Vehicle sound generating device

Abstract

To assist a driver in perceiving a change of the force applied to a vehicle and improve the accuracy of driving operation.SOLUTION: The present invention comprises: a controller 10 (sound control unit 11) constituted so as to generate a sound signal that represents a sound and set the localization of a sound; and left and right front speakers 20A and rear speakers 20B for outputting a sound that corresponds to a sound signal the localization of which has been set by the controller 10. The controller 10 sets the localization of a sound on the basis of a change amount per unit time of a physical quantity that correlates to driving operation (pitch rate, torque change amount, roll rate, steering angle speed, etc.), so that the sound image of a frequency component (low frequency component) of at least a portion of the sound is located in a wheel direction where the ground load is increasing in accordance with the driving operation of a driver of a vehicle 2.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a sound generating device for a vehicle, and more particularly to a sound generating device for a vehicle that outputs a predetermined sound while the vehicle is running. [Background technology]

[0002] Conventionally, there is known a technique for outputting simulated engine sounds or motor sounds to a driver in response to a vehicle's driving conditions, such as vehicle speed, and the driver's driving operations, such as accelerator opening (see, for example, Patent Documents 1 and 2).

[0003] In the vehicle interior sound field control device described in Patent Document 1, the signal processing of the sound field control means is controlled according to the driving state, so that the engine sound is reproduced from multiple speakers and the sound field of the engine sound is controlled according to the driving state, thereby generating a vivid engine sound in the vehicle interior that reflects the driving state.

[0004] Furthermore, the active sound effect generating device for vehicles described in Patent Document 2 produces sound effects that reflect the driver's operation of the accelerator pedal, such as by adding a delay to the sound effects output from the rear speakers depending on the amount of change per unit time in the accelerator opening or the accelerator opening itself, thereby outputting sound effects that take into account the time difference between the intake sound and the exhaust sound and by creating a sense of the sound source moving. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-10810 A [Patent Document 2] JP 2013-167851 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology in the above-mentioned patent documents merely reproduces the sounds originally produced by the vehicle, such as the engine sound, and does not allow the driver to perceive changes in the forces acting on the vehicle.

[0007] The present invention has been made to solve such problems, and aims to provide a sound generating device for a vehicle that can help the driver perceive changes in forces acting on the vehicle and improve the accuracy of driving operations. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention provides a sound generating device for a vehicle mounted on a vehicle, comprising a sound control unit configured to generate a sound signal representing a sound and set the localization of the sound, and a sound output unit configured to output a sound corresponding to the sound signal whose localization has been set by the sound control unit, wherein the sound control unit sets the localization of the sound based on the amount of change per unit time of a physical quantity correlated to the driving operation so that the sound image of at least some of the frequency components of the sound is located in the direction of the wheels whose ground load is increasing in response to the driving operation of the vehicle driver.

[0009] According to the present invention configured in this way, the sound image position of at least some of the frequency components of the sound is moved toward the wheel where the ground load is increasing in response to the driver's driving operation, based on the change per unit time of the physical quantity correlated with the driving operation. As a result, when the load of the vehicle is shifted in response to the driving operation, the load shift can be easily perceived by the driver by the movement of the sound image position of the sound. In other words, it is possible to help the driver perceive the change in the force applied to the vehicle, and improve the accuracy of the driving operation.

[0010] In the present invention, preferably, the sound control unit sets the sound localization so that the position of the sound image is not biased in a particular direction relative to the driver when the amount of change per unit time of a physical quantity correlated with driving operation is equal to or less than a predetermined value. According to the present invention configured in this manner, for example, when the driver is holding the steering wheel or accelerator pedal constant and there is no load shift in a specific direction in the vehicle, or if there is a load shift, it is sufficiently small, the sound image position is not biased in a specific direction relative to the driver, so that the driver can more easily perceive the movement of the sound image position when a load shift occurs, and the driver can more easily recognize that the sound output from the sound output unit is a sound related to the load shift of the vehicle.

[0011] In the present invention, preferably, the vehicle runs using a rotational power source including an electric motor and / or an engine, and the sound control unit generates a synthetic sound signal including a plurality of frequencies and sets the sound positioning so that sound images of frequency components other than at least some of the frequency components are located in the direction of the rotational power source. According to the present invention configured in this manner, the driver can easily distinguish between sounds conveying the state of the rotary power source and sounds related to the load movement of the vehicle by changes in the direction from which the sounds come.

[0012] In the present invention, preferably, at least a portion of frequency components for setting the localization based on the amount of change per unit time of a physical quantity correlated with a driving operation has a lower frequency than frequency components other than the at least a portion of frequency components. According to the present invention configured in this manner, the position of the bass sound image, which gives a sense of weight and power, is shifted toward the wheels where the ground load is increasing, making it easier for the driver to perceive that the vehicle load is shifting.

[0013] Also, in the present invention, preferably, the vehicle runs using a rotational power source including an electric motor and / or an engine, the physical quantity correlated with the driving operation includes an output torque of the rotational power source, and the sound control unit sets the positioning of the sound in the fore-and-aft direction of the vehicle based on the amount of change per unit time of the output torque. According to the present invention configured in this manner, control is performed using the output torque of the rotational power source, which changes before the vehicle acceleration and suspension stroke, so that the driver can perceive the movement of the bass sound image position before any change in the vehicle's longitudinal behavior occurs, helping the driver predict changes in the vehicle's longitudinal behavior.

[0014] In the present invention, preferably, the physical quantity correlated with the driving operation includes a steering angle of the vehicle, and the sound control unit sets the localization of the sound in the left-right direction of the vehicle based on the amount of change in the steering angle per unit time. According to the present invention configured in this manner, control is performed using the steering angle, which changes before the vehicle acceleration and suspension stroke, so that the driver can perceive the movement of the bass sound image position before any change in the vehicle's behavior in the lateral direction occurs, helping the driver predict changes in the vehicle's behavior in the lateral direction. Effect of the Invention

[0015] The vehicle sound generating device of the present invention can help the driver to perceive changes in forces acting on the vehicle, thereby improving the accuracy of driving operations. [Brief description of the drawings]

