Active sound effect generating device and active sound effect generating method

Abstract

The invention provides an active sound effect generating device and an active sound effect generating method. An active sound effect generation device (10) that causes a speaker (12) to output a sound effect into a cabin of a vehicle driven by a drive source, the active sound effect generation device being provided with: a signal generation unit (18) that generates a sound effect signal that is a signal for causing the speaker to output the sound effect; an output unit (20) outputs, to the speaker, the sound effect signal generated by the signal generation unit, and when it is determined that the start-up control is in preparation, the signal generation unit generates a sound effect signal for causing the speaker to output a first sound effect having a component of the first frequency as a main component. Therefore, a better active sound effect generating device and an active sound effect generating method can be provided.

Description

Technical Field

[0001] The invention relates to an active sound effect generating device and an active sound effect generating method. Background Art

[0002] Japanese Patent Application No. 4395170 discloses a sound effect generating device that generates a sound effect from a speaker toward a vehicle cabin. Summary of the Invention

[0003] We look forward to better active sound effect generating devices and active sound effect generating methods.

[0004] The purpose of the present invention is to solve the above technical problems.

[0005] A first embodiment of the present invention is an active sound effect generating device that causes a speaker to output a sound effect into a vehicle cabin driven by a driving source. The active sound effect generating device includes a determination unit, a signal generation unit, and an output unit. The determination unit, upon receiving an operation to activate a start control, determines whether the start control is in preparation, wherein the start control is used to improve the acceleration performance of the vehicle when starting. The signal generation unit generates a signal, i.e., a sound effect signal, that causes the speaker to output the sound effect. The output unit outputs the sound effect signal generated by the signal generation unit to the speaker. When the determination unit determines that the start control is in preparation, the signal generation unit generates the sound effect signal that causes the speaker to output a first sound effect, wherein the first sound effect has a component of a first frequency as a main component.

[0006] A second aspect of the present invention is an active sound effect generation method, which causes a speaker to output a sound effect into a vehicle cabin driven by a driving source. The method includes a determination step, a signal generation step, and an output step. In the determination step, when an operation to activate a start control is received, it is determined whether the start control is in preparation, wherein the start control is used to improve the acceleration performance when the vehicle starts; in the signal generation step, a signal, i.e., a sound effect signal, is generated to cause the speaker to output the sound effect; in the output step, the sound effect signal generated in the signal generation step is output to the speaker. When it is determined in the determination step that the start control is in preparation, the signal generation step generates the sound effect signal to cause the speaker to output a first sound effect, wherein the first sound effect has a component of a first frequency as a main component.

[0007] According to the present invention, a better active sound effect generating device and active sound effect generating method can be provided.

[0008] The above-mentioned objects, features and advantages will be easily understood through the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a functional block diagram of an active sound effect generating device in one embodiment.

[0010] Figure 2 This is a functional block diagram of a signal generating unit in one embodiment.

[0011] Figure 3 It is a schematic diagram showing the frequency bands of order sounds and background sounds.

[0012] Figure 4 This is a graph showing the frequency components of the motor sound and the frequency components of the synthesized sound of the motor sound and the sound effect.

[0013] Figure 5 A diagram illustrating the sound effect when launch control is activated.

[0014] Figure 6 This is a functional block diagram showing a first single sound signal generating unit in one embodiment.

[0015] Figure 7 This is a functional block diagram showing a first-order subsonic signal generating unit in one embodiment.

[0016] Figure 8 This is a functional block diagram showing a first background sound signal generating unit in one embodiment.

[0017] Figure 9 This is a flowchart of a sound effect generation process executed in an active sound effect generating device in one embodiment. DETAILED DESCRIPTION

[0018] Conventionally, there is no proposed active sound effect generator capable of outputting a sound effect that gives the driver a sense of excitement into the vehicle cabin when starting control for improving the acceleration performance when the vehicle starts is activated.

[0019] In the active sound effect generating device of the present invention, when the launch control is activated, a sound effect that gives the driver a sense of excitement can be output into the vehicle cabin.

[0020] [One embodiment] [Structure of active sound effect generating device] Figure 1This is a functional block diagram of an active sound effect generator 10 in one embodiment. The active sound effect generator 10 is mounted on a vehicle powered by an electric motor. Examples of such vehicles are battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell electric vehicles (FCEVs).

[0021] The active sound effect generating device 10 is a device that outputs sound effects through a speaker 12 installed in the vehicle cabin of an electric vehicle, thereby increasing the attractiveness of the electric vehicle to the passengers.

[0022] The active sound effect generating device 10 includes a computing unit 14 and a storage unit 16. The computing unit 14 is, for example, a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit).

