embodiment, the excitation waveform is presented to the occupant as acoustic information via the speaker. However, instead of or in addition to this, a member touched by the occupant may be excited to present information to the occupant as tactile vibration.

[0213] (3) In the embodiment, the steering device is a steer-by-wire type device as an example. However, the present invention is also applicable to a steering device with a variable steering ratio other than the steer-by-wire type.

Claims

1. An information prompting device, characterized in that: The vehicle is provided with a steering device for steering wheels and changing the steering gear ratio, The information prompting device comprises: A steering operation amount detection unit that detects the driver's steering operation amount; a steering gear ratio detection unit, which detects the steering gear ratio; an excitation waveform generating unit that generates an excitation waveform; an excitation unit for exciting at least one of air around the occupant and a member in contact with the occupant using the excitation waveform; as well as The gain adjustment unit increases the output gain of the excitation waveform in accordance with an increase in an absolute value of a differential value of a value obtained by multiplying the inverse of the steering gear ratio by the steering operation amount.

2. The information prompting 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 prompting 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 when the vehicle is traveling.

4. The information prompting device according to claim 1 or 2, characterized in that: The information presenting device includes an internal pressure detecting unit for detecting the internal pressure of the tire of the wheel. The gain adjustment unit increases the output gain in accordance with an increase in the tire internal pressure.

5. The information prompting device according to claim 1 or 2, characterized in that: The information presenting device includes a low visibility state detecting unit for detecting a low visibility state around the vehicle. The gain adjustment unit increases the output gain in response to detection of the low visibility state.

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