[0016] [Figure 1] 1 is an explanatory diagram of a vehicle sound generating device according to an embodiment of the present invention; [Diagram 2] 1 is a configuration diagram of a vehicle sound generating device according to an embodiment of the present invention. [Figure 3A] 1 is an explanatory diagram of a basic concept of control by a vehicle sound generating device according to an embodiment of the present invention; [Figure 3B] 1 is an explanatory diagram of a basic concept of control by a vehicle sound generating device according to an embodiment of the present invention; [Figure 4] 2 is an explanatory diagram of a flow of a sound generation process in the vehicle sound generation device according to the first embodiment of the present invention. FIG. [Diagram 5] 4 is a flowchart of a sound generation process according to the first embodiment of the present invention. [Figure 6]4 is a first sound pressure level setting map showing the relationship between the motor rotation speed and the sound pressure level according to the embodiment of the present invention. [Figure 7] 5 is a second sound pressure level setting map showing the relationship between the motor torque value and the sound pressure level according to the embodiment of the present invention. [Figure 8A] 4 is a table showing an example of equalizing processing in the sound generation processing according to the first embodiment of the present invention. [Figure 8B] 10 is a table showing another example of the equalizing process in the sound generation process according to the first embodiment of the present invention. [Figure 9] FIG. 11 is an explanatory diagram of a flow of sound generation processing in a vehicle sound generation device according to a second embodiment of the present invention. [Figure 10] 10 is a flowchart of a sound generation process according to a second embodiment of the present invention. [Figure 11] 13 is a third sound pressure level setting map showing the relationship between the amount of change per unit time of a physical quantity correlated with driving operations in the longitudinal direction and the sound pressure level in the second embodiment of the present invention. [Figure 12] 13 is a fourth sound pressure level setting map showing the relationship between the amount of change per unit time of a physical quantity correlated with a driving operation in the left and right direction and a sound pressure level in the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a first embodiment and a second embodiment of the present invention will be described with reference to the accompanying drawings. Note that when there is no need to distinguish between these embodiments, they will be simply referred to as "embodiments", and when they must be distinguished, they will be referred to as "first embodiment" or "second embodiment".

[0018] First, the configuration of a sound generating device for a vehicle of the present invention will be described with reference to Figures 1 and 2. Figure 1 is an explanatory diagram of the sound generating device for a vehicle, and Figure 2 is a diagram of the configuration of the sound generating device for a vehicle.

[0019] As shown in Figures 1 and 2, the vehicle sound generating device 1 of this embodiment includes a controller 10 mounted on a vehicle 2, left and right front speakers 20A that output sound from in front of the driver's seat in the vehicle cabin toward the driver's seat, left and right rear speakers 20B that output sound from behind the driver's seat toward the driver's seat, and a group of various sensors 30 that detect the state of the vehicle 2.

[0020] The vehicle 2 is a vehicle that runs using a rotational power source including an electric motor, an engine, etc., and in this embodiment, it is an electric vehicle (EV) equipped with an electric motor 3, but is not limited to this. The vehicle 2 may be a hybrid vehicle equipped with both an internal combustion engine and an electric motor, or may be a vehicle equipped with only an internal combustion engine.

[0021] The controller 10 is a computer device including a processor, a memory (storage unit 12) for storing various programs, a data input / output device, etc. The controller 10 is communicably connected to other in-vehicle devices via an in-vehicle communication line. The controller 10 is configured to output sound signals to the front speaker 20A and the rear speaker 20B by the processor executing a program based on vehicle information from the sensor group 30. At that time, the processor of the controller 10 functions as a sound control unit 11, as described below.

[0022] The front speaker 20A and the rear speaker 20B are sound output units equipped with an amplifier. The front speaker 20A and the rear speaker 20B receive a sound signal from the controller 10, amplify the sound signal at a predetermined amplification rate, and output a sound based on the sound signal. The front speaker 20A and the rear speaker 20B do not have to be provided inside the vehicle cabin, as long as the sound generated by the front speaker 20A and the rear speaker 20B can be localized to the driver. In this embodiment, the front speaker 20A includes a pair of left and right speakers FrL and FrR, and the rear speaker 20B includes a pair of left and right speakers RrL and RrR, but a greater number of speakers may be provided.

[0023] The sensor group 30 includes a rotation speed sensor 31 that detects the rotation speed of the electric motor 3, a PCM 32 that controls the electric motor 3, a steering angle sensor 33 that detects the steering angle of the vehicle 2 (including the steering angle of the steering wheel and the actual steering angle of the steered wheels), and a motion sensor 34 (e.g., a 3D gyro sensor) that detects at least the pitch rate and roll rate of the vehicle 2. These sensor group 30 transmit signals indicating the detected vehicle information through an in-vehicle communication line. The controller 10 can receive various vehicle information signals from the sensor group 30 through the in-vehicle communication line.

[0024] The vehicle information signal is the motor rotation speed signal S R , motor torque value signal S T , steering angle signal S A , attitude angle signal S M The controller 10 (processor) receives the motor rotation speed signal S R The motor rotation speed R is read from the T The motor torque value T is read from the steering angle signal S A The steering angle speed ωs is read from the M The pitch rate ωp and roll rate ωr are read from the motor torque value T. The motor torque value T is a required motor torque value (or a target motor torque value) for the electric motor 3. In this embodiment, the steering angular velocity ωs is assumed to be positive when the steering wheel is operated counterclockwise. Also, the pitch rate ωp is assumed to be positive when the vehicle 2 is pitching forward. Also, the roll rate ωr is assumed to be positive when the vehicle 2 is rolling to the right.

[0025] Like the controller 10, the PCM 32 is a computer device equipped with a processor, a memory for storing various programs, a data input / output device, etc. The PCM 32 receives a vehicle speed signal, an accelerator opening signal, and other signals via an in-vehicle communication line. The PCM 32 calculates a target acceleration from the current accelerator opening, etc., using an acceleration characteristics map (stored in the memory of the PCM 32) that specifies the relationship between the accelerator opening, gear stage, etc. (or the accelerator opening and its rate of change (accelerator depression speed) and gear stage, etc.) and the target acceleration. Furthermore, the PCM 32 calculates a required motor torque value (or a target motor torque value) for achieving the target acceleration.

[0026] In this embodiment, the motor torque value T is a required motor torque value for the electric motor 3, but it is not limited to this and may be an actual motor torque value actually output by the electric motor 3. However, using the required motor torque value rather than the actual motor torque value can provide a sound output to the driver more quickly in response to the driver's accelerator operation, and is therefore expected to contribute more to improving driving operability. In this respect, it is preferable to use the required motor torque value rather than the actual motor torque value.

[0027] In this embodiment, the controller 10 receives the motor torque value signal S T However, the present invention is not limited to this. As described above, the controller 10 may calculate the motor torque value T from the accelerator opening degree and the like by using an acceleration characteristic map or the like.