[0023] The calculation unit 14 functions as a signal generation unit 18 and an output unit 20. The signal generation unit 18 and the output unit 20 are realized by the calculation unit 14 executing a program stored in the storage unit 16.

[0024] At least a portion of the signal generating unit 18 and the output unit 20 may also be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). At least a portion of the signal generating unit 18 and the output unit 20 may also be implemented by an electronic circuit including discrete components.

[0025] The storage unit 16 is composed of a volatile memory (not shown) and a nonvolatile memory (not shown), both of which are computer-readable storage media. Examples of the volatile memory include RAM (Random Access Memory). Examples of the nonvolatile memory include ROM (Read Only Memory) and flash memory. Data and the like are stored in the volatile memory. Programs, tables, and maps are stored in the nonvolatile memory.

[0026] At least a portion of the storage unit 16 may be provided in the aforementioned processor, integrated circuit, etc. At least a portion of the storage unit 16 may be mounted in a device connected to the active sound effect generator 10 via a network.

[0027] The signal generation unit 18 generates a sound effect signal S for outputting a sound effect from the speaker 12. The output unit 20 outputs the sound effect signal S generated by the signal generation unit 18 to the speaker 12. The speaker 12 generates a sound effect corresponding to the sound effect signal S in the vehicle cabin.

[0028] Figure 2 This is a functional block diagram of the signal generator 18 in one embodiment. The signal generator 18 includes a first single-sound signal generator 22, a second single-sound signal generator 24, a third single-sound signal generator 26, a first-order infrasound signal generator 28, a second-order infrasound signal generator 30, a first background sound signal generator 32, a second background sound signal generator 34, a third background sound signal generator 36, a determination unit 38, selection switches 40a to 40h, and a synthesis unit 42.

[0029] The first, second, and third single sounding signal generating units 22, 24, and 26 generate single sounding signals, which are single sounding electrical signals that change according to the start control state and are output from the speaker 12. The start control state will be described in detail later.

[0030] The first single sound signal generating unit 22 generates the first single sound signal Sa1. The first single sound signal Sa1 is a signal having a sound with a component of a relatively low frequency f1 as a main component. The frequency f1 is equivalent to the first frequency of the present invention. The sound with a component of the frequency f1 as a main component indicates that the amplitude of the sound of the frequency f1 is the largest. The state in which the first single sound signal Sa1 is output to the synthesis unit 42 (on) and the state in which the first single sound signal Sa1 is not output to the synthesis unit 42 (off) are switched by selecting the switch 40a. In the following, the single sound with a component of the frequency f1 as a main component is sometimes described as the first single sound or the first sound effect. When the state of the starting control is "preparing", the first single sound is output from the speaker 12 to the vehicle.

[0031] The second single sound signal generating unit 24 generates the second single sound signal Sa2. The second single sound signal Sa2 is a signal having a sound with a component of frequency f2 higher than frequency f1 as a main component. Frequency f2 is equivalent to the second frequency of the present invention. The sound having a component of frequency f2 as a main component indicates that the amplitude of the sound of frequency f2 is the largest. The state in which the second single sound signal Sa2 is output to the synthesis unit 42 (on) and the state in which the second single sound signal Sa2 is not output to the synthesis unit 42 (off) are switched by selecting the switch 40b. In the following, the sound having a component of frequency f2 as a main component is sometimes described as the second single sound or the second sound effect. When the state of the starting control is "preparation completed", the second single sound is output from the speaker 12 to the vehicle.

[0032] The third single sound signal generating unit 26 generates the third single sound signal Sa3. The third single sound signal Sa3 is a signal of a sound having a component of frequency f3 that is different from both frequency f1 and frequency f2 and having it as the main component. Frequency f3 is equivalent to the third frequency of the present invention. The sound having the component of frequency f3 as the main component indicates that the amplitude of the sound of frequency f3 is the largest. The state in which the third single sound signal Sa3 is output to the synthesis unit 42 (on) and the state in which the third single sound signal Sa3 is not output to the synthesis unit 42 (off) are switched by selecting the switch 40c. In the following, the sound having the component of frequency f3 as the main component is sometimes described as the third single sound or the third sound effect. When the state of the starting control is "in operation", the third single sound is output from the speaker 12 to the vehicle.

[0033] The first-order sound signal generating unit 28 and the second-order sound signal generating unit 30 generate order sound signals, which are electrical signals of order sounds that change in conjunction with changes in the motor's rotational speed and are output from the speaker 12. The first background sound signal generating unit 32, the second background sound signal generating unit 34, and the third background sound signal generating unit 36 generate background sound signals, which are electrical signals of background sounds that are not output from the speaker 12 in conjunction with changes in the motor's rotational speed. Figure 3 It is a schematic diagram showing the frequency bands of order sounds and background sounds.