[0028] Next, the control by the vehicle sound generating device 1 of this embodiment will be described with reference to Fig. 3A and Fig. 3B. Fig. 3A and Fig. 3B are explanatory diagrams of the basic concept of the control by the vehicle sound generating device 1 of this embodiment. In these Fig. 3A and Fig. 3B, the position and range of the ellipse conceptually represent the sound image position based on the driver. Moreover, the dotted ellipse represents the state before the change when the sound image position or sound pressure level changes, and the solid line represents the state after the change. Furthermore, the double-lined ellipse indicates a higher sound pressure level than the solid-lined ellipse.

[0029] When the vehicle 2 starts accelerating from a stopped state or a state where it is traveling at a constant speed, the inertial force acts on the center of gravity of the vehicle 2, decreasing the load on the front wheels and increasing the load on the rear wheels. That is, a load shift occurs from the front wheels to the rear wheels. Also, when the vehicle 2 starts turning from a straight traveling state, the inertial force acts on the center of gravity of the vehicle 2, decreasing the load on the inner wheels and increasing the load on the outer wheels. In these cases, although the driver can perceive that the vehicle 2 has started accelerating or turning, it is difficult for the driver to perceive the rate of change in acceleration (jerk or jerk) or the shift in load using only the sense of balance of the body. Therefore, in this embodiment, the vehicle sound generating device 1 controls the sound image localization of the sound output from the front speaker 20A and the rear speaker 20B, and changes the direction from which the sound comes to the driver in accordance with the load shift of the vehicle 2, thereby helping the driver perceive the change in force applied to the vehicle.

[0030] Specifically, the controller 10 generates a composite sound of sounds of a plurality of frequencies, and outputs the composite sound to the driver from the left and right front speakers 20A and the left and right rear speakers 20B. When the change amount per unit time of the physical quantity correlated with the driving operation of the driver (for example, the physical quantity correlated with the driving operation in the longitudinal direction of the vehicle 2 includes the pitch angle, the motor torque value, the longitudinal acceleration, etc., and the physical quantity correlated with the driving operation in the lateral direction includes the roll angle, the steering angle, the lateral acceleration, etc.) (for example, for the longitudinal direction of the vehicle 2, the pitch rate, the torque change amount, the longitudinal jerk, etc., and for the lateral direction, the roll rate, the steering angle velocity, the lateral jerk, etc.) is equal to or less than a predetermined value, that is, when the load movement in a specific direction is not occurring in the vehicle 2 or is sufficiently small even if it is occurring, the controller 10 outputs the low frequency components of the synthesized sound that give a sense of weight or strength from the front speaker 20A and the rear speaker 20B so that the sound image position is not biased in a specific direction with respect to the driver (that is, so that the low sound that gives a sense of weight or strength is heard from the driver's surroundings without bias). For example, if the difference in sound pressure level between the front, rear, left and right of the headrest of the driver's seat is less than 4 dB, it can be said that the sound image position is not biased. In addition, the controller 10 sets the positioning of the front speaker 20A and the rear speaker 20B (for example, by lowering the sound pressure level of the high-frequency components output from the rear speaker 20B) so that the sound image position of the high-frequency components of the composite sound is located in the direction of the electric motor 3 (i.e., so that the high-frequency sounds are heard from in front of the driver).

[0031] 3A shows a state in which the vehicle 2 is traveling steadily at a constant vehicle speed or accelerating continuously at a constant acceleration. In this case, the ground load of each wheel of the vehicle 2 is constant, and no load shift occurs in a specific direction. Therefore, the controller 10 outputs low-frequency components of the synthesized sound that give a sense of weight and strength from the front speaker 20A and the rear speaker 20B so that the sound image position is not biased in a specific direction relative to the driver.

[0032] On the other hand, for example, when the vehicle 2 is traveling on a left curve, if the driver depresses the accelerator pedal while turning the steering wheel to the left and starts accelerating, the ground load of the right rear wheel of the vehicle 2 increases as shown in FIG. 3B (i.e., load shifts to the right rear wheel). In this case, when the change amount per unit time of the physical quantity correlated with the driving operation of the driver of the vehicle 2 is larger than a predetermined value, the controller 10 increases the sound pressure level of the low frequency component output by the right rear speaker 20B so that the sound image position of the low frequency component that gives a sense of weight and strength in the synthetic sound is located in the direction of the wheel (here, the right rear wheel) whose ground load is increasing (i.e., so that the driver feels that the source of the low frequency component of the synthetic sound is in the direction of the right rear wheel). In this way, by moving the sound image position of the low frequency sound that gives a sense of weight and strength in the direction of the wheel whose ground load is increasing, the driver can be made to perceive that the load of the vehicle 2 is moving. It is possible to move the sound image positions of all the components of the synthetic sound, not just the low frequency components of the synthetic sound, in the direction of the wheel whose ground load is increasing. Also, the controller 10 may generate a sound of a single frequency and move the sound image position of this sound in the direction of the wheel with an increasing ground load.

[0033] Next, the flow of the sound generation process in the vehicle sound generation device 1 of the first embodiment will be described with reference to Fig. 4. Fig. 4 is an explanatory diagram of the flow of the sound generation process in the vehicle sound generation device 1 of the first embodiment.

[0034] 4, in the sound generation process, the vehicle sound generation device 1 of the first embodiment first sets a plurality of frequencies (frequency setting) based on the motor rotation speed R. Each frequency is set to be proportional to the motor rotation speed R. In other words, the higher the motor rotation speed R, the higher the each frequency becomes.

[0035] Next, the vehicle sound generating device 1 sets the sound pressure level of each frequency based on the motor rotation speed R and the motor torque value (sound pressure setting). Specifically, by referring to a first sound pressure level setting map that defines the relationship between the motor rotation speed R and the sound pressure level, a first sound pressure level p1 according to the motor rotation speed R is set for each frequency, and by referring to a second sound pressure level setting map that defines the relationship between the motor torque value and the sound pressure level, a second sound pressure level p2 according to the motor torque value is set for each frequency. The sum of the first sound pressure level p1 and the second sound pressure level p2 is set as the sound pressure level of the sound of each frequency. Note that, although one each of the first sound pressure level setting map and the second sound pressure level setting map is shown in FIG. 4, in reality, the first and second sound pressure level setting maps are prepared in advance for each of a plurality of frequencies and stored in the storage unit 12.

[0036] Next, the vehicle sound generating device 1 generates a total of four-channel synthetic sound signals, including synthetic sound signals for the front channels for the left and right front speakers 20A and synthetic sound signals for the rear channels for the left and right rear speakers 20B, by synthesizing the sounds of each frequency for which sound pressure has been set (synthetic sound generation process). In the first embodiment, the synthetic sound signals for each channel are generated by synthesizing the sounds of all the frequencies set in the sound pressure setting. In other words, the synthetic sound signals for each channel at this stage are the same.

[0037] Next, the vehicle sound generating device 1 performs equalization and gain adjustment on the synthetic sound signal of each channel. At this time, the vehicle sound generating device 1 sets the localization so that the sound image position of the high frequency component is in front of the driver by lowering the sound pressure level of the high frequency component in the synthetic sound signal of the channel for the left and right rear speakers 20B. In addition, the vehicle sound generating device 1 sets the localization so that the sound image position of the low frequency component is located in the direction of the wheels where the ground load is increasing by adjusting the sound pressure level of the low frequency component in the synthetic sound signal of each channel based on the change per unit time of the physical quantity correlated with the driving operation of the driver.

[0038] Then, the vehicle sound generating device 1 outputs a synthesized sound signal S for the left front speaker 20A (FrL) channel after equalization and gain adjustment. SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR Each of the speakers 20A and 20B receives the synthetic sound signal, amplifies it, and outputs it to the driver as a synthetic sound.

[0039] Next, the sound generation process of the vehicle sound generation device 1 of the first embodiment will be described with reference to Fig. 5 to Fig. 8. Fig. 5 is a flowchart of the sound generation process of the first embodiment, Fig. 6 is a first sound pressure level setting map showing the relationship between the motor rotation speed and the sound pressure level of this embodiment, Fig. 7 is a second sound pressure level setting map showing the relationship between the motor torque value and the sound pressure level of this embodiment, and Fig. 8A and Fig. 8B are tables showing an overview of the equalizing process in the sound generation process of the first embodiment.

[0040] The vehicle sound generation device 1 repeatedly executes the sound generation process shown in FIG. 5 at predetermined time intervals (for example, every 10 ms).

[0041] When the sound generation process is started, the controller 10 first acquires sensor information from the sensor group 30 via the in-vehicle communication line (step S1). As described above, the controller 10 acquires at least the motor rotation speed R, the motor torque value T, the steering angular velocity ωs, the pitch rate ωp, and the roll rate ωr.

[0042] Next, the controller 10 (sound control unit 11) performs a frequency setting process (step S2). In the frequency setting process, a plurality of frequencies are set based on the motor rotation speed R. Specifically, five frequencies f1 to f5 for the motor rotation speed R, which is the primary frequency (fundamental frequency), are set by the following formulas. fk(Hz)=R(Hz)×nk (Formula 1)

[0043] Here, k=1 to 5, and nk is an order relative to the motor rotation speed R. Specifically, for example, n1 is 3.3, n2 is 4, n3 is 5.3, n4 is 6.7, and n5 is 8. For example, the 3.3rd order frequency f1 is a frequency 3.3 times the motor rotation speed R (R (Hz) x 3.3). Note that, although the fundamental frequency is the motor rotation speed R in this embodiment, this is not limiting, and the fundamental frequency may be a frequency that increases with an increase in the motor rotation speed R (for example, a proportional relationship).

[0044] For example, when the motor rotation speed R is 50 Hz (3000 rpm), the frequency f1 is 165 Hz, the frequency f2 is 200 Hz, the frequency f3 is 265 Hz, the frequency f4 is 335 Hz, and the frequency f5 is 400 Hz.

[0045] Next, the controller 10 (sound control unit 11) refers to a first sound pressure level setting map (hereinafter also referred to as "map M1") stored in the storage unit 12, and sets a first sound pressure level p1 for each frequency based on the motor rotation speed R (step S3). As shown in Fig. 6, the map M1 is set for each of the frequencies f1 to f5 of the five orders n1 to n5. The map M1 specifies the first sound pressure levels p1 (dB) of the sounds S1 to S5 of the frequencies f1 to f5 for the motor rotation speed R (rpm).

[0046] In the map M1, the first sound pressure level p1 also increases roughly in accordance with an increase in the motor rotation speed R. In this embodiment, the driver can hardly recognize sounds with a sound pressure level lower than 40 dB, and can recognize sounds with a sound pressure level (audible sound pressure level) of 40 dB or more as a guideline. Therefore, according to the map M1, for example, at frequency f4, the first sound pressure level p1 is set to less than 30 dB when the motor rotation speed R is less than about 2500 rpm, so that the driver cannot hear the sound S4 of frequency f4 during low speed rotation. Therefore, the driver cannot consciously hear the frequency sound of about 30 dB contained in the synthetic sound SC. However, such a frequency sound of about 30 dB may also unconsciously affect the driver's vehicle operation.

[0047] Next, the controller 10 (sound control unit 11) sets the second sound pressure level p2 for each of the frequencies f1 to f5 based on a second sound pressure level setting map (also referred to as "map M2") stored in the storage unit 12 (step S4). As shown in FIG. 7, the map M2 is set for each of the frequencies f1 to f5 of the orders n1 to n5. The map M2 specifies the second sound pressure level p2 (dB) at each of the frequencies f1 to f5 for the motor torque value T (N·m). In the map M2, a positive motor torque indicates that the electric motor 3 is operating in a powering state, and a negative motor torque indicates that the electric motor 3 is operating in a regenerative state.

[0048] In the map M2, the second sound pressure level p2 is a negative value at each frequency f1 to f5, and the second sound pressure level p2 also increases with an increase in the positive motor torque value. Therefore, in this embodiment, the first sound pressure level p1 is set by the motor rotation speed R, and when the driver's acceleration request (accelerator operation) is low, a synthetic sound is generated whose sound pressure level is corrected to be lowered by the second sound pressure level p2. That is, during acceleration, the output level of the sound output by the front speaker 20A and the rear speaker 20B increases as the motor rotation speed R or the motor torque value T increases.

[0049] Furthermore, in the map M2, at frequencies f1 and f3, even if the motor torque value T increases from zero, the second sound pressure level p2 is set not to increase until the increase in the motor torque value T exceeds a predetermined amount. In contrast, at frequencies f2, f4, and f5, when the motor torque value T increases from zero, the second sound pressure level p2 is set to increase approximately in proportion to the increase in the motor torque value T without waiting for the predetermined increase. Therefore, when the driver accelerates the vehicle 2 by operating the accelerator, the sounds of the lower frequencies f1 and f3 are always emphasized and output. That is, during acceleration, at least the lowest sound range (k=1) rises quickly, followed by the higher sound ranges (k=2, 4, 5).