[0034] The first-order subsonic signal generating unit 28 generates a first-order subsonic signal Sb1. The first-order subsonic signal Sb1 is a sound signal composed of a plurality of frequency components in a frequency band within a predetermined range centered around the 24th order frequency of the motor's rotational speed.

[0035] Furthermore, a sound composed of multiple frequency components within a predetermined frequency band centered around the 24th frequency of the motor's rotational speed refers to a sound whose frequency band is centered at the 24th frequency of the motor's rotational speed. Therefore, the amplitude of the sound at the 24th frequency of the motor's rotational speed can be smaller than the amplitudes of sounds at other frequencies.

[0036] exist Figure 3 , a frequency band within a predetermined range centered on the 24th order frequency of the motor rotational speed N1 [rpm] is represented as frequency band A. Selector switch 40d switches between a state in which the first-order subsonic signal Sb1 is output to the synthesizer 42 (ON) and a state in which the first-order subsonic signal Sb1 is not output to the synthesizer 42 (OFF). Hereinafter, a sound composed of multiple frequency components within a predetermined range centered on the 24th order frequency of the motor rotational speed may be referred to as a first-order subsonic.

[0037] The second-order subsonic signal generator 30 generates a second-order subsonic signal Sb2. The second-order subsonic signal Sb2 is a sound signal composed of a plurality of frequency components in a frequency band within a predetermined range centered around the 48th frequency of the motor's rotational speed.

[0038] Furthermore, a sound composed of multiple frequency components within a predetermined frequency band centered around the 48th frequency of the motor's rotational speed refers to a sound whose frequency band is centered at the 48th frequency of the motor's rotational speed. Therefore, the amplitude of the sound at the 48th frequency of the motor's rotational speed can be smaller than the amplitudes of sounds at other frequencies.

[0039] exist Figure 3 , a frequency band within a predetermined range centered on the 48th order frequency of the motor's rotational speed N1 [rpm] is represented as frequency band B. Selector switch 40b switches between a state in which the second-order subsonic signal Sb2 is output to the synthesizer 42 (on) and a state in which the second-order subsonic signal Sb2 is not output to the synthesizer 42 (off). Hereinafter, a sound composed of multiple frequency components within a predetermined range centered on the 48th order frequency of the motor's rotational speed may be referred to as the second-order subsonic. Hereinafter, both the first-order subsonic and the second-order subsonic may be referred to as the fourth sound effect.

[0040] The first background sound signal generating unit 32 generates a first background sound signal Sc1. The first background sound signal Sc1 is a sound signal composed of a plurality of frequency components in a frequency band within a predetermined range centered at frequency f4.

[0041] Furthermore, a sound composed of multiple frequency components within a predetermined frequency band centered around frequency f4 is a sound having frequency f4 at its center. Therefore, the amplitude of the sound at frequency f4 may be smaller than the amplitudes of sounds at other frequencies.

[0042] exist Figure 3, a frequency band within a predetermined range centered on frequency f4 is represented as frequency band C. Selector switch 40f switches between a state where the first background sound signal Sc1 is output to the synthesizer 42 (ON) and a state where the first background sound signal Sc1 is not output to the synthesizer 42 (OFF). Hereinafter, a sound composed of a plurality of frequency components within a predetermined frequency band centered on frequency f4 may be referred to as the first background sound.

[0043] The second background sound signal generating unit 34 generates a second background sound signal Sc2. The second background sound signal Sc2 is a sound signal composed of a plurality of frequency components in a frequency band within a predetermined range centered on the frequency f5.

[0044] Furthermore, a sound composed of multiple frequency components within a predetermined frequency band centered around frequency f5 is a sound having frequency f5 at its center. Therefore, the amplitude of the sound at frequency f5 may be smaller than the amplitudes of sounds at other frequencies.

[0045] exist Figure 3 , a frequency band within a predetermined range centered on frequency f5 is represented as frequency band D. The selector switch 40g switches between a state where the second background sound signal Sc2 is output to the synthesizer 42 (ON) and a state where the second background sound signal Sc2 is not output to the synthesizer 42 (OFF). A sound composed of multiple frequency components within a predetermined frequency band centered on frequency f5 may be described as the second background sound.

[0046] The third background sound signal generating unit 36 generates a third background sound signal Sc3. The third background sound signal Sc3 is a sound signal composed of a plurality of frequency components in a frequency band within a predetermined range centered on the frequency f6.

[0047] Furthermore, a sound composed of multiple frequency components within a predetermined frequency band centered around frequency f6 is a sound having frequency f6 at its center. Therefore, the amplitude of the sound at frequency f6 may be smaller than the amplitudes of sounds at other frequencies.