[0050] Next, the controller 10 (sound control unit 11) sets the sum of the first sound pressure level p1 and the second sound pressure level p2 of the sounds S1 to S5 of the frequencies f1 to f5 as the sound pressure levels of the sounds S1 to S5 of the frequencies f1 to f5, and synthesizes the sounds S1 to S5 of the frequencies f1 to f5 whose sound pressures have been set, thereby generating a synthesized sound signal S SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR is generated (step S5).

[0051] Next, the controller 10 (sound control unit 11) outputs the synthesized sound signal S SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR Then, equalization processing is performed individually for each of the above (step S6).

[0052] Fig. 8A shows an adjustment amount when adjusting the sound pressure level of the low frequency components of each channel based on the pitch rate ωp and the roll rate ωr as an example of the equalizing process of the first embodiment. In the example shown in Fig. 8A, the controller 10 (sound control unit 11) uses the pitch rate ωp as the amount of change per unit time of the physical quantity correlating with the driving operation in the forward / rearward direction of the vehicle 2, and the roll rate ωr as the amount of change per unit time of the physical quantity correlating with the driving operation in the left / right direction of the vehicle 2, and performs equalization of each channel based on these amounts of change.

[0053] For example, when the absolute value of the roll rate ωr is less than or equal to a predetermined value ωr0 (-ωr0≦ωr≦ωr0) and the absolute value of the pitch rate ωp is less than or equal to a predetermined value ωp0 (-ωp0≦ωp≦ωp0), that is, when both the roll rate ωr and the pitch rate ωp are sufficiently small and the load transfer in any direction in the vehicle 2 is sufficiently small, the controller 10 (sound control unit 11) does not change the sound pressure level of the low-frequency components in the synthetic sound signal of each channel from the set value in step S5.

[0054] Also, for example, when the roll rate ωr is smaller than a negative predetermined value −ωr0 (ωr<−ωr0, here, when the absolute value of the roll rate of the vehicle 2 to the left is larger than the predetermined value ωr0), that is, when the vehicle 2 is turning to the right and a load transfer from the right to the left of the vehicle 2 occurs, the controller 10 (sound control unit 11) generates a synthesized sound signal S SFL and the synthesized sound signal S for the left rear speaker 20B (RrL) SRL For example, when the pitch rate ωp is greater than a predetermined value ωp0 (ωp0<ωp, here, when the forward pitch rate of the vehicle 2 is greater than the predetermined value ωp0), that is, when the vehicle 2 is decelerating while turning to the right and a load transfer from the rear to the front of the vehicle 2 is also occurring, the controller 10 (sound control unit 11) increases the sound pressure level of the low frequency component in the channel for the left front speaker 20A (FrL). SFL In this way, when the ground load of the left front wheel of the vehicle 2 is increasing, the sound image position of the low frequency components of the composite sound output from the front speaker 20A and the rear speaker 20B is set to be located in the direction of the left front wheel.

[0055] Similarly, the controller 10 (sound control unit 11) adjusts the sound pressure level of the low frequency components in the synthetic sound signal of each channel based on the respective values ​​of the roll rate ωr and pitch rate ωp according to the table shown in Fig. 8A. As a result, the localization of the synthetic sound signal is set so that the sound image of the low frequency components of the synthetic sound output from the front speaker 20A and the rear speaker 20B is located in the direction of the wheels with increasing ground load.

[0056] In another example of the equalizing process of the first embodiment, as shown in FIG. 8B, the controller 10 (sound control unit 11) uses the change amount ΔT of the motor torque value T as the change amount per unit time of the physical amount correlating with the driving operation in the forward / rearward direction of the vehicle 2, and uses the steering angular velocity ωs as the change amount per unit time of the physical amount correlating with the driving operation in the left / right direction of the vehicle 2, and performs equalization of each channel based on these change amounts. Even in this case, the controller 10 (sound control unit 11) adjusts the sound pressure level of the low-frequency components in the synthetic sound signal of each channel based on the respective values ​​of the steering angular velocity ωs and the change amount ΔT of the motor torque value T according to the table shown in FIG. 8B. This allows the localization of the synthetic sound signal to be set so that the sound image of the low-frequency components of the synthetic sound output from the front speaker 20A and the rear speaker 20B is located in the direction of the wheels with increasing ground load.

[0057] In the examples of Figures 8A and 8B, the sound pressure level of the low-frequency components is adjusted depending on which of three divided numerical ranges the pitch rate ωp and roll rate ωr, or the steering angular velocity ωs and the change amount ΔT in the motor torque value T, fall into. However, the sound pressure level of the low-frequency components may be adjusted continuously depending on the pitch rate ωp and roll rate ωr, or the steering angular velocity ωs and the change amount ΔT in the motor torque value T.

[0058] In the equalizing process of the first embodiment, the controller 10 (sound control unit 11) outputs the synthesized sound signal S SRL , S SRRThe sound pressure level of the high frequency components in the channel for the rear speaker 20B is reduced by 40 dB. As shown in Fig. 6 and Fig. 7, the sound pressure level of the synthetic sound is set to a maximum of about 80 dB, so by reducing the sound pressure level by 40 dB in this equalizing process, the sound pressure level of the high frequency components in the channel for the rear speaker 20B becomes smaller than 40 dB. In other words, the driver cannot consciously hear the high frequency components of the sound output from the rear speaker 20B. As a result, the sound image position of the high frequency components of the synthetic sound output from the front speaker 20A and the rear speaker 20B is set to be in front of the driver.

[0059] Next, the controller 10 (sound control unit 11) outputs the synthesized sound signal S SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR The gain adjustment process is performed for each of the channels to adjust the amplitude of the overall synthesized sound of each channel (step S7).

[0060] Then, each of the speakers 20A and 20B receives the synthetic sound signal, performs amplification processing, and outputs the synthetic sound to the driver (step S8).

[0061] Next, the flow of the sound generation process in the vehicle sound generation device 1 of the second embodiment will be described with reference to Fig. 9. Fig. 9 is an explanatory diagram of the flow of the sound generation process in the vehicle sound generation device 1 of the second embodiment.

[0062] 9, in the sound generation process, the vehicle sound generation device 1 of the second embodiment first sets one or more frequencies for each of the channel for the left front speaker 20A (FrL), the channel for the right front speaker 20A (FrR), the channel for the left rear speaker 20B (RrL), and the channel for the right rear speaker 20B (RrR) (frequency setting). Each frequency is set to be proportional to the motor rotation speed R. In other words, the higher the motor rotation speed R, the higher each frequency becomes.

[0063] The frequency of the channel for the rear speaker 20B is a low frequency among the multiple frequencies of the channel for the front speaker 20A. For example, the lowest frequency among the multiple frequencies of the channel for the front speaker 20A is set as the frequency of the channel for the rear speaker 20B. Alternatively, a frequency lower than the frequency for the front speaker 20A may be set. As a result, the high frequency components of the synthesized sound are output only from the front speaker 20A, and the sound image position of the high frequency components is set to be in front of the driver.

[0064] Next, the vehicle sound generating device 1 sets the sound pressure levels of the frequencies set for the channels for the left and right front speakers 20A and the channels for the left and right rear speakers 20B based on the motor rotation speed R, the motor torque value T, the pitch rate ωp or the change amount ΔT of the motor torque value T, and the roll rate ωr or the steering angular velocity ωs (sound pressure setting). Specifically, similar to the first embodiment, a first sound pressure level p1 according to the motor rotation speed R is set for each frequency with reference to a first sound pressure level setting map, and a second sound pressure level p2 according to the motor torque value T is set for each frequency with reference to a second sound pressure level setting map. A common map is used for each channel as the first sound pressure level setting map and the second sound pressure level setting map.

[0065] Furthermore, the vehicle sound generating device 1 sets a third sound pressure level p3 for each frequency according to the change amount ΔT of the pitch rate ωp or the motor torque value T with reference to the third sound pressure level setting map, and sets a fourth sound pressure level p4 for each frequency according to the roll rate ωr or the steering angular velocity ωs with reference to the fourth sound pressure level setting map. The third sound pressure level map and the fourth sound pressure level map are set so that the sound pressure level increases when the parameters of each map (the change amount ΔT of the pitch rate ωp or the motor torque value T, and the roll rate ωr or the steering angular velocity ωs) are larger than a predetermined value. In addition, the third sound pressure level setting map and the fourth sound pressure level setting map are different maps for the channels for the left and right front speakers 20A and the channels for the left and right rear speakers 20B. This makes it possible to set the positioning of the synthetic sound signal so that when a load shift occurs in a specific direction in vehicle 2, the sound pressure level of the low-frequency components of the synthetic sound output from the speaker in the direction of the wheel with increasing ground load increases, in other words, so that the sound image position of the low-frequency components of the synthetic sound moves in the direction of the wheel with increasing ground load.

[0066] The sum of the first sound pressure level p1 to fourth sound pressure level p4 thus set is set to the sound pressure level of each frequency in each channel. Note that, although Fig. 9 shows one each of the first sound pressure level setting map to fourth sound pressure level setting map for each channel, in reality, the first to fourth sound pressure level setting maps are prepared in advance for each frequency of each channel and stored in the storage unit 12.

[0067] Next, the vehicle sound generating device 1 synthesizes the sounds of the respective frequencies of the respective channels for which the sound pressures have been set, to generate a synthesized sound signal S for the left front speaker 20A (FrL) channel. SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR(synthetic sound generation process). In the second embodiment, the frequency set in the frequency setting and the sound pressure level set in the sound pressure setting are different for each channel, so that a different synthetic sound signal is generated for each channel.

[0068] The vehicle sound generating device 1 outputs a synthetic sound signal S SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR Each of the speakers 20A and 20B receives the synthetic sound signal, amplifies it, and outputs it to the driver as a synthetic sound.

[0069] Next, the sound generation process of the vehicle sound generation device 1 of the second embodiment will be described with reference to Fig. 10 to Fig. 12. Fig. 10 is a flowchart of the sound generation process of the second embodiment, Fig. 11 is an example of a third sound pressure level setting map showing the relationship between the amount of change per unit time of a physical quantity correlated with a driving operation of the second embodiment and the sound pressure level, and Fig. 12 is another example of a sound pressure level setting map showing the relationship between the amount of change per unit time of a physical quantity correlated with a driving operation of the second embodiment and the sound pressure level.

[0070] The vehicle sound generation device 1 repeatedly executes the sound generation process shown in FIG. 10 at predetermined time intervals (for example, every 10 ms).

[0071] When the sound generation process is started, the controller 10 first acquires sensor information from the sensor group 30 via the in-vehicle communication line (step S11). As described above, the controller 10 acquires at least the motor rotation speed R, the motor torque value T, the steering angular velocity ωs, the pitch rate ωp, and the roll rate ωr.

[0072] Next, the controller 10 (sound control unit 11) performs a frequency setting process (step S12). In the frequency setting process, multiple frequencies are set for the channels for the left and right front speakers 20A, and one or multiple frequencies are set for the channels for the left and right rear speakers 20B, based on the motor rotation speed R. For example, five frequencies f1 to f5 are set for the channel for the front speaker 20A, as in the first embodiment. On the other hand, the frequency f1 is set for the channel for the rear speaker 20B.

[0073] Next, the controller 10 (sound control unit 11) refers to the first sound pressure level setting map (map M1) stored in the memory unit 12, and sets the first sound pressure level p1 for each frequency set for each channel based on the motor rotation speed R (step S13).

[0074] The first sound pressure level p1 of the channel for the front speaker 20A is set in the same manner as in the first embodiment. That is, as shown in Fig. 6, the first sound pressure level p1 of the channel for the front speaker 20A is set based on a map M1 that defines the first sound pressure level p1 (dB) corresponding to the motor rotation speed R (rpm) for each of five frequencies f1 to f5.

[0075] The first sound pressure level p1 of the channel for the rear speaker 20B is set based on a map M1 that defines the first sound pressure level p1 (dB) for one frequency f1 according to the motor rotation speed R (rpm). This map M1 can be the same as the map M1 (FIG. 6(a)) for setting the first sound pressure level p1 for the frequency f1 of the channel for the front speaker 20A.

[0076] Next, the controller 10 (sound control unit 11) refers to the second sound pressure level setting map (map M2) stored in the memory unit 12, and sets the second sound pressure level p2 of each frequency set for the channel for the front speaker 20A and the second sound pressure level p2 of the frequency set for the channel for the rear speaker 20B based on the motor torque value T (step S14).

[0077] The second sound pressure level p2 of the channel for the front speaker 20A is set in the same manner as in the first embodiment. That is, as shown in Fig. 7, the second sound pressure level p2 of the channel for the front speaker 20A is set based on a map M2 that defines the second sound pressure level p2 (dB) corresponding to the motor torque value T (N m) for each of the five frequencies f1 to f5.