[0048] exist Figure 3 , a frequency band within a predetermined range centered on frequency f6 is represented as frequency band E. The selector switch 40h switches between a state where the third background sound signal Sc3 is output to the synthesizer 42 (ON) and a state where the third background sound signal Sc3 is not output to the synthesizer 42 (OFF). A sound composed of multiple frequency components within a predetermined frequency band centered on frequency f6 is sometimes referred to as the third background sound.

[0049] The synthesizing unit 42 generates a sound effect signal S based on the first single sound signal Sa1, the second single sound signal Sa2, the third single sound signal Sa3, the first-order subsound signal Sb1, the second-order subsound signal Sb2, the first background sound signal Sc1, the second background sound signal Sc2, and the third background sound signal Sc3.

[0050] Determination unit 38 determines the status of the start control. It identifies four states: "Release," "Preparation in Progress," "Preparation Completed," and "Operational." The start control status is determined based on the accelerator pedal position, brake pedal force, and the cooling water flow rate increase completion flag. Determination of the start control status will be described in detail later.

[0051] The selection switches 40a to 40h are switched according to the state of the start control. By switching the selection switches 40a to 40h, the sound effect output from the speaker 12 can be changed.

[0052] [About order tones and background sounds] When the motor rotates, a sound obtained by synthesizing the first-order subsound, the second-order subsound, the first background sound, the second background sound, and the third background sound is output from the speaker 12 into the vehicle as a sound effect. Figure 4 This is a graph showing the frequency components of the motor sound and the frequency components of the synthesized sound of the motor sound and the sound effect. Figure 4 The graph indicated by the thin line in the middle represents the frequency component of the motor sound, and the graph indicated by the thick line represents the frequency component of the synthesized sound. Figure 4 Indicates that when the motor is at speed N1 (refer to Figure 3 ) frequency components. In addition, the motor sound is not limited to the sound generated by the motor itself. The motor sound may also include the sound generated by the gears rotating synchronously with the motor.

[0053] like Figure 4 As shown in the thin line graph, the sound pressure level of the 24th order frequency component of the motor sound and the sound pressure level of the 48th order frequency component of the motor sound are more prominent than the sound pressure levels of the other frequency components of the motor sound. Therefore, the sound of the 24th order frequency component and the sound of the 48th order frequency component are clearly heard by the occupants of the vehicle, which may cause discomfort to the occupants. Therefore, by generating the first order subsonic and the second order subsonic from the speaker 12, the sound pressure level of the component of the frequency band within a specified range centered on the 24th order frequency and the sound pressure level of the component of the frequency band within a specified range centered on the 48th order frequency are increased (refer to Figure 4 As a result, a synthesized sound can be produced that is linked to the fluctuation in the rotational speed of the motor, with the prominence of the 24th-order frequency component and the 48th-order frequency component being mitigated.

[0054] The order of the frequency component where the sound pressure level is prominent varies depending on the specifications of the motor, the specifications of the transmission, the specifications of the powertrain, etc. Therefore, the order of the frequency component where the sound pressure level is prominent is not limited to the 24th order or the 48th order. In addition, the number of locations where the sound pressure level is prominent varies depending on the specifications of the motor, the specifications of the transmission, the specifications of the powertrain, etc. Therefore, the locations where the sound pressure level is prominent are not limited to two locations (the 24th order or the 48th order). For example, in the case where the sound pressure level is prominent at three locations, in addition to Figure 2 In addition to the first-order sub-sound signal generating unit 28 and the second-order sub-sound signal generating unit 30 shown, the signal generating unit 18 may be provided with a third-order sub-sound signal generating unit (not shown).

[0055] In addition, the vehicle body and the motor sound may resonate, and the sound pressure level of the component of the vehicle body's resonant frequency may be more prominent than the sound pressure levels of other frequency components. Therefore, by causing the speaker 12 to generate the first background sound, the second background sound, and the third background sound, the sound pressure level of the component in the frequency band within a predetermined range centered on the vehicle body's resonant frequency can be increased (see Figure 4 As a result, a synthesized sound with less prominent resonance sound can be obtained.

[0056] The resonant frequency varies depending on the vehicle body, so the center frequencies of the first background sound, the second background sound, and the third background sound are adjusted and determined according to the vehicle body. In addition, the number of resonant frequencies also varies depending on the vehicle body, so the background sound is not limited to the first background sound, the second background sound, and the third background sound. It can also be two or fewer background sounds or four or more background sounds. For example, in the case of two types of background sounds, Figure 2 The selection switch 40h shown in FIG. 4 is used to select a state in which the third background sound is not output to the synthesizing unit 42. For example, when there are four types of background sounds, Figure 1 In addition to the first background sound signal generating unit 32 , the second background sound signal generating unit 34 , and the third background sound signal generating unit 36 shown, the signal generating unit 18 may be provided with a fourth background sound signal generating unit (not shown).

[0057] Furthermore, when the motor rotates, a sound synthesized from the first-order sub-sound and the second-order sub-sound may be output as a sound effect into the vehicle from the speaker 12. That is, the sound effect does not need to include background sound.

[0058] [Sound effect when launching control] Figure 5 This is a diagram explaining the sound effect when the launch control is activated. Figure 5From top to bottom, it shows the timing diagram of the brake pedal force, the timing diagram of the accelerator pedal opening, the timing diagram of the flow rate increase completion mark, the timing diagram of the starting control status, the timing diagram of the motor torque, and the timing diagram of the vehicle speed.

[0059] Launch control improves vehicle acceleration during startup by suppressing drive wheel slip and allowing the motor to output higher-than-normal torque. When launch control is disabled (i.e., normally), the motor torque during vehicle startup is limited to limit L1. On the other hand, when launch control is enabled, the motor torque during vehicle startup is allowed to reach limit L2, which is higher than limit L1. Furthermore, when the vehicle is stopped, the motor torque is limited to limit L3. Limit L3 is the torque limit when the driver simultaneously depresses the brake and accelerator pedals.

[0060] When the vehicle is stopped and the driver steps on the brake pedal and the accelerator pedal at the same time, preparation for start control begins. When preparation for start control begins, the flow rate of cooling water for cooling the electric motor is increased compared to normal. During start control operation, since the electric motor outputs a higher torque than normal, the heat generated by the electric motor increases. Therefore, the flow rate of cooling water is increased to improve the cooling performance of the electric motor. When the increase in the flow rate of cooling water is completed, the flow rate increase completion flag switches from "0" to "1". Thereafter, when the driver releases the brake pedal, start control operates and the vehicle starts. When start control is operating, since the electric motor can output a higher torque than normal, the acceleration performance at start-up is improved compared to the normal time when start control is not operating.

[0061] If the brake pedal force is greater than or equal to threshold value Bth1 and the accelerator pedal opening is greater than or equal to threshold value Ath, determination unit 38 determines that the start control state is "preparing." If the brake pedal force is less than threshold value Bth1 or the accelerator pedal opening is less than threshold value Ath, determination unit 38 determines that the start control state is "released."

[0062] When the flow rate increase completion flag is "1" while the brake pedal force is at least threshold value Bth1 and the accelerator pedal opening is at least threshold value Ath, determination unit 38 determines that the start control state is "preparation completed." After "preparation completed," if the brake pedal force falls below threshold value Bth2, determination unit 38 determines that the start control state is "in progress." When a predetermined time has passed since the start control state was determined to be "in progress," determination unit 38 determines that the start control state is "released."

[0063] If the start control state is determined to be "preparing", a first single sound (first sound effect) is output from the speaker 12. The first single sound is a sound having a relatively low frequency f1 component as a main component, thereby allowing the driver to feel an increase in torque.

[0064] If the start control status is determined to be "preparation complete," a second single tone (second sound effect) is output from speaker 12. This second single tone is a sound with a frequency f2 component, which is higher than frequency f1, as its primary component. By switching from the first sound effect to the second sound effect, the driver can be made aware that start control preparation is complete, allowing the driver to release the brakes for a high-acceleration start. Furthermore, by outputting a higher-frequency tone from speaker 12, it is possible to simulate a state where the engine speed is maintained at a high level in an engine-powered vehicle.

[0065] If the launch control state is determined to be "in operation," the third single tone (third sound effect) is output from speaker 12. When the launch control state is "in operation," the motor is rotating, so the order sound (fourth sound effect) and background sound are output from speaker 12. In other words, a composite sound of the third single tone, the order sound, and the background sound is output from speaker 12. Hereinafter, the composite sound of the third single tone, the order sound, and the background sound may be referred to as the fifth sound effect.

[0066] In this way, in addition to the order sound and background sound normally output, a synthesized sound composed of the third single sound is output from speaker 12. This allows the driver to recognize that acceleration is different from normal acceleration. For example, by setting the frequency f3 of the sound serving as the main component of the third single sound to a value close to the frequency of wind noise in the vehicle, the driver can be given a sense of acceleration.

[0067] [Structure of the Single Sound Signal Generator] Figure 6 1 is a functional block diagram showing the first single sounding signal generating unit 22 in one embodiment. The first single sounding signal generating unit 22 includes a reference signal setting unit 44 , a gain setting unit 46 , and a correction unit 48 .