[0078] The second sound pressure level p2 of the channel for the rear speaker 20B is set based on a map M2 that defines the second sound pressure level p2 (dB) corresponding to the motor torque value T (N m) for one frequency f1. This map M2 can be the same as the map M2 (FIG. 7(a)) for setting the second sound pressure level p2 for the frequency f1 of the front channel.

[0079] Next, the controller 10 (sound control unit 11) refers to the third sound pressure level setting map (map M3) stored in the storage unit 12, and sets the third sound pressure level p3 of the frequency set for each channel based on the pitch rate ωp or the change amount ΔT of the motor torque value T (step S15). The third sound pressure level p3 is set based on the map M3 that defines the third sound pressure level p3 (dB) corresponding to the pitch rate ωp for one frequency f1 as shown in Figures 11(a) and (b), or based on the map M3 that defines the third sound pressure level p3 (dB) corresponding to the change amount ΔT of the motor torque value T for one frequency f1 as shown in Figures 11(c) and (d).

[0080] 11(a) and (b), in the map M3 that specifies the third sound pressure level p3 (dB) according to the pitch rate ωp, when the pitch rate ωp is greater than a predetermined value (approximately 5 deg / s in FIG. 11(a)), the third sound pressure level p3 of the channel for the left and right front speakers 20A (FrL, FrR) is set to increase by 15 dB in a stepped manner. Therefore, when the pitch rate ωp toward the front of the vehicle 2 exceeds the predetermined value and a load shift occurs from the rear to the front of the vehicle 2, the sound pressure level of the low frequency components of the composite sound output from the left and right front speakers 20A increases, and the localization is set so that the sound image position of the low frequency components of the composite sound is located in front of the driver.

[0081] Furthermore, when the absolute value of the pitch rate ωp is equal to or less than a predetermined value (−5 deg / s≦ωp≦5 deg / s in FIGS. 11(a) and (b)), the third sound pressure level p3 is set to remain at 0 and not increase. Furthermore, when the pitch rate ωp is smaller than a predetermined value (approximately −5 deg / s in FIG. 11(b)), the third sound pressure level p3 of the channel for the left and right rear speakers 20B (RrL, RrR) is set to increase by 15 dB in a stepped manner. Therefore, when the pitch rate ωp toward the rear of the vehicle 2 exceeds a predetermined value and a load shift occurs from the front to the rear of the vehicle 2, the sound pressure level of the low-frequency components of the composite sound output from the left and right rear speakers 20B increases, and the sound image position of the low-frequency components of the composite sound is set to be located behind the driver.

[0082] 11(c) and (d), the third sound pressure level p3 (dB) is specified so that when the change ΔT in the motor torque value T is smaller than a predetermined negative value (approximately -250 N·m / s) and a load shift is occurring from the rear to the front of the vehicle 2, the sound pressure level of the low-frequency components of the composite sound output from the left and right front speakers 20A increases, and when the change ΔT in the motor torque value T is greater than a predetermined value (approximately 250 N·m / s) and a load shift is occurring from the front to the rear of the vehicle 2, the sound pressure level of the low-frequency components of the composite sound output from the left and right rear speakers 20B increases.

[0083] Next, the controller 10 (sound control unit 11) refers to a fourth sound pressure level setting map (map M4) stored in the storage unit 12, and sets a fourth sound pressure level p4 of the frequency set for each channel based on the roll rate ωr or the steering angular velocity ωs (step S16). The fourth sound pressure level p4 is set based on the map M4 that defines the fourth sound pressure level p4 (dB) corresponding to the roll rate ωr for one frequency f1 as shown in Figures 12(a) and (b), or based on the map M4 that defines the fourth sound pressure level p4 (dB) corresponding to the steering angular velocity ωs for one frequency f1 as shown in Figures 12(c) and (d).

[0084] 12(a) and (b), in the map M4 that defines the fourth sound pressure level p4 (dB) according to the roll rate ωr, when the roll rate ωr is smaller than a negative predetermined value (approximately −5 deg / s in FIG. 12(a)), the fourth sound pressure level p4 of the channel for the left front speaker 20A (FrL) and the left rear speaker 20B (RrL) is set to increase by 15 dB in a stepped manner. Therefore, when the roll rate ωr to the left of the vehicle 2 exceeds the predetermined value and a load shift occurs from the right to the left of the vehicle 2, the sound pressure level of the low frequency components of the composite sound output from the left front speaker 20A and the left rear speaker 20B increases, so that the sound image position of the low frequency components of the composite sound is set to be located to the left of the driver.

[0085] Moreover, when the absolute value of the roll rate ωr is equal to or less than a predetermined value (−5 deg / s≦ωr≦5 deg / s in FIGS. 12(a) and 12(b)), the fourth sound pressure level p4 is set to remain at 0 and not increase. Furthermore, when the roll rate ωr is greater than a predetermined value (approximately 5 deg / s in FIG. 12(b)), the fourth sound pressure level p4 of the channel for the right front speaker 20A (FrR) and the right rear speaker 20B (RrR) is set to increase by 15 dB in a stepped manner. Therefore, when the roll rate ωr to the right of the vehicle 2 exceeds a predetermined value and a load shift occurs from the left to the right of the vehicle 2, the sound pressure level of the low-frequency components of the composite sound output from the right front speaker 20A and the right rear speaker 20B increases, so that the sound image position of the low-frequency components of the composite sound is set to be located to the right of the driver.

[0086] In addition, in another example shown in Figures 12(c) and (d), the fourth sound pressure level p4 (dB) is specified so that when the steering angular velocity ωs is smaller than a negative predetermined value (approximately -40 deg / s) and a load shift occurs from the right to the left of the vehicle 2, the sound pressure level of the low-frequency components of the composite sound output from the left front speaker 20A and the left rear speaker 20B increases, and when the steering angular velocity ωs is greater than a predetermined value (approximately 40 deg / s) and a load shift occurs from the front left to the right of the vehicle 2, the sound pressure level of the low-frequency components of the composite sound output from the right front speaker 20A and the right rear speaker 20B increases.

[0087] Next, the controller 10 (sound control unit 11) sets the sum of the first sound pressure level p1, the second sound pressure level p2, the third sound pressure level p3, and the fourth sound pressure level p4 of the sounds of each frequency as the sound pressure level of the sounds of each frequency in each channel, and synthesizes the sounds of each frequency for which the sound pressures have been set, thereby generating a synthesized sound signal S for the channel for the left front speaker 20A (FrL). SFL , the synthesized sound signal S for the right front speaker 20A (FrR) SFR , the synthesized sound signal S of the channel for the left rear speaker 20B (RrL) SRL , and the synthesized sound signal S for the right rear speaker 20B (RrR) SRR is generated (step S17).