[0068] The reference signal setting unit 44 sets a reference signal SA1. The reference signal SA1 is a sound signal having a component of frequency f1 as a main component.

[0069] The gain setting unit 46 sets a gain Ga. The gain Ga is set based on the rotational speed of the motor, the output of the motor, the torque of the motor, the accelerator pedal opening, and the acceleration and deceleration of the vehicle.

[0070] The correction unit 48 outputs a first single sounding signal Sa1 obtained by multiplying the reference signal SA1 set by the reference signal setting unit 44 by the gain Ga.

[0071] The difference between the second single sound signal generating unit 24 and the first single sound signal generating unit 22 is that the reference signal set by the reference signal setting unit 44 is a signal of a sound having a component of frequency f2 and using it as the main component. The other structures are the same as the first single sound signal generating unit 22.

[0072] The difference between the third single sound signal generating unit 26 and the first single sound signal generating unit 22 is that the reference signal set by the reference signal setting unit 44 is a signal of a sound having a component of frequency f3 and using it as the main component. The other structures are the same as the first single sound signal generating unit 22.

[0073] [Structure of the Order Sound Signal Generator] Figure 7 1 is a functional block diagram showing the first-order sub-sound signal generator 28 in one embodiment. The first-order sub-sound signal generator 28 includes a reference signal setting unit 50 , a gain setting unit 52 , and a correction unit 54 .

[0074] The reference signal setting unit 50 sets the reference signal SB1 according to the rotation speed of the motor. The reference signal SB1 is a sound signal composed of a plurality of frequency components in a frequency band within a predetermined range centered on the 24th order frequency of the rotation speed of the motor.

[0075] The gain setting unit 52 sets the gain Gb. The gain Gb is set based on the rotational speed of the motor, the output of the motor, the torque of the motor, the accelerator pedal opening, and the acceleration and deceleration of the vehicle.

[0076] The correction unit 54 outputs a first-order subsonic signal Sb1 obtained by multiplying the reference signal SB1 set by the reference signal setting unit 50 by the gain Gb.

[0077] The difference between the second-order infrasound signal generating unit 30 and the first-order infrasound signal generating unit 28 is that the reference signal set by the reference signal setting unit 50 is a sound signal composed of multiple frequency components in a frequency band within a specified range centered on the 48th order frequency of the motor's rotational speed, and the other structures are the same as those of the first-order infrasound signal generating unit 28.

[0078] [Structure of Background Sound Signal Generator] Figure 8 1 is a functional block diagram showing the first background sound signal generating unit 32 in one embodiment. The first background sound signal generating unit 32 includes a reference signal setting unit 56 , a gain setting unit 58 , and a correction unit 60 .

[0079] The reference signal setting unit 56 sets a reference signal SC1. The reference signal SC1 is a sound signal composed of a plurality of frequency components in a frequency band whose center frequency is frequency f4.

[0080] The gain setting unit 58 sets the gain Gc. The gain Gc is set based on the rotational speed of the motor, the output of the motor, the torque of the motor, the accelerator pedal opening, and the acceleration and deceleration of the vehicle.

[0081] The correction unit 60 outputs a first background sound signal Sc1 obtained by multiplying the reference signal SC1 set by the reference signal setting unit 56 by the gain Gc.

[0082] The difference between the second background sound signal generating unit 34 and the first background sound signal generating unit 32 is that the reference signal set by the reference signal setting unit 56 is a sound signal composed of multiple frequency components in a frequency band with a center frequency of frequency f5, and the other structures are the same as the first background sound signal generating unit 32.

[0083] The difference between the third background sound signal generating unit 36 and the first background sound signal generating unit 32 is that the reference signal set by the reference signal setting unit 56 is a sound signal composed of multiple frequency components in a frequency band with a center frequency of frequency f6, and the other structures are the same as the first background sound signal generating unit 32.

[0084] [Sound effect generation processing] Figure 9 4 is a flowchart of the sound effect generation process performed in the active sound effect generator 10 in this embodiment. The sound effect generation process is repeatedly executed at a predetermined cycle while the vehicle is started.

[0085] In step S1, the determination unit 38 determines whether an operation to activate the start control has been received. The operation to activate the start control refers to an operation in which the driver depresses the brake pedal and the accelerator pedal at the same time.

[0086] If it is determined in step S1 that an operation to activate the start control has been received (step S1: YES), the process proceeds to step S2. In step S2, the determination unit 38 determines whether the state of the start control is "in preparation".

[0087] If, in step S2, the start control state is determined to be "Preparing" (step S2: Yes), the process proceeds to step S3. In step S3, the determination unit 38 turns the selector switch 40a to "ON" and the selector switches 40b to 40h to "OFF." Consequently, only the first single sound signal Sa1 is input to the synthesis unit 42, and the synthesis unit 42 generates a sound effect signal S identical to the first single sound signal Sa1. In other words, the sound effect signal S is generated to cause the speaker 12 to output the first single sound (first sound effect). The process then proceeds to step S9.

[0088] If it is determined in step S2 that the state of the start control is not "preparing" (step S2: No), the process proceeds to step S4. In step S4, the determination unit 38 determines whether the state of the start control is "preparing completed".

[0089] If, in step S4, the start control status is determined to be "preparation complete" (step S4: Yes), the process proceeds to step S5. In step S5, the determination unit 38 turns the selector switch 40b "on" and the selector switches 40a, 40c, 40h, and 40c to 40h "off." Consequently, only the second single sound signal Sa2 is input to the synthesizer 42, and the synthesizer 42 generates a sound effect signal S identical to the second single sound signal Sa2. In other words, the sound effect signal S is generated to cause the speaker 12 to output the second single sound (second sound effect). The process then proceeds to step S9.

[0090] In step S4, if it is determined that the state of the start control is not "prepared" (step S4: No), the process proceeds to step S6. In step S6, the determination unit 38 determines whether the state of the start control is "in operation".

[0091] If, in step S6, the start control state is determined to be "in operation" (step S6: Yes), the process proceeds to step S7. In step S7, the determination unit 38 turns the selector switches 40c to 40h "on" and the selector switches 40a and 40b "off." Consequently, the third single-sound signal Sa3, the first-order subsound signal Sb1, the second-order subsound signal Sb2, the first background sound signal Sc1, the second background sound signal Sc2, and the third background sound signal Sc3 are input to the synthesis unit 42. The synthesis unit 42 generates the sound effect signal S, which is a signal synthesized from the third single-sound signal Sa3, the first-order subsound signal Sb1, the second-order subsound signal Sb2, the first background sound signal Sc1, the second background sound signal Sc2, and the third background sound signal Sc3. That is, the sound effect signal S is generated to output a synthesized sound (fifth sound effect) of the third single sound, the first-order second ...

[0092] If it is determined in step S1 that the operation to activate the start control has not been received (step S1: No), the process proceeds to step S8. If it is determined in step S6 that the start control state is not "active" (step S6: No), the process proceeds to step S8.

[0093] In step S8, the determination unit 38 sets the selection switches 40d to 40h to "on" and the selection switches 40a to 40c to "off." Consequently, the first-order infrasound signal Sb1, the second-order infrasound signal Sb2, the first background sound signal Sc1, the second background sound signal Sc2, and the third background sound signal Sc3 are input to the synthesis unit 42. The synthesis unit 42 generates a sound effect signal S, which is a synthesized signal of the first-order infrasound signal Sb1, the second-order infrasound signal Sb2, the first background sound signal Sc1, the second background sound signal Sc2, and the third background sound signal Sc3. That is, the sound effect signal S is generated, which is a synthesized sound of the first-order infrasound, the second-order infrasound, the first background sound, the second background sound, and the third background sound, and is output from the speaker 12. The process then moves to step S9.

[0094] In step S9, the output unit 20 outputs the sound effect signal S to the speaker 12. As a result, the sound effect is output to the vehicle compartment from the speaker 12. Thereafter, the sound effect generation process ends.

[0095] The following supplementary notes are also disclosed regarding the above-mentioned embodiment.

[0096] (Note 1) The active sound effect generating device (10) of the present invention enables a speaker (12) to output a sound effect into a vehicle cabin driven by a driving source. The active sound effect generating device comprises a determination unit (38), a signal generation unit (18) and an output unit (20), wherein the determination unit (38) determines whether the start control is in preparation when receiving an operation to activate the start control, wherein the start control is used to improve the acceleration performance when the vehicle starts; the signal generation unit (18) generates a signal, i.e., a sound effect signal, for causing the speaker to output the sound effect; and the output unit (20) outputs the sound effect signal generated by the signal generation unit to the speaker. When the determination unit determines that the start control is in preparation, the signal generation unit generates the sound effect signal for causing the speaker to output a first sound effect, wherein the first sound effect has a component of a first frequency as a main component.

[0097] (Note 2) In the active sound effect generating device described in Note 1, it may also be that the determination unit further determines whether the preparation for the start control has been completed. When the determination unit determines that the preparation for the start control has been completed, the signal generation unit generates the sound effect signal that causes the speaker to output a second sound effect, wherein the second sound effect has a second frequency component that is higher than the first frequency and uses it as a main component.