[0088] Then, the left and right front speakers 20A and the left and right rear speakers 20B each receive the composite sound signal, amplify it, and output it to the driver as a composite sound (step S18).

[0089] Next, the effects of the vehicle sound generation device 1 of this embodiment will be described. The vehicle sound generating device 1 of this embodiment is mounted on a vehicle 2 and has a controller 10 (sound control unit 11) configured to generate a sound signal representing a sound and set the localization of the sound, and left and right front speakers 20A and rear speakers 20B that output sound according to the sound signal whose localization has been set by the controller 10. The controller 10 (sound control unit 11) sets the localization of the sound based on the change per unit time of a physical quantity correlated to the driving operation (for example, for the longitudinal direction of the vehicle 2, pitch rate, torque change amount, longitudinal jerk, etc., and for the lateral direction, roll rate, steering angular velocity, lateral jerk, etc.) so that the sound image of at least some of the frequency components (low frequency components) of the sound is located in the direction of the wheels whose ground load is increasing in response to the driving operation of the driver of the vehicle 2).

[0090] In this embodiment, the sound image position of at least some of the frequency components of the sound is moved toward the wheel where the ground load is increasing in response to the driving operation of the driver, based on the change per unit time of the physical quantity correlated with the driving operation. As a result, when the load of the vehicle 2 is shifted in response to the driving operation, the load shift can be easily perceived by the driver by the movement of the sound image position of the sound. In other words, it is possible to help the driver perceive the change in the force applied to the vehicle, and improve the accuracy of the driving operation.

[0091] Furthermore, in this embodiment, when the amount of change per unit time of a physical quantity correlated with driving operation is equal to or less than a predetermined value, the controller 10 sets the sound localization so that the sound image position is not biased in a particular direction relative to the driver.

[0092] With this configuration, in this embodiment, for example, when the driver is holding the steering wheel or accelerator pedal constant and there is no load shift in a specific direction in the vehicle 2 or if there is a load shift, it is sufficiently small, the sound image position is not biased in a specific direction relative to the driver, so that the driver can more easily perceive the shift in the sound image position when a load shift occurs, and the driver can more easily recognize that the sound output from the left and right front speakers 20A and the rear speaker 20B is a sound related to the load shift of the vehicle 2.

[0093] Furthermore, in this embodiment, the controller 10 generates a synthetic sound signal including multiple frequencies, and sets the sound localization so that the sound image of frequency components (high frequency components) other than at least some of the frequency components (low frequency components) is located in the direction of the electric motor 3 (rotational power source).

[0094] With this configuration, in this embodiment, the driver can easily distinguish between sounds conveying the state of the electric motor 3 (rotational power source) and sounds related to the load movement of the vehicle 2 by changes in the direction from which the sounds come.

[0095] In this embodiment, at least some of the frequency components that set the localization based on the amount of change per unit time of the physical quantity correlated with the driving operation are lower in frequency than the other frequency components.

[0096] With this configuration, in this embodiment, the position of the low-pitched sound image, which gives a sense of weight and power, is moved toward the wheels where the ground load is increasing, making it easier for the driver to perceive that the load of vehicle 2 is shifting.

[0097] In addition, in this embodiment, the physical quantity correlated with the driving operation includes the motor torque value T of the electric motor 3 (rotational power source), and the controller 10 sets the sound positioning in the fore-and-aft direction of the vehicle 2 based on the change ΔT per unit time of the motor torque value T.

[0098] With this configuration, in this embodiment, control is performed using the motor torque value T, which changes before the acceleration and suspension stroke of the vehicle 2, so that the driver can perceive the movement of the bass sound image position before any change in the longitudinal behavior of the vehicle 2 occurs, helping the driver predict changes in the longitudinal behavior of the vehicle 2.

[0099] In this embodiment, the physical quantity correlated with the driving operation includes the steering angle, and the controller 10 sets the sound localization in the left-right direction of the vehicle 2 based on the steering angle velocity ωs.

[0100] With this configuration, in this embodiment, control is performed using the steering angle, which changes before the acceleration and suspension stroke of the vehicle 2, so that the driver can perceive the movement of the low-frequency sound image position before any change in the left-right behavior of the vehicle 2 occurs, helping the driver predict changes in the left-right behavior of the vehicle 2. [Explanation of symbols]

[0101] 1 Vehicle sound generation device 2 Vehicles 3. Electric motor 10 Controller 11 Sound control section 12 Storage section 20A Front Speaker 20B Rear speaker 30 Sensors 31 Rotational speed sensor 32 PCM 33 Steering angle sensor 34 Motion Sensor M1 1st Sound Pressure Level Setting Map M2 2nd Sound Pressure Level Setting Map M3 3rd Sound Pressure Level Setting Map M4 4th sound pressure level setting map

Claims

1. A vehicle sound generating device mounted on a vehicle, a sound control unit configured to generate a sound signal representative of a sound and to set a localization of the sound; a sound output unit that outputs a sound corresponding to the sound signal whose position has been set by the sound control unit, The sound control unit sets the positioning of the sound based on the amount of change per unit time of a physical quantity correlated to the driving operation so that a sound image of at least some of the frequency components of the sound is located in the direction of the wheels whose ground load is increasing in response to the driving operation of the driver of the vehicle.

2. 2. The vehicle sound generating device according to claim 1, wherein the sound control unit sets the sound localization so that the position of the sound image is not biased in a particular direction relative to the driver when a change in the physical quantity per unit time is equal to or less than a predetermined value.

3. The vehicle runs using a rotary power source including an electric motor and / or an engine, 3. The vehicle sound generating device according to claim 1, wherein the sound control unit generates a synthetic sound signal including a plurality of frequencies and sets the sound localization so that a sound image of frequency components other than the at least some of the frequency components is located in a direction of the rotational power source.

4. The vehicle sound generating device according to claim 3 , wherein the at least some frequency components have a lower frequency than frequency components other than the at least some frequency components.

5. The vehicle runs using a rotary power source including an electric motor and / or an engine, the physical quantity correlated with the driving operation includes an output torque of the rotational power source; The sound control unit sets a localization of the sound in a front-rear direction of the vehicle based on an amount of change per unit time of the output torque.

5. A vehicle sound generating device according to claim 1.

6. the physical quantity correlated with the driving operation includes a steering angle of the vehicle; The sound control unit sets a localization of the sound in the left-right direction of the vehicle based on an amount of change in the steering angle per unit time. A sound generating device for a vehicle according to any one of claims 1 to 5.

Images