[0098] (Note 3) In the active sound effect generating device described in Note 2, it may also be that the determination unit further determines whether the start control is in operation. When the determination unit determines that the start control is in operation, the signal generation unit generates the sound effect signal that causes the speaker to output a third sound effect, wherein the third sound effect has a component of a third frequency that is different from both the first frequency and the second frequency and uses it as a main component.

[0099] (Note 4) In the active sound effect generating device described in Note 2, it may also be that the determination unit further determines whether the start controller is in operation. When the determination unit determines that the start controller is in operation, the signal generation unit generates the sound effect signal that causes the speaker to output the fifth sound effect, wherein the fifth sound effect is a sound effect obtained by synthesizing the third sound effect and the fourth sound effect, the third sound effect has a third frequency component that is different from both the first frequency and the second frequency and uses it as a main component, and the fourth sound effect changes according to the rotational speed of the driving source.

[0100] (Note 5) The active sound effect generation method of the present invention causes a speaker to output a sound effect into a vehicle cabin driven by a driving source. The active sound effect generation method includes a determination step, a signal generation step, and an output step. In the determination step, when an operation to activate a start control is received, it is determined whether the start control is in preparation, wherein the start control is used to improve the acceleration performance when the vehicle starts; in the signal generation step, a signal, i.e., a sound effect signal, is generated to cause the speaker to output the sound effect; in the output step, the sound effect signal generated in the signal generation step is output to the speaker. When it is determined in the determination step that the start control is in preparation, the signal generation step generates the sound effect signal to cause the speaker to output a first sound effect, wherein the first sound effect has a component of a first frequency as a main component.

[0101] The present invention has been described in detail, but the present invention is not limited to the above-mentioned embodiments. These embodiments can be supplemented, replaced, changed, partially deleted, etc. in a manner that does not deviate from the scope of the present invention or in a manner that does not deviate from the scope of the present invention derived from the contents recorded in the technical solution and its equivalents. In addition, these embodiments can also be implemented in combination. For example, in the above-mentioned embodiment, the order of each action and the order of each processing are shown as an example, but are not limited to this. In addition, the same applies when numerical values or mathematical formulas are used in the description of the above-mentioned embodiment.

Claims

1. An active sound effect generating device (10) that causes a speaker (12) to output sound effects into a vehicle compartment driven by a driving source, characterized in that: It has a determination unit (38), a signal generation unit (18) and an output unit (20), wherein: The determination unit (38) determines whether the start control is in preparation when receiving an operation to activate the start control, wherein the start control is used to improve the acceleration performance when the vehicle starts; The signal generating unit (18) generates a signal, namely a sound effect signal, for causing the speaker to output the sound effect; The output unit (20) outputs the sound effect signal generated by the signal generating unit to the speaker, When the determination unit determines that the start control is in preparation, the signal generation unit generates the sound effect signal for causing the speaker to output a first sound effect, wherein the first sound effect has a first frequency component as a main component.

2. The active sound effect generating device according to claim 1, characterized in that: The determination unit further determines whether the preparation for the start control is completed. When the determination unit determines that the preparation for the start control is complete, the signal generation unit generates the sound effect signal for causing the speaker to output a second sound effect, wherein the second sound effect has a second frequency component higher than the first frequency as a main component.

3. The active sound effect generating device according to claim 2, characterized in that: The determination unit further determines whether the start control is in operation. When the determination unit determines that the start control is in operation, the signal generation unit generates the sound effect signal for causing the speaker to output a third sound effect, wherein the third sound effect has a component of a third frequency different from both the first frequency and the second frequency as a main component.

4. The active sound effect generating device according to claim 2, characterized in that: The determination unit further determines whether the start controller is in operation. When the determination unit determines that the start controller is in operation, the signal generation unit generates the sound effect signal to cause the speaker to output a fifth sound effect, wherein the fifth sound effect is a sound effect obtained by synthesizing a third sound effect and a fourth sound effect, the third sound effect having a third frequency component that is different from both the first frequency and the second frequency as a main component, and the fourth sound effect changes according to the rotational speed of the drive source.

5. An active sound effect generation method, wherein a speaker outputs the sound effect into a vehicle compartment driven by a driving source, characterized in that: It has a determination step, a signal generation step and an output step, wherein, In the determining step, when an operation to activate a start control is received, determining whether the start control is in preparation, wherein the start control is for improving acceleration performance when the vehicle starts; In the signal generating step, a signal, namely, a sound effect signal, is generated to cause the speaker to output the sound effect; In the output step, the sound effect signal generated in the signal generation step is output to the speaker, If it is determined in the determining step that the start control is in preparation, the signal generating step generates the sound effect signal for causing the speaker to output a first sound effect, wherein the first sound effect has a first frequency component as a main component.

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